1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Xilinx ZynqMP DPDMA Engine driver
4  *
5  * Copyright (C) 2015 - 2020 Xilinx, Inc.
6  *
7  * Author: Hyun Woo Kwon <hyun.kwon@xilinx.com>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/bits.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dmapool.h>
16 #include <linux/interrupt.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_dma.h>
20 #include <linux/platform_device.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
24 #include <linux/wait.h>
25 
26 #include <dt-bindings/dma/xlnx-zynqmp-dpdma.h>
27 
28 #include "../dmaengine.h"
29 #include "../virt-dma.h"
30 
31 /* DPDMA registers */
32 #define XILINX_DPDMA_ERR_CTRL				0x000
33 #define XILINX_DPDMA_ISR				0x004
34 #define XILINX_DPDMA_IMR				0x008
35 #define XILINX_DPDMA_IEN				0x00c
36 #define XILINX_DPDMA_IDS				0x010
37 #define XILINX_DPDMA_INTR_DESC_DONE(n)			BIT((n) + 0)
38 #define XILINX_DPDMA_INTR_DESC_DONE_MASK		GENMASK(5, 0)
39 #define XILINX_DPDMA_INTR_NO_OSTAND(n)			BIT((n) + 6)
40 #define XILINX_DPDMA_INTR_NO_OSTAND_MASK		GENMASK(11, 6)
41 #define XILINX_DPDMA_INTR_AXI_ERR(n)			BIT((n) + 12)
42 #define XILINX_DPDMA_INTR_AXI_ERR_MASK			GENMASK(17, 12)
43 #define XILINX_DPDMA_INTR_DESC_ERR(n)			BIT((n) + 16)
44 #define XILINX_DPDMA_INTR_DESC_ERR_MASK			GENMASK(23, 18)
45 #define XILINX_DPDMA_INTR_WR_CMD_FIFO_FULL		BIT(24)
46 #define XILINX_DPDMA_INTR_WR_DATA_FIFO_FULL		BIT(25)
47 #define XILINX_DPDMA_INTR_AXI_4K_CROSS			BIT(26)
48 #define XILINX_DPDMA_INTR_VSYNC				BIT(27)
49 #define XILINX_DPDMA_INTR_CHAN_ERR_MASK			0x00041000
50 #define XILINX_DPDMA_INTR_CHAN_ERR			0x00fff000
51 #define XILINX_DPDMA_INTR_GLOBAL_ERR			0x07000000
52 #define XILINX_DPDMA_INTR_ERR_ALL			0x07fff000
53 #define XILINX_DPDMA_INTR_CHAN_MASK			0x00041041
54 #define XILINX_DPDMA_INTR_GLOBAL_MASK			0x0f000000
55 #define XILINX_DPDMA_INTR_ALL				0x0fffffff
56 #define XILINX_DPDMA_EISR				0x014
57 #define XILINX_DPDMA_EIMR				0x018
58 #define XILINX_DPDMA_EIEN				0x01c
59 #define XILINX_DPDMA_EIDS				0x020
60 #define XILINX_DPDMA_EINTR_INV_APB			BIT(0)
61 #define XILINX_DPDMA_EINTR_RD_AXI_ERR(n)		BIT((n) + 1)
62 #define XILINX_DPDMA_EINTR_RD_AXI_ERR_MASK		GENMASK(6, 1)
63 #define XILINX_DPDMA_EINTR_PRE_ERR(n)			BIT((n) + 7)
64 #define XILINX_DPDMA_EINTR_PRE_ERR_MASK			GENMASK(12, 7)
65 #define XILINX_DPDMA_EINTR_CRC_ERR(n)			BIT((n) + 13)
66 #define XILINX_DPDMA_EINTR_CRC_ERR_MASK			GENMASK(18, 13)
67 #define XILINX_DPDMA_EINTR_WR_AXI_ERR(n)		BIT((n) + 19)
68 #define XILINX_DPDMA_EINTR_WR_AXI_ERR_MASK		GENMASK(24, 19)
69 #define XILINX_DPDMA_EINTR_DESC_DONE_ERR(n)		BIT((n) + 25)
70 #define XILINX_DPDMA_EINTR_DESC_DONE_ERR_MASK		GENMASK(30, 25)
71 #define XILINX_DPDMA_EINTR_RD_CMD_FIFO_FULL		BIT(32)
72 #define XILINX_DPDMA_EINTR_CHAN_ERR_MASK		0x02082082
73 #define XILINX_DPDMA_EINTR_CHAN_ERR			0x7ffffffe
74 #define XILINX_DPDMA_EINTR_GLOBAL_ERR			0x80000001
75 #define XILINX_DPDMA_EINTR_ALL				0xffffffff
76 #define XILINX_DPDMA_CNTL				0x100
77 #define XILINX_DPDMA_GBL				0x104
78 #define XILINX_DPDMA_GBL_TRIG_MASK(n)			((n) << 0)
79 #define XILINX_DPDMA_GBL_RETRIG_MASK(n)			((n) << 6)
80 #define XILINX_DPDMA_ALC0_CNTL				0x108
81 #define XILINX_DPDMA_ALC0_STATUS			0x10c
82 #define XILINX_DPDMA_ALC0_MAX				0x110
83 #define XILINX_DPDMA_ALC0_MIN				0x114
84 #define XILINX_DPDMA_ALC0_ACC				0x118
85 #define XILINX_DPDMA_ALC0_ACC_TRAN			0x11c
86 #define XILINX_DPDMA_ALC1_CNTL				0x120
87 #define XILINX_DPDMA_ALC1_STATUS			0x124
88 #define XILINX_DPDMA_ALC1_MAX				0x128
89 #define XILINX_DPDMA_ALC1_MIN				0x12c
90 #define XILINX_DPDMA_ALC1_ACC				0x130
91 #define XILINX_DPDMA_ALC1_ACC_TRAN			0x134
92 
93 /* Channel register */
94 #define XILINX_DPDMA_CH_BASE				0x200
95 #define XILINX_DPDMA_CH_OFFSET				0x100
96 #define XILINX_DPDMA_CH_DESC_START_ADDRE		0x000
97 #define XILINX_DPDMA_CH_DESC_START_ADDRE_MASK		GENMASK(15, 0)
98 #define XILINX_DPDMA_CH_DESC_START_ADDR			0x004
99 #define XILINX_DPDMA_CH_DESC_NEXT_ADDRE			0x008
100 #define XILINX_DPDMA_CH_DESC_NEXT_ADDR			0x00c
101 #define XILINX_DPDMA_CH_PYLD_CUR_ADDRE			0x010
102 #define XILINX_DPDMA_CH_PYLD_CUR_ADDR			0x014
103 #define XILINX_DPDMA_CH_CNTL				0x018
104 #define XILINX_DPDMA_CH_CNTL_ENABLE			BIT(0)
105 #define XILINX_DPDMA_CH_CNTL_PAUSE			BIT(1)
106 #define XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK		GENMASK(5, 2)
107 #define XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK		GENMASK(9, 6)
108 #define XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK		GENMASK(13, 10)
109 #define XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS		11
110 #define XILINX_DPDMA_CH_STATUS				0x01c
111 #define XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK		GENMASK(24, 21)
112 #define XILINX_DPDMA_CH_VDO				0x020
113 #define XILINX_DPDMA_CH_PYLD_SZ				0x024
114 #define XILINX_DPDMA_CH_DESC_ID				0x028
115 
116 /* DPDMA descriptor fields */
117 #define XILINX_DPDMA_DESC_CONTROL_PREEMBLE		0xa5
118 #define XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR		BIT(8)
119 #define XILINX_DPDMA_DESC_CONTROL_DESC_UPDATE		BIT(9)
120 #define XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE		BIT(10)
121 #define XILINX_DPDMA_DESC_CONTROL_FRAG_MODE		BIT(18)
122 #define XILINX_DPDMA_DESC_CONTROL_LAST			BIT(19)
123 #define XILINX_DPDMA_DESC_CONTROL_ENABLE_CRC		BIT(20)
124 #define XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME		BIT(21)
125 #define XILINX_DPDMA_DESC_ID_MASK			GENMASK(15, 0)
126 #define XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK	GENMASK(17, 0)
127 #define XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK	GENMASK(31, 18)
128 #define XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK	GENMASK(15, 0)
129 #define XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK	GENMASK(31, 16)
130 
