xref: /openbmc/linux/drivers/dma/xilinx/xilinx_dma.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * DMA driver for Xilinx Video DMA Engine
4  *
5  * Copyright (C) 2010-2014 Xilinx, Inc. All rights reserved.
6  *
7  * Based on the Freescale DMA driver.
8  *
9  * Description:
10  * The AXI Video Direct Memory Access (AXI VDMA) core is a soft Xilinx IP
11  * core that provides high-bandwidth direct memory access between memory
12  * and AXI4-Stream type video target peripherals. The core provides efficient
13  * two dimensional DMA operations with independent asynchronous read (S2MM)
14  * and write (MM2S) channel operation. It can be configured to have either
15  * one channel or two channels. If configured as two channels, one is to
16  * transmit to the video device (MM2S) and another is to receive from the
17  * video device (S2MM). Initialization, status, interrupt and management
18  * registers are accessed through an AXI4-Lite slave interface.
19  *
20  * The AXI Direct Memory Access (AXI DMA) core is a soft Xilinx IP core that
21  * provides high-bandwidth one dimensional direct memory access between memory
22  * and AXI4-Stream target peripherals. It supports one receive and one
23  * transmit channel, both of them optional at synthesis time.
24  *
25  * The AXI CDMA, is a soft IP, which provides high-bandwidth Direct Memory
26  * Access (DMA) between a memory-mapped source address and a memory-mapped
27  * destination address.
28  */
29 
30 #include <linux/bitops.h>
31 #include <linux/dmapool.h>
32 #include <linux/dma/xilinx_dma.h>
33 #include <linux/init.h>
34 #include <linux/interrupt.h>
35 #include <linux/io.h>
36 #include <linux/iopoll.h>
37 #include <linux/module.h>
38 #include <linux/of_address.h>
39 #include <linux/of_dma.h>
40 #include <linux/of_platform.h>
41 #include <linux/of_irq.h>
42 #include <linux/slab.h>
43 #include <linux/clk.h>
44 #include <linux/io-64-nonatomic-lo-hi.h>
45 
46 #include "../dmaengine.h"
47 
48 /* Register/Descriptor Offsets */
49 #define XILINX_DMA_MM2S_CTRL_OFFSET		0x0000
50 #define XILINX_DMA_S2MM_CTRL_OFFSET		0x0030
51 #define XILINX_VDMA_MM2S_DESC_OFFSET		0x0050
52 #define XILINX_VDMA_S2MM_DESC_OFFSET		0x00a0
53 
54 /* Control Registers */
55 #define XILINX_DMA_REG_DMACR			0x0000
56 #define XILINX_DMA_DMACR_DELAY_MAX		0xff
57 #define XILINX_DMA_DMACR_DELAY_SHIFT		24
58 #define XILINX_DMA_DMACR_FRAME_COUNT_MAX	0xff
59 #define XILINX_DMA_DMACR_FRAME_COUNT_SHIFT	16
60 #define XILINX_DMA_DMACR_ERR_IRQ		BIT(14)
61 #define XILINX_DMA_DMACR_DLY_CNT_IRQ		BIT(13)
62 #define XILINX_DMA_DMACR_FRM_CNT_IRQ		BIT(12)
63 #define XILINX_DMA_DMACR_MASTER_SHIFT		8
64 #define XILINX_DMA_DMACR_FSYNCSRC_SHIFT	5
65 #define XILINX_DMA_DMACR_FRAMECNT_EN		BIT(4)
66 #define XILINX_DMA_DMACR_GENLOCK_EN		BIT(3)
67 #define XILINX_DMA_DMACR_RESET			BIT(2)
68 #define XILINX_DMA_DMACR_CIRC_EN		BIT(1)
69 #define XILINX_DMA_DMACR_RUNSTOP		BIT(0)
70 #define XILINX_DMA_DMACR_FSYNCSRC_MASK		GENMASK(6, 5)
71 
72 #define XILINX_DMA_REG_DMASR			0x0004
73 #define XILINX_DMA_DMASR_EOL_LATE_ERR		BIT(15)
74 #define XILINX_DMA_DMASR_ERR_IRQ		BIT(14)
75 #define XILINX_DMA_DMASR_DLY_CNT_IRQ		BIT(13)
76 #define XILINX_DMA_DMASR_FRM_CNT_IRQ		BIT(12)
77 #define XILINX_DMA_DMASR_SOF_LATE_ERR		BIT(11)
78 #define XILINX_DMA_DMASR_SG_DEC_ERR		BIT(10)
79 #define XILINX_DMA_DMASR_SG_SLV_ERR		BIT(9)
80 #define XILINX_DMA_DMASR_EOF_EARLY_ERR		BIT(8)
81 #define XILINX_DMA_DMASR_SOF_EARLY_ERR		BIT(7)
82 #define XILINX_DMA_DMASR_DMA_DEC_ERR		BIT(6)
83 #define XILINX_DMA_DMASR_DMA_SLAVE_ERR		BIT(5)
84 #define XILINX_DMA_DMASR_DMA_INT_ERR		BIT(4)
85 #define XILINX_DMA_DMASR_SG_MASK		BIT(3)
86 #define XILINX_DMA_DMASR_IDLE			BIT(1)
87 #define XILINX_DMA_DMASR_HALTED		BIT(0)
88 #define XILINX_DMA_DMASR_DELAY_MASK		GENMASK(31, 24)
89 #define XILINX_DMA_DMASR_FRAME_COUNT_MASK	GENMASK(23, 16)
90 
91 #define XILINX_DMA_REG_CURDESC			0x0008
92 #define XILINX_DMA_REG_TAILDESC		0x0010
93 #define XILINX_DMA_REG_REG_INDEX		0x0014
94 #define XILINX_DMA_REG_FRMSTORE		0x0018
95 #define XILINX_DMA_REG_THRESHOLD		0x001c
96 #define XILINX_DMA_REG_FRMPTR_STS		0x0024
97 #define XILINX_DMA_REG_PARK_PTR		0x0028
98 #define XILINX_DMA_PARK_PTR_WR_REF_SHIFT	8
99 #define XILINX_DMA_PARK_PTR_WR_REF_MASK		GENMASK(12, 8)
100 #define XILINX_DMA_PARK_PTR_RD_REF_SHIFT	0
101 #define XILINX_DMA_PARK_PTR_RD_REF_MASK		GENMASK(4, 0)
102 #define XILINX_DMA_REG_VDMA_VERSION		0x002c
103 
104 /* Register Direct Mode Registers */
105 #define XILINX_DMA_REG_VSIZE			0x0000
106 #define XILINX_DMA_REG_HSIZE			0x0004
107 
108 #define XILINX_DMA_REG_FRMDLY_STRIDE		0x0008
109 #define XILINX_DMA_FRMDLY_STRIDE_FRMDLY_SHIFT	24
110 #define XILINX_DMA_FRMDLY_STRIDE_STRIDE_SHIFT	0
111 
112 #define XILINX_VDMA_REG_START_ADDRESS(n)	(0x000c + 4 * (n))
113 #define XILINX_VDMA_REG_START_ADDRESS_64(n)	(0x000c + 8 * (n))
114 
115 #define XILINX_VDMA_REG_ENABLE_VERTICAL_FLIP	0x00ec
116 #define XILINX_VDMA_ENABLE_VERTICAL_FLIP	BIT(0)
117 
118 /* HW specific definitions */
119 #define XILINX_DMA_MAX_CHANS_PER_DEVICE	0x20
120 
121 #define XILINX_DMA_DMAXR_ALL_IRQ_MASK	\
122 		(XILINX_DMA_DMASR_FRM_CNT_IRQ | \
123 		 XILINX_DMA_DMASR_DLY_CNT_IRQ | \
124 		 XILINX_DMA_DMASR_ERR_IRQ)
125 
126 #define XILINX_DMA_DMASR_ALL_ERR_MASK	\
127 		(XILINX_DMA_DMASR_EOL_LATE_ERR | \
128 		 XILINX_DMA_DMASR_SOF_LATE_ERR | \
129 		 XILINX_DMA_DMASR_SG_DEC_ERR | \
130 		 XILINX_DMA_DMASR_SG_SLV_ERR | \
131 		 XILINX_DMA_DMASR_EOF_EARLY_ERR | \
132 		 XILINX_DMA_DMASR_SOF_EARLY_ERR | \
133 		 XILINX_DMA_DMASR_DMA_DEC_ERR | \
134 		 XILINX_DMA_DMASR_DMA_SLAVE_ERR | \
135 		 XILINX_DMA_DMASR_DMA_INT_ERR)
136 
137 /*
138  * Recoverable errors are DMA Internal error, SOF Early, EOF Early
139  * and SOF Late. They are only recoverable when C_FLUSH_ON_FSYNC
140  * is enabled in the h/w system.
141  */
142 #define XILINX_DMA_DMASR_ERR_RECOVER_MASK	\
143 		(XILINX_DMA_DMASR_SOF_LATE_ERR | \
144 		 XILINX_DMA_DMASR_EOF_EARLY_ERR | \
145 		 XILINX_DMA_DMASR_SOF_EARLY_ERR | \
146 		 XILINX_DMA_DMASR_DMA_INT_ERR)
147 
148 /* Axi VDMA Flush on Fsync bits */
149 #define XILINX_DMA_FLUSH_S2MM		3
150 #define XILINX_DMA_FLUSH_MM2S		2
151 #define XILINX_DMA_FLUSH_BOTH		1
152 
153 /* Delay loop counter to prevent hardware failure */
154 #define XILINX_DMA_LOOP_COUNT		1000000
155 
156 /* AXI DMA Specific Registers/Offsets */
157 #define XILINX_DMA_REG_SRCDSTADDR	0x18
158 #define XILINX_DMA_REG_BTT		0x28
159 
160 /* AXI DMA Specific Masks/Bit fields */
161 #define XILINX_DMA_MAX_TRANS_LEN_MIN	8
162 #define XILINX_DMA_MAX_TRANS_LEN_MAX	23
163 #define XILINX_DMA_V2_MAX_TRANS_LEN_MAX	26
164 #define XILINX_DMA_CR_COALESCE_MAX	GENMASK(23, 16)
165 #define XILINX_DMA_CR_CYCLIC_BD_EN_MASK	BIT(4)
166 #define XILINX_DMA_CR_COALESCE_SHIFT	16
167 #define XILINX_DMA_BD_SOP		BIT(27)
168 #define XILINX_DMA_BD_EOP		BIT(26)
169 #define XILINX_DMA_COALESCE_MAX		255
170 #define XILINX_DMA_NUM_DESCS		255
171 #define XILINX_DMA_NUM_APP_WORDS	5
172 
173 /* Multi-Channel DMA Descriptor offsets*/
174 #define XILINX_DMA_MCRX_CDESC(x)	(0x40 + (x-1) * 0x20)
175 #define XILINX_DMA_MCRX_TDESC(x)	(0x48 + (x-1) * 0x20)
176 
177 /* Multi-Channel DMA Masks/Shifts */
178 #define XILINX_DMA_BD_HSIZE_MASK	GENMASK(15, 0)
179 #define XILINX_DMA_BD_STRIDE_MASK	GENMASK(15, 0)
180 #define XILINX_DMA_BD_VSIZE_MASK	GENMASK(31, 19)
181 #define XILINX_DMA_BD_TDEST_MASK	GENMASK(4, 0)
182 #define XILINX_DMA_BD_STRIDE_SHIFT	0
183 #define XILINX_DMA_BD_VSIZE_SHIFT	19
184 
185 /* AXI CDMA Specific Registers/Offsets */
186 #define XILINX_CDMA_REG_SRCADDR		0x18
187 #define XILINX_CDMA_REG_DSTADDR		0x20
188 
189 /* AXI CDMA Specific Masks */
190 #define XILINX_CDMA_CR_SGMODE          BIT(3)
191 
192 #define xilinx_prep_dma_addr_t(addr)	\
193 	((dma_addr_t)((u64)addr##_##msb << 32 | (addr)))
194 /**
195  * struct xilinx_vdma_desc_hw - Hardware Descriptor
196  * @next_desc: Next Descriptor Pointer @0x00
197  * @pad1: Reserved @0x04
198  * @buf_addr: Buffer address @0x08
199  * @buf_addr_msb: MSB of Buffer address @0x0C
200  * @vsize: Vertical Size @0x10
201  * @hsize: Horizontal Size @0x14
202  * @stride: Number of bytes between the first
203  *	    pixels of each horizontal line @0x18
204  */
205 struct xilinx_vdma_desc_hw {
206 	u32 next_desc;
207 	u32 pad1;
208 	u32 buf_addr;
209 	u32 buf_addr_msb;
210 	u32 vsize;
211 	u32 hsize;
212 	u32 stride;
213 } __aligned(64);
214 
215 /**
216  * struct xilinx_axidma_desc_hw - Hardware Descriptor for AXI DMA
217  * @next_desc: Next Descriptor Pointer @0x00
218  * @next_desc_msb: MSB of Next Descriptor Pointer @0x04
219  * @buf_addr: Buffer address @0x08
220  * @buf_addr_msb: MSB of Buffer address @0x0C
221  * @mcdma_control: Control field for mcdma @0x10
222  * @vsize_stride: Vsize and Stride field for mcdma @0x14
223  * @control: Control field @0x18
224  * @status: Status field @0x1C
225  * @app: APP Fields @0x20 - 0x30
226  */
227 struct xilinx_axidma_desc_hw {
228 	u32 next_desc;
229 	u32 next_desc_msb;
230 	u32 buf_addr;
231 	u32 buf_addr_msb;
232 	u32 mcdma_control;
233 	u32 vsize_stride;
234 	u32 control;
235 	u32 status;
236 	u32 app[XILINX_DMA_NUM_APP_WORDS];
237 } __aligned(64);
238 
239 /**
240  * struct xilinx_cdma_desc_hw - Hardware Descriptor
241  * @next_desc: Next Descriptor Pointer @0x00
242  * @next_desc_msb: Next Descriptor Pointer MSB @0x04
243  * @src_addr: Source address @0x08
244  * @src_addr_msb: Source address MSB @0x0C
245  * @dest_addr: Destination address @0x10
246  * @dest_addr_msb: Destination address MSB @0x14
247  * @control: Control field @0x18
248  * @status: Status field @0x1C
249  */
250 struct xilinx_cdma_desc_hw {
251 	u32 next_desc;
252 	u32 next_desc_msb;
253 	u32 src_addr;
254 	u32 src_addr_msb;
255 	u32 dest_addr;
256 	u32 dest_addr_msb;
257 	u32 control;
258 	u32 status;
259 } __aligned(64);
260 
261 /**
262  * struct xilinx_vdma_tx_segment - Descriptor segment
263  * @hw: Hardware descriptor
264  * @node: Node in the descriptor segments list
265  * @phys: Physical address of segment
266  */
267 struct xilinx_vdma_tx_segment {
268 	struct xilinx_vdma_desc_hw hw;
269 	struct list_head node;
270 	dma_addr_t phys;
271 } __aligned(64);
272 
273 /**
274  * struct xilinx_axidma_tx_segment - Descriptor segment
275  * @hw: Hardware descriptor
276  * @node: Node in the descriptor segments list
277  * @phys: Physical address of segment
278  */
279 struct xilinx_axidma_tx_segment {
280 	struct xilinx_axidma_desc_hw hw;
281 	struct list_head node;
282 	dma_addr_t phys;
283 } __aligned(64);
284 
285 /**
286  * struct xilinx_cdma_tx_segment - Descriptor segment
287  * @hw: Hardware descriptor
288  * @node: Node in the descriptor segments list
289  * @phys: Physical address of segment
290  */
291 struct xilinx_cdma_tx_segment {
292 	struct xilinx_cdma_desc_hw hw;
293 	struct list_head node;
294 	dma_addr_t phys;
295 } __aligned(64);
296 
297 /**
298  * struct xilinx_dma_tx_descriptor - Per Transaction structure
299  * @async_tx: Async transaction descriptor
300  * @segments: TX segments list
301  * @node: Node in the channel descriptors list
302  * @cyclic: Check for cyclic transfers.
