xref: /openbmc/linux/drivers/dma/stm32-mdma.c (revision fe4549b1)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright (C) STMicroelectronics SA 2017
5  * Author(s): M'boumba Cedric Madianga <cedric.madianga@gmail.com>
6  *            Pierre-Yves Mordret <pierre-yves.mordret@st.com>
7  *
8  * Driver for STM32 MDMA controller
9  *
10  * Inspired by stm32-dma.c and dma-jz4780.c
11  */
12 
13 #include <linux/bitfield.h>
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/dmaengine.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/dmapool.h>
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/iopoll.h>
22 #include <linux/jiffies.h>
23 #include <linux/list.h>
24 #include <linux/log2.h>
25 #include <linux/module.h>
26 #include <linux/of.h>
27 #include <linux/of_dma.h>
28 #include <linux/platform_device.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/reset.h>
31 #include <linux/slab.h>
32 
33 #include "virt-dma.h"
34 
35 #define STM32_MDMA_GISR0		0x0000 /* MDMA Int Status Reg 1 */
36 
37 /* MDMA Channel x interrupt/status register */
38 #define STM32_MDMA_CISR(x)		(0x40 + 0x40 * (x)) /* x = 0..62 */
39 #define STM32_MDMA_CISR_CRQA		BIT(16)
40 #define STM32_MDMA_CISR_TCIF		BIT(4)
41 #define STM32_MDMA_CISR_BTIF		BIT(3)
42 #define STM32_MDMA_CISR_BRTIF		BIT(2)
43 #define STM32_MDMA_CISR_CTCIF		BIT(1)
44 #define STM32_MDMA_CISR_TEIF		BIT(0)
45 
46 /* MDMA Channel x interrupt flag clear register */
47 #define STM32_MDMA_CIFCR(x)		(0x44 + 0x40 * (x))
48 #define STM32_MDMA_CIFCR_CLTCIF		BIT(4)
49 #define STM32_MDMA_CIFCR_CBTIF		BIT(3)
50 #define STM32_MDMA_CIFCR_CBRTIF		BIT(2)
51 #define STM32_MDMA_CIFCR_CCTCIF		BIT(1)
52 #define STM32_MDMA_CIFCR_CTEIF		BIT(0)
53 #define STM32_MDMA_CIFCR_CLEAR_ALL	(STM32_MDMA_CIFCR_CLTCIF \
54 					| STM32_MDMA_CIFCR_CBTIF \
55 					| STM32_MDMA_CIFCR_CBRTIF \
56 					| STM32_MDMA_CIFCR_CCTCIF \
57 					| STM32_MDMA_CIFCR_CTEIF)
58 
59 /* MDMA Channel x error status register */
60 #define STM32_MDMA_CESR(x)		(0x48 + 0x40 * (x))
61 #define STM32_MDMA_CESR_BSE		BIT(11)
62 #define STM32_MDMA_CESR_ASR		BIT(10)
63 #define STM32_MDMA_CESR_TEMD		BIT(9)
64 #define STM32_MDMA_CESR_TELD		BIT(8)
65 #define STM32_MDMA_CESR_TED		BIT(7)
66 #define STM32_MDMA_CESR_TEA_MASK	GENMASK(6, 0)
67 
68 /* MDMA Channel x control register */
69 #define STM32_MDMA_CCR(x)		(0x4C + 0x40 * (x))
70 #define STM32_MDMA_CCR_SWRQ		BIT(16)
71 #define STM32_MDMA_CCR_WEX		BIT(14)
72 #define STM32_MDMA_CCR_HEX		BIT(13)
73 #define STM32_MDMA_CCR_BEX		BIT(12)
74 #define STM32_MDMA_CCR_SM		BIT(8)
75 #define STM32_MDMA_CCR_PL_MASK		GENMASK(7, 6)
76 #define STM32_MDMA_CCR_PL(n)		FIELD_PREP(STM32_MDMA_CCR_PL_MASK, (n))
77 #define STM32_MDMA_CCR_TCIE		BIT(5)
78 #define STM32_MDMA_CCR_BTIE		BIT(4)
79 #define STM32_MDMA_CCR_BRTIE		BIT(3)
80 #define STM32_MDMA_CCR_CTCIE		BIT(2)
81 #define STM32_MDMA_CCR_TEIE		BIT(1)
82 #define STM32_MDMA_CCR_EN		BIT(0)
83 #define STM32_MDMA_CCR_IRQ_MASK		(STM32_MDMA_CCR_TCIE \
84 					| STM32_MDMA_CCR_BTIE \
85 					| STM32_MDMA_CCR_BRTIE \
86 					| STM32_MDMA_CCR_CTCIE \
87 					| STM32_MDMA_CCR_TEIE)
88 
89 /* MDMA Channel x transfer configuration register */
90 #define STM32_MDMA_CTCR(x)		(0x50 + 0x40 * (x))
91 #define STM32_MDMA_CTCR_BWM		BIT(31)
92 #define STM32_MDMA_CTCR_SWRM		BIT(30)
93 #define STM32_MDMA_CTCR_TRGM_MSK	GENMASK(29, 28)
94 #define STM32_MDMA_CTCR_TRGM(n)		FIELD_PREP(STM32_MDMA_CTCR_TRGM_MSK, (n))
95 #define STM32_MDMA_CTCR_TRGM_GET(n)	FIELD_GET(STM32_MDMA_CTCR_TRGM_MSK, (n))
96 #define STM32_MDMA_CTCR_PAM_MASK	GENMASK(27, 26)
97 #define STM32_MDMA_CTCR_PAM(n)		FIELD_PREP(STM32_MDMA_CTCR_PAM_MASK, (n))
98 #define STM32_MDMA_CTCR_PKE		BIT(25)
99 #define STM32_MDMA_CTCR_TLEN_MSK	GENMASK(24, 18)
100 #define STM32_MDMA_CTCR_TLEN(n)		FIELD_PREP(STM32_MDMA_CTCR_TLEN_MSK, (n))
101 #define STM32_MDMA_CTCR_TLEN_GET(n)	FIELD_GET(STM32_MDMA_CTCR_TLEN_MSK, (n))
102 #define STM32_MDMA_CTCR_LEN2_MSK	GENMASK(25, 18)
103 #define STM32_MDMA_CTCR_LEN2(n)		FIELD_PREP(STM32_MDMA_CTCR_LEN2_MSK, (n))
104 #define STM32_MDMA_CTCR_LEN2_GET(n)	FIELD_GET(STM32_MDMA_CTCR_LEN2_MSK, (n))
105 #define STM32_MDMA_CTCR_DBURST_MASK	GENMASK(17, 15)
106 #define STM32_MDMA_CTCR_DBURST(n)	FIELD_PREP(STM32_MDMA_CTCR_DBURST_MASK, (n))
107 #define STM32_MDMA_CTCR_SBURST_MASK	GENMASK(14, 12)
108 #define STM32_MDMA_CTCR_SBURST(n)	FIELD_PREP(STM32_MDMA_CTCR_SBURST_MASK, (n))
109 #define STM32_MDMA_CTCR_DINCOS_MASK	GENMASK(11, 10)
110 #define STM32_MDMA_CTCR_DINCOS(n)	FIELD_PREP(STM32_MDMA_CTCR_DINCOS_MASK, (n))
111 #define STM32_MDMA_CTCR_SINCOS_MASK	GENMASK(9, 8)
112 #define STM32_MDMA_CTCR_SINCOS(n)	FIELD_PREP(STM32_MDMA_CTCR_SINCOS_MASK, (n))
113 #define STM32_MDMA_CTCR_DSIZE_MASK	GENMASK(7, 6)
114 #define STM32_MDMA_CTCR_DSIZE(n)	FIELD_PREP(STM32_MDMA_CTCR_DSIZE_MASK, (n))
115 #define STM32_MDMA_CTCR_SSIZE_MASK	GENMASK(5, 4)
116 #define STM32_MDMA_CTCR_SSIZE(n)	FIELD_PREP(STM32_MDMA_CTCR_SSIZE_MASK, (n))
117 #define STM32_MDMA_CTCR_DINC_MASK	GENMASK(3, 2)
118 #define STM32_MDMA_CTCR_DINC(n)		FIELD_PREP(STM32_MDMA_CTCR_DINC_MASK, (n))
119 #define STM32_MDMA_CTCR_SINC_MASK	GENMASK(1, 0)
120 #define STM32_MDMA_CTCR_SINC(n)		FIELD_PREP(STM32_MDMA_CTCR_SINC_MASK, (n))
121 #define STM32_MDMA_CTCR_CFG_MASK	(STM32_MDMA_CTCR_SINC_MASK \
122 					| STM32_MDMA_CTCR_DINC_MASK \
123 					| STM32_MDMA_CTCR_SINCOS_MASK \
124 					| STM32_MDMA_CTCR_DINCOS_MASK \
125 					| STM32_MDMA_CTCR_LEN2_MSK \
126 					| STM32_MDMA_CTCR_TRGM_MSK)
127 
128 /* MDMA Channel x block number of data register */
129 #define STM32_MDMA_CBNDTR(x)		(0x54 + 0x40 * (x))
130 #define STM32_MDMA_CBNDTR_BRC_MK	GENMASK(31, 20)
131 #define STM32_MDMA_CBNDTR_BRC(n)	FIELD_PREP(STM32_MDMA_CBNDTR_BRC_MK, (n))
132 #define STM32_MDMA_CBNDTR_BRC_GET(n)	FIELD_GET(STM32_MDMA_CBNDTR_BRC_MK, (n))
133 
134 #define STM32_MDMA_CBNDTR_BRDUM		BIT(19)
135 #define STM32_MDMA_CBNDTR_BRSUM		BIT(18)
136 #define STM32_MDMA_CBNDTR_BNDT_MASK	GENMASK(16, 0)
137 #define STM32_MDMA_CBNDTR_BNDT(n)	FIELD_PREP(STM32_MDMA_CBNDTR_BNDT_MASK, (n))
138 
139 /* MDMA Channel x source address register */
140 #define STM32_MDMA_CSAR(x)		(0x58 + 0x40 * (x))
141 
142 /* MDMA Channel x destination address register */
143 #define STM32_MDMA_CDAR(x)		(0x5C + 0x40 * (x))
144 
145 /* MDMA Channel x block repeat address update register */
146 #define STM32_MDMA_CBRUR(x)		(0x60 + 0x40 * (x))
147 #define STM32_MDMA_CBRUR_DUV_MASK	GENMASK(31, 16)
148 #define STM32_MDMA_CBRUR_DUV(n)		FIELD_PREP(STM32_MDMA_CBRUR_DUV_MASK, (n))
149 #define STM32_MDMA_CBRUR_SUV_MASK	GENMASK(15, 0)
150 #define STM32_MDMA_CBRUR_SUV(n)		FIELD_PREP(STM32_MDMA_CBRUR_SUV_MASK, (n))
151 
152 /* MDMA Channel x link address register */
153 #define STM32_MDMA_CLAR(x)		(0x64 + 0x40 * (x))
154 
155 /* MDMA Channel x trigger and bus selection register */
156 #define STM32_MDMA_CTBR(x)		(0x68 + 0x40 * (x))
157 #define STM32_MDMA_CTBR_DBUS		BIT(17)
158 #define STM32_MDMA_CTBR_SBUS		BIT(16)
159 #define STM32_MDMA_CTBR_TSEL_MASK	GENMASK(5, 0)
160 #define STM32_MDMA_CTBR_TSEL(n)		FIELD_PREP(STM32_MDMA_CTBR_TSEL_MASK, (n))
161 
162 /* MDMA Channel x mask address register */
163 #define STM32_MDMA_CMAR(x)		(0x70 + 0x40 * (x))
164 
165 /* MDMA Channel x mask data register */
166 #define STM32_MDMA_CMDR(x)		(0x74 + 0x40 * (x))
167 
168 #define STM32_MDMA_MAX_BUF_LEN		128
169 #define STM32_MDMA_MAX_BLOCK_LEN	65536
170 #define STM32_MDMA_MAX_CHANNELS		32
