xref: /openbmc/linux/drivers/dma/stm32-mdma.c (revision f71a261a)
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_device.h>
28 #include <linux/of_dma.h>
29 #include <linux/platform_device.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/reset.h>
32 #include <linux/slab.h>
33 
34 #include "virt-dma.h"
35 
36 #define STM32_MDMA_GISR0		0x0000 /* MDMA Int Status Reg 1 */
37 
38 /* MDMA Channel x interrupt/status register */
39 #define STM32_MDMA_CISR(x)		(0x40 + 0x40 * (x)) /* x = 0..62 */
40 #define STM32_MDMA_CISR_CRQA		BIT(16)
41 #define STM32_MDMA_CISR_TCIF		BIT(4)
42 #define STM32_MDMA_CISR_BTIF		BIT(3)
43 #define STM32_MDMA_CISR_BRTIF		BIT(2)
44 #define STM32_MDMA_CISR_CTCIF		BIT(1)
45 #define STM32_MDMA_CISR_TEIF		BIT(0)
46 
47 /* MDMA Channel x interrupt flag clear register */
48 #define STM32_MDMA_CIFCR(x)		(0x44 + 0x40 * (x))
49 #define STM32_MDMA_CIFCR_CLTCIF		BIT(4)
50 #define STM32_MDMA_CIFCR_CBTIF		BIT(3)
51 #define STM32_MDMA_CIFCR_CBRTIF		BIT(2)
52 #define STM32_MDMA_CIFCR_CCTCIF		BIT(1)
53 #define STM32_MDMA_CIFCR_CTEIF		BIT(0)
54 #define STM32_MDMA_CIFCR_CLEAR_ALL	(STM32_MDMA_CIFCR_CLTCIF \
55 					| STM32_MDMA_CIFCR_CBTIF \
56 					| STM32_MDMA_CIFCR_CBRTIF \
57 					| STM32_MDMA_CIFCR_CCTCIF \
58 					| STM32_MDMA_CIFCR_CTEIF)
59 
60 /* MDMA Channel x error status register */
61 #define STM32_MDMA_CESR(x)		(0x48 + 0x40 * (x))
62 #define STM32_MDMA_CESR_BSE		BIT(11)
63 #define STM32_MDMA_CESR_ASR		BIT(10)
64 #define STM32_MDMA_CESR_TEMD		BIT(9)
65 #define STM32_MDMA_CESR_TELD		BIT(8)
66 #define STM32_MDMA_CESR_TED		BIT(7)
67 #define STM32_MDMA_CESR_TEA_MASK	GENMASK(6, 0)
68 
69 /* MDMA Channel x control register */
70 #define STM32_MDMA_CCR(x)		(0x4C + 0x40 * (x))
71 #define STM32_MDMA_CCR_SWRQ		BIT(16)
72 #define STM32_MDMA_CCR_WEX		BIT(14)
73 #define STM32_MDMA_CCR_HEX		BIT(13)
74 #define STM32_MDMA_CCR_BEX		BIT(12)
75 #define STM32_MDMA_CCR_SM		BIT(8)
76 #define STM32_MDMA_CCR_PL_MASK		GENMASK(7, 6)
77 #define STM32_MDMA_CCR_PL(n)		FIELD_PREP(STM32_MDMA_CCR_PL_MASK, (n))
78 #define STM32_MDMA_CCR_TCIE		BIT(5)
79 #define STM32_MDMA_CCR_BTIE		BIT(4)
80 #define STM32_MDMA_CCR_BRTIE		BIT(3)
81 #define STM32_MDMA_CCR_CTCIE		BIT(2)
82 #define STM32_MDMA_CCR_TEIE		BIT(1)
83 #define STM32_MDMA_CCR_EN		BIT(0)
84 #define STM32_MDMA_CCR_IRQ_MASK		(STM32_MDMA_CCR_TCIE \
85 					| STM32_MDMA_CCR_BTIE \
86 					| STM32_MDMA_CCR_BRTIE \
87 					| STM32_MDMA_CCR_CTCIE \
88 					| STM32_MDMA_CCR_TEIE)
89 
90 /* MDMA Channel x transfer configuration register */
91 #define STM32_MDMA_CTCR(x)		(0x50 + 0x40 * (x))
92 #define STM32_MDMA_CTCR_BWM		BIT(31)
93 #define STM32_MDMA_CTCR_SWRM		BIT(30)
94 #define STM32_MDMA_CTCR_TRGM_MSK	GENMASK(29, 28)
95 #define STM32_MDMA_CTCR_TRGM(n)		FIELD_PREP(STM32_MDMA_CTCR_TRGM_MSK, (n))
96 #define STM32_MDMA_CTCR_TRGM_GET(n)	FIELD_GET(STM32_MDMA_CTCR_TRGM_MSK, (n))
97 #define STM32_MDMA_CTCR_PAM_MASK	GENMASK(27, 26)
98 #define STM32_MDMA_CTCR_PAM(n)		FIELD_PREP(STM32_MDMA_CTCR_PAM_MASK, (n))
99 #define STM32_MDMA_CTCR_PKE		BIT(25)
100 #define STM32_MDMA_CTCR_TLEN_MSK	GENMASK(24, 18)
101 #define STM32_MDMA_CTCR_TLEN(n)		FIELD_PREP(STM32_MDMA_CTCR_TLEN_MSK, (n))
102 #define STM32_MDMA_CTCR_TLEN_GET(n)	FIELD_GET(STM32_MDMA_CTCR_TLEN_MSK, (n))
103 #define STM32_MDMA_CTCR_LEN2_MSK	GENMASK(25, 18)
104 #define STM32_MDMA_CTCR_LEN2(n)		FIELD_PREP(STM32_MDMA_CTCR_LEN2_MSK, (n))
105 #define STM32_MDMA_CTCR_LEN2_GET(n)	FIELD_GET(STM32_MDMA_CTCR_LEN2_MSK, (n))
106 #define STM32_MDMA_CTCR_DBURST_MASK	GENMASK(17, 15)
107 #define STM32_MDMA_CTCR_DBURST(n)	FIELD_PREP(STM32_MDMA_CTCR_DBURST_MASK, (n))
108 #define STM32_MDMA_CTCR_SBURST_MASK	GENMASK(14, 12)
109 #define STM32_MDMA_CTCR_SBURST(n)	FIELD_PREP(STM32_MDMA_CTCR_SBURST_MASK, (n))
110 #define STM32_MDMA_CTCR_DINCOS_MASK	GENMASK(11, 10)
111 #define STM32_MDMA_CTCR_DINCOS(n)	FIELD_PREP(STM32_MDMA_CTCR_DINCOS_MASK, (n))
112 #define STM32_MDMA_CTCR_SINCOS_MASK	GENMASK(9, 8)
113 #define STM32_MDMA_CTCR_SINCOS(n)	FIELD_PREP(STM32_MDMA_CTCR_SINCOS_MASK, (n))
114 #define STM32_MDMA_CTCR_DSIZE_MASK	GENMASK(7, 6)
115 #define STM32_MDMA_CTCR_DSIZE(n)	FIELD_PREP(STM32_MDMA_CTCR_DSIZE_MASK, (n))
116 #define STM32_MDMA_CTCR_SSIZE_MASK	GENMASK(5, 4)
117 #define STM32_MDMA_CTCR_SSIZE(n)	FIELD_PREP(STM32_MDMA_CTCR_SSIZE_MASK, (n))
118 #define STM32_MDMA_CTCR_DINC_MASK	GENMASK(3, 2)
119 #define STM32_MDMA_CTCR_DINC(n)		FIELD_PREP(STM32_MDMA_CTCR_DINC_MASK, (n))
120 #define STM32_MDMA_CTCR_SINC_MASK	GENMASK(1, 0)
121 #define STM32_MDMA_CTCR_SINC(n)		FIELD_PREP(STM32_MDMA_CTCR_SINC_MASK, (n))
122 #define STM32_MDMA_CTCR_CFG_MASK	(STM32_MDMA_CTCR_SINC_MASK \
123 					| STM32_MDMA_CTCR_DINC_MASK \
124 					| STM32_MDMA_CTCR_SINCOS_MASK \
125 					| STM32_MDMA_CTCR_DINCOS_MASK \
126 					| STM32_MDMA_CTCR_LEN2_MSK \
127 					| STM32_MDMA_CTCR_TRGM_MSK)
128 
129 /* MDMA Channel x block number of data register */
130 #define STM32_MDMA_CBNDTR(x)		(0x54 + 0x40 * (x))
131 #define STM32_MDMA_CBNDTR_BRC_MK	GENMASK(31, 20)
132 #define STM32_MDMA_CBNDTR_BRC(n)	FIELD_PREP(STM32_MDMA_CBNDTR_BRC_MK, (n))
133 #define STM32_MDMA_CBNDTR_BRC_GET(n)	FIELD_GET(STM32_MDMA_CBNDTR_BRC_MK, (n))
134 
135 #define STM32_MDMA_CBNDTR_BRDUM		BIT(19)
136 #define STM32_MDMA_CBNDTR_BRSUM		BIT(18)
137 #define STM32_MDMA_CBNDTR_BNDT_MASK	GENMASK(16, 0)
138 #define STM32_MDMA_CBNDTR_BNDT(n)	FIELD_PREP(STM32_MDMA_CBNDTR_BNDT_MASK, (n))
139 
140 /* MDMA Channel x source address register */
141 #define STM32_MDMA_CSAR(x)		(0x58 + 0x40 * (x))
142 
143 /* MDMA Channel x destination address register */
144 #define STM32_MDMA_CDAR(x)		(0x5C + 0x40 * (x))
145 
146 /* MDMA Channel x block repeat address update register */
147 #define STM32_MDMA_CBRUR(x)		(0x60 + 0x40 * (x))
148 #define STM32_MDMA_CBRUR_DUV_MASK	GENMASK(31, 16)
149 #define STM32_MDMA_CBRUR_DUV(n)		FIELD_PREP(STM32_MDMA_CBRUR_DUV_MASK, (n))
150 #define STM32_MDMA_CBRUR_SUV_MASK	GENMASK(15, 0)
151 #define STM32_MDMA_CBRUR_SUV(n)		FIELD_PREP(STM32_MDMA_CBRUR_SUV_MASK, (n))
152 
153 /* MDMA Channel x link address register */
154 #define STM32_MDMA_CLAR(x)		(0x64 + 0x40 * (x))
155 
156 /* MDMA Channel x trigger and bus selection register */
157 #define STM32_MDMA_CTBR(x)		(0x68 + 0x40 * (x))
158 #define STM32_MDMA_CTBR_DBUS		BIT(17)
159 #define STM32_MDMA_CTBR_SBUS		BIT(16)
160 #define STM32_MDMA_CTBR_TSEL_MASK	GENMASK(5, 0)
161 #define STM32_MDMA_CTBR_TSEL(n)		FIELD_PREP(STM32_MDMA_CTBR_TSEL_MASK, (n))
162 
163 /* MDMA Channel x mask address register */
164 #define STM32_MDMA_CMAR(x)		(0x70 + 0x40 * (x))
165 
166 /* MDMA Channel x mask data register */
167 #define STM32_MDMA_CMDR(x)		(0x74 + 0x40 * (x))