303  */
304 struct xilinx_dma_tx_descriptor {
305 	struct dma_async_tx_descriptor async_tx;
306 	struct list_head segments;
307 	struct list_head node;
308 	bool cyclic;
309 };
310 
311 /**
312  * struct xilinx_dma_chan - Driver specific DMA channel structure
313  * @xdev: Driver specific device structure
314  * @ctrl_offset: Control registers offset
315  * @desc_offset: TX descriptor registers offset
316  * @lock: Descriptor operation lock
317  * @pending_list: Descriptors waiting
318  * @active_list: Descriptors ready to submit
319  * @done_list: Complete descriptors
320  * @free_seg_list: Free descriptors
321  * @common: DMA common channel
322  * @desc_pool: Descriptors pool
323  * @dev: The dma device
324  * @irq: Channel IRQ
325  * @id: Channel ID
326  * @direction: Transfer direction
327  * @num_frms: Number of frames
328  * @has_sg: Support scatter transfers
329  * @cyclic: Check for cyclic transfers.
330  * @genlock: Support genlock mode
331  * @err: Channel has errors
332  * @idle: Check for channel idle
333  * @tasklet: Cleanup work after irq
334  * @config: Device configuration info
335  * @flush_on_fsync: Flush on Frame sync
336  * @desc_pendingcount: Descriptor pending count
337  * @ext_addr: Indicates 64 bit addressing is supported by dma channel
338  * @desc_submitcount: Descriptor h/w submitted count
339  * @residue: Residue for AXI DMA
340  * @seg_v: Statically allocated segments base
341  * @seg_p: Physical allocated segments base
342  * @cyclic_seg_v: Statically allocated segment base for cyclic transfers
343  * @cyclic_seg_p: Physical allocated segments base for cyclic dma
344  * @start_transfer: Differentiate b/w DMA IP's transfer
345  * @stop_transfer: Differentiate b/w DMA IP's quiesce
346  * @tdest: TDEST value for mcdma
347  * @has_vflip: S2MM vertical flip
348  */
349 struct xilinx_dma_chan {
350 	struct xilinx_dma_device *xdev;
351 	u32 ctrl_offset;
352 	u32 desc_offset;
353 	spinlock_t lock;
354 	struct list_head pending_list;
355 	struct list_head active_list;
356 	struct list_head done_list;
357 	struct list_head free_seg_list;
358 	struct dma_chan common;
359 	struct dma_pool *desc_pool;
360 	struct device *dev;
361 	int irq;
362 	int id;
363 	enum dma_transfer_direction direction;
364 	int num_frms;
365 	bool has_sg;
366 	bool cyclic;
367 	bool genlock;
368 	bool err;
369 	bool idle;
370 	struct tasklet_struct tasklet;
371 	struct xilinx_vdma_config config;
372 	bool flush_on_fsync;
373 	u32 desc_pendingcount;
374 	bool ext_addr;
375 	u32 desc_submitcount;
376 	u32 residue;
377 	struct xilinx_axidma_tx_segment *seg_v;
378 	dma_addr_t seg_p;
379 	struct xilinx_axidma_tx_segment *cyclic_seg_v;
380 	dma_addr_t cyclic_seg_p;
381 	void (*start_transfer)(struct xilinx_dma_chan *chan);
382 	int (*stop_transfer)(struct xilinx_dma_chan *chan);
383 	u16 tdest;
384 	bool has_vflip;
385 };
386 
387 /**
388  * enum xdma_ip_type - DMA IP type.
389  *
390  * @XDMA_TYPE_AXIDMA: Axi dma ip.
391  * @XDMA_TYPE_CDMA: Axi cdma ip.
392  * @XDMA_TYPE_VDMA: Axi vdma ip.
393  *
394  */
395 enum xdma_ip_type {
396 	XDMA_TYPE_AXIDMA = 0,
397 	XDMA_TYPE_CDMA,
398 	XDMA_TYPE_VDMA,
399 };
400 
401 struct xilinx_dma_config {
402 	enum xdma_ip_type dmatype;
403 	int (*clk_init)(struct platform_device *pdev, struct clk **axi_clk,
404 			struct clk **tx_clk, struct clk **txs_clk,
405 			struct clk **rx_clk, struct clk **rxs_clk);
406 };
407 
408 /**
409  * struct xilinx_dma_device - DMA device structure
410  * @regs: I/O mapped base address
411  * @dev: Device Structure
412  * @common: DMA device structure
413  * @chan: Driver specific DMA channel
414  * @mcdma: Specifies whether Multi-Channel is present or not
415  * @flush_on_fsync: Flush on frame sync
416  * @ext_addr: Indicates 64 bit addressing is supported by dma device
417  * @pdev: Platform device structure pointer
418  * @dma_config: DMA config structure
419  * @axi_clk: DMA Axi4-lite interace clock
420  * @tx_clk: DMA mm2s clock
421  * @txs_clk: DMA mm2s stream clock
422  * @rx_clk: DMA s2mm clock
423  * @rxs_clk: DMA s2mm stream clock
424  * @nr_channels: Number of channels DMA device supports
425  * @chan_id: DMA channel identifier
426  * @max_buffer_len: Max buffer length
427  */
428 struct xilinx_dma_device {
429 	void __iomem *regs;
430 	struct device *dev;
431 	struct dma_device common;
432 	struct xilinx_dma_chan *chan[XILINX_DMA_MAX_CHANS_PER_DEVICE];
433 	bool mcdma;
434 	u32 flush_on_fsync;
435 	bool ext_addr;
436 	struct platform_device  *pdev;
437 	const struct xilinx_dma_config *dma_config;
438 	struct clk *axi_clk;
439 	struct clk *tx_clk;
440 	struct clk *txs_clk;
441 	struct clk *rx_clk;
442 	struct clk *rxs_clk;
443 	u32 nr_channels;
444 	u32 chan_id;
445 	u32 max_buffer_len;
446 };
447 
448 /* Macros */
449 #define to_xilinx_chan(chan) \
450 	container_of(chan, struct xilinx_dma_chan, common)
451 #define to_dma_tx_descriptor(tx) \
452 	container_of(tx, struct xilinx_dma_tx_descriptor, async_tx)
453 #define xilinx_dma_poll_timeout(chan, reg, val, cond, delay_us, timeout_us) \
454 	readl_poll_timeout(chan->xdev->regs + chan->ctrl_offset + reg, val, \
455 			   cond, delay_us, timeout_us)
456 
457 /* IO accessors */
458 static inline u32 dma_read(struct xilinx_dma_chan *chan, u32 reg)
459 {
460 	return ioread32(chan->xdev->regs + reg);
461 }
462 
463 static inline void dma_write(struct xilinx_dma_chan *chan, u32 reg, u32 value)
464 {
465 	iowrite32(value, chan->xdev->regs + reg);
466 }
467 
468 static inline void vdma_desc_write(struct xilinx_dma_chan *chan, u32 reg,
469 				   u32 value)
470 {
471 	dma_write(chan, chan->desc_offset + reg, value);
472 }
473 
474 static inline u32 dma_ctrl_read(struct xilinx_dma_chan *chan, u32 reg)
475 {
476 	return dma_read(chan, chan->ctrl_offset + reg);
477 }
478 
479 static inline void dma_ctrl_write(struct xilinx_dma_chan *chan, u32 reg,
480 				   u32 value)
481 {
482 	dma_write(chan, chan->ctrl_offset + reg, value);
483 }
484 
485 static inline void dma_ctrl_clr(struct xilinx_dma_chan *chan, u32 reg,
486 				 u32 clr)
487 {
488 	dma_ctrl_write(chan, reg, dma_ctrl_read(chan, reg) & ~clr);
489 }
490 
491 static inline void dma_ctrl_set(struct xilinx_dma_chan *chan, u32 reg,
492 				 u32 set)
493 {
494 	dma_ctrl_write(chan, reg, dma_ctrl_read(chan, reg) | set);
495 }
496 
497 /**
498  * vdma_desc_write_64 - 64-bit descriptor write
499  * @chan: Driver specific VDMA channel
500  * @reg: Register to write
501  * @value_lsb: lower address of the descriptor.
502  * @value_msb: upper address of the descriptor.
503  *
504  * Since vdma driver is trying to write to a register offset which is not a
505  * multiple of 64 bits(ex : 0x5c), we are writing as two separate 32 bits
506  * instead of a single 64 bit register write.
507  */
508 static inline void vdma_desc_write_64(struct xilinx_dma_chan *chan, u32 reg,
509 				      u32 value_lsb, u32 value_msb)
510 {
511 	/* Write the lsb 32 bits*/
512 	writel(value_lsb, chan->xdev->regs + chan->desc_offset + reg);
513 
514 	/* Write the msb 32 bits */
515 	writel(value_msb, chan->xdev->regs + chan->desc_offset + reg + 4);
516 }
517 
518 static inline void dma_writeq(struct xilinx_dma_chan *chan, u32 reg, u64 value)
519 {
520 	lo_hi_writeq(value, chan->xdev->regs + chan->ctrl_offset + reg);
521 }
522 
523 static inline void xilinx_write(struct xilinx_dma_chan *chan, u32 reg,
524 				dma_addr_t addr)
525 {
526 	if (chan->ext_addr)
527 		dma_writeq(chan, reg, addr);
528 	else
529 		dma_ctrl_write(chan, reg, addr);
530 }
531 
532 static inline void xilinx_axidma_buf(struct xilinx_dma_chan *chan,
533 				     struct xilinx_axidma_desc_hw *hw,
534 				     dma_addr_t buf_addr, size_t sg_used,
535 				     size_t period_len)
536 {
537 	if (chan->ext_addr) {
538 		hw->buf_addr = lower_32_bits(buf_addr + sg_used + period_len);
539 		hw->buf_addr_msb = upper_32_bits(buf_addr + sg_used +
540 						 period_len);
541 	} else {
542 		hw->buf_addr = buf_addr + sg_used + period_len;
543 	}
544 }
545 
546 /* -----------------------------------------------------------------------------
547  * Descriptors and segments alloc and free
548  */
549 
550 /**
551  * xilinx_vdma_alloc_tx_segment - Allocate transaction segment
552  * @chan: Driver specific DMA channel
553  *
554  * Return: The allocated segment on success and NULL on failure.
555  */
556 static struct xilinx_vdma_tx_segment *
557 xilinx_vdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
558 {
559 	struct xilinx_vdma_tx_segment *segment;
560 	dma_addr_t phys;
561 
562 	segment = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &phys);
563 	if (!segment)
564 		return NULL;
565 
566 	segment->phys = phys;
567 
568 	return segment;
569 }
570 
571 /**
572  * xilinx_cdma_alloc_tx_segment - Allocate transaction segment
573  * @chan: Driver specific DMA channel
574  *
575  * Return: The allocated segment on success and NULL on failure.
576  */
577 static struct xilinx_cdma_tx_segment *
578 xilinx_cdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
579 {
580 	struct xilinx_cdma_tx_segment *segment;
581 	dma_addr_t phys;
582 
583 	segment = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &phys);
584 	if (!segment)
585 		return NULL;
586 
587 	segment->phys = phys;
588 
589 	return segment;
590 }
591 
592 /**
593  * xilinx_axidma_alloc_tx_segment - Allocate transaction segment
594  * @chan: Driver specific DMA channel
595  *
596  * Return: The allocated segment on success and NULL on failure.