131 #define XILINX_DPDMA_ALIGN_BYTES			256
132 #define XILINX_DPDMA_LINESIZE_ALIGN_BITS		128
133 
134 #define XILINX_DPDMA_NUM_CHAN				6
135 
136 struct xilinx_dpdma_chan;
137 
138 /**
139  * struct xilinx_dpdma_hw_desc - DPDMA hardware descriptor
140  * @control: control configuration field
141  * @desc_id: descriptor ID
142  * @xfer_size: transfer size
143  * @hsize_stride: horizontal size and stride
144  * @timestamp_lsb: LSB of time stamp
145  * @timestamp_msb: MSB of time stamp
146  * @addr_ext: upper 16 bit of 48 bit address (next_desc and src_addr)
147  * @next_desc: next descriptor 32 bit address
148  * @src_addr: payload source address (1st page, 32 LSB)
149  * @addr_ext_23: payload source address (3nd and 3rd pages, 16 LSBs)
150  * @addr_ext_45: payload source address (4th and 5th pages, 16 LSBs)
151  * @src_addr2: payload source address (2nd page, 32 LSB)
152  * @src_addr3: payload source address (3rd page, 32 LSB)
153  * @src_addr4: payload source address (4th page, 32 LSB)
154  * @src_addr5: payload source address (5th page, 32 LSB)
155  * @crc: descriptor CRC
156  */
157 struct xilinx_dpdma_hw_desc {
158 	u32 control;
159 	u32 desc_id;
160 	u32 xfer_size;
161 	u32 hsize_stride;
162 	u32 timestamp_lsb;
163 	u32 timestamp_msb;
164 	u32 addr_ext;
165 	u32 next_desc;
166 	u32 src_addr;
167 	u32 addr_ext_23;
168 	u32 addr_ext_45;
169 	u32 src_addr2;
170 	u32 src_addr3;
171 	u32 src_addr4;
172 	u32 src_addr5;
173 	u32 crc;
174 } __aligned(XILINX_DPDMA_ALIGN_BYTES);
175 
176 /**
177  * struct xilinx_dpdma_sw_desc - DPDMA software descriptor
178  * @hw: DPDMA hardware descriptor
179  * @node: list node for software descriptors
180  * @dma_addr: DMA address of the software descriptor
181  */
182 struct xilinx_dpdma_sw_desc {
183 	struct xilinx_dpdma_hw_desc hw;
184 	struct list_head node;
185 	dma_addr_t dma_addr;
186 };
187 
188 /**
189  * struct xilinx_dpdma_tx_desc - DPDMA transaction descriptor
190  * @vdesc: virtual DMA descriptor
191  * @chan: DMA channel
192  * @descriptors: list of software descriptors
193  * @error: an error has been detected with this descriptor
194  */
195 struct xilinx_dpdma_tx_desc {
196 	struct virt_dma_desc vdesc;
197 	struct xilinx_dpdma_chan *chan;
198 	struct list_head descriptors;
199 	bool error;
200 };
201 
202 #define to_dpdma_tx_desc(_desc) \
203 	container_of(_desc, struct xilinx_dpdma_tx_desc, vdesc)
204 
205 /**
206  * struct xilinx_dpdma_chan - DPDMA channel
207  * @vchan: virtual DMA channel
208  * @reg: register base address
209  * @id: channel ID
210  * @wait_to_stop: queue to wait for outstanding transacitons before stopping
211  * @running: true if the channel is running
212  * @first_frame: flag for the first frame of stream
213  * @video_group: flag if multi-channel operation is needed for video channels
214  * @lock: lock to access struct xilinx_dpdma_chan
215  * @desc_pool: descriptor allocation pool
216  * @err_task: error IRQ bottom half handler
217  * @desc: References to descriptors being processed
218  * @desc.pending: Descriptor schedule to the hardware, pending execution
219  * @desc.active: Descriptor being executed by the hardware
220  * @xdev: DPDMA device
221  */
222 struct xilinx_dpdma_chan {
223 	struct virt_dma_chan vchan;
224 	void __iomem *reg;
225 	unsigned int id;
226 
227 	wait_queue_head_t wait_to_stop;
228 	bool running;
229 	bool first_frame;
230 	bool video_group;
231 
232 	spinlock_t lock; /* lock to access struct xilinx_dpdma_chan */
233 	struct dma_pool *desc_pool;
234 	struct tasklet_struct err_task;
235 
236 	struct {
237 		struct xilinx_dpdma_tx_desc *pending;
238 		struct xilinx_dpdma_tx_desc *active;
239 	} desc;
240 
241 	struct xilinx_dpdma_device *xdev;
242 };
243 
244 #define to_xilinx_chan(_chan) \
245 	container_of(_chan, struct xilinx_dpdma_chan, vchan.chan)
246 
247 /**
248  * struct xilinx_dpdma_device - DPDMA device
249  * @common: generic dma device structure
250  * @reg: register base address
251  * @dev: generic device structure
252  * @irq: the interrupt number
253  * @axi_clk: axi clock
254  * @chan: DPDMA channels
255  * @ext_addr: flag for 64 bit system (48 bit addressing)
256  */
257 struct xilinx_dpdma_device {
258 	struct dma_device common;
259 	void __iomem *reg;
260 	struct device *dev;
261 	int irq;
262 
263 	struct clk *axi_clk;
264 	struct xilinx_dpdma_chan *chan[XILINX_DPDMA_NUM_CHAN];
265 
266 	bool ext_addr;
267 };
268 
269 /* -----------------------------------------------------------------------------
270  * I/O Accessors
271  */
272 
273 static inline u32 dpdma_read(void __iomem *base, u32 offset)
274 {
275 	return ioread32(base + offset);
276 }
277 
278 static inline void dpdma_write(void __iomem *base, u32 offset, u32 val)
279 {
280 	iowrite32(val, base + offset);
281 }
282 
283 static inline void dpdma_clr(void __iomem *base, u32 offset, u32 clr)
284 {
285 	dpdma_write(base, offset, dpdma_read(base, offset) & ~clr);
286 }
287 
288 static inline void dpdma_set(void __iomem *base, u32 offset, u32 set)
289 {
290 	dpdma_write(base, offset, dpdma_read(base, offset) | set);
291 }
292 
293 /* -----------------------------------------------------------------------------
294  * Descriptor Operations
295  */
296 
297 /**
298  * xilinx_dpdma_sw_desc_set_dma_addrs - Set DMA addresses in the descriptor
299  * @xdev: DPDMA device
300  * @sw_desc: The software descriptor in which to set DMA addresses
301  * @prev: The previous descriptor
302  * @dma_addr: array of dma addresses
303  * @num_src_addr: number of addresses in @dma_addr
304  *
305  * Set all the DMA addresses in the hardware descriptor corresponding to @dev
306  * from @dma_addr. If a previous descriptor is specified in @prev, its next
307  * descriptor DMA address is set to the DMA address of @sw_desc. @prev may be
308  * identical to @sw_desc for cyclic transfers.