171 #define STM32_MDMA_MAX_REQUESTS		256
172 #define STM32_MDMA_MAX_BURST		128
173 #define STM32_MDMA_VERY_HIGH_PRIORITY	0x3
174 
175 enum stm32_mdma_trigger_mode {
176 	STM32_MDMA_BUFFER,
177 	STM32_MDMA_BLOCK,
178 	STM32_MDMA_BLOCK_REP,
179 	STM32_MDMA_LINKED_LIST,
180 };
181 
182 enum stm32_mdma_width {
183 	STM32_MDMA_BYTE,
184 	STM32_MDMA_HALF_WORD,
185 	STM32_MDMA_WORD,
186 	STM32_MDMA_DOUBLE_WORD,
187 };
188 
189 enum stm32_mdma_inc_mode {
190 	STM32_MDMA_FIXED = 0,
191 	STM32_MDMA_INC = 2,
192 	STM32_MDMA_DEC = 3,
193 };
194 
195 struct stm32_mdma_chan_config {
196 	u32 request;
197 	u32 priority_level;
198 	u32 transfer_config;
199 	u32 mask_addr;
200 	u32 mask_data;
201 	bool m2m_hw; /* True when MDMA is triggered by STM32 DMA */
202 };
203 
204 struct stm32_mdma_hwdesc {
205 	u32 ctcr;
206 	u32 cbndtr;
207 	u32 csar;
208 	u32 cdar;
209 	u32 cbrur;
210 	u32 clar;
211 	u32 ctbr;
212 	u32 dummy;
213 	u32 cmar;
214 	u32 cmdr;
215 } __aligned(64);
216 
217 struct stm32_mdma_desc_node {
218 	struct stm32_mdma_hwdesc *hwdesc;
219 	dma_addr_t hwdesc_phys;
220 };
221 
222 struct stm32_mdma_desc {
223 	struct virt_dma_desc vdesc;
224 	u32 ccr;
225 	bool cyclic;
226 	u32 count;
227 	struct stm32_mdma_desc_node node[];
228 };
229 
230 struct stm32_mdma_dma_config {
231 	u32 request;	/* STM32 DMA channel stream id, triggering MDMA */
232 	u32 cmar;	/* STM32 DMA interrupt flag clear register address */
233 	u32 cmdr;	/* STM32 DMA Transfer Complete flag */
234 };
235 
236 struct stm32_mdma_chan {
237 	struct virt_dma_chan vchan;
238 	struct dma_pool *desc_pool;
239 	u32 id;
240 	struct stm32_mdma_desc *desc;
241 	u32 curr_hwdesc;
242 	struct dma_slave_config dma_config;
243 	struct stm32_mdma_chan_config chan_config;
244 	bool busy;
245 	u32 mem_burst;
246 	u32 mem_width;
247 };
248 
249 struct stm32_mdma_device {
250 	struct dma_device ddev;
251 	void __iomem *base;
252 	struct clk *clk;
253 	int irq;
254 	u32 nr_channels;
255 	u32 nr_requests;
256 	u32 nr_ahb_addr_masks;
257 	u32 chan_reserved;
258 	struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS];
259 	u32 ahb_addr_masks[];
260 };
261 
262 static struct stm32_mdma_device *stm32_mdma_get_dev(
263 	struct stm32_mdma_chan *chan)
264 {
265 	return container_of(chan->vchan.chan.device, struct stm32_mdma_device,
266 			    ddev);
267 }
268 
269 static struct stm32_mdma_chan *to_stm32_mdma_chan(struct dma_chan *c)
270 {
271 	return container_of(c, struct stm32_mdma_chan, vchan.chan);
272 }
273 
274 static struct stm32_mdma_desc *to_stm32_mdma_desc(struct virt_dma_desc *vdesc)
275 {
276 	return container_of(vdesc, struct stm32_mdma_desc, vdesc);
277 }
278 
279 static struct device *chan2dev(struct stm32_mdma_chan *chan)
280 {
281 	return &chan->vchan.chan.dev->device;
282 }
283 
284 static struct device *mdma2dev(struct stm32_mdma_device *mdma_dev)
285 {
286 	return mdma_dev->ddev.dev;
287 }
288 
289 static u32 stm32_mdma_read(struct stm32_mdma_device *dmadev, u32 reg)
290 {
291 	return readl_relaxed(dmadev->base + reg);
292 }
293 
294 static void stm32_mdma_write(struct stm32_mdma_device *dmadev, u32 reg, u32 val)
295 {
296 	writel_relaxed(val, dmadev->base + reg);
297 }
298 
299 static void stm32_mdma_set_bits(struct stm32_mdma_device *dmadev, u32 reg,
300 				u32 mask)
301 {
302 	void __iomem *addr = dmadev->base + reg;
303 
304 	writel_relaxed(readl_relaxed(addr) | mask, addr);
305 }
306 
307 static void stm32_mdma_clr_bits(struct stm32_mdma_device *dmadev, u32 reg,
308 				u32 mask)
309 {
310 	void __iomem *addr = dmadev->base + reg;
311 
312 	writel_relaxed(readl_relaxed(addr) & ~mask, addr);
313 }
314 
315 static struct stm32_mdma_desc *stm32_mdma_alloc_desc(
316 		struct stm32_mdma_chan *chan, u32 count)
317 {
318 	struct stm32_mdma_desc *desc;
319 	int i;
320 
321 	desc = kzalloc(struct_size(desc, node, count), GFP_NOWAIT);
322 	if (!desc)
323 		return NULL;
324 
325 	for (i = 0; i < count; i++) {
326 		desc->node[i].hwdesc =
327 			dma_pool_alloc(chan->desc_pool, GFP_NOWAIT,
328 				       &desc->node[i].hwdesc_phys);
329 		if (!desc->node[i].hwdesc)
330 			goto err;
331 	}
332 
333 	desc->count = count;
334 
335 	return desc;
336 
337 err:
338 	dev_err(chan2dev(chan), "Failed to allocate descriptor\n");
339 	while (--i >= 0)
340 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
341 			      desc->node[i].hwdesc_phys);
342 	kfree(desc);
343 	return NULL;
344 }
345 
346 static void stm32_mdma_desc_free(struct virt_dma_desc *vdesc)
347 {
348 	struct stm32_mdma_desc *desc = to_stm32_mdma_desc(vdesc);
349 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(vdesc->tx.chan);
350 	int i;
351 
352 	for (i = 0; i < desc->count; i++)
353 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
354 			      desc->node[i].hwdesc_phys);
355 	kfree(desc);
356 }
357 
358 static int stm32_mdma_get_width(struct stm32_mdma_chan *chan,
359 				enum dma_slave_buswidth width)
360 {
361 	switch (width) {
362 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
363 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
364 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
365 	case DMA_SLAVE_BUSWIDTH_8_BYTES:
366 		return ffs(width) - 1;
367 	default:
368 		dev_err(chan2dev(chan), "Dma bus width %i not supported\n",
369 			width);
370 		return -EINVAL;
371 	}
372 }
373 
374 static enum dma_slave_buswidth stm32_mdma_get_max_width(dma_addr_t addr,
375 							u32 buf_len, u32 tlen)
376 {
377 	enum dma_slave_buswidth max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
378 
379 	for (max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
380 	     max_width > DMA_SLAVE_BUSWIDTH_1_BYTE;
381 	     max_width >>= 1) {
382 		/*
383 		 * Address and buffer length both have to be aligned on
384 		 * bus width
385 		 */
386 		if ((((buf_len | addr) & (max_width - 1)) == 0) &&
387 		    tlen >= max_width)
388 			break;
389 	}
390 
391 	return max_width;
392 }
393 
394 static u32 stm32_mdma_get_best_burst(u32 buf_len, u32 tlen, u32 max_burst,
395 				     enum dma_slave_buswidth width)
396 {
397 	u32 best_burst;
398 
399 	best_burst = min((u32)1 << __ffs(tlen | buf_len),
400 			 max_burst * width) / width;
401 
402 	return (best_burst > 0) ? best_burst : 1;
403 }
404 
405 static int stm32_mdma_disable_chan(struct stm32_mdma_chan *chan)
406 {
407 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
408 	u32 ccr, cisr, id, reg;
409 	int ret;
410 
411 	id = chan->id;
412 	reg = STM32_MDMA_CCR(id);
413 
414 	/* Disable interrupts */
415 	stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_IRQ_MASK);
416 
417 	ccr = stm32_mdma_read(dmadev, reg);
418 	if (ccr & STM32_MDMA_CCR_EN) {
419 		stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_EN);
420 
421 		/* Ensure that any ongoing transfer has been completed */
422 		ret = readl_relaxed_poll_timeout_atomic(
423 				dmadev->base + STM32_MDMA_CISR(id), cisr,
424 				(cisr & STM32_MDMA_CISR_CTCIF), 10, 1000);
425 		if (ret) {
426 			dev_err(chan2dev(chan), "%s: timeout!\n", __func__);
427 			return -EBUSY;
428 		}
429 	}
430 
431 	return 0;
432 }
433 
434 static void stm32_mdma_stop(struct stm32_mdma_chan *chan)
435 {
436 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
437 	u32 status;
438 	int ret;
439 
440 	/* Disable DMA */
441 	ret = stm32_mdma_disable_chan(chan);
442 	if (ret < 0)
443 		return;
444 
445 	/* Clear interrupt status if it is there */