168 
169 #define STM32_MDMA_MAX_BUF_LEN		128
170 #define STM32_MDMA_MAX_BLOCK_LEN	65536
171 #define STM32_MDMA_MAX_CHANNELS		32
172 #define STM32_MDMA_MAX_REQUESTS		256
173 #define STM32_MDMA_MAX_BURST		128
174 #define STM32_MDMA_VERY_HIGH_PRIORITY	0x3
175 
176 enum stm32_mdma_trigger_mode {
177 	STM32_MDMA_BUFFER,
178 	STM32_MDMA_BLOCK,
179 	STM32_MDMA_BLOCK_REP,
180 	STM32_MDMA_LINKED_LIST,
181 };
182 
183 enum stm32_mdma_width {
184 	STM32_MDMA_BYTE,
185 	STM32_MDMA_HALF_WORD,
186 	STM32_MDMA_WORD,
187 	STM32_MDMA_DOUBLE_WORD,
188 };
189 
190 enum stm32_mdma_inc_mode {
191 	STM32_MDMA_FIXED = 0,
192 	STM32_MDMA_INC = 2,
193 	STM32_MDMA_DEC = 3,
194 };
195 
196 struct stm32_mdma_chan_config {
197 	u32 request;
198 	u32 priority_level;
199 	u32 transfer_config;
200 	u32 mask_addr;
201 	u32 mask_data;
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_chan {
231 	struct virt_dma_chan vchan;
232 	struct dma_pool *desc_pool;
233 	u32 id;
234 	struct stm32_mdma_desc *desc;
235 	u32 curr_hwdesc;
236 	struct dma_slave_config dma_config;
237 	struct stm32_mdma_chan_config chan_config;
238 	bool busy;
239 	u32 mem_burst;
240 	u32 mem_width;
241 };
242 
243 struct stm32_mdma_device {
244 	struct dma_device ddev;
245 	void __iomem *base;
246 	struct clk *clk;
247 	int irq;
248 	u32 nr_channels;
249 	u32 nr_requests;
250 	u32 nr_ahb_addr_masks;
251 	u32 chan_reserved;
252 	struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS];
253 	u32 ahb_addr_masks[];
254 };
255 
256 static struct stm32_mdma_device *stm32_mdma_get_dev(
257 	struct stm32_mdma_chan *chan)
258 {
259 	return container_of(chan->vchan.chan.device, struct stm32_mdma_device,
260 			    ddev);
261 }
262 
263 static struct stm32_mdma_chan *to_stm32_mdma_chan(struct dma_chan *c)
264 {
265 	return container_of(c, struct stm32_mdma_chan, vchan.chan);
266 }
267 
268 static struct stm32_mdma_desc *to_stm32_mdma_desc(struct virt_dma_desc *vdesc)
269 {
270 	return container_of(vdesc, struct stm32_mdma_desc, vdesc);
271 }
272 
273 static struct device *chan2dev(struct stm32_mdma_chan *chan)
274 {
275 	return &chan->vchan.chan.dev->device;
276 }
277 
278 static struct device *mdma2dev(struct stm32_mdma_device *mdma_dev)
279 {
280 	return mdma_dev->ddev.dev;
281 }
282 
283 static u32 stm32_mdma_read(struct stm32_mdma_device *dmadev, u32 reg)
284 {
285 	return readl_relaxed(dmadev->base + reg);
286 }
287 
288 static void stm32_mdma_write(struct stm32_mdma_device *dmadev, u32 reg, u32 val)
289 {
290 	writel_relaxed(val, dmadev->base + reg);
291 }
292 
293 static void stm32_mdma_set_bits(struct stm32_mdma_device *dmadev, u32 reg,
294 				u32 mask)
295 {
296 	void __iomem *addr = dmadev->base + reg;
297 
298 	writel_relaxed(readl_relaxed(addr) | mask, addr);
299 }
300 
301 static void stm32_mdma_clr_bits(struct stm32_mdma_device *dmadev, u32 reg,
302 				u32 mask)
303 {
304 	void __iomem *addr = dmadev->base + reg;
305 
306 	writel_relaxed(readl_relaxed(addr) & ~mask, addr);
307 }
308 
309 static struct stm32_mdma_desc *stm32_mdma_alloc_desc(
310 		struct stm32_mdma_chan *chan, u32 count)
311 {
312 	struct stm32_mdma_desc *desc;
313 	int i;
314 
315 	desc = kzalloc(struct_size(desc, node, count), GFP_NOWAIT);
316 	if (!desc)
317 		return NULL;
318 
319 	for (i = 0; i < count; i++) {
320 		desc->node[i].hwdesc =
321 			dma_pool_alloc(chan->desc_pool, GFP_NOWAIT,
322 				       &desc->node[i].hwdesc_phys);
323 		if (!desc->node[i].hwdesc)
324 			goto err;
325 	}
326 
327 	desc->count = count;
328 
329 	return desc;
330 
331 err:
332 	dev_err(chan2dev(chan), "Failed to allocate descriptor\n");
333 	while (--i >= 0)
334 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
335 			      desc->node[i].hwdesc_phys);
336 	kfree(desc);
337 	return NULL;
338 }
339 
340 static void stm32_mdma_desc_free(struct virt_dma_desc *vdesc)
341 {
342 	struct stm32_mdma_desc *desc = to_stm32_mdma_desc(vdesc);
343 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(vdesc->tx.chan);
344 	int i;
345 
346 	for (i = 0; i < desc->count; i++)
347 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
348 			      desc->node[i].hwdesc_phys);
349 	kfree(desc);
350 }
351 
352 static int stm32_mdma_get_width(struct stm32_mdma_chan *chan,
353 				enum dma_slave_buswidth width)
354 {
355 	switch (width) {
356 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
357 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
358 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
359 	case DMA_SLAVE_BUSWIDTH_8_BYTES:
360 		return ffs(width) - 1;
361 	default:
362 		dev_err(chan2dev(chan), "Dma bus width %i not supported\n",
363 			width);
364 		return -EINVAL;
365 	}
366 }
367 
368 static enum dma_slave_buswidth stm32_mdma_get_max_width(dma_addr_t addr,
369 							u32 buf_len, u32 tlen)
370 {
371 	enum dma_slave_buswidth max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
372 
373 	for (max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
374 	     max_width > DMA_SLAVE_BUSWIDTH_1_BYTE;
375 	     max_width >>= 1) {
376 		/*
377 		 * Address and buffer length both have to be aligned on
378 		 * bus width
379 		 */
380 		if ((((buf_len | addr) & (max_width - 1)) == 0) &&
381 		    tlen >= max_width)
382 			break;
383 	}
384 
385 	return max_width;
386 }
387 
388 static u32 stm32_mdma_get_best_burst(u32 buf_len, u32 tlen, u32 max_burst,
389 				     enum dma_slave_buswidth width)
390 {
391 	u32 best_burst;
392 
393 	best_burst = min((u32)1 << __ffs(tlen | buf_len),
394 			 max_burst * width) / width;
395 
396 	return (best_burst > 0) ? best_burst : 1;
397 }
398 
399 static int stm32_mdma_disable_chan(struct stm32_mdma_chan *chan)
400 {
401 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
402 	u32 ccr, cisr, id, reg;
403 	int ret;
404 
405 	id = chan->id;
406 	reg = STM32_MDMA_CCR(id);
407 
408 	/* Disable interrupts */
409 	stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_IRQ_MASK);
410 
411 	ccr = stm32_mdma_read(dmadev, reg);
412 	if (ccr & STM32_MDMA_CCR_EN) {
413 		stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_EN);
414 
415 		/* Ensure that any ongoing transfer has been completed */
416 		ret = readl_relaxed_poll_timeout_atomic(
417 				dmadev->base + STM32_MDMA_CISR(id), cisr,
418 				(cisr & STM32_MDMA_CISR_CTCIF), 10, 1000);
419 		if (ret) {
420 			dev_err(chan2dev(chan), "%s: timeout!\n", __func__);
421 			return -EBUSY;
422 		}
423 	}
424 
425 	return 0;
426 }
427 
428 static void stm32_mdma_stop(struct stm32_mdma_chan *chan)
429 {
430 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
431 	u32 status;
432 	int ret;
433 
