xref: /linux/drivers/dma/stm32/stm32-dma3.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 	struct stm32_dma3_dt_conf dt_config;
292 	struct dma_slave_config dma_config;
293 	u8 config_set;
294 	struct dma_pool *lli_pool;
295 	struct stm32_dma3_swdesc *swdesc;
296 	enum ctr2_tcem tcem;
297 	u32 dma_status;
298 };
299 
300 struct stm32_dma3_pdata {
301 	u32 axi_max_burst_len;
302 };
303 
304 struct stm32_dma3_ddata {
305 	struct dma_device dma_dev;
306 	void __iomem *base;
307 	struct clk *clk;
308 	struct stm32_dma3_chan *chans;
309 	u32 dma_channels;
310 	u32 dma_requests;
311 	enum stm32_dma3_port_data_width ports_max_dw[2];
312 	u32 axi_max_burst_len;
313 };
314 
315 static inline struct stm32_dma3_ddata *to_stm32_dma3_ddata(struct stm32_dma3_chan *chan)
316 {
317 	return container_of(chan->vchan.chan.device, struct stm32_dma3_ddata, dma_dev);
318 }
319 
320 static inline struct stm32_dma3_chan *to_stm32_dma3_chan(struct dma_chan *c)
321 {
322 	return container_of(c, struct stm32_dma3_chan, vchan.chan);
323 }
324 
325 static inline struct stm32_dma3_swdesc *to_stm32_dma3_swdesc(struct virt_dma_desc *vdesc)
326 {
327 	return container_of(vdesc, struct stm32_dma3_swdesc, vdesc);
328 }
329 
330 static struct device *chan2dev(struct stm32_dma3_chan *chan)
331 {
332 	return &chan->vchan.chan.dev->device;
333 }
334 
335 static void stm32_dma3_chan_dump_reg(struct stm32_dma3_chan *chan)
336 {
337 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
338 	struct device *dev = chan2dev(chan);
339 	u32 id = chan->id, offset;
340 
341 	offset = STM32_DMA3_SECCFGR;
342 	dev_dbg(dev, "SECCFGR(0x%03x): %08x\n", offset, readl_relaxed(ddata->base + offset));
343 	offset = STM32_DMA3_PRIVCFGR;
344 	dev_dbg(dev, "PRIVCFGR(0x%03x): %08x\n", offset, readl_relaxed(ddata->base + offset));
345 	offset = STM32_DMA3_CCIDCFGR(id);
346 	dev_dbg(dev, "C%dCIDCFGR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
347 	offset = STM32_DMA3_CSEMCR(id);
348 	dev_dbg(dev, "C%dSEMCR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
349 	offset = STM32_DMA3_CSR(id);
350 	dev_dbg(dev, "C%dSR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
351 	offset = STM32_DMA3_CCR(id);
352 	dev_dbg(dev, "C%dCR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
353 	offset = STM32_DMA3_CTR1(id);
354 	dev_dbg(dev, "C%dTR1(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
355 	offset = STM32_DMA3_CTR2(id);
356 	dev_dbg(dev, "C%dTR2(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
357 	offset = STM32_DMA3_CBR1(id);
358 	dev_dbg(dev, "C%dBR1(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
359 	offset = STM32_DMA3_CSAR(id);
360 	dev_dbg(dev, "C%dSAR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
361 	offset = STM32_DMA3_CDAR(id);
362 	dev_dbg(dev, "C%dDAR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
363 	offset = STM32_DMA3_CLLR(id);
364 	dev_dbg(dev, "C%dLLR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
365 	offset = STM32_DMA3_CLBAR(id);
366 	dev_dbg(dev, "C%dLBAR(0x%03x): %08x\n", id, offset, readl_relaxed(ddata->base + offset));
367 }
368 
369 static void stm32_dma3_chan_dump_hwdesc(struct stm32_dma3_chan *chan,
370 					struct stm32_dma3_swdesc *swdesc)
371 {
372 	struct stm32_dma3_hwdesc *hwdesc;
373 	int i;
374 
375 	for (i = 0; i < swdesc->lli_size; i++) {
376 		hwdesc = swdesc->lli[i].hwdesc;
377 		if (i)
378 			dev_dbg(chan2dev(chan), "V\n");
379 		dev_dbg(chan2dev(chan), "[%d]@%pad\n", i, &swdesc->lli[i].hwdesc_addr);
380 		dev_dbg(chan2dev(chan), "| C%dTR1: %08x\n", chan->id, hwdesc->ctr1);
381 		dev_dbg(chan2dev(chan), "| C%dTR2: %08x\n", chan->id, hwdesc->ctr2);
382 		dev_dbg(chan2dev(chan), "| C%dBR1: %08x\n", chan->id, hwdesc->cbr1);
383 		dev_dbg(chan2dev(chan), "| C%dSAR: %08x\n", chan->id, hwdesc->csar);
384 		dev_dbg(chan2dev(chan), "| C%dDAR: %08x\n", chan->id, hwdesc->cdar);
385 		dev_dbg(chan2dev(chan), "| C%dLLR: %08x\n", chan->id, hwdesc->cllr);
386 	}
387 
388 	if (swdesc->cyclic) {
389 		dev_dbg(chan2dev(chan), "|\n");
390 		dev_dbg(chan2dev(chan), "-->[0]@%pad\n", &swdesc->lli[0].hwdesc_addr);
391 	} else {
392 		dev_dbg(chan2dev(chan), "X\n");
393 	}
394 }
395 
396 static struct stm32_dma3_swdesc *stm32_dma3_chan_desc_alloc(struct stm32_dma3_chan *chan, u32 count)
397 {
398 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
399 	struct stm32_dma3_swdesc *swdesc;
400 	int i;
401 
402 	/*
403 	 * If the memory to be allocated for the number of hwdesc (6 u32 members but 32-bytes
404 	 * aligned) is greater than the maximum address of CLLR_LA, then the last items can't be
405 	 * addressed, so abort the allocation.
406 	 */
407 	if ((count * 32) > CLLR_LA) {
408 		dev_err(chan2dev(chan), "Transfer is too big (> %luB)\n", STM32_DMA3_MAX_SEG_SIZE);
409 		return NULL;
410 	}
411 
412 	swdesc = kzalloc(struct_size(swdesc, lli, count), GFP_NOWAIT);
413 	if (!swdesc)
414 		return NULL;
415 	swdesc->lli_size = count;
416 
417 	for (i = 0; i < count; i++) {
418 		swdesc->lli[i].hwdesc = dma_pool_zalloc(chan->lli_pool, GFP_NOWAIT,
419 							&swdesc->lli[i].hwdesc_addr);
420 		if (!swdesc->lli[i].hwdesc)
421 			goto err_pool_free;
422 	}
423 	swdesc->ccr = 0;
424 
425 	/* Set LL base address */
426 	writel_relaxed(swdesc->lli[0].hwdesc_addr & CLBAR_LBA,
427 		       ddata->base + STM32_DMA3_CLBAR(chan->id));
428 
429 	/* Set LL allocated port */
430 	swdesc->ccr &= ~CCR_LAP;
431 
432 	return swdesc;
433 
434 err_pool_free:
435 	dev_err(chan2dev(chan), "Failed to alloc descriptors\n");
436 	while (--i >= 0)
437 		dma_pool_free(chan->lli_pool, swdesc->lli[i].hwdesc, swdesc->lli[i].hwdesc_addr);
438 	kfree(swdesc);
439 
440 	return NULL;
441 }
442 
443 static void stm32_dma3_chan_desc_free(struct stm32_dma3_chan *chan,
444 				      struct stm32_dma3_swdesc *swdesc)
445 {
446 	int i;
447 
448 	for (i = 0; i < swdesc->lli_size; i++)
449 		dma_pool_free(chan->lli_pool, swdesc->lli[i].hwdesc, swdesc->lli[i].hwdesc_addr);
450 
451 	kfree(swdesc);
452 }
453 
454 static void stm32_dma3_chan_vdesc_free(struct virt_dma_desc *vdesc)
455 {
456 	struct stm32_dma3_swdesc *swdesc = to_stm32_dma3_swdesc(vdesc);
457 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(vdesc->tx.chan);
458 
459 	stm32_dma3_chan_desc_free(chan, swdesc);
460 }
461 
462 static void stm32_dma3_check_user_setting(struct stm32_dma3_chan *chan)
463 {
464 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
465 	struct device *dev = chan2dev(chan);
466 	u32 ctr1 = readl_relaxed(ddata->base + STM32_DMA3_CTR1(chan->id));
467 	u32 cbr1 = readl_relaxed(ddata->base + STM32_DMA3_CBR1(chan->id));
468 	u32 csar = readl_relaxed(ddata->base + STM32_DMA3_CSAR(chan->id));
469 	u32 cdar = readl_relaxed(ddata->base + STM32_DMA3_CDAR(chan->id));
470 	u32 cllr = readl_relaxed(ddata->base + STM32_DMA3_CLLR(chan->id));
471 	u32 bndt = FIELD_GET(CBR1_BNDT, cbr1);
472 	u32 sdw = 1 << FIELD_GET(CTR1_SDW_LOG2, ctr1);
473 	u32 ddw = 1 << FIELD_GET(CTR1_DDW_LOG2, ctr1);
474 	u32 sap = FIELD_GET(CTR1_SAP, ctr1);
475 	u32 dap = FIELD_GET(CTR1_DAP, ctr1);
476 
477 	if (!bndt && !FIELD_GET(CLLR_UB1, cllr))
478 		dev_err(dev, "null source block size and no update of this value\n");
479 	if (bndt % sdw)
480 		dev_err(dev, "source block size not multiple of src data width\n");
481 	if (FIELD_GET(CTR1_PAM, ctr1) == CTR1_PAM_PACK_UNPACK && bndt % ddw)
482 		dev_err(dev, "(un)packing mode w/ src block size not multiple of dst data width\n");
483 	if (csar % sdw)
484 		dev_err(dev, "unaligned source address not multiple of src data width\n");
485 	if (cdar % ddw)
486 		dev_err(dev, "unaligned destination address not multiple of dst data width\n");
487 	if (sdw == DMA_SLAVE_BUSWIDTH_8_BYTES && port_is_ahb(ddata->ports_max_dw[sap]))
488 		dev_err(dev, "double-word source data width not supported on port %u\n", sap);
489 	if (ddw == DMA_SLAVE_BUSWIDTH_8_BYTES && port_is_ahb(ddata->ports_max_dw[dap]))
490 		dev_err(dev, "double-word destination data width not supported on port %u\n", dap);
491 }
492 
493 static void stm32_dma3_chan_prep_hwdesc(struct stm32_dma3_chan *chan,
494 					struct stm32_dma3_swdesc *swdesc,
495 					u32 curr, dma_addr_t src, dma_addr_t dst, u32 len,
496 					u32 ctr1, u32 ctr2, bool is_last, bool is_cyclic)
497 {
498 	struct stm32_dma3_hwdesc *hwdesc;
499 	dma_addr_t next_lli;
500 	u32 next = curr + 1;
501 
502 	hwdesc = swdesc->lli[curr].hwdesc;
503 	hwdesc->ctr1 = ctr1;
504 	hwdesc->ctr2 = ctr2;
505 	hwdesc->cbr1 = FIELD_PREP(CBR1_BNDT, len);
506 	hwdesc->csar = src;
507 	hwdesc->cdar = dst;
508 
509 	if (is_last) {
510 		if (is_cyclic)
511 			next_lli = swdesc->lli[0].hwdesc_addr;
512 		else
513 			next_lli = 0;
514 	} else {
515 		next_lli = swdesc->lli[next].hwdesc_addr;
516 	}
517 
518 	hwdesc->cllr = 0;
519 	if (next_lli) {
520 		hwdesc->cllr |= CLLR_UT1 | CLLR_UT2 | CLLR_UB1;
521 		hwdesc->cllr |= CLLR_USA | CLLR_UDA | CLLR_ULL;
522 		hwdesc->cllr |= (next_lli & CLLR_LA);
523 	}
524 
525 	/*
526 	 * Make sure to flush the CPU's write buffers so that the descriptors are ready to be read
527 	 * by DMA3. By explicitly using a write memory barrier here, instead of doing it with writel
528 	 * to enable the channel, we avoid an unnecessary barrier in the case where the descriptors
529 	 * are reused (DMA_CTRL_REUSE).