446 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
447 	if (status) {
448 		dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
449 			__func__, status);
450 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
451 	}
452 
453 	chan->busy = false;
454 }
455 
456 static void stm32_mdma_set_bus(struct stm32_mdma_device *dmadev, u32 *ctbr,
457 			       u32 ctbr_mask, u32 src_addr)
458 {
459 	u32 mask;
460 	int i;
461 
462 	/* Check if memory device is on AHB or AXI */
463 	*ctbr &= ~ctbr_mask;
464 	mask = src_addr & 0xF0000000;
465 	for (i = 0; i < dmadev->nr_ahb_addr_masks; i++) {
466 		if (mask == dmadev->ahb_addr_masks[i]) {
467 			*ctbr |= ctbr_mask;
468 			break;
469 		}
470 	}
471 }
472 
473 static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
474 				     enum dma_transfer_direction direction,
475 				     u32 *mdma_ccr, u32 *mdma_ctcr,
476 				     u32 *mdma_ctbr, dma_addr_t addr,
477 				     u32 buf_len)
478 {
479 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
480 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
481 	enum dma_slave_buswidth src_addr_width, dst_addr_width;
482 	phys_addr_t src_addr, dst_addr;
483 	int src_bus_width, dst_bus_width;
484 	u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
485 	u32 ccr, ctcr, ctbr, tlen;
486 
487 	src_addr_width = chan->dma_config.src_addr_width;
488 	dst_addr_width = chan->dma_config.dst_addr_width;
489 	src_maxburst = chan->dma_config.src_maxburst;
490 	dst_maxburst = chan->dma_config.dst_maxburst;
491 
492 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & ~STM32_MDMA_CCR_EN;
493 	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
494 	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
495 
496 	/* Enable HW request mode */
497 	ctcr &= ~STM32_MDMA_CTCR_SWRM;
498 
499 	/* Set DINC, SINC, DINCOS, SINCOS, TRGM and TLEN retrieve from DT */
500 	ctcr &= ~STM32_MDMA_CTCR_CFG_MASK;
501 	ctcr |= chan_config->transfer_config & STM32_MDMA_CTCR_CFG_MASK;
502 
503 	/*
504 	 * For buffer transfer length (TLEN) we have to set
505 	 * the number of bytes - 1 in CTCR register
506 	 */
507 	tlen = STM32_MDMA_CTCR_LEN2_GET(ctcr);
508 	ctcr &= ~STM32_MDMA_CTCR_LEN2_MSK;
509 	ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
510 
511 	/* Disable Pack Enable */
512 	ctcr &= ~STM32_MDMA_CTCR_PKE;
513 
514 	/* Check burst size constraints */
515 	if (src_maxburst * src_addr_width > STM32_MDMA_MAX_BURST ||
516 	    dst_maxburst * dst_addr_width > STM32_MDMA_MAX_BURST) {
517 		dev_err(chan2dev(chan),
518 			"burst size * bus width higher than %d bytes\n",
519 			STM32_MDMA_MAX_BURST);
520 		return -EINVAL;
521 	}
522 
523 	if ((!is_power_of_2(src_maxburst) && src_maxburst > 0) ||
524 	    (!is_power_of_2(dst_maxburst) && dst_maxburst > 0)) {
525 		dev_err(chan2dev(chan), "burst size must be a power of 2\n");
526 		return -EINVAL;
527 	}
528 
529 	/*
530 	 * Configure channel control:
531 	 * - Clear SW request as in this case this is a HW one
532 	 * - Clear WEX, HEX and BEX bits
533 	 * - Set priority level
534 	 */
535 	ccr &= ~(STM32_MDMA_CCR_SWRQ | STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
536 		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK);
537 	ccr |= STM32_MDMA_CCR_PL(chan_config->priority_level);
538 
539 	/* Configure Trigger selection */
540 	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
541 	ctbr |= STM32_MDMA_CTBR_TSEL(chan_config->request);
542 
543 	switch (direction) {
544 	case DMA_MEM_TO_DEV:
545 		dst_addr = chan->dma_config.dst_addr;
546 
547 		/* Set device data size */
548 		if (chan_config->m2m_hw)
549 			dst_addr_width = stm32_mdma_get_max_width(dst_addr, buf_len,
550 								  STM32_MDMA_MAX_BUF_LEN);
551 		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
552 		if (dst_bus_width < 0)
553 			return dst_bus_width;
554 		ctcr &= ~STM32_MDMA_CTCR_DSIZE_MASK;
555 		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width);
556 		if (chan_config->m2m_hw) {
557 			ctcr &= ~STM32_MDMA_CTCR_DINCOS_MASK;
558 			ctcr |= STM32_MDMA_CTCR_DINCOS(dst_bus_width);
559 		}
560 
561 		/* Set device burst value */
562 		if (chan_config->m2m_hw)
563 			dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;
564 
565 		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
566 							   dst_maxburst,
567 							   dst_addr_width);
568 		chan->mem_burst = dst_best_burst;
569 		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
570 		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
571 
572 		/* Set memory data size */
573 		src_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
574 		chan->mem_width = src_addr_width;
575 		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
576 		if (src_bus_width < 0)
577 			return src_bus_width;
578 		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK |
579 			STM32_MDMA_CTCR_SINCOS_MASK;
580 		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width) |
581 			STM32_MDMA_CTCR_SINCOS(src_bus_width);
582 
583 		/* Set memory burst value */
584 		src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;
585 		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
586 							   src_maxburst,
587 							   src_addr_width);
588 		chan->mem_burst = src_best_burst;
589 		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
590 		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
591 
592 		/* Select bus */
593 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
594 				   dst_addr);
595 
596 		if (dst_bus_width != src_bus_width)
597 			ctcr |= STM32_MDMA_CTCR_PKE;
598 
599 		/* Set destination address */
600 		stm32_mdma_write(dmadev, STM32_MDMA_CDAR(chan->id), dst_addr);
601 		break;
602 
603 	case DMA_DEV_TO_MEM:
604 		src_addr = chan->dma_config.src_addr;
605 
606 		/* Set device data size */
607 		if (chan_config->m2m_hw)
608 			src_addr_width = stm32_mdma_get_max_width(src_addr, buf_len,
609 								  STM32_MDMA_MAX_BUF_LEN);
610 
611 		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
612 		if (src_bus_width < 0)
613 			return src_bus_width;
614 		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK;
615 		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width);
616 		if (chan_config->m2m_hw) {
617 			ctcr &= ~STM32_MDMA_CTCR_SINCOS_MASK;
618 			ctcr |= STM32_MDMA_CTCR_SINCOS(src_bus_width);
619 		}
620 
621 		/* Set device burst value */
622 		if (chan_config->m2m_hw)
623 			src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;
624 
625 		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
626 							   src_maxburst,
627 							   src_addr_width);
628 		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
629 		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
630 
631 		/* Set memory data size */
632 		dst_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
633 		chan->mem_width = dst_addr_width;
634 		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
635 		if (dst_bus_width < 0)
636 			return dst_bus_width;
637 		ctcr &= ~(STM32_MDMA_CTCR_DSIZE_MASK |
638 			STM32_MDMA_CTCR_DINCOS_MASK);
639 		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
640 			STM32_MDMA_CTCR_DINCOS(dst_bus_width);
641 
642 		/* Set memory burst value */
643 		dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;
644 		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
645 							   dst_maxburst,
646 							   dst_addr_width);