434 	/* Disable DMA */
435 	ret = stm32_mdma_disable_chan(chan);
436 	if (ret < 0)
437 		return;
438 
439 	/* Clear interrupt status if it is there */
440 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
441 	if (status) {
442 		dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
443 			__func__, status);
444 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
445 	}
446 
447 	chan->busy = false;
448 }
449 
450 static void stm32_mdma_set_bus(struct stm32_mdma_device *dmadev, u32 *ctbr,
451 			       u32 ctbr_mask, u32 src_addr)
452 {
453 	u32 mask;
454 	int i;
455 
456 	/* Check if memory device is on AHB or AXI */
457 	*ctbr &= ~ctbr_mask;
458 	mask = src_addr & 0xF0000000;
459 	for (i = 0; i < dmadev->nr_ahb_addr_masks; i++) {
460 		if (mask == dmadev->ahb_addr_masks[i]) {
461 			*ctbr |= ctbr_mask;
462 			break;
463 		}
464 	}
465 }
466 
467 static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
468 				     enum dma_transfer_direction direction,
469 				     u32 *mdma_ccr, u32 *mdma_ctcr,
470 				     u32 *mdma_ctbr, dma_addr_t addr,
471 				     u32 buf_len)
472 {
473 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
474 	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
475 	enum dma_slave_buswidth src_addr_width, dst_addr_width;
476 	phys_addr_t src_addr, dst_addr;
477 	int src_bus_width, dst_bus_width;
478 	u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
479 	u32 ccr, ctcr, ctbr, tlen;
480 
481 	src_addr_width = chan->dma_config.src_addr_width;
482 	dst_addr_width = chan->dma_config.dst_addr_width;
483 	src_maxburst = chan->dma_config.src_maxburst;
484 	dst_maxburst = chan->dma_config.dst_maxburst;
485 
486 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
487 	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
488 	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
489 
490 	/* Enable HW request mode */
491 	ctcr &= ~STM32_MDMA_CTCR_SWRM;
492 
493 	/* Set DINC, SINC, DINCOS, SINCOS, TRGM and TLEN retrieve from DT */
494 	ctcr &= ~STM32_MDMA_CTCR_CFG_MASK;
495 	ctcr |= chan_config->transfer_config & STM32_MDMA_CTCR_CFG_MASK;
496 
497 	/*
498 	 * For buffer transfer length (TLEN) we have to set
499 	 * the number of bytes - 1 in CTCR register
500 	 */
501 	tlen = STM32_MDMA_CTCR_LEN2_GET(ctcr);
502 	ctcr &= ~STM32_MDMA_CTCR_LEN2_MSK;
503 	ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
504 
505 	/* Disable Pack Enable */
506 	ctcr &= ~STM32_MDMA_CTCR_PKE;
507 
508 	/* Check burst size constraints */
509 	if (src_maxburst * src_addr_width > STM32_MDMA_MAX_BURST ||
510 	    dst_maxburst * dst_addr_width > STM32_MDMA_MAX_BURST) {
511 		dev_err(chan2dev(chan),
512 			"burst size * bus width higher than %d bytes\n",
513 			STM32_MDMA_MAX_BURST);
514 		return -EINVAL;
515 	}
516 
517 	if ((!is_power_of_2(src_maxburst) && src_maxburst > 0) ||
518 	    (!is_power_of_2(dst_maxburst) && dst_maxburst > 0)) {
519 		dev_err(chan2dev(chan), "burst size must be a power of 2\n");
520 		return -EINVAL;
521 	}
522 
523 	/*
524 	 * Configure channel control:
525 	 * - Clear SW request as in this case this is a HW one
526 	 * - Clear WEX, HEX and BEX bits
527 	 * - Set priority level
528 	 */
529 	ccr &= ~(STM32_MDMA_CCR_SWRQ | STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
530 		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK);
531 	ccr |= STM32_MDMA_CCR_PL(chan_config->priority_level);
532 
533 	/* Configure Trigger selection */
534 	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
535 	ctbr |= STM32_MDMA_CTBR_TSEL(chan_config->request);
536 
537 	switch (direction) {
538 	case DMA_MEM_TO_DEV:
539 		dst_addr = chan->dma_config.dst_addr;
540 
541 		/* Set device data size */
542 		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
543 		if (dst_bus_width < 0)
544 			return dst_bus_width;
545 		ctcr &= ~STM32_MDMA_CTCR_DSIZE_MASK;
546 		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width);
547 
548 		/* Set device burst value */
549 		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
550 							   dst_maxburst,
551 							   dst_addr_width);
552 		chan->mem_burst = dst_best_burst;
553 		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
554 		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
555 
556 		/* Set memory data size */
557 		src_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
558 		chan->mem_width = src_addr_width;
559 		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
560 		if (src_bus_width < 0)
561 			return src_bus_width;
562 		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK |
563 			STM32_MDMA_CTCR_SINCOS_MASK;
564 		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width) |
565 			STM32_MDMA_CTCR_SINCOS(src_bus_width);
566 
567 		/* Set memory burst value */
568 		src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;
569 		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
570 							   src_maxburst,
571 							   src_addr_width);
572 		chan->mem_burst = src_best_burst;
573 		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
574 		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
575 
576 		/* Select bus */
577 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
578 				   dst_addr);
579 
580 		if (dst_bus_width != src_bus_width)
581 			ctcr |= STM32_MDMA_CTCR_PKE;
582 
583 		/* Set destination address */
584 		stm32_mdma_write(dmadev, STM32_MDMA_CDAR(chan->id), dst_addr);
585 		break;
586 
587 	case DMA_DEV_TO_MEM:
588 		src_addr = chan->dma_config.src_addr;
589 
590 		/* Set device data size */
591 		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
592 		if (src_bus_width < 0)
593 			return src_bus_width;
594 		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK;
595 		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width);
596 
597 		/* Set device burst value */
598 		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
599 							   src_maxburst,
600 							   src_addr_width);
601 		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
602 		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
603 
604 		/* Set memory data size */
605 		dst_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
606 		chan->mem_width = dst_addr_width;
607 		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
608 		if (dst_bus_width < 0)
609 			return dst_bus_width;
610 		ctcr &= ~(STM32_MDMA_CTCR_DSIZE_MASK |
611 			STM32_MDMA_CTCR_DINCOS_MASK);
612 		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
613 			STM32_MDMA_CTCR_DINCOS(dst_bus_width);
614 
615 		/* Set memory burst value */
616 		dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;
