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/debugfs.h>
14 #include <linux/delay.h>
15 #include <linux/dmaengine.h>
16 #include <linux/dmapool.h>
17 #include <linux/interrupt.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_dma.h>
21 #include <linux/platform_device.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/spinlock.h>
25 #include <linux/wait.h>
26 
27 #include <dt-bindings/dma/xlnx-zynqmp-dpdma.h>
28 
29 #include "../dmaengine.h"
30 #include "../virt-dma.h"
31 
32 /* DPDMA registers */
33 #define XILINX_DPDMA_ERR_CTRL				0x000
34 #define XILINX_DPDMA_ISR				0x004
35 #define XILINX_DPDMA_IMR				0x008
36 #define XILINX_DPDMA_IEN				0x00c
37 #define XILINX_DPDMA_IDS				0x010
38 #define XILINX_DPDMA_INTR_DESC_DONE(n)			BIT((n) + 0)
39 #define XILINX_DPDMA_INTR_DESC_DONE_MASK		GENMASK(5, 0)
40 #define XILINX_DPDMA_INTR_NO_OSTAND(n)			BIT((n) + 6)
41 #define XILINX_DPDMA_INTR_NO_OSTAND_MASK		GENMASK(11, 6)
42 #define XILINX_DPDMA_INTR_AXI_ERR(n)			BIT((n) + 12)
43 #define XILINX_DPDMA_INTR_AXI_ERR_MASK			GENMASK(17, 12)
44 #define XILINX_DPDMA_INTR_DESC_ERR(n)			BIT((n) + 16)
45 #define XILINX_DPDMA_INTR_DESC_ERR_MASK			GENMASK(23, 18)
46 #define XILINX_DPDMA_INTR_WR_CMD_FIFO_FULL		BIT(24)
47 #define XILINX_DPDMA_INTR_WR_DATA_FIFO_FULL		BIT(25)
48 #define XILINX_DPDMA_INTR_AXI_4K_CROSS			BIT(26)
49 #define XILINX_DPDMA_INTR_VSYNC				BIT(27)
50 #define XILINX_DPDMA_INTR_CHAN_ERR_MASK			0x00041000
51 #define XILINX_DPDMA_INTR_CHAN_ERR			0x00fff000
52 #define XILINX_DPDMA_INTR_GLOBAL_ERR			0x07000000
53 #define XILINX_DPDMA_INTR_ERR_ALL			0x07fff000
54 #define XILINX_DPDMA_INTR_CHAN_MASK			0x00041041
55 #define XILINX_DPDMA_INTR_GLOBAL_MASK			0x0f000000
56 #define XILINX_DPDMA_INTR_ALL				0x0fffffff
57 #define XILINX_DPDMA_EISR				0x014
58 #define XILINX_DPDMA_EIMR				0x018
59 #define XILINX_DPDMA_EIEN				0x01c
60 #define XILINX_DPDMA_EIDS				0x020
61 #define XILINX_DPDMA_EINTR_INV_APB			BIT(0)
62 #define XILINX_DPDMA_EINTR_RD_AXI_ERR(n)		BIT((n) + 1)
63 #define XILINX_DPDMA_EINTR_RD_AXI_ERR_MASK		GENMASK(6, 1)
64 #define XILINX_DPDMA_EINTR_PRE_ERR(n)			BIT((n) + 7)
65 #define XILINX_DPDMA_EINTR_PRE_ERR_MASK			GENMASK(12, 7)
66 #define XILINX_DPDMA_EINTR_CRC_ERR(n)			BIT((n) + 13)
67 #define XILINX_DPDMA_EINTR_CRC_ERR_MASK			GENMASK(18, 13)
68 #define XILINX_DPDMA_EINTR_WR_AXI_ERR(n)		BIT((n) + 19)
69 #define XILINX_DPDMA_EINTR_WR_AXI_ERR_MASK		GENMASK(24, 19)
70 #define XILINX_DPDMA_EINTR_DESC_DONE_ERR(n)		BIT((n) + 25)
71 #define XILINX_DPDMA_EINTR_DESC_DONE_ERR_MASK		GENMASK(30, 25)
72 #define XILINX_DPDMA_EINTR_RD_CMD_FIFO_FULL		BIT(32)
73 #define XILINX_DPDMA_EINTR_CHAN_ERR_MASK		0x02082082
74 #define XILINX_DPDMA_EINTR_CHAN_ERR			0x7ffffffe
75 #define XILINX_DPDMA_EINTR_GLOBAL_ERR			0x80000001
76 #define XILINX_DPDMA_EINTR_ALL				0xffffffff
77 #define XILINX_DPDMA_CNTL				0x100
78 #define XILINX_DPDMA_GBL				0x104
79 #define XILINX_DPDMA_GBL_TRIG_MASK(n)			((n) << 0)
80 #define XILINX_DPDMA_GBL_RETRIG_MASK(n)			((n) << 6)
81 #define XILINX_DPDMA_ALC0_CNTL				0x108
82 #define XILINX_DPDMA_ALC0_STATUS			0x10c
83 #define XILINX_DPDMA_ALC0_MAX				0x110
84 #define XILINX_DPDMA_ALC0_MIN				0x114
85 #define XILINX_DPDMA_ALC0_ACC				0x118
86 #define XILINX_DPDMA_ALC0_ACC_TRAN			0x11c
87 #define XILINX_DPDMA_ALC1_CNTL				0x120
88 #define XILINX_DPDMA_ALC1_STATUS			0x124
89 #define XILINX_DPDMA_ALC1_MAX				0x128
90 #define XILINX_DPDMA_ALC1_MIN				0x12c
91 #define XILINX_DPDMA_ALC1_ACC				0x130
92 #define XILINX_DPDMA_ALC1_ACC_TRAN			0x134
93 
94 /* Channel register */
95 #define XILINX_DPDMA_CH_BASE				0x200
96 #define XILINX_DPDMA_CH_OFFSET				0x100
97 #define XILINX_DPDMA_CH_DESC_START_ADDRE		0x000
98 #define XILINX_DPDMA_CH_DESC_START_ADDRE_MASK		GENMASK(15, 0)
99 #define XILINX_DPDMA_CH_DESC_START_ADDR			0x004
100 #define XILINX_DPDMA_CH_DESC_NEXT_ADDRE			0x008
101 #define XILINX_DPDMA_CH_DESC_NEXT_ADDR			0x00c
102 #define XILINX_DPDMA_CH_PYLD_CUR_ADDRE			0x010
103 #define XILINX_DPDMA_CH_PYLD_CUR_ADDR			0x014
104 #define XILINX_DPDMA_CH_CNTL				0x018
105 #define XILINX_DPDMA_CH_CNTL_ENABLE			BIT(0)
106 #define XILINX_DPDMA_CH_CNTL_PAUSE			BIT(1)
107 #define XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK		GENMASK(5, 2)
108 #define XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK		GENMASK(9, 6)
109 #define XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK		GENMASK(13, 10)
110 #define XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS		11
111 #define XILINX_DPDMA_CH_STATUS				0x01c
112 #define XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK		GENMASK(24, 21)
113 #define XILINX_DPDMA_CH_VDO				0x020
114 #define XILINX_DPDMA_CH_PYLD_SZ				0x024
115 #define XILINX_DPDMA_CH_DESC_ID				0x028
116 
117 /* DPDMA descriptor fields */
118 #define XILINX_DPDMA_DESC_CONTROL_PREEMBLE		0xa5
119 #define XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR		BIT(8)
120 #define XILINX_DPDMA_DESC_CONTROL_DESC_UPDATE		BIT(9)
121 #define XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE		BIT(10)
122 #define XILINX_DPDMA_DESC_CONTROL_FRAG_MODE		BIT(18)
123 #define XILINX_DPDMA_DESC_CONTROL_LAST			BIT(19)
124 #define XILINX_DPDMA_DESC_CONTROL_ENABLE_CRC		BIT(20)
125 #define XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME		BIT(21)
126 #define XILINX_DPDMA_DESC_ID_MASK			GENMASK(15, 0)
127 #define XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK	GENMASK(17, 0)
128 #define XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK	GENMASK(31, 18)
129 #define XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK	GENMASK(15, 0)
130 #define XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK	GENMASK(31, 16)
131 
132 #define XILINX_DPDMA_ALIGN_BYTES			256
133 #define XILINX_DPDMA_LINESIZE_ALIGN_BITS		128
134 
135 #define XILINX_DPDMA_NUM_CHAN				6
136 
137 struct xilinx_dpdma_chan;
138 
139 /**
140  * struct xilinx_dpdma_hw_desc - DPDMA hardware descriptor
141  * @control: control configuration field
142  * @desc_id: descriptor ID
143  * @xfer_size: transfer size
144  * @hsize_stride: horizontal size and stride
145  * @timestamp_lsb: LSB of time stamp
146  * @timestamp_msb: MSB of time stamp
147  * @addr_ext: upper 16 bit of 48 bit address (next_desc and src_addr)
148  * @next_desc: next descriptor 32 bit address
149  * @src_addr: payload source address (1st page, 32 LSB)
150  * @addr_ext_23: payload source address (3nd and 3rd pages, 16 LSBs)
151  * @addr_ext_45: payload source address (4th and 5th pages, 16 LSBs)
152  * @src_addr2: payload source address (2nd page, 32 LSB)
153  * @src_addr3: payload source address (3rd page, 32 LSB)
154  * @src_addr4: payload source address (4th page, 32 LSB)
155  * @src_addr5: payload source address (5th page, 32 LSB)
156  * @crc: descriptor CRC
157  */
158 struct xilinx_dpdma_hw_desc {
159 	u32 control;
160 	u32 desc_id;
161 	u32 xfer_size;
162 	u32 hsize_stride;
163 	u32 timestamp_lsb;
164 	u32 timestamp_msb;
165 	u32 addr_ext;
166 	u32 next_desc;
167 	u32 src_addr;
168 	u32 addr_ext_23;
169 	u32 addr_ext_45;
170 	u32 src_addr2;
171 	u32 src_addr3;
172 	u32 src_addr4;
173 	u32 src_addr5;
174 	u32 crc;
