xref: /linux/drivers/dma/stm32/stm32-mdma.c (revision da5b2ad1c2f18834cb1ce429e2e5a5cf5cbdf21b)
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[] __counted_by(count);
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[] __counted_by(nr_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 	desc->count = count;
325 
326 	for (i = 0; i < count; i++) {
327 		desc->node[i].hwdesc =
328 			dma_pool_alloc(chan->desc_pool, GFP_NOWAIT,
329 				       &desc->node[i].hwdesc_phys);
330 		if (!desc->node[i].hwdesc)
331 			goto err;
332 	}
333 
334 	return desc;
335 
336 err:
337 	dev_err(chan2dev(chan), "Failed to allocate descriptor\n");
338 	while (--i >= 0)
339 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
340 			      desc->node[i].hwdesc_phys);
341 	kfree(desc);
342 	return NULL;
343 }
344 
345 static void stm32_mdma_desc_free(struct virt_dma_desc *vdesc)
346 {
347 	struct stm32_mdma_desc *desc = to_stm32_mdma_desc(vdesc);
348 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(vdesc->tx.chan);
349 	int i;
350 
351 	for (i = 0; i < desc->count; i++)
352 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
353 			      desc->node[i].hwdesc_phys);
354 	kfree(desc);
355 }
356 
357 static int stm32_mdma_get_width(struct stm32_mdma_chan *chan,
358 				enum dma_slave_buswidth width)
359 {
360 	switch (width) {
361 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
362 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
363 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
364 	case DMA_SLAVE_BUSWIDTH_8_BYTES:
365 		return ffs(width) - 1;
366 	default:
367 		dev_err(chan2dev(chan), "Dma bus width %i not supported\n",
368 			width);
369 		return -EINVAL;
370 	}
371 }
372 
373 static enum dma_slave_buswidth stm32_mdma_get_max_width(dma_addr_t addr,
374 							u32 buf_len, u32 tlen)
375 {
376 	enum dma_slave_buswidth max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
377 
378 	for (max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
379 	     max_width > DMA_SLAVE_BUSWIDTH_1_BYTE;
380 	     max_width >>= 1) {
381 		/*
382 		 * Address and buffer length both have to be aligned on
383 		 * bus width
384 		 */
385 		if ((((buf_len | addr) & (max_width - 1)) == 0) &&
386 		    tlen >= max_width)
387 			break;
388 	}
389 
390 	return max_width;
391 }
392 
393 static u32 stm32_mdma_get_best_burst(u32 buf_len, u32 tlen, u32 max_burst,
394 				     enum dma_slave_buswidth width)
395 {
396 	u32 best_burst;
397 
398 	best_burst = min((u32)1 << __ffs(tlen | buf_len),
399 			 max_burst * width) / width;
400 
401 	return (best_burst > 0) ? best_burst : 1;
402 }
403 
404 static int stm32_mdma_disable_chan(struct stm32_mdma_chan *chan)
405 {
406 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
407 	u32 ccr, cisr, id, reg;
408 	int ret;
409 
410 	id = chan->id;
411 	reg = STM32_MDMA_CCR(id);
412 
413 	/* Disable interrupts */
414 	stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_IRQ_MASK);
415 
416 	ccr = stm32_mdma_read(dmadev, reg);
417 	if (ccr & STM32_MDMA_CCR_EN) {
418 		stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_EN);
419 
420 		/* Ensure that any ongoing transfer has been completed */
421 		ret = readl_relaxed_poll_timeout_atomic(
422 				dmadev->base + STM32_MDMA_CISR(id), cisr,
423 				(cisr & STM32_MDMA_CISR_CTCIF), 10, 1000);
424 		if (ret) {
425 			dev_err(chan2dev(chan), "%s: timeout!\n", __func__);
426 			return -EBUSY;
427 		}
428 	}
429 
430 	return 0;
431 }
432 
433 static void stm32_mdma_stop(struct stm32_mdma_chan *chan)
434 {
435 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
436 	u32 status;
437 	int ret;
438 
439 	/* Disable DMA */
440 	ret = stm32_mdma_disable_chan(chan);
441 	if (ret < 0)
442 		return;
443 
444 	/* Clear interrupt status if it is there */
445 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
446 	if (status) {
447 		dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
448 			__func__, status);
449 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
450 	}
451 
452 	chan->busy = false;
453 }
454 
455 static void stm32_mdma_set_bus(struct stm32_mdma_device *dmadev, u32 *ctbr,
456 			       u32 ctbr_mask, u32 src_addr)
457 {
458 	u32 mask;
459 	int i;
460 
461 	/* Check if memory device is on AHB or AXI */
462 	*ctbr &= ~ctbr_mask;
463 	mask = src_addr & 0xF0000000;
464 	for (i = 0; i < dmadev->nr_ahb_addr_masks; i++) {
465 		if (mask == dmadev->ahb_addr_masks[i]) {
466 			*ctbr |= ctbr_mask;
467 			break;
468 		}
469 	}
470 }
471 
472 static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
473 				     enum dma_transfer_direction direction,
474 				     u32 *mdma_ccr, u32 *mdma_ctcr,
475 				     u32 *mdma_ctbr, dma_addr_t addr,
476 				     u32 buf_len)
477 {
478 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
479 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
480 	enum dma_slave_buswidth src_addr_width, dst_addr_width;
481 	phys_addr_t src_addr, dst_addr;
482 	int src_bus_width, dst_bus_width;
483 	u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
484 	u32 ccr, ctcr, ctbr, tlen;
485 
486 	src_addr_width = chan->dma_config.src_addr_width;
487 	dst_addr_width = chan->dma_config.dst_addr_width;
488 	src_maxburst = chan->dma_config.src_maxburst;
489 	dst_maxburst = chan->dma_config.dst_maxburst;
490 
491 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & ~STM32_MDMA_CCR_EN;
492 	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
493 	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
494 
495 	/* Enable HW request mode */
496 	ctcr &= ~STM32_MDMA_CTCR_SWRM;
497 
498 	/* Set DINC, SINC, DINCOS, SINCOS, TRGM and TLEN retrieve from DT */
499 	ctcr &= ~STM32_MDMA_CTCR_CFG_MASK;
500 	ctcr |= chan_config->transfer_config & STM32_MDMA_CTCR_CFG_MASK;
501 
502 	/*
503 	 * For buffer transfer length (TLEN) we have to set
504 	 * the number of bytes - 1 in CTCR register
505 	 */
506 	tlen = STM32_MDMA_CTCR_LEN2_GET(ctcr);
507 	ctcr &= ~STM32_MDMA_CTCR_LEN2_MSK;
508 	ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
509 
510 	/* Disable Pack Enable */
511 	ctcr &= ~STM32_MDMA_CTCR_PKE;
512 
513 	/* Check burst size constraints */