530 	 */
531 	if (is_last)
532 		dma_wmb();
533 }
534 
535 static enum dma_slave_buswidth stm32_dma3_get_max_dw(u32 chan_max_burst,
536 						     enum stm32_dma3_port_data_width port_max_dw,
537 						     u32 len, dma_addr_t addr)
538 {
539 	enum dma_slave_buswidth max_dw = get_chan_max_dw(port_max_dw, chan_max_burst);
540 
541 	/* len and addr must be a multiple of dw */
542 	return 1 << __ffs(len | addr | max_dw);
543 }
544 
545 static u32 stm32_dma3_get_max_burst(u32 len, enum dma_slave_buswidth dw,
546 				    u32 chan_max_burst, u32 bus_max_burst)
547 {
548 	u32 max_burst = chan_max_burst ? chan_max_burst / dw : 1;
549 
550 	/* len is a multiple of dw, so if len is < chan_max_burst, shorten burst */
551 	if (len < chan_max_burst)
552 		max_burst = len / dw;
553 
554 	/*
555 	 * HW doesn't modify the burst if burst size <= half of the fifo size.
556 	 * If len is not a multiple of burst size, last burst is shortened by HW.
557 	 * Take care of maximum burst supported on interconnect bus.
558 	 */
559 	return min_t(u32, max_burst, bus_max_burst);
560 }
561 
562 static int stm32_dma3_chan_prep_hw(struct stm32_dma3_chan *chan, enum dma_transfer_direction dir,
563 				   u32 *ccr, u32 *ctr1, u32 *ctr2,
564 				   dma_addr_t src_addr, dma_addr_t dst_addr, u32 len)
565 {
566 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
567 	struct dma_device dma_device = ddata->dma_dev;
568 	u32 src_max_burst = STM32_DMA3_MAX_BURST_LEN, dst_max_burst = STM32_DMA3_MAX_BURST_LEN;
569 	u32 sdw, ddw, sbl_max, dbl_max, tcem, init_dw, init_bl_max;
570 	u32 _ctr1 = 0, _ctr2 = 0;
571 	u32 ch_conf = chan->dt_config.ch_conf;
572 	u32 tr_conf = chan->dt_config.tr_conf;
573 	u32 sap = FIELD_GET(STM32_DMA3_DT_SAP, tr_conf), sap_max_dw;
574 	u32 dap = FIELD_GET(STM32_DMA3_DT_DAP, tr_conf), dap_max_dw;
575 
576 	dev_dbg(chan2dev(chan), "%s from %pad to %pad\n",
577 		dmaengine_get_direction_text(dir), &src_addr, &dst_addr);
578 
579 	sdw = chan->dma_config.src_addr_width ? : get_chan_max_dw(sap, chan->max_burst);
580 	ddw = chan->dma_config.dst_addr_width ? : get_chan_max_dw(dap, chan->max_burst);
581 	sbl_max = chan->dma_config.src_maxburst ? : 1;
582 	dbl_max = chan->dma_config.dst_maxburst ? : 1;
583 
584 	/* Following conditions would raise User Setting Error interrupt */
585 	if (!(dma_device.src_addr_widths & BIT(sdw)) || !(dma_device.dst_addr_widths & BIT(ddw))) {
586 		dev_err(chan2dev(chan), "Bus width (src=%u, dst=%u) not supported\n", sdw, ddw);
587 		return -EINVAL;
588 	}
589 
590 	if (ddata->ports_max_dw[1] == DW_INVALID && (sap || dap)) {
591 		dev_err(chan2dev(chan), "Only one master port, port 1 is not supported\n");
592 		return -EINVAL;
593 	}
594 
595 	sap_max_dw = ddata->ports_max_dw[sap];
596 	dap_max_dw = ddata->ports_max_dw[dap];
597 	if ((port_is_ahb(sap_max_dw) && sdw == DMA_SLAVE_BUSWIDTH_8_BYTES) ||
598 	    (port_is_ahb(dap_max_dw) && ddw == DMA_SLAVE_BUSWIDTH_8_BYTES)) {
599 		dev_err(chan2dev(chan),
600 			"8 bytes buswidth (src=%u, dst=%u) not supported on port (sap=%u, dap=%u\n",
601 			sdw, ddw, sap, dap);
602 		return -EINVAL;
603 	}
604 
605 	if (FIELD_GET(STM32_DMA3_DT_SINC, tr_conf))
606 		_ctr1 |= CTR1_SINC;
607 	if (sap)
608 		_ctr1 |= CTR1_SAP;
609 	if (port_is_axi(sap_max_dw)) /* AXI - apply axi maximum burst limitation */
610 		src_max_burst = ddata->axi_max_burst_len;
611 	if (FIELD_GET(STM32_DMA3_DT_DINC, tr_conf))
612 		_ctr1 |= CTR1_DINC;
613 	if (dap)
614 		_ctr1 |= CTR1_DAP;
615 	if (port_is_axi(dap_max_dw)) /* AXI - apply axi maximum burst limitation */
616 		dst_max_burst = ddata->axi_max_burst_len;
617 
618 	_ctr2 |= FIELD_PREP(CTR2_REQSEL, chan->dt_config.req_line) & ~CTR2_SWREQ;
619 	if (FIELD_GET(STM32_DMA3_DT_BREQ, tr_conf))
620 		_ctr2 |= CTR2_BREQ;
621 	if (dir == DMA_DEV_TO_MEM && FIELD_GET(STM32_DMA3_DT_PFREQ, tr_conf))
622 		_ctr2 |= CTR2_PFREQ;
623 	tcem = FIELD_GET(STM32_DMA3_DT_TCEM, tr_conf);
624 	_ctr2 |= FIELD_PREP(CTR2_TCEM, tcem);
625 
626 	/* Store TCEM to know on which event TC flag occurred */
627 	chan->tcem = tcem;
628 	/* Store direction for residue computation */
629 	chan->dma_config.direction = dir;
630 
631 	switch (dir) {
632 	case DMA_MEM_TO_DEV:
633 		/* Set destination (device) data width and burst */
634 		ddw = min_t(u32, ddw, stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw,
635 							    len, dst_addr));
636 		dbl_max = min_t(u32, dbl_max, stm32_dma3_get_max_burst(len, ddw, chan->max_burst,
637 								       dst_max_burst));
638 
639 		/* Set source (memory) data width and burst */
640 		sdw = stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr);
641 		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst, src_max_burst);
642 		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf)) {
643 			sdw = ddw;
644 			sbl_max = dbl_max;
645 		}
646 
647 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
648 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);
649 		_ctr1 |= FIELD_PREP(CTR1_DDW_LOG2, ilog2(ddw));
650 		_ctr1 |= FIELD_PREP(CTR1_DBL_1, dbl_max - 1);
651 
652 		if (ddw != sdw) {
653 			_ctr1 |= FIELD_PREP(CTR1_PAM, CTR1_PAM_PACK_UNPACK);
654 			/* Should never reach this case as ddw is clamped down */
655 			if (len & (ddw - 1)) {
656 				dev_err(chan2dev(chan),
657 					"Packing mode is enabled and len is not multiple of ddw");
658 				return -EINVAL;
659 			}
660 		}
661 
662 		/* dst = dev */
663 		_ctr2 |= CTR2_DREQ;
664 
665 		break;
666 
667 	case DMA_DEV_TO_MEM:
668 		/* Set source (device) data width and burst */
669 		sdw = min_t(u32, sdw, stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw,
670 							    len, src_addr));
671 		sbl_max = min_t(u32, sbl_max, stm32_dma3_get_max_burst(len, sdw, chan->max_burst,
672 								       src_max_burst));
673 
674 		/* Set destination (memory) data width and burst */
675 		ddw = stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr);
676 		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst, dst_max_burst);
677 		if (!!FIELD_GET(STM32_DMA3_DT_NOPACK, tr_conf) ||
678 		    ((_ctr2 & CTR2_PFREQ) && ddw > sdw)) { /* Packing to wider ddw not supported */
679 			ddw = sdw;
680 			dbl_max = sbl_max;
681 		}
682 
683 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
684 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);
685 		_ctr1 |= FIELD_PREP(CTR1_DDW_LOG2, ilog2(ddw));
686 		_ctr1 |= FIELD_PREP(CTR1_DBL_1, dbl_max - 1);
687 
688 		if (ddw != sdw) {
689 			_ctr1 |= FIELD_PREP(CTR1_PAM, CTR1_PAM_PACK_UNPACK);
690 			/* Should never reach this case as ddw is clamped down */
691 			if (len & (ddw - 1)) {