175 } __aligned(XILINX_DPDMA_ALIGN_BYTES);
176 
177 /**
178  * struct xilinx_dpdma_sw_desc - DPDMA software descriptor
179  * @hw: DPDMA hardware descriptor
180  * @node: list node for software descriptors
181  * @dma_addr: DMA address of the software descriptor
182  */
183 struct xilinx_dpdma_sw_desc {
184 	struct xilinx_dpdma_hw_desc hw;
185 	struct list_head node;
186 	dma_addr_t dma_addr;
187 };
188 
189 /**
190  * struct xilinx_dpdma_tx_desc - DPDMA transaction descriptor
191  * @vdesc: virtual DMA descriptor
192  * @chan: DMA channel
193  * @descriptors: list of software descriptors
194  * @error: an error has been detected with this descriptor
195  */
196 struct xilinx_dpdma_tx_desc {
197 	struct virt_dma_desc vdesc;
198 	struct xilinx_dpdma_chan *chan;
199 	struct list_head descriptors;
200 	bool error;
201 };
202 
203 #define to_dpdma_tx_desc(_desc) \
204 	container_of(_desc, struct xilinx_dpdma_tx_desc, vdesc)
205 
206 /**
207  * struct xilinx_dpdma_chan - DPDMA channel
208  * @vchan: virtual DMA channel
209  * @reg: register base address
210  * @id: channel ID
211  * @wait_to_stop: queue to wait for outstanding transacitons before stopping
212  * @running: true if the channel is running
213  * @first_frame: flag for the first frame of stream
214  * @video_group: flag if multi-channel operation is needed for video channels
215  * @lock: lock to access struct xilinx_dpdma_chan
216  * @desc_pool: descriptor allocation pool
217  * @err_task: error IRQ bottom half handler
218  * @desc: References to descriptors being processed
219  * @desc.pending: Descriptor schedule to the hardware, pending execution
220  * @desc.active: Descriptor being executed by the hardware
221  * @xdev: DPDMA device
222  */
223 struct xilinx_dpdma_chan {
224 	struct virt_dma_chan vchan;
225 	void __iomem *reg;
226 	unsigned int id;
227 
228 	wait_queue_head_t wait_to_stop;
229 	bool running;
230 	bool first_frame;
231 	bool video_group;
232 
233 	spinlock_t lock; /* lock to access struct xilinx_dpdma_chan */
234 	struct dma_pool *desc_pool;
235 	struct tasklet_struct err_task;
236 
237 	struct {
238 		struct xilinx_dpdma_tx_desc *pending;
239 		struct xilinx_dpdma_tx_desc *active;
240 	} desc;
241 
242 	struct xilinx_dpdma_device *xdev;
243 };
244 
245 #define to_xilinx_chan(_chan) \
246 	container_of(_chan, struct xilinx_dpdma_chan, vchan.chan)
247 
248 /**
249  * struct xilinx_dpdma_device - DPDMA device
250  * @common: generic dma device structure
251  * @reg: register base address
252  * @dev: generic device structure
253  * @irq: the interrupt number
254  * @axi_clk: axi clock
255  * @chan: DPDMA channels
256  * @ext_addr: flag for 64 bit system (48 bit addressing)
257  */
258 struct xilinx_dpdma_device {
259 	struct dma_device common;
260 	void __iomem *reg;
261 	struct device *dev;
262 	int irq;
263 
264 	struct clk *axi_clk;
265 	struct xilinx_dpdma_chan *chan[XILINX_DPDMA_NUM_CHAN];
266 
267 	bool ext_addr;
268 };
269 
270 /* -----------------------------------------------------------------------------
271  * DebugFS
272  */
273 
274 #ifdef CONFIG_DEBUG_FS
275 
276 #define XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE	32
277 #define XILINX_DPDMA_DEBUGFS_UINT16_MAX_STR	"65535"
278 
279 /* Match xilinx_dpdma_testcases vs dpdma_debugfs_reqs[] entry */
280 enum xilinx_dpdma_testcases {
281 	DPDMA_TC_INTR_DONE,
282 	DPDMA_TC_NONE
283 };
284 
285 struct xilinx_dpdma_debugfs {
286 	enum xilinx_dpdma_testcases testcase;
287 	u16 xilinx_dpdma_irq_done_count;
288 	unsigned int chan_id;
289 };
290 
291 static struct xilinx_dpdma_debugfs dpdma_debugfs;
292 struct xilinx_dpdma_debugfs_request {
293 	const char *name;
294 	enum xilinx_dpdma_testcases tc;
295 	ssize_t (*read)(char *buf);
296 	int (*write)(char *args);
297 };
298 
299 static void xilinx_dpdma_debugfs_desc_done_irq(struct xilinx_dpdma_chan *chan)
300 {
301 	if (chan->id == dpdma_debugfs.chan_id)
302 		dpdma_debugfs.xilinx_dpdma_irq_done_count++;
303 }
304 
305 static ssize_t xilinx_dpdma_debugfs_desc_done_irq_read(char *buf)
306 {
307 	size_t out_str_len;
308 
309 	dpdma_debugfs.testcase = DPDMA_TC_NONE;
310 
311 	out_str_len = strlen(XILINX_DPDMA_DEBUGFS_UINT16_MAX_STR);
312 	out_str_len = min_t(size_t, XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE,
313 			    out_str_len);
314 	snprintf(buf, out_str_len, "%d",
315 		 dpdma_debugfs.xilinx_dpdma_irq_done_count);
316 
317 	return 0;
318 }
319 
320 static int xilinx_dpdma_debugfs_desc_done_irq_write(char *args)
321 {
322 	char *arg;
323 	int ret;
324 	u32 id;
325 
326 	arg = strsep(&args, " ");
327 	if (!arg || strncasecmp(arg, "start", 5))
328 		return -EINVAL;
329 
330 	arg = strsep(&args, " ");
331 	if (!arg)
332 		return -EINVAL;
333 
334 	ret = kstrtou32(arg, 0, &id);
335 	if (ret < 0)
336 		return ret;
337 
338 	if (id < ZYNQMP_DPDMA_VIDEO0 || id > ZYNQMP_DPDMA_AUDIO1)
339 		return -EINVAL;
340 
341 	dpdma_debugfs.testcase = DPDMA_TC_INTR_DONE;
342 	dpdma_debugfs.xilinx_dpdma_irq_done_count = 0;
343 	dpdma_debugfs.chan_id = id;
344 
345 	return 0;
346 }
347 
348 /* Match xilinx_dpdma_testcases vs dpdma_debugfs_reqs[] entry */
349 static struct xilinx_dpdma_debugfs_request dpdma_debugfs_reqs[] = {
350 	{
351 		.name = "DESCRIPTOR_DONE_INTR",
352 		.tc = DPDMA_TC_INTR_DONE,
353 		.read = xilinx_dpdma_debugfs_desc_done_irq_read,
354 		.write = xilinx_dpdma_debugfs_desc_done_irq_write,
355 	},
356 };
357 
358 static ssize_t xilinx_dpdma_debugfs_read(struct file *f, char __user *buf,
359 					 size_t size, loff_t *pos)
360 {
361 	enum xilinx_dpdma_testcases testcase;
362 	char *kern_buff;
363 	int ret = 0;
364 
365 	if (*pos != 0 || size <= 0)
366 		return -EINVAL;
367 
368 	kern_buff = kzalloc(XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE, GFP_KERNEL);
369 	if (!kern_buff) {
370 		dpdma_debugfs.testcase = DPDMA_TC_NONE;
371 		return -ENOMEM;
372 	}
373 
374 	testcase = READ_ONCE(dpdma_debugfs.testcase);
375 	if (testcase != DPDMA_TC_NONE) {
376 		ret = dpdma_debugfs_reqs[testcase].read(kern_buff);
377 		if (ret < 0)
378 			goto done;
379 	} else {
380 		strlcpy(kern_buff, "No testcase executed",
381 			XILINX_DPDMA_DEBUGFS_READ_MAX_SIZE);
382 	}
383 
384 	size = min(size, strlen(kern_buff));
385 	if (copy_to_user(buf, kern_buff, size))
386 		ret = -EFAULT;
387 
388 done:
389 	kfree(kern_buff);
390 	if (ret)
391 		return ret;
392 
393 	*pos = size + 1;
394 	return size;
395 }
396 
397 static ssize_t xilinx_dpdma_debugfs_write(struct file *f,
398 					  const char __user *buf, size_t size,
399 					  loff_t *pos)
400 {
401 	char *kern_buff, *kern_buff_start;
402 	char *testcase;
403 	unsigned int i;
404 	int ret;
405 
406 	if (*pos != 0 || size <= 0)
407 		return -EINVAL;
408 
409 	/* Supporting single instance of test as of now. */
410 	if (dpdma_debugfs.testcase != DPDMA_TC_NONE)
411 		return -EBUSY;
412 
413 	kern_buff = kzalloc(size, GFP_KERNEL);
414 	if (!kern_buff)
415 		return -ENOMEM;
416 	kern_buff_start = kern_buff;
417 
418 	ret = strncpy_from_user(kern_buff, buf, size);
419 	if (ret < 0)
420 		goto done;
421 
422 	/* Read the testcase name from a user request. */