514 	if (src_maxburst * src_addr_width > STM32_MDMA_MAX_BURST ||
515 	    dst_maxburst * dst_addr_width > STM32_MDMA_MAX_BURST) {
516 		dev_err(chan2dev(chan),
517 			"burst size * bus width higher than %d bytes\n",
518 			STM32_MDMA_MAX_BURST);
519 		return -EINVAL;
520 	}
521 
522 	if ((!is_power_of_2(src_maxburst) && src_maxburst > 0) ||
523 	    (!is_power_of_2(dst_maxburst) && dst_maxburst > 0)) {
524 		dev_err(chan2dev(chan), "burst size must be a power of 2\n");
525 		return -EINVAL;
526 	}
527 
528 	/*
529 	 * Configure channel control:
530 	 * - Clear SW request as in this case this is a HW one
531 	 * - Clear WEX, HEX and BEX bits
532 	 * - Set priority level
533 	 */
534 	ccr &= ~(STM32_MDMA_CCR_SWRQ | STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
535 		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK);
536 	ccr |= STM32_MDMA_CCR_PL(chan_config->priority_level);
537 
538 	/* Configure Trigger selection */
539 	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
540 	ctbr |= STM32_MDMA_CTBR_TSEL(chan_config->request);
541 
542 	switch (direction) {
543 	case DMA_MEM_TO_DEV:
544 		dst_addr = chan->dma_config.dst_addr;
545 
546 		/* Set device data size */
547 		if (chan_config->m2m_hw)
548 			dst_addr_width = stm32_mdma_get_max_width(dst_addr, buf_len,
549 								  STM32_MDMA_MAX_BUF_LEN);
550 		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
551 		if (dst_bus_width < 0)
552 			return dst_bus_width;
553 		ctcr &= ~STM32_MDMA_CTCR_DSIZE_MASK;
554 		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width);
555 		if (chan_config->m2m_hw) {
556 			ctcr &= ~STM32_MDMA_CTCR_DINCOS_MASK;
557 			ctcr |= STM32_MDMA_CTCR_DINCOS(dst_bus_width);
558 		}
559 
560 		/* Set device burst value */
561 		if (chan_config->m2m_hw)
562 			dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;
563 
564 		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
565 							   dst_maxburst,
566 							   dst_addr_width);
567 		chan->mem_burst = dst_best_burst;
568 		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
569 		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
570 
571 		/* Set memory data size */
572 		src_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
573 		chan->mem_width = src_addr_width;
574 		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
575 		if (src_bus_width < 0)
576 			return src_bus_width;
577 		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK |
578 			STM32_MDMA_CTCR_SINCOS_MASK;
579 		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width) |
580 			STM32_MDMA_CTCR_SINCOS(src_bus_width);
581 
582 		/* Set memory burst value */
583 		src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;
584 		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
585 							   src_maxburst,
586 							   src_addr_width);
587 		chan->mem_burst = src_best_burst;
588 		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
589 		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
590 
591 		/* Select bus */
592 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
593 				   dst_addr);
594 
595 		if (dst_bus_width != src_bus_width)
596 			ctcr |= STM32_MDMA_CTCR_PKE;
597 
598 		/* Set destination address */
599 		stm32_mdma_write(dmadev, STM32_MDMA_CDAR(chan->id), dst_addr);
600 		break;
601 
602 	case DMA_DEV_TO_MEM:
603 		src_addr = chan->dma_config.src_addr;
604 
605 		/* Set device data size */
606 		if (chan_config->m2m_hw)
607 			src_addr_width = stm32_mdma_get_max_width(src_addr, buf_len,
608 								  STM32_MDMA_MAX_BUF_LEN);
609 
610 		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
611 		if (src_bus_width < 0)
612 			return src_bus_width;
613 		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK;
614 		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width);
615 		if (chan_config->m2m_hw) {
616 			ctcr &= ~STM32_MDMA_CTCR_SINCOS_MASK;
617 			ctcr |= STM32_MDMA_CTCR_SINCOS(src_bus_width);
618 		}
619 
620 		/* Set device burst value */
621 		if (chan_config->m2m_hw)
622 			src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;
623 
624 		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
625 							   src_maxburst,
626 							   src_addr_width);
627 		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
628 		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
629 
630 		/* Set memory data size */
631 		dst_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
632 		chan->mem_width = dst_addr_width;
633 		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
634 		if (dst_bus_width < 0)
635 			return dst_bus_width;
636 		ctcr &= ~(STM32_MDMA_CTCR_DSIZE_MASK |
637 			STM32_MDMA_CTCR_DINCOS_MASK);
638 		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
639 			STM32_MDMA_CTCR_DINCOS(dst_bus_width);
640 
641 		/* Set memory burst value */
642 		dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;
643 		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
644 							   dst_maxburst,
645 							   dst_addr_width);
646 		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
647 		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
648 
649 		/* Select bus */
650 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
651 				   src_addr);
652 
653 		if (dst_bus_width != src_bus_width)
654 			ctcr |= STM32_MDMA_CTCR_PKE;
655 
656 		/* Set source address */
657 		stm32_mdma_write(dmadev, STM32_MDMA_CSAR(chan->id), src_addr);
658 		break;
659 
660 	default:
661 		dev_err(chan2dev(chan), "Dma direction is not supported\n");
662 		return -EINVAL;
663 	}
664 
665 	*mdma_ccr = ccr;
666 	*mdma_ctcr = ctcr;
667 	*mdma_ctbr = ctbr;
668 
669 	return 0;
670 }
671 
672 static void stm32_mdma_dump_hwdesc(struct stm32_mdma_chan *chan,
673 				   struct stm32_mdma_desc_node *node)
674 {
675 	dev_dbg(chan2dev(chan), "hwdesc:  %pad\n", &node->hwdesc_phys);
676 	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n", node->hwdesc->ctcr);
677 	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n", node->hwdesc->cbndtr);
678 	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n", node->hwdesc->csar);
679 	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n", node->hwdesc->cdar);