692 				dev_err(chan2dev(chan),
693 					"Packing mode is enabled and len is not multiple of ddw\n");
694 				return -EINVAL;
695 			}
696 		}
697 
698 		/* dst = mem */
699 		_ctr2 &= ~CTR2_DREQ;
700 
701 		break;
702 
703 	case DMA_MEM_TO_MEM:
704 		/* Set source (memory) data width and burst */
705 		init_dw = sdw;
706 		init_bl_max = sbl_max;
707 		sdw = stm32_dma3_get_max_dw(chan->max_burst, sap_max_dw, len, src_addr);
708 		sbl_max = stm32_dma3_get_max_burst(len, sdw, chan->max_burst, src_max_burst);
709 		if (chan->config_set & STM32_DMA3_CFG_SET_DMA) {
710 			sdw = min_t(u32, init_dw, sdw);
711 			sbl_max = min_t(u32, init_bl_max, stm32_dma3_get_max_burst(len, sdw,
712 										   chan->max_burst,
713 										   src_max_burst));
714 		}
715 
716 		/* Set destination (memory) data width and burst */
717 		init_dw = ddw;
718 		init_bl_max = dbl_max;
719 		ddw = stm32_dma3_get_max_dw(chan->max_burst, dap_max_dw, len, dst_addr);
720 		dbl_max = stm32_dma3_get_max_burst(len, ddw, chan->max_burst, dst_max_burst);
721 		if (chan->config_set & STM32_DMA3_CFG_SET_DMA) {
722 			ddw = min_t(u32, init_dw, ddw);
723 			dbl_max = min_t(u32, init_bl_max, stm32_dma3_get_max_burst(len, ddw,
724 										   chan->max_burst,
725 										   dst_max_burst));
726 		}
727 
728 		_ctr1 |= FIELD_PREP(CTR1_SDW_LOG2, ilog2(sdw));
729 		_ctr1 |= FIELD_PREP(CTR1_SBL_1, sbl_max - 1);
730 		_ctr1 |= FIELD_PREP(CTR1_DDW_LOG2, ilog2(ddw));
731 		_ctr1 |= FIELD_PREP(CTR1_DBL_1, dbl_max - 1);
732 
733 		if (ddw != sdw) {
734 			_ctr1 |= FIELD_PREP(CTR1_PAM, CTR1_PAM_PACK_UNPACK);
735 			/* Should never reach this case as ddw is clamped down */
736 			if (len & (ddw - 1)) {
737 				dev_err(chan2dev(chan),
738 					"Packing mode is enabled and len is not multiple of ddw");
739 				return -EINVAL;
740 			}
741 		}
742 
743 		/* CTR2_REQSEL/DREQ/BREQ/PFREQ are ignored with CTR2_SWREQ=1 */
744 		_ctr2 |= CTR2_SWREQ;
745 
746 		break;
747 
748 	default:
749 		dev_err(chan2dev(chan), "Direction %s not supported\n",
750 			dmaengine_get_direction_text(dir));
751 		return -EINVAL;
752 	}
753 
754 	*ccr |= FIELD_PREP(CCR_PRIO, FIELD_GET(STM32_DMA3_DT_PRIO, ch_conf));
755 	*ctr1 = _ctr1;
756 	*ctr2 = _ctr2;
757 
758 	dev_dbg(chan2dev(chan), "%s: sdw=%u bytes sbl=%u beats ddw=%u bytes dbl=%u beats\n",
759 		__func__, sdw, sbl_max, ddw, dbl_max);
760 
761 	return 0;
762 }
763 
764 static void stm32_dma3_chan_start(struct stm32_dma3_chan *chan)
765 {
766 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
767 	struct virt_dma_desc *vdesc;
768 	struct stm32_dma3_hwdesc *hwdesc;
769 	u32 id = chan->id;
770 	u32 csr, ccr;
771 
772 	vdesc = vchan_next_desc(&chan->vchan);
773 	if (!vdesc) {
774 		chan->swdesc = NULL;
775 		return;
776 	}
777 	list_del(&vdesc->node);
778 
779 	chan->swdesc = to_stm32_dma3_swdesc(vdesc);
780 	hwdesc = chan->swdesc->lli[0].hwdesc;
781 
782 	stm32_dma3_chan_dump_hwdesc(chan, chan->swdesc);
783 
784 	writel_relaxed(chan->swdesc->ccr, ddata->base + STM32_DMA3_CCR(id));
785 	writel_relaxed(hwdesc->ctr1, ddata->base + STM32_DMA3_CTR1(id));
786 	writel_relaxed(hwdesc->ctr2, ddata->base + STM32_DMA3_CTR2(id));
787 	writel_relaxed(hwdesc->cbr1, ddata->base + STM32_DMA3_CBR1(id));
788 	writel_relaxed(hwdesc->csar, ddata->base + STM32_DMA3_CSAR(id));
789 	writel_relaxed(hwdesc->cdar, ddata->base + STM32_DMA3_CDAR(id));
790 	writel_relaxed(hwdesc->cllr, ddata->base + STM32_DMA3_CLLR(id));
791 
792 	/* Clear any pending interrupts */
793 	csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(id));
794 	if (csr & CSR_ALL_F)
795 		writel_relaxed(csr, ddata->base + STM32_DMA3_CFCR(id));
796 
797 	stm32_dma3_chan_dump_reg(chan);
798 
799 	ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(id));
800 	writel_relaxed(ccr | CCR_EN, ddata->base + STM32_DMA3_CCR(id));
801 
802 	chan->dma_status = DMA_IN_PROGRESS;
803 
804 	dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
805 }
806 
807 static int stm32_dma3_chan_suspend(struct stm32_dma3_chan *chan, bool susp)
808 {
809 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
810 	u32 csr, ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) & ~CCR_EN;
811 	int ret = 0;
812 
813 	if (susp)
814 		ccr |= CCR_SUSP;
815 	else
816 		ccr &= ~CCR_SUSP;
817 
818 	writel_relaxed(ccr, ddata->base + STM32_DMA3_CCR(chan->id));
819 
820 	if (susp) {
821 		ret = readl_relaxed_poll_timeout_atomic(ddata->base + STM32_DMA3_CSR(chan->id), csr,
822 							csr & CSR_SUSPF, 1, 10);
823 		if (!ret)
824 			writel_relaxed(CFCR_SUSPF, ddata->base + STM32_DMA3_CFCR(chan->id));
825 
826 		stm32_dma3_chan_dump_reg(chan);
827 	}
828 
829 	return ret;
830 }
831 
832 static void stm32_dma3_chan_reset(struct stm32_dma3_chan *chan)
833 {
834 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
835 	u32 ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) & ~CCR_EN;
836 
837 	writel_relaxed(ccr |= CCR_RESET, ddata->base + STM32_DMA3_CCR(chan->id));
838 }
839 
840 static int stm32_dma3_chan_get_curr_hwdesc(struct stm32_dma3_swdesc *swdesc, u32 cllr, u32 *residue)
841 {
842 	u32 i, lli_offset, next_lli_offset = cllr & CLLR_LA;
843 
844 	/* If cllr is null, it means it is either the last or single item */
845 	if (!cllr)
846 		return swdesc->lli_size - 1;
847 
848 	/* In cyclic mode, go fast and first check we are not on the last item */
849 	if (swdesc->cyclic && next_lli_offset == (swdesc->lli[0].hwdesc_addr & CLLR_LA))
850 		return swdesc->lli_size - 1;
851 
852 	/* As transfer is in progress, look backward from the last item */
853 	for (i = swdesc->lli_size - 1; i > 0; i--) {
854 		*residue += FIELD_GET(CBR1_BNDT, swdesc->lli[i].hwdesc->cbr1);
855 		lli_offset = swdesc->lli[i].hwdesc_addr & CLLR_LA;
856 		if (lli_offset == next_lli_offset)
857 			return i - 1;
858 	}
859 
860 	return -EINVAL;
861 }
862 
863 static void stm32_dma3_chan_set_residue(struct stm32_dma3_chan *chan,
864 					struct stm32_dma3_swdesc *swdesc,
865 					struct dma_tx_state *txstate)
866 {
867 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
868 	struct device *dev = chan2dev(chan);
869 	struct stm32_dma3_hwdesc *hwdesc;
870 	u32 residue, curr_lli, csr, cdar, cbr1, cllr, bndt, fifol;
871 	bool pack_unpack;
872 	int ret;
873 
874 	csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(chan->id));
875 	if (!(csr & CSR_IDLEF) && chan->dma_status != DMA_PAUSED) {
876 		/* Suspend current transfer to read registers for a snapshot */
877 		writel_relaxed(swdesc->ccr | CCR_SUSP, ddata->base + STM32_DMA3_CCR(chan->id));
878 		ret = readl_relaxed_poll_timeout_atomic(ddata->base + STM32_DMA3_CSR(chan->id), csr,