423 	testcase = strsep(&kern_buff, " ");
424 
425 	for (i = 0; i < ARRAY_SIZE(dpdma_debugfs_reqs); i++) {
426 		if (!strcasecmp(testcase, dpdma_debugfs_reqs[i].name))
427 			break;
428 	}
429 
430 	if (i == ARRAY_SIZE(dpdma_debugfs_reqs)) {
431 		ret = -EINVAL;
432 		goto done;
433 	}
434 
435 	ret = dpdma_debugfs_reqs[i].write(kern_buff);
436 	if (ret < 0)
437 		goto done;
438 
439 	ret = size;
440 
441 done:
442 	kfree(kern_buff_start);
443 	return ret;
444 }
445 
446 static const struct file_operations fops_xilinx_dpdma_dbgfs = {
447 	.owner = THIS_MODULE,
448 	.read = xilinx_dpdma_debugfs_read,
449 	.write = xilinx_dpdma_debugfs_write,
450 };
451 
452 static void xilinx_dpdma_debugfs_init(struct xilinx_dpdma_device *xdev)
453 {
454 	struct dentry *dent;
455 
456 	dpdma_debugfs.testcase = DPDMA_TC_NONE;
457 
458 	dent = debugfs_create_file("testcase", 0444, xdev->common.dbg_dev_root,
459 				   NULL, &fops_xilinx_dpdma_dbgfs);
460 	if (IS_ERR(dent))
461 		dev_err(xdev->dev, "Failed to create debugfs testcase file\n");
462 }
463 
464 #else
465 static void xilinx_dpdma_debugfs_init(struct xilinx_dpdma_device *xdev)
466 {
467 }
468 
469 static void xilinx_dpdma_debugfs_desc_done_irq(struct xilinx_dpdma_chan *chan)
470 {
471 }
472 #endif /* CONFIG_DEBUG_FS */
473 
474 /* -----------------------------------------------------------------------------
475  * I/O Accessors
476  */
477 
478 static inline u32 dpdma_read(void __iomem *base, u32 offset)
479 {
480 	return ioread32(base + offset);
481 }
482 
483 static inline void dpdma_write(void __iomem *base, u32 offset, u32 val)
484 {
485 	iowrite32(val, base + offset);
486 }
487 
488 static inline void dpdma_clr(void __iomem *base, u32 offset, u32 clr)
489 {
490 	dpdma_write(base, offset, dpdma_read(base, offset) & ~clr);
491 }
492 
493 static inline void dpdma_set(void __iomem *base, u32 offset, u32 set)
494 {
495 	dpdma_write(base, offset, dpdma_read(base, offset) | set);
496 }
497 
498 /* -----------------------------------------------------------------------------
499  * Descriptor Operations
500  */
501 
502 /**
503  * xilinx_dpdma_sw_desc_set_dma_addrs - Set DMA addresses in the descriptor
504  * @xdev: DPDMA device
505  * @sw_desc: The software descriptor in which to set DMA addresses
506  * @prev: The previous descriptor
507  * @dma_addr: array of dma addresses
508  * @num_src_addr: number of addresses in @dma_addr
509  *
510  * Set all the DMA addresses in the hardware descriptor corresponding to @dev
511  * from @dma_addr. If a previous descriptor is specified in @prev, its next
512  * descriptor DMA address is set to the DMA address of @sw_desc. @prev may be
513  * identical to @sw_desc for cyclic transfers.
514  */
515 static void xilinx_dpdma_sw_desc_set_dma_addrs(struct xilinx_dpdma_device *xdev,
516 					       struct xilinx_dpdma_sw_desc *sw_desc,
517 					       struct xilinx_dpdma_sw_desc *prev,
518 					       dma_addr_t dma_addr[],
519 					       unsigned int num_src_addr)
520 {
521 	struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
522 	unsigned int i;
523 
524 	hw_desc->src_addr = lower_32_bits(dma_addr[0]);
525 	if (xdev->ext_addr)
526 		hw_desc->addr_ext |=
527 			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_SRC_ADDR_MASK,
528 				   upper_32_bits(dma_addr[0]));
529 
530 	for (i = 1; i < num_src_addr; i++) {
531 		u32 *addr = &hw_desc->src_addr2;
532 
533 		addr[i-1] = lower_32_bits(dma_addr[i]);
534 
535 		if (xdev->ext_addr) {
536 			u32 *addr_ext = &hw_desc->addr_ext_23;
537 			u32 addr_msb;
538 
539 			addr_msb = upper_32_bits(dma_addr[i]) & GENMASK(15, 0);
540 			addr_msb <<= 16 * ((i - 1) % 2);
541 			addr_ext[(i - 1) / 2] |= addr_msb;
542 		}
543 	}
544 
545 	if (!prev)
546 		return;
547 
548 	prev->hw.next_desc = lower_32_bits(sw_desc->dma_addr);
549 	if (xdev->ext_addr)
550 		prev->hw.addr_ext |=
551 			FIELD_PREP(XILINX_DPDMA_DESC_ADDR_EXT_NEXT_ADDR_MASK,
552 				   upper_32_bits(sw_desc->dma_addr));
553 }
554 
555 /**
556  * xilinx_dpdma_chan_alloc_sw_desc - Allocate a software descriptor
557  * @chan: DPDMA channel
558  *
559  * Allocate a software descriptor from the channel's descriptor pool.
560  *
561  * Return: a software descriptor or NULL.
562  */
563 static struct xilinx_dpdma_sw_desc *
564 xilinx_dpdma_chan_alloc_sw_desc(struct xilinx_dpdma_chan *chan)
565 {
566 	struct xilinx_dpdma_sw_desc *sw_desc;
567 	dma_addr_t dma_addr;
568 
569 	sw_desc = dma_pool_zalloc(chan->desc_pool, GFP_ATOMIC, &dma_addr);
570 	if (!sw_desc)
571 		return NULL;
572 
573 	sw_desc->dma_addr = dma_addr;
574 
575 	return sw_desc;
576 }
577 
578 /**
579  * xilinx_dpdma_chan_free_sw_desc - Free a software descriptor
580  * @chan: DPDMA channel
581  * @sw_desc: software descriptor to free
582  *
583  * Free a software descriptor from the channel's descriptor pool.
584  */
585 static void
586 xilinx_dpdma_chan_free_sw_desc(struct xilinx_dpdma_chan *chan,
587 			       struct xilinx_dpdma_sw_desc *sw_desc)
588 {
589 	dma_pool_free(chan->desc_pool, sw_desc, sw_desc->dma_addr);
590 }
591 
592 /**
593  * xilinx_dpdma_chan_dump_tx_desc - Dump a tx descriptor
594  * @chan: DPDMA channel
595  * @tx_desc: tx descriptor to dump
596  *
597  * Dump contents of a tx descriptor
598  */
599 static void xilinx_dpdma_chan_dump_tx_desc(struct xilinx_dpdma_chan *chan,
600 					   struct xilinx_dpdma_tx_desc *tx_desc)
601 {
602 	struct xilinx_dpdma_sw_desc *sw_desc;
603 	struct device *dev = chan->xdev->dev;
604 	unsigned int i = 0;
605 
606 	dev_dbg(dev, "------- TX descriptor dump start -------\n");
607 	dev_dbg(dev, "------- channel ID = %d -------\n", chan->id);
608 
609 	list_for_each_entry(sw_desc, &tx_desc->descriptors, node) {
610 		struct xilinx_dpdma_hw_desc *hw_desc = &sw_desc->hw;
611 
612 		dev_dbg(dev, "------- HW descriptor %d -------\n", i++);
613 		dev_dbg(dev, "descriptor DMA addr: %pad\n", &sw_desc->dma_addr);
614 		dev_dbg(dev, "control: 0x%08x\n", hw_desc->control);
615 		dev_dbg(dev, "desc_id: 0x%08x\n", hw_desc->desc_id);
616 		dev_dbg(dev, "xfer_size: 0x%08x\n", hw_desc->xfer_size);
617 		dev_dbg(dev, "hsize_stride: 0x%08x\n", hw_desc->hsize_stride);
618 		dev_dbg(dev, "timestamp_lsb: 0x%08x\n", hw_desc->timestamp_lsb);
619 		dev_dbg(dev, "timestamp_msb: 0x%08x\n", hw_desc->timestamp_msb);
620 		dev_dbg(dev, "addr_ext: 0x%08x\n", hw_desc->addr_ext);
621 		dev_dbg(dev, "next_desc: 0x%08x\n", hw_desc->next_desc);
622 		dev_dbg(dev, "src_addr: 0x%08x\n", hw_desc->src_addr);
623 		dev_dbg(dev, "addr_ext_23: 0x%08x\n", hw_desc->addr_ext_23);
624 		dev_dbg(dev, "addr_ext_45: 0x%08x\n", hw_desc->addr_ext_45);
625 		dev_dbg(dev, "src_addr2: 0x%08x\n", hw_desc->src_addr2);
626 		dev_dbg(dev, "src_addr3: 0x%08x\n", hw_desc->src_addr3);
627 		dev_dbg(dev, "src_addr4: 0x%08x\n", hw_desc->src_addr4);
628 		dev_dbg(dev, "src_addr5: 0x%08x\n", hw_desc->src_addr5);
629 		dev_dbg(dev, "crc: 0x%08x\n", hw_desc->crc);
630 	}
631 
632 	dev_dbg(dev, "------- TX descriptor dump end -------\n");
633 }
634 
635 /**
636  * xilinx_dpdma_chan_alloc_tx_desc - Allocate a transaction descriptor
637  * @chan: DPDMA channel
638  *
639  * Allocate a tx descriptor.