617 		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
618 							   dst_maxburst,
619 							   dst_addr_width);
620 		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
621 		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
622 
623 		/* Select bus */
624 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
625 				   src_addr);
626 
627 		if (dst_bus_width != src_bus_width)
628 			ctcr |= STM32_MDMA_CTCR_PKE;
629 
630 		/* Set source address */
631 		stm32_mdma_write(dmadev, STM32_MDMA_CSAR(chan->id), src_addr);
632 		break;
633 
634 	default:
635 		dev_err(chan2dev(chan), "Dma direction is not supported\n");
636 		return -EINVAL;
637 	}
638 
639 	*mdma_ccr = ccr;
640 	*mdma_ctcr = ctcr;
641 	*mdma_ctbr = ctbr;
642 
643 	return 0;
644 }
645 
646 static void stm32_mdma_dump_hwdesc(struct stm32_mdma_chan *chan,
647 				   struct stm32_mdma_desc_node *node)
648 {
649 	dev_dbg(chan2dev(chan), "hwdesc:  %pad\n", &node->hwdesc_phys);
650 	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n", node->hwdesc->ctcr);
651 	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n", node->hwdesc->cbndtr);
652 	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n", node->hwdesc->csar);
653 	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n", node->hwdesc->cdar);
654 	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n", node->hwdesc->cbrur);
655 	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n", node->hwdesc->clar);
656 	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n", node->hwdesc->ctbr);
657 	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n", node->hwdesc->cmar);
658 	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n\n", node->hwdesc->cmdr);
659 }
660 
661 static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
662 				    struct stm32_mdma_desc *desc,
663 				    enum dma_transfer_direction dir, u32 count,
664 				    dma_addr_t src_addr, dma_addr_t dst_addr,
665 				    u32 len, u32 ctcr, u32 ctbr, bool is_last,
666 				    bool is_first, bool is_cyclic)
667 {
668 	struct stm32_mdma_chan_config *config = &chan->chan_config;
669 	struct stm32_mdma_hwdesc *hwdesc;
670 	u32 next = count + 1;
671 
672 	hwdesc = desc->node[count].hwdesc;
673 	hwdesc->ctcr = ctcr;
674 	hwdesc->cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK |
675 			STM32_MDMA_CBNDTR_BRDUM |
676 			STM32_MDMA_CBNDTR_BRSUM |
677 			STM32_MDMA_CBNDTR_BNDT_MASK);
678 	hwdesc->cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
679 	hwdesc->csar = src_addr;
680 	hwdesc->cdar = dst_addr;
681 	hwdesc->cbrur = 0;
682 	hwdesc->ctbr = ctbr;
683 	hwdesc->cmar = config->mask_addr;
684 	hwdesc->cmdr = config->mask_data;
685 
686 	if (is_last) {
687 		if (is_cyclic)
688 			hwdesc->clar = desc->node[0].hwdesc_phys;
689 		else
690 			hwdesc->clar = 0;
691 	} else {
692 		hwdesc->clar = desc->node[next].hwdesc_phys;
693 	}
694 
695 	stm32_mdma_dump_hwdesc(chan, &desc->node[count]);
696 }
697 
698 static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
699 				 struct stm32_mdma_desc *desc,
700 				 struct scatterlist *sgl, u32 sg_len,
701 				 enum dma_transfer_direction direction)
702 {
703 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
704 	struct dma_slave_config *dma_config = &chan->dma_config;
705 	struct scatterlist *sg;
706 	dma_addr_t src_addr, dst_addr;
707 	u32 ccr, ctcr, ctbr;
708 	int i, ret = 0;
709 
710 	for_each_sg(sgl, sg, sg_len, i) {
711 		if (sg_dma_len(sg) > STM32_MDMA_MAX_BLOCK_LEN) {
712 			dev_err(chan2dev(chan), "Invalid block len\n");
713 			return -EINVAL;
714 		}
715 
716 		if (direction == DMA_MEM_TO_DEV) {
717 			src_addr = sg_dma_address(sg);
718 			dst_addr = dma_config->dst_addr;
719 			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
720 							&ctcr, &ctbr, src_addr,
721 							sg_dma_len(sg));
722 			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
723 					   src_addr);
724 		} else {
725 			src_addr = dma_config->src_addr;
726 			dst_addr = sg_dma_address(sg);
727 			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
728 							&ctcr, &ctbr, dst_addr,
729 							sg_dma_len(sg));
730 			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
731 					   dst_addr);
732 		}
733 
734 		if (ret < 0)
735 			return ret;
736 
737 		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
738 					dst_addr, sg_dma_len(sg), ctcr, ctbr,
739 					i == sg_len - 1, i == 0, false);
740 	}
741 
742 	/* Enable interrupts */
743 	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
744 	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE;
745 	if (sg_len > 1)
746 		ccr |= STM32_MDMA_CCR_BTIE;
747 	desc->ccr = ccr;
748 
749 	return 0;
750 }
751 
752 static struct dma_async_tx_descriptor *
753 stm32_mdma_prep_slave_sg(struct dma_chan *c, struct scatterlist *sgl,
754 			 u32 sg_len, enum dma_transfer_direction direction,
755 			 unsigned long flags, void *context)
756 {
757 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
758 	struct stm32_mdma_desc *desc;
759 	int i, ret;
760 
761 	/*
762 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
763 	 * channel anymore. The DMA channel needs to be aborted or terminated
764 	 * for allowing another request.
765 	 */
766 	if (chan->desc && chan->desc->cyclic) {
767 		dev_err(chan2dev(chan),
768 			"Request not allowed when dma in cyclic mode\n");
769 		return NULL;
770 	}
771 
772 	desc = stm32_mdma_alloc_desc(chan, sg_len);
773 	if (!desc)
774 		return NULL;
775 
776 	ret = stm32_mdma_setup_xfer(chan, desc, sgl, sg_len, direction);
777 	if (ret < 0)
778 		goto xfer_setup_err;
779 
780 	desc->cyclic = false;
781 
782 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
783 
784 xfer_setup_err:
785 	for (i = 0; i < desc->count; i++)
786 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
787 			      desc->node[i].hwdesc_phys);
788 	kfree(desc);
789 	return NULL;
790 }
791 
792 static struct dma_async_tx_descriptor *
793 stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
794 			   size_t buf_len, size_t period_len,
795 			   enum dma_transfer_direction direction,
796 			   unsigned long flags)
797 {
798 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
799 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
800 	struct dma_slave_config *dma_config = &chan->dma_config;
801 	struct stm32_mdma_desc *desc;
802 	dma_addr_t src_addr, dst_addr;
803 	u32 ccr, ctcr, ctbr, count;
804 	int i, ret;
805 
806 	/*
807 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
808 	 * channel anymore. The DMA channel needs to be aborted or terminated
809 	 * for allowing another request.