309  */
310 static void xilinx_dpdma_sw_desc_set_dma_addrs(struct xilinx_dpdma_device *xdev,
311 					       struct xilinx_dpdma_sw_desc *sw_desc,
312 					       struct xilinx_dpdma_sw_desc *prev,
313 					       dma_addr_t dma_addr[],
314 					       unsigned int num_src_addr)
315 {
316 	struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
317 	unsigned int i;
318 
319 	hw_desc->src_addr = lower_32_bits(dma_addr[0]);
320 	if (xdev->ext_addr)
321 		hw_desc->addr_ext |=
322 			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK,
323 				   upper_32_bits(dma_addr[0]));
324 
325 	for (i = 1; i < num_src_addr; i++) {
326 		u32 *addr = &hw_desc->src_addr2;
327 
328 		addr[i-1] = lower_32_bits(dma_addr[i]);
329 
330 		if (xdev->ext_addr) {
331 			u32 *addr_ext = &hw_desc->addr_ext_23;
332 			u32 addr_msb;
333 
334 			addr_msb = upper_32_bits(dma_addr[i]) & GENMASK(15, 0);
335 			addr_msb <<= 16 * ((i - 1) % 2);
336 			addr_ext[(i - 1) / 2] |= addr_msb;
337 		}
338 	}
339 
340 	if (!prev)
341 		return;
342 
343 	prev->hw.next_desc = lower_32_bits(sw_desc->dma_addr);
344 	if (xdev->ext_addr)
345 		prev->hw.addr_ext |=
346 			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK,
347 				   upper_32_bits(sw_desc->dma_addr));
348 }
349 
350 /**
351  * xilinx_dpdma_chan_alloc_sw_desc - Allocate a software descriptor
352  * @chan: DPDMA channel
353  *
354  * Allocate a software descriptor from the channel's descriptor pool.
355  *
356  * Return: a software descriptor or NULL.
357  */
358 static struct xilinx_dpdma_sw_desc *
359 xilinx_dpdma_chan_alloc_sw_desc(struct xilinx_dpdma_chan *chan)
360 {
361 	struct xilinx_dpdma_sw_desc *sw_desc;
362 	dma_addr_t dma_addr;
363 
364 	sw_desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &dma_addr);
365 	if (!sw_desc)
366 		return NULL;
367 
368 	sw_desc->dma_addr = dma_addr;
369 
370 	return sw_desc;
371 }
372 
373 /**
374  * xilinx_dpdma_chan_free_sw_desc - Free a software descriptor
375  * @chan: DPDMA channel
376  * @sw_desc: software descriptor to free
377  *
378  * Free a software descriptor from the channel's descriptor pool.
379  */
380 static void
381 xilinx_dpdma_chan_free_sw_desc(struct xilinx_dpdma_chan *chan,
382 			       struct xilinx_dpdma_sw_desc *sw_desc)
383 {
384 	dma_pool_free(chan->desc_pool, sw_desc, sw_desc->dma_addr);
385 }
386 
387 /**
388  * xilinx_dpdma_chan_dump_tx_desc - Dump a tx descriptor
389  * @chan: DPDMA channel
390  * @tx_desc: tx descriptor to dump
391  *
392  * Dump contents of a tx descriptor
393  */
394 static void xilinx_dpdma_chan_dump_tx_desc(struct xilinx_dpdma_chan *chan,
395 					   struct xilinx_dpdma_tx_desc *tx_desc)
396 {
397 	struct xilinx_dpdma_sw_desc *sw_desc;
398 	struct device *dev = chan->xdev->dev;
399 	unsigned int i = 0;
400 
401 	dev_dbg(dev, "------- TX descriptor dump start -------\n");
402 	dev_dbg(dev, "------- channel ID = %d -------\n", chan->id);
403 
404 	list_for_each_entry(sw_desc, &tx_desc->descriptors, node) {
405 		struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
406 
407 		dev_dbg(dev, "------- HW descriptor %d -------\n", i++);
408 		dev_dbg(dev, "descriptor DMA addr: %pad\n", &sw_desc->dma_addr);
409 		dev_dbg(dev, "control: 0x%08x\n", hw_desc->control);
410 		dev_dbg(dev, "desc_id: 0x%08x\n", hw_desc->desc_id);
411 		dev_dbg(dev, "xfer_size: 0x%08x\n", hw_desc->xfer_size);
412 		dev_dbg(dev, "hsize_stride: 0x%08x\n", hw_desc->hsize_stride);
413 		dev_dbg(dev, "timestamp_lsb: 0x%08x\n", hw_desc->timestamp_lsb);
414 		dev_dbg(dev, "timestamp_msb: 0x%08x\n", hw_desc->timestamp_msb);
415 		dev_dbg(dev, "addr_ext: 0x%08x\n", hw_desc->addr_ext);
416 		dev_dbg(dev, "next_desc: 0x%08x\n", hw_desc->next_desc);
417 		dev_dbg(dev, "src_addr: 0x%08x\n", hw_desc->src_addr);
418 		dev_dbg(dev, "addr_ext_23: 0x%08x\n", hw_desc->addr_ext_23);
419 		dev_dbg(dev, "addr_ext_45: 0x%08x\n", hw_desc->addr_ext_45);
420 		dev_dbg(dev, "src_addr2: 0x%08x\n", hw_desc->src_addr2);
421 		dev_dbg(dev, "src_addr3: 0x%08x\n", hw_desc->src_addr3);
422 		dev_dbg(dev, "src_addr4: 0x%08x\n", hw_desc->src_addr4);
423 		dev_dbg(dev, "src_addr5: 0x%08x\n", hw_desc->src_addr5);
424 		dev_dbg(dev, "crc: 0x%08x\n", hw_desc->crc);
425 	}
426 
427 	dev_dbg(dev, "------- TX descriptor dump end -------\n");
428 }
429 
430 /**
431  * xilinx_dpdma_chan_alloc_tx_desc - Allocate a transaction descriptor
432  * @chan: DPDMA channel
433  *
434  * Allocate a tx descriptor.
435  *
436  * Return: a tx descriptor or NULL.
437  */
438 static struct xilinx_dpdma_tx_desc *
439 xilinx_dpdma_chan_alloc_tx_desc(struct xilinx_dpdma_chan *chan)
440 {
441 	struct xilinx_dpdma_tx_desc *tx_desc;
442 
443 	tx_desc = kzalloc(sizeof(*tx_desc), GFP_NOWAIT);
444 	if (!tx_desc)
445 		return NULL;
446 
447 	INIT_LIST_HEAD(&tx_desc->descriptors);
448 	tx_desc->chan = chan;
449 	tx_desc->error = false;
450 
451 	return tx_desc;
452 }
453 
454 /**
455  * xilinx_dpdma_chan_free_tx_desc - Free a virtual DMA descriptor
456  * @vdesc: virtual DMA descriptor
457  *
458  * Free the virtual DMA descriptor @vdesc including its software descriptors.
459  */
460 static void xilinx_dpdma_chan_free_tx_desc(struct virt_dma_desc *vdesc)
461 {
462 	struct xilinx_dpdma_sw_desc *sw_desc, *next;
463 	struct xilinx_dpdma_tx_desc *desc;
464 
465 	if (!vdesc)
466 		return;
467 
468 	desc = to_dpdma_tx_desc(vdesc);
469 
470 	list_for_each_entry_safe(sw_desc, next, &desc->descriptors, node) {
471 		list_del(&sw_desc->node);
472 		xilinx_dpdma_chan_free_sw_desc(desc->chan, sw_desc);
473 	}
474 
475 	kfree(desc);
476 }
477 
478 /**
479  * xilinx_dpdma_chan_prep_interleaved_dma - Prepare an interleaved dma
480  *					    descriptor
481  * @chan: DPDMA channel
482  * @xt: dma interleaved template
483  *
484  * Prepare a tx descriptor including internal software/hardware descriptors
485  * based on @xt.
486  *
487  * Return: A DPDMA TX descriptor on success, or NULL.