647 		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
648 		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
649 
650 		/* Select bus */
651 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
652 				   src_addr);
653 
654 		if (dst_bus_width != src_bus_width)
655 			ctcr |= STM32_MDMA_CTCR_PKE;
656 
657 		/* Set source address */
658 		stm32_mdma_write(dmadev, STM32_MDMA_CSAR(chan->id), src_addr);
659 		break;
660 
661 	default:
662 		dev_err(chan2dev(chan), "Dma direction is not supported\n");
663 		return -EINVAL;
664 	}
665 
666 	*mdma_ccr = ccr;
667 	*mdma_ctcr = ctcr;
668 	*mdma_ctbr = ctbr;
669 
670 	return 0;
671 }
672 
673 static void stm32_mdma_dump_hwdesc(struct stm32_mdma_chan *chan,
674 				   struct stm32_mdma_desc_node *node)
675 {
676 	dev_dbg(chan2dev(chan), "hwdesc:  %pad\n", &node->hwdesc_phys);
677 	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n", node->hwdesc->ctcr);
678 	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n", node->hwdesc->cbndtr);
679 	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n", node->hwdesc->csar);
680 	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n", node->hwdesc->cdar);
681 	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n", node->hwdesc->cbrur);
682 	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n", node->hwdesc->clar);
683 	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n", node->hwdesc->ctbr);
684 	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n", node->hwdesc->cmar);
685 	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n\n", node->hwdesc->cmdr);
686 }
687 
688 static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
689 				    struct stm32_mdma_desc *desc,
690 				    enum dma_transfer_direction dir, u32 count,
691 				    dma_addr_t src_addr, dma_addr_t dst_addr,
692 				    u32 len, u32 ctcr, u32 ctbr, bool is_last,
693 				    bool is_first, bool is_cyclic)
694 {
695 	struct stm32_mdma_chan_config *config = &chan->chan_config;
696 	struct stm32_mdma_hwdesc *hwdesc;
697 	u32 next = count + 1;
698 
699 	hwdesc = desc->node[count].hwdesc;
700 	hwdesc->ctcr = ctcr;
701 	hwdesc->cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK |
702 			STM32_MDMA_CBNDTR_BRDUM |
703 			STM32_MDMA_CBNDTR_BRSUM |
704 			STM32_MDMA_CBNDTR_BNDT_MASK);
705 	hwdesc->cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
706 	hwdesc->csar = src_addr;
707 	hwdesc->cdar = dst_addr;
708 	hwdesc->cbrur = 0;
709 	hwdesc->ctbr = ctbr;
710 	hwdesc->cmar = config->mask_addr;
711 	hwdesc->cmdr = config->mask_data;
712 
713 	if (is_last) {
714 		if (is_cyclic)
715 			hwdesc->clar = desc->node[0].hwdesc_phys;
716 		else
717 			hwdesc->clar = 0;
718 	} else {
719 		hwdesc->clar = desc->node[next].hwdesc_phys;
720 	}
721 
722 	stm32_mdma_dump_hwdesc(chan, &desc->node[count]);
723 }
724 
725 static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
726 				 struct stm32_mdma_desc *desc,
727 				 struct scatterlist *sgl, u32 sg_len,
728 				 enum dma_transfer_direction direction)
729 {
730 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
731 	struct dma_slave_config *dma_config = &chan->dma_config;
732 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
733 	struct scatterlist *sg;
734 	dma_addr_t src_addr, dst_addr;
735 	u32 m2m_hw_period, ccr, ctcr, ctbr;
736 	int i, ret = 0;
737 
738 	if (chan_config->m2m_hw)
739 		m2m_hw_period = sg_dma_len(sgl);
740 
741 	for_each_sg(sgl, sg, sg_len, i) {
742 		if (sg_dma_len(sg) > STM32_MDMA_MAX_BLOCK_LEN) {
743 			dev_err(chan2dev(chan), "Invalid block len\n");
744 			return -EINVAL;
745 		}
746 
747 		if (direction == DMA_MEM_TO_DEV) {
748 			src_addr = sg_dma_address(sg);
749 			dst_addr = dma_config->dst_addr;
750 			if (chan_config->m2m_hw && (i & 1))
751 				dst_addr += m2m_hw_period;
752 			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
753 							&ctcr, &ctbr, src_addr,
754 							sg_dma_len(sg));
755 			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
756 					   src_addr);
757 		} else {
758 			src_addr = dma_config->src_addr;
759 			if (chan_config->m2m_hw && (i & 1))
760 				src_addr += m2m_hw_period;
761 			dst_addr = sg_dma_address(sg);
762 			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
763 							&ctcr, &ctbr, dst_addr,
764 							sg_dma_len(sg));
765 			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
766 					   dst_addr);
767 		}
768 
769 		if (ret < 0)
770 			return ret;
771 
772 		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
773 					dst_addr, sg_dma_len(sg), ctcr, ctbr,
774 					i == sg_len - 1, i == 0, false);
775 	}
776 
777 	/* Enable interrupts */
778 	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
779 	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE;
780 	desc->ccr = ccr;
781 
782 	return 0;
783 }
784 
785 static struct dma_async_tx_descriptor *
786 stm32_mdma_prep_slave_sg(struct dma_chan *c, struct scatterlist *sgl,
787 			 u32 sg_len, enum dma_transfer_direction direction,
788 			 unsigned long flags, void *context)
789 {
790 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
791 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
792 	struct stm32_mdma_desc *desc;
793 	int i, ret;
794 
795 	/*
796 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
797 	 * channel anymore. The DMA channel needs to be aborted or terminated
798 	 * for allowing another request.
799 	 */
800 	if (chan->desc && chan->desc->cyclic) {
801 		dev_err(chan2dev(chan),
802 			"Request not allowed when dma in cyclic mode\n");
803 		return NULL;
804 	}
805 
806 	desc = stm32_mdma_alloc_desc(chan, sg_len);
807 	if (!desc)
808 		return NULL;
809 
810 	ret = stm32_mdma_setup_xfer(chan, desc, sgl, sg_len, direction);
811 	if (ret < 0)
812 		goto xfer_setup_err;
813 
814 	/*
815 	 * In case of M2M HW transfer triggered by STM32 DMA, we do not have to clear the
816 	 * transfer complete flag by hardware in order to let the CPU rearm the STM32 DMA
817 	 * with the next sg element and update some data in dmaengine framework.
818 	 */
819 	if (chan_config->m2m_hw && direction == DMA_MEM_TO_DEV) {
820 		struct stm32_mdma_hwdesc *hwdesc;
821 
822 		for (i = 0; i < sg_len; i++) {
823 			hwdesc = desc->node[i].hwdesc;
824 			hwdesc->cmar = 0;
825 			hwdesc->cmdr = 0;
826 		}
827 	}
828 
829 	desc->cyclic = false;
830 
831 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
832 
833 xfer_setup_err:
834 	for (i = 0; i < desc->count; i++)
835 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
836 			      desc->node[i].hwdesc_phys);
837 	kfree(desc);
838 	return NULL;
839 }
840 
841 static struct dma_async_tx_descriptor *
842 stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
843 			   size_t buf_len, size_t period_len,
844 			   enum dma_transfer_direction direction,
845 			   unsigned long flags)
846 {
847 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
848 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
849 	struct dma_slave_config *dma_config = &chan->dma_config;
850 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
851 	struct stm32_mdma_desc *desc;
852 	dma_addr_t src_addr, dst_addr;
853 	u32 ccr, ctcr, ctbr, count;
854 	int i, ret;
855 
856 	/*
857 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
858 	 * channel anymore. The DMA channel needs to be aborted or terminated
859 	 * for allowing another request.
