1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for STM32 DMA controller
4 *
5 * Inspired by dma-jz4740.c and tegra20-apb-dma.c
6 *
7 * Copyright (C) M'boumba Cedric Madianga 2015
8 * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
9 * Pierre-Yves Mordret <pierre-yves.mordret@st.com>
10 */
11
12 #include <linux/bitfield.h>
13 #include <linux/clk.h>
14 #include <linux/delay.h>
15 #include <linux/dmaengine.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/err.h>
18 #include <linux/init.h>
19 #include <linux/iopoll.h>
20 #include <linux/jiffies.h>
21 #include <linux/list.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/of_dma.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/reset.h>
28 #include <linux/sched.h>
29 #include <linux/slab.h>
30
31 #include "../virt-dma.h"
32
33 #define STM32_DMA_LISR 0x0000 /* DMA Low Int Status Reg */
34 #define STM32_DMA_HISR 0x0004 /* DMA High Int Status Reg */
35 #define STM32_DMA_ISR(n) (((n) & 4) ? STM32_DMA_HISR : STM32_DMA_LISR)
36 #define STM32_DMA_LIFCR 0x0008 /* DMA Low Int Flag Clear Reg */
37 #define STM32_DMA_HIFCR 0x000c /* DMA High Int Flag Clear Reg */
38 #define STM32_DMA_IFCR(n) (((n) & 4) ? STM32_DMA_HIFCR : STM32_DMA_LIFCR)
39 #define STM32_DMA_TCI BIT(5) /* Transfer Complete Interrupt */
40 #define STM32_DMA_HTI BIT(4) /* Half Transfer Interrupt */
41 #define STM32_DMA_TEI BIT(3) /* Transfer Error Interrupt */
42 #define STM32_DMA_DMEI BIT(2) /* Direct Mode Error Interrupt */
43 #define STM32_DMA_FEI BIT(0) /* FIFO Error Interrupt */
44 #define STM32_DMA_MASKI (STM32_DMA_TCI \
45 | STM32_DMA_TEI \
46 | STM32_DMA_DMEI \
47 | STM32_DMA_FEI)
48 /*
49 * If (chan->id % 4) is 2 or 3, left shift the mask by 16 bits;
50 * if (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
51 */
52 #define STM32_DMA_FLAGS_SHIFT(n) ({ typeof(n) (_n) = (n); \
53 (((_n) & 2) << 3) | (((_n) & 1) * 6); })
54
55 /* DMA Stream x Configuration Register */
56 #define STM32_DMA_SCR(x) (0x0010 + 0x18 * (x)) /* x = 0..7 */
57 #define STM32_DMA_SCR_REQ_MASK GENMASK(27, 25)
58 #define STM32_DMA_SCR_MBURST_MASK GENMASK(24, 23)
59 #define STM32_DMA_SCR_PBURST_MASK GENMASK(22, 21)
60 #define STM32_DMA_SCR_PL_MASK GENMASK(17, 16)
61 #define STM32_DMA_SCR_MSIZE_MASK GENMASK(14, 13)
62 #define STM32_DMA_SCR_PSIZE_MASK GENMASK(12, 11)
63 #define STM32_DMA_SCR_DIR_MASK GENMASK(7, 6)
64 #define STM32_DMA_SCR_TRBUFF BIT(20) /* Bufferable transfer for USART/UART */
65 #define STM32_DMA_SCR_CT BIT(19) /* Target in double buffer */
66 #define STM32_DMA_SCR_DBM BIT(18) /* Double Buffer Mode */
67 #define STM32_DMA_SCR_PINCOS BIT(15) /* Peripheral inc offset size */
68 #define STM32_DMA_SCR_MINC BIT(10) /* Memory increment mode */
69 #define STM32_DMA_SCR_PINC BIT(9) /* Peripheral increment mode */
70 #define STM32_DMA_SCR_CIRC BIT(8) /* Circular mode */