680 	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n", node->hwdesc->cbrur);
681 	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n", node->hwdesc->clar);
682 	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n", node->hwdesc->ctbr);
683 	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n", node->hwdesc->cmar);
684 	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n\n", node->hwdesc->cmdr);
685 }
686 
687 static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
688 				    struct stm32_mdma_desc *desc,
689 				    enum dma_transfer_direction dir, u32 count,
690 				    dma_addr_t src_addr, dma_addr_t dst_addr,
691 				    u32 len, u32 ctcr, u32 ctbr, bool is_last,
692 				    bool is_first, bool is_cyclic)
693 {
694 	struct stm32_mdma_chan_config *config = &chan->chan_config;
695 	struct stm32_mdma_hwdesc *hwdesc;
696 	u32 next = count + 1;
697 
698 	hwdesc = desc->node[count].hwdesc;
699 	hwdesc->ctcr = ctcr;
700 	hwdesc->cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK |
701 			STM32_MDMA_CBNDTR_BRDUM |
702 			STM32_MDMA_CBNDTR_BRSUM |
703 			STM32_MDMA_CBNDTR_BNDT_MASK);
704 	hwdesc->cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
705 	hwdesc->csar = src_addr;
706 	hwdesc->cdar = dst_addr;
707 	hwdesc->cbrur = 0;
708 	hwdesc->ctbr = ctbr;
709 	hwdesc->cmar = config->mask_addr;
710 	hwdesc->cmdr = config->mask_data;
711 
712 	if (is_last) {
713 		if (is_cyclic)
714 			hwdesc->clar = desc->node[0].hwdesc_phys;
715 		else
716 			hwdesc->clar = 0;
717 	} else {
718 		hwdesc->clar = desc->node[next].hwdesc_phys;
719 	}
720 
721 	stm32_mdma_dump_hwdesc(chan, &desc->node[count]);
722 }
723 
724 static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
725 				 struct stm32_mdma_desc *desc,
726 				 struct scatterlist *sgl, u32 sg_len,
727 				 enum dma_transfer_direction direction)
728 {
729 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
730 	struct dma_slave_config *dma_config = &chan->dma_config;
731 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
732 	struct scatterlist *sg;
733 	dma_addr_t src_addr, dst_addr;
734 	u32 m2m_hw_period, ccr, ctcr, ctbr;
735 	int i, ret = 0;
736 
737 	if (chan_config->m2m_hw)
738 		m2m_hw_period = sg_dma_len(sgl);
739 
740 	for_each_sg(sgl, sg, sg_len, i) {
741 		if (sg_dma_len(sg) > STM32_MDMA_MAX_BLOCK_LEN) {
742 			dev_err(chan2dev(chan), "Invalid block len\n");
743 			return -EINVAL;
744 		}
745 
746 		if (direction == DMA_MEM_TO_DEV) {
747 			src_addr = sg_dma_address(sg);
748 			dst_addr = dma_config->dst_addr;
749 			if (chan_config->m2m_hw && (i & 1))
750 				dst_addr += m2m_hw_period;
751 			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
752 							&ctcr, &ctbr, src_addr,
753 							sg_dma_len(sg));
754 			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
755 					   src_addr);
756 		} else {
757 			src_addr = dma_config->src_addr;
758 			if (chan_config->m2m_hw && (i & 1))
759 				src_addr += m2m_hw_period;
760 			dst_addr = sg_dma_address(sg);
761 			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
762 							&ctcr, &ctbr, dst_addr,
763 							sg_dma_len(sg));
764 			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
765 					   dst_addr);
766 		}
767 
768 		if (ret < 0)
769 			return ret;
770 
771 		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
772 					dst_addr, sg_dma_len(sg), ctcr, ctbr,
773 					i == sg_len - 1, i == 0, false);
774 	}
775 
776 	/* Enable interrupts */
777 	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
778 	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE;
779 	desc->ccr = ccr;
780 
781 	return 0;
782 }
783 
784 static struct dma_async_tx_descriptor *
785 stm32_mdma_prep_slave_sg(struct dma_chan *c, struct scatterlist *sgl,
786 			 u32 sg_len, enum dma_transfer_direction direction,
787 			 unsigned long flags, void *context)
788 {
789 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
790 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
791 	struct stm32_mdma_desc *desc;
792 	int i, ret;
793 
794 	/*
795 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
796 	 * channel anymore. The DMA channel needs to be aborted or terminated
797 	 * for allowing another request.
798 	 */
799 	if (chan->desc && chan->desc->cyclic) {
800 		dev_err(chan2dev(chan),
801 			"Request not allowed when dma in cyclic mode\n");
802 		return NULL;
803 	}
804 
805 	desc = stm32_mdma_alloc_desc(chan, sg_len);
806 	if (!desc)
807 		return NULL;
808 
809 	ret = stm32_mdma_setup_xfer(chan, desc, sgl, sg_len, direction);
810 	if (ret < 0)
811 		goto xfer_setup_err;
812 
813 	/*
814 	 * In case of M2M HW transfer triggered by STM32 DMA, we do not have to clear the
815 	 * transfer complete flag by hardware in order to let the CPU rearm the STM32 DMA
816 	 * with the next sg element and update some data in dmaengine framework.
817 	 */
818 	if (chan_config->m2m_hw && direction == DMA_MEM_TO_DEV) {
819 		struct stm32_mdma_hwdesc *hwdesc;
820 
821 		for (i = 0; i < sg_len; i++) {
822 			hwdesc = desc->node[i].hwdesc;
823 			hwdesc->cmar = 0;
824 			hwdesc->cmdr = 0;
825 		}
826 	}
827 
828 	desc->cyclic = false;
829 
830 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
831 
832 xfer_setup_err:
833 	for (i = 0; i < desc->count; i++)
834 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
835 			      desc->node[i].hwdesc_phys);
836 	kfree(desc);
837 	return NULL;
838 }
839 
840 static struct dma_async_tx_descriptor *
841 stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
842 			   size_t buf_len, size_t period_len,
843 			   enum dma_transfer_direction direction,
844 			   unsigned long flags)
845 {
846 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
847 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
848 	struct dma_slave_config *dma_config = &chan->dma_config;
849 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
850 	struct stm32_mdma_desc *desc;
851 	dma_addr_t src_addr, dst_addr;
852 	u32 ccr, ctcr, ctbr, count;
853 	int i, ret;
854 
855 	/*
856 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
857 	 * channel anymore. The DMA channel needs to be aborted or terminated
858 	 * for allowing another request.