879 							csr & (CSR_SUSPF | CSR_IDLEF), 1, 10);
880 
881 		if (ret || ((csr & CSR_TCF) && (csr & CSR_IDLEF))) {
882 			writel_relaxed(CFCR_SUSPF, ddata->base + STM32_DMA3_CFCR(chan->id));
883 			writel_relaxed(swdesc->ccr, ddata->base + STM32_DMA3_CCR(chan->id));
884 			if (ret)
885 				dev_err(dev, "Channel suspension timeout, csr=%08x\n", csr);
886 		}
887 	}
888 
889 	/* If channel is still active (CSR_IDLEF is not set), can't get a reliable residue */
890 	if (!(csr & CSR_IDLEF))
891 		dev_warn(dev, "Can't get residue: channel still active, csr=%08x\n", csr);
892 
893 	/*
894 	 * If channel is not suspended, but Idle and Transfer Complete are set,
895 	 * linked-list is over, no residue
896 	 */
897 	if (!(csr & CSR_SUSPF) && (csr & CSR_TCF) && (csr & CSR_IDLEF))
898 		return;
899 
900 	/* Read registers to have a snapshot */
901 	cllr = readl_relaxed(ddata->base + STM32_DMA3_CLLR(chan->id));
902 	cbr1 = readl_relaxed(ddata->base + STM32_DMA3_CBR1(chan->id));
903 	cdar = readl_relaxed(ddata->base + STM32_DMA3_CDAR(chan->id));
904 
905 	/* Resume current transfer */
906 	if (csr & CSR_SUSPF) {
907 		writel_relaxed(CFCR_SUSPF, ddata->base + STM32_DMA3_CFCR(chan->id));
908 		writel_relaxed(swdesc->ccr, ddata->base + STM32_DMA3_CCR(chan->id));
909 	}
910 
911 	/* Add current BNDT */
912 	bndt = FIELD_GET(CBR1_BNDT, cbr1);
913 	residue = bndt;
914 
915 	/* Get current hwdesc and cumulate residue of pending hwdesc BNDT */
916 	ret = stm32_dma3_chan_get_curr_hwdesc(swdesc, cllr, &residue);
917 	if (ret < 0) {
918 		dev_err(chan2dev(chan), "Can't get residue: current hwdesc not found\n");
919 		return;
920 	}
921 	curr_lli = ret;
922 
923 	/* Read current FIFO level - in units of programmed destination data width */
924 	hwdesc = swdesc->lli[curr_lli].hwdesc;
925 	fifol = FIELD_GET(CSR_FIFOL, csr) * (1 << FIELD_GET(CTR1_DDW_LOG2, hwdesc->ctr1));
926 	/* If the FIFO contains as many bytes as its size, it can't contain more */
927 	if (fifol == (1 << (chan->fifo_size + 1)))
928 		goto skip_fifol_update;
929 
930 	/*
931 	 * In case of PACKING (Destination burst length > Source burst length) or UNPACKING
932 	 * (Source burst length > Destination burst length), bytes could be pending in the FIFO
933 	 * (to be packed up to Destination burst length or unpacked into Destination burst length
934 	 * chunks).
935 	 * BNDT is not reliable, as it reflects the number of bytes read from the source but not the
936 	 * number of bytes written to the destination.
937 	 * FIFOL is also not sufficient, because it reflects the number of available write beats in
938 	 * units of Destination data width but not the bytes not yet packed or unpacked.
939 	 * In case of Destination increment DINC, it is possible to compute the number of bytes in
940 	 * the FIFO:
941 	 * fifol_in_bytes = bytes_read - bytes_written.
942 	 */
943 	pack_unpack = !!(FIELD_GET(CTR1_PAM, hwdesc->ctr1) == CTR1_PAM_PACK_UNPACK);
944 	if (pack_unpack && (hwdesc->ctr1 & CTR1_DINC)) {
945 		int bytes_read = FIELD_GET(CBR1_BNDT, hwdesc->cbr1) - bndt;
946 		int bytes_written = cdar - hwdesc->cdar;
947 
948 		if (bytes_read > 0)
949 			fifol = bytes_read - bytes_written;
950 	}
951 
952 skip_fifol_update:
953 	if (fifol) {
954 		dev_dbg(chan2dev(chan), "%u byte(s) in the FIFO\n", fifol);
955 		dma_set_in_flight_bytes(txstate, fifol);
956 		/*
957 		 * Residue is already accurate for DMA_MEM_TO_DEV as BNDT reflects data read from
958 		 * the source memory buffer, so just need to add fifol to residue in case of
959 		 * DMA_DEV_TO_MEM transfer because these bytes are not yet written in destination
960 		 * memory buffer.
961 		 */
962 		if (chan->dma_config.direction == DMA_DEV_TO_MEM)
963 			residue += fifol;
964 	}
965 	dma_set_residue(txstate, residue);
966 }
967 
968 static int stm32_dma3_chan_stop(struct stm32_dma3_chan *chan)
969 {
970 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
971 	u32 ccr;
972 	int ret = 0;
973 
974 	chan->dma_status = DMA_COMPLETE;
975 
976 	/* Disable interrupts */
977 	ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id));
978 	writel_relaxed(ccr & ~(CCR_ALLIE | CCR_EN), ddata->base + STM32_DMA3_CCR(chan->id));
979 
980 	if (!(ccr & CCR_SUSP) && (ccr & CCR_EN)) {
981 		/* Suspend the channel */
982 		ret = stm32_dma3_chan_suspend(chan, true);
983 		if (ret)
984 			dev_warn(chan2dev(chan), "%s: timeout, data might be lost\n", __func__);
985 	}
986 
987 	/*
988 	 * Reset the channel: this causes the reset of the FIFO and the reset of the channel
989 	 * internal state, the reset of CCR_EN and CCR_SUSP bits.
990 	 */
991 	stm32_dma3_chan_reset(chan);
992 
993 	return ret;
994 }
995 
996 static void stm32_dma3_chan_complete(struct stm32_dma3_chan *chan)
997 {
998 	if (!chan->swdesc)
999 		return;
1000 
1001 	vchan_cookie_complete(&chan->swdesc->vdesc);
1002 	chan->swdesc = NULL;
1003 	stm32_dma3_chan_start(chan);
1004 }
1005 
1006 static irqreturn_t stm32_dma3_chan_irq(int irq, void *devid)
1007 {
1008 	struct stm32_dma3_chan *chan = devid;
1009 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1010 	u32 misr, csr, ccr;
1011 
1012 	spin_lock(&chan->vchan.lock);
1013 
1014 	misr = readl_relaxed(ddata->base + STM32_DMA3_MISR);
1015 	if (!(misr & MISR_MIS(chan->id))) {
1016 		spin_unlock(&chan->vchan.lock);
1017 		return IRQ_NONE;
1018 	}
1019 
1020 	csr = readl_relaxed(ddata->base + STM32_DMA3_CSR(chan->id));
1021 	ccr = readl_relaxed(ddata->base + STM32_DMA3_CCR(chan->id)) & CCR_ALLIE;
1022 
1023 	if (csr & CSR_TCF && ccr & CCR_TCIE) {
1024 		if (chan->swdesc->cyclic)
1025 			vchan_cyclic_callback(&chan->swdesc->vdesc);
1026 		else
1027 			stm32_dma3_chan_complete(chan);
1028 	}
1029 
1030 	if (csr & CSR_USEF && ccr & CCR_USEIE) {
1031 		dev_err(chan2dev(chan), "User setting error\n");
1032 		chan->dma_status = DMA_ERROR;
1033 		/* CCR.EN automatically cleared by HW */
1034 		stm32_dma3_check_user_setting(chan);
1035 		stm32_dma3_chan_reset(chan);
1036 	}
1037 
1038 	if (csr & CSR_ULEF && ccr & CCR_ULEIE) {
1039 		dev_err(chan2dev(chan), "Update link transfer error\n");
1040 		chan->dma_status = DMA_ERROR;
1041 		/* CCR.EN automatically cleared by HW */
1042 		stm32_dma3_chan_reset(chan);
1043 	}
1044 
1045 	if (csr & CSR_DTEF && ccr & CCR_DTEIE) {
1046 		dev_err(chan2dev(chan), "Data transfer error\n");
1047 		chan->dma_status = DMA_ERROR;
1048 		/* CCR.EN automatically cleared by HW */
1049 		stm32_dma3_chan_reset(chan);
1050 	}
1051 
1052 	/*
1053 	 * Half Transfer Interrupt may be disabled but Half Transfer Flag can be set,
1054 	 * ensure HTF flag to be cleared, with other flags.