71 #define STM32_DMA_SCR_PFCTRL BIT(5) /* Peripheral Flow Controller */
72 #define STM32_DMA_SCR_TCIE BIT(4) /* Transfer Complete Int Enable
73 */
74 #define STM32_DMA_SCR_TEIE BIT(2) /* Transfer Error Int Enable */
75 #define STM32_DMA_SCR_DMEIE BIT(1) /* Direct Mode Err Int Enable */
76 #define STM32_DMA_SCR_EN BIT(0) /* Stream Enable */
77 #define STM32_DMA_SCR_CFG_MASK (STM32_DMA_SCR_PINC \
78 | STM32_DMA_SCR_MINC \
79 | STM32_DMA_SCR_PINCOS \
80 | STM32_DMA_SCR_PL_MASK)
81 #define STM32_DMA_SCR_IRQ_MASK (STM32_DMA_SCR_TCIE \
82 | STM32_DMA_SCR_TEIE \
83 | STM32_DMA_SCR_DMEIE)
84
85 /* DMA Stream x number of data register */
86 #define STM32_DMA_SNDTR(x) (0x0014 + 0x18 * (x))
87
88 /* DMA stream peripheral address register */
89 #define STM32_DMA_SPAR(x) (0x0018 + 0x18 * (x))
90
91 /* DMA stream x memory 0 address register */
92 #define STM32_DMA_SM0AR(x) (0x001c + 0x18 * (x))
93
94 /* DMA stream x memory 1 address register */
95 #define STM32_DMA_SM1AR(x) (0x0020 + 0x18 * (x))
96
97 /* DMA stream x FIFO control register */
98 #define STM32_DMA_SFCR(x) (0x0024 + 0x18 * (x))
99 #define STM32_DMA_SFCR_FTH_MASK GENMASK(1, 0)
100 #define STM32_DMA_SFCR_FEIE BIT(7) /* FIFO error interrupt enable */
101 #define STM32_DMA_SFCR_DMDIS BIT(2) /* Direct mode disable */
102 #define STM32_DMA_SFCR_MASK (STM32_DMA_SFCR_FEIE \
103 | STM32_DMA_SFCR_DMDIS)
104
105 /* DMA direction */
106 #define STM32_DMA_DEV_TO_MEM 0x00
107 #define STM32_DMA_MEM_TO_DEV 0x01
108 #define STM32_DMA_MEM_TO_MEM 0x02
109
110 /* DMA priority level */
111 #define STM32_DMA_PRIORITY_LOW 0x00
112 #define STM32_DMA_PRIORITY_MEDIUM 0x01
113 #define STM32_DMA_PRIORITY_HIGH 0x02
114 #define STM32_DMA_PRIORITY_VERY_HIGH 0x03
115
116 /* DMA FIFO threshold selection */
117 #define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL 0x00
118 #define STM32_DMA_FIFO_THRESHOLD_HALFFULL 0x01
119 #define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL 0x02
120 #define STM32_DMA_FIFO_THRESHOLD_FULL 0x03
121 #define STM32_DMA_FIFO_THRESHOLD_NONE 0x04
122
123 #define STM32_DMA_MAX_DATA_ITEMS 0xffff
124 /*
125 * Valid transfer starts from @0 to @0xFFFE leading to unaligned scatter
126 * gather at boundary. Thus it's safer to round down this value on FIFO
127 * size (16 Bytes)
128 */
129 #define STM32_DMA_ALIGNED_MAX_DATA_ITEMS \
130 ALIGN_DOWN(STM32_DMA_MAX_DATA_ITEMS, 16)
131 #define STM32_DMA_MAX_CHANNELS 0x08
132 #define STM32_DMA_MAX_REQUEST_ID 0x08
133 #define STM32_DMA_MAX_DATA_PARAM 0x03
134 #define STM32_DMA_FIFO_SIZE 16 /* FIFO is 16 bytes */
135 #define STM32_DMA_MIN_BURST 4
136 #define STM32_DMA_MAX_BURST 16
137
138 /* DMA Features */
139 #define STM32_DMA_THRESHOLD_FTR_MASK GENMASK(1, 0)
140 #define STM32_DMA_DIRECT_MODE_MASK BIT(2)
141 #define STM32_DMA_ALT_ACK_MODE_MASK BIT(4)