488  */
489 static struct xilinx_dpdma_tx_desc *
490 xilinx_dpdma_chan_prep_interleaved_dma(struct xilinx_dpdma_chan *chan,
491 				       struct dma_interleaved_template *xt)
492 {
493 	struct xilinx_dpdma_tx_desc *tx_desc;
494 	struct xilinx_dpdma_sw_desc *sw_desc;
495 	struct xilinx_dpdma_hw_desc *hw_desc;
496 	size_t hsize = xt->sgl[0].size;
497 	size_t stride = hsize + xt->sgl[0].icg;
498 
499 	if (!IS_ALIGNED(xt->src_start, XILINX_DPDMA_ALIGN_BYTES)) {
500 		dev_err(chan->xdev->dev, "buffer should be aligned at %d B\n",
501 			XILINX_DPDMA_ALIGN_BYTES);
502 		return NULL;
503 	}
504 
505 	tx_desc = xilinx_dpdma_chan_alloc_tx_desc(chan);
506 	if (!tx_desc)
507 		return NULL;
508 
509 	sw_desc = xilinx_dpdma_chan_alloc_sw_desc(chan);
510 	if (!sw_desc) {
511 		xilinx_dpdma_chan_free_tx_desc(&tx_desc->vdesc);
512 		return NULL;
513 	}
514 
515 	xilinx_dpdma_sw_desc_set_dma_addrs(chan->xdev, sw_desc, sw_desc,
516 					   &xt->src_start, 1);
517 
518 	hw_desc = &sw_desc->hw;
519 	hsize = ALIGN(hsize, XILINX_DPDMA_LINESIZE_ALIGN_BITS / 8);
520 	hw_desc->xfer_size = hsize * xt->numf;
521 	hw_desc->hsize_stride =
522 		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK, hsize) |
523 		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK,
524 			   stride / 16);
525 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_PREEMBLE;
526 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR;
527 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE;
528 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME;
529 
530 	list_add_tail(&sw_desc->node, &tx_desc->descriptors);
531 
532 	return tx_desc;
533 }
534 
535 /* -----------------------------------------------------------------------------
536  * DPDMA Channel Operations
537  */
538 
539 /**
540  * xilinx_dpdma_chan_enable - Enable the channel
541  * @chan: DPDMA channel
542  *
543  * Enable the channel and its interrupts. Set the QoS values for video class.
544  */
545 static void xilinx_dpdma_chan_enable(struct xilinx_dpdma_chan *chan)
546 {
547 	u32 reg;
548 
549 	reg = (XILINX_DPDMA_INTR_CHAN_MASK << chan->id)
550 	    | XILINX_DPDMA_INTR_GLOBAL_MASK;
551 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
552 	reg = (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id)
553 	    | XILINX_DPDMA_INTR_GLOBAL_ERR;
554 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
555 
556 	reg = XILINX_DPDMA_CH_CNTL_ENABLE
557 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK,
558 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
559 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK,
560 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
561 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK,
562 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS);
563 	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, reg);
564 }
565 
566 /**
567  * xilinx_dpdma_chan_disable - Disable the channel
568  * @chan: DPDMA channel
569  *
570  * Disable the channel and its interrupts.
571  */
572 static void xilinx_dpdma_chan_disable(struct xilinx_dpdma_chan *chan)
573 {
574 	u32 reg;
575 
576 	reg = XILINX_DPDMA_INTR_CHAN_MASK << chan->id;
577 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
578 	reg = XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id;
579 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
580 
581 	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_ENABLE);
582 }
583 
584 /**
585  * xilinx_dpdma_chan_pause - Pause the channel
586  * @chan: DPDMA channel
587  *
588  * Pause the channel.
589  */
590 static void xilinx_dpdma_chan_pause(struct xilinx_dpdma_chan *chan)
591 {
592 	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
593 }
594 
595 /**
596  * xilinx_dpdma_chan_unpause - Unpause the channel
597  * @chan: DPDMA channel
598  *
599  * Unpause the channel.
600  */
601 static void xilinx_dpdma_chan_unpause(struct xilinx_dpdma_chan *chan)
602 {
603 	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
604 }
605 
606 static u32 xilinx_dpdma_chan_video_group_ready(struct xilinx_dpdma_chan *chan)
607 {
608 	struct xilinx_dpdma_device *xdev = chan->xdev;
609 	u32 channels = 0;
610 	unsigned int i;
611 
612 	for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
613 		if (xdev->chan[i]->video_group && !xdev->chan[i]->running)
614 			return 0;
615 
616 		if (xdev->chan[i]->video_group)
617 			channels |= BIT(i);
618 	}
619 
620 	return channels;
621 }
622 
623 /**
624  * xilinx_dpdma_chan_queue_transfer - Queue the next transfer
625  * @chan: DPDMA channel
626  *
627  * Queue the next descriptor, if any, to the hardware. If the channel is
628  * stopped, start it first. Otherwise retrigger it with the next descriptor.
629  */
630 static void xilinx_dpdma_chan_queue_transfer(struct xilinx_dpdma_chan *chan)
631 {
632 	struct xilinx_dpdma_device *xdev = chan->xdev;
633 	struct xilinx_dpdma_sw_desc *sw_desc;
634 	struct xilinx_dpdma_tx_desc *desc;
635 	struct virt_dma_desc *vdesc;
636 	u32 reg, channels;
637 
638 	lockdep_assert_held(&chan->lock);
639 
640 	if (chan->desc.pending)
641 		return;
642 
643 	if (!chan->running) {
644 		xilinx_dpdma_chan_unpause(chan);
645 		xilinx_dpdma_chan_enable(chan);
646 		chan->first_frame = true;
647 		chan->running = true;
648 	}
649 
650 	if (chan->video_group)
651 		channels = xilinx_dpdma_chan_video_group_ready(chan);
652 	else
653 		channels = BIT(chan->id);
654 
655 	if (!channels)
656 		return;
657 
658 	vdesc = vchan_next_desc(&chan->vchan);
659 	if (!vdesc)
660 		return;
661 
662 	desc = to_dpdma_tx_desc(vdesc);
663 	chan->desc.pending = desc;
664 	list_del(&desc->vdesc.node);
665 
666 	/*
667 	 * Assign the cookie to descriptors in this transaction. Only 16 bit
668 	 * will be used, but it should be enough.
669 	 */
670 	list_for_each_entry(sw_desc, &desc->descriptors, node)
671 		sw_desc->hw.desc_id = desc->vdesc.tx.cookie;
672 
673 	sw_desc = list_first_entry(&desc->descriptors,
674 				   struct xilinx_dpdma_sw_desc, node);
675 	dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR,
676 		    lower_32_bits(sw_desc->dma_addr));
677 	if (xdev->ext_addr)
678 		dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE,
679 			    FIELD_PREP(XILINX_DPDMA_CH_DESC_START_ADDRE_MASK,
680 				       upper_32_bits(sw_desc->dma_addr)));
681 
682 	if (chan->first_frame)
683 		reg = XILINX_DPDMA_GBL_TRIG_MASK(channels);
684 	else
685 		reg = XILINX_DPDMA_GBL_RETRIG_MASK(channels);
686 
687 	chan->first_frame = false;
688 
689 	dpdma_write(xdev->reg, XILINX_DPDMA_GBL, reg);
690 }
691 
692 /**
693  * xilinx_dpdma_chan_ostand - Number of outstanding transactions
694  * @chan: DPDMA channel
695  *
696  * Read and return the number of outstanding transactions from register.
697  *
698  * Return: Number of outstanding transactions from the status register.
699  */
700 static u32 xilinx_dpdma_chan_ostand(struct xilinx_dpdma_chan *chan)
701 {
702 	return FIELD_GET(XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK,
703 			 dpdma_read(chan->reg, XILINX_DPDMA_CH_STATUS));
704 }
705 
706 /**
707  * xilinx_dpdma_chan_no_ostand - Notify no outstanding transaction event
708  * @chan: DPDMA channel
709  *
710  * Notify waiters for no outstanding event, so waiters can stop the channel
711  * safely. This function is supposed to be called when 'no outstanding'
712  * interrupt is generated. The 'no outstanding' interrupt is disabled and
713  * should be re-enabled when this event is handled. If the channel status
714  * register still shows some number of outstanding transactions, the interrupt
715  * remains enabled.
