xref: /linux/drivers/dma/stm32/stm32-dma3.c (revision 1fd1dc41724319406b0aff221a352a400b0ddfc5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * STM32 DMA3 controller driver
4  *
5  * Copyright (C) STMicroelectronics 2024
6  * Author(s): Amelie Delaunay <amelie.delaunay@foss.st.com>
7  */
8 
9 #include <linux/bitfield.h>
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmaengine.h>
13 #include <linux/dmapool.h>
14 #include <linux/init.h>
15 #include <linux/iopoll.h>
16 #include <linux/list.h>
17 #include <linux/module.h>
18 #include <linux/of_dma.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/reset.h>
22 #include <linux/slab.h>
23 
24 #include "../virt-dma.h"
25 
26 #define STM32_DMA3_SECCFGR		0x00
27 #define STM32_DMA3_PRIVCFGR		0x04
28 #define STM32_DMA3_RCFGLOCKR		0x08
29 #define STM32_DMA3_MISR			0x0c
30 #define STM32_DMA3_SMISR		0x10
31 
32 #define STM32_DMA3_CLBAR(x)		(0x50 + 0x80 * (x))
33 #define STM32_DMA3_CCIDCFGR(x)		(0x54 + 0x80 * (x))
34 #define STM32_DMA3_CSEMCR(x)		(0x58 + 0x80 * (x))
35 #define STM32_DMA3_CFCR(x)		(0x5c + 0x80 * (x))
36 #define STM32_DMA3_CSR(x)		(0x60 + 0x80 * (x))
37 #define STM32_DMA3_CCR(x)		(0x64 + 0x80 * (x))
38 #define STM32_DMA3_CTR1(x)		(0x90 + 0x80 * (x))
39 #define STM32_DMA3_CTR2(x)		(0x94 + 0x80 * (x))
40 #define STM32_DMA3_CBR1(x)		(0x98 + 0x80 * (x))
41 #define STM32_DMA3_CSAR(x)		(0x9c + 0x80 * (x))
42 #define STM32_DMA3_CDAR(x)		(0xa0 + 0x80 * (x))
43 #define STM32_DMA3_CLLR(x)		(0xcc + 0x80 * (x))
44 
45 #define STM32_DMA3_HWCFGR13		0xfc0 /* G_PER_CTRL(X) x=8..15 */
46 #define STM32_DMA3_HWCFGR12		0xfc4 /* G_PER_CTRL(X) x=0..7 */
47 #define STM32_DMA3_HWCFGR4		0xfe4 /* G_FIFO_SIZE(X) x=8..15 */
48 #define STM32_DMA3_HWCFGR3		0xfe8 /* G_FIFO_SIZE(X) x=0..7 */
49 #define STM32_DMA3_HWCFGR2		0xfec /* G_MAX_REQ_ID */
50 #define STM32_DMA3_HWCFGR1		0xff0 /* G_MASTER_PORTS, G_NUM_CHANNELS, G_Mx_DATA_WIDTH */
51 #define STM32_DMA3_VERR			0xff4
52 
53 /* SECCFGR DMA secure configuration register */
54 #define SECCFGR_SEC(x)			BIT(x)
55 
56 /* MISR DMA non-secure/secure masked interrupt status register */
57 #define MISR_MIS(x)			BIT(x)
58 
59 /* CxLBAR DMA channel x linked_list base address register */
60 #define CLBAR_LBA			GENMASK(31, 16)
61 
62 /* CxCIDCFGR DMA channel x CID register */
63 #define CCIDCFGR_CFEN			BIT(0)
64 #define CCIDCFGR_SEM_EN			BIT(1)
65 #define CCIDCFGR_SCID			GENMASK(5, 4)
66 #define CCIDCFGR_SEM_WLIST_CID0		BIT(16)
67 #define CCIDCFGR_SEM_WLIST_CID1		BIT(17)
68 #define CCIDCFGR_SEM_WLIST_CID2		BIT(18)
69 
70 enum ccidcfgr_cid {
71 	CCIDCFGR_CID0,
72 	CCIDCFGR_CID1,
73 	CCIDCFGR_CID2,
74 };
75 
76 /* CxSEMCR DMA channel x semaphore control register */
77 #define CSEMCR_SEM_MUTEX		BIT(0)
78 #define CSEMCR_SEM_CCID			GENMASK(5, 4)
79 
80 /* CxFCR DMA channel x flag clear register */
81 #define CFCR_TCF			BIT(8)
82 #define CFCR_HTF			BIT(9)
83 #define CFCR_DTEF			BIT(10)
84 #define CFCR_ULEF			BIT(11)
85 #define CFCR_USEF			BIT(12)
86 #define CFCR_SUSPF			BIT(13)
87 
88 /* CxSR DMA channel x status register */
89 #define CSR_IDLEF			BIT(0)
90 #define CSR_TCF				BIT(8)
91 #define CSR_HTF				BIT(9)
92 #define CSR_DTEF			BIT(10)
93 #define CSR_ULEF			BIT(11)
94 #define CSR_USEF			BIT(12)
95 #define CSR_SUSPF			BIT(13)
96 #define CSR_ALL_F			GENMASK(13, 8)
97 #define CSR_FIFOL			GENMASK(24, 16)
98 
99 /* CxCR DMA channel x control register */
100 #define CCR_EN				BIT(0)
101 #define CCR_RESET			BIT(1)
102 #define CCR_SUSP			BIT(2)
103 #define CCR_TCIE			BIT(8)
104 #define CCR_HTIE			BIT(9)
105 #define CCR_DTEIE			BIT(10)
106 #define CCR_ULEIE			BIT(11)
107 #define CCR_USEIE			BIT(12)
108 #define CCR_SUSPIE			BIT(13)
109 #define CCR_ALLIE			GENMASK(13, 8)
110 #define CCR_LSM				BIT(16)
111 #define CCR_LAP				BIT(17)
112 #define CCR_PRIO			GENMASK(23, 22)
113 
114 enum ccr_prio {
115 	CCR_PRIO_LOW,
116 	CCR_PRIO_MID,
117 	CCR_PRIO_HIGH,
118 	CCR_PRIO_VERY_HIGH,
119 };
120 
121 /* CxTR1 DMA channel x transfer register 1 */
122 #define CTR1_SINC			BIT(3)
123 #define CTR1_SBL_1			GENMASK(9, 4)
124 #define CTR1_DINC			BIT(19)
125 #define CTR1_DBL_1			GENMASK(25, 20)
126 #define CTR1_SDW_LOG2			GENMASK(1, 0)
127 #define CTR1_PAM			GENMASK(12, 11)
128 #define CTR1_SAP			BIT(14)
129 #define CTR1_DDW_LOG2			GENMASK(17, 16)
130 #define CTR1_DAP			BIT(30)
131 
132 enum ctr1_dw {
133 	CTR1_DW_BYTE,
134 	CTR1_DW_HWORD,
135 	CTR1_DW_WORD,
136 	CTR1_DW_DWORD, /* Depends on HWCFGR1.G_M0_DATA_WIDTH_ENC and .G_M1_DATA_WIDTH_ENC */
137 };
138 
139 enum ctr1_pam {
140 	CTR1_PAM_0S_LT,		/* if DDW > SDW, padded with 0s else left-truncated */
141 	CTR1_PAM_SE_RT,		/* if DDW > SDW, sign extended else right-truncated */
142 	CTR1_PAM_PACK_UNPACK,	/* FIFO queued */
143 };
144 
145 /* CxTR2 DMA channel x transfer register 2 */
146 #define CTR2_REQSEL			GENMASK(7, 0)
147 #define CTR2_SWREQ			BIT(9)
148 #define CTR2_DREQ			BIT(10)
149 #define CTR2_BREQ			BIT(11)
150 #define CTR2_PFREQ			BIT(12)
151 #define CTR2_TCEM			GENMASK(31, 30)
152 
153 enum ctr2_tcem {
154 	CTR2_TCEM_BLOCK,
155 	CTR2_TCEM_REPEAT_BLOCK,
156 	CTR2_TCEM_LLI,
157 	CTR2_TCEM_CHANNEL,
158 };
159 
160 /* CxBR1 DMA channel x block register 1 */
161 #define CBR1_BNDT			GENMASK(15, 0)
162 
163 /* CxLLR DMA channel x linked-list address register */
164 #define CLLR_LA				GENMASK(15, 2)
165 #define CLLR_ULL			BIT(16)
166 #define CLLR_UDA			BIT(27)
167 #define CLLR_USA			BIT(28)
168 #define CLLR_UB1			BIT(29)
169 #define CLLR_UT2			BIT(30)
170 #define CLLR_UT1			BIT(31)
171 
172 /* HWCFGR13 DMA hardware configuration register 13 x=8..15 */
173 /* HWCFGR12 DMA hardware configuration register 12 x=0..7 */
174 #define G_PER_CTRL(x)			(ULL(0x1) << (4 * (x)))
175 
176 /* HWCFGR4 DMA hardware configuration register 4 x=8..15 */
177 /* HWCFGR3 DMA hardware configuration register 3 x=0..7 */
178 #define G_FIFO_SIZE(x)			(ULL(0x7) << (4 * (x)))
179 
180 #define get_chan_hwcfg(x, mask, reg)	(((reg) & (mask)) >> (4 * (x)))
181 
182 /* HWCFGR2 DMA hardware configuration register 2 */
183 #define G_MAX_REQ_ID			GENMASK(7, 0)
184 
185 /* HWCFGR1 DMA hardware configuration register 1 */
186 #define G_MASTER_PORTS			GENMASK(2, 0)
187 #define G_NUM_CHANNELS			GENMASK(12, 8)
188 #define G_M0_DATA_WIDTH_ENC		GENMASK(25, 24)
189 #define G_M1_DATA_WIDTH_ENC		GENMASK(29, 28)
190 
191 enum stm32_dma3_master_ports {
192 	AXI64,		/* 1x AXI: 64-bit port 0 */
193 	AHB32,		/* 1x AHB: 32-bit port 0 */
194 	AHB32_AHB32,	/* 2x AHB: 32-bit port 0 and 32-bit port 1 */
195 	AXI64_AHB32,	/* 1x AXI 64-bit port 0 and 1x AHB 32-bit port 1 */
196 	AXI64_AXI64,	/* 2x AXI: 64-bit port 0 and 64-bit port 1 */
197 	AXI128_AHB32,	/* 1x AXI 128-bit port 0 and 1x AHB 32-bit port 1 */
198 };
199 
200 enum stm32_dma3_port_data_width {
201 	DW_32,		/* 32-bit, for AHB */
202 	DW_64,		/* 64-bit, for AXI */
203 	DW_128,		/* 128-bit, for AXI */
204 	DW_INVALID,
205 };
206 
207 /* VERR DMA version register */
208 #define VERR_MINREV			GENMASK(3, 0)
209 #define VERR_MAJREV			GENMASK(7, 4)
210 
211 /* Device tree */
212 /* struct stm32_dma3_dt_conf */
213 /* .ch_conf */
214 #define STM32_DMA3_DT_PRIO		GENMASK(1, 0) /* CCR_PRIO */
215 #define STM32_DMA3_DT_FIFO		GENMASK(7, 4)
216 /* .tr_conf */
217 #define STM32_DMA3_DT_SINC		BIT(0) /* CTR1_SINC */
218 #define STM32_DMA3_DT_SAP		BIT(1) /* CTR1_SAP */
219 #define STM32_DMA3_DT_DINC		BIT(4) /* CTR1_DINC */
220 #define STM32_DMA3_DT_DAP		BIT(5) /* CTR1_DAP */
221 #define STM32_DMA3_DT_BREQ		BIT(8) /* CTR2_BREQ */
222 #define STM32_DMA3_DT_PFREQ		BIT(9) /* CTR2_PFREQ */
223 #define STM32_DMA3_DT_TCEM		GENMASK(13, 12) /* CTR2_TCEM */
224 #define STM32_DMA3_DT_NOPACK		BIT(16) /* CTR1_PAM */
225 #define STM32_DMA3_DT_NOREFACT		BIT(17)
226 
227 /* struct stm32_dma3_chan .config_set bitfield */
228 #define STM32_DMA3_CFG_SET_DT		BIT(0)
229 #define STM32_DMA3_CFG_SET_DMA		BIT(1)
230 #define STM32_DMA3_CFG_SET_BOTH		(STM32_DMA3_CFG_SET_DT | STM32_DMA3_CFG_SET_DMA)
231 
232 #define STM32_DMA3_MAX_BLOCK_SIZE	ALIGN_DOWN(CBR1_BNDT, 64)
233 #define STM32_DMA3_MAX_BURST_LEN	(1 + min_t(u32, FIELD_MAX(CTR1_SBL_1), \
234 							FIELD_MAX(CTR1_DBL_1)))
235 #define port_is_ahb(maxdw)		({ typeof(maxdw) (_maxdw) = (maxdw); \
236 					   ((_maxdw) != DW_INVALID) && ((_maxdw) == DW_32); })
237 #define port_is_axi(maxdw)		({ typeof(maxdw) (_maxdw) = (maxdw); \
238 					   ((_maxdw) != DW_INVALID) && ((_maxdw) != DW_32); })
239 #define get_chan_max_dw(maxdw, maxburst)((port_is_ahb(maxdw) ||			     \
240 					  (maxburst) < DMA_SLAVE_BUSWIDTH_8_BYTES) ? \
241 					 DMA_SLAVE_BUSWIDTH_4_BYTES : DMA_SLAVE_BUSWIDTH_8_BYTES)
242 
243 /* Static linked-list data structure (depends on update bits UT1/UT2/UB1/USA/UDA/ULL) */
244 struct stm32_dma3_hwdesc {
245 	u32 ctr1;
246 	u32 ctr2;
247 	u32 cbr1;
248 	u32 csar;
249 	u32 cdar;
250 	u32 cllr;
251 } __packed __aligned(32);
252 
253 /*
254  * CLLR_LA / sizeof(struct stm32_dma3_hwdesc) represents the number of hdwdesc that can be addressed
255  * by the pointer to the next linked-list data structure. The __aligned forces the 32-byte
256  * alignment. So use hardcoded 32. Multiplied by the max block size of each item, it represents
257  * the sg size limitation.