810 	 */
811 	if (chan->desc && chan->desc->cyclic) {
812 		dev_err(chan2dev(chan),
813 			"Request not allowed when dma in cyclic mode\n");
814 		return NULL;
815 	}
816 
817 	if (!buf_len || !period_len || period_len > STM32_MDMA_MAX_BLOCK_LEN) {
818 		dev_err(chan2dev(chan), "Invalid buffer/period len\n");
819 		return NULL;
820 	}
821 
822 	if (buf_len % period_len) {
823 		dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
824 		return NULL;
825 	}
826 
827 	count = buf_len / period_len;
828 
829 	desc = stm32_mdma_alloc_desc(chan, count);
830 	if (!desc)
831 		return NULL;
832 
833 	/* Select bus */
834 	if (direction == DMA_MEM_TO_DEV) {
835 		src_addr = buf_addr;
836 		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
837 						&ctbr, src_addr, period_len);
838 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
839 				   src_addr);
840 	} else {
841 		dst_addr = buf_addr;
842 		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
843 						&ctbr, dst_addr, period_len);
844 		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
845 				   dst_addr);
846 	}
847 
848 	if (ret < 0)
849 		goto xfer_setup_err;
850 
851 	/* Enable interrupts */
852 	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
853 	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
854 	desc->ccr = ccr;
855 
856 	/* Configure hwdesc list */
857 	for (i = 0; i < count; i++) {
858 		if (direction == DMA_MEM_TO_DEV) {
859 			src_addr = buf_addr + i * period_len;
860 			dst_addr = dma_config->dst_addr;
861 		} else {
862 			src_addr = dma_config->src_addr;
863 			dst_addr = buf_addr + i * period_len;
864 		}
865 
866 		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
867 					dst_addr, period_len, ctcr, ctbr,
868 					i == count - 1, i == 0, true);
869 	}
870 
871 	desc->cyclic = true;
872 
873 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
874 
875 xfer_setup_err:
876 	for (i = 0; i < desc->count; i++)
877 		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
878 			      desc->node[i].hwdesc_phys);
879 	kfree(desc);
880 	return NULL;
881 }
882 
883 static struct dma_async_tx_descriptor *
884 stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
885 			   size_t len, unsigned long flags)
886 {
887 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
888 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
889 	enum dma_slave_buswidth max_width;
890 	struct stm32_mdma_desc *desc;
891 	struct stm32_mdma_hwdesc *hwdesc;
892 	u32 ccr, ctcr, ctbr, cbndtr, count, max_burst, mdma_burst;
893 	u32 best_burst, tlen;
894 	size_t xfer_count, offset;
895 	int src_bus_width, dst_bus_width;
896 	int i;
897 
898 	/*
899 	 * Once DMA is in setup cyclic mode the channel we cannot assign this
900 	 * channel anymore. The DMA channel needs to be aborted or terminated
901 	 * to allow another request
902 	 */
903 	if (chan->desc && chan->desc->cyclic) {
904 		dev_err(chan2dev(chan),
905 			"Request not allowed when dma in cyclic mode\n");
906 		return NULL;
907 	}
908 
909 	count = DIV_ROUND_UP(len, STM32_MDMA_MAX_BLOCK_LEN);
910 	desc = stm32_mdma_alloc_desc(chan, count);
911 	if (!desc)
912 		return NULL;
913 
914 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
915 	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
916 	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
917 	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
918 
919 	/* Enable sw req, some interrupts and clear other bits */
920 	ccr &= ~(STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
921 		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK |
922 		 STM32_MDMA_CCR_IRQ_MASK);
923 	ccr |= STM32_MDMA_CCR_TEIE;
924 
925 	/* Enable SW request mode, dest/src inc and clear other bits */
926 	ctcr &= ~(STM32_MDMA_CTCR_BWM | STM32_MDMA_CTCR_TRGM_MSK |
927 		  STM32_MDMA_CTCR_PAM_MASK | STM32_MDMA_CTCR_PKE |
928 		  STM32_MDMA_CTCR_TLEN_MSK | STM32_MDMA_CTCR_DBURST_MASK |
929 		  STM32_MDMA_CTCR_SBURST_MASK | STM32_MDMA_CTCR_DINCOS_MASK |
930 		  STM32_MDMA_CTCR_SINCOS_MASK | STM32_MDMA_CTCR_DSIZE_MASK |
931 		  STM32_MDMA_CTCR_SSIZE_MASK | STM32_MDMA_CTCR_DINC_MASK |
932 		  STM32_MDMA_CTCR_SINC_MASK);
933 	ctcr |= STM32_MDMA_CTCR_SWRM | STM32_MDMA_CTCR_SINC(STM32_MDMA_INC) |
934 		STM32_MDMA_CTCR_DINC(STM32_MDMA_INC);
935 
936 	/* Reset HW request */
937 	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
938 
939 	/* Select bus */
940 	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS, src);
941 	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS, dest);
942 
943 	/* Clear CBNDTR registers */
944 	cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK | STM32_MDMA_CBNDTR_BRDUM |
945 			STM32_MDMA_CBNDTR_BRSUM | STM32_MDMA_CBNDTR_BNDT_MASK);
946 
947 	if (len <= STM32_MDMA_MAX_BLOCK_LEN) {
948 		cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
949 		if (len <= STM32_MDMA_MAX_BUF_LEN) {
950 			/* Setup a buffer transfer */
951 			ccr |= STM32_MDMA_CCR_TCIE | STM32_MDMA_CCR_CTCIE;
952 			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BUFFER);
953 		} else {
954 			/* Setup a block transfer */
955 			ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
956 			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BLOCK);
957 		}
958 
959 		tlen = STM32_MDMA_MAX_BUF_LEN;
960 		ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
961 
962 		/* Set source best burst size */
963 		max_width = stm32_mdma_get_max_width(src, len, tlen);
964 		src_bus_width = stm32_mdma_get_width(chan, max_width);
965 
966 		max_burst = tlen / max_width;
967 		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
968 						       max_width);
969 		mdma_burst = ilog2(best_burst);
970 
971 		ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
972 			STM32_MDMA_CTCR_SSIZE(src_bus_width) |
973 			STM32_MDMA_CTCR_SINCOS(src_bus_width);
974 
975 		/* Set destination best burst size */
976 		max_width = stm32_mdma_get_max_width(dest, len, tlen);
977 		dst_bus_width = stm32_mdma_get_width(chan, max_width);
978 
979 		max_burst = tlen / max_width;
980 		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
981 						       max_width);
982 		mdma_burst = ilog2(best_burst);
983 
984 		ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
985 			STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
986 			STM32_MDMA_CTCR_DINCOS(dst_bus_width);
987 
988 		if (dst_bus_width != src_bus_width)
989 			ctcr |= STM32_MDMA_CTCR_PKE;
990 
991 		/* Prepare hardware descriptor */
992 		hwdesc = desc->node[0].hwdesc;
993 		hwdesc->ctcr = ctcr;
994 		hwdesc->cbndtr = cbndtr;
995 		hwdesc->csar = src;
996 		hwdesc->cdar = dest;
997 		hwdesc->cbrur = 0;
998 		hwdesc->clar = 0;
999 		hwdesc->ctbr = ctbr;
1000 		hwdesc->cmar = 0;
1001 		hwdesc->cmdr = 0;
1002 
1003 		stm32_mdma_dump_hwdesc(chan, &desc->node[0]);
1004 	} else {
1005 		/* Setup a LLI transfer */
1006 		ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_LINKED_LIST) |
1007 			STM32_MDMA_CTCR_TLEN((STM32_MDMA_MAX_BUF_LEN - 1));
1008 		ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
1009 		tlen = STM32_MDMA_MAX_BUF_LEN;
1010 
1011 		for (i = 0, offset = 0; offset < len;
1012 		     i++, offset += xfer_count) {
1013 			xfer_count = min_t(size_t, len - offset,
1014 					   STM32_MDMA_MAX_BLOCK_LEN);
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,
1022 							       max_burst,
1023 							       max_width);
1024 			mdma_burst = ilog2(best_burst);
1025 
1026 			ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
1027 				STM32_MDMA_CTCR_SSIZE(src_bus_width) |
1028 				STM32_MDMA_CTCR_SINCOS(src_bus_width);
1029 
1030 			/* Set destination best burst size */
1031 			max_width = stm32_mdma_get_max_width(dest, len, tlen);
1032 			dst_bus_width = stm32_mdma_get_width(chan, max_width);
1033 
1034 			max_burst = tlen / max_width;