1055 	 */
1056 	csr &= (ccr | CCR_HTIE);
1057 
1058 	if (csr)
1059 		writel_relaxed(csr, ddata->base + STM32_DMA3_CFCR(chan->id));
1060 
1061 	spin_unlock(&chan->vchan.lock);
1062 
1063 	return IRQ_HANDLED;
1064 }
1065 
1066 static int stm32_dma3_alloc_chan_resources(struct dma_chan *c)
1067 {
1068 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1069 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1070 	u32 id = chan->id, csemcr, ccid;
1071 	int ret;
1072 
1073 	ret = pm_runtime_resume_and_get(ddata->dma_dev.dev);
1074 	if (ret < 0)
1075 		return ret;
1076 
1077 	/* Ensure the channel is free */
1078 	if (chan->semaphore_mode &&
1079 	    readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id)) & CSEMCR_SEM_MUTEX) {
1080 		ret = -EBUSY;
1081 		goto err_put_sync;
1082 	}
1083 
1084 	chan->lli_pool = dmam_pool_create(dev_name(&c->dev->device), c->device->dev,
1085 					  sizeof(struct stm32_dma3_hwdesc),
1086 					  __alignof__(struct stm32_dma3_hwdesc), SZ_64K);
1087 	if (!chan->lli_pool) {
1088 		dev_err(chan2dev(chan), "Failed to create LLI pool\n");
1089 		ret = -ENOMEM;
1090 		goto err_put_sync;
1091 	}
1092 
1093 	/* Take the channel semaphore */
1094 	if (chan->semaphore_mode) {
1095 		writel_relaxed(CSEMCR_SEM_MUTEX, ddata->base + STM32_DMA3_CSEMCR(id));
1096 		csemcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(id));
1097 		ccid = FIELD_GET(CSEMCR_SEM_CCID, csemcr);
1098 		/* Check that the channel is well taken */
1099 		if (ccid != CCIDCFGR_CID1) {
1100 			dev_err(chan2dev(chan), "Not under CID1 control (in-use by CID%d)\n", ccid);
1101 			ret = -EPERM;
1102 			goto err_pool_destroy;
1103 		}
1104 		dev_dbg(chan2dev(chan), "Under CID1 control (semcr=0x%08x)\n", csemcr);
1105 	}
1106 
1107 	return 0;
1108 
1109 err_pool_destroy:
1110 	dmam_pool_destroy(chan->lli_pool);
1111 	chan->lli_pool = NULL;
1112 
1113 err_put_sync:
1114 	pm_runtime_put_sync(ddata->dma_dev.dev);
1115 
1116 	return ret;
1117 }
1118 
1119 static void stm32_dma3_free_chan_resources(struct dma_chan *c)
1120 {
1121 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1122 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1123 	unsigned long flags;
1124 
1125 	/* Ensure channel is in idle state */
1126 	spin_lock_irqsave(&chan->vchan.lock, flags);
1127 	stm32_dma3_chan_stop(chan);
1128 	chan->swdesc = NULL;
1129 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1130 
1131 	vchan_free_chan_resources(to_virt_chan(c));
1132 
1133 	dmam_pool_destroy(chan->lli_pool);
1134 	chan->lli_pool = NULL;
1135 
1136 	/* Release the channel semaphore */
1137 	if (chan->semaphore_mode)
1138 		writel_relaxed(0, ddata->base + STM32_DMA3_CSEMCR(chan->id));
1139 
1140 	pm_runtime_put_sync(ddata->dma_dev.dev);
1141 
1142 	/* Reset configuration */
1143 	memset(&chan->dt_config, 0, sizeof(chan->dt_config));
1144 	memset(&chan->dma_config, 0, sizeof(chan->dma_config));
1145 	chan->config_set = 0;
1146 }
1147 
1148 static u32 stm32_dma3_get_ll_count(struct stm32_dma3_chan *chan, size_t len, bool prevent_refactor)
1149 {
1150 	u32 count;
1151 
1152 	if (prevent_refactor)
1153 		return DIV_ROUND_UP(len, STM32_DMA3_MAX_BLOCK_SIZE);
1154 
1155 	count = len / STM32_DMA3_MAX_BLOCK_SIZE;
1156 	len -= (len / STM32_DMA3_MAX_BLOCK_SIZE) * STM32_DMA3_MAX_BLOCK_SIZE;
1157 
1158 	if (len >= chan->max_burst) {
1159 		count += 1; /* len < STM32_DMA3_MAX_BLOCK_SIZE here, so it fits in one item */
1160 		len -= (len / chan->max_burst) * chan->max_burst;
1161 	}
1162 
1163 	/* Unaligned remainder fits in one extra item */
1164 	if (len > 0)
1165 		count += 1;
1166 
1167 	return count;
1168 }
1169 
1170 static void stm32_dma3_init_chan_config_for_memcpy(struct stm32_dma3_chan *chan,
1171 						   dma_addr_t dst, dma_addr_t src)
1172 {
1173 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1174 	u32 dw = get_chan_max_dw(ddata->ports_max_dw[0], chan->max_burst); /* port 0 by default */
1175 	u32 burst = chan->max_burst / dw;
1176 
1177 	/* Initialize dt_config if channel not pre-configured through DT */
1178 	if (!(chan->config_set & STM32_DMA3_CFG_SET_DT)) {
1179 		chan->dt_config.ch_conf = FIELD_PREP(STM32_DMA3_DT_PRIO, CCR_PRIO_VERY_HIGH);
1180 		chan->dt_config.ch_conf |= FIELD_PREP(STM32_DMA3_DT_FIFO, chan->fifo_size);
1181 		chan->dt_config.tr_conf = STM32_DMA3_DT_SINC | STM32_DMA3_DT_DINC;
1182 		chan->dt_config.tr_conf |= FIELD_PREP(STM32_DMA3_DT_TCEM, CTR2_TCEM_CHANNEL);
1183 	}
1184 
1185 	/* Initialize dma_config if dmaengine_slave_config() not used */
1186 	if (!(chan->config_set & STM32_DMA3_CFG_SET_DMA)) {
1187 		chan->dma_config.src_addr_width = dw;
1188 		chan->dma_config.dst_addr_width = dw;
1189 		chan->dma_config.src_maxburst = burst;
1190 		chan->dma_config.dst_maxburst = burst;
1191 		chan->dma_config.src_addr = src;
1192 		chan->dma_config.dst_addr = dst;
1193 	}
1194 }
1195 
1196 static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_memcpy(struct dma_chan *c,
1197 								  dma_addr_t dst, dma_addr_t src,
1198 								  size_t len, unsigned long flags)
1199 {
1200 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1201 	struct stm32_dma3_swdesc *swdesc;
1202 	size_t next_size, offset;
1203 	u32 count, i, ctr1, ctr2;
1204 	bool prevent_refactor = !!FIELD_GET(STM32_DMA3_DT_NOPACK, chan->dt_config.tr_conf) ||
1205 				!!FIELD_GET(STM32_DMA3_DT_NOREFACT, chan->dt_config.tr_conf);
1206 
1207 	count = stm32_dma3_get_ll_count(chan, len, prevent_refactor);
1208 
1209 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
1210 	if (!swdesc)
1211 		return NULL;
1212 
1213 	if (chan->config_set != STM32_DMA3_CFG_SET_BOTH)
1214 		stm32_dma3_init_chan_config_for_memcpy(chan, dst, src);
1215 
1216 	for (i = 0, offset = 0; offset < len; i++, offset += next_size) {
1217 		size_t remaining;
1218 		int ret;
1219 
1220 		remaining = len - offset;
1221 		next_size = min_t(size_t, remaining, STM32_DMA3_MAX_BLOCK_SIZE);
1222 
1223 		if (!prevent_refactor &&
1224 		    (next_size < STM32_DMA3_MAX_BLOCK_SIZE && next_size >= chan->max_burst))
1225 			next_size = chan->max_burst * (remaining / chan->max_burst);
1226 
1227 		ret = stm32_dma3_chan_prep_hw(chan, DMA_MEM_TO_MEM, &swdesc->ccr, &ctr1, &ctr2,
1228 					      src + offset, dst + offset, next_size);
1229 		if (ret)
1230 			goto err_desc_free;
1231 
1232 		stm32_dma3_chan_prep_hwdesc(chan, swdesc, i, src + offset, dst + offset, next_size,
1233 					    ctr1, ctr2, next_size == remaining, false);
1234 	}
1235 
1236 	/* Enable Errors interrupts */
1237 	swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
1238 	/* Enable Transfer state interrupts */
1239 	swdesc->ccr |= CCR_TCIE;
1240 
1241 	swdesc->cyclic = false;
1242 
1243 	return vchan_tx_prep(&chan->vchan, &swdesc->vdesc, flags);
1244 
1245 err_desc_free:
1246 	stm32_dma3_chan_desc_free(chan, swdesc);
1247 
1248 	return NULL;
1249 }
1250 
1251 static struct dma_async_tx_descriptor *stm32_dma3_prep_slave_sg(struct dma_chan *c,
1252 								struct scatterlist *sgl,
1253 								unsigned int sg_len,
1254 								enum dma_transfer_direction dir,
1255 								unsigned long flags, void *context)
1256 {
1257 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1258 	struct stm32_dma3_swdesc *swdesc;
1259 	struct scatterlist *sg;
1260 	size_t len;
1261 	dma_addr_t sg_addr, dev_addr, src, dst;
1262 	u32 i, j, count, ctr1, ctr2;
1263 	bool prevent_refactor = !!FIELD_GET(STM32_DMA3_DT_NOPACK, chan->dt_config.tr_conf) ||
1264 				!!FIELD_GET(STM32_DMA3_DT_NOREFACT, chan->dt_config.tr_conf);
1265 	int ret;
1266 
1267 	count = 0;