597  */
598 static struct xilinx_axidma_tx_segment *
599 xilinx_axidma_alloc_tx_segment(struct xilinx_dma_chan *chan)
600 {
601 	struct xilinx_axidma_tx_segment *segment = NULL;
602 	unsigned long flags;
603 
604 	spin_lock_irqsave(&chan->lock, flags);
605 	if (!list_empty(&chan->free_seg_list)) {
606 		segment = list_first_entry(&chan->free_seg_list,
607 					   struct xilinx_axidma_tx_segment,
608 					   node);
609 		list_del(&segment->node);
610 	}
611 	spin_unlock_irqrestore(&chan->lock, flags);
612 
613 	return segment;
614 }
615 
616 static void xilinx_dma_clean_hw_desc(struct xilinx_axidma_desc_hw *hw)
617 {
618 	u32 next_desc = hw->next_desc;
619 	u32 next_desc_msb = hw->next_desc_msb;
620 
621 	memset(hw, 0, sizeof(struct xilinx_axidma_desc_hw));
622 
623 	hw->next_desc = next_desc;
624 	hw->next_desc_msb = next_desc_msb;
625 }
626 
627 /**
628  * xilinx_dma_free_tx_segment - Free transaction segment
629  * @chan: Driver specific DMA channel
630  * @segment: DMA transaction segment
631  */
632 static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan,
633 				struct xilinx_axidma_tx_segment *segment)
634 {
635 	xilinx_dma_clean_hw_desc(&segment->hw);
636 
637 	list_add_tail(&segment->node, &chan->free_seg_list);
638 }
639 
640 /**
641  * xilinx_cdma_free_tx_segment - Free transaction segment
642  * @chan: Driver specific DMA channel
643  * @segment: DMA transaction segment
644  */
645 static void xilinx_cdma_free_tx_segment(struct xilinx_dma_chan *chan,
646 				struct xilinx_cdma_tx_segment *segment)
647 {
648 	dma_pool_free(chan->desc_pool, segment, segment->phys);
649 }
650 
651 /**
652  * xilinx_vdma_free_tx_segment - Free transaction segment
653  * @chan: Driver specific DMA channel
654  * @segment: DMA transaction segment
655  */
656 static void xilinx_vdma_free_tx_segment(struct xilinx_dma_chan *chan,
657 					struct xilinx_vdma_tx_segment *segment)
658 {
659 	dma_pool_free(chan->desc_pool, segment, segment->phys);
660 }
661 
662 /**
663  * xilinx_dma_tx_descriptor - Allocate transaction descriptor
664  * @chan: Driver specific DMA channel
665  *
666  * Return: The allocated descriptor on success and NULL on failure.
667  */
668 static struct xilinx_dma_tx_descriptor *
669 xilinx_dma_alloc_tx_descriptor(struct xilinx_dma_chan *chan)
670 {
671 	struct xilinx_dma_tx_descriptor *desc;
672 
673 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
674 	if (!desc)
675 		return NULL;
676 
677 	INIT_LIST_HEAD(&desc->segments);
678 
679 	return desc;
680 }
681 
682 /**
683  * xilinx_dma_free_tx_descriptor - Free transaction descriptor
684  * @chan: Driver specific DMA channel
685  * @desc: DMA transaction descriptor
686  */
687 static void
688 xilinx_dma_free_tx_descriptor(struct xilinx_dma_chan *chan,
689 			       struct xilinx_dma_tx_descriptor *desc)
690 {
691 	struct xilinx_vdma_tx_segment *segment, *next;
692 	struct xilinx_cdma_tx_segment *cdma_segment, *cdma_next;
693 	struct xilinx_axidma_tx_segment *axidma_segment, *axidma_next;
694 
695 	if (!desc)
696 		return;
697 
698 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
699 		list_for_each_entry_safe(segment, next, &desc->segments, node) {
700 			list_del(&segment->node);
701 			xilinx_vdma_free_tx_segment(chan, segment);
702 		}
703 	} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
704 		list_for_each_entry_safe(cdma_segment, cdma_next,
705 					 &desc->segments, node) {
706 			list_del(&cdma_segment->node);
707 			xilinx_cdma_free_tx_segment(chan, cdma_segment);
708 		}
709 	} else {
710 		list_for_each_entry_safe(axidma_segment, axidma_next,
711 					 &desc->segments, node) {
712 			list_del(&axidma_segment->node);
713 			xilinx_dma_free_tx_segment(chan, axidma_segment);
714 		}
715 	}
716 
717 	kfree(desc);
718 }
719 
720 /* Required functions */
721 
722 /**
723  * xilinx_dma_free_desc_list - Free descriptors list
724  * @chan: Driver specific DMA channel
725  * @list: List to parse and delete the descriptor
726  */
727 static void xilinx_dma_free_desc_list(struct xilinx_dma_chan *chan,
728 					struct list_head *list)
729 {
730 	struct xilinx_dma_tx_descriptor *desc, *next;
731 
732 	list_for_each_entry_safe(desc, next, list, node) {
733 		list_del(&desc->node);
734 		xilinx_dma_free_tx_descriptor(chan, desc);
735 	}
736 }
737 
738 /**
739  * xilinx_dma_free_descriptors - Free channel descriptors
740  * @chan: Driver specific DMA channel
741  */
742 static void xilinx_dma_free_descriptors(struct xilinx_dma_chan *chan)
743 {
744 	unsigned long flags;
745 
746 	spin_lock_irqsave(&chan->lock, flags);
747 
748 	xilinx_dma_free_desc_list(chan, &chan->pending_list);
749 	xilinx_dma_free_desc_list(chan, &chan->done_list);
750 	xilinx_dma_free_desc_list(chan, &chan->active_list);
751 
752 	spin_unlock_irqrestore(&chan->lock, flags);
753 }
754 
755 /**
756  * xilinx_dma_free_chan_resources - Free channel resources
757  * @dchan: DMA channel
758  */
759 static void xilinx_dma_free_chan_resources(struct dma_chan *dchan)
760 {
761 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
762 	unsigned long flags;
763 
764 	dev_dbg(chan->dev, "Free all channel resources.\n");
765 
766 	xilinx_dma_free_descriptors(chan);
767 
768 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
769 		spin_lock_irqsave(&chan->lock, flags);
770 		INIT_LIST_HEAD(&chan->free_seg_list);
771 		spin_unlock_irqrestore(&chan->lock, flags);
772 
773 		/* Free memory that is allocated for BD */
774 		dma_free_coherent(chan->dev, sizeof(*chan->seg_v) *
775 				  XILINX_DMA_NUM_DESCS, chan->seg_v,
776 				  chan->seg_p);
777 
778 		/* Free Memory that is allocated for cyclic DMA Mode */
779 		dma_free_coherent(chan->dev, sizeof(*chan->cyclic_seg_v),
780 				  chan->cyclic_seg_v, chan->cyclic_seg_p);
781 	}
782 
783 	if (chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA) {
784 		dma_pool_destroy(chan->desc_pool);
785 		chan->desc_pool = NULL;
786 	}
787 }
788 
789 /**
790  * xilinx_dma_chan_handle_cyclic - Cyclic dma callback
791  * @chan: Driver specific dma channel
792  * @desc: dma transaction descriptor
793  * @flags: flags for spin lock
794  */
795 static void xilinx_dma_chan_handle_cyclic(struct xilinx_dma_chan *chan,
796 					  struct xilinx_dma_tx_descriptor *desc,
797 					  unsigned long *flags)
798 {
799 	dma_async_tx_callback callback;
800 	void *callback_param;
801 
802 	callback = desc->async_tx.callback;
803 	callback_param = desc->async_tx.callback_param;
804 	if (callback) {
805 		spin_unlock_irqrestore(&chan->lock, *flags);
806 		callback(callback_param);
807 		spin_lock_irqsave(&chan->lock, *flags);
808 	}
809 }
810 
811 /**
812  * xilinx_dma_chan_desc_cleanup - Clean channel descriptors
813  * @chan: Driver specific DMA channel
814  */
815 static void xilinx_dma_chan_desc_cleanup(struct xilinx_dma_chan *chan)
816 {
817 	struct xilinx_dma_tx_descriptor *desc, *next;
818 	unsigned long flags;
819 
820 	spin_lock_irqsave(&chan->lock, flags);
821 
822 	list_for_each_entry_safe(desc, next, &chan->done_list, node) {
823 		struct dmaengine_desc_callback cb;
824 
825 		if (desc->cyclic) {
826 			xilinx_dma_chan_handle_cyclic(chan, desc, &flags);
827 			break;
828 		}
829 
830 		/* Remove from the list of running transactions */
831 		list_del(&desc->node);
832 
833 		/* Run the link descriptor callback function */
834 		dmaengine_desc_get_callback(&desc->async_tx, &cb);
835 		if (dmaengine_desc_callback_valid(&cb)) {
836 			spin_unlock_irqrestore(&chan->lock, flags);
837 			dmaengine_desc_callback_invoke(&cb, NULL);
838 			spin_lock_irqsave(&chan->lock, flags);
839 		}
840 
841 		/* Run any dependencies, then free the descriptor */
842 		dma_run_dependencies(&desc->async_tx);
843 		xilinx_dma_free_tx_descriptor(chan, desc);
844 	}
845 
846 	spin_unlock_irqrestore(&chan->lock, flags);
847 }
848 
849 /**
850  * xilinx_dma_do_tasklet - Schedule completion tasklet
851  * @data: Pointer to the Xilinx DMA channel structure
852  */
853 static void xilinx_dma_do_tasklet(unsigned long data)
854 {
855 	struct xilinx_dma_chan *chan = (struct xilinx_dma_chan *)data;
856 
857 	xilinx_dma_chan_desc_cleanup(chan);
858 }
859 
860 /**
861  * xilinx_dma_alloc_chan_resources - Allocate channel resources
862  * @dchan: DMA channel
863  *
864  * Return: '0' on success and failure value on error
865  */
866 static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
867 {
868 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
869 	int i;
870 
871 	/* Has this channel already been allocated? */
872 	if (chan->desc_pool)
873 		return 0;
874 
875 	/*
876 	 * We need the descriptor to be aligned to 64bytes
877 	 * for meeting Xilinx VDMA specification requirement.
878 	 */
879 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
880 		/* Allocate the buffer descriptors. */
881 		chan->seg_v = dma_alloc_coherent(chan->dev,
882 						 sizeof(*chan->seg_v) * XILINX_DMA_NUM_DESCS,
883 						 &chan->seg_p, GFP_KERNEL);
884 		if (!chan->seg_v) {
885 			dev_err(chan->dev,
886 				"unable to allocate channel %d descriptors\n",
887 				chan->id);
888 			return -ENOMEM;
889 		}
890 		/*
891 		 * For cyclic DMA mode we need to program the tail Descriptor
892 		 * register with a value which is not a part of the BD chain
893 		 * so allocating a desc segment during channel allocation for
894 		 * programming tail descriptor.
895 		 */
896 		chan->cyclic_seg_v = dma_alloc_coherent(chan->dev,
897 							sizeof(*chan->cyclic_seg_v),
898 							&chan->cyclic_seg_p,
899 							GFP_KERNEL);
900 		if (!chan->cyclic_seg_v) {
901 			dev_err(chan->dev,
902 				"unable to allocate desc segment for cyclic DMA\n");
903 			dma_free_coherent(chan->dev, sizeof(*chan->seg_v) *
904 				XILINX_DMA_NUM_DESCS, chan->seg_v,
905 				chan->seg_p);
906 			return -ENOMEM;
907 		}
908 		chan->cyclic_seg_v->phys = chan->cyclic_seg_p;
909 
910 		for (i = 0; i < XILINX_DMA_NUM_DESCS; i++) {
911 			chan->seg_v[i].hw.next_desc =
912 			lower_32_bits(chan->seg_p + sizeof(*chan->seg_v) *
913 				((i + 1) % XILINX_DMA_NUM_DESCS));
914 			chan->seg_v[i].hw.next_desc_msb =
915 			upper_32_bits(chan->seg_p + sizeof(*chan->seg_v) *
916 				((i + 1) % XILINX_DMA_NUM_DESCS));
917 			chan->seg_v[i].phys = chan->seg_p +
918 				sizeof(*chan->seg_v) * i;
919 			list_add_tail(&chan->seg_v[i].node,
920 				      &chan->free_seg_list);
921 		}
922 	} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
923 		chan->desc_pool = dma_pool_create("xilinx_cdma_desc_pool",
924 				   chan->dev,
925 				   sizeof(struct xilinx_cdma_tx_segment),
926 				   __alignof__(struct xilinx_cdma_tx_segment),
927 				   0);
928 	} else {
929 		chan->desc_pool = dma_pool_create("xilinx_vdma_desc_pool",
930 				     chan->dev,
931 				     sizeof(struct xilinx_vdma_tx_segment),
932 				     __alignof__(struct xilinx_vdma_tx_segment),
933 				     0);
934 	}
935 
936 	if (!chan->desc_pool &&
937 	    (chan->xdev->dma_config->dmatype != XDMA_TYPE_AXIDMA)) {
938 		dev_err(chan->dev,
939 			"unable to allocate channel %d descriptor pool\n",
940 			chan->id);
941 		return -ENOMEM;
942 	}
943 
944 	dma_cookie_init(dchan);
945 
946 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
947 		/* For AXI DMA resetting once channel will reset the
948 		 * other channel as well so enable the interrupts here.