258  */
259 #define STM32_DMA3_MAX_SEG_SIZE		((CLLR_LA / 32) * STM32_DMA3_MAX_BLOCK_SIZE)
260 
261 /*
262  * Linked-list items
263  */
264 struct stm32_dma3_lli {
265 	struct stm32_dma3_hwdesc *hwdesc;
266 	dma_addr_t hwdesc_addr;
267 };
268 
269 struct stm32_dma3_swdesc {
270 	struct virt_dma_desc vdesc;
271 	u32 ccr;
272 	bool cyclic;
273 	u32 lli_size;
274 	struct stm32_dma3_lli lli[] __counted_by(lli_size);
275 };
276 
277 struct stm32_dma3_dt_conf {
278 	u32 ch_id;
279 	u32 req_line;
280 	u32 ch_conf;
281 	u32 tr_conf;
282 };
283 
284 struct stm32_dma3_chan {
285 	struct virt_dma_chan vchan;
286 	u32 id;
287 	int irq;
288 	u32 fifo_size;
289 	u32 max_burst;
290 	bool semaphore_mode;
291 	bool semaphore_taken;
292 	struct stm32_dma3_dt_conf dt_config;
293 	struct dma_slave_config dma_config;
294 	u8 config_set;
295 	struct dma_pool *lli_pool;
296 	struct stm32_dma3_swdesc *swdesc;
297 	enum ctr2_tcem tcem;
298 	u32 dma_status;
299 };
300 
301 struct stm32_dma3_pdata {
302 	u32 axi_max_burst_len;
303 };
304 
305 struct stm32_dma3_ddata {
306 	struct dma_device dma_dev;
307 	void __iomem *base;
308 	struct clk *clk;
309 	struct stm32_dma3_chan *chans;
310 	u32 dma_channels;
311 	u32 dma_requests;
312 	enum stm32_dma3_port_data_width ports_max_dw[2];
313 	u32 axi_max_burst_len;
314 };
315 
316 static inline struct stm32_dma3_ddata *to_stm32_dma3_ddata(struct stm32_dma3_chan *chan)
317 {
318 	return container_of(chan->vchan.chan.device, struct stm32_dma3_ddata, dma_dev);
319 }
320 
321 static inline struct stm32_dma3_chan *to_stm32_dma3_chan(struct dma_chan *c)
322 {
323 	return container_of(c, struct stm32_dma3_chan, vchan.chan);
324 }
325 
326 static inline struct stm32_dma3_swdesc *to_stm32_dma3_swdesc(struct virt_dma_desc *vdesc)
327 {
328 	return container_of(vdesc, struct stm32_dma3_swdesc, vdesc);
329 }
330 
331 static struct device *chan2dev(struct stm32_dma3_chan *chan)
332 {
333 	return &chan->vchan.chan.dev->device;
334 }
335 
336 static struct device *ddata2dev(struct stm32_dma3_ddata *ddata)
337 {
338 	return ddata->dma_dev.dev;
339 }
340 
341 static void stm32_dma3_chan_dump_reg(struct stm32_dma3_chan *chan)
342 {
343 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
344 	struct device *dev = chan2dev(chan);
345 	u32 id = chan->id, offset;
346 
347 	offset = STM32_DMA3_SECCFGR;
348 	dev_dbg(dev, "SECCFGR(0x%03x): %08x\n", offset, readl_relaxed(ddata->base + offset));
349 	offset = STM32_DMA3_PRIVCFGR;
350 	dev_dbg(dev, "PRIVCFGR(0x%03x): %08x\n", offset, readl_relaxed(ddata->base + offset));
351 	offset = STM32_DMA3_CCIDCFGR(id);
352 	dev_dbg(dev, "C%dCIDCFGR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
353 	offset = STM32_DMA3_CSEMCR(id);
354 	dev_dbg(dev, "C%dSEMCR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
355 	offset = STM32_DMA3_CSR(id);
356 	dev_dbg(dev, "C%dSR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
357 	offset = STM32_DMA3_CCR(id);
358 	dev_dbg(dev, "C%dCR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
359 	offset = STM32_DMA3_CTR1(id);
360 	dev_dbg(dev, "C%dTR1(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
361 	offset = STM32_DMA3_CTR2(id);
362 	dev_dbg(dev, "C%dTR2(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
363 	offset = STM32_DMA3_CBR1(id);
364 	dev_dbg(dev, "C%dBR1(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
365 	offset = STM32_DMA3_CSAR(id);
366 	dev_dbg(dev, "C%dSAR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
367 	offset = STM32_DMA3_CDAR(id);
368 	dev_dbg(dev, "C%dDAR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
369 	offset = STM32_DMA3_CLLR(id);
370 	dev_dbg(dev, "C%dLLR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
371 	offset = STM32_DMA3_CLBAR(id);
372 	dev_dbg(dev, "C%dLBAR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
373 }
374 
375 static void stm32_dma3_chan_dump_hwdesc(struct stm32_dma3_chan *chan,
376 					struct stm32_dma3_swdesc *swdesc)
377 {
378 	struct stm32_dma3_hwdesc *hwdesc;
379 	int i;
380 
381 	for (i = 0; i < swdesc->lli_size; i++) {
382 		hwdesc = swdesc->lli[i].hwdesc;
383 		if (i)
384 			dev_dbg(chan2dev(chan), "V\n");
385 		dev_dbg(chan2dev(chan), "[%d]@%pad\n", i, &swdesc->lli[i].hwdesc_addr);
386 		dev_dbg(chan2dev(chan), "| C%dTR1: %08x\n", chan->id, hwdesc->ctr1);
387 		dev_dbg(chan2dev(chan), "| C%dTR2: %08x\n", chan->id, hwdesc->ctr2);
388 		dev_dbg(chan2dev(chan), "| C%dBR1: %08x\n", chan->id, hwdesc->cbr1);
389 		dev_dbg(chan2dev(chan), "| C%dSAR: %08x\n", chan->id, hwdesc->csar);
390 		dev_dbg(chan2dev(chan), "| C%dDAR: %08x\n", chan->id, hwdesc->cdar);
391 		dev_dbg(chan2dev(chan), "| C%dLLR: %08x\n", chan->id, hwdesc->cllr);
392 	}
393 
394 	if (swdesc->cyclic) {
395 		dev_dbg(chan2dev(chan), "|\n");
396 		dev_dbg(chan2dev(chan), "-->[0]@%pad\n", &swdesc->lli[0].hwdesc_addr);
397 	} else {
398 		dev_dbg(chan2dev(chan), "X\n");
399 	}
400 }
401 
402 static struct stm32_dma3_swdesc *stm32_dma3_chan_desc_alloc(struct stm32_dma3_chan *chan, u32 count)
403 {
404 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
405 	struct stm32_dma3_swdesc *swdesc;
406 	int i;
407 
408 	/*
409 	 * If the memory to be allocated for the number of hwdesc (6 u32 members but 32-bytes
410 	 * aligned) is greater than the maximum address of CLLR_LA, then the last items can't be
411 	 * addressed, so abort the allocation.
