xref: /openbmc/linux/drivers/dma/xilinx/xilinx_dma.c (revision 48c926cd)
1 /*
2  * DMA driver for Xilinx Video DMA Engine
3  *
4  * Copyright (C) 2010-2014 Xilinx, Inc. All rights reserved.
5  *
6  * Based on the Freescale DMA driver.
7  *
8  * Description:
9  * The AXI Video Direct Memory Access (AXI VDMA) core is a soft Xilinx IP
10  * core that provides high-bandwidth direct memory access between memory
11  * and AXI4-Stream type video target peripherals. The core provides efficient
12  * two dimensional DMA operations with independent asynchronous read (S2MM)
13  * and write (MM2S) channel operation. It can be configured to have either
14  * one channel or two channels. If configured as two channels, one is to
15  * transmit to the video device (MM2S) and another is to receive from the
16  * video device (S2MM). Initialization, status, interrupt and management
17  * registers are accessed through an AXI4-Lite slave interface.
18  *
19  * The AXI Direct Memory Access (AXI DMA) core is a soft Xilinx IP core that
20  * provides high-bandwidth one dimensional direct memory access between memory
21  * and AXI4-Stream target peripherals. It supports one receive and one
22  * transmit channel, both of them optional at synthesis time.
23  *
24  * The AXI CDMA, is a soft IP, which provides high-bandwidth Direct Memory
25  * Access (DMA) between a memory-mapped source address and a memory-mapped
26  * destination address.
27  *
28  * This program is free software: you can redistribute it and/or modify
29  * it under the terms of the GNU General Public License as published by
30  * the Free Software Foundation, either version 2 of the License, or
31  * (at your option) any later version.
32  */
33 
34 #include <linux/bitops.h>
35 #include <linux/dmapool.h>
36 #include <linux/dma/xilinx_dma.h>
37 #include <linux/init.h>
38 #include <linux/interrupt.h>
39 #include <linux/io.h>
40 #include <linux/iopoll.h>
41 #include <linux/module.h>
42 #include <linux/of_address.h>
43 #include <linux/of_dma.h>
44 #include <linux/of_platform.h>
45 #include <linux/of_irq.h>
46 #include <linux/slab.h>
47 #include <linux/clk.h>
48 #include <linux/io-64-nonatomic-lo-hi.h>
49 
50 #include "../dmaengine.h"
51 
52 /* Register/Descriptor Offsets */
53 #define XILINX_DMA_MM2S_CTRL_OFFSET		0x0000
54 #define XILINX_DMA_S2MM_CTRL_OFFSET		0x0030
55 #define XILINX_VDMA_MM2S_DESC_OFFSET		0x0050
56 #define XILINX_VDMA_S2MM_DESC_OFFSET		0x00a0
57 
58 /* Control Registers */
59 #define XILINX_DMA_REG_DMACR			0x0000
60 #define XILINX_DMA_DMACR_DELAY_MAX		0xff
61 #define XILINX_DMA_DMACR_DELAY_SHIFT		24
62 #define XILINX_DMA_DMACR_FRAME_COUNT_MAX	0xff
63 #define XILINX_DMA_DMACR_FRAME_COUNT_SHIFT	16
64 #define XILINX_DMA_DMACR_ERR_IRQ		BIT(14)
65 #define XILINX_DMA_DMACR_DLY_CNT_IRQ		BIT(13)
66 #define XILINX_DMA_DMACR_FRM_CNT_IRQ		BIT(12)
67 #define XILINX_DMA_DMACR_MASTER_SHIFT		8
68 #define XILINX_DMA_DMACR_FSYNCSRC_SHIFT	5
69 #define XILINX_DMA_DMACR_FRAMECNT_EN		BIT(4)
70 #define XILINX_DMA_DMACR_GENLOCK_EN		BIT(3)
71 #define XILINX_DMA_DMACR_RESET			BIT(2)
72 #define XILINX_DMA_DMACR_CIRC_EN		BIT(1)
73 #define XILINX_DMA_DMACR_RUNSTOP		BIT(0)
74 #define XILINX_DMA_DMACR_FSYNCSRC_MASK		GENMASK(6, 5)
75 
76 #define XILINX_DMA_REG_DMASR			0x0004
77 #define XILINX_DMA_DMASR_EOL_LATE_ERR		BIT(15)
78 #define XILINX_DMA_DMASR_ERR_IRQ		BIT(14)
79 #define XILINX_DMA_DMASR_DLY_CNT_IRQ		BIT(13)
80 #define XILINX_DMA_DMASR_FRM_CNT_IRQ		BIT(12)
81 #define XILINX_DMA_DMASR_SOF_LATE_ERR		BIT(11)
82 #define XILINX_DMA_DMASR_SG_DEC_ERR		BIT(10)
83 #define XILINX_DMA_DMASR_SG_SLV_ERR		BIT(9)
84 #define XILINX_DMA_DMASR_EOF_EARLY_ERR		BIT(8)
85 #define XILINX_DMA_DMASR_SOF_EARLY_ERR		BIT(7)
86 #define XILINX_DMA_DMASR_DMA_DEC_ERR		BIT(6)
87 #define XILINX_DMA_DMASR_DMA_SLAVE_ERR		BIT(5)
88 #define XILINX_DMA_DMASR_DMA_INT_ERR		BIT(4)
89 #define XILINX_DMA_DMASR_IDLE			BIT(1)
90 #define XILINX_DMA_DMASR_HALTED		BIT(0)
91 #define XILINX_DMA_DMASR_DELAY_MASK		GENMASK(31, 24)
92 #define XILINX_DMA_DMASR_FRAME_COUNT_MASK	GENMASK(23, 16)
93 
94 #define XILINX_DMA_REG_CURDESC			0x0008
95 #define XILINX_DMA_REG_TAILDESC		0x0010
96 #define XILINX_DMA_REG_REG_INDEX		0x0014
97 #define XILINX_DMA_REG_FRMSTORE		0x0018
98 #define XILINX_DMA_REG_THRESHOLD		0x001c
99 #define XILINX_DMA_REG_FRMPTR_STS		0x0024
100 #define XILINX_DMA_REG_PARK_PTR		0x0028
101 #define XILINX_DMA_PARK_PTR_WR_REF_SHIFT	8
102 #define XILINX_DMA_PARK_PTR_RD_REF_SHIFT	0
103 #define XILINX_DMA_REG_VDMA_VERSION		0x002c
104 
105 /* Register Direct Mode Registers */
106 #define XILINX_DMA_REG_VSIZE			0x0000
107 #define XILINX_DMA_REG_HSIZE			0x0004
108 
109 #define XILINX_DMA_REG_FRMDLY_STRIDE		0x0008
110 #define XILINX_DMA_FRMDLY_STRIDE_FRMDLY_SHIFT	24
111 #define XILINX_DMA_FRMDLY_STRIDE_STRIDE_SHIFT	0
112 
113 #define XILINX_VDMA_REG_START_ADDRESS(n)	(0x000c + 4 * (n))
114 #define XILINX_VDMA_REG_START_ADDRESS_64(n)	(0x000c + 8 * (n))
115 
116 /* HW specific definitions */
117 #define XILINX_DMA_MAX_CHANS_PER_DEVICE	0x20
118 
119 #define XILINX_DMA_DMAXR_ALL_IRQ_MASK	\
120 		(XILINX_DMA_DMASR_FRM_CNT_IRQ | \
121 		 XILINX_DMA_DMASR_DLY_CNT_IRQ | \
122 		 XILINX_DMA_DMASR_ERR_IRQ)
123 
124 #define XILINX_DMA_DMASR_ALL_ERR_MASK	\
125 		(XILINX_DMA_DMASR_EOL_LATE_ERR | \
126 		 XILINX_DMA_DMASR_SOF_LATE_ERR | \
127 		 XILINX_DMA_DMASR_SG_DEC_ERR | \
128 		 XILINX_DMA_DMASR_SG_SLV_ERR | \
129 		 XILINX_DMA_DMASR_EOF_EARLY_ERR | \
130 		 XILINX_DMA_DMASR_SOF_EARLY_ERR | \
131 		 XILINX_DMA_DMASR_DMA_DEC_ERR | \
132 		 XILINX_DMA_DMASR_DMA_SLAVE_ERR | \
133 		 XILINX_DMA_DMASR_DMA_INT_ERR)
134 
135 /*
136  * Recoverable errors are DMA Internal error, SOF Early, EOF Early
137  * and SOF Late. They are only recoverable when C_FLUSH_ON_FSYNC
138  * is enabled in the h/w system.
139  */
140 #define XILINX_DMA_DMASR_ERR_RECOVER_MASK	\
141 		(XILINX_DMA_DMASR_SOF_LATE_ERR | \
142 		 XILINX_DMA_DMASR_EOF_EARLY_ERR | \
143 		 XILINX_DMA_DMASR_SOF_EARLY_ERR | \
144 		 XILINX_DMA_DMASR_DMA_INT_ERR)
145 
146 /* Axi VDMA Flush on Fsync bits */
147 #define XILINX_DMA_FLUSH_S2MM		3
148 #define XILINX_DMA_FLUSH_MM2S		2
149 #define XILINX_DMA_FLUSH_BOTH		1
150 
151 /* Delay loop counter to prevent hardware failure */
152 #define XILINX_DMA_LOOP_COUNT		1000000
153 
154 /* AXI DMA Specific Registers/Offsets */
155 #define XILINX_DMA_REG_SRCDSTADDR	0x18
156 #define XILINX_DMA_REG_BTT		0x28
157 
158 /* AXI DMA Specific Masks/Bit fields */
159 #define XILINX_DMA_MAX_TRANS_LEN	GENMASK(22, 0)
160 #define XILINX_DMA_CR_COALESCE_MAX	GENMASK(23, 16)
161 #define XILINX_DMA_CR_CYCLIC_BD_EN_MASK	BIT(4)
162 #define XILINX_DMA_CR_COALESCE_SHIFT	16
163 #define XILINX_DMA_BD_SOP		BIT(27)
164 #define XILINX_DMA_BD_EOP		BIT(26)
165 #define XILINX_DMA_COALESCE_MAX		255
166 #define XILINX_DMA_NUM_APP_WORDS	5
167 
168 /* Multi-Channel DMA Descriptor offsets*/
169 #define XILINX_DMA_MCRX_CDESC(x)	(0x40 + (x-1) * 0x20)
170 #define XILINX_DMA_MCRX_TDESC(x)	(0x48 + (x-1) * 0x20)
171 
172 /* Multi-Channel DMA Masks/Shifts */
173 #define XILINX_DMA_BD_HSIZE_MASK	GENMASK(15, 0)
174 #define XILINX_DMA_BD_STRIDE_MASK	GENMASK(15, 0)
175 #define XILINX_DMA_BD_VSIZE_MASK	GENMASK(31, 19)
176 #define XILINX_DMA_BD_TDEST_MASK	GENMASK(4, 0)
177 #define XILINX_DMA_BD_STRIDE_SHIFT	0
178 #define XILINX_DMA_BD_VSIZE_SHIFT	19
179 
180 /* AXI CDMA Specific Registers/Offsets */
181 #define XILINX_CDMA_REG_SRCADDR		0x18
182 #define XILINX_CDMA_REG_DSTADDR		0x20
183 
184 /* AXI CDMA Specific Masks */
185 #define XILINX_CDMA_CR_SGMODE          BIT(3)
186 
187 /**
188  * struct xilinx_vdma_desc_hw - Hardware Descriptor
189  * @next_desc: Next Descriptor Pointer @0x00
190  * @pad1: Reserved @0x04
191  * @buf_addr: Buffer address @0x08
192  * @buf_addr_msb: MSB of Buffer address @0x0C
193  * @vsize: Vertical Size @0x10
194  * @hsize: Horizontal Size @0x14
195  * @stride: Number of bytes between the first
196  *	    pixels of each horizontal line @0x18
197  */
198 struct xilinx_vdma_desc_hw {
199 	u32 next_desc;
200 	u32 pad1;
201 	u32 buf_addr;
202 	u32 buf_addr_msb;
203 	u32 vsize;
204 	u32 hsize;
205 	u32 stride;
206 } __aligned(64);
207 
208 /**
209  * struct xilinx_axidma_desc_hw - Hardware Descriptor for AXI DMA
210  * @next_desc: Next Descriptor Pointer @0x00
211  * @next_desc_msb: MSB of Next Descriptor Pointer @0x04
212  * @buf_addr: Buffer address @0x08
213  * @buf_addr_msb: MSB of Buffer address @0x0C
214  * @pad1: Reserved @0x10
215  * @pad2: Reserved @0x14
216  * @control: Control field @0x18
217  * @status: Status field @0x1C
218  * @app: APP Fields @0x20 - 0x30
219  */
220 struct xilinx_axidma_desc_hw {
221 	u32 next_desc;
222 	u32 next_desc_msb;
223 	u32 buf_addr;
224 	u32 buf_addr_msb;
225 	u32 mcdma_control;
226 	u32 vsize_stride;
227 	u32 control;
228 	u32 status;
229 	u32 app[XILINX_DMA_NUM_APP_WORDS];
230 } __aligned(64);
231 
232 /**
233  * struct xilinx_cdma_desc_hw - Hardware Descriptor
234  * @next_desc: Next Descriptor Pointer @0x00
235  * @next_descmsb: Next Descriptor Pointer MSB @0x04
236  * @src_addr: Source address @0x08
237  * @src_addrmsb: Source address MSB @0x0C
238  * @dest_addr: Destination address @0x10
239  * @dest_addrmsb: Destination address MSB @0x14
240  * @control: Control field @0x18
241  * @status: Status field @0x1C
242  */
243 struct xilinx_cdma_desc_hw {
244 	u32 next_desc;
245 	u32 next_desc_msb;
246 	u32 src_addr;
247 	u32 src_addr_msb;
248 	u32 dest_addr;
249 	u32 dest_addr_msb;
250 	u32 control;
251 	u32 status;
252 } __aligned(64);
253 
254 /**
255  * struct xilinx_vdma_tx_segment - Descriptor segment
256  * @hw: Hardware descriptor
257  * @node: Node in the descriptor segments list
258  * @phys: Physical address of segment
259  */
260 struct xilinx_vdma_tx_segment {
261 	struct xilinx_vdma_desc_hw hw;
262 	struct list_head node;
263 	dma_addr_t phys;
264 } __aligned(64);
265 
266 /**
267  * struct xilinx_axidma_tx_segment - Descriptor segment
268  * @hw: Hardware descriptor
269  * @node: Node in the descriptor segments list
270  * @phys: Physical address of segment
271  */
272 struct xilinx_axidma_tx_segment {
273 	struct xilinx_axidma_desc_hw hw;
274 	struct list_head node;
275 	dma_addr_t phys;
276 } __aligned(64);
277 
278 /**
279  * struct xilinx_cdma_tx_segment - Descriptor segment
280  * @hw: Hardware descriptor
281  * @node: Node in the descriptor segments list
282  * @phys: Physical address of segment
283  */
284 struct xilinx_cdma_tx_segment {
285 	struct xilinx_cdma_desc_hw hw;
286 	struct list_head node;
287 	dma_addr_t phys;
288 } __aligned(64);
289 
290 /**
291  * struct xilinx_dma_tx_descriptor - Per Transaction structure
292  * @async_tx: Async transaction descriptor
293  * @segments: TX segments list
294  * @node: Node in the channel descriptors list
295  * @cyclic: Check for cyclic transfers.