949 		 */
950 		dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
951 			      XILINX_DMA_DMAXR_ALL_IRQ_MASK);
952 	}
953 
954 	if ((chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) && chan->has_sg)
955 		dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
956 			     XILINX_CDMA_CR_SGMODE);
957 
958 	return 0;
959 }
960 
961 /**
962  * xilinx_dma_calc_copysize - Calculate the amount of data to copy
963  * @chan: Driver specific DMA channel
964  * @size: Total data that needs to be copied
965  * @done: Amount of data that has been already copied
966  *
967  * Return: Amount of data that has to be copied
968  */
969 static int xilinx_dma_calc_copysize(struct xilinx_dma_chan *chan,
970 				    int size, int done)
971 {
972 	size_t copy;
973 
974 	copy = min_t(size_t, size - done,
975 		     chan->xdev->max_buffer_len);
976 
977 	if ((copy + done < size) &&
978 	    chan->xdev->common.copy_align) {
979 		/*
980 		 * If this is not the last descriptor, make sure
981 		 * the next one will be properly aligned
982 		 */
983 		copy = rounddown(copy,
984 				 (1 << chan->xdev->common.copy_align));
985 	}
986 	return copy;
987 }
988 
989 /**
990  * xilinx_dma_tx_status - Get DMA transaction status
991  * @dchan: DMA channel
992  * @cookie: Transaction identifier
993  * @txstate: Transaction state
994  *
995  * Return: DMA transaction status
996  */
997 static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan,
998 					dma_cookie_t cookie,
999 					struct dma_tx_state *txstate)
1000 {
1001 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1002 	struct xilinx_dma_tx_descriptor *desc;
1003 	struct xilinx_axidma_tx_segment *segment;
1004 	struct xilinx_axidma_desc_hw *hw;
1005 	enum dma_status ret;
1006 	unsigned long flags;
1007 	u32 residue = 0;
1008 
1009 	ret = dma_cookie_status(dchan, cookie, txstate);
1010 	if (ret == DMA_COMPLETE || !txstate)
1011 		return ret;
1012 
1013 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
1014 		spin_lock_irqsave(&chan->lock, flags);
1015 
1016 		desc = list_last_entry(&chan->active_list,
1017 				       struct xilinx_dma_tx_descriptor, node);
1018 		if (chan->has_sg) {
1019 			list_for_each_entry(segment, &desc->segments, node) {
1020 				hw = &segment->hw;
1021 				residue += (hw->control - hw->status) &
1022 					   chan->xdev->max_buffer_len;
1023 			}
1024 		}
1025 		spin_unlock_irqrestore(&chan->lock, flags);
1026 
1027 		chan->residue = residue;
1028 		dma_set_residue(txstate, chan->residue);
1029 	}
1030 
1031 	return ret;
1032 }
1033 
1034 /**
1035  * xilinx_dma_stop_transfer - Halt DMA channel
1036  * @chan: Driver specific DMA channel
1037  *
1038  * Return: '0' on success and failure value on error
1039  */
1040 static int xilinx_dma_stop_transfer(struct xilinx_dma_chan *chan)
1041 {
1042 	u32 val;
1043 
1044 	dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR, XILINX_DMA_DMACR_RUNSTOP);
1045 
1046 	/* Wait for the hardware to halt */
1047 	return xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMASR, val,
1048 				       val & XILINX_DMA_DMASR_HALTED, 0,
1049 				       XILINX_DMA_LOOP_COUNT);
1050 }
1051 
1052 /**
1053  * xilinx_cdma_stop_transfer - Wait for the current transfer to complete
1054  * @chan: Driver specific DMA channel
1055  *
1056  * Return: '0' on success and failure value on error
1057  */
1058 static int xilinx_cdma_stop_transfer(struct xilinx_dma_chan *chan)
1059 {
1060 	u32 val;
1061 
1062 	return xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMASR, val,
1063 				       val & XILINX_DMA_DMASR_IDLE, 0,
1064 				       XILINX_DMA_LOOP_COUNT);
1065 }
1066 
1067 /**
1068  * xilinx_dma_start - Start DMA channel
1069  * @chan: Driver specific DMA channel
1070  */
1071 static void xilinx_dma_start(struct xilinx_dma_chan *chan)
1072 {
1073 	int err;
1074 	u32 val;
1075 
1076 	dma_ctrl_set(chan, XILINX_DMA_REG_DMACR, XILINX_DMA_DMACR_RUNSTOP);
1077 
1078 	/* Wait for the hardware to start */
1079 	err = xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMASR, val,
1080 				      !(val & XILINX_DMA_DMASR_HALTED), 0,
1081 				      XILINX_DMA_LOOP_COUNT);
1082 
1083 	if (err) {
1084 		dev_err(chan->dev, "Cannot start channel %p: %x\n",
1085 			chan, dma_ctrl_read(chan, XILINX_DMA_REG_DMASR));
1086 
1087 		chan->err = true;
1088 	}
1089 }
1090 
1091 /**
1092  * xilinx_vdma_start_transfer - Starts VDMA transfer
1093  * @chan: Driver specific channel struct pointer
1094  */
1095 static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
1096 {
1097 	struct xilinx_vdma_config *config = &chan->config;
1098 	struct xilinx_dma_tx_descriptor *desc;
1099 	u32 reg, j;
1100 	struct xilinx_vdma_tx_segment *segment, *last = NULL;
1101 	int i = 0;
1102 
1103 	/* This function was invoked with lock held */
1104 	if (chan->err)
1105 		return;
1106 
1107 	if (!chan->idle)
1108 		return;
1109 
1110 	if (list_empty(&chan->pending_list))
1111 		return;
1112 
1113 	desc = list_first_entry(&chan->pending_list,
1114 				struct xilinx_dma_tx_descriptor, node);
1115 
1116 	/* Configure the hardware using info in the config structure */
1117 	if (chan->has_vflip) {
1118 		reg = dma_read(chan, XILINX_VDMA_REG_ENABLE_VERTICAL_FLIP);
1119 		reg &= ~XILINX_VDMA_ENABLE_VERTICAL_FLIP;
1120 		reg |= config->vflip_en;
1121 		dma_write(chan, XILINX_VDMA_REG_ENABLE_VERTICAL_FLIP,
1122 			  reg);
1123 	}
1124 
1125 	reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
1126 
1127 	if (config->frm_cnt_en)
1128 		reg |= XILINX_DMA_DMACR_FRAMECNT_EN;
1129 	else
1130 		reg &= ~XILINX_DMA_DMACR_FRAMECNT_EN;
1131 
1132 	/* If not parking, enable circular mode */
1133 	if (config->park)
1134 		reg &= ~XILINX_DMA_DMACR_CIRC_EN;
1135 	else
1136 		reg |= XILINX_DMA_DMACR_CIRC_EN;
1137 
1138 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
1139 
1140 	j = chan->desc_submitcount;
1141 	reg = dma_read(chan, XILINX_DMA_REG_PARK_PTR);
1142 	if (chan->direction == DMA_MEM_TO_DEV) {
1143 		reg &= ~XILINX_DMA_PARK_PTR_RD_REF_MASK;
1144 		reg |= j << XILINX_DMA_PARK_PTR_RD_REF_SHIFT;
1145 	} else {
1146 		reg &= ~XILINX_DMA_PARK_PTR_WR_REF_MASK;
1147 		reg |= j << XILINX_DMA_PARK_PTR_WR_REF_SHIFT;
1148 	}
1149 	dma_write(chan, XILINX_DMA_REG_PARK_PTR, reg);
1150 
1151 	/* Start the hardware */
1152 	xilinx_dma_start(chan);
1153 
1154 	if (chan->err)
1155 		return;
1156 
1157 	/* Start the transfer */
1158 	if (chan->desc_submitcount < chan->num_frms)
1159 		i = chan->desc_submitcount;
1160 
1161 	list_for_each_entry(segment, &desc->segments, node) {
1162 		if (chan->ext_addr)
1163 			vdma_desc_write_64(chan,
1164 				   XILINX_VDMA_REG_START_ADDRESS_64(i++),
1165 				   segment->hw.buf_addr,
1166 				   segment->hw.buf_addr_msb);
1167 		else
1168 			vdma_desc_write(chan,
1169 					XILINX_VDMA_REG_START_ADDRESS(i++),
1170 					segment->hw.buf_addr);
1171 
1172 		last = segment;
1173 	}
1174 
1175 	if (!last)
1176 		return;
1177 
1178 	/* HW expects these parameters to be same for one transaction */
1179 	vdma_desc_write(chan, XILINX_DMA_REG_HSIZE, last->hw.hsize);
1180 	vdma_desc_write(chan, XILINX_DMA_REG_FRMDLY_STRIDE,
1181 			last->hw.stride);
1182 	vdma_desc_write(chan, XILINX_DMA_REG_VSIZE, last->hw.vsize);
1183 
1184 	chan->desc_submitcount++;
1185 	chan->desc_pendingcount--;
1186 	list_del(&desc->node);
1187 	list_add_tail(&desc->node, &chan->active_list);
1188 	if (chan->desc_submitcount == chan->num_frms)
1189 		chan->desc_submitcount = 0;
1190 
1191 	chan->idle = false;
1192 }
1193 
1194 /**
1195  * xilinx_cdma_start_transfer - Starts cdma transfer
1196  * @chan: Driver specific channel struct pointer
1197  */
1198 static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
1199 {
1200 	struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
1201 	struct xilinx_cdma_tx_segment *tail_segment;
1202 	u32 ctrl_reg = dma_read(chan, XILINX_DMA_REG_DMACR);
1203 
1204 	if (chan->err)
1205 		return;
1206 
1207 	if (!chan->idle)
1208 		return;
1209 
1210 	if (list_empty(&chan->pending_list))
1211 		return;
1212 
1213 	head_desc = list_first_entry(&chan->pending_list,
1214 				     struct xilinx_dma_tx_descriptor, node);
1215 	tail_desc = list_last_entry(&chan->pending_list,
1216 				    struct xilinx_dma_tx_descriptor, node);
1217 	tail_segment = list_last_entry(&tail_desc->segments,
1218 				       struct xilinx_cdma_tx_segment, node);
1219 
1220 	if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
1221 		ctrl_reg &= ~XILINX_DMA_CR_COALESCE_MAX;
1222 		ctrl_reg |= chan->desc_pendingcount <<
1223 				XILINX_DMA_CR_COALESCE_SHIFT;
1224 		dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, ctrl_reg);
1225 	}
1226 
1227 	if (chan->has_sg) {
1228 		dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR,
1229 			     XILINX_CDMA_CR_SGMODE);
1230 
1231 		dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
1232 			     XILINX_CDMA_CR_SGMODE);
1233 
1234 		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
1235 			     head_desc->async_tx.phys);
1236 
1237 		/* Update tail ptr register which will start the transfer */
1238 		xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
1239 			     tail_segment->phys);
1240 	} else {
1241 		/* In simple mode */
1242 		struct xilinx_cdma_tx_segment *segment;
1243 		struct xilinx_cdma_desc_hw *hw;
1244 
1245 		segment = list_first_entry(&head_desc->segments,
1246 					   struct xilinx_cdma_tx_segment,
1247 					   node);
1248 
1249 		hw = &segment->hw;
1250 
1251 		xilinx_write(chan, XILINX_CDMA_REG_SRCADDR,
1252 			     xilinx_prep_dma_addr_t(hw->src_addr));
1253 		xilinx_write(chan, XILINX_CDMA_REG_DSTADDR,
1254 			     xilinx_prep_dma_addr_t(hw->dest_addr));
1255 
1256 		/* Start the transfer */
1257 		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
1258 				hw->control & chan->xdev->max_buffer_len);
1259 	}
1260 
1261 	list_splice_tail_init(&chan->pending_list, &chan->active_list);
1262 	chan->desc_pendingcount = 0;
1263 	chan->idle = false;
1264 }
1265 
1266 /**
1267  * xilinx_dma_start_transfer - Starts DMA transfer
1268  * @chan: Driver specific channel struct pointer
1269  */
1270 static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
1271 {
1272 	struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
1273 	struct xilinx_axidma_tx_segment *tail_segment;
1274 	u32 reg;
1275 
1276 	if (chan->err)
1277 		return;
1278 
1279 	if (list_empty(&chan->pending_list))
1280 		return;
1281 
1282 	if (!chan->idle)
1283 		return;
1284 
1285 	head_desc = list_first_entry(&chan->pending_list,
1286 				     struct xilinx_dma_tx_descriptor, node);
1287 	tail_desc = list_last_entry(&chan->pending_list,
1288 				    struct xilinx_dma_tx_descriptor, node);
1289 	tail_segment = list_last_entry(&tail_desc->segments,
1290 				       struct xilinx_axidma_tx_segment, node);
1291 
1292 	reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
1293 
1294 	if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
1295 		reg &= ~XILINX_DMA_CR_COALESCE_MAX;
1296 		reg |= chan->desc_pendingcount <<
1297 				  XILINX_DMA_CR_COALESCE_SHIFT;
1298 		dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
1299 	}
1300 
1301 	if (chan->has_sg && !chan->xdev->mcdma)
1302 		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
1303 			     head_desc->async_tx.phys);
1304 
1305 	if (chan->has_sg && chan->xdev->mcdma) {
1306 		if (chan->direction == DMA_MEM_TO_DEV) {
1307 			dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
1308 				       head_desc->async_tx.phys);
1309 		} else {
1310 			if (!chan->tdest) {
1311 				dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
1312 				       head_desc->async_tx.phys);
1313 			} else {
1314 				dma_ctrl_write(chan,
1315 					XILINX_DMA_MCRX_CDESC(chan->tdest),
1316 				       head_desc->async_tx.phys);
1317 			}
1318 		}
1319 	}
1320 
1321 	xilinx_dma_start(chan);
1322 
1323 	if (chan->err)
1324 		return;
1325 
1326 	/* Start the transfer */
1327 	if (chan->has_sg && !chan->xdev->mcdma) {
1328 		if (chan->cyclic)
1329 			xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
1330 				     chan->cyclic_seg_v->phys);
1331 		else
1332 			xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
1333 				     tail_segment->phys);
1334 	} else if (chan->has_sg && chan->xdev->mcdma) {
1335 		if (chan->direction == DMA_MEM_TO_DEV) {
1336 			dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
1337 			       tail_segment->phys);
1338 		} else {
1339 			if (!chan->tdest) {
1340 				dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
1341 					       tail_segment->phys);
1342 			} else {
1343 				dma_ctrl_write(chan,
1344 					XILINX_DMA_MCRX_TDESC(chan->tdest),
1345 					tail_segment->phys);
1346 			}
1347 		}
1348 	} else {
1349 		struct xilinx_axidma_tx_segment *segment;
1350 		struct xilinx_axidma_desc_hw *hw;
1351 
1352 		segment = list_first_entry(&head_desc->segments,
1353 					   struct xilinx_axidma_tx_segment,
1354 					   node);
1355 		hw = &segment->hw;
1356 
1357 		xilinx_write(chan, XILINX_DMA_REG_SRCDSTADDR, hw->buf_addr);
1358 
1359 		/* Start the transfer */
1360 		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
1361 			       hw->control & chan->xdev->max_buffer_len);
1362 	}
1363 
1364 	list_splice_tail_init(&chan->pending_list, &chan->active_list);
1365 	chan->desc_pendingcount = 0;
1366 	chan->idle = false;
1367 }
1368 
1369 /**
1370  * xilinx_dma_issue_pending - Issue pending transactions
1371  * @dchan: DMA channel
1372  */
1373 static void xilinx_dma_issue_pending(struct dma_chan *dchan)
1374 {
1375 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1376 	unsigned long flags;
1377 
1378 	spin_lock_irqsave(&chan->lock, flags);
1379 	chan->start_transfer(chan);
1380 	spin_unlock_irqrestore(&chan->lock, flags);
1381 }
1382 
1383 /**
1384  * xilinx_dma_complete_descriptor - Mark the active descriptor as complete
1385  * @chan : xilinx DMA channel
1386  *
1387  * CONTEXT: hardirq
1388  */
1389 static void xilinx_dma_complete_descriptor(struct xilinx_dma_chan *chan)
1390 {