640  *
641  * Return: a tx descriptor or NULL.
642  */
643 static struct xilinx_dpdma_tx_desc *
644 xilinx_dpdma_chan_alloc_tx_desc(struct xilinx_dpdma_chan *chan)
645 {
646 	struct xilinx_dpdma_tx_desc *tx_desc;
647 
648 	tx_desc = kzalloc(sizeof(*tx_desc), GFP_NOWAIT);
649 	if (!tx_desc)
650 		return NULL;
651 
652 	INIT_LIST_HEAD(&tx_desc->descriptors);
653 	tx_desc->chan = chan;
654 	tx_desc->error = false;
655 
656 	return tx_desc;
657 }
658 
659 /**
660  * xilinx_dpdma_chan_free_tx_desc - Free a virtual DMA descriptor
661  * @vdesc: virtual DMA descriptor
662  *
663  * Free the virtual DMA descriptor @vdesc including its software descriptors.
664  */
665 static void xilinx_dpdma_chan_free_tx_desc(struct virt_dma_desc *vdesc)
666 {
667 	struct xilinx_dpdma_sw_desc *sw_desc, *next;
668 	struct xilinx_dpdma_tx_desc *desc;
669 
670 	if (!vdesc)
671 		return;
672 
673 	desc = to_dpdma_tx_desc(vdesc);
674 
675 	list_for_each_entry_safe(sw_desc, next, &desc->descriptors, node) {
676 		list_del(&sw_desc->node);
677 		xilinx_dpdma_chan_free_sw_desc(desc->chan, sw_desc);
678 	}
679 
680 	kfree(desc);
681 }
682 
683 /**
684  * xilinx_dpdma_chan_prep_interleaved_dma - Prepare an interleaved dma
685  *					    descriptor
686  * @chan: DPDMA channel
687  * @xt: dma interleaved template
688  *
689  * Prepare a tx descriptor including internal software/hardware descriptors
690  * based on @xt.
691  *
692  * Return: A DPDMA TX descriptor on success, or NULL.
693  */
694 static struct xilinx_dpdma_tx_desc *
695 xilinx_dpdma_chan_prep_interleaved_dma(struct xilinx_dpdma_chan *chan,
696 				       struct dma_interleaved_template *xt)
697 {
698 	struct xilinx_dpdma_tx_desc *tx_desc;
699 	struct xilinx_dpdma_sw_desc *sw_desc;
700 	struct xilinx_dpdma_hw_desc *hw_desc;
701 	size_t hsize = xt->sgl[0].size;
702 	size_t stride = hsize + xt->sgl[0].icg;
703 
704 	if (!IS_ALIGNED(xt->src_start, XILINX_DPDMA_ALIGN_BYTES)) {
705 		dev_err(chan->xdev->dev, "buffer should be aligned at %d B\n",
706 			XILINX_DPDMA_ALIGN_BYTES);
707 		return NULL;
708 	}
709 
710 	tx_desc = xilinx_dpdma_chan_alloc_tx_desc(chan);
711 	if (!tx_desc)
712 		return NULL;
713 
714 	sw_desc = xilinx_dpdma_chan_alloc_sw_desc(chan);
715 	if (!sw_desc) {
716 		xilinx_dpdma_chan_free_tx_desc(&tx_desc->vdesc);
717 		return NULL;
718 	}
719 
720 	xilinx_dpdma_sw_desc_set_dma_addrs(chan->xdev, sw_desc, sw_desc,
721 					   &xt->src_start, 1);
722 
723 	hw_desc = &sw_desc->hw;
724 	hsize = ALIGN(hsize, XILINX_DPDMA_LINESIZE_ALIGN_BITS / 8);
725 	hw_desc->xfer_size = hsize * xt->numf;
726 	hw_desc->hsize_stride =
727 		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_HSIZE_MASK, hsize) |
728 		FIELD_PREP(XILINX_DPDMA_DESC_HSIZE_STRIDE_STRIDE_MASK,
729 			   stride / 16);
730 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_PREEMBLE;
731 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_COMPLETE_INTR;
732 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_IGNORE_DONE;
733 	hw_desc->control |= XILINX_DPDMA_DESC_CONTROL_LAST_OF_FRAME;
734 
735 	list_add_tail(&sw_desc->node, &tx_desc->descriptors);
736 
737 	return tx_desc;
738 }
739 
740 /* -----------------------------------------------------------------------------
741  * DPDMA Channel Operations
742  */
743 
744 /**
745  * xilinx_dpdma_chan_enable - Enable the channel
746  * @chan: DPDMA channel
747  *
748  * Enable the channel and its interrupts. Set the QoS values for video class.
749  */
750 static void xilinx_dpdma_chan_enable(struct xilinx_dpdma_chan *chan)
751 {
752 	u32 reg;
753 
754 	reg = (XILINX_DPDMA_INTR_CHAN_MASK << chan->id)
755 	    | XILINX_DPDMA_INTR_GLOBAL_MASK;
756 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
757 	reg = (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id)
758 	    | XILINX_DPDMA_INTR_GLOBAL_ERR;
759 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
760 
761 	reg = XILINX_DPDMA_CH_CNTL_ENABLE
762 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_WR_MASK,
763 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
764 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DSCR_RD_MASK,
765 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS)
766 	    | FIELD_PREP(XILINX_DPDMA_CH_CNTL_QOS_DATA_RD_MASK,
767 			 XILINX_DPDMA_CH_CNTL_QOS_VID_CLASS);
768 	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, reg);
769 }
770 
771 /**
772  * xilinx_dpdma_chan_disable - Disable the channel
773  * @chan: DPDMA channel
774  *
775  * Disable the channel and its interrupts.
776  */
777 static void xilinx_dpdma_chan_disable(struct xilinx_dpdma_chan *chan)
778 {
779 	u32 reg;
780 
781 	reg = XILINX_DPDMA_INTR_CHAN_MASK << chan->id;
782 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN, reg);
783 	reg = XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id;
784 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_EIEN, reg);
785 
786 	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_ENABLE);
787 }
788 
789 /**
790  * xilinx_dpdma_chan_pause - Pause the channel
791  * @chan: DPDMA channel
792  *
793  * Pause the channel.
794  */
795 static void xilinx_dpdma_chan_pause(struct xilinx_dpdma_chan *chan)
796 {
797 	dpdma_set(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
798 }
799 
800 /**
801  * xilinx_dpdma_chan_unpause - Unpause the channel
802  * @chan: DPDMA channel
803  *
804  * Unpause the channel.
805  */
806 static void xilinx_dpdma_chan_unpause(struct xilinx_dpdma_chan *chan)
807 {
808 	dpdma_clr(chan->reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_PAUSE);
809 }
810 
811 static u32 xilinx_dpdma_chan_video_group_ready(struct xilinx_dpdma_chan *chan)
812 {
813 	struct xilinx_dpdma_device *xdev = chan->xdev;
814 	u32 channels = 0;
815 	unsigned int i;
816 
817 	for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
818 		if (xdev->chan[i]->video_group && !xdev->chan[i]->running)
819 			return 0;
820 
821 		if (xdev->chan[i]->video_group)
822 			channels |= BIT(i);
823 	}
824 
825 	return channels;
826 }
827 
828 /**
829  * xilinx_dpdma_chan_queue_transfer - Queue the next transfer
830  * @chan: DPDMA channel
831  *
832  * Queue the next descriptor, if any, to the hardware. If the channel is
833  * stopped, start it first. Otherwise retrigger it with the next descriptor.