142 #define STM32_DMA_MDMA_STREAM_ID_MASK GENMASK(19, 16)
143
144 enum stm32_dma_width {
145 STM32_DMA_BYTE,
146 STM32_DMA_HALF_WORD,
147 STM32_DMA_WORD,
148 };
149
150 enum stm32_dma_burst_size {
151 STM32_DMA_BURST_SINGLE,
152 STM32_DMA_BURST_INCR4,
153 STM32_DMA_BURST_INCR8,
154 STM32_DMA_BURST_INCR16,
155 };
156
157 /**
158 * struct stm32_dma_cfg - STM32 DMA custom configuration
159 * @channel_id: channel ID
160 * @request_line: DMA request
161 * @stream_config: 32bit mask specifying the DMA channel configuration
162 * @features: 32bit mask specifying the DMA Feature list
163 */
164 struct stm32_dma_cfg {
165 u32 channel_id;
166 u32 request_line;
167 u32 stream_config;
168 u32 features;
169 };
170
171 struct stm32_dma_chan_reg {
172 u32 dma_lisr;
173 u32 dma_hisr;
174 u32 dma_lifcr;
175 u32 dma_hifcr;
176 u32 dma_scr;
177 u32 dma_sndtr;
178 u32 dma_spar;
179 u32 dma_sm0ar;
180 u32 dma_sm1ar;
181 u32 dma_sfcr;
182 };
183
184 struct stm32_dma_sg_req {
185 u32 len;
186 struct stm32_dma_chan_reg chan_reg;
187 };
188
189 struct stm32_dma_desc {
190 struct virt_dma_desc vdesc;
191 bool cyclic;
192 u32 num_sgs;
193 struct stm32_dma_sg_req sg_req[] __counted_by(num_sgs);
194 };
195
196 /**
197 * struct stm32_dma_mdma_config - STM32 DMA MDMA configuration
198 * @stream_id: DMA request to trigger STM32 MDMA transfer
199 * @ifcr: DMA interrupt flag clear register address,
200 * used by STM32 MDMA to clear DMA Transfer Complete flag
201 * @tcf: DMA Transfer Complete flag
202 */
203 struct stm32_dma_mdma_config {
204 u32 stream_id;
205 u32 ifcr;
206 u32 tcf;
207 };
208
209 struct stm32_dma_chan {
210 struct virt_dma_chan vchan;
211 bool config_init;
212 bool busy;
213 u32 id;
214 u32 irq;
215 struct stm32_dma_desc *desc;
216 u32 next_sg;
217 struct dma_slave_config dma_sconfig;
218 struct stm32_dma_chan_reg chan_reg;
219 u32 threshold;
220 u32 mem_burst;
221 u32 mem_width;
222 enum dma_status status;
223 bool trig_mdma;
224 struct stm32_dma_mdma_config mdma_config;
225 };
226
227 struct stm32_dma_device {
228 struct dma_device ddev;
229 void __iomem *base;
230 struct clk *clk;
231 bool mem2mem;
232 struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
233 };
234
stm32_dma_get_dev(struct stm32_dma_chan * chan)235 static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
236 {
237 return container_of(chan->vchan.chan.device, struct stm32_dma_device,
238 ddev);
239 }
240
to_stm32_dma_chan(struct dma_chan * c)241 static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
242 {
243 return container_of(c, struct stm32_dma_chan, vchan.chan);
244 }
245
to_stm32_dma_desc(struct virt_dma_desc * vdesc)246 static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
247 {
248 return container_of(vdesc, struct stm32_dma_desc, vdesc);
249 }
250