860 	 */
861 	if (chan->desc && chan->desc->cyclic) {
862 		dev_err(chan2dev(chan),
863 			"Request not allowed when dma in cyclic mode\n");
864 		return NULL;
865 	}
866 
867 	if (!buf_len || !period_len || period_len > STM32_MDMA_MAX_BLOCK_LEN) {
868 		dev_err(chan2dev(chan), "Invalid buffer/period len\n");
869 		return NULL;
870 	}
871 
872 	if (buf_len % period_len) {
873 		dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
874 		return NULL;
875 	}
876 
877 	count = buf_len / period_len;
878 
879 	desc = stm32_mdma_alloc_desc(chan, count);
880 	if (!desc)
881 		return NULL;
882 
883 	/* Select bus */
884 	if (direction == DMA_MEM_TO_DEV) {
885 		src_addr = buf_addr;
886 		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
887 						&ctbr, src_addr, period_len);
888 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
889 				   src_addr);
890 	} else {
891 		dst_addr = buf_addr;
892 		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
893 						&ctbr, dst_addr, period_len);
894 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
895 				   dst_addr);
896 	}
897 
898 	if (ret < 0)
899 		goto xfer_setup_err;
900 
901 	/* Enable interrupts */
902 	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
903 	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
904 	desc->ccr = ccr;
905 
906 	/* Configure hwdesc list */
907 	for (i = 0; i < count; i++) {
908 		if (direction == DMA_MEM_TO_DEV) {
909 			src_addr = buf_addr + i * period_len;
910 			dst_addr = dma_config->dst_addr;
911 			if (chan_config->m2m_hw && (i & 1))
912 				dst_addr += period_len;
913 		} else {
914 			src_addr = dma_config->src_addr;
915 			if (chan_config->m2m_hw && (i & 1))
916 				src_addr += period_len;
917 			dst_addr = buf_addr + i * period_len;
918 		}
919 
920 		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
921 					dst_addr, period_len, ctcr, ctbr,
922 					i == count - 1, i == 0, true);
923 	}
924 
925 	desc->cyclic = true;
926 
927 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
928 
929 xfer_setup_err:
930 	for (i = 0; i < desc->count; i++)
931 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
932 			      desc->node[i].hwdesc_phys);
933 	kfree(desc);
934 	return NULL;
935 }
936 
937 static struct dma_async_tx_descriptor *
938 stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
939 			   size_t len, unsigned long flags)
940 {
941 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
942 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
943 	enum dma_slave_buswidth max_width;
944 	struct stm32_mdma_desc *desc;
945 	struct stm32_mdma_hwdesc *hwdesc;
946 	u32 ccr, ctcr, ctbr, cbndtr, count, max_burst, mdma_burst;
947 	u32 best_burst, tlen;
948 	size_t xfer_count, offset;
949 	int src_bus_width, dst_bus_width;
950 	int i;
951 
952 	/*
953 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
954 	 * channel anymore. The DMA channel needs to be aborted or terminated
955 	 * to allow another request
956 	 */
957 	if (chan->desc && chan->desc->cyclic) {
958 		dev_err(chan2dev(chan),
959 			"Request not allowed when dma in cyclic mode\n");
960 		return NULL;
961 	}
962 
963 	count = DIV_ROUND_UP(len, STM32_MDMA_MAX_BLOCK_LEN);
964 	desc = stm32_mdma_alloc_desc(chan, count);
965 	if (!desc)
966 		return NULL;
967 
968 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & ~STM32_MDMA_CCR_EN;
969 	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
970 	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
971 	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
972 
973 	/* Enable sw req, some interrupts and clear other bits */
974 	ccr &= ~(STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
975 		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK |
976 		 STM32_MDMA_CCR_IRQ_MASK);
977 	ccr |= STM32_MDMA_CCR_TEIE;
978 
979 	/* Enable SW request mode, dest/src inc and clear other bits */
980 	ctcr &= ~(STM32_MDMA_CTCR_BWM | STM32_MDMA_CTCR_TRGM_MSK |
981 		  STM32_MDMA_CTCR_PAM_MASK | STM32_MDMA_CTCR_PKE |
982 		  STM32_MDMA_CTCR_TLEN_MSK | STM32_MDMA_CTCR_DBURST_MASK |
983 		  STM32_MDMA_CTCR_SBURST_MASK | STM32_MDMA_CTCR_DINCOS_MASK |
984 		  STM32_MDMA_CTCR_SINCOS_MASK | STM32_MDMA_CTCR_DSIZE_MASK |
985 		  STM32_MDMA_CTCR_SSIZE_MASK | STM32_MDMA_CTCR_DINC_MASK |
986 		  STM32_MDMA_CTCR_SINC_MASK);
987 	ctcr |= STM32_MDMA_CTCR_SWRM | STM32_MDMA_CTCR_SINC(STM32_MDMA_INC) |
988 		STM32_MDMA_CTCR_DINC(STM32_MDMA_INC);
989 
990 	/* Reset HW request */
991 	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
992 
993 	/* Select bus */
994 	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS, src);
995 	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS, dest);
996 
997 	/* Clear CBNDTR registers */
998 	cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK | STM32_MDMA_CBNDTR_BRDUM |
999 			STM32_MDMA_CBNDTR_BRSUM | STM32_MDMA_CBNDTR_BNDT_MASK);
1000 
1001 	if (len <= STM32_MDMA_MAX_BLOCK_LEN) {
1002 		cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
1003 		if (len <= STM32_MDMA_MAX_BUF_LEN) {
1004 			/* Setup a buffer transfer */
1005 			ccr |= STM32_MDMA_CCR_TCIE | STM32_MDMA_CCR_CTCIE;
1006 			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BUFFER);
1007 		} else {
1008 			/* Setup a block transfer */
1009 			ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
1010 			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BLOCK);
1011 		}
1012 
1013 		tlen = STM32_MDMA_MAX_BUF_LEN;
1014 		ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
1015 
1016 		/* Set source best burst size */
1017 		max_width = stm32_mdma_get_max_width(src, len, tlen);
1018 		src_bus_width = stm32_mdma_get_width(chan, max_width);
1019 
1020 		max_burst = tlen / max_width;
1021 		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
1022 						       max_width);
1023 		mdma_burst = ilog2(best_burst);
1024 
1025 		ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
1026 			STM32_MDMA_CTCR_SSIZE(src_bus_width) |
1027 			STM32_MDMA_CTCR_SINCOS(src_bus_width);
1028 
1029 		/* Set destination best burst size */
1030 		max_width = stm32_mdma_get_max_width(dest, len, tlen);
1031 		dst_bus_width = stm32_mdma_get_width(chan, max_width);
1032 
1033 		max_burst = tlen / max_width;
1034 		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
1035 						       max_width);
1036 		mdma_burst = ilog2(best_burst);
1037 
1038 		ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
1039 			STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
1040 			STM32_MDMA_CTCR_DINCOS(dst_bus_width);
1041 
1042 		if (dst_bus_width != src_bus_width)
1043 			ctcr |= STM32_MDMA_CTCR_PKE;
1044 
1045 		/* Prepare hardware descriptor */
1046 		hwdesc = desc->node[0].hwdesc;
1047 		hwdesc->ctcr = ctcr;
1048 		hwdesc->cbndtr = cbndtr;
1049 		hwdesc->csar = src;
1050 		hwdesc->cdar = dest;
1051 		hwdesc->cbrur = 0;
1052 		hwdesc->clar = 0;
1053 		hwdesc->ctbr = ctbr;
1054 		hwdesc->cmar = 0;
1055 		hwdesc->cmdr = 0;
1056 
1057 		stm32_mdma_dump_hwdesc(chan, &desc->node[0]);
1058 	} else {
1059 		/* Setup a LLI transfer */
1060 		ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_LINKED_LIST) |
1061 			STM32_MDMA_CTCR_TLEN((STM32_MDMA_MAX_BUF_LEN - 1));
1062 		ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
1063 		tlen = STM32_MDMA_MAX_BUF_LEN;
1064 
1065 		for (i = 0, offset = 0; offset < len;
1066 		     i++, offset += xfer_count) {
1067 			xfer_count = min_t(size_t, len - offset,
1068 					   STM32_MDMA_MAX_BLOCK_LEN);
1069 
1070 			/* Set source best burst size */
1071 			max_width = stm32_mdma_get_max_width(src, len, tlen);
1072 			src_bus_width = stm32_mdma_get_width(chan, max_width);
1073 
1074 			max_burst = tlen / max_width;
1075 			best_burst = stm32_mdma_get_best_burst(len, tlen,
1076 							       max_burst,
1077 							       max_width);
1078 			mdma_burst = ilog2(best_burst);
1079 
1080 			ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
1081 				STM32_MDMA_CTCR_SSIZE(src_bus_width) |
1082 				STM32_MDMA_CTCR_SINCOS(src_bus_width);
1083 
1084 			/* Set destination best burst size */
1085 			max_width = stm32_mdma_get_max_width(dest, len, tlen);
1086 			dst_bus_width = stm32_mdma_get_width(chan, max_width);
1087 