1035 			best_burst = stm32_mdma_get_best_burst(len, tlen,
1036 							       max_burst,
1037 							       max_width);
1038 			mdma_burst = ilog2(best_burst);
1039 
1040 			ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
1041 				STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
1042 				STM32_MDMA_CTCR_DINCOS(dst_bus_width);
1043 
1044 			if (dst_bus_width != src_bus_width)
1045 				ctcr |= STM32_MDMA_CTCR_PKE;
1046 
1047 			/* Prepare hardware descriptor */
1048 			stm32_mdma_setup_hwdesc(chan, desc, DMA_MEM_TO_MEM, i,
1049 						src + offset, dest + offset,
1050 						xfer_count, ctcr, ctbr,
1051 						i == count - 1, i == 0, false);
1052 		}
1053 	}
1054 
1055 	desc->ccr = ccr;
1056 
1057 	desc->cyclic = false;
1058 
1059 	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1060 }
1061 
1062 static void stm32_mdma_dump_reg(struct stm32_mdma_chan *chan)
1063 {
1064 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1065 
1066 	dev_dbg(chan2dev(chan), "CCR:     0x%08x\n",
1067 		stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)));
1068 	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n",
1069 		stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id)));
1070 	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n",
1071 		stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id)));
1072 	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n",
1073 		stm32_mdma_read(dmadev, STM32_MDMA_CSAR(chan->id)));
1074 	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n",
1075 		stm32_mdma_read(dmadev, STM32_MDMA_CDAR(chan->id)));
1076 	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n",
1077 		stm32_mdma_read(dmadev, STM32_MDMA_CBRUR(chan->id)));
1078 	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n",
1079 		stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id)));
1080 	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n",
1081 		stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id)));
1082 	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n",
1083 		stm32_mdma_read(dmadev, STM32_MDMA_CMAR(chan->id)));
1084 	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n",
1085 		stm32_mdma_read(dmadev, STM32_MDMA_CMDR(chan->id)));
1086 }
1087 
1088 static void stm32_mdma_start_transfer(struct stm32_mdma_chan *chan)
1089 {
1090 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1091 	struct virt_dma_desc *vdesc;
1092 	struct stm32_mdma_hwdesc *hwdesc;
1093 	u32 id = chan->id;
1094 	u32 status, reg;
1095 
1096 	vdesc = vchan_next_desc(&chan->vchan);
1097 	if (!vdesc) {
1098 		chan->desc = NULL;
1099 		return;
1100 	}
1101 
1102 	list_del(&vdesc->node);
1103 
1104 	chan->desc = to_stm32_mdma_desc(vdesc);
1105 	hwdesc = chan->desc->node[0].hwdesc;
1106 	chan->curr_hwdesc = 0;
1107 
1108 	stm32_mdma_write(dmadev, STM32_MDMA_CCR(id), chan->desc->ccr);
1109 	stm32_mdma_write(dmadev, STM32_MDMA_CTCR(id), hwdesc->ctcr);
1110 	stm32_mdma_write(dmadev, STM32_MDMA_CBNDTR(id), hwdesc->cbndtr);
1111 	stm32_mdma_write(dmadev, STM32_MDMA_CSAR(id), hwdesc->csar);
1112 	stm32_mdma_write(dmadev, STM32_MDMA_CDAR(id), hwdesc->cdar);
1113 	stm32_mdma_write(dmadev, STM32_MDMA_CBRUR(id), hwdesc->cbrur);
1114 	stm32_mdma_write(dmadev, STM32_MDMA_CLAR(id), hwdesc->clar);
1115 	stm32_mdma_write(dmadev, STM32_MDMA_CTBR(id), hwdesc->ctbr);
1116 	stm32_mdma_write(dmadev, STM32_MDMA_CMAR(id), hwdesc->cmar);
1117 	stm32_mdma_write(dmadev, STM32_MDMA_CMDR(id), hwdesc->cmdr);
1118 
1119 	/* Clear interrupt status if it is there */
1120 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
1121 	if (status)
1122 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(id), status);
1123 
1124 	stm32_mdma_dump_reg(chan);
1125 
1126 	/* Start DMA */
1127 	stm32_mdma_set_bits(dmadev, STM32_MDMA_CCR(id), STM32_MDMA_CCR_EN);
1128 
1129 	/* Set SW request in case of MEM2MEM transfer */
1130 	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM) {
1131 		reg = STM32_MDMA_CCR(id);
1132 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
1133 	}
1134 
1135 	chan->busy = true;
1136 
1137 	dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
1138 }
1139 
1140 static void stm32_mdma_issue_pending(struct dma_chan *c)
1141 {
1142 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1143 	unsigned long flags;
1144 
1145 	spin_lock_irqsave(&chan->vchan.lock, flags);
1146 
1147 	if (!vchan_issue_pending(&chan->vchan))
1148 		goto end;
1149 
1150 	dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
1151 
1152 	if (!chan->desc && !chan->busy)
1153 		stm32_mdma_start_transfer(chan);
1154 
1155 end:
1156 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1157 }
1158 
1159 static int stm32_mdma_pause(struct dma_chan *c)
1160 {
1161 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1162 	unsigned long flags;
1163 	int ret;
1164 
1165 	spin_lock_irqsave(&chan->vchan.lock, flags);
1166 	ret = stm32_mdma_disable_chan(chan);
1167 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1168 
1169 	if (!ret)
1170 		dev_dbg(chan2dev(chan), "vchan %pK: pause\n", &chan->vchan);
1171 
1172 	return ret;
1173 }
1174 
1175 static int stm32_mdma_resume(struct dma_chan *c)
1176 {
1177 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1178 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1179 	struct stm32_mdma_hwdesc *hwdesc;
1180 	unsigned long flags;
1181 	u32 status, reg;
1182 
1183 	hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc;
1184 
1185 	spin_lock_irqsave(&chan->vchan.lock, flags);
1186 
1187 	/* Re-configure control register */
1188 	stm32_mdma_write(dmadev, STM32_MDMA_CCR(chan->id), chan->desc->ccr);
1189 
1190 	/* Clear interrupt status if it is there */
1191 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
1192 	if (status)
1193 		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
1194 
1195 	stm32_mdma_dump_reg(chan);
1196 
1197 	/* Re-start DMA */
1198 	reg = STM32_MDMA_CCR(chan->id);
1199 	stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_EN);
1200 
1201 	/* Set SW request in case of MEM2MEM transfer */
1202 	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM)
1203 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
1204 
1205 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1206 
1207 	dev_dbg(chan2dev(chan), "vchan %pK: resume\n", &chan->vchan);
1208 
1209 	return 0;
1210 }
1211 
1212 static int stm32_mdma_terminate_all(struct dma_chan *c)
1213 {
1214 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1215 	unsigned long flags;
1216 	LIST_HEAD(head);
1217 
1218 	spin_lock_irqsave(&chan->vchan.lock, flags);
1219 	if (chan->desc) {
1220 		vchan_terminate_vdesc(&chan->desc->vdesc);
1221 		if (chan->busy)
1222 			stm32_mdma_stop(chan);
1223 		chan->desc = NULL;
1224 	}
1225 	vchan_get_all_descriptors(&chan->vchan, &head);
1226 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1227 
1228 	vchan_dma_desc_free_list(&chan->vchan, &head);
1229 
1230 	return 0;
1231 }
1232 
1233 static void stm32_mdma_synchronize(struct dma_chan *c)
1234 {
1235 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1236 
1237 	vchan_synchronize(&chan->vchan);
1238 }
1239 
1240 static int stm32_mdma_slave_config(struct dma_chan *c,
1241 				   struct dma_slave_config *config)
1242 {
1243 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1244 
1245 	memcpy(&chan->dma_config, config, sizeof(*config));
1246 
1247 	return 0;
1248 }
1249 
1250 static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
1251 				      struct stm32_mdma_desc *desc,
1252 				      u32 curr_hwdesc)
1253 {
1254 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1255 	struct stm32_mdma_hwdesc *hwdesc;
1256 	u32 cbndtr, residue, modulo, burst_size;
1257 	int i;
1258 
1259 	residue = 0;
1260 	for (i = curr_hwdesc + 1; i < desc->count; i++) {
1261 		hwdesc = desc->node[i].hwdesc;