296  */
297 struct xilinx_dma_tx_descriptor {
298 	struct dma_async_tx_descriptor async_tx;
299 	struct list_head segments;
300 	struct list_head node;
301 	bool cyclic;
302 };
303 
304 /**
305  * struct xilinx_dma_chan - Driver specific DMA channel structure
306  * @xdev: Driver specific device structure
307  * @ctrl_offset: Control registers offset
308  * @desc_offset: TX descriptor registers offset
309  * @lock: Descriptor operation lock
310  * @pending_list: Descriptors waiting
311  * @active_list: Descriptors ready to submit
312  * @done_list: Complete descriptors
313  * @common: DMA common channel
314  * @desc_pool: Descriptors pool
315  * @dev: The dma device
316  * @irq: Channel IRQ
317  * @id: Channel ID
318  * @direction: Transfer direction
319  * @num_frms: Number of frames
320  * @has_sg: Support scatter transfers
321  * @cyclic: Check for cyclic transfers.
322  * @genlock: Support genlock mode
323  * @err: Channel has errors
324  * @tasklet: Cleanup work after irq
325  * @config: Device configuration info
326  * @flush_on_fsync: Flush on Frame sync
327  * @desc_pendingcount: Descriptor pending count
328  * @ext_addr: Indicates 64 bit addressing is supported by dma channel
329  * @desc_submitcount: Descriptor h/w submitted count
330  * @residue: Residue for AXI DMA
331  * @seg_v: Statically allocated segments base
332  * @cyclic_seg_v: Statically allocated segment base for cyclic transfers
333  * @start_transfer: Differentiate b/w DMA IP's transfer
334  * @stop_transfer: Differentiate b/w DMA IP's quiesce
335  */
336 struct xilinx_dma_chan {
337 	struct xilinx_dma_device *xdev;
338 	u32 ctrl_offset;
339 	u32 desc_offset;
340 	spinlock_t lock;
341 	struct list_head pending_list;
342 	struct list_head active_list;
343 	struct list_head done_list;
344 	struct dma_chan common;
345 	struct dma_pool *desc_pool;
346 	struct device *dev;
347 	int irq;
348 	int id;
349 	enum dma_transfer_direction direction;
350 	int num_frms;
351 	bool has_sg;
352 	bool cyclic;
353 	bool genlock;
354 	bool err;
355 	struct tasklet_struct tasklet;
356 	struct xilinx_vdma_config config;
357 	bool flush_on_fsync;
358 	u32 desc_pendingcount;
359 	bool ext_addr;
360 	u32 desc_submitcount;
361 	u32 residue;
362 	struct xilinx_axidma_tx_segment *seg_v;
363 	struct xilinx_axidma_tx_segment *cyclic_seg_v;
364 	void (*start_transfer)(struct xilinx_dma_chan *chan);
365 	int (*stop_transfer)(struct xilinx_dma_chan *chan);
366 	u16 tdest;
367 };
368 
369 struct xilinx_dma_config {
370 	enum xdma_ip_type dmatype;
371 	int (*clk_init)(struct platform_device *pdev, struct clk **axi_clk,
372 			struct clk **tx_clk, struct clk **txs_clk,
373 			struct clk **rx_clk, struct clk **rxs_clk);
374 };
375 
376 /**
377  * struct xilinx_dma_device - DMA device structure
378  * @regs: I/O mapped base address
379  * @dev: Device Structure
380  * @common: DMA device structure
381  * @chan: Driver specific DMA channel
382  * @has_sg: Specifies whether Scatter-Gather is present or not
383  * @mcdma: Specifies whether Multi-Channel is present or not
384  * @flush_on_fsync: Flush on frame sync
385  * @ext_addr: Indicates 64 bit addressing is supported by dma device
386  * @pdev: Platform device structure pointer
387  * @dma_config: DMA config structure
388  * @axi_clk: DMA Axi4-lite interace clock
389  * @tx_clk: DMA mm2s clock
390  * @txs_clk: DMA mm2s stream clock
391  * @rx_clk: DMA s2mm clock
392  * @rxs_clk: DMA s2mm stream clock
393  * @nr_channels: Number of channels DMA device supports
394  * @chan_id: DMA channel identifier
395  */
396 struct xilinx_dma_device {
397 	void __iomem *regs;
398 	struct device *dev;
399 	struct dma_device common;
400 	struct xilinx_dma_chan *chan[XILINX_DMA_MAX_CHANS_PER_DEVICE];
401 	bool has_sg;
402 	bool mcdma;
403 	u32 flush_on_fsync;
404 	bool ext_addr;
405 	struct platform_device  *pdev;
406 	const struct xilinx_dma_config *dma_config;
407 	struct clk *axi_clk;
408 	struct clk *tx_clk;
409 	struct clk *txs_clk;
410 	struct clk *rx_clk;
411 	struct clk *rxs_clk;
412 	u32 nr_channels;
413 	u32 chan_id;
414 };
415 
416 /* Macros */
417 #define to_xilinx_chan(chan) \
418 	container_of(chan, struct xilinx_dma_chan, common)
419 #define to_dma_tx_descriptor(tx) \
420 	container_of(tx, struct xilinx_dma_tx_descriptor, async_tx)
421 #define xilinx_dma_poll_timeout(chan, reg, val, cond, delay_us, timeout_us) \
422 	readl_poll_timeout(chan->xdev->regs + chan->ctrl_offset + reg, val, \
423 			   cond, delay_us, timeout_us)
424 
425 /* IO accessors */
426 static inline u32 dma_read(struct xilinx_dma_chan *chan, u32 reg)
427 {
428 	return ioread32(chan->xdev->regs + reg);
429 }
430 
431 static inline void dma_write(struct xilinx_dma_chan *chan, u32 reg, u32 value)
432 {
433 	iowrite32(value, chan->xdev->regs + reg);
434 }
435 
436 static inline void vdma_desc_write(struct xilinx_dma_chan *chan, u32 reg,
437 				   u32 value)
438 {
439 	dma_write(chan, chan->desc_offset + reg, value);
440 }
441 
442 static inline u32 dma_ctrl_read(struct xilinx_dma_chan *chan, u32 reg)
443 {
444 	return dma_read(chan, chan->ctrl_offset + reg);
445 }
446 
447 static inline void dma_ctrl_write(struct xilinx_dma_chan *chan, u32 reg,
448 				   u32 value)
449 {
450 	dma_write(chan, chan->ctrl_offset + reg, value);
451 }
452 
453 static inline void dma_ctrl_clr(struct xilinx_dma_chan *chan, u32 reg,
454 				 u32 clr)
455 {
456 	dma_ctrl_write(chan, reg, dma_ctrl_read(chan, reg) & ~clr);
457 }
458 
459 static inline void dma_ctrl_set(struct xilinx_dma_chan *chan, u32 reg,
460 				 u32 set)
461 {
462 	dma_ctrl_write(chan, reg, dma_ctrl_read(chan, reg) | set);
463 }
464 
465 /**
466  * vdma_desc_write_64 - 64-bit descriptor write
467  * @chan: Driver specific VDMA channel
468  * @reg: Register to write
469  * @value_lsb: lower address of the descriptor.
470  * @value_msb: upper address of the descriptor.
471  *
472  * Since vdma driver is trying to write to a register offset which is not a
473  * multiple of 64 bits(ex : 0x5c), we are writing as two separate 32 bits
474  * instead of a single 64 bit register write.
475  */
476 static inline void vdma_desc_write_64(struct xilinx_dma_chan *chan, u32 reg,
477 				      u32 value_lsb, u32 value_msb)
478 {
479 	/* Write the lsb 32 bits*/
480 	writel(value_lsb, chan->xdev->regs + chan->desc_offset + reg);
481 
482 	/* Write the msb 32 bits */
483 	writel(value_msb, chan->xdev->regs + chan->desc_offset + reg + 4);
484 }
485 
486 static inline void dma_writeq(struct xilinx_dma_chan *chan, u32 reg, u64 value)
487 {
488 	lo_hi_writeq(value, chan->xdev->regs + chan->ctrl_offset + reg);
489 }
490 
491 static inline void xilinx_write(struct xilinx_dma_chan *chan, u32 reg,
492 				dma_addr_t addr)
493 {
494 	if (chan->ext_addr)
495 		dma_writeq(chan, reg, addr);
496 	else
497 		dma_ctrl_write(chan, reg, addr);
498 }
499 
500 static inline void xilinx_axidma_buf(struct xilinx_dma_chan *chan,
501 				     struct xilinx_axidma_desc_hw *hw,
502 				     dma_addr_t buf_addr, size_t sg_used,
503 				     size_t period_len)
504 {
505 	if (chan->ext_addr) {
506 		hw->buf_addr = lower_32_bits(buf_addr + sg_used + period_len);
507 		hw->buf_addr_msb = upper_32_bits(buf_addr + sg_used +
508 						 period_len);
509 	} else {
510 		hw->buf_addr = buf_addr + sg_used + period_len;
511 	}
512 }
513 
514 /* -----------------------------------------------------------------------------
515  * Descriptors and segments alloc and free
516  */
517 
518 /**
519  * xilinx_vdma_alloc_tx_segment - Allocate transaction segment
520  * @chan: Driver specific DMA channel
521  *
522  * Return: The allocated segment on success and NULL on failure.
523  */
524 static struct xilinx_vdma_tx_segment *
525 xilinx_vdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
526 {
527 	struct xilinx_vdma_tx_segment *segment;
528 	dma_addr_t phys;
529 
530 	segment = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &phys);
531 	if (!segment)
532 		return NULL;
533 
534 	segment->phys = phys;
535 
536 	return segment;
537 }
538 
539 /**
540  * xilinx_cdma_alloc_tx_segment - Allocate transaction segment
541  * @chan: Driver specific DMA channel
542  *
543  * Return: The allocated segment on success and NULL on failure.
544  */
545 static struct xilinx_cdma_tx_segment *
546 xilinx_cdma_alloc_tx_segment(struct xilinx_dma_chan *chan)
547 {
548 	struct xilinx_cdma_tx_segment *segment;
549 	dma_addr_t phys;
550 
551 	segment = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &phys);
552 	if (!segment)
553 		return NULL;
554 
555 	segment->phys = phys;
556 
557 	return segment;
558 }
559 
560 /**
561  * xilinx_axidma_alloc_tx_segment - Allocate transaction segment
562  * @chan: Driver specific DMA channel
563  *
564  * Return: The allocated segment on success and NULL on failure.
565  */
566 static struct xilinx_axidma_tx_segment *
567 xilinx_axidma_alloc_tx_segment(struct xilinx_dma_chan *chan)
568 {
569 	struct xilinx_axidma_tx_segment *segment;
570 	dma_addr_t phys;
571 
572 	segment = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &phys);
573 	if (!segment)
574 		return NULL;
575 
576 	segment->phys = phys;
577 
578 	return segment;
579 }
580 
581 /**
582  * xilinx_dma_free_tx_segment - Free transaction segment
583  * @chan: Driver specific DMA channel
584  * @segment: DMA transaction segment
585  */
586 static void xilinx_dma_free_tx_segment(struct xilinx_dma_chan *chan,
587 				struct xilinx_axidma_tx_segment *segment)
588 {
589 	dma_pool_free(chan->desc_pool, segment, segment->phys);
590 }
591 
592 /**
593  * xilinx_cdma_free_tx_segment - Free transaction segment
594  * @chan: Driver specific DMA channel
595  * @segment: DMA transaction segment
596  */
597 static void xilinx_cdma_free_tx_segment(struct xilinx_dma_chan *chan,
598 				struct xilinx_cdma_tx_segment *segment)
599 {
600 	dma_pool_free(chan->desc_pool, segment, segment->phys);
601 }
602 
603 /**
604  * xilinx_vdma_free_tx_segment - Free transaction segment
605  * @chan: Driver specific DMA channel
606  * @segment: DMA transaction segment
607  */
608 static void xilinx_vdma_free_tx_segment(struct xilinx_dma_chan *chan,
609 					struct xilinx_vdma_tx_segment *segment)
610 {
611 	dma_pool_free(chan->desc_pool, segment, segment->phys);
612 }
613 
614 /**
615  * xilinx_dma_tx_descriptor - Allocate transaction descriptor
616  * @chan: Driver specific DMA channel
617  *
618  * Return: The allocated descriptor on success and NULL on failure.