834  */
835 static void xilinx_dpdma_chan_queue_transfer(struct xilinx_dpdma_chan *chan)
836 {
837 	struct xilinx_dpdma_device *xdev = chan->xdev;
838 	struct xilinx_dpdma_sw_desc *sw_desc;
839 	struct xilinx_dpdma_tx_desc *desc;
840 	struct virt_dma_desc *vdesc;
841 	u32 reg, channels;
842 
843 	lockdep_assert_held(&chan->lock);
844 
845 	if (chan->desc.pending)
846 		return;
847 
848 	if (!chan->running) {
849 		xilinx_dpdma_chan_unpause(chan);
850 		xilinx_dpdma_chan_enable(chan);
851 		chan->first_frame = true;
852 		chan->running = true;
853 	}
854 
855 	if (chan->video_group)
856 		channels = xilinx_dpdma_chan_video_group_ready(chan);
857 	else
858 		channels = BIT(chan->id);
859 
860 	if (!channels)
861 		return;
862 
863 	vdesc = vchan_next_desc(&chan->vchan);
864 	if (!vdesc)
865 		return;
866 
867 	desc = to_dpdma_tx_desc(vdesc);
868 	chan->desc.pending = desc;
869 	list_del(&desc->vdesc.node);
870 
871 	/*
872 	 * Assign the cookie to descriptors in this transaction. Only 16 bit
873 	 * will be used, but it should be enough.
874 	 */
875 	list_for_each_entry(sw_desc, &desc->descriptors, node)
876 		sw_desc->hw.desc_id = desc->vdesc.tx.cookie;
877 
878 	sw_desc = list_first_entry(&desc->descriptors,
879 				   struct xilinx_dpdma_sw_desc, node);
880 	dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR,
881 		    lower_32_bits(sw_desc->dma_addr));
882 	if (xdev->ext_addr)
883 		dpdma_write(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE,
884 			    FIELD_PREP(XILINX_DPDMA_CH_DESC_START_ADDRE_MASK,
885 				       upper_32_bits(sw_desc->dma_addr)));
886 
887 	if (chan->first_frame)
888 		reg = XILINX_DPDMA_GBL_TRIG_MASK(channels);
889 	else
890 		reg = XILINX_DPDMA_GBL_RETRIG_MASK(channels);
891 
892 	chan->first_frame = false;
893 
894 	dpdma_write(xdev->reg, XILINX_DPDMA_GBL, reg);
895 }
896 
897 /**
898  * xilinx_dpdma_chan_ostand - Number of outstanding transactions
899  * @chan: DPDMA channel
900  *
901  * Read and return the number of outstanding transactions from register.
902  *
903  * Return: Number of outstanding transactions from the status register.
904  */
905 static u32 xilinx_dpdma_chan_ostand(struct xilinx_dpdma_chan *chan)
906 {
907 	return FIELD_GET(XILINX_DPDMA_CH_STATUS_OTRAN_CNT_MASK,
908 			 dpdma_read(chan->reg, XILINX_DPDMA_CH_STATUS));
909 }
910 
911 /**
912  * xilinx_dpdma_chan_no_ostand - Notify no outstanding transaction event
913  * @chan: DPDMA channel
914  *
915  * Notify waiters for no outstanding event, so waiters can stop the channel
916  * safely. This function is supposed to be called when 'no outstanding'
917  * interrupt is generated. The 'no outstanding' interrupt is disabled and
918  * should be re-enabled when this event is handled. If the channel status
919  * register still shows some number of outstanding transactions, the interrupt
920  * remains enabled.
921  *
922  * Return: 0 on success. On failure, -EWOULDBLOCK if there's still outstanding
923  * transaction(s).
924  */
925 static int xilinx_dpdma_chan_notify_no_ostand(struct xilinx_dpdma_chan *chan)
926 {
927 	u32 cnt;
928 
929 	cnt = xilinx_dpdma_chan_ostand(chan);
930 	if (cnt) {
931 		dev_dbg(chan->xdev->dev, "%d outstanding transactions\n", cnt);
932 		return -EWOULDBLOCK;
933 	}
934 
935 	/* Disable 'no outstanding' interrupt */
936 	dpdma_write(chan->xdev->reg, XILINX_DPDMA_IDS,
937 		    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
938 	wake_up(&chan->wait_to_stop);
939 
940 	return 0;
941 }
942 
943 /**
944  * xilinx_dpdma_chan_wait_no_ostand - Wait for the no outstanding irq
945  * @chan: DPDMA channel
946  *
947  * Wait for the no outstanding transaction interrupt. This functions can sleep
948  * for 50ms.
949  *
950  * Return: 0 on success. On failure, -ETIMEOUT for time out, or the error code
951  * from wait_event_interruptible_timeout().
952  */
953 static int xilinx_dpdma_chan_wait_no_ostand(struct xilinx_dpdma_chan *chan)
954 {
955 	int ret;
956 
957 	/* Wait for a no outstanding transaction interrupt upto 50msec */
958 	ret = wait_event_interruptible_timeout(chan->wait_to_stop,
959 					       !xilinx_dpdma_chan_ostand(chan),
960 					       msecs_to_jiffies(50));
961 	if (ret > 0) {
962 		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
963 			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
964 		return 0;
965 	}
966 
967 	dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
968 		xilinx_dpdma_chan_ostand(chan));
969 
970 	if (ret == 0)
971 		return -ETIMEDOUT;
972 
973 	return ret;
974 }
975 
976 /**
977  * xilinx_dpdma_chan_poll_no_ostand - Poll the outstanding transaction status
978  * @chan: DPDMA channel
979  *
980  * Poll the outstanding transaction status, and return when there's no
981  * outstanding transaction. This functions can be used in the interrupt context
982  * or where the atomicity is required. Calling thread may wait more than 50ms.
983  *
984  * Return: 0 on success, or -ETIMEDOUT.
985  */
986 static int xilinx_dpdma_chan_poll_no_ostand(struct xilinx_dpdma_chan *chan)
987 {
988 	u32 cnt, loop = 50000;
989 
990 	/* Poll at least for 50ms (20 fps). */
991 	do {
992 		cnt = xilinx_dpdma_chan_ostand(chan);
993 		udelay(1);
994 	} while (loop-- > 0 && cnt);
995 
996 	if (loop) {
997 		dpdma_write(chan->xdev->reg, XILINX_DPDMA_IEN,
998 			    XILINX_DPDMA_INTR_NO_OSTAND(chan->id));
999 		return 0;
1000 	}
1001 
1002 	dev_err(chan->xdev->dev, "not ready to stop: %d trans\n",
1003 		xilinx_dpdma_chan_ostand(chan));
1004 
1005 	return -ETIMEDOUT;
1006 }
1007 
1008 /**
1009  * xilinx_dpdma_chan_stop - Stop the channel
1010  * @chan: DPDMA channel
1011  *
1012  * Stop a previously paused channel by first waiting for completion of all
1013  * outstanding transaction and then disabling the channel.
1014  *
1015  * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
1016  */
1017 static int xilinx_dpdma_chan_stop(struct xilinx_dpdma_chan *chan)
1018 {
1019 	unsigned long flags;
1020 	int ret;
1021 
1022 	ret = xilinx_dpdma_chan_wait_no_ostand(chan);
1023 	if (ret)
1024 		return ret;
1025 
1026 	spin_lock_irqsave(&chan->lock, flags);
1027 	xilinx_dpdma_chan_disable(chan);
1028 	chan->running = false;
1029 	spin_unlock_irqrestore(&chan->lock, flags);
1030 
1031 	return 0;
1032 }
1033 
1034 /**
1035  * xilinx_dpdma_chan_done_irq - Handle hardware descriptor completion
1036  * @chan: DPDMA channel
1037  *
1038  * Handle completion of the currently active descriptor (@chan->desc.active). As
1039  * we currently support cyclic transfers only, this just invokes the cyclic
1040  * callback. The descriptor will be completed at the VSYNC interrupt when a new
1041  * descriptor replaces it.
1042  */
1043 static void xilinx_dpdma_chan_done_irq(struct xilinx_dpdma_chan *chan)
1044 {
1045 	struct xilinx_dpdma_tx_desc *active = chan->desc.active;
1046 	unsigned long flags;
1047 
1048 	spin_lock_irqsave(&chan->lock, flags);
1049 
1050 	xilinx_dpdma_debugfs_desc_done_irq(chan);
1051 
1052 	if (active)
1053 		vchan_cyclic_callback(&active->vdesc);
1054 	else
1055 		dev_warn(chan->xdev->dev,
1056 			 "DONE IRQ with no active descriptor!\n");
1057 
1058 	spin_unlock_irqrestore(&chan->lock, flags);
1059 }
1060 
1061 /**
1062  * xilinx_dpdma_chan_vsync_irq - Handle hardware descriptor scheduling
1063  * @chan: DPDMA channel
1064  *
1065  * At VSYNC the active descriptor may have been replaced by the pending
1066  * descriptor. Detect this through the DESC_ID and perform appropriate
1067  * bookkeeping.