412 	 */
413 	if ((count * 32) > CLLR_LA) {
414 		dev_err(chan2dev(chan), "Transfer is too big (> %luB)\n", STM32_DMA3_MAX_SEG_SIZE);
415 		return NULL;
416 	}
417 
418 	swdesc = kzalloc_flex(*swdesc, lli, count, GFP_NOWAIT);
419 	if (!swdesc)
420 		return NULL;
421 	swdesc->lli_size = count;
422 
423 	for (i = 0; i < count; i++) {
424 		swdesc->lli[i].hwdesc = dma_pool_zalloc(chan->lli_pool, GFP_NOWAIT,
425 							&swdesc->lli[i].hwdesc_addr);
426 		if (!swdesc->lli[i].hwdesc)
427 			goto err_pool_free;
428 	}
429 	swdesc->ccr = 0;
430 
431 	/* Set LL base address */
432 	writel_relaxed(swdesc->lli[0].hwdesc_addr & CLBAR_LBA,
433 		       ddata->base + STM32_DMA3_CLBAR(chan->id));
434 
435 	/* Set LL allocated port */
436 	swdesc->ccr &= ~CCR_LAP;
437 
438 	return swdesc;
439 
440 err_pool_free:
441 	dev_err(chan2dev(chan), "Failed to alloc descriptors\n");
442 	while (--i >= 0)
443 		dma_pool_free(chan->lli_pool, swdesc->lli[i].hwdesc, swdesc->lli[i].hwdesc_addr);
444 	kfree(swdesc);
445 
446 	return NULL;
447 }
448 
449 static void stm32_dma3_chan_desc_free(struct stm32_dma3_chan *chan,
450 				      struct stm32_dma3_swdesc *swdesc)
451 {
452 	int i;
453 
454 	for (i = 0; i < swdesc->lli_size; i++)
455 		dma_pool_free(chan->lli_pool, swdesc->lli[i].hwdesc, swdesc->lli[i].hwdesc_addr);
456 
457 	kfree(swdesc);
458 }
459 
460 static void stm32_dma3_chan_vdesc_free(struct virt_dma_desc *vdesc)
461 {
462 	struct stm32_dma3_swdesc *swdesc = to_stm32_dma3_swdesc(vdesc);
463 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(vdesc->tx.chan);
464 
465 	stm32_dma3_chan_desc_free(chan, swdesc);
466 }
467 
468 static void stm32_dma3_check_user_setting(struct stm32_dma3_chan *chan)
469 {
470 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
471 	struct device *dev = chan2dev(chan);
472 	u32 ctr1 = readl_relaxed(ddata->base + STM32_DMA3_CTR1(chan->id));
473 	u32 cbr1 = readl_relaxed(ddata->base + STM32_DMA3_CBR1(chan->id));
474 	u32 csar = readl_relaxed(ddata->base + STM32_DMA3_CSAR(chan->id));
475 	u32 cdar = readl_relaxed(ddata->base + STM32_DMA3_CDAR(chan->id));
476 	u32 cllr = readl_relaxed(ddata->base + STM32_DMA3_CLLR(chan->id));
477 	u32 bndt = FIELD_GET(CBR1_BNDT, cbr1);
478 	u32 sdw = 1 << FIELD_GET(CTR1_SDW_LOG2, ctr1);
479 	u32 ddw = 1 << FIELD_GET(CTR1_DDW_LOG2, ctr1);
480 	u32 sap = FIELD_GET(CTR1_SAP, ctr1);
481 	u32 dap = FIELD_GET(CTR1_DAP, ctr1);
482 
483 	if (!bndt && !FIELD_GET(CLLR_UB1, cllr))
484 		dev_err(dev, "null source block size and no update of this value\n");
485 	if (bndt % sdw)
486 		dev_err(dev, "source block size not multiple of src data width\n");
487 	if (FIELD_GET(CTR1_PAM, ctr1) == CTR1_PAM_PACK_UNPACK && bndt % ddw)
488 		dev_err(dev, "(un)packing mode w/ src block size not multiple of dst data width\n");
489 	if (csar % sdw)
490 		dev_err(dev, "unaligned source address not multiple of src data width\n");
491 	if (cdar % ddw)
492 		dev_err(dev, "unaligned destination address not multiple of dst data width\n");
493 	if (sdw == DMA_SLAVE_BUSWIDTH_8_BYTES && port_is_ahb(ddata->ports_max_dw[sap]))
494 		dev_err(dev, "double-word source data width not supported on port %u\n", sap);
495 	if (ddw == DMA_SLAVE_BUSWIDTH_8_BYTES && port_is_ahb(ddata->ports_max_dw[dap]))
496 		dev_err(dev, "double-word destination data width not supported on port %u\n", dap);
497 }
498 
499 static void stm32_dma3_chan_prep_hwdesc(struct stm32_dma3_chan *chan,
500 					struct stm32_dma3_swdesc *swdesc,
501 					u32 curr, dma_addr_t src, dma_addr_t dst, u32 len,
502 					u32 ctr1, u32 ctr2, bool is_last, bool is_cyclic)
503 {
504 	struct stm32_dma3_hwdesc *hwdesc;
505 	dma_addr_t next_lli;
506 	u32 next = curr + 1;
507 
508 	hwdesc = swdesc->lli[curr].hwdesc;
509 	hwdesc->ctr1 = ctr1;
510 	hwdesc->ctr2 = ctr2;
511 	hwdesc->cbr1 = FIELD_PREP(CBR1_BNDT, len);
512 	hwdesc->csar = src;
513 	hwdesc->cdar = dst;
514 
515 	if (is_last) {
516 		if (is_cyclic)
517 			next_lli = swdesc->lli[0].hwdesc_addr;
518 		else
519 			next_lli = 0;
520 	} else {
521 		next_lli = swdesc->lli[next].hwdesc_addr;
522 	}
523 
524 	hwdesc->cllr = 0;
525 	if (next_lli) {
526 		hwdesc->cllr |= CLLR_UT1 | CLLR_UT2 | CLLR_UB1;
527 		hwdesc->cllr |= CLLR_USA | CLLR_UDA | CLLR_ULL;
528 		hwdesc->cllr |= (next_lli & CLLR_LA);
529 	}
530 
531 	/*
532 	 * Make sure to flush the CPU's write buffers so that the descriptors are ready to be read
533 	 * by DMA3. By explicitly using a write memory barrier here, instead of doing it with writel
534 	 * to enable the channel, we avoid an unnecessary barrier in the case where the descriptors
535 	 * are reused (DMA_CTRL_REUSE).
536 	 */
537 	if (is_last)
538 		dma_wmb();
539 }
540 
541 static enum dma_slave_buswidth stm32_dma3_get_max_dw(u32 chan_max_burst,
542 						     enum stm32_dma3_port_data_width port_max_dw,
543 						     u32 len, dma_addr_t addr)
544 {
545 	enum dma_slave_buswidth max_dw = get_chan_max_dw(port_max_dw, chan_max_burst);
546 
547 	/* len and addr must be a multiple of dw */
548 	return 1 << __ffs(len | addr | max_dw);
549 }
550 
551 static u32 stm32_dma3_get_max_burst(u32 len, enum dma_slave_buswidth dw,
552 				    u32 chan_max_burst, u32 bus_max_burst)
553 {
554 	u32 max_burst = chan_max_burst ? chan_max_burst / dw : 1;
555 
556 	/* len is a multiple of dw, so if len is < chan_max_burst, shorten burst */
557 	if (len < chan_max_burst)
558 		max_burst = len / dw;
559 
560 	/*
561 	 * HW doesn't modify the burst if burst size <= half of the fifo size.
562 	 * If len is not a multiple of burst size, last burst is shortened by HW.
563 	 * Take care of maximum burst supported on interconnect bus.
564 	 */
565 	return min_t(u32, max_burst, bus_max_burst);
566 }
567 
568 static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transfer_direction dir,
569 				   u32 *ccr, u32 *ctr1, u32 *ctr2,
570 				   dma_addr_t src_addr, dma_addr_t dst_addr, u32 len)
571 {
572 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
573 	struct dma_device dma_device = ddata->dma_dev;
574 	u32 src_max_burst = STM32_DMA3_MAX_BURST_LEN, dst_max_burst = STM32_DMA3_MAX_BURST_LEN;
575 	u32 sdw, ddw, sbl_max, dbl_max, tcem, init_dw, init_bl_max;
576 	u32 _ctr1 = 0, _ctr2 = 0;
577 	u32 ch_conf = chan->dt_config.ch_conf;
578 	u32 tr_conf = chan->dt_config.tr_conf;
579 	u32 sap = FIELD_GET(STM32_DMA3_DT_SAP, tr_conf), sap_max_dw;
580 	u32 dap = FIELD_GET(STM32_DMA3_DT_DAP, tr_conf), dap_max_dw;
581 
582 	dev_dbg(chan2dev(chan), "%s from %pad to %pad\n",
583 		dmaengine_get_direction_text(dir), &src_addr, &dst_addr);
584 
585 	sdw = chan->dma_config.src_addr_width ? : get_chan_max_dw(sap, chan->max_burst);
586 	ddw = chan->dma_config.dst_addr_width ? : get_chan_max_dw(dap, chan->max_burst);
587 	sbl_max = chan->dma_config.src_maxburst ? : 1;
588 	dbl_max = chan->dma_config.dst_maxburst ? : 1;
589 
590 	/* Following conditions would raise User Setting Error interrupt */
591 	if (!(dma_device.src_addr_widths & BIT(sdw)) || !(dma_device.dst_addr_widths & BIT(ddw))) {
592 		dev_err(chan2dev(chan), "Bus width (src=%u, dst=%u) not supported\n", sdw, ddw);
593 		return -EINVAL;
594 	}
595 
596 	if (ddata->ports_max_dw[1] == DW_INVALID && (sap || dap)) {
597 		dev_err(chan2dev(chan), "Only one master port, port 1 is not supported\n");
598 		return -EINVAL;
599 	}
600 
601 	sap_max_dw = ddata->ports_max_dw[sap];
602 	dap_max_dw = ddata->ports_max_dw[dap];
603 	if ((port_is_ahb(sap_max_dw) && sdw == DMA_SLAVE_BUSWIDTH_8_BYTES) ||
604 	    (port_is_ahb(dap_max_dw) && ddw == DMA_SLAVE_BUSWIDTH_8_BYTES)) {
605 		dev_err(chan2dev(chan),
606 			"8 bytes buswidth (src=%u, dst=%u) not supported on port (sap=%u, dap=%u\n",
607 			sdw, ddw, sap, dap);
608 		return -EINVAL;
609 	}
610 
611 	if (FIELD_GET(STM32_DMA3_DT_SINC, tr_conf))
612 		_ctr1 |= CTR1_SINC;
613 	if (sap)
614 		_ctr1 |= CTR1_SAP;
615 	if (port_is_axi(sap_max_dw)) /* AXI - apply axi maximum burst limitation */
616 		src_max_burst = ddata->axi_max_burst_len;
617 	if (FIELD_GET(STM32_DMA3_DT_DINC, tr_conf))
618 		_ctr1 |= CTR1_DINC;
619 	if (dap)
620 		_ctr1 |= CTR1_DAP;
621 	if (port_is_axi(dap_max_dw)) /* AXI - apply axi maximum burst limitation */
622 		dst_max_burst = ddata->axi_max_burst_len;
623 
624 	_ctr2 |= FIELD_PREP(CTR2_REQSEL, chan->dt_config.req_line) & ~CTR2_SWREQ;
625 	if (FIELD_GET(STM32_DMA3_DT_BREQ, tr_conf))
626 		_ctr2 |= CTR2_BREQ;
627 	if (dir == DMA_DEV_TO_MEM && FIELD_GET(STM32_DMA3_DT_PFREQ, tr_conf))
628 		_ctr2 |= CTR2_PFREQ;
629 	tcem = FIELD_GET(STM32_DMA3_DT_TCEM, tr_conf);
630 	_ctr2 |= FIELD_PREP(CTR2_TCEM, tcem);
631 
632 	/* Store TCEM to know on which event TC flag occurred */
633 	chan->tcem = tcem;
634 	/* Store direction for residue computation */
635 	chan->dma_config.direction = dir;
636 
637 	switch (dir) {
638 	case DMA_MEM_TO_DEV:
639 		/* Set destination (device) data width and burst */
640 		ddw = min_t(u32, ddw, stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw,
641 							    len, dst_addr));
642 		dbl_max = min_t(u32, dbl_max, stm32_dma3_get_max_burst(len, ddw, chan->max_burst,
643 								       dst_max_burst));
644 
645 		/* Set source (memory) data width and burst */
646 		sdw = stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr);
647 		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst, src_max_burst);
648 		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf)) {
649 			sdw = ddw;
650 			sbl_max = dbl_max;
651 		}
652 
653 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
654 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);
655 		_ctr1 |= FIELD_PREP(CTR1_DDW_LOG2, ilog2(ddw));
656 		_ctr1 |= FIELD_PREP(CTR1_DBL_1, dbl_max - 1);
657 
658 		if (ddw != sdw) {
659 			_ctr1 |= FIELD_PREP(CTR1_PAM, CTR1_PAM_PACK_UNPACK);
660 			/* Should never reach this case as ddw is clamped down */
661 			if (len & (ddw - 1)) {
662 				dev_err(chan2dev(chan),
663 					"Packing mode is enabled and len is not multiple of ddw");
664 				return -EINVAL;
665 			}
666 		}
667 
668 		/* dst = dev */
669 		_ctr2 |= CTR2_DREQ;
670 
671 		break;
672 
673 	case DMA_DEV_TO_MEM:
674 		/* Set source (device) data width and burst */
675 		sdw = min_t(u32, sdw, stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw,
676 							    len, src_addr));
677 		sbl_max = min_t(u32, sbl_max, stm32_dma3_get_max_burst(len, sdw, chan->max_burst,
678 								       src_max_burst));
679 
680 		/* Set destination (memory) data width and burst */
681 		ddw = stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr);
682 		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst, dst_max_burst);
683 		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf) ||
684 		    ((_ctr2 & CTR2_PFREQ) && ddw > sdw)) { /* Packing to wider ddw not supported */
685 			ddw = sdw;
686 			dbl_max = sbl_max;
687 		}
688 
689 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
690 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);
691 		_ctr1 |= FIELD_PREP(CTR1_DDW_LOG2, ilog2(ddw));
692 		_ctr1 |= FIELD_PREP(CTR1_DBL_1, dbl_max - 1);
693 
694 		if (ddw != sdw) {
695 			_ctr1 |= FIELD_PREP(CTR1_PAM, CTR1_PAM_PACK_UNPACK);
696 			/* Should never reach this case as ddw is clamped down */
697 			if (len & (ddw - 1)) {
698 				dev_err(chan2dev(chan),
699 					"Packing mode is enabled and len is not multiple of ddw\n");
700 				return -EINVAL;
701 			}
702 		}
703 
704 		/* dst = mem */
705 		_ctr2 &= ~CTR2_DREQ;
706 
707 		break;
708 
709 	case DMA_MEM_TO_MEM:
710 		/* Set source (memory) data width and burst */
711 		init_dw = sdw;
712 		init_bl_max = sbl_max;
713 		sdw = stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr);
714 		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst, src_max_burst);
715 		if (chan->config_set & STM32_DMA3_CFG_SET_DMA) {
716 			sdw = min_t(u32, init_dw, sdw);
717 			sbl_max = min_t(u32, init_bl_max, stm32_dma3_get_max_burst(len, sdw,
718 										   chan->max_burst,
719 										   src_max_burst));
720 		}
721 
722 		/* Set destination (memory) data width and burst */
723 		init_dw = ddw;
724 		init_bl_max = dbl_max;
725 		ddw = stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr);
726 		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst, dst_max_burst);
727 		if (chan->config_set & STM32_DMA3_CFG_SET_DMA) {
728 			ddw = min_t(u32, init_dw, ddw);
729 			dbl_max = min_t(u32, init_bl_max, stm32_dma3_get_max_burst(len, ddw,
730 										   chan->max_burst,
731 										   dst_max_burst));
732 		}
733 
734 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
735 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);
736 		_ctr1 |= FIELD_PREP(CTR1_DDW_LOG2, ilog2(ddw));
737 		_ctr1 |= FIELD_PREP(CTR1_DBL_1, dbl_max - 1);
738 
739 		if (ddw != sdw) {
740 			_ctr1 |= FIELD_PREP(CTR1_PAM, CTR1_PAM_PACK_UNPACK);
741 			/* Should never reach this case as ddw is clamped down */
742 			if (len & (ddw - 1)) {
743 				dev_err(chan2dev(chan),
744 					"Packing mode is enabled and len is not multiple of ddw");
745 				return -EINVAL;
746 			}
747 		}
748 
749 		/* CTR2_REQSEL/DREQ/BREQ/PFREQ are ignored with CTR2_SWREQ=1 */
750 		_ctr2 |= CTR2_SWREQ;
751 
752 		break;
753 
754 	default:
755 		dev_err(chan2dev(chan), "Direction %s not supported\n",
756 			dmaengine_get_direction_text(dir));
757 		return -EINVAL;
758 	}
759 
760 	*ccr |= FIELD_PREP(CCR_PRIO, FIELD_GET(STM32_DMA3_DT_PRIO, ch_conf));
761 	*ctr1 = _ctr1;
762 	*ctr2 = _ctr2;
763 
764 	dev_dbg(chan2dev(chan), "%s: sdw=%u bytes sbl=%u beats ddw=%u bytes dbl=%u beats\n",
765 		__func__, sdw, sbl_max, ddw, dbl_max);
766 
767 	return 0;
768 }
769 
770 static void stm32_dma3_chan_start(struct stm32_dma3_chan *chan)
771 {
772 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
773 	struct virt_dma_desc *vdesc;
774 	struct stm32_dma3_hwdesc *hwdesc;
775 	u32 id = chan->id;
776 	u32 csr, ccr;
777 
778 	vdesc = vchan_next_desc(&chan->vchan);
779 	if (!vdesc) {
780 		chan->swdesc = NULL;
781 		return;
782 	}
783 	list_del(&vdesc->node);
784 
785 	chan->swdesc = to_stm32_dma3_swdesc(vdesc);
786 	hwdesc = chan->swdesc->lli[0].hwdesc;
787 
788 	stm32_dma3_chan_dump_hwdesc(chan, chan->swdesc);
789 
790 	writel_relaxed(chan->swdesc->ccr, ddata->base + STM32_DMA3_CCR(id));
791 	writel_relaxed(hwdesc->ctr1, ddata->base + STM32_DMA3_CTR1(id));
792 	writel_relaxed(hwdesc->ctr2, ddata->base + STM32_DMA3_CTR2(id));
793 	writel_relaxed(hwdesc->cbr1, ddata->base + STM32_DMA3_CBR1(id));
794 	writel_relaxed(hwdesc->csar, ddata->base + STM32_DMA3_CSAR(id));
795 	writel_relaxed(hwdesc->cdar, ddata->base + STM32_DMA3_CDAR(id));
796 	writel_relaxed(hwdesc->cllr, ddata->base + STM32_DMA3_CLLR(id));
797 
798 	/* Clear any pending interrupts */
799 	csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(id));
800 	if (csr & CSR_ALL_F)
801 		writel_relaxed(csr, ddata->base + STM32_DMA3_CFCR(id));
802 
803 	stm32_dma3_chan_dump_reg(chan);
804 
805 	ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(id));
806 	writel_relaxed(ccr | CCR_EN, ddata->base + STM32_DMA3_CCR(id));
807 
808 	chan->dma_status = DMA_IN_PROGRESS;
809 
810 	dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);
811 }
812 
813 static int stm32_dma3_chan_suspend(struct stm32_dma3_chan *chan, bool susp)
814 {
815 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
816 	u32 csr, ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) & ~CCR_EN;
817 	int ret = 0;
818 
819 	if (susp)
820 		ccr |= CCR_SUSP;
821 	else
822 		ccr &= ~CCR_SUSP;
823 
824 	writel_relaxed(ccr, ddata->base + STM32_DMA3_CCR(chan->id));
825 
826 	if (susp) {
827 		ret = readl_relaxed_poll_timeout_atomic(ddata->base + STM32_DMA3_CSR(chan->id), csr,
828 							csr & CSR_SUSPF, 1, 10);
829 		if (!ret)
830 			writel_relaxed(CFCR_SUSPF, ddata->base + STM32_DMA3_CFCR(chan->id));
831 
832 		stm32_dma3_chan_dump_reg(chan);
833 	}
834 
835 	return ret;
836 }
837 
838 static void stm32_dma3_chan_reset(struct stm32_dma3_chan *chan)
839 {
840 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
841 	u32 ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) & ~CCR_EN;
842 
843 	writel_relaxed(ccr |= CCR_RESET, ddata->base + STM32_DMA3_CCR(chan->id));
844 }
845 
846 static int stm32_dma3_chan_get_curr_hwdesc(struct stm32_dma3_swdesc *swdesc, u32 cllr, u32 *residue)
847 {
848 	u32 i, lli_offset, next_lli_offset = cllr & CLLR_LA;
849 
850 	/* If cllr is null, it means it is either the last or single item */
851 	if (!cllr)
852 		return swdesc->lli_size - 1;
853 
854 	/* In cyclic mode, go fast and first check we are not on the last item */
855 	if (swdesc->cyclic && next_lli_offset == (swdesc->lli[0].hwdesc_addr & CLLR_LA))
856 		return swdesc->lli_size - 1;
857 
858 	/* As transfer is in progress, look backward from the last item */
859 	for (i = swdesc->lli_size - 1; i > 0; i--) {
860 		*residue += FIELD_GET(CBR1_BNDT, swdesc->lli[i].hwdesc->cbr1);
861 		lli_offset = swdesc->lli[i].hwdesc_addr & CLLR_LA;
862 		if (lli_offset == next_lli_offset)
863 			return i - 1;
864 	}
865 
866 	return -EINVAL;
867 }
868 
869 static void stm32_dma3_chan_set_residue(struct stm32_dma3_chan *chan,
870 					struct stm32_dma3_swdesc *swdesc,
871 					struct dma_tx_state *txstate)
872 {
873 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
874 	struct device *dev = chan2dev(chan);
875 	struct stm32_dma3_hwdesc *hwdesc;
876 	u32 residue, curr_lli, csr, cdar, cbr1, cllr, bndt, fifol;
877 	bool pack_unpack;
878 	int ret;
879 
880 	csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(chan->id));
881 	if (!(csr & CSR_IDLEF) && chan->dma_status != DMA_PAUSED) {
882 		/* Suspend current transfer to read registers for a snapshot */
883 		writel_relaxed(swdesc->ccr | CCR_SUSP, ddata->base + STM32_DMA3_CCR(chan->id));
884 		ret = readl_relaxed_poll_timeout_atomic(ddata->base + STM32_DMA3_CSR(chan->id), csr,
885 							csr & (CSR_SUSPF | CSR_IDLEF), 1, 10);
886 
887 		if (ret || ((csr & CSR_TCF) && (csr & CSR_IDLEF))) {
888 			writel_relaxed(CFCR_SUSPF, ddata->base + STM32_DMA3_CFCR(chan->id));
889 			writel_relaxed(swdesc->ccr, ddata->base + STM32_DMA3_CCR(chan->id));
890 			if (ret)
891 				dev_err(dev, "Channel suspension timeout, csr=%08x\n", csr);
892 		}
893 	}
894 
895 	/* If channel is still active (CSR_IDLEF is not set), can't get a reliable residue */
896 	if (!(csr & CSR_IDLEF))
897 		dev_warn(dev, "Can't get residue: channel still active, csr=%08x\n", csr);
898 
899 	/*
900 	 * If channel is not suspended, but Idle and Transfer Complete are set,
901 	 * linked-list is over, no residue
902 	 */
903 	if (!(csr & CSR_SUSPF) && (csr & CSR_TCF) && (csr & CSR_IDLEF))
904 		return;
905 
906 	/* Read registers to have a snapshot */
907 	cllr = readl_relaxed(ddata->base + STM32_DMA3_CLLR(chan->id));
908 	cbr1 = readl_relaxed(ddata->base + STM32_DMA3_CBR1(chan->id));
909 	cdar = readl_relaxed(ddata->base + STM32_DMA3_CDAR(chan->id));
910 
911 	/* Resume current transfer */
912 	if (csr & CSR_SUSPF) {
913 		writel_relaxed(CFCR_SUSPF, ddata->base + STM32_DMA3_CFCR(chan->id));
914 		writel_relaxed(swdesc->ccr, ddata->base + STM32_DMA3_CCR(chan->id));
915 	}
916 
917 	/* Add current BNDT */
918 	bndt = FIELD_GET(CBR1_BNDT, cbr1);
919 	residue = bndt;
920 
921 	/* Get current hwdesc and cumulate residue of pending hwdesc BNDT */
922 	ret = stm32_dma3_chan_get_curr_hwdesc(swdesc, cllr, &residue);
923 	if (ret < 0) {
924 		dev_err(chan2dev(chan), "Can't get residue: current hwdesc not found\n");
925 		return;
926 	}
927 	curr_lli = ret;
928 
929 	/* Read current FIFO level - in units of programmed destination data width */
930 	hwdesc = swdesc->lli[curr_lli].hwdesc;
931 	fifol = FIELD_GET(CSR_FIFOL, csr) * (1 << FIELD_GET(CTR1_DDW_LOG2, hwdesc->ctr1));
932 	/* If the FIFO contains as many bytes as its size, it can't contain more */
933 	if (fifol == (1 << (chan->fifo_size + 1)))
934 		goto skip_fifol_update;
935 
936 	/*
937 	 * In case of PACKING (Destination burst length > Source burst length) or UNPACKING
938 	 * (Source burst length > Destination burst length), bytes could be pending in the FIFO
939 	 * (to be packed up to Destination burst length or unpacked into Destination burst length
940 	 * chunks).