1088 			max_burst = tlen / max_width;
1089 			best_burst = stm32_mdma_get_best_burst(len, tlen,
1090 							       max_burst,
1091 							       max_width);
1092 			mdma_burst = ilog2(best_burst);
1093 
1094 			ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
1095 				STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
1096 				STM32_MDMA_CTCR_DINCOS(dst_bus_width);
1097 
1098 			if (dst_bus_width != src_bus_width)
1099 				ctcr |= STM32_MDMA_CTCR_PKE;
1100 
1101 			/* Prepare hardware descriptor */
1102 			stm32_mdma_setup_hwdesc(chan, desc, DMA_MEM_TO_MEM, i,
1103 						src + offset, dest + offset,
1104 						xfer_count, ctcr, ctbr,
1105 						i == count - 1, i == 0, false);
1106 		}
1107 	}
1108 
1109 	desc->ccr = ccr;
1110 
1111 	desc->cyclic = false;
1112 
1113 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1114 }
1115 
1116 static void stm32_mdma_dump_reg(struct stm32_mdma_chan *chan)
1117 {
1118 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1119 
1120 	dev_dbg(chan2dev(chan), "CCR:     0x%08x\n",
1121 		stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)));
1122 	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n",
1123 		stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id)));
1124 	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n",
1125 		stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id)));
1126 	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n",
1127 		stm32_mdma_read(dmadev, STM32_MDMA_CSAR(chan->id)));
1128 	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n",
1129 		stm32_mdma_read(dmadev, STM32_MDMA_CDAR(chan->id)));
1130 	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n",
1131 		stm32_mdma_read(dmadev, STM32_MDMA_CBRUR(chan->id)));
1132 	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n",
1133 		stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id)));
1134 	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n",
1135 		stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id)));
1136 	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n",
1137 		stm32_mdma_read(dmadev, STM32_MDMA_CMAR(chan->id)));
1138 	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n",
1139 		stm32_mdma_read(dmadev, STM32_MDMA_CMDR(chan->id)));
1140 }
1141 
1142 static void stm32_mdma_start_transfer(struct stm32_mdma_chan *chan)
1143 {
1144 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1145 	struct virt_dma_desc *vdesc;
1146 	struct stm32_mdma_hwdesc *hwdesc;
1147 	u32 id = chan->id;
1148 	u32 status, reg;
1149 
1150 	vdesc = vchan_next_desc(&chan->vchan);
1151 	if (!vdesc) {
1152 		chan->desc = NULL;
1153 		return;
1154 	}
1155 
1156 	list_del(&vdesc->node);
1157 
1158 	chan->desc = to_stm32_mdma_desc(vdesc);
1159 	hwdesc = chan->desc->node[0].hwdesc;
1160 	chan->curr_hwdesc = 0;
1161 
1162 	stm32_mdma_write(dmadev, STM32_MDMA_CCR(id), chan->desc->ccr);
1163 	stm32_mdma_write(dmadev, STM32_MDMA_CTCR(id), hwdesc->ctcr);
1164 	stm32_mdma_write(dmadev, STM32_MDMA_CBNDTR(id), hwdesc->cbndtr);
1165 	stm32_mdma_write(dmadev, STM32_MDMA_CSAR(id), hwdesc->csar);
1166 	stm32_mdma_write(dmadev, STM32_MDMA_CDAR(id), hwdesc->cdar);
1167 	stm32_mdma_write(dmadev, STM32_MDMA_CBRUR(id), hwdesc->cbrur);
1168 	stm32_mdma_write(dmadev, STM32_MDMA_CLAR(id), hwdesc->clar);
1169 	stm32_mdma_write(dmadev, STM32_MDMA_CTBR(id), hwdesc->ctbr);
1170 	stm32_mdma_write(dmadev, STM32_MDMA_CMAR(id), hwdesc->cmar);
1171 	stm32_mdma_write(dmadev, STM32_MDMA_CMDR(id), hwdesc->cmdr);
1172 
1173 	/* Clear interrupt status if it is there */
1174 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
1175 	if (status)
1176 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(id), status);
1177 
1178 	stm32_mdma_dump_reg(chan);
1179 
1180 	/* Start DMA */
1181 	stm32_mdma_set_bits(dmadev, STM32_MDMA_CCR(id), STM32_MDMA_CCR_EN);
1182 
1183 	/* Set SW request in case of MEM2MEM transfer */
1184 	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM) {
1185 		reg = STM32_MDMA_CCR(id);
1186 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
1187 	}
1188 
1189 	chan->busy = true;
1190 
1191 	dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
1192 }
1193 
1194 static void stm32_mdma_issue_pending(struct dma_chan *c)
1195 {
1196 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1197 	unsigned long flags;
1198 
1199 	spin_lock_irqsave(&chan->vchan.lock, flags);
1200 
1201 	if (!vchan_issue_pending(&chan->vchan))
1202 		goto end;
1203 
1204 	dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
1205 
1206 	if (!chan->desc && !chan->busy)
1207 		stm32_mdma_start_transfer(chan);
1208 
1209 end:
1210 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1211 }
1212 
1213 static int stm32_mdma_pause(struct dma_chan *c)
1214 {
1215 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1216 	unsigned long flags;
1217 	int ret;
1218 
1219 	spin_lock_irqsave(&chan->vchan.lock, flags);
1220 	ret = stm32_mdma_disable_chan(chan);
1221 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1222 
1223 	if (!ret)
1224 		dev_dbg(chan2dev(chan), "vchan %pK: pause\n", &chan->vchan);
1225 
1226 	return ret;
1227 }
1228 
1229 static int stm32_mdma_resume(struct dma_chan *c)
1230 {
1231 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1232 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1233 	struct stm32_mdma_hwdesc *hwdesc;
1234 	unsigned long flags;
1235 	u32 status, reg;
1236 
1237 	/* Transfer can be terminated */
1238 	if (!chan->desc || (stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & STM32_MDMA_CCR_EN))
1239 		return -EPERM;
1240 
1241 	hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc;
1242 
1243 	spin_lock_irqsave(&chan->vchan.lock, flags);
1244 
1245 	/* Re-configure control register */
1246 	stm32_mdma_write(dmadev, STM32_MDMA_CCR(chan->id), chan->desc->ccr);
1247 
1248 	/* Clear interrupt status if it is there */
1249 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
1250 	if (status)
1251 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
1252 
1253 	stm32_mdma_dump_reg(chan);
1254 
1255 	/* Re-start DMA */
1256 	reg = STM32_MDMA_CCR(chan->id);
1257 	stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_EN);
1258 
1259 	/* Set SW request in case of MEM2MEM transfer */
1260 	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM)
1261 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
1262 
1263 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1264 
1265 	dev_dbg(chan2dev(chan), "vchan %pK: resume\n", &chan->vchan);
1266 
1267 	return 0;
1268 }
1269 
1270 static int stm32_mdma_terminate_all(struct dma_chan *c)
1271 {
1272 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1273 	unsigned long flags;
1274 	LIST_HEAD(head);
1275 
1276 	spin_lock_irqsave(&chan->vchan.lock, flags);
1277 	if (chan->desc) {
1278 		vchan_terminate_vdesc(&chan->desc->vdesc);
1279 		if (chan->busy)
1280 			stm32_mdma_stop(chan);
1281 		chan->desc = NULL;
1282 	}
1283 	vchan_get_all_descriptors(&chan->vchan, &head);
1284 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1285 
1286 	vchan_dma_desc_free_list(&chan->vchan, &head);
1287 
1288 	return 0;
1289 }
1290 
1291 static void stm32_mdma_synchronize(struct dma_chan *c)
1292 {
1293 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1294 
1295 	vchan_synchronize(&chan->vchan);
1296 }
1297 
1298 static int stm32_mdma_slave_config(struct dma_chan *c,
1299 				   struct dma_slave_config *config)
1300 {
1301 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1302 
1303 	memcpy(&chan->dma_config, config, sizeof(*config));
1304 
1305 	/* Check if user is requesting STM32 DMA to trigger MDMA */
1306 	if (config->peripheral_size) {
1307 		struct stm32_mdma_dma_config *mdma_config;
1308 
1309 		mdma_config = (struct stm32_mdma_dma_config *)chan->dma_config.peripheral_config;
1310 		chan->chan_config.request = mdma_config->request;
1311 		chan->chan_config.mask_addr = mdma_config->cmar;
1312 		chan->chan_config.mask_data = mdma_config->cmdr;
1313 		chan->chan_config.m2m_hw = true;
1314 	}
1315 
1316 	return 0;
1317 }
1318 
1319 static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
1320 				      struct stm32_mdma_desc *desc,
1321 				      u32 curr_hwdesc,