859 	 */
860 	if (chan->desc && chan->desc->cyclic) {
861 		dev_err(chan2dev(chan),
862 			"Request not allowed when dma in cyclic mode\n");
863 		return NULL;
864 	}
865 
866 	if (!buf_len || !period_len || period_len > STM32_MDMA_MAX_BLOCK_LEN) {
867 		dev_err(chan2dev(chan), "Invalid buffer/period len\n");
868 		return NULL;
869 	}
870 
871 	if (buf_len % period_len) {
872 		dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
873 		return NULL;
874 	}
875 
876 	count = buf_len / period_len;
877 
878 	desc = stm32_mdma_alloc_desc(chan, count);
879 	if (!desc)
880 		return NULL;
881 
882 	/* Select bus */
883 	if (direction == DMA_MEM_TO_DEV) {
884 		src_addr = buf_addr;
885 		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
886 						&ctbr, src_addr, period_len);
887 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
888 				   src_addr);
889 	} else {
890 		dst_addr = buf_addr;
891 		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
892 						&ctbr, dst_addr, period_len);
893 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
894 				   dst_addr);
895 	}
896 
897 	if (ret < 0)
898 		goto xfer_setup_err;
899 
900 	/* Enable interrupts */
901 	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
902 	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
903 	desc->ccr = ccr;
904 
905 	/* Configure hwdesc list */
906 	for (i = 0; i < count; i++) {
907 		if (direction == DMA_MEM_TO_DEV) {
908 			src_addr = buf_addr + i * period_len;
909 			dst_addr = dma_config->dst_addr;
910 			if (chan_config->m2m_hw && (i & 1))
911 				dst_addr += period_len;
912 		} else {
913 			src_addr = dma_config->src_addr;
914 			if (chan_config->m2m_hw && (i & 1))
915 				src_addr += period_len;
916 			dst_addr = buf_addr + i * period_len;
917 		}
918 
919 		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
920 					dst_addr, period_len, ctcr, ctbr,
921 					i == count - 1, i == 0, true);
922 	}
923 
924 	desc->cyclic = true;
925 
926 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
927 
928 xfer_setup_err:
929 	for (i = 0; i < desc->count; i++)
930 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
931 			      desc->node[i].hwdesc_phys);
932 	kfree(desc);
933 	return NULL;
934 }
935 
936 static struct dma_async_tx_descriptor *
937 stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
938 			   size_t len, unsigned long flags)
939 {
940 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
941 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
942 	enum dma_slave_buswidth max_width;
943 	struct stm32_mdma_desc *desc;
944 	struct stm32_mdma_hwdesc *hwdesc;
945 	u32 ccr, ctcr, ctbr, cbndtr, count, max_burst, mdma_burst;
946 	u32 best_burst, tlen;
947 	size_t xfer_count, offset;
948 	int src_bus_width, dst_bus_width;
949 	int i;
950 
951 	/*
952 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
953 	 * channel anymore. The DMA channel needs to be aborted or terminated
954 	 * to allow another request
955 	 */
956 	if (chan->desc && chan->desc->cyclic) {
957 		dev_err(chan2dev(chan),
958 			"Request not allowed when dma in cyclic mode\n");
959 		return NULL;
960 	}
961 
962 	count = DIV_ROUND_UP(len, STM32_MDMA_MAX_BLOCK_LEN);
963 	desc = stm32_mdma_alloc_desc(chan, count);
964 	if (!desc)
965 		return NULL;
966 
967 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & ~STM32_MDMA_CCR_EN;
968 	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
969 	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
970 	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
971 
972 	/* Enable sw req, some interrupts and clear other bits */
973 	ccr &= ~(STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
974 		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK |
975 		 STM32_MDMA_CCR_IRQ_MASK);
976 	ccr |= STM32_MDMA_CCR_TEIE;
977 
978 	/* Enable SW request mode, dest/src inc and clear other bits */
979 	ctcr &= ~(STM32_MDMA_CTCR_BWM | STM32_MDMA_CTCR_TRGM_MSK |
980 		  STM32_MDMA_CTCR_PAM_MASK | STM32_MDMA_CTCR_PKE |
981 		  STM32_MDMA_CTCR_TLEN_MSK | STM32_MDMA_CTCR_DBURST_MASK |
982 		  STM32_MDMA_CTCR_SBURST_MASK | STM32_MDMA_CTCR_DINCOS_MASK |
983 		  STM32_MDMA_CTCR_SINCOS_MASK | STM32_MDMA_CTCR_DSIZE_MASK |
984 		  STM32_MDMA_CTCR_SSIZE_MASK | STM32_MDMA_CTCR_DINC_MASK |
985 		  STM32_MDMA_CTCR_SINC_MASK);
986 	ctcr |= STM32_MDMA_CTCR_SWRM | STM32_MDMA_CTCR_SINC(STM32_MDMA_INC) |
987 		STM32_MDMA_CTCR_DINC(STM32_MDMA_INC);
988 
989 	/* Reset HW request */
990 	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
991 
992 	/* Select bus */
993 	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS, src);
994 	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS, dest);
995 
996 	/* Clear CBNDTR registers */
997 	cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK | STM32_MDMA_CBNDTR_BRDUM |
998 			STM32_MDMA_CBNDTR_BRSUM | STM32_MDMA_CBNDTR_BNDT_MASK);
999 
1000 	if (len <= STM32_MDMA_MAX_BLOCK_LEN) {
1001 		cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
1002 		if (len <= STM32_MDMA_MAX_BUF_LEN) {
1003 			/* Setup a buffer transfer */
1004 			ccr |= STM32_MDMA_CCR_TCIE | STM32_MDMA_CCR_CTCIE;
1005 			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BUFFER);
1006 		} else {
1007 			/* Setup a block transfer */
1008 			ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
1009 			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BLOCK);
1010 		}
1011 
1012 		tlen = STM32_MDMA_MAX_BUF_LEN;
1013 		ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
1014 
1015 		/* Set source best burst size */
1016 		max_width = stm32_mdma_get_max_width(src, len, tlen);
1017 		src_bus_width = stm32_mdma_get_width(chan, max_width);
1018 
1019 		max_burst = tlen / max_width;
1020 		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
1021 						       max_width);
1022 		mdma_burst = ilog2(best_burst);
1023 
1024 		ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
1025 			STM32_MDMA_CTCR_SSIZE(src_bus_width) |
1026 			STM32_MDMA_CTCR_SINCOS(src_bus_width);
1027 
1028 		/* Set destination best burst size */
1029 		max_width = stm32_mdma_get_max_width(dest, len, tlen);
1030 		dst_bus_width = stm32_mdma_get_width(chan, max_width);
1031 
1032 		max_burst = tlen / max_width;
1033 		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
1034 						       max_width);
1035 		mdma_burst = ilog2(best_burst);
1036 
1037 		ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
1038 			STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
1039 			STM32_MDMA_CTCR_DINCOS(dst_bus_width);