716  *
717  * Return: 0 on success. On failure, -EWOULDBLOCK if there's still outstanding
718  * transaction(s).
719  */
720 static int xilinx_dpdma_chan_notify_no_ostand(struct xilinx_dpdma_chan *chan)
721 {
722 	u32 cnt;
723 
724 	cnt = xilinx_dpdma_chan_ostand(chan);
725 	if (cnt) {
726 		dev_dbg(chan->xdev->dev, "%d outstanding transactions\n", cnt);
727 		return -EWOULDBLOCK;
728 	}
729 
730 	/* Disable 'no outstanding' interrupt */
731 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IDS,
732 		    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
733 	wake_up(&chan->wait_to_stop);
734 
735 	return 0;
736 }
737 
738 /**
739  * xilinx_dpdma_chan_wait_no_ostand - Wait for the no outstanding irq
740  * @chan: DPDMA channel
741  *
742  * Wait for the no outstanding transaction interrupt. This functions can sleep
743  * for 50ms.
744  *
745  * Return: 0 on success. On failure, -ETIMEOUT for time out, or the error code
746  * from wait_event_interruptible_timeout().
747  */
748 static int xilinx_dpdma_chan_wait_no_ostand(struct xilinx_dpdma_chan *chan)
749 {
750 	int ret;
751 
752 	/* Wait for a no outstanding transaction interrupt upto 50msec */
753 	ret = wait_event_interruptible_timeout(chan->wait_to_stop,
754 					       !xilinx_dpdma_chan_ostand(chan),
755 					       msecs_to_jiffies(50));
756 	if (ret > 0) {
757 		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
758 			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
759 		return 0;
760 	}
761 
762 	dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
763 		xilinx_dpdma_chan_ostand(chan));
764 
765 	if (ret == 0)
766 		return -ETIMEDOUT;
767 
768 	return ret;
769 }
770 
771 /**
772  * xilinx_dpdma_chan_poll_no_ostand - Poll the outstanding transaction status
773  * @chan: DPDMA channel
774  *
775  * Poll the outstanding transaction status, and return when there's no
776  * outstanding transaction. This functions can be used in the interrupt context
777  * or where the atomicity is required. Calling thread may wait more than 50ms.
778  *
779  * Return: 0 on success, or -ETIMEDOUT.
780  */
781 static int xilinx_dpdma_chan_poll_no_ostand(struct xilinx_dpdma_chan *chan)
782 {
783 	u32 cnt, loop = 50000;
784 
785 	/* Poll at least for 50ms (20 fps). */
786 	do {
787 		cnt = xilinx_dpdma_chan_ostand(chan);
788 		udelay(1);
789 	} while (loop-- > 0 && cnt);
790 
791 	if (loop) {
792 		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
793 			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
794 		return 0;
795 	}
796 
797 	dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
798 		xilinx_dpdma_chan_ostand(chan));
799 
800 	return -ETIMEDOUT;
801 }
802 
803 /**
804  * xilinx_dpdma_chan_stop - Stop the channel
805  * @chan: DPDMA channel
806  *
807  * Stop a previously paused channel by first waiting for completion of all
808  * outstanding transaction and then disabling the channel.
809  *
810  * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
811  */
812 static int xilinx_dpdma_chan_stop(struct xilinx_dpdma_chan *chan)
813 {
814 	unsigned long flags;
815 	int ret;
816 
817 	ret = xilinx_dpdma_chan_wait_no_ostand(chan);
818 	if (ret)
819 		return ret;
820 
821 	spin_lock_irqsave(&chan->lock, flags);
822 	xilinx_dpdma_chan_disable(chan);
823 	chan->running = false;
824 	spin_unlock_irqrestore(&chan->lock, flags);
825 
826 	return 0;
827 }
828 
829 /**
830  * xilinx_dpdma_chan_done_irq - Handle hardware descriptor completion
831  * @chan: DPDMA channel
832  *
833  * Handle completion of the currently active descriptor (@chan->desc.active). As
834  * we currently support cyclic transfers only, this just invokes the cyclic
835  * callback. The descriptor will be completed at the VSYNC interrupt when a new
836  * descriptor replaces it.
837  */
838 static void xilinx_dpdma_chan_done_irq(struct xilinx_dpdma_chan *chan)
839 {
840 	struct xilinx_dpdma_tx_desc *active = chan->desc.active;
841 	unsigned long flags;
842 
843 	spin_lock_irqsave(&chan->lock, flags);
844 
845 	if (active)
846 		vchan_cyclic_callback(&active->vdesc);
847 	else
848 		dev_warn(chan->xdev->dev,
849 			 "DONE IRQ with no active descriptor!\n");
850 
851 	spin_unlock_irqrestore(&chan->lock, flags);
852 }
853 
854 /**
855  * xilinx_dpdma_chan_vsync_irq - Handle hardware descriptor scheduling
856  * @chan: DPDMA channel
857  *
858  * At VSYNC the active descriptor may have been replaced by the pending
859  * descriptor. Detect this through the DESC_ID and perform appropriate
860  * bookkeeping.
861  */
862 static void xilinx_dpdma_chan_vsync_irq(struct  xilinx_dpdma_chan *chan)
863 {
864 	struct xilinx_dpdma_tx_desc *pending;
865 	struct xilinx_dpdma_sw_desc *sw_desc;
866 	unsigned long flags;
867 	u32 desc_id;
868 
869 	spin_lock_irqsave(&chan->lock, flags);
870 
871 	pending = chan->desc.pending;
872 	if (!chan->running || !pending)
873 		goto out;
874 
875 	desc_id = dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_ID);
876 
877 	/* If the retrigger raced with vsync, retry at the next frame. */
878 	sw_desc = list_first_entry(&pending->descriptors,
879 				   struct xilinx_dpdma_sw_desc, node);
880 	if (sw_desc->hw.desc_id != desc_id)
881 		goto out;
882 
883 	/*
884 	 * Complete the active descriptor, if any, promote the pending
885 	 * descriptor to active, and queue the next transfer, if any.
886 	 */
887 	if (chan->desc.active)
888 		vchan_cookie_complete(&chan->desc.active->vdesc);
889 	chan->desc.active = pending;
890 	chan->desc.pending = NULL;
891 
892 	xilinx_dpdma_chan_queue_transfer(chan);
893 
894 out:
895 	spin_unlock_irqrestore(&chan->lock, flags);
896 }
897 
898 /**
899  * xilinx_dpdma_chan_err - Detect any channel error
900  * @chan: DPDMA channel
901  * @isr: masked Interrupt Status Register
902  * @eisr: Error Interrupt Status Register
903  *
904  * Return: true if any channel error occurs, or false otherwise.
905  */
906 static bool
907 xilinx_dpdma_chan_err(struct xilinx_dpdma_chan *chan, u32 isr, u32 eisr)
908 {
909 	if (!chan)
910 		return false;
911 
912 	if (chan->running &&
913 	    ((isr & (XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id)) ||
914 	    (eisr & (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id))))
915 		return true;
916 
917 	return false;
918 }
919 
920 /**
921  * xilinx_dpdma_chan_handle_err - DPDMA channel error handling
922  * @chan: DPDMA channel
923  *
924  * This function is called when any channel error or any global error occurs.
925  * The function disables the paused channel by errors and determines
926  * if the current active descriptor can be rescheduled depending on
927  * the descriptor status.