1268 	for_each_sg(sgl, sg, sg_len, i)
1269 		count += stm32_dma3_get_ll_count(chan, sg_dma_len(sg), prevent_refactor);
1270 
1271 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
1272 	if (!swdesc)
1273 		return NULL;
1274 
1275 	/* sg_len and i correspond to the initial sgl; count and j correspond to the hwdesc LL */
1276 	j = 0;
1277 	for_each_sg(sgl, sg, sg_len, i) {
1278 		sg_addr = sg_dma_address(sg);
1279 		dev_addr = (dir == DMA_MEM_TO_DEV) ? chan->dma_config.dst_addr :
1280 						     chan->dma_config.src_addr;
1281 		len = sg_dma_len(sg);
1282 
1283 		do {
1284 			size_t chunk = min_t(size_t, len, STM32_DMA3_MAX_BLOCK_SIZE);
1285 
1286 			if (!prevent_refactor &&
1287 			    (chunk < STM32_DMA3_MAX_BLOCK_SIZE && chunk >= chan->max_burst))
1288 				chunk = chan->max_burst * (len / chan->max_burst);
1289 
1290 			if (dir == DMA_MEM_TO_DEV) {
1291 				src = sg_addr;
1292 				dst = dev_addr;
1293 
1294 				ret = stm32_dma3_chan_prep_hw(chan, dir, &swdesc->ccr, &ctr1, &ctr2,
1295 							      src, dst, chunk);
1296 
1297 				if (FIELD_GET(CTR1_DINC, ctr1))
1298 					dev_addr += chunk;
1299 			} else { /* (dir == DMA_DEV_TO_MEM || dir == DMA_MEM_TO_MEM) */
1300 				src = dev_addr;
1301 				dst = sg_addr;
1302 
1303 				ret = stm32_dma3_chan_prep_hw(chan, dir, &swdesc->ccr, &ctr1, &ctr2,
1304 							      src, dst, chunk);
1305 
1306 				if (FIELD_GET(CTR1_SINC, ctr1))
1307 					dev_addr += chunk;
1308 			}
1309 
1310 			if (ret)
1311 				goto err_desc_free;
1312 
1313 			stm32_dma3_chan_prep_hwdesc(chan, swdesc, j, src, dst, chunk,
1314 						    ctr1, ctr2, j == (count - 1), false);
1315 
1316 			sg_addr += chunk;
1317 			len -= chunk;
1318 			j++;
1319 		} while (len);
1320 	}
1321 
1322 	if (count != sg_len && chan->tcem != CTR2_TCEM_CHANNEL)
1323 		dev_warn(chan2dev(chan), "Linked-list refactored, %d items instead of %d\n",
1324 			 count, sg_len);
1325 
1326 	/* Enable Error interrupts */
1327 	swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
1328 	/* Enable Transfer state interrupts */
1329 	swdesc->ccr |= CCR_TCIE;
1330 
1331 	swdesc->cyclic = false;
1332 
1333 	return vchan_tx_prep(&chan->vchan, &swdesc->vdesc, flags);
1334 
1335 err_desc_free:
1336 	stm32_dma3_chan_desc_free(chan, swdesc);
1337 
1338 	return NULL;
1339 }
1340 
1341 static struct dma_async_tx_descriptor *stm32_dma3_prep_dma_cyclic(struct dma_chan *c,
1342 								  dma_addr_t buf_addr,
1343 								  size_t buf_len, size_t period_len,
1344 								  enum dma_transfer_direction dir,
1345 								  unsigned long flags)
1346 {
1347 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1348 	struct stm32_dma3_swdesc *swdesc;
1349 	dma_addr_t src, dst;
1350 	u32 count, i, ctr1, ctr2;
1351 	int ret;
1352 
1353 	if (!buf_len || !period_len || period_len > STM32_DMA3_MAX_BLOCK_SIZE) {
1354 		dev_err(chan2dev(chan), "Invalid buffer/period length\n");
1355 		return NULL;
1356 	}
1357 
1358 	if (buf_len % period_len) {
1359 		dev_err(chan2dev(chan), "Buffer length not multiple of period length\n");
1360 		return NULL;
1361 	}
1362 
1363 	count = buf_len / period_len;
1364 	swdesc = stm32_dma3_chan_desc_alloc(chan, count);
1365 	if (!swdesc)
1366 		return NULL;
1367 
1368 	if (dir == DMA_MEM_TO_DEV) {
1369 		src = buf_addr;
1370 		dst = chan->dma_config.dst_addr;
1371 
1372 		ret = stm32_dma3_chan_prep_hw(chan, DMA_MEM_TO_DEV, &swdesc->ccr, &ctr1, &ctr2,
1373 					      src, dst, period_len);
1374 	} else if (dir == DMA_DEV_TO_MEM) {
1375 		src = chan->dma_config.src_addr;
1376 		dst = buf_addr;
1377 
1378 		ret = stm32_dma3_chan_prep_hw(chan, DMA_DEV_TO_MEM, &swdesc->ccr, &ctr1, &ctr2,
1379 					      src, dst, period_len);
1380 	} else {
1381 		dev_err(chan2dev(chan), "Invalid direction\n");
1382 		ret = -EINVAL;
1383 	}
1384 
1385 	if (ret)
1386 		goto err_desc_free;
1387 
1388 	for (i = 0; i < count; i++) {
1389 		if (dir == DMA_MEM_TO_DEV) {
1390 			src = buf_addr + i * period_len;
1391 			dst = chan->dma_config.dst_addr;
1392 		} else { /* (dir == DMA_DEV_TO_MEM) */
1393 			src = chan->dma_config.src_addr;
1394 			dst = buf_addr + i * period_len;
1395 		}
1396 
1397 		stm32_dma3_chan_prep_hwdesc(chan, swdesc, i, src, dst, period_len,
1398 					    ctr1, ctr2, i == (count - 1), true);
1399 	}
1400 
1401 	/* Enable Error interrupts */
1402 	swdesc->ccr |= CCR_USEIE | CCR_ULEIE | CCR_DTEIE;
1403 	/* Enable Transfer state interrupts */
1404 	swdesc->ccr |= CCR_TCIE;
1405 
1406 	swdesc->cyclic = true;
1407 
1408 	return vchan_tx_prep(&chan->vchan, &swdesc->vdesc, flags);
1409 
1410 err_desc_free:
1411 	stm32_dma3_chan_desc_free(chan, swdesc);
1412 
1413 	return NULL;
1414 }
1415 
1416 static void stm32_dma3_caps(struct dma_chan *c, struct dma_slave_caps *caps)
1417 {
1418 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1419 
1420 	if (!chan->fifo_size) {
1421 		caps->max_burst = 0;
1422 		caps->src_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1423 		caps->dst_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1424 	} else {
1425 		/* Burst transfer should not exceed half of the fifo size */
1426 		caps->max_burst = chan->max_burst;
1427 		if (caps->max_burst < DMA_SLAVE_BUSWIDTH_8_BYTES) {
1428 			caps->src_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1429 			caps->dst_addr_widths &= ~BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1430 		}
1431 	}
1432 }
1433 
1434 static int stm32_dma3_config(struct dma_chan *c, struct dma_slave_config *config)
1435 {
1436 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1437 
1438 	memcpy(&chan->dma_config, config, sizeof(*config));
1439 	chan->config_set |= STM32_DMA3_CFG_SET_DMA;
1440 
1441 	return 0;
1442 }
1443 
1444 static int stm32_dma3_pause(struct dma_chan *c)
1445 {
1446 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1447 	int ret;
1448 
1449 	ret = stm32_dma3_chan_suspend(chan, true);
1450 	if (ret)
1451 		return ret;
1452 
1453 	chan->dma_status = DMA_PAUSED;
1454 
1455 	dev_dbg(chan2dev(chan), "vchan %pK: paused\n", &chan->vchan);
1456 
1457 	return 0;
1458 }
1459 
1460 static int stm32_dma3_resume(struct dma_chan *c)
1461 {
1462 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1463 
1464 	stm32_dma3_chan_suspend(chan, false);
1465 
1466 	chan->dma_status = DMA_IN_PROGRESS;
1467 
1468 	dev_dbg(chan2dev(chan), "vchan %pK: resumed\n", &chan->vchan);
1469 
1470 	return 0;
1471 }
1472 
1473 static int stm32_dma3_terminate_all(struct dma_chan *c)
1474 {
1475 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1476 	unsigned long flags;
1477 	LIST_HEAD(head);
1478 
1479 	spin_lock_irqsave(&chan->vchan.lock, flags);
1480 
1481 	if (chan->swdesc) {
1482 		vchan_terminate_vdesc(&chan->swdesc->vdesc);
1483 		chan->swdesc = NULL;
1484 	}
1485 
1486 	stm32_dma3_chan_stop(chan);
1487 
1488 	vchan_get_all_descriptors(&chan->vchan, &head);
1489 
1490 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1491 	vchan_dma_desc_free_list(&chan->vchan, &head);
1492 
1493 	dev_dbg(chan2dev(chan), "vchan %pK: terminated\n", &chan->vchan);
1494 
1495 	return 0;
1496 }
1497 
1498 static void stm32_dma3_synchronize(struct dma_chan *c)
1499 {
1500 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1501 
1502 	vchan_synchronize(&chan->vchan);
1503 }
1504 
1505 static enum dma_status stm32_dma3_tx_status(struct dma_chan *c, dma_cookie_t cookie,
1506 					    struct dma_tx_state *txstate)
1507 {
1508 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1509 	struct stm32_dma3_swdesc *swdesc = NULL;
1510 	enum dma_status status;
1511 	unsigned long flags;