941 	 * BNDT is not reliable, as it reflects the number of bytes read from the source but not the
942 	 * number of bytes written to the destination.
943 	 * FIFOL is also not sufficient, because it reflects the number of available write beats in
944 	 * units of Destination data width but not the bytes not yet packed or unpacked.
945 	 * In case of Destination increment DINC, it is possible to compute the number of bytes in
946 	 * the FIFO:
947 	 * fifol_in_bytes = bytes_read - bytes_written.
948 	 */
949 	pack_unpack = !!(FIELD_GET(CTR1_PAM, hwdesc->ctr1) == CTR1_PAM_PACK_UNPACK);
950 	if (pack_unpack && (hwdesc->ctr1 & CTR1_DINC)) {
951 		int bytes_read = FIELD_GET(CBR1_BNDT, hwdesc->cbr1) - bndt;
952 		int bytes_written = cdar - hwdesc->cdar;
953 
954 		if (bytes_read > 0)
955 			fifol = bytes_read - bytes_written;
956 	}
957 
958 skip_fifol_update:
959 	if (fifol) {
960 		dev_dbg(chan2dev(chan), "%u byte(s) in the FIFO\n", fifol);
961 		dma_set_in_flight_bytes(txstate, fifol);
962 		/*
963 		 * Residue is already accurate for DMA_MEM_TO_DEV as BNDT reflects data read from
964 		 * the source memory buffer, so just need to add fifol to residue in case of
965 		 * DMA_DEV_TO_MEM transfer because these bytes are not yet written in destination
966 		 * memory buffer.
967 		 */
968 		if (chan->dma_config.direction == DMA_DEV_TO_MEM)
969 			residue += fifol;
970 	}
971 	dma_set_residue(txstate, residue);
972 }
973 
974 static int stm32_dma3_chan_stop(struct stm32_dma3_chan *chan)
975 {
976 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
977 	u32 ccr;
978 	int ret = 0;
979 
980 	chan->dma_status = DMA_COMPLETE;
981 
982 	/* Disable interrupts */
983 	ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id));
984 	writel_relaxed(ccr & ~(CCR_ALLIE | CCR_EN), ddata->base + STM32_DMA3_CCR(chan->id));
985 
986 	if (!(ccr & CCR_SUSP) && (ccr & CCR_EN)) {
987 		/* Suspend the channel */
988 		ret = stm32_dma3_chan_suspend(chan, true);
989 		if (ret)
990 			dev_warn(chan2dev(chan), "%s: timeout, data might be lost\n", __func__);
991 	}
992 
993 	/*
994 	 * Reset the channel: this causes the reset of the FIFO and the reset of the channel
995 	 * internal state, the reset of CCR_EN and CCR_SUSP bits.
996 	 */
997 	stm32_dma3_chan_reset(chan);
998 
999 	return ret;
1000 }
1001 
1002 static void stm32_dma3_chan_complete(struct stm32_dma3_chan *chan)
1003 {
1004 	if (!chan->swdesc)
1005 		return;
1006 
1007 	vchan_cookie_complete(&chan->swdesc->vdesc);
1008 	chan->swdesc = NULL;
1009 	stm32_dma3_chan_start(chan);
1010 }
1011 
1012 static irqreturn_t stm32_dma3_chan_irq(int irq, void *devid)
1013 {
1014 	struct stm32_dma3_chan *chan = devid;
1015 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1016 	u32 misr, csr, ccr;
1017 
1018 	spin_lock(&chan->vchan.lock);
1019 
1020 	misr = readl_relaxed(ddata->base + STM32_DMA3_MISR);
1021 	if (!(misr & MISR_MIS(chan->id))) {
1022 		spin_unlock(&chan->vchan.lock);
1023 		return IRQ_NONE;
1024 	}
1025 
1026 	csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(chan->id));
1027 	ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) & CCR_ALLIE;
1028 
1029 	if (csr & CSR_TCF && ccr & CCR_TCIE) {
1030 		if (chan->swdesc->cyclic)
1031 			vchan_cyclic_callback(&chan->swdesc->vdesc);
1032 		else
1033 			stm32_dma3_chan_complete(chan);
1034 	}
1035 
1036 	if (csr & CSR_USEF && ccr & CCR_USEIE) {
1037 		dev_err(chan2dev(chan), "User setting error\n");
1038 		chan->dma_status = DMA_ERROR;
1039 		/* CCR.EN automatically cleared by HW */
1040 		stm32_dma3_check_user_setting(chan);
1041 		stm32_dma3_chan_reset(chan);
1042 	}
1043 
1044 	if (csr & CSR_ULEF && ccr & CCR_ULEIE) {
1045 		dev_err(chan2dev(chan), "Update link transfer error\n");
1046 		chan->dma_status = DMA_ERROR;
1047 		/* CCR.EN automatically cleared by HW */
1048 		stm32_dma3_chan_reset(chan);
1049 	}
1050 
1051 	if (csr & CSR_DTEF && ccr & CCR_DTEIE) {
1052 		dev_err(chan2dev(chan), "Data transfer error\n");
1053 		chan->dma_status = DMA_ERROR;
1054 		/* CCR.EN automatically cleared by HW */
1055 		stm32_dma3_chan_reset(chan);
1056 	}
1057 
1058 	/*
1059 	 * Half Transfer Interrupt may be disabled but Half Transfer Flag can be set,
1060 	 * ensure HTF flag to be cleared, with other flags.
1061 	 */
1062 	csr &= (ccr | CCR_HTIE);
1063 
1064 	if (csr)
1065 		writel_relaxed(csr, ddata->base + STM32_DMA3_CFCR(chan->id));
1066 
1067 	spin_unlock(&chan->vchan.lock);
1068 
1069 	return IRQ_HANDLED;
1070 }
1071 
1072 static int stm32_dma3_get_chan_sem(struct stm32_dma3_chan *chan)
1073 {
1074 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1075 	u32 csemcr, ccid;
1076 
1077 	csemcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id));
1078 	/* Make an attempt to take the channel semaphore if not already taken */
1079 	if (!(csemcr & CSEMCR_SEM_MUTEX)) {
1080 		writel_relaxed(CSEMCR_SEM_MUTEX, ddata->base + STM32_DMA3_CSEMCR(chan->id));
1081 		csemcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id));
1082 	}
1083 
1084 	/* Check if channel is under CID1 control */
1085 	ccid = FIELD_GET(CSEMCR_SEM_CCID, csemcr);
1086 	if (!(csemcr & CSEMCR_SEM_MUTEX) || ccid != CCIDCFGR_CID1)
1087 		goto bad_cid;
1088 
1089 	chan->semaphore_taken = true;
1090 	dev_dbg(chan2dev(chan), "under CID1 control (semcr=0x%08x)\n", csemcr);
1091 
1092 	return 0;
1093 
1094 bad_cid:
1095 	chan->semaphore_taken = false;
1096 	dev_err(chan2dev(chan), "not under CID1 control (in-use by CID%d)\n", ccid);
1097 
1098 	return -EACCES;
1099 }
1100 
1101 static void stm32_dma3_put_chan_sem(struct stm32_dma3_chan *chan)
1102 {
1103 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1104 
1105 	if (chan->semaphore_taken) {
1106 		writel_relaxed(0, ddata->base + STM32_DMA3_CSEMCR(chan->id));
1107 		chan->semaphore_taken = false;
1108 		dev_dbg(chan2dev(chan), "no more under CID1 control\n");
1109 	}
1110 }
1111 
1112 static int stm32_dma3_alloc_chan_resources(struct dma_chan *c)
1113 {
1114 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1115 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1116 	int ret;
1117 
1118 	ret = pm_runtime_resume_and_get(ddata2dev(ddata));
1119 	if (ret < 0)
1120 		return ret;
1121 
1122 	/* Ensure the channel is free */
1123 	if (chan->semaphore_mode &&
1124 	    readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id)) & CSEMCR_SEM_MUTEX) {
1125 		ret = -EBUSY;
1126 		goto err_put_sync;
1127 	}
1128 
1129 	chan->lli_pool = dmam_pool_create(dev_name(&c->dev->device), c->device->dev,
1130 					  sizeof(struct stm32_dma3_hwdesc),
1131 					  __alignof__(struct stm32_dma3_hwdesc), SZ_64K);
1132 	if (!chan->lli_pool) {
1133 		dev_err(chan2dev(chan), "Failed to create LLI pool\n");
1134 		ret = -ENOMEM;
1135 		goto err_put_sync;
1136 	}
1137 
1138 	/* Take the channel semaphore */
1139 	if (chan->semaphore_mode) {
1140 		ret = stm32_dma3_get_chan_sem(chan);
1141 		if (ret)
1142 			goto err_pool_destroy;
1143 	}
1144 
1145 	return 0;
1146 
1147 err_pool_destroy:
1148 	dmam_pool_destroy(chan->lli_pool);
1149 	chan->lli_pool = NULL;
1150 
1151 err_put_sync:
1152 	pm_runtime_put_sync(ddata2dev(ddata));
1153 
1154 	return ret;
1155 }
1156 
1157 static void stm32_dma3_free_chan_resources(struct dma_chan *c)
1158 {
1159 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1160 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1161 	unsigned long flags;
1162 
1163 	/* Ensure channel is in idle state */
1164 	spin_lock_irqsave(&chan->vchan.lock, flags);
1165 	stm32_dma3_chan_stop(chan);
1166 	chan->swdesc = NULL;
1167 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1168 
1169 	vchan_free_chan_resources(to_virt_chan(c));
1170 
1171 	dmam_pool_destroy(chan->lli_pool);
1172 	chan->lli_pool = NULL;
1173 
1174 	/* Release the channel semaphore */
1175 	if (chan->semaphore_mode)
1176 		stm32_dma3_put_chan_sem(chan);
1177 
1178 	pm_runtime_put_sync(ddata2dev(ddata));
1179 
1180 	/* Reset configuration */
1181 	memset(&chan->dt_config, 0, sizeof(chan->dt_config));
1182 	memset(&chan->dma_config, 0, sizeof(chan->dma_config));
1183 	chan->config_set = 0;
1184 }
1185 
1186 static u32 stm32_dma3_get_ll_count(struct stm32_dma3_chan *chan, size_t len, bool prevent_refactor)
1187 {
1188 	u32 count;
1189 
1190 	if (prevent_refactor)
1191 		return DIV_ROUND_UP(len, STM32_DMA3_MAX_BLOCK_SIZE);
1192 
1193 	count = len / STM32_DMA3_MAX_BLOCK_SIZE;
1194 	len -= (len / STM32_DMA3_MAX_BLOCK_SIZE) * STM32_DMA3_MAX_BLOCK_SIZE;
1195 
1196 	if (len >= chan->max_burst) {
1197 		count += 1; /* len < STM32_DMA3_MAX_BLOCK_SIZE here, so it fits in one item */
1198 		len -= (len / chan->max_burst) * chan->max_burst;
1199 	}
1200 
1201 	/* Unaligned remainder fits in one extra item */
1202 	if (len > 0)
1203 		count += 1;
1204 
1205 	return count;
1206 }
1207 
1208 static void stm32_dma3_init_chan_config_for_memcpy(struct stm32_dma3_chan *chan,
1209 						   dma_addr_t dst, dma_addr_t src)
1210 {
1211 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1212 	u32 dw = get_chan_max_dw(ddata->ports_max_dw[0], chan->max_burst); /* port 0 by default */
1213 	u32 burst = chan->max_burst / dw;
1214 
1215 	/* Initialize dt_config if channel not pre-configured through DT */
1216 	if (!(chan->config_set & STM32_DMA3_CFG_SET_DT)) {
1217 		chan->dt_config.ch_conf = FIELD_PREP(STM32_DMA3_DT_PRIO, CCR_PRIO_VERY_HIGH);
1218 		chan->dt_config.ch_conf |= FIELD_PREP(STM32_DMA3_DT_FIFO, chan->fifo_size);