chan2dev(struct stm32_dma_chan * chan)251 static struct device *chan2dev(struct stm32_dma_chan *chan)
252 {
253 return &chan->vchan.chan.dev->device;
254 }
255
stm32_dma_read(struct stm32_dma_device * dmadev,u32 reg)256 static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
257 {
258 return readl_relaxed(dmadev->base + reg);
259 }
260
stm32_dma_write(struct stm32_dma_device * dmadev,u32 reg,u32 val)261 static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
262 {
263 writel_relaxed(val, dmadev->base + reg);
264 }
265
stm32_dma_get_width(struct stm32_dma_chan * chan,enum dma_slave_buswidth width)266 static int stm32_dma_get_width(struct stm32_dma_chan *chan,
267 enum dma_slave_buswidth width)
268 {
269 switch (width) {
270 case DMA_SLAVE_BUSWIDTH_1_BYTE:
271 return STM32_DMA_BYTE;
272 case DMA_SLAVE_BUSWIDTH_2_BYTES:
273 return STM32_DMA_HALF_WORD;
274 case DMA_SLAVE_BUSWIDTH_4_BYTES:
275 return STM32_DMA_WORD;
276 default:
277 dev_err(chan2dev(chan), "Dma bus width not supported\n");
278 return -EINVAL;
279 }
280 }
281
stm32_dma_get_max_width(u32 buf_len,dma_addr_t buf_addr,u32 threshold)282 static enum dma_slave_buswidth stm32_dma_get_max_width(u32 buf_len,
283 dma_addr_t buf_addr,
284 u32 threshold)
285 {
286 enum dma_slave_buswidth max_width;
287
288 if (threshold == STM32_DMA_FIFO_THRESHOLD_FULL)
289 max_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
290 else
291 max_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
292
293 while ((buf_len < max_width || buf_len % max_width) &&
294 max_width > DMA_SLAVE_BUSWIDTH_1_BYTE)
295 max_width = max_width >> 1;
296
297 if (buf_addr & (max_width - 1))
298 max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
299
300 return max_width;
301 }
302
stm32_dma_fifo_threshold_is_allowed(u32 burst,u32 threshold,enum dma_slave_buswidth width)303 static bool stm32_dma_fifo_threshold_is_allowed(u32 burst, u32 threshold,
304 enum dma_slave_buswidth width)
305 {
306 u32 remaining;
307
308 if (threshold == STM32_DMA_FIFO_THRESHOLD_NONE)
309 return false;
310
311 if (width != DMA_SLAVE_BUSWIDTH_UNDEFINED) {
312 if (burst != 0) {
313 /*
314 * If number of beats fit in several whole bursts
315 * this configuration is allowed.
316 */
317 remaining = ((STM32_DMA_FIFO_SIZE / width) *
318 (threshold + 1) / 4) % burst;
319
320 if (remaining == 0)
321 return true;
322 } else {
323 return true;
324 }
325 }
326
327 return false;
328 }
329
stm32_dma_is_burst_possible(u32 buf_len,u32 threshold)330 static bool stm32_dma_is_burst_possible(u32 buf_len, u32 threshold)
331 {
332 /* If FIFO direct mode, burst is not possible */
333 if (threshold == STM32_DMA_FIFO_THRESHOLD_NONE)
334 return false;
335
336 /*
337 * Buffer or period length has to be aligned on FIFO depth.
338 * Otherwise bytes may be stuck within FIFO at buffer or period
339 * length.