1322 				      struct dma_tx_state *state)
1323 {
1324 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1325 	struct stm32_mdma_hwdesc *hwdesc;
1326 	u32 cisr, clar, cbndtr, residue, modulo, burst_size;
1327 	int i;
1328 
1329 	cisr = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
1330 
1331 	residue = 0;
1332 	/* Get the next hw descriptor to process from current transfer */
1333 	clar = stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id));
1334 	for (i = desc->count - 1; i >= 0; i--) {
1335 		hwdesc = desc->node[i].hwdesc;
1336 
1337 		if (hwdesc->clar == clar)
1338 			break;/* Current transfer found, stop cumulating */
1339 
1340 		/* Cumulate residue of unprocessed hw descriptors */
1341 		residue += STM32_MDMA_CBNDTR_BNDT(hwdesc->cbndtr);
1342 	}
1343 	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
1344 	residue += cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
1345 
1346 	state->in_flight_bytes = 0;
1347 	if (chan->chan_config.m2m_hw && (cisr & STM32_MDMA_CISR_CRQA))
1348 		state->in_flight_bytes = cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
1349 
1350 	if (!chan->mem_burst)
1351 		return residue;
1352 
1353 	burst_size = chan->mem_burst * chan->mem_width;
1354 	modulo = residue % burst_size;
1355 	if (modulo)
1356 		residue = residue - modulo + burst_size;
1357 
1358 	return residue;
1359 }
1360 
1361 static enum dma_status stm32_mdma_tx_status(struct dma_chan *c,
1362 					    dma_cookie_t cookie,
1363 					    struct dma_tx_state *state)
1364 {
1365 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1366 	struct virt_dma_desc *vdesc;
1367 	enum dma_status status;
1368 	unsigned long flags;
1369 	u32 residue = 0;
1370 
1371 	status = dma_cookie_status(c, cookie, state);
1372 	if ((status == DMA_COMPLETE) || (!state))
1373 		return status;
1374 
1375 	spin_lock_irqsave(&chan->vchan.lock, flags);
1376 
1377 	vdesc = vchan_find_desc(&chan->vchan, cookie);
1378 	if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1379 		residue = stm32_mdma_desc_residue(chan, chan->desc, chan->curr_hwdesc, state);
1380 	else if (vdesc)
1381 		residue = stm32_mdma_desc_residue(chan, to_stm32_mdma_desc(vdesc), 0, state);
1382 
1383 	dma_set_residue(state, residue);
1384 
1385 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1386 
1387 	return status;
1388 }
1389 
1390 static void stm32_mdma_xfer_end(struct stm32_mdma_chan *chan)
1391 {
1392 	vchan_cookie_complete(&chan->desc->vdesc);
1393 	chan->desc = NULL;
1394 	chan->busy = false;
1395 
1396 	/* Start the next transfer if this driver has a next desc */
1397 	stm32_mdma_start_transfer(chan);
1398 }
1399 
1400 static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)
1401 {
1402 	struct stm32_mdma_device *dmadev = devid;
1403 	struct stm32_mdma_chan *chan;
1404 	u32 reg, id, ccr, ien, status;
1405 
1406 	/* Find out which channel generates the interrupt */
1407 	status = readl_relaxed(dmadev->base + STM32_MDMA_GISR0);
1408 	if (!status) {
1409 		dev_dbg(mdma2dev(dmadev), "spurious it\n");
1410 		return IRQ_NONE;
1411 	}
1412 	id = __ffs(status);
1413 	chan = &dmadev->chan[id];
1414 
1415 	/* Handle interrupt for the channel */
1416 	spin_lock(&chan->vchan.lock);
1417 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
1418 	/* Mask Channel ReQuest Active bit which can be set in case of MEM2MEM */
1419 	status &= ~STM32_MDMA_CISR_CRQA;
1420 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
1421 	ien = (ccr & STM32_MDMA_CCR_IRQ_MASK) >> 1;
1422 
1423 	if (!(status & ien)) {
1424 		spin_unlock(&chan->vchan.lock);
1425 		if (chan->busy)
1426 			dev_warn(chan2dev(chan),
1427 				 "spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
1428 		else
1429 			dev_dbg(chan2dev(chan),
1430 				"spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
1431 		return IRQ_NONE;
1432 	}
1433 
1434 	reg = STM32_MDMA_CIFCR(id);
1435 
1436 	if (status & STM32_MDMA_CISR_TEIF) {
1437 		dev_err(chan2dev(chan), "Transfer Err: stat=0x%08x\n",
1438 			readl_relaxed(dmadev->base + STM32_MDMA_CESR(id)));
1439 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CTEIF);
1440 		status &= ~STM32_MDMA_CISR_TEIF;
1441 	}
1442 
1443 	if (status & STM32_MDMA_CISR_CTCIF) {
1444 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CCTCIF);
1445 		status &= ~STM32_MDMA_CISR_CTCIF;
1446 		stm32_mdma_xfer_end(chan);
1447 	}
1448 
1449 	if (status & STM32_MDMA_CISR_BRTIF) {
1450 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBRTIF);
1451 		status &= ~STM32_MDMA_CISR_BRTIF;
1452 	}
1453 
1454 	if (status & STM32_MDMA_CISR_BTIF) {
1455 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBTIF);
1456 		status &= ~STM32_MDMA_CISR_BTIF;
1457 		chan->curr_hwdesc++;
1458 		if (chan->desc && chan->desc->cyclic) {
1459 			if (chan->curr_hwdesc == chan->desc->count)
1460 				chan->curr_hwdesc = 0;
1461 			vchan_cyclic_callback(&chan->desc->vdesc);
1462 		}
1463 	}
1464 
1465 	if (status & STM32_MDMA_CISR_TCIF) {
1466 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CLTCIF);
1467 		status &= ~STM32_MDMA_CISR_TCIF;
1468 	}
1469 
1470 	if (status) {
1471 		stm32_mdma_set_bits(dmadev, reg, status);
1472 		dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
1473 		if (!(ccr & STM32_MDMA_CCR_EN))
1474 			dev_err(chan2dev(chan), "chan disabled by HW\n");
1475 	}
1476 
1477 	spin_unlock(&chan->vchan.lock);
1478 
1479 	return IRQ_HANDLED;
1480 }
1481 
1482 static int stm32_mdma_alloc_chan_resources(struct dma_chan *c)
1483 {
1484 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1485 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1486 	int ret;
1487 
1488 	chan->desc_pool = dmam_pool_create(dev_name(&c->dev->device),
1489 					   c->device->dev,
1490 					   sizeof(struct stm32_mdma_hwdesc),
1491 					  __alignof__(struct stm32_mdma_hwdesc),
1492 					   0);
1493 	if (!chan->desc_pool) {
1494 		dev_err(chan2dev(chan), "failed to allocate descriptor pool\n");
1495 		return -ENOMEM;
1496 	}
1497 
1498 	ret = pm_runtime_resume_and_get(dmadev->ddev.dev);
1499 	if (ret < 0)
1500 		return ret;
1501 
1502 	ret = stm32_mdma_disable_chan(chan);
1503 	if (ret < 0)
1504 		pm_runtime_put(dmadev->ddev.dev);
1505 
1506 	return ret;
1507 }
1508 
1509 static void stm32_mdma_free_chan_resources(struct dma_chan *c)
1510 {
1511 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1512 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1513 	unsigned long flags;
1514 
1515 	dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1516 
1517 	if (chan->busy) {
1518 		spin_lock_irqsave(&chan->vchan.lock, flags);
1519 		stm32_mdma_stop(chan);
1520 		chan->desc = NULL;
1521 		spin_unlock_irqrestore(&chan->vchan.lock, flags);
1522 	}
1523 
1524 	pm_runtime_put(dmadev->ddev.dev);
1525 	vchan_free_chan_resources(to_virt_chan(c));
1526 	dmam_pool_destroy(chan->desc_pool);
1527 	chan->desc_pool = NULL;
1528 }
1529 
1530 static bool stm32_mdma_filter_fn(struct dma_chan *c, void *fn_param)
1531 {
1532 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1533 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1534 
1535 	/* Check if chan is marked Secure */
1536 	if (dmadev->chan_reserved & BIT(chan->id))
1537 		return false;
1538 
1539 	return true;
1540 }
1541 
1542 static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
1543 					    struct of_dma *ofdma)
1544 {
1545 	struct stm32_mdma_device *dmadev = ofdma->of_dma_data;
1546 	dma_cap_mask_t mask = dmadev->ddev.cap_mask;
1547 	struct stm32_mdma_chan *chan;
1548 	struct dma_chan *c;
1549 	struct stm32_mdma_chan_config config;
1550 
1551 	if (dma_spec->args_count < 5) {
1552 		dev_err(mdma2dev(dmadev), "Bad number of args\n");
1553 		return NULL;
1554 	}
1555 
1556 	memset(&config, 0, sizeof(config));
1557 	config.request = dma_spec->args[0];
1558 	config.priority_level = dma_spec->args[1];
1559 	config.transfer_config = dma_spec->args[2];
1560 	config.mask_addr = dma_spec->args[3];
1561 	config.mask_data = dma_spec->args[4];
1562 
1563 	if (config.request >= dmadev->nr_requests) {
1564 		dev_err(mdma2dev(dmadev), "Bad request line\n");
1565 		return NULL;
1566 	}
1567 
1568 	if (config.priority_level > STM32_MDMA_VERY_HIGH_PRIORITY) {