1512 	struct virt_dma_desc *vd;
1513 
1514 	status = dma_cookie_status(c, cookie, txstate);
1515 	if (status == DMA_COMPLETE)
1516 		return status;
1517 
1518 	if (!txstate)
1519 		return chan->dma_status;
1520 
1521 	spin_lock_irqsave(&chan->vchan.lock, flags);
1522 
1523 	vd = vchan_find_desc(&chan->vchan, cookie);
1524 	if (vd)
1525 		swdesc = to_stm32_dma3_swdesc(vd);
1526 	else if (chan->swdesc && chan->swdesc->vdesc.tx.cookie == cookie)
1527 		swdesc = chan->swdesc;
1528 
1529 	/* Get residue/in_flight_bytes only if a transfer is currently running (swdesc != NULL) */
1530 	if (swdesc)
1531 		stm32_dma3_chan_set_residue(chan, swdesc, txstate);
1532 
1533 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1534 
1535 	return chan->dma_status;
1536 }
1537 
1538 static void stm32_dma3_issue_pending(struct dma_chan *c)
1539 {
1540 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1541 	unsigned long flags;
1542 
1543 	spin_lock_irqsave(&chan->vchan.lock, flags);
1544 
1545 	if (vchan_issue_pending(&chan->vchan) && !chan->swdesc) {
1546 		dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
1547 		stm32_dma3_chan_start(chan);
1548 	}
1549 
1550 	spin_unlock_irqrestore(&chan->vchan.lock, flags);
1551 }
1552 
1553 static bool stm32_dma3_filter_fn(struct dma_chan *c, void *fn_param)
1554 {
1555 	struct stm32_dma3_chan *chan = to_stm32_dma3_chan(c);
1556 	struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
1557 	struct stm32_dma3_dt_conf *conf = fn_param;
1558 	u32 mask, semcr;
1559 	int ret;
1560 
1561 	dev_dbg(c->device->dev, "%s(%s): req_line=%d ch_conf=%08x tr_conf=%08x\n",
1562 		__func__, dma_chan_name(c), conf->req_line, conf->ch_conf, conf->tr_conf);
1563 
1564 	if (!of_property_read_u32(c->device->dev->of_node, "dma-channel-mask", &mask))
1565 		if (!(mask & BIT(chan->id)))
1566 			return false;
1567 
1568 	ret = pm_runtime_resume_and_get(ddata->dma_dev.dev);
1569 	if (ret < 0)
1570 		return false;
1571 	semcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id));
1572 	pm_runtime_put_sync(ddata->dma_dev.dev);
1573 
1574 	/* Check if chan is free */
1575 	if (semcr & CSEMCR_SEM_MUTEX)
1576 		return false;
1577 
1578 	/* Check if chan fifo fits well */
1579 	if (FIELD_GET(STM32_DMA3_DT_FIFO, conf->ch_conf) != chan->fifo_size)
1580 		return false;
1581 
1582 	return true;
1583 }
1584 
1585 static struct dma_chan *stm32_dma3_of_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma)
1586 {
1587 	struct stm32_dma3_ddata *ddata = ofdma->of_dma_data;
1588 	dma_cap_mask_t mask = ddata->dma_dev.cap_mask;
1589 	struct stm32_dma3_dt_conf conf;
1590 	struct stm32_dma3_chan *chan;
1591 	struct dma_chan *c;
1592 
1593 	if (dma_spec->args_count < 3) {
1594 		dev_err(ddata->dma_dev.dev, "Invalid args count\n");
1595 		return NULL;
1596 	}
1597 
1598 	conf.req_line = dma_spec->args[0];
1599 	conf.ch_conf = dma_spec->args[1];
1600 	conf.tr_conf = dma_spec->args[2];
1601 
1602 	if (conf.req_line >= ddata->dma_requests) {
1603 		dev_err(ddata->dma_dev.dev, "Invalid request line\n");
1604 		return NULL;
1605 	}
1606 
1607 	/* Request dma channel among the generic dma controller list */
1608 	c = dma_request_channel(mask, stm32_dma3_filter_fn, &conf);
1609 	if (!c) {
1610 		dev_err(ddata->dma_dev.dev, "No suitable channel found\n");
1611 		return NULL;
1612 	}
1613 
1614 	chan = to_stm32_dma3_chan(c);
1615 	chan->dt_config = conf;
1616 	chan->config_set |= STM32_DMA3_CFG_SET_DT;
1617 
1618 	return c;
1619 }
1620 
1621 static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
1622 {
1623 	u32 chan_reserved, mask = 0, i, ccidcfgr, invalid_cid = 0;
1624 
1625 	/* Reserve Secure channels */
1626 	chan_reserved = readl_relaxed(ddata->base + STM32_DMA3_SECCFGR);
1627 
1628 	/*
1629 	 * CID filtering must be configured to ensure that the DMA3 channel will inherit the CID of
1630 	 * the processor which is configuring and using the given channel.
1631 	 * In case CID filtering is not configured, dma-channel-mask property can be used to
1632 	 * specify available DMA channels to the kernel.
1633 	 */
1634 	of_property_read_u32(ddata->dma_dev.dev->of_node, "dma-channel-mask", &mask);
1635 
1636 	/* Reserve !CID-filtered not in dma-channel-mask, static CID != CID1, CID1 not allowed */
1637 	for (i = 0; i < ddata->dma_channels; i++) {
1638 		ccidcfgr = readl_relaxed(ddata->base + STM32_DMA3_CCIDCFGR(i));
1639 
1640 		if (!(ccidcfgr & CCIDCFGR_CFEN)) { /* !CID-filtered */
1641 			invalid_cid |= BIT(i);
1642 			if (!(mask & BIT(i))) /* Not in dma-channel-mask */
1643 				chan_reserved |= BIT(i);
1644 		} else { /* CID-filtered */
1645 			if (!(ccidcfgr & CCIDCFGR_SEM_EN)) { /* Static CID mode */
1646 				if (FIELD_GET(CCIDCFGR_SCID, ccidcfgr) != CCIDCFGR_CID1)
1647 					chan_reserved |= BIT(i);
1648 			} else { /* Semaphore mode */
1649 				if (!FIELD_GET(CCIDCFGR_SEM_WLIST_CID1, ccidcfgr))
1650 					chan_reserved |= BIT(i);
1651 				ddata->chans[i].semaphore_mode = true;
1652 			}
1653 		}
1654 		dev_dbg(ddata->dma_dev.dev, "chan%d: %s mode, %s\n", i,
1655 			!(ccidcfgr & CCIDCFGR_CFEN) ? "!CID-filtered" :
1656 			ddata->chans[i].semaphore_mode ? "Semaphore" : "Static CID",
1657 			(chan_reserved & BIT(i)) ? "denied" :
1658 			mask & BIT(i) ? "force allowed" : "allowed");
1659 	}
1660 
1661 	if (invalid_cid)
1662 		dev_warn(ddata->dma_dev.dev, "chan%*pbl have invalid CID configuration\n",
1663 			 ddata->dma_channels, &invalid_cid);
1664 
1665 	return chan_reserved;
1666 }
1667 
1668 static struct stm32_dma3_pdata stm32mp25_pdata = {
1669 	.axi_max_burst_len = 16,
1670 };
1671 
1672 static const struct of_device_id stm32_dma3_of_match[] = {
1673 	{ .compatible = "st,stm32mp25-dma3", .data = &stm32mp25_pdata, },
1674 	{ /* sentinel */ },
1675 };
1676 MODULE_DEVICE_TABLE(of, stm32_dma3_of_match);
1677 
1678 static int stm32_dma3_probe(struct platform_device *pdev)
1679 {
1680 	struct device_node *np = pdev->dev.of_node;
1681 	const struct stm32_dma3_pdata *pdata;
1682 	struct stm32_dma3_ddata *ddata;
1683 	struct reset_control *reset;
1684 	struct stm32_dma3_chan *chan;
1685 	struct dma_device *dma_dev;
1686 	u32 master_ports, chan_reserved, i, verr;
1687 	u64 hwcfgr;
1688 	int ret;
1689 
1690 	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
1691 	if (!ddata)
1692 		return -ENOMEM;
1693 	platform_set_drvdata(pdev, ddata);
1694 
1695 	dma_dev = &ddata->dma_dev;
1696 
1697 	ddata->base = devm_platform_ioremap_resource(pdev, 0);
1698 	if (IS_ERR(ddata->base))
1699 		return PTR_ERR(ddata->base);
1700 
1701 	ddata->clk = devm_clk_get(&pdev->dev, NULL);
1702 	if (IS_ERR(ddata->clk))
1703 		return dev_err_probe(&pdev->dev, PTR_ERR(ddata->clk), "Failed to get clk\n");
1704 
1705 	reset = devm_reset_control_get_optional(&pdev->dev, NULL);
1706 	if (IS_ERR(reset))
1707 		return dev_err_probe(&pdev->dev, PTR_ERR(reset), "Failed to get reset\n");
1708 
1709 	ret = clk_prepare_enable(ddata->clk);
1710 	if (ret)
1711 		return dev_err_probe(&pdev->dev, ret, "Failed to enable clk\n");
1712 
1713 	reset_control_reset(reset);
1714 
1715 	INIT_LIST_HEAD(&dma_dev->channels);
1716 
1717 	dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
1718 	dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
1719 	dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask);
1720 	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
1721 	dma_dev->dev = &pdev->dev;
1722 	/*
1723 	 * This controller supports up to 8-byte buswidth depending on the port used and the
1724 	 * channel, and can only access address at even boundaries, multiple of the buswidth.