340 */
341 return ((buf_len % ((threshold + 1) * 4)) == 0);
342 }
343
stm32_dma_get_best_burst(u32 buf_len,u32 max_burst,u32 threshold,enum dma_slave_buswidth width)344 static u32 stm32_dma_get_best_burst(u32 buf_len, u32 max_burst, u32 threshold,
345 enum dma_slave_buswidth width)
346 {
347 u32 best_burst = max_burst;
348
349 if (best_burst == 1 || !stm32_dma_is_burst_possible(buf_len, threshold))
350 return 0;
351
352 while ((buf_len < best_burst * width && best_burst > 1) ||
353 !stm32_dma_fifo_threshold_is_allowed(best_burst, threshold,
354 width)) {
355 if (best_burst > STM32_DMA_MIN_BURST)
356 best_burst = best_burst >> 1;
357 else
358 best_burst = 0;
359 }
360
361 return best_burst;
362 }
363
stm32_dma_get_burst(struct stm32_dma_chan * chan,u32 maxburst)364 static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
365 {
366 switch (maxburst) {
367 case 0:
368 case 1:
369 return STM32_DMA_BURST_SINGLE;
370 case 4:
371 return STM32_DMA_BURST_INCR4;
372 case 8:
373 return STM32_DMA_BURST_INCR8;
374 case 16:
375 return STM32_DMA_BURST_INCR16;
376 default:
377 dev_err(chan2dev(chan), "Dma burst size not supported\n");
378 return -EINVAL;
379 }
380 }
381
stm32_dma_set_fifo_config(struct stm32_dma_chan * chan,u32 src_burst,u32 dst_burst)382 static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
383 u32 src_burst, u32 dst_burst)
384 {
385 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
386 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
387
388 if (!src_burst && !dst_burst) {
389 /* Using direct mode */
390 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
391 } else {
392 /* Using FIFO mode */
393 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
394 }
395 }
396
stm32_dma_slave_config(struct dma_chan * c,struct dma_slave_config * config)397 static int stm32_dma_slave_config(struct dma_chan *c,
398 struct dma_slave_config *config)
399 {
400 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
401
402 memcpy(&chan->dma_sconfig, config, sizeof(*config));
403
404 /* Check if user is requesting DMA to trigger STM32 MDMA */
405 if (config->peripheral_size) {
406 config->peripheral_config = &chan->mdma_config;
407 config->peripheral_size = sizeof(chan->mdma_config);
408 chan->trig_mdma = true;
409 }
410
411 chan->config_init = true;
412
413 return 0;
414 }
415
stm32_dma_irq_status(struct stm32_dma_chan * chan)416 static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
417 {
418 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
419 u32 flags, dma_isr;
420
421 /*
422 * Read "flags" from DMA_xISR register corresponding to the selected
423 * DMA channel at the correct bit offset inside that register.
424 */
425
426 dma_isr = stm32_dma_read(dmadev, STM32_DMA_ISR(chan->id));
427 flags = dma_isr >> STM32_DMA_FLAGS_SHIFT(chan->id);
428
429 return flags & STM32_DMA_MASKI;
430 }
431
stm32_dma_irq_clear(struct stm32_dma_chan * chan,u32 flags)432 static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
433 {
434 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
435 u32 dma_ifcr;
436
437 /*
438 * Write "flags" to the DMA_xIFCR register corresponding to the selected
439 * DMA channel at the correct bit offset inside that register.
440 */
441 flags &= STM32_DMA_MASKI;
442 dma_ifcr = flags << STM32_DMA_FLAGS_SHIFT(chan->id);
443
444 stm32_dma_write(dmadev, STM32_DMA_IFCR(chan->id), dma_ifcr);
445 }
446
stm32_dma_disable_chan(struct stm32_dma_chan * chan)447 static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
448 {
449 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
450 u32 dma_scr, id, reg;
451
452 id = chan->id;
453 reg = STM32_DMA_SCR(id);
454 dma_scr = stm32_dma_read(dmadev, reg);
455
456 if (dma_scr & STM32_DMA_SCR_EN) {
457 dma_scr &= ~STM32_DMA_SCR_EN;
458 stm32_dma_write(dmadev, reg, dma_scr);
459
460 return readl_relaxed_poll_timeout_atomic(dmadev->base + reg,
461 dma_scr, !(dma_scr & STM32_DMA_SCR_EN),
462 10, 1000000);
463 }
464
465 return 0;
466 }
467
stm32_dma_stop(struct stm32_dma_chan * chan)468 static void stm32_dma_stop(struct stm32_dma_chan *chan)
469 {
470 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
471 u32 dma_scr, dma_sfcr, status;
472 int ret;
473
474 /* Disable interrupts */
475 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
476 dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
477 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
478 dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
479 dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
480 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
481
482 /* Disable DMA */
483 ret = stm32_dma_disable_chan(chan);
484 if (ret < 0)
485 return;
486
487 /* Clear interrupt status if it is there */
488 status = stm32_dma_irq_status(chan);
489 if (status) {
490 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
491 __func__, status);
492 stm32_dma_irq_clear(chan, status);
493 }
494
495 chan->busy = false;
496 chan->status = DMA_COMPLETE;
497 }
498
stm32_dma_terminate_all(struct dma_chan * c)499 static int stm32_dma_terminate_all(struct dma_chan *c)
500 {
501 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
502 unsigned long flags;
503 LIST_HEAD(head);
504
505 spin_lock_irqsave(&chan->vchan.lock, flags);
506
507 if (chan->desc) {
508 dma_cookie_complete(&chan->desc->vdesc.tx);