928  */
929 static void xilinx_dpdma_chan_handle_err(struct xilinx_dpdma_chan *chan)
930 {
931 	struct xilinx_dpdma_device *xdev = chan->xdev;
932 	struct xilinx_dpdma_tx_desc *active;
933 	unsigned long flags;
934 
935 	spin_lock_irqsave(&chan->lock, flags);
936 
937 	dev_dbg(xdev->dev, "cur desc addr = 0x%04x%08x\n",
938 		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE),
939 		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR));
940 	dev_dbg(xdev->dev, "cur payload addr = 0x%04x%08x\n",
941 		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDRE),
942 		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDR));
943 
944 	xilinx_dpdma_chan_disable(chan);
945 	chan->running = false;
946 
947 	if (!chan->desc.active)
948 		goto out_unlock;
949 
950 	active = chan->desc.active;
951 	chan->desc.active = NULL;
952 
953 	xilinx_dpdma_chan_dump_tx_desc(chan, active);
954 
955 	if (active->error)
956 		dev_dbg(xdev->dev, "repeated error on desc\n");
957 
958 	/* Reschedule if there's no new descriptor */
959 	if (!chan->desc.pending &&
960 	    list_empty(&chan->vchan.desc_issued)) {
961 		active->error = true;
962 		list_add_tail(&active->vdesc.node,
963 			      &chan->vchan.desc_issued);
964 	} else {
965 		xilinx_dpdma_chan_free_tx_desc(&active->vdesc);
966 	}
967 
968 out_unlock:
969 	spin_unlock_irqrestore(&chan->lock, flags);
970 }
971 
972 /* -----------------------------------------------------------------------------
973  * DMA Engine Operations
974  */
975 
976 static struct dma_async_tx_descriptor *
977 xilinx_dpdma_prep_interleaved_dma(struct dma_chan *dchan,
978 				  struct dma_interleaved_template *xt,
979 				  unsigned long flags)
980 {
981 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
982 	struct xilinx_dpdma_tx_desc *desc;
983 
984 	if (xt->dir != DMA_MEM_TO_DEV)
985 		return NULL;
986 
987 	if (!xt->numf || !xt->sgl[0].size)
988 		return NULL;
989 
990 	if (!(flags & DMA_PREP_REPEAT) || !(flags & DMA_PREP_LOAD_EOT))
991 		return NULL;
992 
993 	desc = xilinx_dpdma_chan_prep_interleaved_dma(chan, xt);
994 	if (!desc)
995 		return NULL;
996 
997 	vchan_tx_prep(&chan->vchan, &desc->vdesc, flags | DMA_CTRL_ACK);
998 
999 	return &desc->vdesc.tx;
1000 }
1001 
1002 /**
1003  * xilinx_dpdma_alloc_chan_resources - Allocate resources for the channel
1004  * @dchan: DMA channel
1005  *
1006  * Allocate a descriptor pool for the channel.
1007  *
1008  * Return: 0 on success, or -ENOMEM if failed to allocate a pool.
1009  */
1010 static int xilinx_dpdma_alloc_chan_resources(struct dma_chan *dchan)
1011 {
1012 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1013 	size_t align = __alignof__(struct xilinx_dpdma_sw_desc);
1014 
1015 	chan->desc_pool = dma_pool_create(dev_name(chan->xdev->dev),
1016 					  chan->xdev->dev,
1017 					  sizeof(struct xilinx_dpdma_sw_desc),
1018 					  align, 0);
1019 	if (!chan->desc_pool) {
1020 		dev_err(chan->xdev->dev,
1021 			"failed to allocate a descriptor pool\n");
1022 		return -ENOMEM;
1023 	}
1024 
1025 	return 0;
1026 }
1027 
1028 /**
1029  * xilinx_dpdma_free_chan_resources - Free all resources for the channel
1030  * @dchan: DMA channel
1031  *
1032  * Free resources associated with the virtual DMA channel, and destroy the
1033  * descriptor pool.
1034  */
1035 static void xilinx_dpdma_free_chan_resources(struct dma_chan *dchan)
1036 {
1037 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1038 
1039 	vchan_free_chan_resources(&chan->vchan);
1040 
1041 	dma_pool_destroy(chan->desc_pool);
1042 	chan->desc_pool = NULL;
1043 }
1044 
1045 static void xilinx_dpdma_issue_pending(struct dma_chan *dchan)
1046 {
1047 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1048 	unsigned long flags;
1049 
1050 	spin_lock_irqsave(&chan->vchan.lock, flags);
1051 	if (vchan_issue_pending(&chan->vchan))
1052 		xilinx_dpdma_chan_queue_transfer(chan);
1053 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1054 }
1055 
1056 static int xilinx_dpdma_config(struct dma_chan *dchan,
1057 			       struct dma_slave_config *config)
1058 {
1059 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1060 	unsigned long flags;
1061 
1062 	/*
1063 	 * The destination address doesn't need to be specified as the DPDMA is
1064 	 * hardwired to the destination (the DP controller). The transfer
1065 	 * width, burst size and port window size are thus meaningless, they're
1066 	 * fixed both on the DPDMA side and on the DP controller side.
1067 	 */
1068 
1069 	spin_lock_irqsave(&chan->lock, flags);
1070 
1071 	/*
1072 	 * Abuse the slave_id to indicate that the channel is part of a video
1073 	 * group.
1074 	 */
1075 	if (chan->id <= ZYNQMP_DPDMA_VIDEO2)
1076 		chan->video_group = config->slave_id != 0;
1077 
1078 	spin_unlock_irqrestore(&chan->lock, flags);
1079 
1080 	return 0;
1081 }
1082 
1083 static int xilinx_dpdma_pause(struct dma_chan *dchan)
1084 {
1085 	xilinx_dpdma_chan_pause(to_xilinx_chan(dchan));
1086 
1087 	return 0;
1088 }
1089 
1090 static int xilinx_dpdma_resume(struct dma_chan *dchan)
1091 {
1092 	xilinx_dpdma_chan_unpause(to_xilinx_chan(dchan));
1093 
1094 	return 0;
1095 }
1096 
1097 /**
1098  * xilinx_dpdma_terminate_all - Terminate the channel and descriptors
1099  * @dchan: DMA channel
1100  *
1101  * Pause the channel without waiting for ongoing transfers to complete. Waiting
1102  * for completion is performed by xilinx_dpdma_synchronize() that will disable
1103  * the channel to complete the stop.
1104  *
1105  * All the descriptors associated with the channel that are guaranteed not to
1106  * be touched by the hardware. The pending and active descriptor are not
1107  * touched, and will be freed either upon completion, or by
1108  * xilinx_dpdma_synchronize().
1109  *
1110  * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
1111  */
1112 static int xilinx_dpdma_terminate_all(struct dma_chan *dchan)
1113 {
1114 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1115 	struct xilinx_dpdma_device *xdev = chan->xdev;
1116 	LIST_HEAD(descriptors);
1117 	unsigned long flags;
1118 	unsigned int i;
1119 
1120 	/* Pause the channel (including the whole video group if applicable). */
1121 	if (chan->video_group) {
1122 		for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
1123 			if (xdev->chan[i]->video_group &&
1124 			    xdev->chan[i]->running) {
1125 				xilinx_dpdma_chan_pause(xdev->chan[i]);
1126 				xdev->chan[i]->video_group = false;
1127 			}
1128 		}
1129 	} else {
1130 		xilinx_dpdma_chan_pause(chan);
1131 	}
1132 
1133 	/* Gather all the descriptors we can free and free them. */
1134 	spin_lock_irqsave(&chan->vchan.lock, flags);
1135 	vchan_get_all_descriptors(&chan->vchan, &descriptors);
1136 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1137 
1138 	vchan_dma_desc_free_list(&chan->vchan, &descriptors);
1139 
1140 	return 0;
1141 }
1142 
1143 /**
1144  * xilinx_dpdma_synchronize - Synchronize callback execution
1145  * @dchan: DMA channel
1146  *
1147  * Synchronizing callback execution ensures that all previously issued
1148  * transfers have completed and all associated callbacks have been called and
1149  * have returned.
1150  *
1151  * This function waits for the DMA channel to stop. It assumes it has been
1152  * paused by a previous call to dmaengine_terminate_async(), and that no new
1153  * pending descriptors have been issued with dma_async_issue_pending(). The
1154  * behaviour is undefined otherwise.