1262 		residue += STM32_MDMA_CBNDTR_BNDT(hwdesc->cbndtr);
1263 	}
1264 	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
1265 	residue += cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
1266 
1267 	if (!chan->mem_burst)
1268 		return residue;
1269 
1270 	burst_size = chan->mem_burst * chan->mem_width;
1271 	modulo = residue % burst_size;
1272 	if (modulo)
1273 		residue = residue - modulo + burst_size;
1274 
1275 	return residue;
1276 }
1277 
1278 static enum dma_status stm32_mdma_tx_status(struct dma_chan *c,
1279 					    dma_cookie_t cookie,
1280 					    struct dma_tx_state *state)
1281 {
1282 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1283 	struct virt_dma_desc *vdesc;
1284 	enum dma_status status;
1285 	unsigned long flags;
1286 	u32 residue = 0;
1287 
1288 	status = dma_cookie_status(c, cookie, state);
1289 	if ((status == DMA_COMPLETE) || (!state))
1290 		return status;
1291 
1292 	spin_lock_irqsave(&chan->vchan.lock, flags);
1293 
1294 	vdesc = vchan_find_desc(&chan->vchan, cookie);
1295 	if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1296 		residue = stm32_mdma_desc_residue(chan, chan->desc,
1297 						  chan->curr_hwdesc);
1298 	else if (vdesc)
1299 		residue = stm32_mdma_desc_residue(chan,
1300 						  to_stm32_mdma_desc(vdesc), 0);
1301 	dma_set_residue(state, residue);
1302 
1303 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1304 
1305 	return status;
1306 }
1307 
1308 static void stm32_mdma_xfer_end(struct stm32_mdma_chan *chan)
1309 {
1310 	vchan_cookie_complete(&chan->desc->vdesc);
1311 	chan->desc = NULL;
1312 	chan->busy = false;
1313 
1314 	/* Start the next transfer if this driver has a next desc */
1315 	stm32_mdma_start_transfer(chan);
1316 }
1317 
1318 static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)
1319 {
1320 	struct stm32_mdma_device *dmadev = devid;
1321 	struct stm32_mdma_chan *chan;
1322 	u32 reg, id, ccr, ien, status;
1323 
1324 	/* Find out which channel generates the interrupt */
1325 	status = readl_relaxed(dmadev->base + STM32_MDMA_GISR0);
1326 	if (!status) {
1327 		dev_dbg(mdma2dev(dmadev), "spurious it\n");
1328 		return IRQ_NONE;
1329 	}
1330 	id = __ffs(status);
1331 
1332 	chan = &dmadev->chan[id];
1333 	if (!chan) {
1334 		dev_warn(mdma2dev(dmadev), "MDMA channel not initialized\n");
1335 		return IRQ_NONE;
1336 	}
1337 
1338 	/* Handle interrupt for the channel */
1339 	spin_lock(&chan->vchan.lock);
1340 	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
1341 	/* Mask Channel ReQuest Active bit which can be set in case of MEM2MEM */
1342 	status &= ~STM32_MDMA_CISR_CRQA;
1343 	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
1344 	ien = (ccr & STM32_MDMA_CCR_IRQ_MASK) >> 1;
1345 
1346 	if (!(status & ien)) {
1347 		spin_unlock(&chan->vchan.lock);
1348 		if (chan->busy)
1349 			dev_warn(chan2dev(chan),
1350 				 "spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
1351 		else
1352 			dev_dbg(chan2dev(chan),
1353 				"spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
1354 		return IRQ_NONE;
1355 	}
1356 
1357 	reg = STM32_MDMA_CIFCR(id);
1358 
1359 	if (status & STM32_MDMA_CISR_TEIF) {
1360 		dev_err(chan2dev(chan), "Transfer Err: stat=0x%08x\n",
1361 			readl_relaxed(dmadev->base + STM32_MDMA_CESR(id)));
1362 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CTEIF);
1363 		status &= ~STM32_MDMA_CISR_TEIF;
1364 	}
1365 
1366 	if (status & STM32_MDMA_CISR_CTCIF) {
1367 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CCTCIF);
1368 		status &= ~STM32_MDMA_CISR_CTCIF;
1369 		stm32_mdma_xfer_end(chan);
1370 	}
1371 
1372 	if (status & STM32_MDMA_CISR_BRTIF) {
1373 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBRTIF);
1374 		status &= ~STM32_MDMA_CISR_BRTIF;
1375 	}
1376 
1377 	if (status & STM32_MDMA_CISR_BTIF) {
1378 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBTIF);
1379 		status &= ~STM32_MDMA_CISR_BTIF;
1380 		chan->curr_hwdesc++;
1381 		if (chan->desc && chan->desc->cyclic) {
1382 			if (chan->curr_hwdesc == chan->desc->count)
1383 				chan->curr_hwdesc = 0;
1384 			vchan_cyclic_callback(&chan->desc->vdesc);
1385 		}
1386 	}
1387 
1388 	if (status & STM32_MDMA_CISR_TCIF) {
1389 		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CLTCIF);
1390 		status &= ~STM32_MDMA_CISR_TCIF;
1391 	}
1392 
1393 	if (status) {
1394 		stm32_mdma_set_bits(dmadev, reg, status);
1395 		dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
1396 		if (!(ccr & STM32_MDMA_CCR_EN))
1397 			dev_err(chan2dev(chan), "chan disabled by HW\n");
1398 	}
1399 
1400 	spin_unlock(&chan->vchan.lock);
1401 
1402 	return IRQ_HANDLED;
1403 }
1404 
1405 static int stm32_mdma_alloc_chan_resources(struct dma_chan *c)
1406 {
1407 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1408 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1409 	int ret;
1410 
1411 	chan->desc_pool = dmam_pool_create(dev_name(&c->dev->device),
1412 					   c->device->dev,
1413 					   sizeof(struct stm32_mdma_hwdesc),
1414 					  __alignof__(struct stm32_mdma_hwdesc),
1415 					   0);
1416 	if (!chan->desc_pool) {
1417 		dev_err(chan2dev(chan), "failed to allocate descriptor pool\n");
1418 		return -ENOMEM;
1419 	}
1420 
1421 	ret = pm_runtime_resume_and_get(dmadev->ddev.dev);
1422 	if (ret < 0)
1423 		return ret;
1424 
1425 	ret = stm32_mdma_disable_chan(chan);
1426 	if (ret < 0)
1427 		pm_runtime_put(dmadev->ddev.dev);
1428 
1429 	return ret;
1430 }
1431 
1432 static void stm32_mdma_free_chan_resources(struct dma_chan *c)
1433 {
1434 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1435 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1436 	unsigned long flags;
1437 
1438 	dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1439 
1440 	if (chan->busy) {
1441 		spin_lock_irqsave(&chan->vchan.lock, flags);
1442 		stm32_mdma_stop(chan);
1443 		chan->desc = NULL;
1444 		spin_unlock_irqrestore(&chan->vchan.lock, flags);
1445 	}
1446 
1447 	pm_runtime_put(dmadev->ddev.dev);
1448 	vchan_free_chan_resources(to_virt_chan(c));
1449 	dmam_pool_destroy(chan->desc_pool);
1450 	chan->desc_pool = NULL;
1451 }
1452 
1453 static bool stm32_mdma_filter_fn(struct dma_chan *c, void *fn_param)
1454 {
1455 	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
1456 	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
1457 
1458 	/* Check if chan is marked Secure */
1459 	if (dmadev->chan_reserved & BIT(chan->id))
1460 		return false;
1461 
1462 	return true;
1463 }
1464 
1465 static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
1466 					    struct of_dma *ofdma)
1467 {
1468 	struct stm32_mdma_device *dmadev = ofdma->of_dma_data;
1469 	dma_cap_mask_t mask = dmadev->ddev.cap_mask;
1470 	struct stm32_mdma_chan *chan;
1471 	struct dma_chan *c;
1472 	struct stm32_mdma_chan_config config;
1473 
1474 	if (dma_spec->args_count < 5) {
1475 		dev_err(mdma2dev(dmadev), "Bad number of args\n");
1476 		return NULL;
1477 	}
1478 
1479 	config.request = dma_spec->args[0];
1480 	config.priority_level = dma_spec->args[1];
1481 	config.transfer_config = dma_spec->args[2];
1482 	config.mask_addr = dma_spec->args[3];
1483 	config.mask_data = dma_spec->args[4];
1484 
1485 	if (config.request >= dmadev->nr_requests) {
1486 		dev_err(mdma2dev(dmadev), "Bad request line\n");
1487 		return NULL;
1488 	}
1489 
1490 	if (config.priority_level > STM32_MDMA_VERY_HIGH_PRIORITY) {
1491 		dev_err(mdma2dev(dmadev), "Priority level not supported\n");
1492 		return NULL;
1493 	}
1494 
1495 	c = __dma_request_channel(&mask, stm32_mdma_filter_fn, &config, ofdma->of_node);
1496 	if (!c) {
1497 		dev_err(mdma2dev(dmadev), "No more channels available\n");
1498 		return NULL;
1499 	}
1500 
1501 	chan = to_stm32_mdma_chan(c);
1502 	chan->chan_config = config;
1503 
1504 	return c;
1505 }
1506 
1507 static const struct of_device_id stm32_mdma_of_match[] = {