1391 	struct xilinx_dma_tx_descriptor *desc, *next;
1392 
1393 	/* This function was invoked with lock held */
1394 	if (list_empty(&chan->active_list))
1395 		return;
1396 
1397 	list_for_each_entry_safe(desc, next, &chan->active_list, node) {
1398 		list_del(&desc->node);
1399 		if (!desc->cyclic)
1400 			dma_cookie_complete(&desc->async_tx);
1401 		list_add_tail(&desc->node, &chan->done_list);
1402 	}
1403 }
1404 
1405 /**
1406  * xilinx_dma_reset - Reset DMA channel
1407  * @chan: Driver specific DMA channel
1408  *
1409  * Return: '0' on success and failure value on error
1410  */
1411 static int xilinx_dma_reset(struct xilinx_dma_chan *chan)
1412 {
1413 	int err;
1414 	u32 tmp;
1415 
1416 	dma_ctrl_set(chan, XILINX_DMA_REG_DMACR, XILINX_DMA_DMACR_RESET);
1417 
1418 	/* Wait for the hardware to finish reset */
1419 	err = xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMACR, tmp,
1420 				      !(tmp & XILINX_DMA_DMACR_RESET), 0,
1421 				      XILINX_DMA_LOOP_COUNT);
1422 
1423 	if (err) {
1424 		dev_err(chan->dev, "reset timeout, cr %x, sr %x\n",
1425 			dma_ctrl_read(chan, XILINX_DMA_REG_DMACR),
1426 			dma_ctrl_read(chan, XILINX_DMA_REG_DMASR));
1427 		return -ETIMEDOUT;
1428 	}
1429 
1430 	chan->err = false;
1431 	chan->idle = true;
1432 	chan->desc_submitcount = 0;
1433 
1434 	return err;
1435 }
1436 
1437 /**
1438  * xilinx_dma_chan_reset - Reset DMA channel and enable interrupts
1439  * @chan: Driver specific DMA channel
1440  *
1441  * Return: '0' on success and failure value on error
1442  */
1443 static int xilinx_dma_chan_reset(struct xilinx_dma_chan *chan)
1444 {
1445 	int err;
1446 
1447 	/* Reset VDMA */
1448 	err = xilinx_dma_reset(chan);
1449 	if (err)
1450 		return err;
1451 
1452 	/* Enable interrupts */
1453 	dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
1454 		      XILINX_DMA_DMAXR_ALL_IRQ_MASK);
1455 
1456 	return 0;
1457 }
1458 
1459 /**
1460  * xilinx_dma_irq_handler - DMA Interrupt handler
1461  * @irq: IRQ number
1462  * @data: Pointer to the Xilinx DMA channel structure
1463  *
1464  * Return: IRQ_HANDLED/IRQ_NONE
1465  */
1466 static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
1467 {
1468 	struct xilinx_dma_chan *chan = data;
1469 	u32 status;
1470 
1471 	/* Read the status and ack the interrupts. */
1472 	status = dma_ctrl_read(chan, XILINX_DMA_REG_DMASR);
1473 	if (!(status & XILINX_DMA_DMAXR_ALL_IRQ_MASK))
1474 		return IRQ_NONE;
1475 
1476 	dma_ctrl_write(chan, XILINX_DMA_REG_DMASR,
1477 			status & XILINX_DMA_DMAXR_ALL_IRQ_MASK);
1478 
1479 	if (status & XILINX_DMA_DMASR_ERR_IRQ) {
1480 		/*
1481 		 * An error occurred. If C_FLUSH_ON_FSYNC is enabled and the
1482 		 * error is recoverable, ignore it. Otherwise flag the error.
1483 		 *
1484 		 * Only recoverable errors can be cleared in the DMASR register,
1485 		 * make sure not to write to other error bits to 1.
1486 		 */
1487 		u32 errors = status & XILINX_DMA_DMASR_ALL_ERR_MASK;
1488 
1489 		dma_ctrl_write(chan, XILINX_DMA_REG_DMASR,
1490 				errors & XILINX_DMA_DMASR_ERR_RECOVER_MASK);
1491 
1492 		if (!chan->flush_on_fsync ||
1493 		    (errors & ~XILINX_DMA_DMASR_ERR_RECOVER_MASK)) {
1494 			dev_err(chan->dev,
1495 				"Channel %p has errors %x, cdr %x tdr %x\n",
1496 				chan, errors,
1497 				dma_ctrl_read(chan, XILINX_DMA_REG_CURDESC),
1498 				dma_ctrl_read(chan, XILINX_DMA_REG_TAILDESC));
1499 			chan->err = true;
1500 		}
1501 	}
1502 
1503 	if (status & XILINX_DMA_DMASR_DLY_CNT_IRQ) {
1504 		/*
1505 		 * Device takes too long to do the transfer when user requires
1506 		 * responsiveness.
1507 		 */
1508 		dev_dbg(chan->dev, "Inter-packet latency too long\n");
1509 	}
1510 
1511 	if (status & XILINX_DMA_DMASR_FRM_CNT_IRQ) {
1512 		spin_lock(&chan->lock);
1513 		xilinx_dma_complete_descriptor(chan);
1514 		chan->idle = true;
1515 		chan->start_transfer(chan);
1516 		spin_unlock(&chan->lock);
1517 	}
1518 
1519 	tasklet_schedule(&chan->tasklet);
1520 	return IRQ_HANDLED;
1521 }
1522 
1523 /**
1524  * append_desc_queue - Queuing descriptor
1525  * @chan: Driver specific dma channel
1526  * @desc: dma transaction descriptor
1527  */
1528 static void append_desc_queue(struct xilinx_dma_chan *chan,
1529 			      struct xilinx_dma_tx_descriptor *desc)
1530 {
1531 	struct xilinx_vdma_tx_segment *tail_segment;
1532 	struct xilinx_dma_tx_descriptor *tail_desc;
1533 	struct xilinx_axidma_tx_segment *axidma_tail_segment;
1534 	struct xilinx_cdma_tx_segment *cdma_tail_segment;
1535 
1536 	if (list_empty(&chan->pending_list))
1537 		goto append;
1538 
1539 	/*
1540 	 * Add the hardware descriptor to the chain of hardware descriptors
1541 	 * that already exists in memory.
1542 	 */
1543 	tail_desc = list_last_entry(&chan->pending_list,
1544 				    struct xilinx_dma_tx_descriptor, node);
1545 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
1546 		tail_segment = list_last_entry(&tail_desc->segments,
1547 					       struct xilinx_vdma_tx_segment,
1548 					       node);
1549 		tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
1550 	} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
1551 		cdma_tail_segment = list_last_entry(&tail_desc->segments,
1552 						struct xilinx_cdma_tx_segment,
1553 						node);
1554 		cdma_tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
1555 	} else {
1556 		axidma_tail_segment = list_last_entry(&tail_desc->segments,
1557 					       struct xilinx_axidma_tx_segment,
1558 					       node);
1559 		axidma_tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
1560 	}
1561 
1562 	/*
1563 	 * Add the software descriptor and all children to the list
1564 	 * of pending transactions
1565 	 */
1566 append:
1567 	list_add_tail(&desc->node, &chan->pending_list);
1568 	chan->desc_pendingcount++;
1569 
1570 	if (chan->has_sg && (chan->xdev->dma_config->dmatype == XDMA_TYPE_VDMA)
1571 	    && unlikely(chan->desc_pendingcount > chan->num_frms)) {
1572 		dev_dbg(chan->dev, "desc pendingcount is too high\n");
1573 		chan->desc_pendingcount = chan->num_frms;
1574 	}
1575 }
1576 
1577 /**
1578  * xilinx_dma_tx_submit - Submit DMA transaction
1579  * @tx: Async transaction descriptor
1580  *
1581  * Return: cookie value on success and failure value on error
1582  */
1583 static dma_cookie_t xilinx_dma_tx_submit(struct dma_async_tx_descriptor *tx)
1584 {
1585 	struct xilinx_dma_tx_descriptor *desc = to_dma_tx_descriptor(tx);
1586 	struct xilinx_dma_chan *chan = to_xilinx_chan(tx->chan);
1587 	dma_cookie_t cookie;
1588 	unsigned long flags;
1589 	int err;
1590 
1591 	if (chan->cyclic) {
1592 		xilinx_dma_free_tx_descriptor(chan, desc);
1593 		return -EBUSY;
1594 	}
1595 
1596 	if (chan->err) {
1597 		/*
1598 		 * If reset fails, need to hard reset the system.
1599 		 * Channel is no longer functional
1600 		 */
1601 		err = xilinx_dma_chan_reset(chan);
1602 		if (err < 0)
1603 			return err;
1604 	}
1605 
1606 	spin_lock_irqsave(&chan->lock, flags);
1607 
1608 	cookie = dma_cookie_assign(tx);
1609 
1610 	/* Put this transaction onto the tail of the pending queue */
1611 	append_desc_queue(chan, desc);
1612 
1613 	if (desc->cyclic)
1614 		chan->cyclic = true;
1615 
1616 	spin_unlock_irqrestore(&chan->lock, flags);
1617 
1618 	return cookie;
1619 }
1620 
1621 /**
1622  * xilinx_vdma_dma_prep_interleaved - prepare a descriptor for a
1623  *	DMA_SLAVE transaction
1624  * @dchan: DMA channel
1625  * @xt: Interleaved template pointer
1626  * @flags: transfer ack flags
1627  *
1628  * Return: Async transaction descriptor on success and NULL on failure
1629  */
1630 static struct dma_async_tx_descriptor *
1631 xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
1632 				 struct dma_interleaved_template *xt,
1633 				 unsigned long flags)
1634 {
1635 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1636 	struct xilinx_dma_tx_descriptor *desc;
1637 	struct xilinx_vdma_tx_segment *segment;
1638 	struct xilinx_vdma_desc_hw *hw;
1639 
1640 	if (!is_slave_direction(xt->dir))
1641 		return NULL;
1642 
1643 	if (!xt->numf || !xt->sgl[0].size)
1644 		return NULL;
1645 
1646 	if (xt->frame_size != 1)
1647 		return NULL;
1648 
1649 	/* Allocate a transaction descriptor. */
1650 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1651 	if (!desc)
1652 		return NULL;
1653 
1654 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1655 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1656 	async_tx_ack(&desc->async_tx);
1657 
1658 	/* Allocate the link descriptor from DMA pool */
1659 	segment = xilinx_vdma_alloc_tx_segment(chan);
1660 	if (!segment)
1661 		goto error;
1662 
1663 	/* Fill in the hardware descriptor */
1664 	hw = &segment->hw;
1665 	hw->vsize = xt->numf;
1666 	hw->hsize = xt->sgl[0].size;
1667 	hw->stride = (xt->sgl[0].icg + xt->sgl[0].size) <<
1668 			XILINX_DMA_FRMDLY_STRIDE_STRIDE_SHIFT;
1669 	hw->stride |= chan->config.frm_dly <<
1670 			XILINX_DMA_FRMDLY_STRIDE_FRMDLY_SHIFT;
1671 
1672 	if (xt->dir != DMA_MEM_TO_DEV) {
1673 		if (chan->ext_addr) {
1674 			hw->buf_addr = lower_32_bits(xt->dst_start);
1675 			hw->buf_addr_msb = upper_32_bits(xt->dst_start);
1676 		} else {
1677 			hw->buf_addr = xt->dst_start;
1678 		}
1679 	} else {
1680 		if (chan->ext_addr) {
1681 			hw->buf_addr = lower_32_bits(xt->src_start);
1682 			hw->buf_addr_msb = upper_32_bits(xt->src_start);
1683 		} else {
1684 			hw->buf_addr = xt->src_start;
1685 		}
1686 	}
1687 
1688 	/* Insert the segment into the descriptor segments list. */
1689 	list_add_tail(&segment->node, &desc->segments);
1690 
1691 	/* Link the last hardware descriptor with the first. */
1692 	segment = list_first_entry(&desc->segments,
1693 				   struct xilinx_vdma_tx_segment, node);
1694 	desc->async_tx.phys = segment->phys;
1695 
1696 	return &desc->async_tx;
1697 
1698 error:
1699 	xilinx_dma_free_tx_descriptor(chan, desc);
1700 	return NULL;
1701 }
1702 
1703 /**
1704  * xilinx_cdma_prep_memcpy - prepare descriptors for a memcpy transaction
1705  * @dchan: DMA channel
1706  * @dma_dst: destination address
1707  * @dma_src: source address
1708  * @len: transfer length
1709  * @flags: transfer ack flags
1710  *
1711  * Return: Async transaction descriptor on success and NULL on failure
1712  */
1713 static struct dma_async_tx_descriptor *
1714 xilinx_cdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
1715 			dma_addr_t dma_src, size_t len, unsigned long flags)
1716 {
1717 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1718 	struct xilinx_dma_tx_descriptor *desc;
1719 	struct xilinx_cdma_tx_segment *segment;
1720 	struct xilinx_cdma_desc_hw *hw;
1721 
1722 	if (!len || len > chan->xdev->max_buffer_len)
1723 		return NULL;
1724 
1725 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1726 	if (!desc)
1727 		return NULL;
1728 
1729 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1730 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1731 
1732 	/* Allocate the link descriptor from DMA pool */
1733 	segment = xilinx_cdma_alloc_tx_segment(chan);
1734 	if (!segment)
1735 		goto error;
1736 
1737 	hw = &segment->hw;
1738 	hw->control = len;
1739 	hw->src_addr = dma_src;
1740 	hw->dest_addr = dma_dst;
1741 	if (chan->ext_addr) {
1742 		hw->src_addr_msb = upper_32_bits(dma_src);
1743 		hw->dest_addr_msb = upper_32_bits(dma_dst);
1744 	}
1745 
1746 	/* Insert the segment into the descriptor segments list. */
1747 	list_add_tail(&segment->node, &desc->segments);
1748 
1749 	desc->async_tx.phys = segment->phys;
1750 	hw->next_desc = segment->phys;
1751 
1752 	return &desc->async_tx;
1753 
1754 error:
1755 	xilinx_dma_free_tx_descriptor(chan, desc);
1756 	return NULL;
1757 }
1758 
1759 /**
1760  * xilinx_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
1761  * @dchan: DMA channel
1762  * @sgl: scatterlist to transfer to/from
1763  * @sg_len: number of entries in @scatterlist
1764  * @direction: DMA direction
1765  * @flags: transfer ack flags
1766  * @context: APP words of the descriptor
1767  *
1768  * Return: Async transaction descriptor on success and NULL on failure
1769  */
1770 static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
1771 	struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
1772 	enum dma_transfer_direction direction, unsigned long flags,
1773 	void *context)
1774 {
1775 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1776 	struct xilinx_dma_tx_descriptor *desc;
1777 	struct xilinx_axidma_tx_segment *segment = NULL;
1778 	u32 *app_w = (u32 *)context;
1779 	struct scatterlist *sg;
1780 	size_t copy;
1781 	size_t sg_used;
1782 	unsigned int i;
1783 
1784 	if (!is_slave_direction(direction))
1785 		return NULL;
1786 
1787 	/* Allocate a transaction descriptor. */
1788 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1789 	if (!desc)
1790 		return NULL;
1791 
1792 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1793 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1794 
1795 	/* Build transactions using information in the scatter gather list */
1796 	for_each_sg(sgl, sg, sg_len, i) {
1797 		sg_used = 0;
1798 
1799 		/* Loop until the entire scatterlist entry is used */
1800 		while (sg_used < sg_dma_len(sg)) {
1801 			struct xilinx_axidma_desc_hw *hw;
1802 
1803 			/* Get a free segment */
1804 			segment = xilinx_axidma_alloc_tx_segment(chan);
1805 			if (!segment)
1806 				goto error;
1807 
1808 			/*
1809 			 * Calculate the maximum number of bytes to transfer,
1810 			 * making sure it is less than the hw limit
1811 			 */
1812 			copy = xilinx_dma_calc_copysize(chan, sg_dma_len(sg),
1813 							sg_used);
1814 			hw = &segment->hw;
1815 
1816 			/* Fill in the descriptor */
1817 			xilinx_axidma_buf(chan, hw, sg_dma_address(sg),
1818 					  sg_used, 0);
1819 
1820 			hw->control = copy;
1821 
1822 			if (chan->direction == DMA_MEM_TO_DEV) {
1823 				if (app_w)
1824 					memcpy(hw->app, app_w, sizeof(u32) *
1825 					       XILINX_DMA_NUM_APP_WORDS);
1826 			}
1827 
1828 			sg_used += copy;
1829 
1830 			/*
1831 			 * Insert the segment into the descriptor segments
1832 			 * list.