1068  */
1069 static void xilinx_dpdma_chan_vsync_irq(struct  xilinx_dpdma_chan *chan)
1070 {
1071 	struct xilinx_dpdma_tx_desc *pending;
1072 	struct xilinx_dpdma_sw_desc *sw_desc;
1073 	unsigned long flags;
1074 	u32 desc_id;
1075 
1076 	spin_lock_irqsave(&chan->lock, flags);
1077 
1078 	pending = chan->desc.pending;
1079 	if (!chan->running || !pending)
1080 		goto out;
1081 
1082 	desc_id = dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_ID);
1083 
1084 	/* If the retrigger raced with vsync, retry at the next frame. */
1085 	sw_desc = list_first_entry(&pending->descriptors,
1086 				   struct xilinx_dpdma_sw_desc, node);
1087 	if (sw_desc->hw.desc_id != desc_id)
1088 		goto out;
1089 
1090 	/*
1091 	 * Complete the active descriptor, if any, promote the pending
1092 	 * descriptor to active, and queue the next transfer, if any.
1093 	 */
1094 	if (chan->desc.active)
1095 		vchan_cookie_complete(&chan->desc.active->vdesc);
1096 	chan->desc.active = pending;
1097 	chan->desc.pending = NULL;
1098 
1099 	xilinx_dpdma_chan_queue_transfer(chan);
1100 
1101 out:
1102 	spin_unlock_irqrestore(&chan->lock, flags);
1103 }
1104 
1105 /**
1106  * xilinx_dpdma_chan_err - Detect any channel error
1107  * @chan: DPDMA channel
1108  * @isr: masked Interrupt Status Register
1109  * @eisr: Error Interrupt Status Register
1110  *
1111  * Return: true if any channel error occurs, or false otherwise.
1112  */
1113 static bool
1114 xilinx_dpdma_chan_err(struct xilinx_dpdma_chan *chan, u32 isr, u32 eisr)
1115 {
1116 	if (!chan)
1117 		return false;
1118 
1119 	if (chan->running &&
1120 	    ((isr & (XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id)) ||
1121 	    (eisr & (XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id))))
1122 		return true;
1123 
1124 	return false;
1125 }
1126 
1127 /**
1128  * xilinx_dpdma_chan_handle_err - DPDMA channel error handling
1129  * @chan: DPDMA channel
1130  *
1131  * This function is called when any channel error or any global error occurs.
1132  * The function disables the paused channel by errors and determines
1133  * if the current active descriptor can be rescheduled depending on
1134  * the descriptor status.
1135  */
1136 static void xilinx_dpdma_chan_handle_err(struct xilinx_dpdma_chan *chan)
1137 {
1138 	struct xilinx_dpdma_device *xdev = chan->xdev;
1139 	struct xilinx_dpdma_tx_desc *active;
1140 	unsigned long flags;
1141 
1142 	spin_lock_irqsave(&chan->lock, flags);
1143 
1144 	dev_dbg(xdev->dev, "cur desc addr = 0x%04x%08x\n",
1145 		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDRE),
1146 		dpdma_read(chan->reg, XILINX_DPDMA_CH_DESC_START_ADDR));
1147 	dev_dbg(xdev->dev, "cur payload addr = 0x%04x%08x\n",
1148 		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDRE),
1149 		dpdma_read(chan->reg, XILINX_DPDMA_CH_PYLD_CUR_ADDR));
1150 
1151 	xilinx_dpdma_chan_disable(chan);
1152 	chan->running = false;
1153 
1154 	if (!chan->desc.active)
1155 		goto out_unlock;
1156 
1157 	active = chan->desc.active;
1158 	chan->desc.active = NULL;
1159 
1160 	xilinx_dpdma_chan_dump_tx_desc(chan, active);
1161 
1162 	if (active->error)
1163 		dev_dbg(xdev->dev, "repeated error on desc\n");
1164 
1165 	/* Reschedule if there's no new descriptor */
1166 	if (!chan->desc.pending &&
1167 	    list_empty(&chan->vchan.desc_issued)) {
1168 		active->error = true;
1169 		list_add_tail(&active->vdesc.node,
1170 			      &chan->vchan.desc_issued);
1171 	} else {
1172 		xilinx_dpdma_chan_free_tx_desc(&active->vdesc);
1173 	}
1174 
1175 out_unlock:
1176 	spin_unlock_irqrestore(&chan->lock, flags);
1177 }
1178 
1179 /* -----------------------------------------------------------------------------
1180  * DMA Engine Operations
1181  */
1182 
1183 static struct dma_async_tx_descriptor *
1184 xilinx_dpdma_prep_interleaved_dma(struct dma_chan *dchan,
1185 				  struct dma_interleaved_template *xt,
1186 				  unsigned long flags)
1187 {
1188 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1189 	struct xilinx_dpdma_tx_desc *desc;
1190 
1191 	if (xt->dir != DMA_MEM_TO_DEV)
1192 		return NULL;
1193 
1194 	if (!xt->numf || !xt->sgl[0].size)
1195 		return NULL;
1196 
1197 	if (!(flags & DMA_PREP_REPEAT) || !(flags & DMA_PREP_LOAD_EOT))
1198 		return NULL;
1199 
1200 	desc = xilinx_dpdma_chan_prep_interleaved_dma(chan, xt);
1201 	if (!desc)
1202 		return NULL;
1203 
1204 	vchan_tx_prep(&chan->vchan, &desc->vdesc, flags | DMA_CTRL_ACK);
1205 
1206 	return &desc->vdesc.tx;
1207 }
1208 
1209 /**
1210  * xilinx_dpdma_alloc_chan_resources - Allocate resources for the channel
1211  * @dchan: DMA channel
1212  *
1213  * Allocate a descriptor pool for the channel.
1214  *
1215  * Return: 0 on success, or -ENOMEM if failed to allocate a pool.
1216  */
1217 static int xilinx_dpdma_alloc_chan_resources(struct dma_chan *dchan)
1218 {
1219 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1220 	size_t align = __alignof__(struct xilinx_dpdma_sw_desc);
1221 
1222 	chan->desc_pool = dma_pool_create(dev_name(chan->xdev->dev),
1223 					  chan->xdev->dev,
1224 					  sizeof(struct xilinx_dpdma_sw_desc),
1225 					  align, 0);
1226 	if (!chan->desc_pool) {
1227 		dev_err(chan->xdev->dev,
1228 			"failed to allocate a descriptor pool\n");
1229 		return -ENOMEM;
1230 	}
1231 
1232 	return 0;
1233 }
1234 
1235 /**
1236  * xilinx_dpdma_free_chan_resources - Free all resources for the channel
1237  * @dchan: DMA channel
1238  *
1239  * Free resources associated with the virtual DMA channel, and destroy the
1240  * descriptor pool.
1241  */
1242 static void xilinx_dpdma_free_chan_resources(struct dma_chan *dchan)
1243 {
1244 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1245 
1246 	vchan_free_chan_resources(&chan->vchan);
1247 
1248 	dma_pool_destroy(chan->desc_pool);
1249 	chan->desc_pool = NULL;
1250 }
1251 
1252 static void xilinx_dpdma_issue_pending(struct dma_chan *dchan)
1253 {
1254 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1255 	unsigned long flags;
1256 
1257 	spin_lock_irqsave(&chan->vchan.lock, flags);
1258 	if (vchan_issue_pending(&chan->vchan))
1259 		xilinx_dpdma_chan_queue_transfer(chan);
1260 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1261 }
1262 
1263 static int xilinx_dpdma_config(struct dma_chan *dchan,
1264 			       struct dma_slave_config *config)
1265 {
1266 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1267 	unsigned long flags;
1268 
1269 	/*
1270 	 * The destination address doesn't need to be specified as the DPDMA is
1271 	 * hardwired to the destination (the DP controller). The transfer
1272 	 * width, burst size and port window size are thus meaningless, they're
1273 	 * fixed both on the DPDMA side and on the DP controller side.
1274 	 */
1275 
1276 	spin_lock_irqsave(&chan->lock, flags);
1277 
1278 	/*
1279 	 * Abuse the slave_id to indicate that the channel is part of a video
1280 	 * group.
1281 	 */
1282 	if (chan->id <= ZYNQMP_DPDMA_VIDEO2)
1283 		chan->video_group = config->slave_id != 0;
1284 
1285 	spin_unlock_irqrestore(&chan->lock, flags);
1286 
1287 	return 0;
1288 }
1289 
1290 static int xilinx_dpdma_pause(struct dma_chan *dchan)
1291 {
1292 	xilinx_dpdma_chan_pause(to_xilinx_chan(dchan));
1293 
1294 	return 0;
1295 }
1296 
1297 static int xilinx_dpdma_resume(struct dma_chan *dchan)
1298 {
1299 	xilinx_dpdma_chan_unpause(to_xilinx_chan(dchan));
1300 
1301 	return 0;
1302 }
1303 
1304 /**
1305  * xilinx_dpdma_terminate_all - Terminate the channel and descriptors
1306  * @dchan: DMA channel
1307  *
1308  * Pause the channel without waiting for ongoing transfers to complete. Waiting
1309  * for completion is performed by xilinx_dpdma_synchronize() that will disable
1310  * the channel to complete the stop.
1311  *
1312  * All the descriptors associated with the channel that are guaranteed not to
1313  * be touched by the hardware. The pending and active descriptor are not
1314  * touched, and will be freed either upon completion, or by
1315  * xilinx_dpdma_synchronize().
1316  *
1317  * Return: 0 on success, or -ETIMEDOUT if the channel failed to stop.