619  */
620 static struct xilinx_dma_tx_descriptor *
621 xilinx_dma_alloc_tx_descriptor(struct xilinx_dma_chan *chan)
622 {
623 	struct xilinx_dma_tx_descriptor *desc;
624 
625 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
626 	if (!desc)
627 		return NULL;
628 
629 	INIT_LIST_HEAD(&desc->segments);
630 
631 	return desc;
632 }
633 
634 /**
635  * xilinx_dma_free_tx_descriptor - Free transaction descriptor
636  * @chan: Driver specific DMA channel
637  * @desc: DMA transaction descriptor
638  */
639 static void
640 xilinx_dma_free_tx_descriptor(struct xilinx_dma_chan *chan,
641 			       struct xilinx_dma_tx_descriptor *desc)
642 {
643 	struct xilinx_vdma_tx_segment *segment, *next;
644 	struct xilinx_cdma_tx_segment *cdma_segment, *cdma_next;
645 	struct xilinx_axidma_tx_segment *axidma_segment, *axidma_next;
646 
647 	if (!desc)
648 		return;
649 
650 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
651 		list_for_each_entry_safe(segment, next, &desc->segments, node) {
652 			list_del(&segment->node);
653 			xilinx_vdma_free_tx_segment(chan, segment);
654 		}
655 	} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
656 		list_for_each_entry_safe(cdma_segment, cdma_next,
657 					 &desc->segments, node) {
658 			list_del(&cdma_segment->node);
659 			xilinx_cdma_free_tx_segment(chan, cdma_segment);
660 		}
661 	} else {
662 		list_for_each_entry_safe(axidma_segment, axidma_next,
663 					 &desc->segments, node) {
664 			list_del(&axidma_segment->node);
665 			xilinx_dma_free_tx_segment(chan, axidma_segment);
666 		}
667 	}
668 
669 	kfree(desc);
670 }
671 
672 /* Required functions */
673 
674 /**
675  * xilinx_dma_free_desc_list - Free descriptors list
676  * @chan: Driver specific DMA channel
677  * @list: List to parse and delete the descriptor
678  */
679 static void xilinx_dma_free_desc_list(struct xilinx_dma_chan *chan,
680 					struct list_head *list)
681 {
682 	struct xilinx_dma_tx_descriptor *desc, *next;
683 
684 	list_for_each_entry_safe(desc, next, list, node) {
685 		list_del(&desc->node);
686 		xilinx_dma_free_tx_descriptor(chan, desc);
687 	}
688 }
689 
690 /**
691  * xilinx_dma_free_descriptors - Free channel descriptors
692  * @chan: Driver specific DMA channel
693  */
694 static void xilinx_dma_free_descriptors(struct xilinx_dma_chan *chan)
695 {
696 	unsigned long flags;
697 
698 	spin_lock_irqsave(&chan->lock, flags);
699 
700 	xilinx_dma_free_desc_list(chan, &chan->pending_list);
701 	xilinx_dma_free_desc_list(chan, &chan->done_list);
702 	xilinx_dma_free_desc_list(chan, &chan->active_list);
703 
704 	spin_unlock_irqrestore(&chan->lock, flags);
705 }
706 
707 /**
708  * xilinx_dma_free_chan_resources - Free channel resources
709  * @dchan: DMA channel
710  */
711 static void xilinx_dma_free_chan_resources(struct dma_chan *dchan)
712 {
713 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
714 
715 	dev_dbg(chan->dev, "Free all channel resources.\n");
716 
717 	xilinx_dma_free_descriptors(chan);
718 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
719 		xilinx_dma_free_tx_segment(chan, chan->cyclic_seg_v);
720 		xilinx_dma_free_tx_segment(chan, chan->seg_v);
721 	}
722 	dma_pool_destroy(chan->desc_pool);
723 	chan->desc_pool = NULL;
724 }
725 
726 /**
727  * xilinx_dma_chan_handle_cyclic - Cyclic dma callback
728  * @chan: Driver specific dma channel
729  * @desc: dma transaction descriptor
730  * @flags: flags for spin lock
731  */
732 static void xilinx_dma_chan_handle_cyclic(struct xilinx_dma_chan *chan,
733 					  struct xilinx_dma_tx_descriptor *desc,
734 					  unsigned long *flags)
735 {
736 	dma_async_tx_callback callback;
737 	void *callback_param;
738 
739 	callback = desc->async_tx.callback;
740 	callback_param = desc->async_tx.callback_param;
741 	if (callback) {
742 		spin_unlock_irqrestore(&chan->lock, *flags);
743 		callback(callback_param);
744 		spin_lock_irqsave(&chan->lock, *flags);
745 	}
746 }
747 
748 /**
749  * xilinx_dma_chan_desc_cleanup - Clean channel descriptors
750  * @chan: Driver specific DMA channel
751  */
752 static void xilinx_dma_chan_desc_cleanup(struct xilinx_dma_chan *chan)
753 {
754 	struct xilinx_dma_tx_descriptor *desc, *next;
755 	unsigned long flags;
756 
757 	spin_lock_irqsave(&chan->lock, flags);
758 
759 	list_for_each_entry_safe(desc, next, &chan->done_list, node) {
760 		struct dmaengine_desc_callback cb;
761 
762 		if (desc->cyclic) {
763 			xilinx_dma_chan_handle_cyclic(chan, desc, &flags);
764 			break;
765 		}
766 
767 		/* Remove from the list of running transactions */
768 		list_del(&desc->node);
769 
770 		/* Run the link descriptor callback function */
771 		dmaengine_desc_get_callback(&desc->async_tx, &cb);
772 		if (dmaengine_desc_callback_valid(&cb)) {
773 			spin_unlock_irqrestore(&chan->lock, flags);
774 			dmaengine_desc_callback_invoke(&cb, NULL);
775 			spin_lock_irqsave(&chan->lock, flags);
776 		}
777 
778 		/* Run any dependencies, then free the descriptor */
779 		dma_run_dependencies(&desc->async_tx);
780 		xilinx_dma_free_tx_descriptor(chan, desc);
781 	}
782 
783 	spin_unlock_irqrestore(&chan->lock, flags);
784 }
785 
786 /**
787  * xilinx_dma_do_tasklet - Schedule completion tasklet
788  * @data: Pointer to the Xilinx DMA channel structure
789  */
790 static void xilinx_dma_do_tasklet(unsigned long data)
791 {
792 	struct xilinx_dma_chan *chan = (struct xilinx_dma_chan *)data;
793 
794 	xilinx_dma_chan_desc_cleanup(chan);
795 }
796 
797 /**
798  * xilinx_dma_alloc_chan_resources - Allocate channel resources
799  * @dchan: DMA channel
800  *
801  * Return: '0' on success and failure value on error
802  */
803 static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
804 {
805 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
806 
807 	/* Has this channel already been allocated? */
808 	if (chan->desc_pool)
809 		return 0;
810 
811 	/*
812 	 * We need the descriptor to be aligned to 64bytes
813 	 * for meeting Xilinx VDMA specification requirement.
814 	 */
815 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
816 		chan->desc_pool = dma_pool_create("xilinx_dma_desc_pool",
817 				   chan->dev,
818 				   sizeof(struct xilinx_axidma_tx_segment),
819 				   __alignof__(struct xilinx_axidma_tx_segment),
820 				   0);
821 	} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
822 		chan->desc_pool = dma_pool_create("xilinx_cdma_desc_pool",
823 				   chan->dev,
824 				   sizeof(struct xilinx_cdma_tx_segment),
825 				   __alignof__(struct xilinx_cdma_tx_segment),
826 				   0);
827 	} else {
828 		chan->desc_pool = dma_pool_create("xilinx_vdma_desc_pool",
829 				     chan->dev,
830 				     sizeof(struct xilinx_vdma_tx_segment),
831 				     __alignof__(struct xilinx_vdma_tx_segment),
832 				     0);
833 	}
834 
835 	if (!chan->desc_pool) {
836 		dev_err(chan->dev,
837 			"unable to allocate channel %d descriptor pool\n",
838 			chan->id);
839 		return -ENOMEM;
840 	}
841 
842 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
843 		/*
844 		 * For AXI DMA case after submitting a pending_list, keep
845 		 * an extra segment allocated so that the "next descriptor"
846 		 * pointer on the tail descriptor always points to a
847 		 * valid descriptor, even when paused after reaching taildesc.
848 		 * This way, it is possible to issue additional
849 		 * transfers without halting and restarting the channel.
850 		 */
851 		chan->seg_v = xilinx_axidma_alloc_tx_segment(chan);
852 
853 		/*
854 		 * For cyclic DMA mode we need to program the tail Descriptor
855 		 * register with a value which is not a part of the BD chain
856 		 * so allocating a desc segment during channel allocation for
857 		 * programming tail descriptor.
858 		 */
859 		chan->cyclic_seg_v = xilinx_axidma_alloc_tx_segment(chan);
860 	}
861 
862 	dma_cookie_init(dchan);
863 
864 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
865 		/* For AXI DMA resetting once channel will reset the
866 		 * other channel as well so enable the interrupts here.
867 		 */
868 		dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
869 			      XILINX_DMA_DMAXR_ALL_IRQ_MASK);
870 	}
871 
872 	if ((chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) && chan->has_sg)
873 		dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
874 			     XILINX_CDMA_CR_SGMODE);
875 
876 	return 0;
877 }
878 
879 /**
880  * xilinx_dma_tx_status - Get DMA transaction status
881  * @dchan: DMA channel
882  * @cookie: Transaction identifier
883  * @txstate: Transaction state
884  *
885  * Return: DMA transaction status
886  */
887 static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan,
888 					dma_cookie_t cookie,
889 					struct dma_tx_state *txstate)
890 {
891 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
892 	struct xilinx_dma_tx_descriptor *desc;
893 	struct xilinx_axidma_tx_segment *segment;
894 	struct xilinx_axidma_desc_hw *hw;
895 	enum dma_status ret;
896 	unsigned long flags;
897 	u32 residue = 0;
898 
899 	ret = dma_cookie_status(dchan, cookie, txstate);
900 	if (ret == DMA_COMPLETE || !txstate)
901 		return ret;
902 
903 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
904 		spin_lock_irqsave(&chan->lock, flags);
905 
906 		desc = list_last_entry(&chan->active_list,
907 				       struct xilinx_dma_tx_descriptor, node);
908 		if (chan->has_sg) {
909 			list_for_each_entry(segment, &desc->segments, node) {
910 				hw = &segment->hw;
911 				residue += (hw->control - hw->status) &
912 					   XILINX_DMA_MAX_TRANS_LEN;
913 			}
914 		}
915 		spin_unlock_irqrestore(&chan->lock, flags);
916 
917 		chan->residue = residue;
918 		dma_set_residue(txstate, chan->residue);
919 	}
920 
921 	return ret;
922 }
923 
924 /**
925  * xilinx_dma_is_running - Check if DMA channel is running
926  * @chan: Driver specific DMA channel
927  *
928  * Return: '1' if running, '0' if not.
929  */
930 static bool xilinx_dma_is_running(struct xilinx_dma_chan *chan)
931 {
932 	return !(dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) &
933 		 XILINX_DMA_DMASR_HALTED) &&
934 		(dma_ctrl_read(chan, XILINX_DMA_REG_DMACR) &
935 		 XILINX_DMA_DMACR_RUNSTOP);
936 }
937 
938 /**
939  * xilinx_dma_is_idle - Check if DMA channel is idle
940  * @chan: Driver specific DMA channel
941  *
942  * Return: '1' if idle, '0' if not.