1508 	{ .compatible = "st,stm32h7-mdma", },
1509 	{ /* sentinel */ },
1510 };
1511 MODULE_DEVICE_TABLE(of, stm32_mdma_of_match);
1512 
1513 static int stm32_mdma_probe(struct platform_device *pdev)
1514 {
1515 	struct stm32_mdma_chan *chan;
1516 	struct stm32_mdma_device *dmadev;
1517 	struct dma_device *dd;
1518 	struct device_node *of_node;
1519 	struct resource *res;
1520 	struct reset_control *rst;
1521 	u32 nr_channels, nr_requests;
1522 	int i, count, ret;
1523 
1524 	of_node = pdev->dev.of_node;
1525 	if (!of_node)
1526 		return -ENODEV;
1527 
1528 	ret = device_property_read_u32(&pdev->dev, "dma-channels",
1529 				       &nr_channels);
1530 	if (ret) {
1531 		nr_channels = STM32_MDMA_MAX_CHANNELS;
1532 		dev_warn(&pdev->dev, "MDMA defaulting on %i channels\n",
1533 			 nr_channels);
1534 	}
1535 
1536 	ret = device_property_read_u32(&pdev->dev, "dma-requests",
1537 				       &nr_requests);
1538 	if (ret) {
1539 		nr_requests = STM32_MDMA_MAX_REQUESTS;
1540 		dev_warn(&pdev->dev, "MDMA defaulting on %i request lines\n",
1541 			 nr_requests);
1542 	}
1543 
1544 	count = device_property_count_u32(&pdev->dev, "st,ahb-addr-masks");
1545 	if (count < 0)
1546 		count = 0;
1547 
1548 	dmadev = devm_kzalloc(&pdev->dev,
1549 			      struct_size(dmadev, ahb_addr_masks, count),
1550 			      GFP_KERNEL);
1551 	if (!dmadev)
1552 		return -ENOMEM;
1553 
1554 	dmadev->nr_channels = nr_channels;
1555 	dmadev->nr_requests = nr_requests;
1556 	device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks",
1557 				       dmadev->ahb_addr_masks,
1558 				       count);
1559 	dmadev->nr_ahb_addr_masks = count;
1560 
1561 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1562 	dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1563 	if (IS_ERR(dmadev->base))
1564 		return PTR_ERR(dmadev->base);
1565 
1566 	dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1567 	if (IS_ERR(dmadev->clk))
1568 		return dev_err_probe(&pdev->dev, PTR_ERR(dmadev->clk),
1569 				     "Missing clock controller\n");
1570 
1571 	ret = clk_prepare_enable(dmadev->clk);
1572 	if (ret < 0) {
1573 		dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
1574 		return ret;
1575 	}
1576 
1577 	rst = devm_reset_control_get(&pdev->dev, NULL);
1578 	if (IS_ERR(rst)) {
1579 		ret = PTR_ERR(rst);
1580 		if (ret == -EPROBE_DEFER)
1581 			goto err_clk;
1582 	} else {
1583 		reset_control_assert(rst);
1584 		udelay(2);
1585 		reset_control_deassert(rst);
1586 	}
1587 
1588 	dd = &dmadev->ddev;
1589 	dma_cap_set(DMA_SLAVE, dd->cap_mask);
1590 	dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1591 	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1592 	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1593 	dd->device_alloc_chan_resources = stm32_mdma_alloc_chan_resources;
1594 	dd->device_free_chan_resources = stm32_mdma_free_chan_resources;
1595 	dd->device_tx_status = stm32_mdma_tx_status;
1596 	dd->device_issue_pending = stm32_mdma_issue_pending;
1597 	dd->device_prep_slave_sg = stm32_mdma_prep_slave_sg;
1598 	dd->device_prep_dma_cyclic = stm32_mdma_prep_dma_cyclic;
1599 	dd->device_prep_dma_memcpy = stm32_mdma_prep_dma_memcpy;
1600 	dd->device_config = stm32_mdma_slave_config;
1601 	dd->device_pause = stm32_mdma_pause;
1602 	dd->device_resume = stm32_mdma_resume;
1603 	dd->device_terminate_all = stm32_mdma_terminate_all;
1604 	dd->device_synchronize = stm32_mdma_synchronize;
1605 	dd->descriptor_reuse = true;
1606 
1607 	dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1608 		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1609 		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1610 		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1611 	dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1612 		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1613 		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1614 		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1615 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
1616 		BIT(DMA_MEM_TO_MEM);
1617 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1618 	dd->max_burst = STM32_MDMA_MAX_BURST;
1619 	dd->dev = &pdev->dev;
1620 	INIT_LIST_HEAD(&dd->channels);
1621 
1622 	for (i = 0; i < dmadev->nr_channels; i++) {
1623 		chan = &dmadev->chan[i];
1624 		chan->id = i;
1625 
1626 		if (stm32_mdma_read(dmadev, STM32_MDMA_CCR(i)) & STM32_MDMA_CCR_SM)
1627 			dmadev->chan_reserved |= BIT(i);
1628 
1629 		chan->vchan.desc_free = stm32_mdma_desc_free;
1630 		vchan_init(&chan->vchan, dd);
1631 	}
1632 
1633 	dmadev->irq = platform_get_irq(pdev, 0);
1634 	if (dmadev->irq < 0) {
1635 		ret = dmadev->irq;
1636 		goto err_clk;
1637 	}
1638 
1639 	ret = devm_request_irq(&pdev->dev, dmadev->irq, stm32_mdma_irq_handler,
1640 			       0, dev_name(&pdev->dev), dmadev);
1641 	if (ret) {
1642 		dev_err(&pdev->dev, "failed to request IRQ\n");
1643 		goto err_clk;
1644 	}
1645 
1646 	ret = dmaenginem_async_device_register(dd);
1647 	if (ret)
1648 		goto err_clk;
1649 
1650 	ret = of_dma_controller_register(of_node, stm32_mdma_of_xlate, dmadev);
1651 	if (ret < 0) {
1652 		dev_err(&pdev->dev,
1653 			"STM32 MDMA DMA OF registration failed %d\n", ret);
1654 		goto err_clk;
1655 	}
1656 
1657 	platform_set_drvdata(pdev, dmadev);
1658 	pm_runtime_set_active(&pdev->dev);
1659 	pm_runtime_enable(&pdev->dev);
1660 	pm_runtime_get_noresume(&pdev->dev);
1661 	pm_runtime_put(&pdev->dev);
1662 
1663 	dev_info(&pdev->dev, "STM32 MDMA driver registered\n");
1664 
1665 	return 0;
1666 
1667 err_clk:
1668 	clk_disable_unprepare(dmadev->clk);
1669 
1670 	return ret;
1671 }
1672 
1673 #ifdef CONFIG_PM
1674 static int stm32_mdma_runtime_suspend(struct device *dev)
1675 {
1676 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1677 
1678 	clk_disable_unprepare(dmadev->clk);
1679 
1680 	return 0;
1681 }
1682 
1683 static int stm32_mdma_runtime_resume(struct device *dev)
1684 {
1685 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1686 	int ret;
1687 
1688 	ret = clk_prepare_enable(dmadev->clk);
1689 	if (ret) {
1690 		dev_err(dev, "failed to prepare_enable clock\n");
1691 		return ret;
1692 	}
1693 
1694 	return 0;
1695 }
1696 #endif
1697 
1698 #ifdef CONFIG_PM_SLEEP
1699 static int stm32_mdma_pm_suspend(struct device *dev)
1700 {
1701 	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
1702 	u32 ccr, id;
1703 	int ret;
1704 
1705 	ret = pm_runtime_resume_and_get(dev);
1706 	if (ret < 0)
1707 		return ret;
1708 
1709 	for (id = 0; id < dmadev->nr_channels; id++) {
1710 		ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
1711 		if (ccr & STM32_MDMA_CCR_EN) {
1712 			dev_warn(dev, "Suspend is prevented by Chan %i\n", id);
1713 			return -EBUSY;
1714 		}
1715 	}
1716 
1717 	pm_runtime_put_sync(dev);
1718 
1719 	pm_runtime_force_suspend(dev);
1720 
1721 	return 0;
1722 }
1723 
1724 static int stm32_mdma_pm_resume(struct device *dev)
1725 {
1726 	return pm_runtime_force_resume(dev);
1727 }
1728 #endif
1729 
1730 static const struct dev_pm_ops stm32_mdma_pm_ops = {
1731 	SET_SYSTEM_SLEEP_PM_OPS(stm32_mdma_pm_suspend, stm32_mdma_pm_resume)
1732 	SET_RUNTIME_PM_OPS(stm32_mdma_runtime_suspend,
1733 			   stm32_mdma_runtime_resume, NULL)
1734 };
1735 
1736 static struct platform_driver stm32_mdma_driver = {
1737 	.probe = stm32_mdma_probe,
1738 	.driver = {
1739 		.name = "stm32-mdma",
1740 		.of_match_table = stm32_mdma_of_match,
1741 		.pm = &stm32_mdma_pm_ops,
1742 	},
1743 };
1744 
1745 static int __init stm32_mdma_init(void)
1746 {
1747 	return platform_driver_register(&stm32_mdma_driver);
1748 }
1749 
1750 subsys_initcall(stm32_mdma_init);
1751 
1752 MODULE_DESCRIPTION("Driver for STM32 MDMA controller");
1753 MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
1754 MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>");
1755 MODULE_LICENSE("GPL v2");
1756