1318  */
1319 static int xilinx_dpdma_terminate_all(struct dma_chan *dchan)
1320 {
1321 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1322 	struct xilinx_dpdma_device *xdev = chan->xdev;
1323 	LIST_HEAD(descriptors);
1324 	unsigned long flags;
1325 	unsigned int i;
1326 
1327 	/* Pause the channel (including the whole video group if applicable). */
1328 	if (chan->video_group) {
1329 		for (i = ZYNQMP_DPDMA_VIDEO0; i <= ZYNQMP_DPDMA_VIDEO2; i++) {
1330 			if (xdev->chan[i]->video_group &&
1331 			    xdev->chan[i]->running) {
1332 				xilinx_dpdma_chan_pause(xdev->chan[i]);
1333 				xdev->chan[i]->video_group = false;
1334 			}
1335 		}
1336 	} else {
1337 		xilinx_dpdma_chan_pause(chan);
1338 	}
1339 
1340 	/* Gather all the descriptors we can free and free them. */
1341 	spin_lock_irqsave(&chan->vchan.lock, flags);
1342 	vchan_get_all_descriptors(&chan->vchan, &descriptors);
1343 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1344 
1345 	vchan_dma_desc_free_list(&chan->vchan, &descriptors);
1346 
1347 	return 0;
1348 }
1349 
1350 /**
1351  * xilinx_dpdma_synchronize - Synchronize callback execution
1352  * @dchan: DMA channel
1353  *
1354  * Synchronizing callback execution ensures that all previously issued
1355  * transfers have completed and all associated callbacks have been called and
1356  * have returned.
1357  *
1358  * This function waits for the DMA channel to stop. It assumes it has been
1359  * paused by a previous call to dmaengine_terminate_async(), and that no new
1360  * pending descriptors have been issued with dma_async_issue_pending(). The
1361  * behaviour is undefined otherwise.
1362  */
1363 static void xilinx_dpdma_synchronize(struct dma_chan *dchan)
1364 {
1365 	struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan);
1366 	unsigned long flags;
1367 
1368 	xilinx_dpdma_chan_stop(chan);
1369 
1370 	spin_lock_irqsave(&chan->vchan.lock, flags);
1371 	if (chan->desc.pending) {
1372 		vchan_terminate_vdesc(&chan->desc.pending->vdesc);
1373 		chan->desc.pending = NULL;
1374 	}
1375 	if (chan->desc.active) {
1376 		vchan_terminate_vdesc(&chan->desc.active->vdesc);
1377 		chan->desc.active = NULL;
1378 	}
1379 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1380 
1381 	vchan_synchronize(&chan->vchan);
1382 }
1383 
1384 /* -----------------------------------------------------------------------------
1385  * Interrupt and Tasklet Handling
1386  */
1387 
1388 /**
1389  * xilinx_dpdma_err - Detect any global error
1390  * @isr: Interrupt Status Register
1391  * @eisr: Error Interrupt Status Register
1392  *
1393  * Return: True if any global error occurs, or false otherwise.
1394  */
1395 static bool xilinx_dpdma_err(u32 isr, u32 eisr)
1396 {
1397 	if (isr & XILINX_DPDMA_INTR_GLOBAL_ERR ||
1398 	    eisr & XILINX_DPDMA_EINTR_GLOBAL_ERR)
1399 		return true;
1400 
1401 	return false;
1402 }
1403 
1404 /**
1405  * xilinx_dpdma_handle_err_irq - Handle DPDMA error interrupt
1406  * @xdev: DPDMA device
1407  * @isr: masked Interrupt Status Register
1408  * @eisr: Error Interrupt Status Register
1409  *
1410  * Handle if any error occurs based on @isr and @eisr. This function disables
1411  * corresponding error interrupts, and those should be re-enabled once handling
1412  * is done.
1413  */
1414 static void xilinx_dpdma_handle_err_irq(struct xilinx_dpdma_device *xdev,
1415 					u32 isr, u32 eisr)
1416 {
1417 	bool err = xilinx_dpdma_err(isr, eisr);
1418 	unsigned int i;
1419 
1420 	dev_dbg_ratelimited(xdev->dev,
1421 			    "error irq: isr = 0x%08x, eisr = 0x%08x\n",
1422 			    isr, eisr);
1423 
1424 	/* Disable channel error interrupts until errors are handled. */
1425 	dpdma_write(xdev->reg, XILINX_DPDMA_IDS,
1426 		    isr & ~XILINX_DPDMA_INTR_GLOBAL_ERR);
1427 	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS,
1428 		    eisr & ~XILINX_DPDMA_EINTR_GLOBAL_ERR);
1429 
1430 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1431 		if (err || xilinx_dpdma_chan_err(xdev->chan[i], isr, eisr))
1432 			tasklet_schedule(&xdev->chan[i]->err_task);
1433 }
1434 
1435 /**
1436  * xilinx_dpdma_enable_irq - Enable interrupts
1437  * @xdev: DPDMA device
1438  *
1439  * Enable interrupts.
1440  */
1441 static void xilinx_dpdma_enable_irq(struct xilinx_dpdma_device *xdev)
1442 {
1443 	dpdma_write(xdev->reg, XILINX_DPDMA_IEN, XILINX_DPDMA_INTR_ALL);
1444 	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN, XILINX_DPDMA_EINTR_ALL);
1445 }
1446 
1447 /**
1448  * xilinx_dpdma_disable_irq - Disable interrupts
1449  * @xdev: DPDMA device
1450  *
1451  * Disable interrupts.
1452  */
1453 static void xilinx_dpdma_disable_irq(struct xilinx_dpdma_device *xdev)
1454 {
1455 	dpdma_write(xdev->reg, XILINX_DPDMA_IDS, XILINX_DPDMA_INTR_ERR_ALL);
1456 	dpdma_write(xdev->reg, XILINX_DPDMA_EIDS, XILINX_DPDMA_EINTR_ALL);
1457 }
1458 
1459 /**
1460  * xilinx_dpdma_chan_err_task - Per channel tasklet for error handling
1461  * @data: tasklet data to be casted to DPDMA channel structure
1462  *
1463  * Per channel error handling tasklet. This function waits for the outstanding
1464  * transaction to complete and triggers error handling. After error handling,
1465  * re-enable channel error interrupts, and restart the channel if needed.
1466  */
1467 static void xilinx_dpdma_chan_err_task(unsigned long data)
1468 {
1469 	struct xilinx_dpdma_chan *chan = (struct xilinx_dpdma_chan *)data;
1470 	struct xilinx_dpdma_device *xdev = chan->xdev;
1471 	unsigned long flags;
1472 
1473 	/* Proceed error handling even when polling fails. */
1474 	xilinx_dpdma_chan_poll_no_ostand(chan);
1475 
1476 	xilinx_dpdma_chan_handle_err(chan);
1477 
1478 	dpdma_write(xdev->reg, XILINX_DPDMA_IEN,
1479 		    XILINX_DPDMA_INTR_CHAN_ERR_MASK << chan->id);
1480 	dpdma_write(xdev->reg, XILINX_DPDMA_EIEN,
1481 		    XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id);
1482 
1483 	spin_lock_irqsave(&chan->lock, flags);
1484 	xilinx_dpdma_chan_queue_transfer(chan);
1485 	spin_unlock_irqrestore(&chan->lock, flags);
1486 }
1487 
1488 static irqreturn_t xilinx_dpdma_irq_handler(int irq, void *data)
1489 {
1490 	struct xilinx_dpdma_device *xdev = data;
1491 	unsigned long mask;
1492 	unsigned int i;
1493 	u32 status;
1494 	u32 error;
1495 
1496 	status = dpdma_read(xdev->reg, XILINX_DPDMA_ISR);
1497 	error = dpdma_read(xdev->reg, XILINX_DPDMA_EISR);
1498 	if (!status && !error)
1499 		return IRQ_NONE;
1500 
1501 	dpdma_write(xdev->reg, XILINX_DPDMA_ISR, status);
1502 	dpdma_write(xdev->reg, XILINX_DPDMA_EISR, error);
1503 
1504 	if (status & XILINX_DPDMA_INTR_VSYNC) {
1505 		/*
1506 		 * There's a single VSYNC interrupt that needs to be processed
1507 		 * by each running channel to update the active descriptor.