1040 
1041 		if (dst_bus_width != src_bus_width)
1042 			ctcr |= STM32_MDMA_CTCR_PKE;
1043 
1044 		/* Prepare hardware descriptor */
1045 		hwdesc = desc->node[0].hwdesc;
1046 		hwdesc->ctcr = ctcr;
1047 		hwdesc->cbndtr = cbndtr;
1048 		hwdesc->csar = src;
1049 		hwdesc->cdar = dest;
1050 		hwdesc->cbrur = 0;
1051 		hwdesc->clar = 0;
1052 		hwdesc->ctbr = ctbr;
1053 		hwdesc->cmar = 0;
1054 		hwdesc->cmdr = 0;
1055 
1056 		stm32_mdma_dump_hwdesc(chan, &desc->node[0]);
1057 	} else {
1058 		/* Setup a LLI transfer */
1059 		ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_LINKED_LIST) |
1060 			STM32_MDMA_CTCR_TLEN((STM32_MDMA_MAX_BUF_LEN - 1));
1061 		ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
1062 		tlen = STM32_MDMA_MAX_BUF_LEN;
1063 
1064 		for (i = 0, offset = 0; offset < len;
1065 		     i++, offset += xfer_count) {
1066 			xfer_count = min_t(size_t, len - offset,
1067 					   STM32_MDMA_MAX_BLOCK_LEN);
1068 
1069 			/* Set source best burst size */
1070 			max_width = stm32_mdma_get_max_width(src, len, tlen);
1071 			src_bus_width = stm32_mdma_get_width(chan, max_width);
1072 
1073 			max_burst = tlen / max_width;
1074 			best_burst = stm32_mdma_get_best_burst(len, tlen,
1075 							       max_burst,
1076 							       max_width);
1077 			mdma_burst = ilog2(best_burst);
1078 
1079 			ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
1080 				STM32_MDMA_CTCR_SSIZE(src_bus_width) |
1081 				STM32_MDMA_CTCR_SINCOS(src_bus_width);
1082 
1083 			/* Set destination best burst size */
1084 			max_width = stm32_mdma_get_max_width(dest, len, tlen);
1085 			dst_bus_width = stm32_mdma_get_width(chan, max_width);
1086 
1087 			max_burst = tlen / max_width;
1088 			best_burst = stm32_mdma_get_best_burst(len, tlen,
1089 							       max_burst,
1090 							       max_width);
1091 			mdma_burst = ilog2(best_burst);
1092 
1093 			ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
1094 				STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
1095 				STM32_MDMA_CTCR_DINCOS(dst_bus_width);
1096 
1097 			if (dst_bus_width != src_bus_width)
1098 				ctcr |= STM32_MDMA_CTCR_PKE;
1099 
1100 			/* Prepare hardware descriptor */
1101 			stm32_mdma_setup_hwdesc(chan, desc, DMA_MEM_TO_MEM, i,
1102 						src + offset, dest + offset,
1103 						xfer_count, ctcr, ctbr,
1104 						i == count - 1, i == 0, false);
1105 		}
1106 	}
1107 
1108 	desc->ccr = ccr;
1109 
1110 	desc->cyclic = false;
1111 
1112 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1113 }
1114 
1115 static void stm32_mdma_dump_reg(struct stm32_mdma_chan *chan)
1116 {
1117 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1118 
1119 	dev_dbg(chan2dev(chan), "CCR:     0x%08x\n",
1120 		stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)));
1121 	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n",
1122 		stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id)));
1123 	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n",
1124 		stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id)));
1125 	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n",
1126 		stm32_mdma_read(dmadev, STM32_MDMA_CSAR(chan->id)));
1127 	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n",
1128 		stm32_mdma_read(dmadev, STM32_MDMA_CDAR(chan->id)));
1129 	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n",
1130 		stm32_mdma_read(dmadev, STM32_MDMA_CBRUR(chan->id)));
1131 	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n",
1132 		stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id)));
1133 	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n",
1134 		stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id)));
1135 	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n",
1136 		stm32_mdma_read(dmadev, STM32_MDMA_CMAR(chan->id)));
1137 	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n",
1138 		stm32_mdma_read(dmadev, STM32_MDMA_CMDR(chan->id)));
1139 }
1140 
1141 static void stm32_mdma_start_transfer(struct stm32_mdma_chan *chan)
1142 {
1143 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1144 	struct virt_dma_desc *vdesc;
1145 	struct stm32_mdma_hwdesc *hwdesc;
1146 	u32 id = chan->id;
1147 	u32 status, reg;
1148 
1149 	vdesc = vchan_next_desc(&chan->vchan);
1150 	if (!vdesc) {
1151 		chan->desc = NULL;
1152 		return;
1153 	}
1154 
1155 	list_del(&vdesc->node);
1156 
1157 	chan->desc = to_stm32_mdma_desc(vdesc);
1158 	hwdesc = chan->desc->node[0].hwdesc;
1159 	chan->curr_hwdesc = 0;
1160 
1161 	stm32_mdma_write(dmadev, STM32_MDMA_CCR(id), chan->desc->ccr);
1162 	stm32_mdma_write(dmadev, STM32_MDMA_CTCR(id), hwdesc->ctcr);
1163 	stm32_mdma_write(dmadev, STM32_MDMA_CBNDTR(id), hwdesc->cbndtr);
1164 	stm32_mdma_write(dmadev, STM32_MDMA_CSAR(id), hwdesc->csar);
1165 	stm32_mdma_write(dmadev, STM32_MDMA_CDAR(id), hwdesc->cdar);
1166 	stm32_mdma_write(dmadev, STM32_MDMA_CBRUR(id), hwdesc->cbrur);
1167 	stm32_mdma_write(dmadev, STM32_MDMA_CLAR(id), hwdesc->clar);
1168 	stm32_mdma_write(dmadev, STM32_MDMA_CTBR(id), hwdesc->ctbr);
1169 	stm32_mdma_write(dmadev, STM32_MDMA_CMAR(id), hwdesc->cmar);
1170 	stm32_mdma_write(dmadev, STM32_MDMA_CMDR(id), hwdesc->cmdr);
1171 
1172 	/* Clear interrupt status if it is there */
1173 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
1174 	if (status)
1175 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(id), status);
1176 
1177 	stm32_mdma_dump_reg(chan);
1178 
1179 	/* Start DMA */
1180 	stm32_mdma_set_bits(dmadev, STM32_MDMA_CCR(id), STM32_MDMA_CCR_EN);
1181 
1182 	/* Set SW request in case of MEM2MEM transfer */
1183 	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM) {
1184 		reg = STM32_MDMA_CCR(id);
1185 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
1186 	}
1187 
1188 	chan->busy = true;
1189 
1190 	dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
1191 }
1192 
1193 static void stm32_mdma_issue_pending(struct dma_chan *c)
1194 {
1195 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1196 	unsigned long flags;
1197 
1198 	spin_lock_irqsave(&chan->vchan.lock, flags);
1199 
1200 	if (!vchan_issue_pending(&chan->vchan))
1201 		goto end;
1202 
1203 	dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
1204 
1205 	if (!chan->desc && !chan->busy)
1206 		stm32_mdma_start_transfer(chan);
1207 
1208 end:
1209 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1210 }
1211 
1212 static int stm32_mdma_pause(struct dma_chan *c)
1213 {
1214 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1215 	unsigned long flags;
1216 	int ret;