943  */
944 static bool xilinx_dma_is_idle(struct xilinx_dma_chan *chan)
945 {
946 	return dma_ctrl_read(chan, XILINX_DMA_REG_DMASR) &
947 		XILINX_DMA_DMASR_IDLE;
948 }
949 
950 /**
951  * xilinx_dma_stop_transfer - Halt DMA channel
952  * @chan: Driver specific DMA channel
953  */
954 static int xilinx_dma_stop_transfer(struct xilinx_dma_chan *chan)
955 {
956 	u32 val;
957 
958 	dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR, XILINX_DMA_DMACR_RUNSTOP);
959 
960 	/* Wait for the hardware to halt */
961 	return xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMASR, val,
962 				       val & XILINX_DMA_DMASR_HALTED, 0,
963 				       XILINX_DMA_LOOP_COUNT);
964 }
965 
966 /**
967  * xilinx_cdma_stop_transfer - Wait for the current transfer to complete
968  * @chan: Driver specific DMA channel
969  */
970 static int xilinx_cdma_stop_transfer(struct xilinx_dma_chan *chan)
971 {
972 	u32 val;
973 
974 	return xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMASR, val,
975 				       val & XILINX_DMA_DMASR_IDLE, 0,
976 				       XILINX_DMA_LOOP_COUNT);
977 }
978 
979 /**
980  * xilinx_dma_start - Start DMA channel
981  * @chan: Driver specific DMA channel
982  */
983 static void xilinx_dma_start(struct xilinx_dma_chan *chan)
984 {
985 	int err;
986 	u32 val;
987 
988 	dma_ctrl_set(chan, XILINX_DMA_REG_DMACR, XILINX_DMA_DMACR_RUNSTOP);
989 
990 	/* Wait for the hardware to start */
991 	err = xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMASR, val,
992 				      !(val & XILINX_DMA_DMASR_HALTED), 0,
993 				      XILINX_DMA_LOOP_COUNT);
994 
995 	if (err) {
996 		dev_err(chan->dev, "Cannot start channel %p: %x\n",
997 			chan, dma_ctrl_read(chan, XILINX_DMA_REG_DMASR));
998 
999 		chan->err = true;
1000 	}
1001 }
1002 
1003 /**
1004  * xilinx_vdma_start_transfer - Starts VDMA transfer
1005  * @chan: Driver specific channel struct pointer
1006  */
1007 static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
1008 {
1009 	struct xilinx_vdma_config *config = &chan->config;
1010 	struct xilinx_dma_tx_descriptor *desc, *tail_desc;
1011 	u32 reg;
1012 	struct xilinx_vdma_tx_segment *tail_segment;
1013 
1014 	/* This function was invoked with lock held */
1015 	if (chan->err)
1016 		return;
1017 
1018 	if (list_empty(&chan->pending_list))
1019 		return;
1020 
1021 	desc = list_first_entry(&chan->pending_list,
1022 				struct xilinx_dma_tx_descriptor, node);
1023 	tail_desc = list_last_entry(&chan->pending_list,
1024 				    struct xilinx_dma_tx_descriptor, node);
1025 
1026 	tail_segment = list_last_entry(&tail_desc->segments,
1027 				       struct xilinx_vdma_tx_segment, node);
1028 
1029 	/* If it is SG mode and hardware is busy, cannot submit */
1030 	if (chan->has_sg && xilinx_dma_is_running(chan) &&
1031 	    !xilinx_dma_is_idle(chan)) {
1032 		dev_dbg(chan->dev, "DMA controller still busy\n");
1033 		return;
1034 	}
1035 
1036 	/*
1037 	 * If hardware is idle, then all descriptors on the running lists are
1038 	 * done, start new transfers
1039 	 */
1040 	if (chan->has_sg)
1041 		dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
1042 				desc->async_tx.phys);
1043 
1044 	/* Configure the hardware using info in the config structure */
1045 	reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
1046 
1047 	if (config->frm_cnt_en)
1048 		reg |= XILINX_DMA_DMACR_FRAMECNT_EN;
1049 	else
1050 		reg &= ~XILINX_DMA_DMACR_FRAMECNT_EN;
1051 
1052 	/* Configure channel to allow number frame buffers */
1053 	dma_ctrl_write(chan, XILINX_DMA_REG_FRMSTORE,
1054 			chan->desc_pendingcount);
1055 
1056 	/*
1057 	 * With SG, start with circular mode, so that BDs can be fetched.
1058 	 * In direct register mode, if not parking, enable circular mode
1059 	 */
1060 	if (chan->has_sg || !config->park)
1061 		reg |= XILINX_DMA_DMACR_CIRC_EN;
1062 
1063 	if (config->park)
1064 		reg &= ~XILINX_DMA_DMACR_CIRC_EN;
1065 
1066 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
1067 
1068 	if (config->park && (config->park_frm >= 0) &&
1069 			(config->park_frm < chan->num_frms)) {
1070 		if (chan->direction == DMA_MEM_TO_DEV)
1071 			dma_write(chan, XILINX_DMA_REG_PARK_PTR,
1072 				config->park_frm <<
1073 					XILINX_DMA_PARK_PTR_RD_REF_SHIFT);
1074 		else
1075 			dma_write(chan, XILINX_DMA_REG_PARK_PTR,
1076 				config->park_frm <<
1077 					XILINX_DMA_PARK_PTR_WR_REF_SHIFT);
1078 	}
1079 
1080 	/* Start the hardware */
1081 	xilinx_dma_start(chan);
1082 
1083 	if (chan->err)
1084 		return;
1085 
1086 	/* Start the transfer */
1087 	if (chan->has_sg) {
1088 		dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
1089 				tail_segment->phys);
1090 	} else {
1091 		struct xilinx_vdma_tx_segment *segment, *last = NULL;
1092 		int i = 0;
1093 
1094 		if (chan->desc_submitcount < chan->num_frms)
1095 			i = chan->desc_submitcount;
1096 
1097 		list_for_each_entry(segment, &desc->segments, node) {
1098 			if (chan->ext_addr)
1099 				vdma_desc_write_64(chan,
1100 					XILINX_VDMA_REG_START_ADDRESS_64(i++),
1101 					segment->hw.buf_addr,
1102 					segment->hw.buf_addr_msb);
1103 			else
1104 				vdma_desc_write(chan,
1105 					XILINX_VDMA_REG_START_ADDRESS(i++),
1106 					segment->hw.buf_addr);
1107 
1108 			last = segment;
1109 		}
1110 
1111 		if (!last)
1112 			return;
1113 
1114 		/* HW expects these parameters to be same for one transaction */
1115 		vdma_desc_write(chan, XILINX_DMA_REG_HSIZE, last->hw.hsize);
1116 		vdma_desc_write(chan, XILINX_DMA_REG_FRMDLY_STRIDE,
1117 				last->hw.stride);
1118 		vdma_desc_write(chan, XILINX_DMA_REG_VSIZE, last->hw.vsize);
1119 	}
1120 
1121 	if (!chan->has_sg) {
1122 		list_del(&desc->node);
1123 		list_add_tail(&desc->node, &chan->active_list);
1124 		chan->desc_submitcount++;
1125 		chan->desc_pendingcount--;
1126 		if (chan->desc_submitcount == chan->num_frms)
1127 			chan->desc_submitcount = 0;
1128 	} else {
1129 		list_splice_tail_init(&chan->pending_list, &chan->active_list);
1130 		chan->desc_pendingcount = 0;
1131 	}
1132 }
1133 
1134 /**
1135  * xilinx_cdma_start_transfer - Starts cdma transfer
1136  * @chan: Driver specific channel struct pointer
1137  */
1138 static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
1139 {
1140 	struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
1141 	struct xilinx_cdma_tx_segment *tail_segment;
1142 	u32 ctrl_reg = dma_read(chan, XILINX_DMA_REG_DMACR);
1143 
1144 	if (chan->err)
1145 		return;
1146 
1147 	if (list_empty(&chan->pending_list))
1148 		return;
1149 
1150 	head_desc = list_first_entry(&chan->pending_list,
1151 				     struct xilinx_dma_tx_descriptor, node);
1152 	tail_desc = list_last_entry(&chan->pending_list,
1153 				    struct xilinx_dma_tx_descriptor, node);
1154 	tail_segment = list_last_entry(&tail_desc->segments,
1155 				       struct xilinx_cdma_tx_segment, node);
1156 
1157 	if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
1158 		ctrl_reg &= ~XILINX_DMA_CR_COALESCE_MAX;
1159 		ctrl_reg |= chan->desc_pendingcount <<
1160 				XILINX_DMA_CR_COALESCE_SHIFT;
1161 		dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, ctrl_reg);
1162 	}
1163 
1164 	if (chan->has_sg) {
1165 		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
1166 			     head_desc->async_tx.phys);
1167 
1168 		/* Update tail ptr register which will start the transfer */
1169 		xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
1170 			     tail_segment->phys);
1171 	} else {
1172 		/* In simple mode */
1173 		struct xilinx_cdma_tx_segment *segment;
1174 		struct xilinx_cdma_desc_hw *hw;
1175 
1176 		segment = list_first_entry(&head_desc->segments,
1177 					   struct xilinx_cdma_tx_segment,
1178 					   node);
1179 
1180 		hw = &segment->hw;
1181 
1182 		xilinx_write(chan, XILINX_CDMA_REG_SRCADDR, hw->src_addr);
1183 		xilinx_write(chan, XILINX_CDMA_REG_DSTADDR, hw->dest_addr);
1184 
1185 		/* Start the transfer */
1186 		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
1187 				hw->control & XILINX_DMA_MAX_TRANS_LEN);
1188 	}
1189 
1190 	list_splice_tail_init(&chan->pending_list, &chan->active_list);
1191 	chan->desc_pendingcount = 0;
1192 }
1193 
1194 /**
1195  * xilinx_dma_start_transfer - Starts DMA transfer
1196  * @chan: Driver specific channel struct pointer
1197  */
1198 static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
1199 {
1200 	struct xilinx_dma_tx_descriptor *head_desc, *tail_desc;
1201 	struct xilinx_axidma_tx_segment *tail_segment, *old_head, *new_head;
1202 	u32 reg;
1203 
1204 	if (chan->err)
1205 		return;
1206 
1207 	if (list_empty(&chan->pending_list))
1208 		return;
1209 
1210 	/* If it is SG mode and hardware is busy, cannot submit */
1211 	if (chan->has_sg && xilinx_dma_is_running(chan) &&
1212 	    !xilinx_dma_is_idle(chan)) {
1213 		dev_dbg(chan->dev, "DMA controller still busy\n");
1214 		return;
1215 	}
1216 
1217 	head_desc = list_first_entry(&chan->pending_list,
1218 				     struct xilinx_dma_tx_descriptor, node);
1219 	tail_desc = list_last_entry(&chan->pending_list,
1220 				    struct xilinx_dma_tx_descriptor, node);
1221 	tail_segment = list_last_entry(&tail_desc->segments,
1222 				       struct xilinx_axidma_tx_segment, node);
1223 
1224 	if (chan->has_sg && !chan->xdev->mcdma) {
1225 		old_head = list_first_entry(&head_desc->segments,
1226 					struct xilinx_axidma_tx_segment, node);
1227 		new_head = chan->seg_v;
1228 		/* Copy Buffer Descriptor fields. */
1229 		new_head->hw = old_head->hw;
1230 
1231 		/* Swap and save new reserve */
1232 		list_replace_init(&old_head->node, &new_head->node);
1233 		chan->seg_v = old_head;
1234 
1235 		tail_segment->hw.next_desc = chan->seg_v->phys;
1236 		head_desc->async_tx.phys = new_head->phys;
1237 	}
1238 
1239 	reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
1240 
1241 	if (chan->desc_pendingcount <= XILINX_DMA_COALESCE_MAX) {
1242 		reg &= ~XILINX_DMA_CR_COALESCE_MAX;
1243 		reg |= chan->desc_pendingcount <<
1244 				  XILINX_DMA_CR_COALESCE_SHIFT;
1245 		dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
1246 	}
1247 
1248 	if (chan->has_sg && !chan->xdev->mcdma)
1249 		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
1250 			     head_desc->async_tx.phys);
1251 
1252 	if (chan->has_sg && chan->xdev->mcdma) {
1253 		if (chan->direction == DMA_MEM_TO_DEV) {
1254 			dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
1255 				       head_desc->async_tx.phys);
1256 		} else {
1257 			if (!chan->tdest) {
1258 				dma_ctrl_write(chan, XILINX_DMA_REG_CURDESC,
1259 				       head_desc->async_tx.phys);
1260 			} else {
1261 				dma_ctrl_write(chan,
1262 					XILINX_DMA_MCRX_CDESC(chan->tdest),
1263 				       head_desc->async_tx.phys);
1264 			}
1265 		}
1266 	}
1267 
1268 	xilinx_dma_start(chan);
1269 
1270 	if (chan->err)
1271 		return;
1272 
1273 	/* Start the transfer */
1274 	if (chan->has_sg && !chan->xdev->mcdma) {
1275 		if (chan->cyclic)
1276 			xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