1833 			 */
1834 			list_add_tail(&segment->node, &desc->segments);
1835 		}
1836 	}
1837 
1838 	segment = list_first_entry(&desc->segments,
1839 				   struct xilinx_axidma_tx_segment, node);
1840 	desc->async_tx.phys = segment->phys;
1841 
1842 	/* For the last DMA_MEM_TO_DEV transfer, set EOP */
1843 	if (chan->direction == DMA_MEM_TO_DEV) {
1844 		segment->hw.control |= XILINX_DMA_BD_SOP;
1845 		segment = list_last_entry(&desc->segments,
1846 					  struct xilinx_axidma_tx_segment,
1847 					  node);
1848 		segment->hw.control |= XILINX_DMA_BD_EOP;
1849 	}
1850 
1851 	return &desc->async_tx;
1852 
1853 error:
1854 	xilinx_dma_free_tx_descriptor(chan, desc);
1855 	return NULL;
1856 }
1857 
1858 /**
1859  * xilinx_dma_prep_dma_cyclic - prepare descriptors for a DMA_SLAVE transaction
1860  * @dchan: DMA channel
1861  * @buf_addr: Physical address of the buffer
1862  * @buf_len: Total length of the cyclic buffers
1863  * @period_len: length of individual cyclic buffer
1864  * @direction: DMA direction
1865  * @flags: transfer ack flags
1866  *
1867  * Return: Async transaction descriptor on success and NULL on failure
1868  */
1869 static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
1870 	struct dma_chan *dchan, dma_addr_t buf_addr, size_t buf_len,
1871 	size_t period_len, enum dma_transfer_direction direction,
1872 	unsigned long flags)
1873 {
1874 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1875 	struct xilinx_dma_tx_descriptor *desc;
1876 	struct xilinx_axidma_tx_segment *segment, *head_segment, *prev = NULL;
1877 	size_t copy, sg_used;
1878 	unsigned int num_periods;
1879 	int i;
1880 	u32 reg;
1881 
1882 	if (!period_len)
1883 		return NULL;
1884 
1885 	num_periods = buf_len / period_len;
1886 
1887 	if (!num_periods)
1888 		return NULL;
1889 
1890 	if (!is_slave_direction(direction))
1891 		return NULL;
1892 
1893 	/* Allocate a transaction descriptor. */
1894 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1895 	if (!desc)
1896 		return NULL;
1897 
1898 	chan->direction = direction;
1899 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1900 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1901 
1902 	for (i = 0; i < num_periods; ++i) {
1903 		sg_used = 0;
1904 
1905 		while (sg_used < period_len) {
1906 			struct xilinx_axidma_desc_hw *hw;
1907 
1908 			/* Get a free segment */
1909 			segment = xilinx_axidma_alloc_tx_segment(chan);
1910 			if (!segment)
1911 				goto error;
1912 
1913 			/*
1914 			 * Calculate the maximum number of bytes to transfer,
1915 			 * making sure it is less than the hw limit
1916 			 */
1917 			copy = xilinx_dma_calc_copysize(chan, period_len,
1918 							sg_used);
1919 			hw = &segment->hw;
1920 			xilinx_axidma_buf(chan, hw, buf_addr, sg_used,
1921 					  period_len * i);
1922 			hw->control = copy;
1923 
1924 			if (prev)
1925 				prev->hw.next_desc = segment->phys;
1926 
1927 			prev = segment;
1928 			sg_used += copy;
1929 
1930 			/*
1931 			 * Insert the segment into the descriptor segments
1932 			 * list.
1933 			 */
1934 			list_add_tail(&segment->node, &desc->segments);
1935 		}
1936 	}
1937 
1938 	head_segment = list_first_entry(&desc->segments,
1939 				   struct xilinx_axidma_tx_segment, node);
1940 	desc->async_tx.phys = head_segment->phys;
1941 
1942 	desc->cyclic = true;
1943 	reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
1944 	reg |= XILINX_DMA_CR_CYCLIC_BD_EN_MASK;
1945 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
1946 
1947 	segment = list_last_entry(&desc->segments,
1948 				  struct xilinx_axidma_tx_segment,
1949 				  node);
1950 	segment->hw.next_desc = (u32) head_segment->phys;
1951 
1952 	/* For the last DMA_MEM_TO_DEV transfer, set EOP */
1953 	if (direction == DMA_MEM_TO_DEV) {
1954 		head_segment->hw.control |= XILINX_DMA_BD_SOP;
1955 		segment->hw.control |= XILINX_DMA_BD_EOP;
1956 	}
1957 
1958 	return &desc->async_tx;
1959 
1960 error:
1961 	xilinx_dma_free_tx_descriptor(chan, desc);
1962 	return NULL;
1963 }
1964 
1965 /**
1966  * xilinx_dma_prep_interleaved - prepare a descriptor for a
1967  *	DMA_SLAVE transaction
1968  * @dchan: DMA channel
1969  * @xt: Interleaved template pointer
1970  * @flags: transfer ack flags
1971  *
1972  * Return: Async transaction descriptor on success and NULL on failure
1973  */
1974 static struct dma_async_tx_descriptor *
1975 xilinx_dma_prep_interleaved(struct dma_chan *dchan,
1976 				 struct dma_interleaved_template *xt,
1977 				 unsigned long flags)
1978 {
1979 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1980 	struct xilinx_dma_tx_descriptor *desc;
1981 	struct xilinx_axidma_tx_segment *segment;
1982 	struct xilinx_axidma_desc_hw *hw;
1983 
1984 	if (!is_slave_direction(xt->dir))
1985 		return NULL;
1986 
1987 	if (!xt->numf || !xt->sgl[0].size)
1988 		return NULL;
1989 
1990 	if (xt->frame_size != 1)
1991 		return NULL;
1992 
1993 	/* Allocate a transaction descriptor. */
1994 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1995 	if (!desc)
1996 		return NULL;
1997 
1998 	chan->direction = xt->dir;
1999 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
2000 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
2001 
2002 	/* Get a free segment */
2003 	segment = xilinx_axidma_alloc_tx_segment(chan);
2004 	if (!segment)
2005 		goto error;
2006 
2007 	hw = &segment->hw;
2008 
2009 	/* Fill in the descriptor */
2010 	if (xt->dir != DMA_MEM_TO_DEV)
2011 		hw->buf_addr = xt->dst_start;
2012 	else
2013 		hw->buf_addr = xt->src_start;
2014 
2015 	hw->mcdma_control = chan->tdest & XILINX_DMA_BD_TDEST_MASK;
2016 	hw->vsize_stride = (xt->numf << XILINX_DMA_BD_VSIZE_SHIFT) &
2017 			    XILINX_DMA_BD_VSIZE_MASK;
2018 	hw->vsize_stride |= (xt->sgl[0].icg + xt->sgl[0].size) &
2019 			    XILINX_DMA_BD_STRIDE_MASK;
2020 	hw->control = xt->sgl[0].size & XILINX_DMA_BD_HSIZE_MASK;
2021 
2022 	/*
2023 	 * Insert the segment into the descriptor segments
2024 	 * list.
2025 	 */
2026 	list_add_tail(&segment->node, &desc->segments);
2027 
2028 
2029 	segment = list_first_entry(&desc->segments,
2030 				   struct xilinx_axidma_tx_segment, node);
2031 	desc->async_tx.phys = segment->phys;
2032 
2033 	/* For the last DMA_MEM_TO_DEV transfer, set EOP */
2034 	if (xt->dir == DMA_MEM_TO_DEV) {
2035 		segment->hw.control |= XILINX_DMA_BD_SOP;
2036 		segment = list_last_entry(&desc->segments,
2037 					  struct xilinx_axidma_tx_segment,
2038 					  node);
2039 		segment->hw.control |= XILINX_DMA_BD_EOP;
2040 	}
2041 
2042 	return &desc->async_tx;
2043 
2044 error:
2045 	xilinx_dma_free_tx_descriptor(chan, desc);
2046 	return NULL;
2047 }
2048 
2049 /**
2050  * xilinx_dma_terminate_all - Halt the channel and free descriptors
2051  * @dchan: Driver specific DMA Channel pointer
2052  *
2053  * Return: '0' always.