1155  */
1156 static void xilinx_dpdma_synchronize(struct dma_chan *dchan)
1157 {
1158 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1159 	unsigned long flags;
1160 
1161 	xilinx_dpdma_chan_stop(chan);
1162 
1163 	spin_lock_irqsave(&chan->vchan.lock, flags);
1164 	if (chan->desc.pending) {
1165 		vchan_terminate_vdesc(&chan->desc.pending->vdesc);
1166 		chan->desc.pending = NULL;
1167 	}
1168 	if (chan->desc.active) {
1169 		vchan_terminate_vdesc(&chan->desc.active->vdesc);
1170 		chan->desc.active = NULL;
1171 	}
1172 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1173 
1174 	vchan_synchronize(&chan->vchan);
1175 }
1176 
1177 /* -----------------------------------------------------------------------------
1178  * Interrupt and Tasklet Handling
1179  */
1180 
1181 /**
1182  * xilinx_dpdma_err - Detect any global error
1183  * @isr: Interrupt Status Register
1184  * @eisr: Error Interrupt Status Register
1185  *
1186  * Return: True if any global error occurs, or false otherwise.
1187  */
1188 static bool xilinx_dpdma_err(u32 isr, u32 eisr)
1189 {
1190 	if (isr & XILINX_DPDMA_INTR_GLOBAL_ERR ||
1191 	    eisr & XILINX_DPDMA_EINTR_GLOBAL_ERR)
1192 		return true;
1193 
1194 	return false;
1195 }
1196 
1197 /**
1198  * xilinx_dpdma_handle_err_irq - Handle DPDMA error interrupt
1199  * @xdev: DPDMA device
1200  * @isr: masked Interrupt Status Register
1201  * @eisr: Error Interrupt Status Register
1202  *
1203  * Handle if any error occurs based on @isr and @eisr. This function disables
1204  * corresponding error interrupts, and those should be re-enabled once handling
1205  * is done.
1206  */
1207 static void xilinx_dpdma_handle_err_irq(struct xilinx_dpdma_device *xdev,
1208 					u32 isr, u32 eisr)
1209 {
1210 	bool err = xilinx_dpdma_err(isr, eisr);
1211 	unsigned int i;
1212 
1213 	dev_dbg_ratelimited(xdev->dev,
1214 			    "error irq: isr = 0x%08x, eisr = 0x%08x\n",
1215 			    isr, eisr);
1216 
1217 	/* Disable channel error interrupts until errors are handled. */
1218 	dpdma_write(xdev->reg, XILINX_DPDMA_IDS,
1219 		    isr & ~XILINX_DPDMA_INTR_GLOBAL_ERR);
1220 	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS,
1221 		    eisr & ~XILINX_DPDMA_EINTR_GLOBAL_ERR);
1222 
1223 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1224 		if (err || xilinx_dpdma_chan_err(xdev->chan[i], isr, eisr))
1225 			tasklet_schedule(&xdev->chan[i]->err_task);
1226 }
1227 
1228 /**
1229  * xilinx_dpdma_enable_irq - Enable interrupts
1230  * @xdev: DPDMA device
1231  *
1232  * Enable interrupts.
1233  */
1234 static void xilinx_dpdma_enable_irq(struct xilinx_dpdma_device *xdev)
1235 {
1236 	dpdma_write(xdev->reg, XILINX_DPDMA_IEN, XILINX_DPDMA_INTR_ALL);
1237 	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN, XILINX_DPDMA_EINTR_ALL);
1238 }
1239 
1240 /**
1241  * xilinx_dpdma_disable_irq - Disable interrupts
1242  * @xdev: DPDMA device
1243  *
1244  * Disable interrupts.
1245  */
1246 static void xilinx_dpdma_disable_irq(struct xilinx_dpdma_device *xdev)
1247 {
1248 	dpdma_write(xdev->reg, XILINX_DPDMA_IDS, XILINX_DPDMA_INTR_ERR_ALL);
1249 	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS, XILINX_DPDMA_EINTR_ALL);
1250 }
1251 
1252 /**
1253  * xilinx_dpdma_chan_err_task - Per channel tasklet for error handling
1254  * @data: tasklet data to be casted to DPDMA channel structure
1255  *
1256  * Per channel error handling tasklet. This function waits for the outstanding
1257  * transaction to complete and triggers error handling. After error handling,
1258  * re-enable channel error interrupts, and restart the channel if needed.
1259  */
1260 static void xilinx_dpdma_chan_err_task(unsigned long data)
1261 {
1262 	struct xilinx_dpdma_chan *chan = (struct xilinx_dpdma_chan *)data;
1263 	struct xilinx_dpdma_device *xdev = chan->xdev;
1264 	unsigned long flags;
1265 
1266 	/* Proceed error handling even when polling fails. */
1267 	xilinx_dpdma_chan_poll_no_ostand(chan);
1268 
1269 	xilinx_dpdma_chan_handle_err(chan);
1270 
1271 	dpdma_write(xdev->reg, XILINX_DPDMA_IEN,
1272 		    XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id);
1273 	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN,
1274 		    XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id);
1275 
1276 	spin_lock_irqsave(&chan->lock, flags);
1277 	xilinx_dpdma_chan_queue_transfer(chan);
1278 	spin_unlock_irqrestore(&chan->lock, flags);
1279 }
1280 
1281 static irqreturn_t xilinx_dpdma_irq_handler(int irq, void *data)
1282 {
1283 	struct xilinx_dpdma_device *xdev = data;
1284 	unsigned long mask;
1285 	unsigned int i;
1286 	u32 status;
1287 	u32 error;
1288 
1289 	status = dpdma_read(xdev->reg, XILINX_DPDMA_ISR);
1290 	error = dpdma_read(xdev->reg, XILINX_DPDMA_EISR);
1291 	if (!status && !error)
1292 		return IRQ_NONE;
1293 
1294 	dpdma_write(xdev->reg, XILINX_DPDMA_ISR, status);
1295 	dpdma_write(xdev->reg, XILINX_DPDMA_EISR, error);
1296 
1297 	if (status & XILINX_DPDMA_INTR_VSYNC) {
1298 		/*
1299 		 * There's a single VSYNC interrupt that needs to be processed
1300 		 * by each running channel to update the active descriptor.