1277 				     chan->cyclic_seg_v->phys);
1278 		else
1279 			xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
1280 				     tail_segment->phys);
1281 	} else if (chan->has_sg && chan->xdev->mcdma) {
1282 		if (chan->direction == DMA_MEM_TO_DEV) {
1283 			dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
1284 			       tail_segment->phys);
1285 		} else {
1286 			if (!chan->tdest) {
1287 				dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC,
1288 					       tail_segment->phys);
1289 			} else {
1290 				dma_ctrl_write(chan,
1291 					XILINX_DMA_MCRX_TDESC(chan->tdest),
1292 					tail_segment->phys);
1293 			}
1294 		}
1295 	} else {
1296 		struct xilinx_axidma_tx_segment *segment;
1297 		struct xilinx_axidma_desc_hw *hw;
1298 
1299 		segment = list_first_entry(&head_desc->segments,
1300 					   struct xilinx_axidma_tx_segment,
1301 					   node);
1302 		hw = &segment->hw;
1303 
1304 		xilinx_write(chan, XILINX_DMA_REG_SRCDSTADDR, hw->buf_addr);
1305 
1306 		/* Start the transfer */
1307 		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
1308 			       hw->control & XILINX_DMA_MAX_TRANS_LEN);
1309 	}
1310 
1311 	list_splice_tail_init(&chan->pending_list, &chan->active_list);
1312 	chan->desc_pendingcount = 0;
1313 }
1314 
1315 /**
1316  * xilinx_dma_issue_pending - Issue pending transactions
1317  * @dchan: DMA channel
1318  */
1319 static void xilinx_dma_issue_pending(struct dma_chan *dchan)
1320 {
1321 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1322 	unsigned long flags;
1323 
1324 	spin_lock_irqsave(&chan->lock, flags);
1325 	chan->start_transfer(chan);
1326 	spin_unlock_irqrestore(&chan->lock, flags);
1327 }
1328 
1329 /**
1330  * xilinx_dma_complete_descriptor - Mark the active descriptor as complete
1331  * @chan : xilinx DMA channel
1332  *
1333  * CONTEXT: hardirq
1334  */
1335 static void xilinx_dma_complete_descriptor(struct xilinx_dma_chan *chan)
1336 {
1337 	struct xilinx_dma_tx_descriptor *desc, *next;
1338 
1339 	/* This function was invoked with lock held */
1340 	if (list_empty(&chan->active_list))
1341 		return;
1342 
1343 	list_for_each_entry_safe(desc, next, &chan->active_list, node) {
1344 		list_del(&desc->node);
1345 		if (!desc->cyclic)
1346 			dma_cookie_complete(&desc->async_tx);
1347 		list_add_tail(&desc->node, &chan->done_list);
1348 	}
1349 }
1350 
1351 /**
1352  * xilinx_dma_reset - Reset DMA channel
1353  * @chan: Driver specific DMA channel
1354  *
1355  * Return: '0' on success and failure value on error
1356  */
1357 static int xilinx_dma_reset(struct xilinx_dma_chan *chan)
1358 {
1359 	int err;
1360 	u32 tmp;
1361 
1362 	dma_ctrl_set(chan, XILINX_DMA_REG_DMACR, XILINX_DMA_DMACR_RESET);
1363 
1364 	/* Wait for the hardware to finish reset */
1365 	err = xilinx_dma_poll_timeout(chan, XILINX_DMA_REG_DMACR, tmp,
1366 				      !(tmp & XILINX_DMA_DMACR_RESET), 0,
1367 				      XILINX_DMA_LOOP_COUNT);
1368 
1369 	if (err) {
1370 		dev_err(chan->dev, "reset timeout, cr %x, sr %x\n",
1371 			dma_ctrl_read(chan, XILINX_DMA_REG_DMACR),
1372 			dma_ctrl_read(chan, XILINX_DMA_REG_DMASR));
1373 		return -ETIMEDOUT;
1374 	}
1375 
1376 	chan->err = false;
1377 
1378 	return err;
1379 }
1380 
1381 /**
1382  * xilinx_dma_chan_reset - Reset DMA channel and enable interrupts
1383  * @chan: Driver specific DMA channel
1384  *
1385  * Return: '0' on success and failure value on error
1386  */
1387 static int xilinx_dma_chan_reset(struct xilinx_dma_chan *chan)
1388 {
1389 	int err;
1390 
1391 	/* Reset VDMA */
1392 	err = xilinx_dma_reset(chan);
1393 	if (err)
1394 		return err;
1395 
1396 	/* Enable interrupts */
1397 	dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
1398 		      XILINX_DMA_DMAXR_ALL_IRQ_MASK);
1399 
1400 	return 0;
1401 }
1402 
1403 /**
1404  * xilinx_dma_irq_handler - DMA Interrupt handler
1405  * @irq: IRQ number
1406  * @data: Pointer to the Xilinx DMA channel structure
1407  *
1408  * Return: IRQ_HANDLED/IRQ_NONE
1409  */
1410 static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
1411 {
1412 	struct xilinx_dma_chan *chan = data;
1413 	u32 status;
1414 
1415 	/* Read the status and ack the interrupts. */
1416 	status = dma_ctrl_read(chan, XILINX_DMA_REG_DMASR);
1417 	if (!(status & XILINX_DMA_DMAXR_ALL_IRQ_MASK))
1418 		return IRQ_NONE;
1419 
1420 	dma_ctrl_write(chan, XILINX_DMA_REG_DMASR,
1421 			status & XILINX_DMA_DMAXR_ALL_IRQ_MASK);
1422 
1423 	if (status & XILINX_DMA_DMASR_ERR_IRQ) {
1424 		/*
1425 		 * An error occurred. If C_FLUSH_ON_FSYNC is enabled and the
1426 		 * error is recoverable, ignore it. Otherwise flag the error.
1427 		 *
1428 		 * Only recoverable errors can be cleared in the DMASR register,
1429 		 * make sure not to write to other error bits to 1.
1430 		 */
1431 		u32 errors = status & XILINX_DMA_DMASR_ALL_ERR_MASK;
1432 
1433 		dma_ctrl_write(chan, XILINX_DMA_REG_DMASR,
1434 				errors & XILINX_DMA_DMASR_ERR_RECOVER_MASK);
1435 
1436 		if (!chan->flush_on_fsync ||
1437 		    (errors & ~XILINX_DMA_DMASR_ERR_RECOVER_MASK)) {
1438 			dev_err(chan->dev,
1439 				"Channel %p has errors %x, cdr %x tdr %x\n",
1440 				chan, errors,
1441 				dma_ctrl_read(chan, XILINX_DMA_REG_CURDESC),
1442 				dma_ctrl_read(chan, XILINX_DMA_REG_TAILDESC));
1443 			chan->err = true;
1444 		}
1445 	}
1446 
1447 	if (status & XILINX_DMA_DMASR_DLY_CNT_IRQ) {
1448 		/*
1449 		 * Device takes too long to do the transfer when user requires
1450 		 * responsiveness.
1451 		 */
1452 		dev_dbg(chan->dev, "Inter-packet latency too long\n");
1453 	}
1454 
1455 	if (status & XILINX_DMA_DMASR_FRM_CNT_IRQ) {
1456 		spin_lock(&chan->lock);
1457 		xilinx_dma_complete_descriptor(chan);
1458 		chan->start_transfer(chan);
1459 		spin_unlock(&chan->lock);
1460 	}
1461 
1462 	tasklet_schedule(&chan->tasklet);
1463 	return IRQ_HANDLED;
1464 }
1465 
1466 /**
1467  * append_desc_queue - Queuing descriptor
1468  * @chan: Driver specific dma channel
1469  * @desc: dma transaction descriptor
1470  */
1471 static void append_desc_queue(struct xilinx_dma_chan *chan,
1472 			      struct xilinx_dma_tx_descriptor *desc)
1473 {
1474 	struct xilinx_vdma_tx_segment *tail_segment;
1475 	struct xilinx_dma_tx_descriptor *tail_desc;
1476 	struct xilinx_axidma_tx_segment *axidma_tail_segment;
1477 	struct xilinx_cdma_tx_segment *cdma_tail_segment;
1478 
1479 	if (list_empty(&chan->pending_list))
1480 		goto append;
1481 
1482 	/*
1483 	 * Add the hardware descriptor to the chain of hardware descriptors
1484 	 * that already exists in memory.
1485 	 */
1486 	tail_desc = list_last_entry(&chan->pending_list,
1487 				    struct xilinx_dma_tx_descriptor, node);
1488 	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
1489 		tail_segment = list_last_entry(&tail_desc->segments,
1490 					       struct xilinx_vdma_tx_segment,
1491 					       node);
1492 		tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
1493 	} else if (chan->xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
1494 		cdma_tail_segment = list_last_entry(&tail_desc->segments,
1495 						struct xilinx_cdma_tx_segment,
1496 						node);
1497 		cdma_tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
1498 	} else {
1499 		axidma_tail_segment = list_last_entry(&tail_desc->segments,
1500 					       struct xilinx_axidma_tx_segment,
1501 					       node);
1502 		axidma_tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
1503 	}
1504 
1505 	/*
1506 	 * Add the software descriptor and all children to the list
1507 	 * of pending transactions
1508 	 */
1509 append:
1510 	list_add_tail(&desc->node, &chan->pending_list);
1511 	chan->desc_pendingcount++;
1512 
1513 	if (chan->has_sg && (chan->xdev->dma_config->dmatype == XDMA_TYPE_VDMA)
1514 	    && unlikely(chan->desc_pendingcount > chan->num_frms)) {
1515 		dev_dbg(chan->dev, "desc pendingcount is too high\n");
1516 		chan->desc_pendingcount = chan->num_frms;
1517 	}
1518 }
1519 
1520 /**
1521  * xilinx_dma_tx_submit - Submit DMA transaction
1522  * @tx: Async transaction descriptor
1523  *
1524  * Return: cookie value on success and failure value on error
1525  */
1526 static dma_cookie_t xilinx_dma_tx_submit(struct dma_async_tx_descriptor *tx)
1527 {
1528 	struct xilinx_dma_tx_descriptor *desc = to_dma_tx_descriptor(tx);
1529 	struct xilinx_dma_chan *chan = to_xilinx_chan(tx->chan);
1530 	dma_cookie_t cookie;
1531 	unsigned long flags;
1532 	int err;
1533 
1534 	if (chan->cyclic) {
1535 		xilinx_dma_free_tx_descriptor(chan, desc);
1536 		return -EBUSY;
1537 	}
1538 
1539 	if (chan->err) {
1540 		/*
1541 		 * If reset fails, need to hard reset the system.
1542 		 * Channel is no longer functional
1543 		 */
1544 		err = xilinx_dma_chan_reset(chan);
1545 		if (err < 0)
1546 			return err;
1547 	}
1548 
1549 	spin_lock_irqsave(&chan->lock, flags);
1550 
1551 	cookie = dma_cookie_assign(tx);
1552 
1553 	/* Put this transaction onto the tail of the pending queue */
1554 	append_desc_queue(chan, desc);
1555 
1556 	if (desc->cyclic)
1557 		chan->cyclic = true;
1558 
1559 	spin_unlock_irqrestore(&chan->lock, flags);
1560 
1561 	return cookie;
1562 }
1563 
1564 /**
1565  * xilinx_vdma_dma_prep_interleaved - prepare a descriptor for a
1566  *	DMA_SLAVE transaction
1567  * @dchan: DMA channel
1568  * @xt: Interleaved template pointer
1569  * @flags: transfer ack flags
1570  *
1571  * Return: Async transaction descriptor on success and NULL on failure
1572  */
1573 static struct dma_async_tx_descriptor *
1574 xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
1575 				 struct dma_interleaved_template *xt,
1576 				 unsigned long flags)
1577 {
1578 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1579 	struct xilinx_dma_tx_descriptor *desc;
1580 	struct xilinx_vdma_tx_segment *segment, *prev = NULL;
1581 	struct xilinx_vdma_desc_hw *hw;
1582 
1583 	if (!is_slave_direction(xt->dir))
1584 		return NULL;
1585 
1586 	if (!xt->numf || !xt->sgl[0].size)
1587 		return NULL;
1588 
1589 	if (xt->frame_size != 1)
1590 		return NULL;
1591 
1592 	/* Allocate a transaction descriptor. */
1593 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1594 	if (!desc)
1595 		return NULL;
1596 
1597 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1598 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1599 	async_tx_ack(&desc->async_tx);
1600 
1601 	/* Allocate the link descriptor from DMA pool */
1602 	segment = xilinx_vdma_alloc_tx_segment(chan);
1603 	if (!segment)
1604 		goto error;
1605 
1606 	/* Fill in the hardware descriptor */
1607 	hw = &segment->hw;
1608 	hw->vsize = xt->numf;
1609 	hw->hsize = xt->sgl[0].size;
1610 	hw->stride = (xt->sgl[0].icg + xt->sgl[0].size) <<
1611 			XILINX_DMA_FRMDLY_STRIDE_STRIDE_SHIFT;
1612 	hw->stride |= chan->config.frm_dly <<
1613 			XILINX_DMA_FRMDLY_STRIDE_FRMDLY_SHIFT;
1614 
1615 	if (xt->dir != DMA_MEM_TO_DEV) {
1616 		if (chan->ext_addr) {
1617 			hw->buf_addr = lower_32_bits(xt->dst_start);
1618 			hw->buf_addr_msb = upper_32_bits(xt->dst_start);