1217 
1218 	spin_lock_irqsave(&chan->vchan.lock, flags);
1219 	ret = stm32_mdma_disable_chan(chan);
1220 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1221 
1222 	if (!ret)
1223 		dev_dbg(chan2dev(chan), "vchan %pK: pause\n", &chan->vchan);
1224 
1225 	return ret;
1226 }
1227 
1228 static int stm32_mdma_resume(struct dma_chan *c)
1229 {
1230 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1231 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1232 	struct stm32_mdma_hwdesc *hwdesc;
1233 	unsigned long flags;
1234 	u32 status, reg;
1235 
1236 	/* Transfer can be terminated */
1237 	if (!chan->desc || (stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)) & STM32_MDMA_CCR_EN))
1238 		return -EPERM;
1239 
1240 	hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc;
1241 
1242 	spin_lock_irqsave(&chan->vchan.lock, flags);
1243 
1244 	/* Re-configure control register */
1245 	stm32_mdma_write(dmadev, STM32_MDMA_CCR(chan->id), chan->desc->ccr);
1246 
1247 	/* Clear interrupt status if it is there */
1248 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
1249 	if (status)
1250 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
1251 
1252 	stm32_mdma_dump_reg(chan);
1253 
1254 	/* Re-start DMA */
1255 	reg = STM32_MDMA_CCR(chan->id);
1256 	stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_EN);
1257 
1258 	/* Set SW request in case of MEM2MEM transfer */
1259 	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM)
1260 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
1261 
1262 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1263 
1264 	dev_dbg(chan2dev(chan), "vchan %pK: resume\n", &chan->vchan);
1265 
1266 	return 0;
1267 }
1268 
1269 static int stm32_mdma_terminate_all(struct dma_chan *c)
1270 {
1271 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1272 	unsigned long flags;
1273 	LIST_HEAD(head);
1274 
1275 	spin_lock_irqsave(&chan->vchan.lock, flags);
1276 	if (chan->desc) {
1277 		vchan_terminate_vdesc(&chan->desc->vdesc);
1278 		if (chan->busy)
1279 			stm32_mdma_stop(chan);
1280 		chan->desc = NULL;
1281 	}
1282 	vchan_get_all_descriptors(&chan->vchan, &head);
1283 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1284 
1285 	vchan_dma_desc_free_list(&chan->vchan, &head);
1286 
1287 	return 0;
1288 }
1289 
1290 static void stm32_mdma_synchronize(struct dma_chan *c)
1291 {
1292 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1293 
1294 	vchan_synchronize(&chan->vchan);
1295 }
1296 
1297 static int stm32_mdma_slave_config(struct dma_chan *c,
1298 				   struct dma_slave_config *config)
1299 {
1300 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1301 
1302 	memcpy(&chan->dma_config, config, sizeof(*config));
1303 
1304 	/* Check if user is requesting STM32 DMA to trigger MDMA */
1305 	if (config->peripheral_size) {
1306 		struct stm32_mdma_dma_config *mdma_config;
1307 
1308 		mdma_config = (struct stm32_mdma_dma_config *)chan->dma_config.peripheral_config;
1309 		chan->chan_config.request = mdma_config->request;
1310 		chan->chan_config.mask_addr = mdma_config->cmar;
1311 		chan->chan_config.mask_data = mdma_config->cmdr;
1312 		chan->chan_config.m2m_hw = true;
1313 	}
1314 
1315 	return 0;
1316 }
1317 
1318 static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
1319 				      struct stm32_mdma_desc *desc,
1320 				      u32 curr_hwdesc,
1321 				      struct dma_tx_state *state)
1322 {
1323 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1324 	struct stm32_mdma_hwdesc *hwdesc;
1325 	u32 cisr, clar, cbndtr, residue, modulo, burst_size;
1326 	int i;
1327 
1328 	cisr = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
1329 
1330 	residue = 0;
1331 	/* Get the next hw descriptor to process from current transfer */
1332 	clar = stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id));
1333 	for (i = desc->count - 1; i >= 0; i--) {
1334 		hwdesc = desc->node[i].hwdesc;
1335 
1336 		if (hwdesc->clar == clar)
1337 			break;/* Current transfer found, stop cumulating */
1338 
1339 		/* Cumulate residue of unprocessed hw descriptors */
1340 		residue += STM32_MDMA_CBNDTR_BNDT(hwdesc->cbndtr);
1341 	}
1342 	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
1343 	residue += cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
1344 
1345 	state->in_flight_bytes = 0;
1346 	if (chan->chan_config.m2m_hw && (cisr & STM32_MDMA_CISR_CRQA))
1347 		state->in_flight_bytes = cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
1348 
1349 	if (!chan->mem_burst)
1350 		return residue;
1351 
1352 	burst_size = chan->mem_burst * chan->mem_width;
1353 	modulo = residue % burst_size;
1354 	if (modulo)
1355 		residue = residue - modulo + burst_size;
1356 
1357 	return residue;
1358 }
1359 
1360 static enum dma_status stm32_mdma_tx_status(struct dma_chan *c,
1361 					    dma_cookie_t cookie,
1362 					    struct dma_tx_state *state)
1363 {
1364 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1365 	struct virt_dma_desc *vdesc;
1366 	enum dma_status status;
1367 	unsigned long flags;
1368 	u32 residue = 0;
1369 
1370 	status = dma_cookie_status(c, cookie, state);
1371 	if ((status == DMA_COMPLETE) || (!state))
1372 		return status;
1373 
1374 	spin_lock_irqsave(&chan->vchan.lock, flags);
1375 
1376 	vdesc = vchan_find_desc(&chan->vchan, cookie);
1377 	if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1378 		residue = stm32_mdma_desc_residue(chan, chan->desc, chan->curr_hwdesc, state);
1379 	else if (vdesc)
1380 		residue = stm32_mdma_desc_residue(chan, to_stm32_mdma_desc(vdesc), 0, state);
1381 
1382 	dma_set_residue(state, residue);
1383 
1384 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1385 
1386 	return status;
1387 }
1388 
1389 static void stm32_mdma_xfer_end(struct stm32_mdma_chan *chan)
1390 {
1391 	vchan_cookie_complete(&chan->desc->vdesc);
1392 	chan->desc = NULL;
1393 	chan->busy = false;
1394 
1395 	/* Start the next transfer if this driver has a next desc */
1396 	stm32_mdma_start_transfer(chan);
1397 }
1398 
1399 static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)
1400 {
1401 	struct stm32_mdma_device *dmadev = devid;
1402 	struct stm32_mdma_chan *chan;
1403 	u32 reg, id, ccr, ien, status;
1404 
1405 	/* Find out which channel generates the interrupt */
1406 	status = readl_relaxed(dmadev->base + STM32_MDMA_GISR0);
1407 	if (!status) {
1408 		dev_dbg(mdma2dev(dmadev), "spurious it\n");
1409 		return IRQ_NONE;
1410 	}
1411 	id = __ffs(status);
1412 	chan = &dmadev->chan[id];
1413 
1414 	/* Handle interrupt for the channel */