1508 		 */
1509 		for (i = 0; i < ARRAY_SIZE(xdev->chan); i++) {
1510 			struct xilinx_dpdma_chan *chan = xdev->chan[i];
1511 
1512 			if (chan)
1513 				xilinx_dpdma_chan_vsync_irq(chan);
1514 		}
1515 	}
1516 
1517 	mask = FIELD_GET(XILINX_DPDMA_INTR_DESC_DONE_MASK, status);
1518 	if (mask) {
1519 		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
1520 			xilinx_dpdma_chan_done_irq(xdev->chan[i]);
1521 	}
1522 
1523 	mask = FIELD_GET(XILINX_DPDMA_INTR_NO_OSTAND_MASK, status);
1524 	if (mask) {
1525 		for_each_set_bit(i, &mask, ARRAY_SIZE(xdev->chan))
1526 			xilinx_dpdma_chan_notify_no_ostand(xdev->chan[i]);
1527 	}
1528 
1529 	mask = status & XILINX_DPDMA_INTR_ERR_ALL;
1530 	if (mask || error)
1531 		xilinx_dpdma_handle_err_irq(xdev, mask, error);
1532 
1533 	return IRQ_HANDLED;
1534 }
1535 
1536 /* -----------------------------------------------------------------------------
1537  * Initialization & Cleanup
1538  */
1539 
1540 static int xilinx_dpdma_chan_init(struct xilinx_dpdma_device *xdev,
1541 				  unsigned int chan_id)
1542 {
1543 	struct xilinx_dpdma_chan *chan;
1544 
1545 	chan = devm_kzalloc(xdev->dev, sizeof(*chan), GFP_KERNEL);
1546 	if (!chan)
1547 		return -ENOMEM;
1548 
1549 	chan->id = chan_id;
1550 	chan->reg = xdev->reg + XILINX_DPDMA_CH_BASE
1551 		  + XILINX_DPDMA_CH_OFFSET * chan->id;
1552 	chan->running = false;
1553 	chan->xdev = xdev;
1554 
1555 	spin_lock_init(&chan->lock);
1556 	init_waitqueue_head(&chan->wait_to_stop);
1557 
1558 	tasklet_init(&chan->err_task, xilinx_dpdma_chan_err_task,
1559 		     (unsigned long)chan);
1560 
1561 	chan->vchan.desc_free = xilinx_dpdma_chan_free_tx_desc;
1562 	vchan_init(&chan->vchan, &xdev->common);
1563 
1564 	xdev->chan[chan->id] = chan;
1565 
1566 	return 0;
1567 }
1568 
1569 static void xilinx_dpdma_chan_remove(struct xilinx_dpdma_chan *chan)
1570 {
1571 	if (!chan)
1572 		return;
1573 
1574 	tasklet_kill(&chan->err_task);
1575 	list_del(&chan->vchan.chan.device_node);
1576 }
1577 
1578 static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,
1579 					    struct of_dma *ofdma)
1580 {
1581 	struct xilinx_dpdma_device *xdev = ofdma->of_dma_data;
1582 	uint32_t chan_id = dma_spec->args[0];
1583 
1584 	if (chan_id >= ARRAY_SIZE(xdev->chan))
1585 		return NULL;
1586 
1587 	if (!xdev->chan[chan_id])
1588 		return NULL;
1589 
1590 	return dma_get_slave_channel(&xdev->chan[chan_id]->vchan.chan);
1591 }
1592 
1593 static int xilinx_dpdma_probe(struct platform_device *pdev)
1594 {
1595 	struct xilinx_dpdma_device *xdev;
1596 	struct dma_device *ddev;
1597 	unsigned int i;
1598 	int ret;
1599 
1600 	xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
1601 	if (!xdev)
1602 		return -ENOMEM;
1603 
1604 	xdev->dev = &pdev->dev;
1605 	xdev->ext_addr = sizeof(dma_addr_t) > 4;
1606 
1607 	INIT_LIST_HEAD(&xdev->common.channels);
1608 
1609 	platform_set_drvdata(pdev, xdev);
1610 
1611 	xdev->axi_clk = devm_clk_get(xdev->dev, "axi_clk");
1612 	if (IS_ERR(xdev->axi_clk))
1613 		return PTR_ERR(xdev->axi_clk);
1614 
1615 	xdev->reg = devm_platform_ioremap_resource(pdev, 0);
1616 	if (IS_ERR(xdev->reg))
1617 		return PTR_ERR(xdev->reg);
1618 
1619 	xdev->irq = platform_get_irq(pdev, 0);
1620 	if (xdev->irq < 0) {
1621 		dev_err(xdev->dev, "failed to get platform irq\n");
1622 		return xdev->irq;
1623 	}
1624 
1625 	ret = request_irq(xdev->irq, xilinx_dpdma_irq_handler, IRQF_SHARED,
1626 			  dev_name(xdev->dev), xdev);
1627 	if (ret) {
1628 		dev_err(xdev->dev, "failed to request IRQ\n");
1629 		return ret;
1630 	}
1631 
1632 	ddev = &xdev->common;
1633 	ddev->dev = &pdev->dev;
1634 
1635 	dma_cap_set(DMA_SLAVE, ddev->cap_mask);
1636 	dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
1637 	dma_cap_set(DMA_INTERLEAVE, ddev->cap_mask);
1638 	dma_cap_set(DMA_REPEAT, ddev->cap_mask);
1639 	dma_cap_set(DMA_LOAD_EOT, ddev->cap_mask);
1640 	ddev->copy_align = fls(XILINX_DPDMA_ALIGN_BYTES - 1);
1641 
1642 	ddev->device_alloc_chan_resources = xilinx_dpdma_alloc_chan_resources;
1643 	ddev->device_free_chan_resources = xilinx_dpdma_free_chan_resources;
1644 	ddev->device_prep_interleaved_dma = xilinx_dpdma_prep_interleaved_dma;
1645 	/* TODO: Can we achieve better granularity ? */
1646 	ddev->device_tx_status = dma_cookie_status;
1647 	ddev->device_issue_pending = xilinx_dpdma_issue_pending;
1648 	ddev->device_config = xilinx_dpdma_config;
1649 	ddev->device_pause = xilinx_dpdma_pause;
1650 	ddev->device_resume = xilinx_dpdma_resume;
1651 	ddev->device_terminate_all = xilinx_dpdma_terminate_all;
1652 	ddev->device_synchronize = xilinx_dpdma_synchronize;
1653 	ddev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED);
1654 	ddev->directions = BIT(DMA_MEM_TO_DEV);
1655 	ddev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1656 
1657 	for (i = 0; i < ARRAY_SIZE(xdev->chan); ++i) {
1658 		ret = xilinx_dpdma_chan_init(xdev, i);
1659 		if (ret < 0) {
1660 			dev_err(xdev->dev, "failed to initialize channel %u\n",
1661 				i);
1662 			goto error;
1663 		}
1664 	}
1665 
1666 	ret = clk_prepare_enable(xdev->axi_clk);
1667 	if (ret) {
1668 		dev_err(xdev->dev, "failed to enable the axi clock\n");
1669 		goto error;
1670 	}
1671 
1672 	ret = dma_async_device_register(ddev);
1673 	if (ret) {
1674 		dev_err(xdev->dev, "failed to register the dma device\n");
1675 		goto error_dma_async;
1676 	}
1677 
1678 	ret = of_dma_controller_register(xdev->dev->of_node,
1679 					 of_dma_xilinx_xlate, ddev);
1680 	if (ret) {
1681 		dev_err(xdev->dev, "failed to register DMA to DT DMA helper\n");
1682 		goto error_of_dma;
1683 	}
1684 
1685 	xilinx_dpdma_enable_irq(xdev);
1686 
1687 	xilinx_dpdma_debugfs_init(xdev);
1688 
1689 	dev_info(&pdev->dev, "Xilinx DPDMA engine is probed\n");
1690 
1691 	return 0;
1692 
1693 error_of_dma:
1694 	dma_async_device_unregister(ddev);
1695 error_dma_async:
1696 	clk_disable_unprepare(xdev->axi_clk);
1697 error:
1698 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1699 		xilinx_dpdma_chan_remove(xdev->chan[i]);
1700 
1701 	free_irq(xdev->irq, xdev);
1702 
1703 	return ret;
1704 }
1705 
1706 static int xilinx_dpdma_remove(struct platform_device *pdev)
1707 {
1708 	struct xilinx_dpdma_device *xdev = platform_get_drvdata(pdev);
1709 	unsigned int i;
1710 
1711 	/* Start by disabling the IRQ to avoid races during cleanup. */
1712 	free_irq(xdev->irq, xdev);
1713 
1714 	xilinx_dpdma_disable_irq(xdev);
1715 	of_dma_controller_free(pdev->dev.of_node);
1716 	dma_async_device_unregister(&xdev->common);
1717 	clk_disable_unprepare(xdev->axi_clk);
1718 
1719 	for (i = 0; i < ARRAY_SIZE(xdev->chan); i++)
1720 		xilinx_dpdma_chan_remove(xdev->chan[i]);
1721 
1722 	return 0;
1723 }
1724 
1725 static const struct of_device_id xilinx_dpdma_of_match[] = {
1726 	{ .compatible = "xlnx,zynqmp-dpdma",},
1727 	{ /* end of table */ },
1728 };
1729 MODULE_DEVICE_TABLE(of, xilinx_dpdma_of_match);
1730 
1731 static struct platform_driver xilinx_dpdma_driver = {
1732 	.probe			= xilinx_dpdma_probe,
1733 	.remove			= xilinx_dpdma_remove,
1734 	.driver			= {
1735 		.name		= "xilinx-zynqmp-dpdma",
1736 		.of_match_table	= xilinx_dpdma_of_match,
1737 	},
1738 };
1739 
1740 module_platform_driver(xilinx_dpdma_driver);
1741 
1742 MODULE_AUTHOR("Xilinx, Inc.");
1743 MODULE_DESCRIPTION("Xilinx ZynqMP DPDMA driver");
1744 MODULE_LICENSE("GPL v2");
1745