1569 		dev_err(mdma2dev(dmadev), "Priority level not supported\n");
1570 		return NULL;
1571 	}
1572 
1573 	c = __dma_request_channel(&mask, stm32_mdma_filter_fn, &config, ofdma->of_node);
1574 	if (!c) {
1575 		dev_err(mdma2dev(dmadev), "No more channels available\n");
1576 		return NULL;
1577 	}
1578 
1579 	chan = to_stm32_mdma_chan(c);
1580 	chan->chan_config = config;
1581 
1582 	return c;
1583 }
1584 
1585 static const struct of_device_id stm32_mdma_of_match[] = {
1586 	{ .compatible = "st,stm32h7-mdma", },
1587 	{ /* sentinel */ },
1588 };
1589 MODULE_DEVICE_TABLE(of, stm32_mdma_of_match);
1590 
1591 static int stm32_mdma_probe(struct platform_device *pdev)
1592 {
1593 	struct stm32_mdma_chan *chan;
1594 	struct stm32_mdma_device *dmadev;
1595 	struct dma_device *dd;
1596 	struct device_node *of_node;
1597 	struct reset_control *rst;
1598 	u32 nr_channels, nr_requests;
1599 	int i, count, ret;
1600 
1601 	of_node = pdev->dev.of_node;
1602 	if (!of_node)
1603 		return -ENODEV;
1604 
1605 	ret = device_property_read_u32(&pdev->dev, "dma-channels",
1606 				       &nr_channels);
1607 	if (ret) {
1608 		nr_channels = STM32_MDMA_MAX_CHANNELS;
1609 		dev_warn(&pdev->dev, "MDMA defaulting on %i channels\n",
1610 			 nr_channels);
1611 	}
1612 
1613 	ret = device_property_read_u32(&pdev->dev, "dma-requests",
1614 				       &nr_requests);
1615 	if (ret) {
1616 		nr_requests = STM32_MDMA_MAX_REQUESTS;
1617 		dev_warn(&pdev->dev, "MDMA defaulting on %i request lines\n",
1618 			 nr_requests);
1619 	}
1620 
1621 	count = device_property_count_u32(&pdev->dev, "st,ahb-addr-masks");
1622 	if (count < 0)
1623 		count = 0;
1624 
1625 	dmadev = devm_kzalloc(&pdev->dev,
1626 			      struct_size(dmadev, ahb_addr_masks, count),
1627 			      GFP_KERNEL);
1628 	if (!dmadev)
1629 		return -ENOMEM;
1630 
1631 	dmadev->nr_channels = nr_channels;
1632 	dmadev->nr_requests = nr_requests;
1633 	device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks",
1634 				       dmadev->ahb_addr_masks,
1635 				       count);
1636 	dmadev->nr_ahb_addr_masks = count;
1637 
1638 	dmadev->base = devm_platform_ioremap_resource(pdev, 0);
1639 	if (IS_ERR(dmadev->base))
1640 		return PTR_ERR(dmadev->base);
1641 
1642 	dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1643 	if (IS_ERR(dmadev->clk))
1644 		return dev_err_probe(&pdev->dev, PTR_ERR(dmadev->clk),
1645 				     "Missing clock controller\n");
1646 
1647 	ret = clk_prepare_enable(dmadev->clk);
1648 	if (ret < 0) {
1649 		dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
1650 		return ret;
1651 	}
1652 
1653 	rst = devm_reset_control_get(&pdev->dev, NULL);
1654 	if (IS_ERR(rst)) {
1655 		ret = PTR_ERR(rst);
1656 		if (ret == -EPROBE_DEFER)
1657 			goto err_clk;
1658 	} else {
1659 		reset_control_assert(rst);
1660 		udelay(2);
1661 		reset_control_deassert(rst);
1662 	}
1663 
1664 	dd = &dmadev->ddev;
1665 	dma_cap_set(DMA_SLAVE, dd->cap_mask);
1666 	dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1667 	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1668 	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1669 	dd->device_alloc_chan_resources = stm32_mdma_alloc_chan_resources;
1670 	dd->device_free_chan_resources = stm32_mdma_free_chan_resources;
1671 	dd->device_tx_status = stm32_mdma_tx_status;
1672 	dd->device_issue_pending = stm32_mdma_issue_pending;
1673 	dd->device_prep_slave_sg = stm32_mdma_prep_slave_sg;
1674 	dd->device_prep_dma_cyclic = stm32_mdma_prep_dma_cyclic;
1675 	dd->device_prep_dma_memcpy = stm32_mdma_prep_dma_memcpy;
1676 	dd->device_config = stm32_mdma_slave_config;
1677 	dd->device_pause = stm32_mdma_pause;
1678 	dd->device_resume = stm32_mdma_resume;
1679 	dd->device_terminate_all = stm32_mdma_terminate_all;
1680 	dd->device_synchronize = stm32_mdma_synchronize;
1681 	dd->descriptor_reuse = true;
1682 
1683 	dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1684 		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1685 		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1686 		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1687 	dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1688 		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1689 		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1690 		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1691 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1692 		BIT(DMA_MEM_TO_MEM);
1693 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1694 	dd->max_burst = STM32_MDMA_MAX_BURST;
1695 	dd->dev = &pdev->dev;
1696 	INIT_LIST_HEAD(&dd->channels);
1697 
1698 	for (i = 0; i < dmadev->nr_channels; i++) {
1699 		chan = &dmadev->chan[i];
1700 		chan->id = i;
1701 
1702 		if (stm32_mdma_read(dmadev, STM32_MDMA_CCR(i)) & STM32_MDMA_CCR_SM)
1703 			dmadev->chan_reserved |= BIT(i);
1704 
1705 		chan->vchan.desc_free = stm32_mdma_desc_free;
1706 		vchan_init(&chan->vchan, dd);
1707 	}
1708 
1709 	dmadev->irq = platform_get_irq(pdev, 0);
1710 	if (dmadev->irq < 0) {
1711 		ret = dmadev->irq;
1712 		goto err_clk;
1713 	}
1714 
1715 	ret = devm_request_irq(&pdev->dev, dmadev->irq, stm32_mdma_irq_handler,
1716 			       0, dev_name(&pdev->dev), dmadev);
1717 	if (ret) {
1718 		dev_err(&pdev->dev, "failed to request IRQ\n");
1719 		goto err_clk;
1720 	}
1721 
1722 	ret = dmaenginem_async_device_register(dd);
1723 	if (ret)
1724 		goto err_clk;
1725 
1726 	ret = of_dma_controller_register(of_node, stm32_mdma_of_xlate, dmadev);
1727 	if (ret < 0) {
1728 		dev_err(&pdev->dev,
1729 			"STM32 MDMA DMA OF registration failed %d\n", ret);
1730 		goto err_clk;
1731 	}
1732 
1733 	platform_set_drvdata(pdev, dmadev);
1734 	pm_runtime_set_active(&pdev->dev);
1735 	pm_runtime_enable(&pdev->dev);
1736 	pm_runtime_get_noresume(&pdev->dev);
1737 	pm_runtime_put(&pdev->dev);
1738 
1739 	dev_info(&pdev->dev, "STM32 MDMA driver registered\n");
1740 
1741 	return 0;
1742 
1743 err_clk:
1744 	clk_disable_unprepare(dmadev->clk);
1745 
1746 	return ret;
1747 }
1748 
1749 #ifdef CONFIG_PM
1750 static int stm32_mdma_runtime_suspend(struct device *dev)
1751 {
1752 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1753 
1754 	clk_disable_unprepare(dmadev->clk);
1755 
1756 	return 0;
1757 }
1758 
1759 static int stm32_mdma_runtime_resume(struct device *dev)
1760 {
1761 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1762 	int ret;
1763 
1764 	ret = clk_prepare_enable(dmadev->clk);
1765 	if (ret) {
1766 		dev_err(dev, "failed to prepare_enable clock\n");
1767 		return ret;
1768 	}
1769 
1770 	return 0;
1771 }
1772 #endif
1773 
1774 #ifdef CONFIG_PM_SLEEP
1775 static int stm32_mdma_pm_suspend(struct device *dev)
1776 {
1777 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1778 	u32 ccr, id;
1779 	int ret;
1780 
1781 	ret = pm_runtime_resume_and_get(dev);
1782 	if (ret < 0)
1783 		return ret;
1784 
1785 	for (id = 0; id < dmadev->nr_channels; id++) {
1786 		ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
1787 		if (ccr & STM32_MDMA_CCR_EN) {
1788 			dev_warn(dev, "Suspend is prevented by Chan %i\n", id);
1789 			return -EBUSY;
1790 		}
1791 	}
1792 
1793 	pm_runtime_put_sync(dev);
1794 
1795 	pm_runtime_force_suspend(dev);
1796 
1797 	return 0;
1798 }
1799 
1800 static int stm32_mdma_pm_resume(struct device *dev)
1801 {
1802 	return pm_runtime_force_resume(dev);
1803 }
1804 #endif
1805 
1806 static const struct dev_pm_ops stm32_mdma_pm_ops = {
1807 	SET_SYSTEM_SLEEP_PM_OPS(stm32_mdma_pm_suspend, stm32_mdma_pm_resume)
1808 	SET_RUNTIME_PM_OPS(stm32_mdma_runtime_suspend,
1809 			   stm32_mdma_runtime_resume, NULL)
1810 };
1811 
1812 static struct platform_driver stm32_mdma_driver = {
1813 	.probe = stm32_mdma_probe,
1814 	.driver = {
1815 		.name = "stm32-mdma",
1816 		.of_match_table = stm32_mdma_of_match,
1817 		.pm = &stm32_mdma_pm_ops,
1818 	},
1819 };
1820 
1821 static int __init stm32_mdma_init(void)
1822 {
1823 	return platform_driver_register(&stm32_mdma_driver);
1824 }
1825 
1826 subsys_initcall(stm32_mdma_init);
1827 
1828 MODULE_DESCRIPTION("Driver for STM32 MDMA controller");
1829 MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
1830 MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>");
1831