1415 	spin_lock(&chan->vchan.lock);
1416 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
1417 	/* Mask Channel ReQuest Active bit which can be set in case of MEM2MEM */
1418 	status &= ~STM32_MDMA_CISR_CRQA;
1419 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
1420 	ien = (ccr & STM32_MDMA_CCR_IRQ_MASK) >> 1;
1421 
1422 	if (!(status & ien)) {
1423 		spin_unlock(&chan->vchan.lock);
1424 		if (chan->busy)
1425 			dev_warn(chan2dev(chan),
1426 				 "spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
1427 		else
1428 			dev_dbg(chan2dev(chan),
1429 				"spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
1430 		return IRQ_NONE;
1431 	}
1432 
1433 	reg = STM32_MDMA_CIFCR(id);
1434 
1435 	if (status & STM32_MDMA_CISR_TEIF) {
1436 		dev_err(chan2dev(chan), "Transfer Err: stat=0x%08x\n",
1437 			readl_relaxed(dmadev->base + STM32_MDMA_CESR(id)));
1438 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CTEIF);
1439 		status &= ~STM32_MDMA_CISR_TEIF;
1440 	}
1441 
1442 	if (status & STM32_MDMA_CISR_CTCIF) {
1443 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CCTCIF);
1444 		status &= ~STM32_MDMA_CISR_CTCIF;
1445 		stm32_mdma_xfer_end(chan);
1446 	}
1447 
1448 	if (status & STM32_MDMA_CISR_BRTIF) {
1449 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBRTIF);
1450 		status &= ~STM32_MDMA_CISR_BRTIF;
1451 	}
1452 
1453 	if (status & STM32_MDMA_CISR_BTIF) {
1454 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBTIF);
1455 		status &= ~STM32_MDMA_CISR_BTIF;
1456 		chan->curr_hwdesc++;
1457 		if (chan->desc && chan->desc->cyclic) {
1458 			if (chan->curr_hwdesc == chan->desc->count)
1459 				chan->curr_hwdesc = 0;
1460 			vchan_cyclic_callback(&chan->desc->vdesc);
1461 		}
1462 	}
1463 
1464 	if (status & STM32_MDMA_CISR_TCIF) {
1465 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CLTCIF);
1466 		status &= ~STM32_MDMA_CISR_TCIF;
1467 	}
1468 
1469 	if (status) {
1470 		stm32_mdma_set_bits(dmadev, reg, status);
1471 		dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
1472 		if (!(ccr & STM32_MDMA_CCR_EN))
1473 			dev_err(chan2dev(chan), "chan disabled by HW\n");
1474 	}
1475 
1476 	spin_unlock(&chan->vchan.lock);
1477 
1478 	return IRQ_HANDLED;
1479 }
1480 
1481 static int stm32_mdma_alloc_chan_resources(struct dma_chan *c)
1482 {
1483 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1484 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1485 	int ret;
1486 
1487 	chan->desc_pool = dmam_pool_create(dev_name(&c->dev->device),
1488 					   c->device->dev,
1489 					   sizeof(struct stm32_mdma_hwdesc),
1490 					  __alignof__(struct stm32_mdma_hwdesc),
1491 					   0);
1492 	if (!chan->desc_pool) {
1493 		dev_err(chan2dev(chan), "failed to allocate descriptor pool\n");
1494 		return -ENOMEM;
1495 	}
1496 
1497 	ret = pm_runtime_resume_and_get(dmadev->ddev.dev);
1498 	if (ret < 0)
1499 		return ret;
1500 
1501 	ret = stm32_mdma_disable_chan(chan);
1502 	if (ret < 0)
1503 		pm_runtime_put(dmadev->ddev.dev);
1504 
1505 	return ret;
1506 }
1507 
1508 static void stm32_mdma_free_chan_resources(struct dma_chan *c)
1509 {
1510 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1511 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1512 	unsigned long flags;
1513 
1514 	dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1515 
1516 	if (chan->busy) {
1517 		spin_lock_irqsave(&chan->vchan.lock, flags);
1518 		stm32_mdma_stop(chan);
1519 		chan->desc = NULL;
1520 		spin_unlock_irqrestore(&chan->vchan.lock, flags);
1521 	}
1522 
1523 	pm_runtime_put(dmadev->ddev.dev);
1524 	vchan_free_chan_resources(to_virt_chan(c));
1525 	dmam_pool_destroy(chan->desc_pool);
1526 	chan->desc_pool = NULL;
1527 }
1528 
1529 static bool stm32_mdma_filter_fn(struct dma_chan *c, void *fn_param)
1530 {
1531 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1532 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1533 
1534 	/* Check if chan is marked Secure */
1535 	if (dmadev->chan_reserved & BIT(chan->id))
1536 		return false;
1537 
1538 	return true;
1539 }
1540 
1541 static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
1542 					    struct of_dma *ofdma)
1543 {
1544 	struct stm32_mdma_device *dmadev = ofdma->of_dma_data;
1545 	dma_cap_mask_t mask = dmadev->ddev.cap_mask;
1546 	struct stm32_mdma_chan *chan;
1547 	struct dma_chan *c;
1548 	struct stm32_mdma_chan_config config;
1549 
1550 	if (dma_spec->args_count < 5) {
1551 		dev_err(mdma2dev(dmadev), "Bad number of args\n");
1552 		return NULL;
1553 	}
1554 
1555 	memset(&config, 0, sizeof(config));
1556 	config.request = dma_spec->args[0];
1557 	config.priority_level = dma_spec->args[1];
1558 	config.transfer_config = dma_spec->args[2];
1559 	config.mask_addr = dma_spec->args[3];
1560 	config.mask_data = dma_spec->args[4];
1561 
1562 	if (config.request >= dmadev->nr_requests) {
1563 		dev_err(mdma2dev(dmadev), "Bad request line\n");
1564 		return NULL;
1565 	}
1566 
1567 	if (config.priority_level > STM32_MDMA_VERY_HIGH_PRIORITY) {
1568 		dev_err(mdma2dev(dmadev), "Priority level not supported\n");
1569 		return NULL;
1570 	}
1571 
1572 	c = __dma_request_channel(&mask, stm32_mdma_filter_fn, &config, ofdma->of_node);
1573 	if (!c) {
1574 		dev_err(mdma2dev(dmadev), "No more channels available\n");
1575 		return NULL;
1576 	}
1577 
1578 	chan = to_stm32_mdma_chan(c);
1579 	chan->chan_config = config;
1580 
1581 	return c;
1582 }
1583 
1584 static const struct of_device_id stm32_mdma_of_match[] = {
1585 	{ .compatible = "st,stm32h7-mdma", },
1586 	{ /* sentinel */ },
1587 };
1588 MODULE_DEVICE_TABLE(of, stm32_mdma_of_match);
1589 
1590 static int stm32_mdma_probe(struct platform_device *pdev)
1591 {
1592 	struct stm32_mdma_chan *chan;
1593 	struct stm32_mdma_device *dmadev;
1594 	struct dma_device *dd;
1595 	struct device_node *of_node;
1596 	struct reset_control *rst;
1597 	u32 nr_channels, nr_requests;
1598 	int i, count, ret;
1599 
1600 	of_node = pdev->dev.of_node;
1601 	if (!of_node)
1602 		return -ENODEV;
1603 
1604 	ret = device_property_read_u32(&pdev->dev, "dma-channels",
1605 				       &nr_channels);
1606 	if (ret) {
1607 		nr_channels = STM32_MDMA_MAX_CHANNELS;
1608 		dev_warn(&pdev->dev, "MDMA defaulting on %i channels\n",
1609 			 nr_channels);
1610 	}
1611 
1612 	ret = device_property_read_u32(&pdev->dev, "dma-requests",
1613 				       &nr_requests);
1614 	if (ret) {
1615 		nr_requests = STM32_MDMA_MAX_REQUESTS;
1616 		dev_warn(&pdev->dev, "MDMA defaulting on %i request lines\n",