509 vchan_terminate_vdesc(&chan->desc->vdesc);
510 if (chan->busy)
511 stm32_dma_stop(chan);
512 chan->desc = NULL;
513 }
514
515 vchan_get_all_descriptors(&chan->vchan, &head);
516 spin_unlock_irqrestore(&chan->vchan.lock, flags);
517 vchan_dma_desc_free_list(&chan->vchan, &head);
518
519 return 0;
520 }
521
stm32_dma_synchronize(struct dma_chan * c)522 static void stm32_dma_synchronize(struct dma_chan *c)
523 {
524 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
525
526 vchan_synchronize(&chan->vchan);
527 }
528
stm32_dma_dump_reg(struct stm32_dma_chan * chan)529 static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
530 {
531 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
532 u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
533 u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
534 u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
535 u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
536 u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
537 u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
538
539 dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr);
540 dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr);
541 dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar);
542 dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
543 dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
544 dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
545 }
546
stm32_dma_sg_inc(struct stm32_dma_chan * chan)547 static void stm32_dma_sg_inc(struct stm32_dma_chan *chan)
548 {
549 chan->next_sg++;
550 if (chan->desc->cyclic && (chan->next_sg == chan->desc->num_sgs))
551 chan->next_sg = 0;
552 }
553
554 static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan);
555
stm32_dma_start_transfer(struct stm32_dma_chan * chan)556 static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
557 {
558 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
559 struct virt_dma_desc *vdesc;
560 struct stm32_dma_sg_req *sg_req;
561 struct stm32_dma_chan_reg *reg;
562 u32 status;
563 int ret;
564
565 ret = stm32_dma_disable_chan(chan);
566 if (ret < 0)
567 return;
568
569 if (!chan->desc) {
570 vdesc = vchan_next_desc(&chan->vchan);
571 if (!vdesc)
572 return;
573
574 list_del(&vdesc->node);
575
576 chan->desc = to_stm32_dma_desc(vdesc);
577 chan->next_sg = 0;
578 }
579
580 if (chan->next_sg == chan->desc->num_sgs)
581 chan->next_sg = 0;
582
583 sg_req = &chan->desc->sg_req[chan->next_sg];
584 reg = &sg_req->chan_reg;
585
586 /* When DMA triggers STM32 MDMA, DMA Transfer Complete is managed by STM32 MDMA */
587 if (chan->trig_mdma && chan->dma_sconfig.direction != DMA_MEM_TO_DEV)
588 reg->dma_scr &= ~STM32_DMA_SCR_TCIE;
589
590 reg->dma_scr &= ~STM32_DMA_SCR_EN;
591 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
592 stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
593 stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
594 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
595 stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
596 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
597
598 stm32_dma_sg_inc(chan);
599
600 /* Clear interrupt status if it is there */
601 status = stm32_dma_irq_status(chan);
602 if (status)
603 stm32_dma_irq_clear(chan, status);
604
605 if (chan->desc->cyclic)
606 stm32_dma_configure_next_sg(chan);
607
608 stm32_dma_dump_reg(chan);
609
610 /* Start DMA */
611 chan->busy = true;
612 chan->status = DMA_IN_PROGRESS;
613 reg->dma_scr |= STM32_DMA_SCR_EN;
614 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
615
616 dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
617 }
618
stm32_dma_configure_next_sg(struct stm32_dma_chan * chan)619 static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
620 {
621 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
622 struct stm32_dma_sg_req *sg_req;
623 u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
624
625 id = chan->id;
626 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
627
628 sg_req = &chan->desc->sg_req[chan->next_sg];
629
630 if (dma_scr & STM32_DMA_SCR_CT) {
631 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
632 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
633 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
634 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
635 } else {
636 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
637 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
638 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
639 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
640 }
641 }
642
stm32_dma_handle_chan_paused(struct stm32_dma_chan * chan)643 static void stm32_dma_handle_chan_paused(struct stm32_dma_chan *chan)
644 {
645 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
646 u32 dma_scr;
647
648 /*
649 * Read and store current remaining data items and peripheral/memory addresses to be
650 * updated on resume
651 */
652 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
653 /*
654 * Transfer can be paused while between a previous resume and reconfiguration on transfer
655 * complete. If transfer is cyclic and CIRC and DBM have been deactivated for resume, need
656 * to set it here in SCR backup to ensure a good reconfiguration on transfer complete.