1301 		 */
1302 		for (i = 0; i < ARRAY_SIZE(xdev->chan); i++) {
1303 			struct xilinx_dpdma_chan *chan = xdev->chan[i];
1304 
1305 			if (chan)
1306 				xilinx_dpdma_chan_vsync_irq(chan);
1307 		}
1308 	}
1309 
1310 	mask = FIELD_GET(XILINX_DPDMA_INTR_DESC_DONE_MASK, status);
1311 	if (mask) {
1312 		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
1313 			xilinx_dpdma_chan_done_irq(xdev->chan[i]);
1314 	}
1315 
1316 	mask = FIELD_GET(XILINX_DPDMA_INTR_NO_OSTAND_MASK, status);
1317 	if (mask) {
1318 		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
1319 			xilinx_dpdma_chan_notify_no_ostand(xdev->chan[i]);
1320 	}
1321 
1322 	mask = status & XILINX_DPDMA_INTR_ERR_ALL;
1323 	if (mask || error)
1324 		xilinx_dpdma_handle_err_irq(xdev, mask, error);
1325 
1326 	return IRQ_HANDLED;
1327 }
1328 
1329 /* -----------------------------------------------------------------------------
1330  * Initialization & Cleanup
1331  */
1332 
1333 static int xilinx_dpdma_chan_init(struct xilinx_dpdma_device *xdev,
1334 				  unsigned int chan_id)
1335 {
1336 	struct xilinx_dpdma_chan *chan;
1337 
1338 	chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
1339 	if (!chan)
1340 		return -ENOMEM;
1341 
1342 	chan->id = chan_id;
1343 	chan->reg = xdev->reg + XILINX_DPDMA_CH_BASE
1344 		  + XILINX_DPDMA_CH_OFFSET * chan->id;
1345 	chan->running = false;
1346 	chan->xdev = xdev;
1347 
1348 	spin_lock_init(&chan->lock);
1349 	init_waitqueue_head(&chan->wait_to_stop);
1350 
1351 	tasklet_init(&chan->err_task, xilinx_dpdma_chan_err_task,
1352 		     (unsigned long)chan);
1353 
1354 	chan->vchan.desc_free = xilinx_dpdma_chan_free_tx_desc;
1355 	vchan_init(&chan->vchan, &xdev->common);
1356 
1357 	xdev->chan[chan->id] = chan;
1358 
1359 	return 0;
1360 }
1361 
1362 static void xilinx_dpdma_chan_remove(struct xilinx_dpdma_chan *chan)
1363 {
1364 	if (!chan)
1365 		return;
1366 
1367 	tasklet_kill(&chan->err_task);
1368 	list_del(&chan->vchan.chan.device_node);
1369 }
1370 
1371 static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
1372 					    struct of_dma *ofdma)
1373 {
1374 	struct xilinx_dpdma_device *xdev = ofdma->of_dma_data;
1375 	uint32_t chan_id = dma_spec->args[0];
1376 
1377 	if (chan_id >= ARRAY_SIZE(xdev->chan))
1378 		return NULL;
1379 
1380 	if (!xdev->chan[chan_id])
1381 		return NULL;
1382 
1383 	return dma_get_slave_channel(&xdev->chan[chan_id]->vchan.chan);
1384 }
1385 
1386 static int xilinx_dpdma_probe(struct platform_device *pdev)
1387 {
1388 	struct xilinx_dpdma_device *xdev;
1389 	struct dma_device *ddev;
1390 	unsigned int i;
1391 	int ret;
1392 
1393 	xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
1394 	if (!xdev)
1395 		return -ENOMEM;
1396 
1397 	xdev->dev = &pdev->dev;
1398 	xdev->ext_addr = sizeof(dma_addr_t) > 4;
1399 
1400 	INIT_LIST_HEAD(&xdev->common.channels);
1401 
1402 	platform_set_drvdata(pdev, xdev);
1403 
1404 	xdev->axi_clk = devm_clk_get(xdev->dev, "axi_clk");
1405 	if (IS_ERR(xdev->axi_clk))
1406 		return PTR_ERR(xdev->axi_clk);
1407 
1408 	xdev->reg = devm_platform_ioremap_resource(pdev, 0);
1409 	if (IS_ERR(xdev->reg))
1410 		return PTR_ERR(xdev->reg);
1411 
1412 	xdev->irq = platform_get_irq(pdev, 0);
1413 	if (xdev->irq < 0) {
1414 		dev_err(xdev->dev, "failed to get platform irq\n");
1415 		return xdev->irq;
1416 	}
1417 
1418 	ret = request_irq(xdev->irq, xilinx_dpdma_irq_handler, IRQF_SHARED,
1419 			  dev_name(xdev->dev), xdev);
1420 	if (ret) {
1421 		dev_err(xdev->dev, "failed to request IRQ\n");
1422 		return ret;
1423 	}
1424 
1425 	ddev = &xdev->common;
1426 	ddev->dev = &pdev->dev;
1427 
1428 	dma_cap_set(DMA_SLAVE, ddev->cap_mask);
1429 	dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
1430 	dma_cap_set(DMA_INTERLEAVE, ddev->cap_mask);
1431 	dma_cap_set(DMA_REPEAT, ddev->cap_mask);
1432 	dma_cap_set(DMA_LOAD_EOT, ddev->cap_mask);
1433 	ddev->copy_align = fls(XILINX_DPDMA_ALIGN_BYTES - 1);
1434 
1435 	ddev->device_alloc_chan_resources = xilinx_dpdma_alloc_chan_resources;
1436 	ddev->device_free_chan_resources = xilinx_dpdma_free_chan_resources;
1437 	ddev->device_prep_interleaved_dma = xilinx_dpdma_prep_interleaved_dma;
1438 	/* TODO: Can we achieve better granularity ? */
1439 	ddev->device_tx_status = dma_cookie_status;
1440 	ddev->device_issue_pending = xilinx_dpdma_issue_pending;
1441 	ddev->device_config = xilinx_dpdma_config;
1442 	ddev->device_pause = xilinx_dpdma_pause;
1443 	ddev->device_resume = xilinx_dpdma_resume;
1444 	ddev->device_terminate_all = xilinx_dpdma_terminate_all;
1445 	ddev->device_synchronize = xilinx_dpdma_synchronize;
1446 	ddev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED);
1447 	ddev->directions = BIT(DMA_MEM_TO_DEV);
1448 	ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1449 
1450 	for (i = 0; i < ARRAY_SIZE(xdev->chan); ++i) {
1451 		ret = xilinx_dpdma_chan_init(xdev, i);
1452 		if (ret < 0) {
1453 			dev_err(xdev->dev, "failed to initialize channel %u\n",
1454 				i);
1455 			goto error;
1456 		}
1457 	}
1458 
1459 	ret = clk_prepare_enable(xdev->axi_clk);
1460 	if (ret) {
1461 		dev_err(xdev->dev, "failed to enable the axi clock\n");
1462 		goto error;
1463 	}
1464 
1465 	ret = dma_async_device_register(ddev);
1466 	if (ret) {
1467 		dev_err(xdev->dev, "failed to register the dma device\n");
1468 		goto error_dma_async;
1469 	}
1470 
1471 	ret = of_dma_controller_register(xdev->dev->of_node,
1472 					 of_dma_xilinx_xlate, ddev);
1473 	if (ret) {
1474 		dev_err(xdev->dev, "failed to register DMA to DT DMA helper\n");
1475 		goto error_of_dma;
1476 	}
1477 
1478 	xilinx_dpdma_enable_irq(xdev);
1479 
1480 	dev_info(&pdev->dev, "Xilinx DPDMA engine is probed\n");
1481 
1482 	return 0;
1483 
1484 error_of_dma:
1485 	dma_async_device_unregister(ddev);
1486 error_dma_async:
1487 	clk_disable_unprepare(xdev->axi_clk);
1488 error:
1489 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1490 		xilinx_dpdma_chan_remove(xdev->chan[i]);
1491 
1492 	free_irq(xdev->irq, xdev);
1493 
1494 	return ret;
1495 }
1496 
1497 static int xilinx_dpdma_remove(struct platform_device *pdev)
1498 {
1499 	struct xilinx_dpdma_device *xdev = platform_get_drvdata(pdev);
1500 	unsigned int i;
1501 
1502 	/* Start by disabling the IRQ to avoid races during cleanup. */
1503 	free_irq(xdev->irq, xdev);
1504 
1505 	xilinx_dpdma_disable_irq(xdev);
1506 	of_dma_controller_free(pdev->dev.of_node);
1507 	dma_async_device_unregister(&xdev->common);
1508 	clk_disable_unprepare(xdev->axi_clk);
1509 
1510 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1511 		xilinx_dpdma_chan_remove(xdev->chan[i]);
1512 
1513 	return 0;
1514 }
1515 
1516 static const struct of_device_id xilinx_dpdma_of_match[] = {
1517 	{ .compatible = "xlnx,zynqmp-dpdma",},
1518 	{ /* end of table */ },
1519 };
1520 MODULE_DEVICE_TABLE(of, xilinx_dpdma_of_match);
1521 
1522 static struct platform_driver xilinx_dpdma_driver = {
1523 	.probe			= xilinx_dpdma_probe,
1524 	.remove			= xilinx_dpdma_remove,
1525 	.driver			= {
1526 		.name		= "xilinx-zynqmp-dpdma",
1527 		.of_match_table	= xilinx_dpdma_of_match,
1528 	},
1529 };
1530 
1531 module_platform_driver(xilinx_dpdma_driver);
1532 
1533 MODULE_AUTHOR("Xilinx, Inc.");
1534 MODULE_DESCRIPTION("Xilinx ZynqMP DPDMA driver");
1535 MODULE_LICENSE("GPL v2");
1536