1617 			 nr_requests);
1618 	}
1619 
1620 	count = device_property_count_u32(&pdev->dev, "st,ahb-addr-masks");
1621 	if (count < 0)
1622 		count = 0;
1623 
1624 	dmadev = devm_kzalloc(&pdev->dev,
1625 			      struct_size(dmadev, ahb_addr_masks, count),
1626 			      GFP_KERNEL);
1627 	if (!dmadev)
1628 		return -ENOMEM;
1629 	dmadev->nr_ahb_addr_masks = count;
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 
1637 	dmadev->base = devm_platform_ioremap_resource(pdev, 0);
1638 	if (IS_ERR(dmadev->base))
1639 		return PTR_ERR(dmadev->base);
1640 
1641 	dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1642 	if (IS_ERR(dmadev->clk))
1643 		return dev_err_probe(&pdev->dev, PTR_ERR(dmadev->clk),
1644 				     "Missing clock controller\n");
1645 
1646 	ret = clk_prepare_enable(dmadev->clk);
1647 	if (ret < 0) {
1648 		dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
1649 		return ret;
1650 	}
1651 
1652 	rst = devm_reset_control_get(&pdev->dev, NULL);
1653 	if (IS_ERR(rst)) {
1654 		ret = PTR_ERR(rst);
1655 		if (ret == -EPROBE_DEFER)
1656 			goto err_clk;
1657 	} else {
1658 		reset_control_assert(rst);
1659 		udelay(2);
1660 		reset_control_deassert(rst);
1661 	}
1662 
1663 	dd = &dmadev->ddev;
1664 	dma_cap_set(DMA_SLAVE, dd->cap_mask);
1665 	dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1666 	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1667 	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1668 	dd->device_alloc_chan_resources = stm32_mdma_alloc_chan_resources;
1669 	dd->device_free_chan_resources = stm32_mdma_free_chan_resources;
1670 	dd->device_tx_status = stm32_mdma_tx_status;
1671 	dd->device_issue_pending = stm32_mdma_issue_pending;
1672 	dd->device_prep_slave_sg = stm32_mdma_prep_slave_sg;
1673 	dd->device_prep_dma_cyclic = stm32_mdma_prep_dma_cyclic;
1674 	dd->device_prep_dma_memcpy = stm32_mdma_prep_dma_memcpy;
1675 	dd->device_config = stm32_mdma_slave_config;
1676 	dd->device_pause = stm32_mdma_pause;
1677 	dd->device_resume = stm32_mdma_resume;
1678 	dd->device_terminate_all = stm32_mdma_terminate_all;
1679 	dd->device_synchronize = stm32_mdma_synchronize;
1680 	dd->descriptor_reuse = true;
1681 
1682 	dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1683 		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1684 		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1685 		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1686 	dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1687 		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1688 		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1689 		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1690 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1691 		BIT(DMA_MEM_TO_MEM);
1692 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1693 	dd->max_burst = STM32_MDMA_MAX_BURST;
1694 	dd->dev = &pdev->dev;
1695 	INIT_LIST_HEAD(&dd->channels);
1696 
1697 	for (i = 0; i < dmadev->nr_channels; i++) {
1698 		chan = &dmadev->chan[i];
1699 		chan->id = i;
1700 
1701 		if (stm32_mdma_read(dmadev, STM32_MDMA_CCR(i)) & STM32_MDMA_CCR_SM)
1702 			dmadev->chan_reserved |= BIT(i);
1703 
1704 		chan->vchan.desc_free = stm32_mdma_desc_free;
1705 		vchan_init(&chan->vchan, dd);
1706 	}
1707 
1708 	dmadev->irq = platform_get_irq(pdev, 0);
1709 	if (dmadev->irq < 0) {
1710 		ret = dmadev->irq;
1711 		goto err_clk;
1712 	}
1713 
1714 	ret = devm_request_irq(&pdev->dev, dmadev->irq, stm32_mdma_irq_handler,
1715 			       0, dev_name(&pdev->dev), dmadev);
1716 	if (ret) {
1717 		dev_err(&pdev->dev, "failed to request IRQ\n");
1718 		goto err_clk;
1719 	}
1720 
1721 	ret = dmaenginem_async_device_register(dd);
1722 	if (ret)
1723 		goto err_clk;
1724 
1725 	ret = of_dma_controller_register(of_node, stm32_mdma_of_xlate, dmadev);
1726 	if (ret < 0) {
1727 		dev_err(&pdev->dev,
1728 			"STM32 MDMA DMA OF registration failed %d\n", ret);
1729 		goto err_clk;
1730 	}
1731 
1732 	platform_set_drvdata(pdev, dmadev);
1733 	pm_runtime_set_active(&pdev->dev);
1734 	pm_runtime_enable(&pdev->dev);
1735 	pm_runtime_get_noresume(&pdev->dev);
1736 	pm_runtime_put(&pdev->dev);
1737 
1738 	dev_info(&pdev->dev, "STM32 MDMA driver registered\n");
1739 
1740 	return 0;
1741 
1742 err_clk:
1743 	clk_disable_unprepare(dmadev->clk);
1744 
1745 	return ret;
1746 }
1747 
1748 #ifdef CONFIG_PM
1749 static int stm32_mdma_runtime_suspend(struct device *dev)
1750 {
1751 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1752 
1753 	clk_disable_unprepare(dmadev->clk);
1754 
1755 	return 0;
1756 }
1757 
1758 static int stm32_mdma_runtime_resume(struct device *dev)
1759 {
1760 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1761 	int ret;
1762 
1763 	ret = clk_prepare_enable(dmadev->clk);
1764 	if (ret) {
1765 		dev_err(dev, "failed to prepare_enable clock\n");
1766 		return ret;
1767 	}
1768 
1769 	return 0;
1770 }
1771 #endif
1772 
1773 #ifdef CONFIG_PM_SLEEP
1774 static int stm32_mdma_pm_suspend(struct device *dev)
1775 {
1776 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1777 	u32 ccr, id;
1778 	int ret;
1779 
1780 	ret = pm_runtime_resume_and_get(dev);
1781 	if (ret < 0)
1782 		return ret;
1783 
1784 	for (id = 0; id < dmadev->nr_channels; id++) {
1785 		ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
1786 		if (ccr & STM32_MDMA_CCR_EN) {
1787 			dev_warn(dev, "Suspend is prevented by Chan %i\n", id);
1788 			return -EBUSY;
1789 		}
1790 	}
1791 
1792 	pm_runtime_put_sync(dev);
1793 
1794 	pm_runtime_force_suspend(dev);
1795 
1796 	return 0;
1797 }
1798 
1799 static int stm32_mdma_pm_resume(struct device *dev)
1800 {
1801 	return pm_runtime_force_resume(dev);
1802 }
1803 #endif
1804 
1805 static const struct dev_pm_ops stm32_mdma_pm_ops = {
1806 	SET_SYSTEM_SLEEP_PM_OPS(stm32_mdma_pm_suspend, stm32_mdma_pm_resume)
1807 	SET_RUNTIME_PM_OPS(stm32_mdma_runtime_suspend,
1808 			   stm32_mdma_runtime_resume, NULL)
1809 };
1810 
1811 static struct platform_driver stm32_mdma_driver = {
1812 	.probe = stm32_mdma_probe,
1813 	.driver = {
1814 		.name = "stm32-mdma",
1815 		.of_match_table = stm32_mdma_of_match,
1816 		.pm = &stm32_mdma_pm_ops,
1817 	},
1818 };
1819 
1820 static int __init stm32_mdma_init(void)
1821 {
1822 	return platform_driver_register(&stm32_mdma_driver);
1823 }
1824 
1825 subsys_initcall(stm32_mdma_init);
1826 
1827 MODULE_DESCRIPTION("Driver for STM32 MDMA controller");
1828 MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
1829 MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>");
1830