2054  */
2055 static int xilinx_dma_terminate_all(struct dma_chan *dchan)
2056 {
2057 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
2058 	u32 reg;
2059 	int err;
2060 
2061 	if (chan->cyclic)
2062 		xilinx_dma_chan_reset(chan);
2063 
2064 	err = chan->stop_transfer(chan);
2065 	if (err) {
2066 		dev_err(chan->dev, "Cannot stop channel %p: %x\n",
2067 			chan, dma_ctrl_read(chan, XILINX_DMA_REG_DMASR));
2068 		chan->err = true;
2069 	}
2070 
2071 	/* Remove and free all of the descriptors in the lists */
2072 	xilinx_dma_free_descriptors(chan);
2073 	chan->idle = true;
2074 
2075 	if (chan->cyclic) {
2076 		reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
2077 		reg &= ~XILINX_DMA_CR_CYCLIC_BD_EN_MASK;
2078 		dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
2079 		chan->cyclic = false;
2080 	}
2081 
2082 	if ((chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) && chan->has_sg)
2083 		dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR,
2084 			     XILINX_CDMA_CR_SGMODE);
2085 
2086 	return 0;
2087 }
2088 
2089 /**
2090  * xilinx_dma_channel_set_config - Configure VDMA channel
2091  * Run-time configuration for Axi VDMA, supports:
2092  * . halt the channel
2093  * . configure interrupt coalescing and inter-packet delay threshold
2094  * . start/stop parking
2095  * . enable genlock
2096  *
2097  * @dchan: DMA channel
2098  * @cfg: VDMA device configuration pointer
2099  *
2100  * Return: '0' on success and failure value on error
2101  */
2102 int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
2103 					struct xilinx_vdma_config *cfg)
2104 {
2105 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
2106 	u32 dmacr;
2107 
2108 	if (cfg->reset)
2109 		return xilinx_dma_chan_reset(chan);
2110 
2111 	dmacr = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
2112 
2113 	chan->config.frm_dly = cfg->frm_dly;
2114 	chan->config.park = cfg->park;
2115 
2116 	/* genlock settings */
2117 	chan->config.gen_lock = cfg->gen_lock;
2118 	chan->config.master = cfg->master;
2119 
2120 	if (cfg->gen_lock && chan->genlock) {
2121 		dmacr |= XILINX_DMA_DMACR_GENLOCK_EN;
2122 		dmacr |= cfg->master << XILINX_DMA_DMACR_MASTER_SHIFT;
2123 	}
2124 
2125 	chan->config.frm_cnt_en = cfg->frm_cnt_en;
2126 	chan->config.vflip_en = cfg->vflip_en;
2127 
2128 	if (cfg->park)
2129 		chan->config.park_frm = cfg->park_frm;
2130 	else
2131 		chan->config.park_frm = -1;
2132 
2133 	chan->config.coalesc = cfg->coalesc;
2134 	chan->config.delay = cfg->delay;
2135 
2136 	if (cfg->coalesc <= XILINX_DMA_DMACR_FRAME_COUNT_MAX) {
2137 		dmacr |= cfg->coalesc << XILINX_DMA_DMACR_FRAME_COUNT_SHIFT;
2138 		chan->config.coalesc = cfg->coalesc;
2139 	}
2140 
2141 	if (cfg->delay <= XILINX_DMA_DMACR_DELAY_MAX) {
2142 		dmacr |= cfg->delay << XILINX_DMA_DMACR_DELAY_SHIFT;
2143 		chan->config.delay = cfg->delay;
2144 	}
2145 
2146 	/* FSync Source selection */
2147 	dmacr &= ~XILINX_DMA_DMACR_FSYNCSRC_MASK;
2148 	dmacr |= cfg->ext_fsync << XILINX_DMA_DMACR_FSYNCSRC_SHIFT;
2149 
2150 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, dmacr);
2151 
2152 	return 0;
2153 }
2154 EXPORT_SYMBOL(xilinx_vdma_channel_set_config);
2155 
2156 /* -----------------------------------------------------------------------------
2157  * Probe and remove
2158  */
2159 
2160 /**
2161  * xilinx_dma_chan_remove - Per Channel remove function
2162  * @chan: Driver specific DMA channel
2163  */
2164 static void xilinx_dma_chan_remove(struct xilinx_dma_chan *chan)
2165 {
2166 	/* Disable all interrupts */
2167 	dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR,
2168 		      XILINX_DMA_DMAXR_ALL_IRQ_MASK);
2169 
2170 	if (chan->irq > 0)
2171 		free_irq(chan->irq, chan);
2172 
2173 	tasklet_kill(&chan->tasklet);
2174 
2175 	list_del(&chan->common.device_node);
2176 }
2177 
2178 static int axidma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
2179 			    struct clk **tx_clk, struct clk **rx_clk,
2180 			    struct clk **sg_clk, struct clk **tmp_clk)
2181 {
2182 	int err;
2183 
2184 	*tmp_clk = NULL;
2185 
2186 	*axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
2187 	if (IS_ERR(*axi_clk)) {
2188 		err = PTR_ERR(*axi_clk);
2189 		dev_err(&pdev->dev, "failed to get axi_aclk (%d)\n", err);
2190 		return err;
2191 	}
2192 
2193 	*tx_clk = devm_clk_get(&pdev->dev, "m_axi_mm2s_aclk");
2194 	if (IS_ERR(*tx_clk))
2195 		*tx_clk = NULL;
2196 
2197 	*rx_clk = devm_clk_get(&pdev->dev, "m_axi_s2mm_aclk");
2198 	if (IS_ERR(*rx_clk))
2199 		*rx_clk = NULL;
2200 
2201 	*sg_clk = devm_clk_get(&pdev->dev, "m_axi_sg_aclk");
2202 	if (IS_ERR(*sg_clk))
2203 		*sg_clk = NULL;
2204 
2205 	err = clk_prepare_enable(*axi_clk);
2206 	if (err) {
2207 		dev_err(&pdev->dev, "failed to enable axi_clk (%d)\n", err);
2208 		return err;
2209 	}
2210 
2211 	err = clk_prepare_enable(*tx_clk);
2212 	if (err) {
2213 		dev_err(&pdev->dev, "failed to enable tx_clk (%d)\n", err);
2214 		goto err_disable_axiclk;
2215 	}
2216 
2217 	err = clk_prepare_enable(*rx_clk);
2218 	if (err) {
2219 		dev_err(&pdev->dev, "failed to enable rx_clk (%d)\n", err);
2220 		goto err_disable_txclk;
2221 	}
2222 
2223 	err = clk_prepare_enable(*sg_clk);
2224 	if (err) {
2225 		dev_err(&pdev->dev, "failed to enable sg_clk (%d)\n", err);
2226 		goto err_disable_rxclk;
2227 	}
2228 
2229 	return 0;
2230 
2231 err_disable_rxclk:
2232 	clk_disable_unprepare(*rx_clk);
2233 err_disable_txclk:
2234 	clk_disable_unprepare(*tx_clk);
2235 err_disable_axiclk:
2236 	clk_disable_unprepare(*axi_clk);
2237 
2238 	return err;
2239 }
2240 
2241 static int axicdma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
2242 			    struct clk **dev_clk, struct clk **tmp_clk,
2243 			    struct clk **tmp1_clk, struct clk **tmp2_clk)
2244 {
2245 	int err;
2246 
2247 	*tmp_clk = NULL;
2248 	*tmp1_clk = NULL;
2249 	*tmp2_clk = NULL;
2250 
2251 	*axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
2252 	if (IS_ERR(*axi_clk)) {
2253 		err = PTR_ERR(*axi_clk);
2254 		dev_err(&pdev->dev, "failed to get axi_clk (%d)\n", err);
2255 		return err;
2256 	}
2257 
2258 	*dev_clk = devm_clk_get(&pdev->dev, "m_axi_aclk");
2259 	if (IS_ERR(*dev_clk)) {
2260 		err = PTR_ERR(*dev_clk);
2261 		dev_err(&pdev->dev, "failed to get dev_clk (%d)\n", err);
2262 		return err;
2263 	}
2264 
2265 	err = clk_prepare_enable(*axi_clk);
2266 	if (err) {
2267 		dev_err(&pdev->dev, "failed to enable axi_clk (%d)\n", err);
2268 		return err;
2269 	}
2270 
2271 	err = clk_prepare_enable(*dev_clk);
2272 	if (err) {
2273 		dev_err(&pdev->dev, "failed to enable dev_clk (%d)\n", err);
2274 		goto err_disable_axiclk;
2275 	}
2276 
2277 	return 0;
2278 
2279 err_disable_axiclk:
2280 	clk_disable_unprepare(*axi_clk);
2281 
2282 	return err;
2283 }
2284 
2285 static int axivdma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
2286 			    struct clk **tx_clk, struct clk **txs_clk,
2287 			    struct clk **rx_clk, struct clk **rxs_clk)
2288 {
2289 	int err;
2290 
2291 	*axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
2292 	if (IS_ERR(*axi_clk)) {
2293 		err = PTR_ERR(*axi_clk);
2294 		dev_err(&pdev->dev, "failed to get axi_aclk (%d)\n", err);
2295 		return err;
2296 	}
2297 
2298 	*tx_clk = devm_clk_get(&pdev->dev, "m_axi_mm2s_aclk");
2299 	if (IS_ERR(*tx_clk))
2300 		*tx_clk = NULL;
2301 
2302 	*txs_clk = devm_clk_get(&pdev->dev, "m_axis_mm2s_aclk");
2303 	if (IS_ERR(*txs_clk))
2304 		*txs_clk = NULL;
2305 
2306 	*rx_clk = devm_clk_get(&pdev->dev, "m_axi_s2mm_aclk");
2307 	if (IS_ERR(*rx_clk))
2308 		*rx_clk = NULL;
2309 
2310 	*rxs_clk = devm_clk_get(&pdev->dev, "s_axis_s2mm_aclk");
2311 	if (IS_ERR(*rxs_clk))
2312 		*rxs_clk = NULL;
2313 
2314 	err = clk_prepare_enable(*axi_clk);
2315 	if (err) {
2316 		dev_err(&pdev->dev, "failed to enable axi_clk (%d)\n", err);
2317 		return err;
2318 	}
2319 
2320 	err = clk_prepare_enable(*tx_clk);
2321 	if (err) {
2322 		dev_err(&pdev->dev, "failed to enable tx_clk (%d)\n", err);
2323 		goto err_disable_axiclk;
2324 	}
2325 
2326 	err = clk_prepare_enable(*txs_clk);
2327 	if (err) {
2328 		dev_err(&pdev->dev, "failed to enable txs_clk (%d)\n", err);
2329 		goto err_disable_txclk;
2330 	}
2331 
2332 	err = clk_prepare_enable(*rx_clk);
2333 	if (err) {
2334 		dev_err(&pdev->dev, "failed to enable rx_clk (%d)\n", err);
2335 		goto err_disable_txsclk;
2336 	}
2337 
2338 	err = clk_prepare_enable(*rxs_clk);
2339 	if (err) {
2340 		dev_err(&pdev->dev, "failed to enable rxs_clk (%d)\n", err);
2341 		goto err_disable_rxclk;
2342 	}
2343 
2344 	return 0;
2345 
2346 err_disable_rxclk:
2347 	clk_disable_unprepare(*rx_clk);
2348 err_disable_txsclk:
2349 	clk_disable_unprepare(*txs_clk);
2350 err_disable_txclk:
2351 	clk_disable_unprepare(*tx_clk);
2352 err_disable_axiclk:
2353 	clk_disable_unprepare(*axi_clk);
2354 
2355 	return err;
2356 }
2357 
2358 static void xdma_disable_allclks(struct xilinx_dma_device *xdev)
2359 {
2360 	clk_disable_unprepare(xdev->rxs_clk);
2361 	clk_disable_unprepare(xdev->rx_clk);
2362 	clk_disable_unprepare(xdev->txs_clk);
2363 	clk_disable_unprepare(xdev->tx_clk);
2364 	clk_disable_unprepare(xdev->axi_clk);
2365 }
2366 
2367 /**
2368  * xilinx_dma_chan_probe - Per Channel Probing
2369  * It get channel features from the device tree entry and
2370  * initialize special channel handling routines
2371  *
2372  * @xdev: Driver specific device structure
2373  * @node: Device node
2374  * @chan_id: DMA Channel id
2375  *
2376  * Return: '0' on success and failure value on error
2377  */
2378 static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
2379 				  struct device_node *node, int chan_id)
2380 {
2381 	struct xilinx_dma_chan *chan;
2382 	bool has_dre = false;
2383 	u32 value, width;
2384 	int err;
2385 
2386 	/* Allocate and initialize the channel structure */
2387 	chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
2388 	if (!chan)
2389 		return -ENOMEM;
2390 
2391 	chan->dev = xdev->dev;
2392 	chan->xdev = xdev;
2393 	chan->desc_pendingcount = 0x0;
2394 	chan->ext_addr = xdev->ext_addr;
2395 	/* This variable ensures that descriptors are not
2396 	 * Submitted when dma engine is in progress. This variable is
2397 	 * Added to avoid polling for a bit in the status register to
2398 	 * Know dma state in the driver hot path.
2399 	 */
2400 	chan->idle = true;
2401 
2402 	spin_lock_init(&chan->lock);
2403 	INIT_LIST_HEAD(&chan->pending_list);
2404 	INIT_LIST_HEAD(&chan->done_list);
2405 	INIT_LIST_HEAD(&chan->active_list);
2406 	INIT_LIST_HEAD(&chan->free_seg_list);
2407 
2408 	/* Retrieve the channel properties from the device tree */
2409 	has_dre = of_property_read_bool(node, "xlnx,include-dre");
2410 
2411 	chan->genlock = of_property_read_bool(node, "xlnx,genlock-mode");
2412 
2413 	err = of_property_read_u32(node, "xlnx,datawidth", &value);
2414 	if (err) {
2415 		dev_err(xdev->dev, "missing xlnx,datawidth property\n");
2416 		return err;
2417 	}
2418 	width = value >> 3; /* Convert bits to bytes */
2419 
2420 	/* If data width is greater than 8 bytes, DRE is not in hw */
2421 	if (width > 8)
2422 		has_dre = false;
2423 
2424 	if (!has_dre)
2425 		xdev->common.copy_align = fls(width - 1);
2426 
2427 	if (of_device_is_compatible(node, "xlnx,axi-vdma-mm2s-channel") ||
2428 	    of_device_is_compatible(node, "xlnx,axi-dma-mm2s-channel") ||
2429 	    of_device_is_compatible(node, "xlnx,axi-cdma-channel")) {
2430 		chan->direction = DMA_MEM_TO_DEV;
2431 		chan->id = chan_id;
2432 		chan->tdest = chan_id;
2433 
2434 		chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET;
2435 		if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2436 			chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
2437 			chan->config.park = 1;
2438 
2439 			if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
2440 			    xdev->flush_on_fsync == XILINX_DMA_FLUSH_MM2S)
2441 				chan->flush_on_fsync = true;
2442 		}
2443 	} else if (of_device_is_compatible(node,
2444 					   "xlnx,axi-vdma-s2mm-channel") ||
2445 		   of_device_is_compatible(node,
2446 					   "xlnx,axi-dma-s2mm-channel")) {
2447 		chan->direction = DMA_DEV_TO_MEM;
2448 		chan->id = chan_id;
2449 		chan->tdest = chan_id - xdev->nr_channels;
2450 		chan->has_vflip = of_property_read_bool(node,
2451 					"xlnx,enable-vert-flip");
2452 		if (chan->has_vflip) {
2453 			chan->config.vflip_en = dma_read(chan,
2454 				XILINX_VDMA_REG_ENABLE_VERTICAL_FLIP) &
2455 				XILINX_VDMA_ENABLE_VERTICAL_FLIP;
2456 		}
2457 
2458 		chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET;
2459 		if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2460 			chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
2461 			chan->config.park = 1;
2462 
2463 			if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
2464 			    xdev->flush_on_fsync == XILINX_DMA_FLUSH_S2MM)
2465 				chan->flush_on_fsync = true;
2466 		}
2467 	} else {
2468 		dev_err(xdev->dev, "Invalid channel compatible node\n");
2469 		return -EINVAL;
2470 	}
2471 
2472 	/* Request the interrupt */
2473 	chan->irq = irq_of_parse_and_map(node, 0);
2474 	err = request_irq(chan->irq, xilinx_dma_irq_handler, IRQF_SHARED,
2475 			  "xilinx-dma-controller", chan);
2476 	if (err) {
2477 		dev_err(xdev->dev, "unable to request IRQ %d\n", chan->irq);
2478 		return err;
2479 	}
2480 
2481 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
2482 		chan->start_transfer = xilinx_dma_start_transfer;
2483 		chan->stop_transfer = xilinx_dma_stop_transfer;
2484 	} else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
2485 		chan->start_transfer = xilinx_cdma_start_transfer;
2486 		chan->stop_transfer = xilinx_cdma_stop_transfer;
2487 	} else {
2488 		chan->start_transfer = xilinx_vdma_start_transfer;
2489 		chan->stop_transfer = xilinx_dma_stop_transfer;
2490 	}
2491 
2492 	/* check if SG is enabled (only for AXIDMA and CDMA) */
2493 	if (xdev->dma_config->dmatype != XDMA_TYPE_VDMA) {
2494 		if (dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) &
2495 		    XILINX_DMA_DMASR_SG_MASK)
2496 			chan->has_sg = true;
2497 		dev_dbg(chan->dev, "ch %d: SG %s\n", chan->id,
2498 			chan->has_sg ? "enabled" : "disabled");
2499 	}
2500 
2501 	/* Initialize the tasklet */
2502 	tasklet_init(&chan->tasklet, xilinx_dma_do_tasklet,
2503 			(unsigned long)chan);
2504 
2505 	/*
2506 	 * Initialize the DMA channel and add it to the DMA engine channels
2507 	 * list.