1619 		} else {
1620 			hw->buf_addr = xt->dst_start;
1621 		}
1622 	} else {
1623 		if (chan->ext_addr) {
1624 			hw->buf_addr = lower_32_bits(xt->src_start);
1625 			hw->buf_addr_msb = upper_32_bits(xt->src_start);
1626 		} else {
1627 			hw->buf_addr = xt->src_start;
1628 		}
1629 	}
1630 
1631 	/* Insert the segment into the descriptor segments list. */
1632 	list_add_tail(&segment->node, &desc->segments);
1633 
1634 	prev = segment;
1635 
1636 	/* Link the last hardware descriptor with the first. */
1637 	segment = list_first_entry(&desc->segments,
1638 				   struct xilinx_vdma_tx_segment, node);
1639 	desc->async_tx.phys = segment->phys;
1640 
1641 	return &desc->async_tx;
1642 
1643 error:
1644 	xilinx_dma_free_tx_descriptor(chan, desc);
1645 	return NULL;
1646 }
1647 
1648 /**
1649  * xilinx_cdma_prep_memcpy - prepare descriptors for a memcpy transaction
1650  * @dchan: DMA channel
1651  * @dma_dst: destination address
1652  * @dma_src: source address
1653  * @len: transfer length
1654  * @flags: transfer ack flags
1655  *
1656  * Return: Async transaction descriptor on success and NULL on failure
1657  */
1658 static struct dma_async_tx_descriptor *
1659 xilinx_cdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
1660 			dma_addr_t dma_src, size_t len, unsigned long flags)
1661 {
1662 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1663 	struct xilinx_dma_tx_descriptor *desc;
1664 	struct xilinx_cdma_tx_segment *segment;
1665 	struct xilinx_cdma_desc_hw *hw;
1666 
1667 	if (!len || len > XILINX_DMA_MAX_TRANS_LEN)
1668 		return NULL;
1669 
1670 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1671 	if (!desc)
1672 		return NULL;
1673 
1674 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1675 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1676 
1677 	/* Allocate the link descriptor from DMA pool */
1678 	segment = xilinx_cdma_alloc_tx_segment(chan);
1679 	if (!segment)
1680 		goto error;
1681 
1682 	hw = &segment->hw;
1683 	hw->control = len;
1684 	hw->src_addr = dma_src;
1685 	hw->dest_addr = dma_dst;
1686 	if (chan->ext_addr) {
1687 		hw->src_addr_msb = upper_32_bits(dma_src);
1688 		hw->dest_addr_msb = upper_32_bits(dma_dst);
1689 	}
1690 
1691 	/* Insert the segment into the descriptor segments list. */
1692 	list_add_tail(&segment->node, &desc->segments);
1693 
1694 	desc->async_tx.phys = segment->phys;
1695 	hw->next_desc = segment->phys;
1696 
1697 	return &desc->async_tx;
1698 
1699 error:
1700 	xilinx_dma_free_tx_descriptor(chan, desc);
1701 	return NULL;
1702 }
1703 
1704 /**
1705  * xilinx_dma_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
1706  * @dchan: DMA channel
1707  * @sgl: scatterlist to transfer to/from
1708  * @sg_len: number of entries in @scatterlist
1709  * @direction: DMA direction
1710  * @flags: transfer ack flags
1711  * @context: APP words of the descriptor
1712  *
1713  * Return: Async transaction descriptor on success and NULL on failure
1714  */
1715 static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
1716 	struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
1717 	enum dma_transfer_direction direction, unsigned long flags,
1718 	void *context)
1719 {
1720 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1721 	struct xilinx_dma_tx_descriptor *desc;
1722 	struct xilinx_axidma_tx_segment *segment = NULL, *prev = NULL;
1723 	u32 *app_w = (u32 *)context;
1724 	struct scatterlist *sg;
1725 	size_t copy;
1726 	size_t sg_used;
1727 	unsigned int i;
1728 
1729 	if (!is_slave_direction(direction))
1730 		return NULL;
1731 
1732 	/* Allocate a transaction descriptor. */
1733 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1734 	if (!desc)
1735 		return NULL;
1736 
1737 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1738 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1739 
1740 	/* Build transactions using information in the scatter gather list */
1741 	for_each_sg(sgl, sg, sg_len, i) {
1742 		sg_used = 0;
1743 
1744 		/* Loop until the entire scatterlist entry is used */
1745 		while (sg_used < sg_dma_len(sg)) {
1746 			struct xilinx_axidma_desc_hw *hw;
1747 
1748 			/* Get a free segment */
1749 			segment = xilinx_axidma_alloc_tx_segment(chan);
1750 			if (!segment)
1751 				goto error;
1752 
1753 			/*
1754 			 * Calculate the maximum number of bytes to transfer,
1755 			 * making sure it is less than the hw limit
1756 			 */
1757 			copy = min_t(size_t, sg_dma_len(sg) - sg_used,
1758 				     XILINX_DMA_MAX_TRANS_LEN);
1759 			hw = &segment->hw;
1760 
1761 			/* Fill in the descriptor */
1762 			xilinx_axidma_buf(chan, hw, sg_dma_address(sg),
1763 					  sg_used, 0);
1764 
1765 			hw->control = copy;
1766 
1767 			if (chan->direction == DMA_MEM_TO_DEV) {
1768 				if (app_w)
1769 					memcpy(hw->app, app_w, sizeof(u32) *
1770 					       XILINX_DMA_NUM_APP_WORDS);
1771 			}
1772 
1773 			if (prev)
1774 				prev->hw.next_desc = segment->phys;
1775 
1776 			prev = segment;
1777 			sg_used += copy;
1778 
1779 			/*
1780 			 * Insert the segment into the descriptor segments
1781 			 * list.
1782 			 */
1783 			list_add_tail(&segment->node, &desc->segments);
1784 		}
1785 	}
1786 
1787 	segment = list_first_entry(&desc->segments,
1788 				   struct xilinx_axidma_tx_segment, node);
1789 	desc->async_tx.phys = segment->phys;
1790 	prev->hw.next_desc = segment->phys;
1791 
1792 	/* For the last DMA_MEM_TO_DEV transfer, set EOP */
1793 	if (chan->direction == DMA_MEM_TO_DEV) {
1794 		segment->hw.control |= XILINX_DMA_BD_SOP;
1795 		segment = list_last_entry(&desc->segments,
1796 					  struct xilinx_axidma_tx_segment,
1797 					  node);
1798 		segment->hw.control |= XILINX_DMA_BD_EOP;
1799 	}
1800 
1801 	return &desc->async_tx;
1802 
1803 error:
1804 	xilinx_dma_free_tx_descriptor(chan, desc);
1805 	return NULL;
1806 }
1807 
1808 /**
1809  * xilinx_dma_prep_dma_cyclic - prepare descriptors for a DMA_SLAVE transaction
1810  * @chan: DMA channel
1811  * @sgl: scatterlist to transfer to/from
1812  * @sg_len: number of entries in @scatterlist
1813  * @direction: DMA direction
1814  * @flags: transfer ack flags
1815  */
1816 static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
1817 	struct dma_chan *dchan, dma_addr_t buf_addr, size_t buf_len,
1818 	size_t period_len, enum dma_transfer_direction direction,
1819 	unsigned long flags)
1820 {
1821 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1822 	struct xilinx_dma_tx_descriptor *desc;
1823 	struct xilinx_axidma_tx_segment *segment, *head_segment, *prev = NULL;
1824 	size_t copy, sg_used;
1825 	unsigned int num_periods;
1826 	int i;
1827 	u32 reg;
1828 
1829 	if (!period_len)
1830 		return NULL;
1831 
1832 	num_periods = buf_len / period_len;
1833 
1834 	if (!num_periods)
1835 		return NULL;
1836 
1837 	if (!is_slave_direction(direction))
1838 		return NULL;
1839 
1840 	/* Allocate a transaction descriptor. */
1841 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1842 	if (!desc)
1843 		return NULL;
1844 
1845 	chan->direction = direction;
1846 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1847 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1848 
1849 	for (i = 0; i < num_periods; ++i) {
1850 		sg_used = 0;
1851 
1852 		while (sg_used < period_len) {
1853 			struct xilinx_axidma_desc_hw *hw;
1854 
1855 			/* Get a free segment */
1856 			segment = xilinx_axidma_alloc_tx_segment(chan);
1857 			if (!segment)
1858 				goto error;
1859 
1860 			/*
1861 			 * Calculate the maximum number of bytes to transfer,
1862 			 * making sure it is less than the hw limit
1863 			 */
1864 			copy = min_t(size_t, period_len - sg_used,
1865 				     XILINX_DMA_MAX_TRANS_LEN);
1866 			hw = &segment->hw;
1867 			xilinx_axidma_buf(chan, hw, buf_addr, sg_used,
1868 					  period_len * i);
1869 			hw->control = copy;
1870 
1871 			if (prev)
1872 				prev->hw.next_desc = segment->phys;
1873 
1874 			prev = segment;
1875 			sg_used += copy;
1876 
1877 			/*
1878 			 * Insert the segment into the descriptor segments
1879 			 * list.
1880 			 */
1881 			list_add_tail(&segment->node, &desc->segments);
1882 		}
1883 	}
1884 
1885 	head_segment = list_first_entry(&desc->segments,
1886 				   struct xilinx_axidma_tx_segment, node);
1887 	desc->async_tx.phys = head_segment->phys;
1888 
1889 	desc->cyclic = true;
1890 	reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
1891 	reg |= XILINX_DMA_CR_CYCLIC_BD_EN_MASK;
1892 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
1893 
1894 	segment = list_last_entry(&desc->segments,
1895 				  struct xilinx_axidma_tx_segment,
1896 				  node);
1897 	segment->hw.next_desc = (u32) head_segment->phys;
1898 
1899 	/* For the last DMA_MEM_TO_DEV transfer, set EOP */
1900 	if (direction == DMA_MEM_TO_DEV) {
1901 		head_segment->hw.control |= XILINX_DMA_BD_SOP;
1902 		segment->hw.control |= XILINX_DMA_BD_EOP;
1903 	}
1904 
1905 	return &desc->async_tx;
1906 
1907 error:
1908 	xilinx_dma_free_tx_descriptor(chan, desc);
1909 	return NULL;
1910 }
1911 
1912 /**
1913  * xilinx_dma_prep_interleaved - prepare a descriptor for a
1914  *	DMA_SLAVE transaction
1915  * @dchan: DMA channel
1916  * @xt: Interleaved template pointer
1917  * @flags: transfer ack flags
1918  *
1919  * Return: Async transaction descriptor on success and NULL on failure
1920  */
1921 static struct dma_async_tx_descriptor *
1922 xilinx_dma_prep_interleaved(struct dma_chan *dchan,
1923 				 struct dma_interleaved_template *xt,
1924 				 unsigned long flags)
1925 {
1926 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
1927 	struct xilinx_dma_tx_descriptor *desc;
1928 	struct xilinx_axidma_tx_segment *segment;
1929 	struct xilinx_axidma_desc_hw *hw;
1930 
1931 	if (!is_slave_direction(xt->dir))
1932 		return NULL;
1933 
1934 	if (!xt->numf || !xt->sgl[0].size)
1935 		return NULL;
1936 
1937 	if (xt->frame_size != 1)
1938 		return NULL;
1939 
1940 	/* Allocate a transaction descriptor. */
1941 	desc = xilinx_dma_alloc_tx_descriptor(chan);
1942 	if (!desc)
1943 		return NULL;
1944 
1945 	chan->direction = xt->dir;
1946 	dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
1947 	desc->async_tx.tx_submit = xilinx_dma_tx_submit;
1948 
1949 	/* Get a free segment */
1950 	segment = xilinx_axidma_alloc_tx_segment(chan);
1951 	if (!segment)
1952 		goto error;
1953 
1954 	hw = &segment->hw;
1955 
1956 	/* Fill in the descriptor */
1957 	if (xt->dir != DMA_MEM_TO_DEV)
1958 		hw->buf_addr = xt->dst_start;
1959 	else
1960 		hw->buf_addr = xt->src_start;
1961 
1962 	hw->mcdma_control = chan->tdest & XILINX_DMA_BD_TDEST_MASK;
1963 	hw->vsize_stride = (xt->numf << XILINX_DMA_BD_VSIZE_SHIFT) &
1964 			    XILINX_DMA_BD_VSIZE_MASK;
1965 	hw->vsize_stride |= (xt->sgl[0].icg + xt->sgl[0].size) &
1966 			    XILINX_DMA_BD_STRIDE_MASK;
1967 	hw->control = xt->sgl[0].size & XILINX_DMA_BD_HSIZE_MASK;
1968 
1969 	/*
1970 	 * Insert the segment into the descriptor segments
1971 	 * list.