1219 		chan->dt_config.tr_conf = STM32_DMA3_DT_SINC | STM32_DMA3_DT_DINC;
1220 		chan->dt_config.tr_conf |= FIELD_PREP(STM32_DMA3_DT_TCEM, CTR2_TCEM_CHANNEL);
1221 	}
1222 
1223 	/* Initialize dma_config if dmaengine_slave_config() not used */
1224 	if (!(chan->config_set & STM32_DMA3_CFG_SET_DMA)) {
1225 		chan->dma_config.src_addr_width = dw;
1226 		chan->dma_config.dst_addr_width = dw;
1227 		chan->dma_config.src_maxburst = burst;
1228 		chan->dma_config.dst_maxburst = burst;
1229 		chan->dma_config.src_addr = src;
1230 		chan->dma_config.dst_addr = dst;
1231 	}
1232 }
1233 
1234 static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_memcpy(struct dma_chan *c,
1235 								  dma_addr_t dst, dma_addr_t src,
1236 								  size_t len, unsigned long flags)
1237 {
1238 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1239 	struct stm32_dma3_swdesc *swdesc;
1240 	size_t next_size, offset;
1241 	u32 count, i, ctr1, ctr2;
1242 	bool prevent_refactor = !!FIELD_GET(STM32_DMA3_DT_NOPACK, chan->dt_config.tr_conf) ||
1243 				!!FIELD_GET(STM32_DMA3_DT_NOREFACT, chan->dt_config.tr_conf);
1244 
1245 	/* Semaphore could be lost during suspend/resume */
1246 	if (chan->semaphore_mode && !chan->semaphore_taken)
1247 		return NULL;
1248 
1249 	count = stm32_dma3_get_ll_count(chan, len, prevent_refactor);
1250 
1251 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
1252 	if (!swdesc)
1253 		return NULL;
1254 
1255 	if (chan->config_set != STM32_DMA3_CFG_SET_BOTH)
1256 		stm32_dma3_init_chan_config_for_memcpy(chan, dst, src);
1257 
1258 	for (i = 0, offset = 0; offset < len; i++, offset += next_size) {
1259 		size_t remaining;
1260 		int ret;
1261 
1262 		remaining = len - offset;
1263 		next_size = min_t(size_t, remaining, STM32_DMA3_MAX_BLOCK_SIZE);
1264 
1265 		if (!prevent_refactor &&
1266 		    (next_size < STM32_DMA3_MAX_BLOCK_SIZE && next_size >= chan->max_burst))
1267 			next_size = chan->max_burst * (remaining / chan->max_burst);
1268 
1269 		ret = stm32_dma3_chan_prep_hw(chan, DMA_MEM_TO_MEM, &swdesc->ccr, &ctr1, &ctr2,
1270 					      src + offset, dst + offset, next_size);
1271 		if (ret)
1272 			goto err_desc_free;
1273 
1274 		stm32_dma3_chan_prep_hwdesc(chan, swdesc, i, src + offset, dst + offset, next_size,
1275 					    ctr1, ctr2, next_size == remaining, false);
1276 	}
1277 
1278 	/* Enable Errors interrupts */
1279 	swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
1280 	/* Enable Transfer state interrupts */
1281 	swdesc->ccr |= CCR_TCIE;
1282 
1283 	swdesc->cyclic = false;
1284 
1285 	return vchan_tx_prep(&chan->vchan, &swdesc->vdesc, flags);
1286 
1287 err_desc_free:
1288 	stm32_dma3_chan_desc_free(chan, swdesc);
1289 
1290 	return NULL;
1291 }
1292 
1293 static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct dma_chan *c,
1294 								struct scatterlist *sgl,
1295 								unsigned int sg_len,
1296 								enum dma_transfer_direction dir,
1297 								unsigned long flags, void *context)
1298 {
1299 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1300 	struct stm32_dma3_swdesc *swdesc;
1301 	struct scatterlist *sg;
1302 	size_t len;
1303 	dma_addr_t sg_addr, dev_addr, src, dst;
1304 	u32 i, j, count, ctr1, ctr2;
1305 	bool prevent_refactor = !!FIELD_GET(STM32_DMA3_DT_NOPACK, chan->dt_config.tr_conf) ||
1306 				!!FIELD_GET(STM32_DMA3_DT_NOREFACT, chan->dt_config.tr_conf);
1307 	int ret;
1308 
1309 	/* Semaphore could be lost during suspend/resume */
1310 	if (chan->semaphore_mode && !chan->semaphore_taken)
1311 		return NULL;
1312 
1313 	count = 0;
1314 	for_each_sg(sgl, sg, sg_len, i)
1315 		count += stm32_dma3_get_ll_count(chan, sg_dma_len(sg), prevent_refactor);
1316 
1317 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
1318 	if (!swdesc)
1319 		return NULL;
1320 
1321 	/* sg_len and i correspond to the initial sgl; count and j correspond to the hwdesc LL */
1322 	j = 0;
1323 	for_each_sg(sgl, sg, sg_len, i) {
1324 		sg_addr = sg_dma_address(sg);
1325 		dev_addr = (dir == DMA_MEM_TO_DEV) ? chan->dma_config.dst_addr :
1326 						     chan->dma_config.src_addr;
1327 		len = sg_dma_len(sg);
1328 
1329 		do {
1330 			size_t chunk = min_t(size_t, len, STM32_DMA3_MAX_BLOCK_SIZE);
1331 
1332 			if (!prevent_refactor &&
1333 			    (chunk < STM32_DMA3_MAX_BLOCK_SIZE && chunk >= chan->max_burst))
1334 				chunk = chan->max_burst * (len / chan->max_burst);
1335 
1336 			if (dir == DMA_MEM_TO_DEV) {
1337 				src = sg_addr;
1338 				dst = dev_addr;
1339 
1340 				ret = stm32_dma3_chan_prep_hw(chan, dir, &swdesc->ccr, &ctr1, &ctr2,
1341 							      src, dst, chunk);
1342 
1343 				if (FIELD_GET(CTR1_DINC, ctr1))
1344 					dev_addr += chunk;
1345 			} else { /* (dir == DMA_DEV_TO_MEM || dir == DMA_MEM_TO_MEM) */
1346 				src = dev_addr;
1347 				dst = sg_addr;
1348 
1349 				ret = stm32_dma3_chan_prep_hw(chan, dir, &swdesc->ccr, &ctr1, &ctr2,
1350 							      src, dst, chunk);
1351 
1352 				if (FIELD_GET(CTR1_SINC, ctr1))
1353 					dev_addr += chunk;
1354 			}
1355 
1356 			if (ret)
1357 				goto err_desc_free;
1358 
1359 			stm32_dma3_chan_prep_hwdesc(chan, swdesc, j, src, dst, chunk,
1360 						    ctr1, ctr2, j == (count - 1), false);
1361 
1362 			sg_addr += chunk;
1363 			len -= chunk;
1364 			j++;
1365 		} while (len);
1366 	}
1367 
1368 	if (count != sg_len && chan->tcem != CTR2_TCEM_CHANNEL)
1369 		dev_warn(chan2dev(chan), "Linked-list refactored, %d items instead of %d\n",
1370 			 count, sg_len);
1371 
1372 	/* Enable Error interrupts */
1373 	swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
1374 	/* Enable Transfer state interrupts */
1375 	swdesc->ccr |= CCR_TCIE;
1376 
1377 	swdesc->cyclic = false;
1378 
1379 	return vchan_tx_prep(&chan->vchan, &swdesc->vdesc, flags);
1380 
1381 err_desc_free:
1382 	stm32_dma3_chan_desc_free(chan, swdesc);
1383 
1384 	return NULL;
1385 }
1386 
1387 static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_cyclic(struct dma_chan *c,
1388 								  dma_addr_t buf_addr,
1389 								  size_t buf_len, size_t period_len,
1390 								  enum dma_transfer_direction dir,
1391 								  unsigned long flags)
1392 {
1393 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1394 	struct stm32_dma3_swdesc *swdesc;
1395 	dma_addr_t src, dst;
1396 	u32 count, i, ctr1, ctr2;
1397 	int ret;
1398 
1399 	/* Semaphore could be lost during suspend/resume */
1400 	if (chan->semaphore_mode && !chan->semaphore_taken)
1401 		return NULL;
1402 
1403 	if (!buf_len || !period_len || period_len > STM32_DMA3_MAX_BLOCK_SIZE) {
1404 		dev_err(chan2dev(chan), "Invalid buffer/period length\n");
1405 		return NULL;
1406 	}
1407 
1408 	if (buf_len % period_len) {
1409 		dev_err(chan2dev(chan), "Buffer length not multiple of period length\n");
1410 		return NULL;
1411 	}
1412 
1413 	count = buf_len / period_len;
1414 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
1415 	if (!swdesc)
1416 		return NULL;
1417 
1418 	if (dir == DMA_MEM_TO_DEV) {
1419 		src = buf_addr;
1420 		dst = chan->dma_config.dst_addr;
1421 
1422 		ret = stm32_dma3_chan_prep_hw(chan, DMA_MEM_TO_DEV, &swdesc->ccr, &ctr1, &ctr2,
1423 					      src, dst, period_len);
1424 	} else if (dir == DMA_DEV_TO_MEM) {
1425 		src = chan->dma_config.src_addr;
1426 		dst = buf_addr;
1427 
1428 		ret = stm32_dma3_chan_prep_hw(chan, DMA_DEV_TO_MEM, &swdesc->ccr, &ctr1, &ctr2,
1429 					      src, dst, period_len);
1430 	} else {
1431 		dev_err(chan2dev(chan), "Invalid direction\n");
1432 		ret = -EINVAL;
1433 	}
1434 
1435 	if (ret)
1436 		goto err_desc_free;
1437 
1438 	for (i = 0; i < count; i++) {
1439 		if (dir == DMA_MEM_TO_DEV) {
1440 			src = buf_addr + i * period_len;
1441 			dst = chan->dma_config.dst_addr;
1442 		} else { /* (dir == DMA_DEV_TO_MEM) */
1443 			src = chan->dma_config.src_addr;
1444 			dst = buf_addr + i * period_len;
1445 		}
1446 
1447 		stm32_dma3_chan_prep_hwdesc(chan, swdesc, i, src, dst, period_len,
1448 					    ctr1, ctr2, i == (count - 1), true);
1449 	}
1450 
1451 	/* Enable Error interrupts */
1452 	swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
1453 	/* Enable Transfer state interrupts */
1454 	swdesc->ccr |= CCR_TCIE;
1455 
1456 	swdesc->cyclic = true;
1457 
1458 	return vchan_tx_prep(&chan->vchan, &swdesc->vdesc, flags);
1459 
1460 err_desc_free:
1461 	stm32_dma3_chan_desc_free(chan, swdesc);
1462 
1463 	return NULL;
1464 }
1465 
1466 static void stm32_dma3_caps(struct dma_chan *c, struct dma_slave_caps *caps)
1467 {
1468 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1469 
1470 	if (!chan->fifo_size) {
1471 		caps->max_burst = 0;
1472 		caps->src_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1473 		caps->dst_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1474 	} else {
1475 		/* Burst transfer should not exceed half of the fifo size */
1476 		caps->max_burst = chan->max_burst;
1477 		if (caps->max_burst < DMA_SLAVE_BUSWIDTH_8_BYTES) {
1478 			caps->src_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1479 			caps->dst_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1480 		}
1481 	}
1482 }
1483 
1484 static int stm32_dma3_config(struct dma_chan *c, struct dma_slave_config *config)
1485 {
1486 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1487 
1488 	memcpy(&chan->dma_config, config, sizeof(*config));
1489 	chan->config_set |= STM32_DMA3_CFG_SET_DMA;
1490 
1491 	return 0;
1492 }
1493 