657 */
658 if (chan->desc && chan->desc->cyclic) {
659 if (chan->desc->num_sgs == 1)
660 dma_scr |= STM32_DMA_SCR_CIRC;
661 else
662 dma_scr |= STM32_DMA_SCR_DBM;
663 }
664 chan->chan_reg.dma_scr = dma_scr;
665
666 /*
667 * Need to temporarily deactivate CIRC/DBM until next Transfer Complete interrupt, otherwise
668 * on resume NDTR autoreload value will be wrong (lower than the initial period length)
669 */
670 if (chan->desc && chan->desc->cyclic) {
671 dma_scr &= ~(STM32_DMA_SCR_DBM | STM32_DMA_SCR_CIRC);
672 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
673 }
674
675 chan->chan_reg.dma_sndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
676
677 chan->status = DMA_PAUSED;
678
679 dev_dbg(chan2dev(chan), "vchan %pK: paused\n", &chan->vchan);
680 }
681
stm32_dma_post_resume_reconfigure(struct stm32_dma_chan * chan)682 static void stm32_dma_post_resume_reconfigure(struct stm32_dma_chan *chan)
683 {
684 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
685 struct stm32_dma_sg_req *sg_req;
686 u32 dma_scr, status, id;
687
688 id = chan->id;
689 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
690
691 /* Clear interrupt status if it is there */
692 status = stm32_dma_irq_status(chan);
693 if (status)
694 stm32_dma_irq_clear(chan, status);
695
696 if (!chan->next_sg)
697 sg_req = &chan->desc->sg_req[chan->desc->num_sgs - 1];
698 else
699 sg_req = &chan->desc->sg_req[chan->next_sg - 1];
700
701 /* Reconfigure NDTR with the initial value */
702 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), sg_req->chan_reg.dma_sndtr);
703
704 /* Restore SPAR */
705 stm32_dma_write(dmadev, STM32_DMA_SPAR(id), sg_req->chan_reg.dma_spar);
706
707 /* Restore SM0AR/SM1AR whatever DBM/CT as they may have been modified */
708 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), sg_req->chan_reg.dma_sm0ar);
709 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), sg_req->chan_reg.dma_sm1ar);
710
711 /* Reactivate CIRC/DBM if needed */
712 if (chan->chan_reg.dma_scr & STM32_DMA_SCR_DBM) {
713 dma_scr |= STM32_DMA_SCR_DBM;
714 /* Restore CT */
715 if (chan->chan_reg.dma_scr & STM32_DMA_SCR_CT)
716 dma_scr &= ~STM32_DMA_SCR_CT;
717 else
718 dma_scr |= STM32_DMA_SCR_CT;
719 } else if (chan->chan_reg.dma_scr & STM32_DMA_SCR_CIRC) {
720 dma_scr |= STM32_DMA_SCR_CIRC;
721 }
722 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
723
724 stm32_dma_configure_next_sg(chan);
725
726 stm32_dma_dump_reg(chan);
727
728 dma_scr |= STM32_DMA_SCR_EN;
729 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
730
731 dev_dbg(chan2dev(chan), "vchan %pK: reconfigured after pause/resume\n", &chan->vchan);
732 }
733
stm32_dma_handle_chan_done(struct stm32_dma_chan * chan,u32 scr)734 static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan, u32 scr)
735 {
736 if (!chan->desc)
737 return;
738
739 if (chan->desc->cyclic) {