1725 	 */
1726 	dma_dev->copy_align = DMAENGINE_ALIGN_8_BYTES;
1727 	dma_dev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1728 				   BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1729 				   BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1730 				   BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1731 	dma_dev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1732 				   BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1733 				   BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1734 				   BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1735 	dma_dev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) | BIT(DMA_MEM_TO_MEM);
1736 
1737 	dma_dev->descriptor_reuse = true;
1738 	dma_dev->max_sg_burst = STM32_DMA3_MAX_SEG_SIZE;
1739 	dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1740 	dma_dev->device_alloc_chan_resources = stm32_dma3_alloc_chan_resources;
1741 	dma_dev->device_free_chan_resources = stm32_dma3_free_chan_resources;
1742 	dma_dev->device_prep_dma_memcpy = stm32_dma3_prep_dma_memcpy;
1743 	dma_dev->device_prep_slave_sg = stm32_dma3_prep_slave_sg;
1744 	dma_dev->device_prep_dma_cyclic = stm32_dma3_prep_dma_cyclic;
1745 	dma_dev->device_caps = stm32_dma3_caps;
1746 	dma_dev->device_config = stm32_dma3_config;
1747 	dma_dev->device_pause = stm32_dma3_pause;
1748 	dma_dev->device_resume = stm32_dma3_resume;
1749 	dma_dev->device_terminate_all = stm32_dma3_terminate_all;
1750 	dma_dev->device_synchronize = stm32_dma3_synchronize;
1751 	dma_dev->device_tx_status = stm32_dma3_tx_status;
1752 	dma_dev->device_issue_pending = stm32_dma3_issue_pending;
1753 
1754 	/* if dma_channels is not modified, get it from hwcfgr1 */
1755 	if (of_property_read_u32(np, "dma-channels", &ddata->dma_channels)) {
1756 		hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR1);
1757 		ddata->dma_channels = FIELD_GET(G_NUM_CHANNELS, hwcfgr);
1758 	}
1759 
1760 	/* if dma_requests is not modified, get it from hwcfgr2 */
1761 	if (of_property_read_u32(np, "dma-requests", &ddata->dma_requests)) {
1762 		hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR2);
1763 		ddata->dma_requests = FIELD_GET(G_MAX_REQ_ID, hwcfgr) + 1;
1764 	}
1765 
1766 	/* G_MASTER_PORTS, G_M0_DATA_WIDTH_ENC, G_M1_DATA_WIDTH_ENC in HWCFGR1 */
1767 	hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR1);
1768 	master_ports = FIELD_GET(G_MASTER_PORTS, hwcfgr);
1769 
1770 	ddata->ports_max_dw[0] = FIELD_GET(G_M0_DATA_WIDTH_ENC, hwcfgr);
1771 	if (master_ports == AXI64 || master_ports == AHB32) /* Single master port */
1772 		ddata->ports_max_dw[1] = DW_INVALID;
1773 	else /* Dual master ports */
1774 		ddata->ports_max_dw[1] = FIELD_GET(G_M1_DATA_WIDTH_ENC, hwcfgr);
1775 
1776 	/* axi_max_burst_len is optional, if not defined, use STM32_DMA3_MAX_BURST_LEN  */
1777 	ddata->axi_max_burst_len = STM32_DMA3_MAX_BURST_LEN;
1778 	pdata = device_get_match_data(&pdev->dev);
1779 	if (pdata && pdata->axi_max_burst_len) {
1780 		ddata->axi_max_burst_len = min_t(u32, pdata->axi_max_burst_len,
1781 						 STM32_DMA3_MAX_BURST_LEN);
1782 		dev_dbg(&pdev->dev, "Burst is limited to %u beats through AXI port\n",
1783 			ddata->axi_max_burst_len);
1784 	}
1785 
1786 	ddata->chans = devm_kcalloc(&pdev->dev, ddata->dma_channels, sizeof(*ddata->chans),
1787 				    GFP_KERNEL);
1788 	if (!ddata->chans) {
1789 		ret = -ENOMEM;
1790 		goto err_clk_disable;
1791 	}
1792 
1793 	chan_reserved = stm32_dma3_check_rif(ddata);
1794 
1795 	if (chan_reserved == GENMASK(ddata->dma_channels - 1, 0)) {
1796 		ret = -ENODEV;
1797 		dev_err_probe(&pdev->dev, ret, "No channel available, abort registration\n");
1798 		goto err_clk_disable;
1799 	}
1800 
1801 	/* G_FIFO_SIZE x=0..7 in HWCFGR3 and G_FIFO_SIZE x=8..15 in HWCFGR4 */
1802 	hwcfgr = readl_relaxed(ddata->base + STM32_DMA3_HWCFGR3);
1803 	hwcfgr |= ((u64)readl_relaxed(ddata->base + STM32_DMA3_HWCFGR4)) << 32;
1804 
1805 	for (i = 0; i < ddata->dma_channels; i++) {
1806 		if (chan_reserved & BIT(i))
1807 			continue;
1808 
1809 		chan = &ddata->chans[i];
1810 		chan->id = i;
1811 		chan->fifo_size = get_chan_hwcfg(i, G_FIFO_SIZE(i), hwcfgr);
1812 		/* If chan->fifo_size > 0 then half of the fifo size, else no burst when no FIFO */
1813 		chan->max_burst = (chan->fifo_size) ? (1 << (chan->fifo_size + 1)) / 2 : 0;
1814 	}
1815 
1816 	ret = dmaenginem_async_device_register(dma_dev);
1817 	if (ret)
1818 		goto err_clk_disable;
1819 
1820 	for (i = 0; i < ddata->dma_channels; i++) {
1821 		char name[12];
1822 
1823 		if (chan_reserved & BIT(i))
1824 			continue;
1825 
1826 		chan = &ddata->chans[i];
1827 		snprintf(name, sizeof(name), "dma%dchan%d", ddata->dma_dev.dev_id, chan->id);
1828 
1829 		chan->vchan.desc_free = stm32_dma3_chan_vdesc_free;
1830 		vchan_init(&chan->vchan, dma_dev);
1831 
1832 		ret = dma_async_device_channel_register(&ddata->dma_dev, &chan->vchan.chan, name);
1833 		if (ret) {
1834 			dev_err_probe(&pdev->dev, ret, "Failed to register channel %s\n", name);
1835 			goto err_clk_disable;
1836 		}
1837 
1838 		ret = platform_get_irq(pdev, i);
1839 		if (ret < 0)
1840 			goto err_clk_disable;
1841 		chan->irq = ret;
1842 
1843 		ret = devm_request_irq(&pdev->dev, chan->irq, stm32_dma3_chan_irq, 0,
1844 				       dev_name(chan2dev(chan)), chan);
1845 		if (ret) {
1846 			dev_err_probe(&pdev->dev, ret, "Failed to request channel %s IRQ\n",
1847 				      dev_name(chan2dev(chan)));
1848 			goto err_clk_disable;
1849 		}
1850 	}
1851 
1852 	ret = of_dma_controller_register(np, stm32_dma3_of_xlate, ddata);
1853 	if (ret) {
1854 		dev_err_probe(&pdev->dev, ret, "Failed to register controller\n");
1855 		goto err_clk_disable;
1856 	}
1857 
1858 	verr = readl_relaxed(ddata->base + STM32_DMA3_VERR);
1859 
1860 	pm_runtime_set_active(&pdev->dev);
1861 	pm_runtime_enable(&pdev->dev);
1862 	pm_runtime_get_noresume(&pdev->dev);
1863 	pm_runtime_put(&pdev->dev);
1864 
1865 	dev_info(&pdev->dev, "STM32 DMA3 registered rev:%lu.%lu\n",
1866 		 FIELD_GET(VERR_MAJREV, verr), FIELD_GET(VERR_MINREV, verr));
1867 
1868 	return 0;
1869 
1870 err_clk_disable:
1871 	clk_disable_unprepare(ddata->clk);
1872 
1873 	return ret;
1874 }
1875 
1876 static void stm32_dma3_remove(struct platform_device *pdev)
1877 {
1878 	pm_runtime_disable(&pdev->dev);
1879 }
1880 
1881 static int stm32_dma3_runtime_suspend(struct device *dev)
1882 {
1883 	struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
1884 
1885 	clk_disable_unprepare(ddata->clk);
1886 
1887 	return 0;
1888 }
1889 
1890 static int stm32_dma3_runtime_resume(struct device *dev)
1891 {
1892 	struct stm32_dma3_ddata *ddata = dev_get_drvdata(dev);
1893 	int ret;
1894 
1895 	ret = clk_prepare_enable(ddata->clk);
1896 	if (ret)
1897 		dev_err(dev, "Failed to enable clk: %d\n", ret);
1898 
1899 	return ret;
1900 }
1901 
1902 static const struct dev_pm_ops stm32_dma3_pm_ops = {
1903 	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
1904 	RUNTIME_PM_OPS(stm32_dma3_runtime_suspend, stm32_dma3_runtime_resume, NULL)
1905 };
1906 
1907 static struct platform_driver stm32_dma3_driver = {
1908 	.probe = stm32_dma3_probe,
1909 	.remove = stm32_dma3_remove,
1910 	.driver = {
1911 		.name = "stm32-dma3",
1912 		.of_match_table = stm32_dma3_of_match,
1913 		.pm = pm_ptr(&stm32_dma3_pm_ops),
1914 	},
1915 };
1916 
1917 static int __init stm32_dma3_init(void)
1918 {
1919 	return platform_driver_register(&stm32_dma3_driver);
1920 }
1921 
1922 subsys_initcall(stm32_dma3_init);
1923 
1924 MODULE_DESCRIPTION("STM32 DMA3 controller driver");
1925 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@foss.st.com>");
1926 MODULE_LICENSE("GPL");
1927