1494 static int stm32_dma3_pause(struct dma_chan *c)
1495 {
1496 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1497 	int ret;
1498 
1499 	ret = stm32_dma3_chan_suspend(chan, true);
1500 	if (ret)
1501 		return ret;
1502 
1503 	chan->dma_status = DMA_PAUSED;
1504 
1505 	dev_dbg(chan2dev(chan), "vchan %p: paused\n", &chan->vchan);
1506 
1507 	return 0;
1508 }
1509 
1510 static int stm32_dma3_resume(struct dma_chan *c)
1511 {
1512 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1513 
1514 	stm32_dma3_chan_suspend(chan, false);
1515 
1516 	chan->dma_status = DMA_IN_PROGRESS;
1517 
1518 	dev_dbg(chan2dev(chan), "vchan %p: resumed\n", &chan->vchan);
1519 
1520 	return 0;
1521 }
1522 
1523 static int stm32_dma3_terminate_all(struct dma_chan *c)
1524 {
1525 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1526 	unsigned long flags;
1527 	LIST_HEAD(head);
1528 
1529 	spin_lock_irqsave(&chan->vchan.lock, flags);
1530 
1531 	if (chan->swdesc) {
1532 		vchan_terminate_vdesc(&chan->swdesc->vdesc);
1533 		chan->swdesc = NULL;
1534 	}
1535 
1536 	stm32_dma3_chan_stop(chan);
1537 
1538 	vchan_get_all_descriptors(&chan->vchan, &head);
1539 
1540 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1541 	vchan_dma_desc_free_list(&chan->vchan, &head);
1542 
1543 	dev_dbg(chan2dev(chan), "vchan %p: terminated\n", &chan->vchan);
1544 
1545 	return 0;
1546 }
1547 
1548 static void stm32_dma3_synchronize(struct dma_chan *c)
1549 {
1550 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1551 
1552 	vchan_synchronize(&chan->vchan);
1553 }
1554 
1555 static enum dma_status stm32_dma3_tx_status(struct dma_chan *c, dma_cookie_t cookie,
1556 					    struct dma_tx_state *txstate)
1557 {
1558 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1559 	struct stm32_dma3_swdesc *swdesc = NULL;
1560 	enum dma_status status;
1561 	unsigned long flags;
1562 	struct virt_dma_desc *vd;
1563 
1564 	status = dma_cookie_status(c, cookie, txstate);
1565 	if (status == DMA_COMPLETE)
1566 		return status;
1567 
1568 	if (!txstate)
1569 		return chan->dma_status;
1570 
1571 	spin_lock_irqsave(&chan->vchan.lock, flags);
1572 
1573 	vd = vchan_find_desc(&chan->vchan, cookie);
1574 	if (vd)
1575 		swdesc = to_stm32_dma3_swdesc(vd);
1576 	else if (chan->swdesc && chan->swdesc->vdesc.tx.cookie == cookie)
1577 		swdesc = chan->swdesc;
1578 
1579 	/* Get residue/in_flight_bytes only if a transfer is currently running (swdesc != NULL) */
1580 	if (swdesc)
1581 		stm32_dma3_chan_set_residue(chan, swdesc, txstate);
1582 
1583 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1584 
1585 	return chan->dma_status;
1586 }
1587 
1588 static void stm32_dma3_issue_pending(struct dma_chan *c)
1589 {
1590 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1591 	unsigned long flags;
1592 
1593 	spin_lock_irqsave(&chan->vchan.lock, flags);
1594 
1595 	if (vchan_issue_pending(&chan->vchan) && !chan->swdesc) {
1596 		dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
1597 		stm32_dma3_chan_start(chan);
1598 	}
1599 
1600 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1601 }
1602 
1603 static bool stm32_dma3_filter_fn(struct dma_chan *c, void *fn_param)
1604 {
1605 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1606 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1607 	struct stm32_dma3_dt_conf *conf = fn_param;
1608 	u32 mask, semcr;
1609 	int ret;
1610 
1611 	dev_dbg(c->device->dev, "%s(%s): req_line=%d ch_conf=%08x tr_conf=%08x\n",
1612 		__func__, dma_chan_name(c), conf->req_line, conf->ch_conf, conf->tr_conf);
1613 
1614 	if (!of_property_read_u32(c->device->dev->of_node, "dma-channel-mask", &mask))
1615 		if (!(mask & BIT(chan->id)))
1616 			return false;
1617 
1618 	ret = pm_runtime_resume_and_get(ddata2dev(ddata));
1619 	if (ret < 0)
1620 		return false;
1621 	semcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id));
1622 	pm_runtime_put_sync(ddata2dev(ddata));
1623 
1624 	/* Check if chan is free */
1625 	if (semcr & CSEMCR_SEM_MUTEX)
1626 		return false;
1627 
1628 	/* Check if chan fifo fits well */
1629 	if (FIELD_GET(STM32_DMA3_DT_FIFO, conf->ch_conf) != chan->fifo_size)
1630 		return false;
1631 
1632 	return true;
1633 }
1634 
1635 static struct dma_chan *stm32_dma3_of_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma)
1636 {
1637 	struct stm32_dma3_ddata *ddata = ofdma->of_dma_data;
1638 	dma_cap_mask_t mask = ddata->dma_dev.cap_mask;
1639 	struct stm32_dma3_dt_conf conf;
1640 	struct stm32_dma3_chan *chan;
1641 	struct dma_chan *c;
1642 
1643 	if (dma_spec->args_count < 3) {
1644 		dev_err(ddata2dev(ddata), "Invalid args count\n");
1645 		return NULL;
1646 	}
1647 
1648 	conf.req_line = dma_spec->args[0];
1649 	conf.ch_conf = dma_spec->args[1];
1650 	conf.tr_conf = dma_spec->args[2];
1651 
1652 	if (conf.req_line >= ddata->dma_requests) {
1653 		dev_err(ddata2dev(ddata), "Invalid request line\n");
1654 		return NULL;
1655 	}
1656 
1657 	/* Request dma channel among the generic dma controller list */
1658 	c = dma_request_channel(mask, stm32_dma3_filter_fn, &conf);
1659 	if (!c) {
1660 		dev_err(ddata2dev(ddata), "No suitable channel found\n");
1661 		return NULL;
1662 	}
1663 
1664 	chan = to_stm32_dma3_chan(c);
1665 	chan->dt_config = conf;
1666 	chan->config_set |= STM32_DMA3_CFG_SET_DT;
1667 
1668 	return c;
1669 }
1670 
1671 static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
1672 {
1673 	struct device *dev = ddata2dev(ddata);
1674 	u32 chan_reserved, mask = 0, i, ccidcfgr, invalid_cid = 0;
1675 
1676 	/* Reserve Secure channels */
1677 	chan_reserved = readl_relaxed(ddata->base + STM32_DMA3_SECCFGR);
1678 
1679 	/*
1680 	 * CID filtering must be configured to ensure that the DMA3 channel will inherit the CID of
1681 	 * the processor which is configuring and using the given channel.
1682 	 * In case CID filtering is not configured, dma-channel-mask property can be used to
1683 	 * specify available DMA channels to the kernel.
1684 	 */
1685 	of_property_read_u32(dev->of_node, "dma-channel-mask", &mask);
1686 
1687 	/* Reserve !CID-filtered not in dma-channel-mask, static CID != CID1, CID1 not allowed */
1688 	for (i = 0; i < ddata->dma_channels; i++) {
1689 		ccidcfgr = readl_relaxed(ddata->base + STM32_DMA3_CCIDCFGR(i));
1690 
1691 		if (!(ccidcfgr & CCIDCFGR_CFEN)) { /* !CID-filtered */
1692 			invalid_cid |= BIT(i);
1693 			if (!(mask & BIT(i))) /* Not in dma-channel-mask */
1694 				chan_reserved |= BIT(i);
1695 		} else { /* CID-filtered */
1696 			if (!(ccidcfgr & CCIDCFGR_SEM_EN)) { /* Static CID mode */
1697 				if (FIELD_GET(CCIDCFGR_SCID, ccidcfgr) != CCIDCFGR_CID1)
1698 					chan_reserved |= BIT(i);
1699 			} else { /* Semaphore mode */
1700 				if (!FIELD_GET(CCIDCFGR_SEM_WLIST_CID1, ccidcfgr))
1701 					chan_reserved |= BIT(i);
1702 				ddata->chans[i].semaphore_mode = true;
1703 			}
1704 		}
1705 		dev_dbg(dev, "chan%d: %s mode, %s\n", i,
1706 			!(ccidcfgr & CCIDCFGR_CFEN) ? "!CID-filtered" :
1707 			ddata->chans[i].semaphore_mode ? "Semaphore" : "Static CID",
1708 			(chan_reserved & BIT(i)) ? "denied" :
1709 			mask & BIT(i) ? "force allowed" : "allowed");
1710 	}
1711 
1712 	if (invalid_cid)
1713 		dev_warn(dev, "chan%*pbl have invalid CID configuration\n",
1714 			 ddata->dma_channels, &invalid_cid);
1715 
1716 	return chan_reserved;
1717 }
1718 
1719 static struct stm32_dma3_pdata stm32mp25_pdata = {
1720 	.axi_max_burst_len = 16,
1721 };
1722 
1723 static const struct of_device_id stm32_dma3_of_match[] = {
1724 	{ .compatible = "st,stm32mp25-dma3", .data = &stm32mp25_pdata, },
1725 	{ /* sentinel */ },
1726 };
1727 MODULE_DEVICE_TABLE(of, stm32_dma3_of_match);
1728 
1729 static int stm32_dma3_probe(struct platform_device *pdev)
1730 {
1731 	struct device_node *np = pdev->dev.of_node;
1732 	const struct stm32_dma3_pdata *pdata;
1733 	struct stm32_dma3_ddata *ddata;
1734 	struct reset_control *reset;
1735 	struct stm32_dma3_chan *chan;
1736 	struct dma_device *dma_dev;
1737 	u32 master_ports, chan_reserved, i, verr;
1738 	u64 hwcfgr;
1739 	int ret;
1740 
1741 	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
1742 	if (!ddata)
1743 		return -ENOMEM;
1744 	platform_set_drvdata(pdev, ddata);
1745 
1746 	dma_dev = &ddata->dma_dev;
1747 
1748 	ddata->base = devm_platform_ioremap_resource(pdev, 0);
1749 	if (IS_ERR(ddata->base))
1750 		return PTR_ERR(ddata->base);
1751 
1752 	ddata->clk = devm_clk_get(&pdev->dev, NULL);
1753 	if (IS_ERR(ddata->clk))
1754 		return dev_err_probe(&pdev->dev, PTR_ERR(ddata->clk), "Failed to get clk\n");
1755 
1756 	reset = devm_reset_control_get_optional(&pdev->dev, NULL);
1757 	if (IS_ERR(reset))
1758 		return dev_err_probe(&pdev->dev, PTR_ERR(reset), "Failed to get reset\n");
1759 
1760 	ret = clk_prepare_enable(ddata->clk);
1761 	if (ret)
1762 		return dev_err_probe(&pdev->dev, ret, "Failed to enable clk\n");
1763 
1764 	reset_control_reset(reset);
1765 
1766 	INIT_LIST_HEAD(&dma_dev->channels);
1767 
1768 	dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
1769 	dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
1770 	dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
1771 	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
1772 	dma_dev->dev = &pdev->dev;
1773 	/*
1774 	 * This controller supports up to 8-byte buswidth depending on the port used and the
1775 	 * channel, and can only access address at even boundaries, multiple of the buswidth.