1972 	 */
1973 	list_add_tail(&segment->node, &desc->segments);
1974 
1975 
1976 	segment = list_first_entry(&desc->segments,
1977 				   struct xilinx_axidma_tx_segment, node);
1978 	desc->async_tx.phys = segment->phys;
1979 
1980 	/* For the last DMA_MEM_TO_DEV transfer, set EOP */
1981 	if (xt->dir == DMA_MEM_TO_DEV) {
1982 		segment->hw.control |= XILINX_DMA_BD_SOP;
1983 		segment = list_last_entry(&desc->segments,
1984 					  struct xilinx_axidma_tx_segment,
1985 					  node);
1986 		segment->hw.control |= XILINX_DMA_BD_EOP;
1987 	}
1988 
1989 	return &desc->async_tx;
1990 
1991 error:
1992 	xilinx_dma_free_tx_descriptor(chan, desc);
1993 	return NULL;
1994 }
1995 
1996 /**
1997  * xilinx_dma_terminate_all - Halt the channel and free descriptors
1998  * @chan: Driver specific DMA Channel pointer
1999  */
2000 static int xilinx_dma_terminate_all(struct dma_chan *dchan)
2001 {
2002 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
2003 	u32 reg;
2004 	int err;
2005 
2006 	if (chan->cyclic)
2007 		xilinx_dma_chan_reset(chan);
2008 
2009 	err = chan->stop_transfer(chan);
2010 	if (err) {
2011 		dev_err(chan->dev, "Cannot stop channel %p: %x\n",
2012 			chan, dma_ctrl_read(chan, XILINX_DMA_REG_DMASR));
2013 		chan->err = true;
2014 	}
2015 
2016 	/* Remove and free all of the descriptors in the lists */
2017 	xilinx_dma_free_descriptors(chan);
2018 
2019 	if (chan->cyclic) {
2020 		reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
2021 		reg &= ~XILINX_DMA_CR_CYCLIC_BD_EN_MASK;
2022 		dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg);
2023 		chan->cyclic = false;
2024 	}
2025 
2026 	return 0;
2027 }
2028 
2029 /**
2030  * xilinx_dma_channel_set_config - Configure VDMA channel
2031  * Run-time configuration for Axi VDMA, supports:
2032  * . halt the channel
2033  * . configure interrupt coalescing and inter-packet delay threshold
2034  * . start/stop parking
2035  * . enable genlock
2036  *
2037  * @dchan: DMA channel
2038  * @cfg: VDMA device configuration pointer
2039  *
2040  * Return: '0' on success and failure value on error
2041  */
2042 int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
2043 					struct xilinx_vdma_config *cfg)
2044 {
2045 	struct xilinx_dma_chan *chan = to_xilinx_chan(dchan);
2046 	u32 dmacr;
2047 
2048 	if (cfg->reset)
2049 		return xilinx_dma_chan_reset(chan);
2050 
2051 	dmacr = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR);
2052 
2053 	chan->config.frm_dly = cfg->frm_dly;
2054 	chan->config.park = cfg->park;
2055 
2056 	/* genlock settings */
2057 	chan->config.gen_lock = cfg->gen_lock;
2058 	chan->config.master = cfg->master;
2059 
2060 	if (cfg->gen_lock && chan->genlock) {
2061 		dmacr |= XILINX_DMA_DMACR_GENLOCK_EN;
2062 		dmacr |= cfg->master << XILINX_DMA_DMACR_MASTER_SHIFT;
2063 	}
2064 
2065 	chan->config.frm_cnt_en = cfg->frm_cnt_en;
2066 	if (cfg->park)
2067 		chan->config.park_frm = cfg->park_frm;
2068 	else
2069 		chan->config.park_frm = -1;
2070 
2071 	chan->config.coalesc = cfg->coalesc;
2072 	chan->config.delay = cfg->delay;
2073 
2074 	if (cfg->coalesc <= XILINX_DMA_DMACR_FRAME_COUNT_MAX) {
2075 		dmacr |= cfg->coalesc << XILINX_DMA_DMACR_FRAME_COUNT_SHIFT;
2076 		chan->config.coalesc = cfg->coalesc;
2077 	}
2078 
2079 	if (cfg->delay <= XILINX_DMA_DMACR_DELAY_MAX) {
2080 		dmacr |= cfg->delay << XILINX_DMA_DMACR_DELAY_SHIFT;
2081 		chan->config.delay = cfg->delay;
2082 	}
2083 
2084 	/* FSync Source selection */
2085 	dmacr &= ~XILINX_DMA_DMACR_FSYNCSRC_MASK;
2086 	dmacr |= cfg->ext_fsync << XILINX_DMA_DMACR_FSYNCSRC_SHIFT;
2087 
2088 	dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, dmacr);
2089 
2090 	return 0;
2091 }
2092 EXPORT_SYMBOL(xilinx_vdma_channel_set_config);
2093 
2094 /* -----------------------------------------------------------------------------
2095  * Probe and remove
2096  */
2097 
2098 /**
2099  * xilinx_dma_chan_remove - Per Channel remove function
2100  * @chan: Driver specific DMA channel
2101  */
2102 static void xilinx_dma_chan_remove(struct xilinx_dma_chan *chan)
2103 {
2104 	/* Disable all interrupts */
2105 	dma_ctrl_clr(chan, XILINX_DMA_REG_DMACR,
2106 		      XILINX_DMA_DMAXR_ALL_IRQ_MASK);
2107 
2108 	if (chan->irq > 0)
2109 		free_irq(chan->irq, chan);
2110 
2111 	tasklet_kill(&chan->tasklet);
2112 
2113 	list_del(&chan->common.device_node);
2114 }
2115 
2116 static int axidma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
2117 			    struct clk **tx_clk, struct clk **rx_clk,
2118 			    struct clk **sg_clk, struct clk **tmp_clk)
2119 {
2120 	int err;
2121 
2122 	*tmp_clk = NULL;
2123 
2124 	*axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
2125 	if (IS_ERR(*axi_clk)) {
2126 		err = PTR_ERR(*axi_clk);
2127 		dev_err(&pdev->dev, "failed to get axi_aclk (%d)\n", err);
2128 		return err;
2129 	}
2130 
2131 	*tx_clk = devm_clk_get(&pdev->dev, "m_axi_mm2s_aclk");
2132 	if (IS_ERR(*tx_clk))
2133 		*tx_clk = NULL;
2134 
2135 	*rx_clk = devm_clk_get(&pdev->dev, "m_axi_s2mm_aclk");
2136 	if (IS_ERR(*rx_clk))
2137 		*rx_clk = NULL;
2138 
2139 	*sg_clk = devm_clk_get(&pdev->dev, "m_axi_sg_aclk");
2140 	if (IS_ERR(*sg_clk))
2141 		*sg_clk = NULL;
2142 
2143 	err = clk_prepare_enable(*axi_clk);
2144 	if (err) {
2145 		dev_err(&pdev->dev, "failed to enable axi_clk (%d)\n", err);
2146 		return err;
2147 	}
2148 
2149 	err = clk_prepare_enable(*tx_clk);
2150 	if (err) {
2151 		dev_err(&pdev->dev, "failed to enable tx_clk (%d)\n", err);
2152 		goto err_disable_axiclk;
2153 	}
2154 
2155 	err = clk_prepare_enable(*rx_clk);
2156 	if (err) {
2157 		dev_err(&pdev->dev, "failed to enable rx_clk (%d)\n", err);
2158 		goto err_disable_txclk;
2159 	}
2160 
2161 	err = clk_prepare_enable(*sg_clk);
2162 	if (err) {
2163 		dev_err(&pdev->dev, "failed to enable sg_clk (%d)\n", err);
2164 		goto err_disable_rxclk;
2165 	}
2166 
2167 	return 0;
2168 
2169 err_disable_rxclk:
2170 	clk_disable_unprepare(*rx_clk);
2171 err_disable_txclk:
2172 	clk_disable_unprepare(*tx_clk);
2173 err_disable_axiclk:
2174 	clk_disable_unprepare(*axi_clk);
2175 
2176 	return err;
2177 }
2178 
2179 static int axicdma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
2180 			    struct clk **dev_clk, struct clk **tmp_clk,
2181 			    struct clk **tmp1_clk, struct clk **tmp2_clk)
2182 {
2183 	int err;
2184 
2185 	*tmp_clk = NULL;
2186 	*tmp1_clk = NULL;
2187 	*tmp2_clk = NULL;
2188 
2189 	*axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
2190 	if (IS_ERR(*axi_clk)) {
2191 		err = PTR_ERR(*axi_clk);
2192 		dev_err(&pdev->dev, "failed to get axi_clk (%d)\n", err);
2193 		return err;
2194 	}
2195 
2196 	*dev_clk = devm_clk_get(&pdev->dev, "m_axi_aclk");
2197 	if (IS_ERR(*dev_clk)) {
2198 		err = PTR_ERR(*dev_clk);
2199 		dev_err(&pdev->dev, "failed to get dev_clk (%d)\n", err);
2200 		return err;
2201 	}
2202 
2203 	err = clk_prepare_enable(*axi_clk);
2204 	if (err) {
2205 		dev_err(&pdev->dev, "failed to enable axi_clk (%d)\n", err);
2206 		return err;
2207 	}
2208 
2209 	err = clk_prepare_enable(*dev_clk);
2210 	if (err) {
2211 		dev_err(&pdev->dev, "failed to enable dev_clk (%d)\n", err);
2212 		goto err_disable_axiclk;
2213 	}
2214 
2215 	return 0;
2216 
2217 err_disable_axiclk:
2218 	clk_disable_unprepare(*axi_clk);
2219 
2220 	return err;
2221 }
2222 
2223 static int axivdma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
2224 			    struct clk **tx_clk, struct clk **txs_clk,
2225 			    struct clk **rx_clk, struct clk **rxs_clk)
2226 {
2227 	int err;
2228 
2229 	*axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
2230 	if (IS_ERR(*axi_clk)) {
2231 		err = PTR_ERR(*axi_clk);
2232 		dev_err(&pdev->dev, "failed to get axi_aclk (%d)\n", err);
2233 		return err;
2234 	}
2235 
2236 	*tx_clk = devm_clk_get(&pdev->dev, "m_axi_mm2s_aclk");
2237 	if (IS_ERR(*tx_clk))
2238 		*tx_clk = NULL;
2239 
2240 	*txs_clk = devm_clk_get(&pdev->dev, "m_axis_mm2s_aclk");
2241 	if (IS_ERR(*txs_clk))
2242 		*txs_clk = NULL;
2243 
2244 	*rx_clk = devm_clk_get(&pdev->dev, "m_axi_s2mm_aclk");
2245 	if (IS_ERR(*rx_clk))
2246 		*rx_clk = NULL;
2247 
2248 	*rxs_clk = devm_clk_get(&pdev->dev, "s_axis_s2mm_aclk");
2249 	if (IS_ERR(*rxs_clk))
2250 		*rxs_clk = NULL;
2251 
2252 	err = clk_prepare_enable(*axi_clk);
2253 	if (err) {
2254 		dev_err(&pdev->dev, "failed to enable axi_clk (%d)\n", err);
2255 		return err;
2256 	}
2257 
2258 	err = clk_prepare_enable(*tx_clk);
2259 	if (err) {
2260 		dev_err(&pdev->dev, "failed to enable tx_clk (%d)\n", err);
2261 		goto err_disable_axiclk;
2262 	}
2263 
2264 	err = clk_prepare_enable(*txs_clk);
2265 	if (err) {
2266 		dev_err(&pdev->dev, "failed to enable txs_clk (%d)\n", err);
2267 		goto err_disable_txclk;
2268 	}
2269 
2270 	err = clk_prepare_enable(*rx_clk);
2271 	if (err) {
2272 		dev_err(&pdev->dev, "failed to enable rx_clk (%d)\n", err);
2273 		goto err_disable_txsclk;
2274 	}
2275 
2276 	err = clk_prepare_enable(*rxs_clk);
2277 	if (err) {
2278 		dev_err(&pdev->dev, "failed to enable rxs_clk (%d)\n", err);
2279 		goto err_disable_rxclk;
2280 	}
2281 
2282 	return 0;
2283 
2284 err_disable_rxclk:
2285 	clk_disable_unprepare(*rx_clk);
2286 err_disable_txsclk:
2287 	clk_disable_unprepare(*txs_clk);
2288 err_disable_txclk:
2289 	clk_disable_unprepare(*tx_clk);
2290 err_disable_axiclk:
2291 	clk_disable_unprepare(*axi_clk);
2292 
2293 	return err;
2294 }
2295 
2296 static void xdma_disable_allclks(struct xilinx_dma_device *xdev)
2297 {
2298 	clk_disable_unprepare(xdev->rxs_clk);
2299 	clk_disable_unprepare(xdev->rx_clk);
2300 	clk_disable_unprepare(xdev->txs_clk);
2301 	clk_disable_unprepare(xdev->tx_clk);
2302 	clk_disable_unprepare(xdev->axi_clk);
2303 }
2304 
2305 /**
2306  * xilinx_dma_chan_probe - Per Channel Probing
2307  * It get channel features from the device tree entry and
2308  * initialize special channel handling routines
2309  *
2310  * @xdev: Driver specific device structure
2311  * @node: Device node
2312  *
2313  * Return: '0' on success and failure value on error
2314  */
2315 static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
2316 				  struct device_node *node, int chan_id)
2317 {
2318 	struct xilinx_dma_chan *chan;
2319 	bool has_dre = false;
2320 	u32 value, width;
2321 	int err;
2322 
2323 	/* Allocate and initialize the channel structure */
2324 	chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
2325 	if (!chan)
2326 		return -ENOMEM;
2327 
2328 	chan->dev = xdev->dev;
2329 	chan->xdev = xdev;
2330 	chan->has_sg = xdev->has_sg;
2331 	chan->desc_pendingcount = 0x0;
2332 	chan->ext_addr = xdev->ext_addr;
2333 
2334 	spin_lock_init(&chan->lock);
2335 	INIT_LIST_HEAD(&chan->pending_list);
2336 	INIT_LIST_HEAD(&chan->done_list);
2337 	INIT_LIST_HEAD(&chan->active_list);
2338 
2339 	/* Retrieve the channel properties from the device tree */
2340 	has_dre = of_property_read_bool(node, "xlnx,include-dre");
2341 
2342 	chan->genlock = of_property_read_bool(node, "xlnx,genlock-mode");
2343 
2344 	err = of_property_read_u32(node, "xlnx,datawidth", &value);
2345 	if (err) {
2346 		dev_err(xdev->dev, "missing xlnx,datawidth property\n");
2347 		return err;
2348 	}
2349 	width = value >> 3; /* Convert bits to bytes */
2350 
2351 	/* If data width is greater than 8 bytes, DRE is not in hw */
2352 	if (width > 8)
2353 		has_dre = false;
2354 
2355 	if (!has_dre)
2356 		xdev->common.copy_align = fls(width - 1);
2357 
2358 	if (of_device_is_compatible(node, "xlnx,axi-vdma-mm2s-channel") ||
2359 	    of_device_is_compatible(node, "xlnx,axi-dma-mm2s-channel") ||
2360 	    of_device_is_compatible(node, "xlnx,axi-cdma-channel")) {
2361 		chan->direction = DMA_MEM_TO_DEV;
2362 		chan->id = chan_id;
2363 		chan->tdest = chan_id;
2364 
2365 		chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET;
2366 		if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2367 			chan->desc_offset = XILINX_VDMA_MM2S_DESC_OFFSET;
2368 
2369 			if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
2370 			    xdev->flush_on_fsync == XILINX_DMA_FLUSH_MM2S)
2371 				chan->flush_on_fsync = true;
2372 		}
2373 	} else if (of_device_is_compatible(node,
2374 					   "xlnx,axi-vdma-s2mm-channel") ||
2375 		   of_device_is_compatible(node,
2376 					   "xlnx,axi-dma-s2mm-channel")) {
2377 		chan->direction = DMA_DEV_TO_MEM;
2378 		chan->id = chan_id;
2379 		chan->tdest = chan_id - xdev->nr_channels;
2380 
2381 		chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET;
2382 		if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2383 			chan->desc_offset = XILINX_VDMA_S2MM_DESC_OFFSET;
2384 
2385 			if (xdev->flush_on_fsync == XILINX_DMA_FLUSH_BOTH ||
2386 			    xdev->flush_on_fsync == XILINX_DMA_FLUSH_S2MM)
2387 				chan->flush_on_fsync = true;
2388 		}
2389 	} else {
2390 		dev_err(xdev->dev, "Invalid channel compatible node\n");
2391 		return -EINVAL;
2392 	}
2393 
2394 	/* Request the interrupt */
2395 	chan->irq = irq_of_parse_and_map(node, 0);
2396 	err = request_irq(chan->irq, xilinx_dma_irq_handler, IRQF_SHARED,
2397 			  "xilinx-dma-controller", chan);
2398 	if (err) {
2399 		dev_err(xdev->dev, "unable to request IRQ %d\n", chan->irq);
2400 		return err;
2401 	}
2402 
2403 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
2404 		chan->start_transfer = xilinx_dma_start_transfer;
2405 		chan->stop_transfer = xilinx_dma_stop_transfer;
2406 	} else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
2407 		chan->start_transfer = xilinx_cdma_start_transfer;
2408 		chan->stop_transfer = xilinx_cdma_stop_transfer;
2409 	} else {
2410 		chan->start_transfer = xilinx_vdma_start_transfer;
2411 		chan->stop_transfer = xilinx_dma_stop_transfer;
2412 	}
2413 
2414 	/* Initialize the tasklet */
2415 	tasklet_init(&chan->tasklet, xilinx_dma_do_tasklet,
2416 			(unsigned long)chan);
2417 
2418 	/*
2419 	 * Initialize the DMA channel and add it to the DMA engine channels
2420 	 * list.