2508 	 */
2509 	chan->common.device = &xdev->common;
2510 
2511 	list_add_tail(&chan->common.device_node, &xdev->common.channels);
2512 	xdev->chan[chan->id] = chan;
2513 
2514 	/* Reset the channel */
2515 	err = xilinx_dma_chan_reset(chan);
2516 	if (err < 0) {
2517 		dev_err(xdev->dev, "Reset channel failed\n");
2518 		return err;
2519 	}
2520 
2521 	return 0;
2522 }
2523 
2524 /**
2525  * xilinx_dma_child_probe - Per child node probe
2526  * It get number of dma-channels per child node from
2527  * device-tree and initializes all the channels.
2528  *
2529  * @xdev: Driver specific device structure
2530  * @node: Device node
2531  *
2532  * Return: 0 always.
2533  */
2534 static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
2535 				    struct device_node *node)
2536 {
2537 	int ret, i, nr_channels = 1;
2538 
2539 	ret = of_property_read_u32(node, "dma-channels", &nr_channels);
2540 	if ((ret < 0) && xdev->mcdma)
2541 		dev_warn(xdev->dev, "missing dma-channels property\n");
2542 
2543 	for (i = 0; i < nr_channels; i++)
2544 		xilinx_dma_chan_probe(xdev, node, xdev->chan_id++);
2545 
2546 	xdev->nr_channels += nr_channels;
2547 
2548 	return 0;
2549 }
2550 
2551 /**
2552  * of_dma_xilinx_xlate - Translation function
2553  * @dma_spec: Pointer to DMA specifier as found in the device tree
2554  * @ofdma: Pointer to DMA controller data
2555  *
2556  * Return: DMA channel pointer on success and NULL on error
2557  */
2558 static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
2559 						struct of_dma *ofdma)
2560 {
2561 	struct xilinx_dma_device *xdev = ofdma->of_dma_data;
2562 	int chan_id = dma_spec->args[0];
2563 
2564 	if (chan_id >= xdev->nr_channels || !xdev->chan[chan_id])
2565 		return NULL;
2566 
2567 	return dma_get_slave_channel(&xdev->chan[chan_id]->common);
2568 }
2569 
2570 static const struct xilinx_dma_config axidma_config = {
2571 	.dmatype = XDMA_TYPE_AXIDMA,
2572 	.clk_init = axidma_clk_init,
2573 };
2574 
2575 static const struct xilinx_dma_config axicdma_config = {
2576 	.dmatype = XDMA_TYPE_CDMA,
2577 	.clk_init = axicdma_clk_init,
2578 };
2579 
2580 static const struct xilinx_dma_config axivdma_config = {
2581 	.dmatype = XDMA_TYPE_VDMA,
2582 	.clk_init = axivdma_clk_init,
2583 };
2584 
2585 static const struct of_device_id xilinx_dma_of_ids[] = {
2586 	{ .compatible = "xlnx,axi-dma-1.00.a", .data = &axidma_config },
2587 	{ .compatible = "xlnx,axi-cdma-1.00.a", .data = &axicdma_config },
2588 	{ .compatible = "xlnx,axi-vdma-1.00.a", .data = &axivdma_config },
2589 	{}
2590 };
2591 MODULE_DEVICE_TABLE(of, xilinx_dma_of_ids);
2592 
2593 /**
2594  * xilinx_dma_probe - Driver probe function
2595  * @pdev: Pointer to the platform_device structure
2596  *
2597  * Return: '0' on success and failure value on error
2598  */
2599 static int xilinx_dma_probe(struct platform_device *pdev)
2600 {
2601 	int (*clk_init)(struct platform_device *, struct clk **, struct clk **,
2602 			struct clk **, struct clk **, struct clk **)
2603 					= axivdma_clk_init;
2604 	struct device_node *node = pdev->dev.of_node;
2605 	struct xilinx_dma_device *xdev;
2606 	struct device_node *child, *np = pdev->dev.of_node;
2607 	struct resource *io;
2608 	u32 num_frames, addr_width, len_width;
2609 	int i, err;
2610 
2611 	/* Allocate and initialize the DMA engine structure */
2612 	xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
2613 	if (!xdev)
2614 		return -ENOMEM;
2615 
2616 	xdev->dev = &pdev->dev;
2617 	if (np) {
2618 		const struct of_device_id *match;
2619 
2620 		match = of_match_node(xilinx_dma_of_ids, np);
2621 		if (match && match->data) {
2622 			xdev->dma_config = match->data;
2623 			clk_init = xdev->dma_config->clk_init;
2624 		}
2625 	}
2626 
2627 	err = clk_init(pdev, &xdev->axi_clk, &xdev->tx_clk, &xdev->txs_clk,
2628 		       &xdev->rx_clk, &xdev->rxs_clk);
2629 	if (err)
2630 		return err;
2631 
2632 	/* Request and map I/O memory */
2633 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2634 	xdev->regs = devm_ioremap_resource(&pdev->dev, io);
2635 	if (IS_ERR(xdev->regs))
2636 		return PTR_ERR(xdev->regs);
2637 
2638 	/* Retrieve the DMA engine properties from the device tree */
2639 	xdev->max_buffer_len = GENMASK(XILINX_DMA_MAX_TRANS_LEN_MAX - 1, 0);
2640 
2641 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
2642 		xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");
2643 		if (!of_property_read_u32(node, "xlnx,sg-length-width",
2644 					  &len_width)) {
2645 			if (len_width < XILINX_DMA_MAX_TRANS_LEN_MIN ||
2646 			    len_width > XILINX_DMA_V2_MAX_TRANS_LEN_MAX) {
2647 				dev_warn(xdev->dev,
2648 					 "invalid xlnx,sg-length-width property value. Using default width\n");
2649 			} else {
2650 				if (len_width > XILINX_DMA_MAX_TRANS_LEN_MAX)
2651 					dev_warn(xdev->dev, "Please ensure that IP supports buffer length > 23 bits\n");
2652 				xdev->max_buffer_len =
2653 					GENMASK(len_width - 1, 0);
2654 			}
2655 		}
2656 	}
2657 
2658 	if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2659 		err = of_property_read_u32(node, "xlnx,num-fstores",
2660 					   &num_frames);
2661 		if (err < 0) {
2662 			dev_err(xdev->dev,
2663 				"missing xlnx,num-fstores property\n");
2664 			return err;
2665 		}
2666 
2667 		err = of_property_read_u32(node, "xlnx,flush-fsync",
2668 					   &xdev->flush_on_fsync);
2669 		if (err < 0)
2670 			dev_warn(xdev->dev,
2671 				 "missing xlnx,flush-fsync property\n");
2672 	}
2673 
2674 	err = of_property_read_u32(node, "xlnx,addrwidth", &addr_width);
2675 	if (err < 0)
2676 		dev_warn(xdev->dev, "missing xlnx,addrwidth property\n");
2677 
2678 	if (addr_width > 32)
2679 		xdev->ext_addr = true;
2680 	else
2681 		xdev->ext_addr = false;
2682 
2683 	/* Set the dma mask bits */
2684 	dma_set_mask(xdev->dev, DMA_BIT_MASK(addr_width));
2685 
2686 	/* Initialize the DMA engine */
2687 	xdev->common.dev = &pdev->dev;
2688 
2689 	INIT_LIST_HEAD(&xdev->common.channels);
2690 	if (!(xdev->dma_config->dmatype == XDMA_TYPE_CDMA)) {
2691 		dma_cap_set(DMA_SLAVE, xdev->common.cap_mask);
2692 		dma_cap_set(DMA_PRIVATE, xdev->common.cap_mask);
2693 	}
2694 
2695 	xdev->common.device_alloc_chan_resources =
2696 				xilinx_dma_alloc_chan_resources;
2697 	xdev->common.device_free_chan_resources =
2698 				xilinx_dma_free_chan_resources;
2699 	xdev->common.device_terminate_all = xilinx_dma_terminate_all;
2700 	xdev->common.device_tx_status = xilinx_dma_tx_status;
2701 	xdev->common.device_issue_pending = xilinx_dma_issue_pending;
2702 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
2703 		dma_cap_set(DMA_CYCLIC, xdev->common.cap_mask);
2704 		xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg;
2705 		xdev->common.device_prep_dma_cyclic =
2706 					  xilinx_dma_prep_dma_cyclic;
2707 		xdev->common.device_prep_interleaved_dma =
2708 					xilinx_dma_prep_interleaved;
2709 		/* Residue calculation is supported by only AXI DMA */
2710 		xdev->common.residue_granularity =
2711 					  DMA_RESIDUE_GRANULARITY_SEGMENT;
2712 	} else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
2713 		dma_cap_set(DMA_MEMCPY, xdev->common.cap_mask);
2714 		xdev->common.device_prep_dma_memcpy = xilinx_cdma_prep_memcpy;
2715 	} else {
2716 		xdev->common.device_prep_interleaved_dma =
2717 				xilinx_vdma_dma_prep_interleaved;
2718 	}
2719 
2720 	platform_set_drvdata(pdev, xdev);
2721 
2722 	/* Initialize the channels */
2723 	for_each_child_of_node(node, child) {
2724 		err = xilinx_dma_child_probe(xdev, child);
2725 		if (err < 0)
2726 			goto disable_clks;
2727 	}
2728 
2729 	if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2730 		for (i = 0; i < xdev->nr_channels; i++)
2731 			if (xdev->chan[i])
2732 				xdev->chan[i]->num_frms = num_frames;
2733 	}
2734 
2735 	/* Register the DMA engine with the core */
2736 	dma_async_device_register(&xdev->common);
2737 
2738 	err = of_dma_controller_register(node, of_dma_xilinx_xlate,
2739 					 xdev);
2740 	if (err < 0) {
2741 		dev_err(&pdev->dev, "Unable to register DMA to DT\n");
2742 		dma_async_device_unregister(&xdev->common);
2743 		goto error;
2744 	}
2745 
2746 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
2747 		dev_info(&pdev->dev, "Xilinx AXI DMA Engine Driver Probed!!\n");
2748 	else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA)
2749 		dev_info(&pdev->dev, "Xilinx AXI CDMA Engine Driver Probed!!\n");
2750 	else
2751 		dev_info(&pdev->dev, "Xilinx AXI VDMA Engine Driver Probed!!\n");
2752 
2753 	return 0;
2754 
2755 disable_clks:
2756 	xdma_disable_allclks(xdev);
2757 error:
2758 	for (i = 0; i < xdev->nr_channels; i++)
2759 		if (xdev->chan[i])
2760 			xilinx_dma_chan_remove(xdev->chan[i]);
2761 
2762 	return err;
2763 }
2764 
2765 /**
2766  * xilinx_dma_remove - Driver remove function
2767  * @pdev: Pointer to the platform_device structure
2768  *
2769  * Return: Always '0'
2770  */
2771 static int xilinx_dma_remove(struct platform_device *pdev)
2772 {
2773 	struct xilinx_dma_device *xdev = platform_get_drvdata(pdev);
2774 	int i;
2775 
2776 	of_dma_controller_free(pdev->dev.of_node);
2777 
2778 	dma_async_device_unregister(&xdev->common);
2779 
2780 	for (i = 0; i < xdev->nr_channels; i++)
2781 		if (xdev->chan[i])
2782 			xilinx_dma_chan_remove(xdev->chan[i]);
2783 
2784 	xdma_disable_allclks(xdev);
2785 
2786 	return 0;
2787 }
2788 
2789 static struct platform_driver xilinx_vdma_driver = {
2790 	.driver = {
2791 		.name = "xilinx-vdma",
2792 		.of_match_table = xilinx_dma_of_ids,
2793 	},
2794 	.probe = xilinx_dma_probe,
2795 	.remove = xilinx_dma_remove,
2796 };
2797 
2798 module_platform_driver(xilinx_vdma_driver);
2799 
2800 MODULE_AUTHOR("Xilinx, Inc.");
2801 MODULE_DESCRIPTION("Xilinx VDMA driver");
2802 MODULE_LICENSE("GPL v2");
2803