1776 	 */
1777 	dma_dev->copy_align = DMAENGINE_ALIGN_8_BYTES;
1778 	dma_dev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1779 				   BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1780 				   BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1781 				   BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1782 	dma_dev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1783 				   BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1784 				   BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1785 				   BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1786 	dma_dev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) | BIT(DMA_MEM_TO_MEM);
1787 
1788 	dma_dev->descriptor_reuse = true;
1789 	dma_dev->max_sg_burst = STM32_DMA3_MAX_SEG_SIZE;
1790 	dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1791 	dma_dev->device_alloc_chan_resources = stm32_dma3_alloc_chan_resources;
1792 	dma_dev->device_free_chan_resources = stm32_dma3_free_chan_resources;
1793 	dma_dev->device_prep_dma_memcpy = stm32_dma3_prep_dma_memcpy;
1794 	dma_dev->device_prep_slave_sg = stm32_dma3_prep_slave_sg;
1795 	dma_dev->device_prep_dma_cyclic = stm32_dma3_prep_dma_cyclic;
1796 	dma_dev->device_caps = stm32_dma3_caps;
1797 	dma_dev->device_config = stm32_dma3_config;
1798 	dma_dev->device_pause = stm32_dma3_pause;
1799 	dma_dev->device_resume = stm32_dma3_resume;
1800 	dma_dev->device_terminate_all = stm32_dma3_terminate_all;
1801 	dma_dev->device_synchronize = stm32_dma3_synchronize;
1802 	dma_dev->device_tx_status = stm32_dma3_tx_status;
1803 	dma_dev->device_issue_pending = stm32_dma3_issue_pending;
1804 
1805 	/* if dma_channels is not modified, get it from hwcfgr1 */
1806 	if (of_property_read_u32(np, "dma-channels", &ddata->dma_channels)) {
1807 		hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR1);
1808 		ddata->dma_channels = FIELD_GET(G_NUM_CHANNELS, hwcfgr);
1809 	}
1810 
1811 	/* if dma_requests is not modified, get it from hwcfgr2 */
1812 	if (of_property_read_u32(np, "dma-requests", &ddata->dma_requests)) {
1813 		hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR2);
1814 		ddata->dma_requests = FIELD_GET(G_MAX_REQ_ID, hwcfgr) + 1;
1815 	}
1816 
1817 	/* G_MASTER_PORTS, G_M0_DATA_WIDTH_ENC, G_M1_DATA_WIDTH_ENC in HWCFGR1 */
1818 	hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR1);
1819 	master_ports = FIELD_GET(G_MASTER_PORTS, hwcfgr);
1820 
1821 	ddata->ports_max_dw[0] = FIELD_GET(G_M0_DATA_WIDTH_ENC, hwcfgr);
1822 	if (master_ports == AXI64 || master_ports == AHB32) /* Single master port */
1823 		ddata->ports_max_dw[1] = DW_INVALID;
1824 	else /* Dual master ports */
1825 		ddata->ports_max_dw[1] = FIELD_GET(G_M1_DATA_WIDTH_ENC, hwcfgr);
1826 
1827 	/* axi_max_burst_len is optional, if not defined, use STM32_DMA3_MAX_BURST_LEN  */
1828 	ddata->axi_max_burst_len = STM32_DMA3_MAX_BURST_LEN;
1829 	pdata = device_get_match_data(&pdev->dev);
1830 	if (pdata && pdata->axi_max_burst_len) {
1831 		ddata->axi_max_burst_len = min_t(u32, pdata->axi_max_burst_len,
1832 						 STM32_DMA3_MAX_BURST_LEN);
1833 		dev_dbg(&pdev->dev, "Burst is limited to %u beats through AXI port\n",
1834 			ddata->axi_max_burst_len);
1835 	}
1836 
1837 	ddata->chans = devm_kcalloc(&pdev->dev, ddata->dma_channels, sizeof(*ddata->chans),
1838 				    GFP_KERNEL);
1839 	if (!ddata->chans) {
1840 		ret = -ENOMEM;
1841 		goto err_clk_disable;
1842 	}
1843 
1844 	chan_reserved = stm32_dma3_check_rif(ddata);
1845 
1846 	if (chan_reserved == GENMASK(ddata->dma_channels - 1, 0)) {
1847 		ret = -ENODEV;
1848 		dev_err_probe(&pdev->dev, ret, "No channel available, abort registration\n");
1849 		goto err_clk_disable;
1850 	}
1851 
1852 	/* G_FIFO_SIZE x=0..7 in HWCFGR3 and G_FIFO_SIZE x=8..15 in HWCFGR4 */
1853 	hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR3);
1854 	hwcfgr |= ((u64)readl_relaxed(ddata->base + STM32_DMA3_HWCFGR4)) << 32;
1855 
1856 	for (i = 0; i < ddata->dma_channels; i++) {
1857 		if (chan_reserved & BIT(i))
1858 			continue;
1859 
1860 		chan = &ddata->chans[i];
1861 		chan->id = i;
1862 		chan->fifo_size = get_chan_hwcfg(i, G_FIFO_SIZE(i), hwcfgr);
1863 		/* If chan->fifo_size > 0 then half of the fifo size, else no burst when no FIFO */
1864 		chan->max_burst = (chan->fifo_size) ? (1 << (chan->fifo_size + 1)) / 2 : 0;
1865 	}
1866 
1867 	ret = dmaenginem_async_device_register(dma_dev);
1868 	if (ret)
1869 		goto err_clk_disable;
1870 
1871 	for (i = 0; i < ddata->dma_channels; i++) {
1872 		char name[12];
1873 
1874 		if (chan_reserved & BIT(i))
1875 			continue;
1876 
1877 		chan = &ddata->chans[i];
1878 		snprintf(name, sizeof(name), "dma%dchan%d", ddata->dma_dev.dev_id, chan->id);
1879 
1880 		chan->vchan.desc_free = stm32_dma3_chan_vdesc_free;
1881 		vchan_init(&chan->vchan, dma_dev);
1882 
1883 		ret = dma_async_device_channel_register(&ddata->dma_dev, &chan->vchan.chan, name);
1884 		if (ret) {
1885 			dev_err_probe(&pdev->dev, ret, "Failed to register channel %s\n", name);
1886 			goto err_clk_disable;
1887 		}
1888 
1889 		ret = platform_get_irq(pdev, i);
1890 		if (ret < 0)
1891 			goto err_clk_disable;
1892 		chan->irq = ret;
1893 
1894 		ret = devm_request_irq(&pdev->dev, chan->irq, stm32_dma3_chan_irq, 0,
1895 				       dev_name(chan2dev(chan)), chan);
1896 		if (ret) {
1897 			dev_err_probe(&pdev->dev, ret, "Failed to request channel %s IRQ\n",
1898 				      dev_name(chan2dev(chan)));
1899 			goto err_clk_disable;
1900 		}
1901 	}
1902 
1903 	ret = of_dma_controller_register(np, stm32_dma3_of_xlate, ddata);
1904 	if (ret) {
1905 		dev_err_probe(&pdev->dev, ret, "Failed to register controller\n");
1906 		goto err_clk_disable;
1907 	}
1908 
1909 	verr = readl_relaxed(ddata->base + STM32_DMA3_VERR);
1910 
1911 	pm_runtime_set_active(&pdev->dev);
1912 	pm_runtime_enable(&pdev->dev);
1913 	pm_runtime_get_noresume(&pdev->dev);
1914 	pm_runtime_put(&pdev->dev);
1915 
1916 	dev_info(&pdev->dev, "STM32 DMA3 registered rev:%lu.%lu\n",
1917 		 FIELD_GET(VERR_MAJREV, verr), FIELD_GET(VERR_MINREV, verr));
1918 
1919 	return 0;
1920 
1921 err_clk_disable:
1922 	clk_disable_unprepare(ddata->clk);
1923 
1924 	return ret;
1925 }
1926 
1927 static void stm32_dma3_remove(struct platform_device *pdev)
1928 {
1929 	pm_runtime_disable(&pdev->dev);
1930 }
1931 
1932 static int stm32_dma3_runtime_suspend(struct device *dev)
1933 {
1934 	struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
1935 
1936 	clk_disable_unprepare(ddata->clk);
1937 
1938 	return 0;
1939 }
1940 
1941 static int stm32_dma3_runtime_resume(struct device *dev)
1942 {
1943 	struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
1944 	int ret;
1945 
1946 	ret = clk_prepare_enable(ddata->clk);
1947 	if (ret)
1948 		dev_err(dev, "Failed to enable clk: %d\n", ret);
1949 
1950 	return ret;
1951 }
1952 
1953 static int stm32_dma3_pm_suspend(struct device *dev)
1954 {
1955 	struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
1956 	struct dma_device *dma_dev = &ddata->dma_dev;
1957 	struct dma_chan *c;
1958 	int ccr, ret;
1959 
1960 	ret = pm_runtime_resume_and_get(dev);
1961 	if (ret < 0)
1962 		return ret;
1963 
1964 	list_for_each_entry(c, &dma_dev->channels, device_node) {
1965 		struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1966 
1967 		ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id));
1968 		if (ccr & CCR_EN) {
1969 			dev_warn(dev, "Suspend is prevented: %s still in use by %s\n",
1970 				 dma_chan_name(c), dev_name(c->slave));
1971 			pm_runtime_put_sync(dev);
1972 			return -EBUSY;
1973 		}
1974 	}
1975 
1976 	pm_runtime_put_sync(dev);
1977 
1978 	pm_runtime_force_suspend(dev);
1979 
1980 	return 0;
1981 }
1982 
1983 static int stm32_dma3_pm_resume(struct device *dev)
1984 {
1985 	struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
1986 	struct dma_device *dma_dev = &ddata->dma_dev;
1987 	struct dma_chan *c;
1988 	int ret;
1989 
1990 	ret = pm_runtime_force_resume(dev);
1991 	if (ret < 0)
1992 		return ret;
1993 
1994 	ret = pm_runtime_resume_and_get(dev);
1995 	if (ret < 0)
1996 		return ret;
1997 
1998 	/*
1999 	 * Channel semaphores need to be restored in case of registers reset during low power.
2000 	 * stm32_dma3_get_chan_sem() will prior check the semaphore status.
2001 	 */
2002 	list_for_each_entry(c, &dma_dev->channels, device_node) {
2003 		struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
2004 
2005 		if (chan->semaphore_mode && chan->semaphore_taken)
2006 			stm32_dma3_get_chan_sem(chan);
2007 	}
2008 
2009 	pm_runtime_put_sync(dev);
2010 
2011 	return 0;
2012 }
2013 
2014 static const struct dev_pm_ops stm32_dma3_pm_ops = {
2015 	SYSTEM_SLEEP_PM_OPS(stm32_dma3_pm_suspend, stm32_dma3_pm_resume)
2016 	RUNTIME_PM_OPS(stm32_dma3_runtime_suspend, stm32_dma3_runtime_resume, NULL)
2017 };
2018 
2019 static struct platform_driver stm32_dma3_driver = {
2020 	.probe = stm32_dma3_probe,
2021 	.remove = stm32_dma3_remove,
2022 	.driver = {
2023 		.name = "stm32-dma3",
2024 		.of_match_table = stm32_dma3_of_match,
2025 		.pm = pm_ptr(&stm32_dma3_pm_ops),
2026 	},
2027 };
2028 
2029 module_platform_driver(stm32_dma3_driver);
2030 
2031 MODULE_DESCRIPTION("STM32 DMA3 controller driver");
2032 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@foss.st.com>");
2033 MODULE_LICENSE("GPL");
2034