2421 	 */
2422 	chan->common.device = &xdev->common;
2423 
2424 	list_add_tail(&chan->common.device_node, &xdev->common.channels);
2425 	xdev->chan[chan->id] = chan;
2426 
2427 	/* Reset the channel */
2428 	err = xilinx_dma_chan_reset(chan);
2429 	if (err < 0) {
2430 		dev_err(xdev->dev, "Reset channel failed\n");
2431 		return err;
2432 	}
2433 
2434 	return 0;
2435 }
2436 
2437 /**
2438  * xilinx_dma_child_probe - Per child node probe
2439  * It get number of dma-channels per child node from
2440  * device-tree and initializes all the channels.
2441  *
2442  * @xdev: Driver specific device structure
2443  * @node: Device node
2444  *
2445  * Return: 0 always.
2446  */
2447 static int xilinx_dma_child_probe(struct xilinx_dma_device *xdev,
2448 				    struct device_node *node) {
2449 	int ret, i, nr_channels = 1;
2450 
2451 	ret = of_property_read_u32(node, "dma-channels", &nr_channels);
2452 	if ((ret < 0) && xdev->mcdma)
2453 		dev_warn(xdev->dev, "missing dma-channels property\n");
2454 
2455 	for (i = 0; i < nr_channels; i++)
2456 		xilinx_dma_chan_probe(xdev, node, xdev->chan_id++);
2457 
2458 	xdev->nr_channels += nr_channels;
2459 
2460 	return 0;
2461 }
2462 
2463 /**
2464  * of_dma_xilinx_xlate - Translation function
2465  * @dma_spec: Pointer to DMA specifier as found in the device tree
2466  * @ofdma: Pointer to DMA controller data
2467  *
2468  * Return: DMA channel pointer on success and NULL on error
2469  */
2470 static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
2471 						struct of_dma *ofdma)
2472 {
2473 	struct xilinx_dma_device *xdev = ofdma->of_dma_data;
2474 	int chan_id = dma_spec->args[0];
2475 
2476 	if (chan_id >= xdev->nr_channels || !xdev->chan[chan_id])
2477 		return NULL;
2478 
2479 	return dma_get_slave_channel(&xdev->chan[chan_id]->common);
2480 }
2481 
2482 static const struct xilinx_dma_config axidma_config = {
2483 	.dmatype = XDMA_TYPE_AXIDMA,
2484 	.clk_init = axidma_clk_init,
2485 };
2486 
2487 static const struct xilinx_dma_config axicdma_config = {
2488 	.dmatype = XDMA_TYPE_CDMA,
2489 	.clk_init = axicdma_clk_init,
2490 };
2491 
2492 static const struct xilinx_dma_config axivdma_config = {
2493 	.dmatype = XDMA_TYPE_VDMA,
2494 	.clk_init = axivdma_clk_init,
2495 };
2496 
2497 static const struct of_device_id xilinx_dma_of_ids[] = {
2498 	{ .compatible = "xlnx,axi-dma-1.00.a", .data = &axidma_config },
2499 	{ .compatible = "xlnx,axi-cdma-1.00.a", .data = &axicdma_config },
2500 	{ .compatible = "xlnx,axi-vdma-1.00.a", .data = &axivdma_config },
2501 	{}
2502 };
2503 MODULE_DEVICE_TABLE(of, xilinx_dma_of_ids);
2504 
2505 /**
2506  * xilinx_dma_probe - Driver probe function
2507  * @pdev: Pointer to the platform_device structure
2508  *
2509  * Return: '0' on success and failure value on error
2510  */
2511 static int xilinx_dma_probe(struct platform_device *pdev)
2512 {
2513 	int (*clk_init)(struct platform_device *, struct clk **, struct clk **,
2514 			struct clk **, struct clk **, struct clk **)
2515 					= axivdma_clk_init;
2516 	struct device_node *node = pdev->dev.of_node;
2517 	struct xilinx_dma_device *xdev;
2518 	struct device_node *child, *np = pdev->dev.of_node;
2519 	struct resource *io;
2520 	u32 num_frames, addr_width;
2521 	int i, err;
2522 
2523 	/* Allocate and initialize the DMA engine structure */
2524 	xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
2525 	if (!xdev)
2526 		return -ENOMEM;
2527 
2528 	xdev->dev = &pdev->dev;
2529 	if (np) {
2530 		const struct of_device_id *match;
2531 
2532 		match = of_match_node(xilinx_dma_of_ids, np);
2533 		if (match && match->data) {
2534 			xdev->dma_config = match->data;
2535 			clk_init = xdev->dma_config->clk_init;
2536 		}
2537 	}
2538 
2539 	err = clk_init(pdev, &xdev->axi_clk, &xdev->tx_clk, &xdev->txs_clk,
2540 		       &xdev->rx_clk, &xdev->rxs_clk);
2541 	if (err)
2542 		return err;
2543 
2544 	/* Request and map I/O memory */
2545 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2546 	xdev->regs = devm_ioremap_resource(&pdev->dev, io);
2547 	if (IS_ERR(xdev->regs))
2548 		return PTR_ERR(xdev->regs);
2549 
2550 	/* Retrieve the DMA engine properties from the device tree */
2551 	xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
2552 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
2553 		xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");
2554 
2555 	if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2556 		err = of_property_read_u32(node, "xlnx,num-fstores",
2557 					   &num_frames);
2558 		if (err < 0) {
2559 			dev_err(xdev->dev,
2560 				"missing xlnx,num-fstores property\n");
2561 			return err;
2562 		}
2563 
2564 		err = of_property_read_u32(node, "xlnx,flush-fsync",
2565 					   &xdev->flush_on_fsync);
2566 		if (err < 0)
2567 			dev_warn(xdev->dev,
2568 				 "missing xlnx,flush-fsync property\n");
2569 	}
2570 
2571 	err = of_property_read_u32(node, "xlnx,addrwidth", &addr_width);
2572 	if (err < 0)
2573 		dev_warn(xdev->dev, "missing xlnx,addrwidth property\n");
2574 
2575 	if (addr_width > 32)
2576 		xdev->ext_addr = true;
2577 	else
2578 		xdev->ext_addr = false;
2579 
2580 	/* Set the dma mask bits */
2581 	dma_set_mask(xdev->dev, DMA_BIT_MASK(addr_width));
2582 
2583 	/* Initialize the DMA engine */
2584 	xdev->common.dev = &pdev->dev;
2585 
2586 	INIT_LIST_HEAD(&xdev->common.channels);
2587 	if (!(xdev->dma_config->dmatype == XDMA_TYPE_CDMA)) {
2588 		dma_cap_set(DMA_SLAVE, xdev->common.cap_mask);
2589 		dma_cap_set(DMA_PRIVATE, xdev->common.cap_mask);
2590 	}
2591 
2592 	xdev->common.device_alloc_chan_resources =
2593 				xilinx_dma_alloc_chan_resources;
2594 	xdev->common.device_free_chan_resources =
2595 				xilinx_dma_free_chan_resources;
2596 	xdev->common.device_terminate_all = xilinx_dma_terminate_all;
2597 	xdev->common.device_tx_status = xilinx_dma_tx_status;
2598 	xdev->common.device_issue_pending = xilinx_dma_issue_pending;
2599 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) {
2600 		dma_cap_set(DMA_CYCLIC, xdev->common.cap_mask);
2601 		xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg;
2602 		xdev->common.device_prep_dma_cyclic =
2603 					  xilinx_dma_prep_dma_cyclic;
2604 		xdev->common.device_prep_interleaved_dma =
2605 					xilinx_dma_prep_interleaved;
2606 		/* Residue calculation is supported by only AXI DMA */
2607 		xdev->common.residue_granularity =
2608 					  DMA_RESIDUE_GRANULARITY_SEGMENT;
2609 	} else if (xdev->dma_config->dmatype == XDMA_TYPE_CDMA) {
2610 		dma_cap_set(DMA_MEMCPY, xdev->common.cap_mask);
2611 		xdev->common.device_prep_dma_memcpy = xilinx_cdma_prep_memcpy;
2612 	} else {
2613 		xdev->common.device_prep_interleaved_dma =
2614 				xilinx_vdma_dma_prep_interleaved;
2615 	}
2616 
2617 	platform_set_drvdata(pdev, xdev);
2618 
2619 	/* Initialize the channels */
2620 	for_each_child_of_node(node, child) {
2621 		err = xilinx_dma_child_probe(xdev, child);
2622 		if (err < 0)
2623 			goto disable_clks;
2624 	}
2625 
2626 	if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
2627 		for (i = 0; i < xdev->nr_channels; i++)
2628 			if (xdev->chan[i])
2629 				xdev->chan[i]->num_frms = num_frames;
2630 	}
2631 
2632 	/* Register the DMA engine with the core */
2633 	dma_async_device_register(&xdev->common);
2634 
2635 	err = of_dma_controller_register(node, of_dma_xilinx_xlate,
2636 					 xdev);
2637 	if (err < 0) {
2638 		dev_err(&pdev->dev, "Unable to register DMA to DT\n");
2639 		dma_async_device_unregister(&xdev->common);
2640 		goto error;
2641 	}
2642 
2643 	dev_info(&pdev->dev, "Xilinx AXI VDMA Engine Driver Probed!!\n");
2644 
2645 	return 0;
2646 
2647 disable_clks:
2648 	xdma_disable_allclks(xdev);
2649 error:
2650 	for (i = 0; i < xdev->nr_channels; i++)
2651 		if (xdev->chan[i])
2652 			xilinx_dma_chan_remove(xdev->chan[i]);
2653 
2654 	return err;
2655 }
2656 
2657 /**
2658  * xilinx_dma_remove - Driver remove function
2659  * @pdev: Pointer to the platform_device structure
2660  *
2661  * Return: Always '0'
2662  */
2663 static int xilinx_dma_remove(struct platform_device *pdev)
2664 {
2665 	struct xilinx_dma_device *xdev = platform_get_drvdata(pdev);
2666 	int i;
2667 
2668 	of_dma_controller_free(pdev->dev.of_node);
2669 
2670 	dma_async_device_unregister(&xdev->common);
2671 
2672 	for (i = 0; i < xdev->nr_channels; i++)
2673 		if (xdev->chan[i])
2674 			xilinx_dma_chan_remove(xdev->chan[i]);
2675 
2676 	xdma_disable_allclks(xdev);
2677 
2678 	return 0;
2679 }
2680 
2681 static struct platform_driver xilinx_vdma_driver = {
2682 	.driver = {
2683 		.name = "xilinx-vdma",
2684 		.of_match_table = xilinx_dma_of_ids,
2685 	},
2686 	.probe = xilinx_dma_probe,
2687 	.remove = xilinx_dma_remove,
2688 };
2689 
2690 module_platform_driver(xilinx_vdma_driver);
2691 
2692 MODULE_AUTHOR("Xilinx, Inc.");
2693 MODULE_DESCRIPTION("Xilinx VDMA driver");
2694 MODULE_LICENSE("GPL v2");
2695