740 vchan_cyclic_callback(&chan->desc->vdesc);
741 if (chan->trig_mdma)
742 return;
743 stm32_dma_sg_inc(chan);
744 /* cyclic while CIRC/DBM disable => post resume reconfiguration needed */
745 if (!(scr & (STM32_DMA_SCR_CIRC | STM32_DMA_SCR_DBM)))
746 stm32_dma_post_resume_reconfigure(chan);
747 else if (scr & STM32_DMA_SCR_DBM)
748 stm32_dma_configure_next_sg(chan);
749 } else {
750 chan->busy = false;
751 chan->status = DMA_COMPLETE;
752 if (chan->next_sg == chan->desc->num_sgs) {
753 vchan_cookie_complete(&chan->desc->vdesc);
754 chan->desc = NULL;
755 }
756 stm32_dma_start_transfer(chan);
757 }
758 }
759
stm32_dma_chan_irq(int irq,void * devid)760 static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
761 {
762 struct stm32_dma_chan *chan = devid;
763 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
764 u32 status, scr, sfcr;
765
766 spin_lock(&chan->vchan.lock);
767
768 status = stm32_dma_irq_status(chan);
769 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
770 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
771
772 if (status & STM32_DMA_FEI) {
773 stm32_dma_irq_clear(chan, STM32_DMA_FEI);
774 status &= ~STM32_DMA_FEI;
775 if (sfcr & STM32_DMA_SFCR_FEIE) {
776 if (!(scr & STM32_DMA_SCR_EN) &&
777 !(status & STM32_DMA_TCI))
778 dev_err(chan2dev(chan), "FIFO Error\n");
779 else
780 dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
781 }
782 }
783 if (status & STM32_DMA_DMEI) {
784 stm32_dma_irq_clear(chan, STM32_DMA_DMEI);
785 status &= ~STM32_DMA_DMEI;
786 if (sfcr & STM32_DMA_SCR_DMEIE)
787 dev_dbg(chan2dev(chan), "Direct mode overrun\n");
788 }
789
790 if (status & STM32_DMA_TCI) {
791 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
792 if (scr & STM32_DMA_SCR_TCIE) {
793 if (chan->status != DMA_PAUSED)
794 stm32_dma_handle_chan_done(chan, scr);
795 }
796 status &= ~STM32_DMA_TCI;
797 }
798
799 if (status & STM32_DMA_HTI) {
800 stm32_dma_irq_clear(chan, STM32_DMA_HTI);
801 status &= ~STM32_DMA_HTI;
802 }
803
804 if (status) {
805 stm32_dma_irq_clear(chan, status);
806 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
807 if (!(scr & STM32_DMA_SCR_EN))
808 dev_err(chan2dev(chan), "chan disabled by HW\n");
809 }
810
811 spin_unlock(&chan->vchan.lock);
812
813 return IRQ_HANDLED;
814 }
815
stm32_dma_issue_pending(struct dma_chan * c)816 static void stm32_dma_issue_pending(struct dma_chan *c)
817 {
818 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
819 unsigned long flags;
820
821 spin_lock_irqsave(&chan->vchan.lock, flags);
822 if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
823 dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
824 stm32_dma_start_transfer(chan);
825
826 }
827 spin_unlock_irqrestore(&chan->vchan.lock, flags);
828 }
829
stm32_dma_pause(struct dma_chan * c)830 static int stm32_dma_pause(struct dma_chan *c)
831 {
832 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
833 unsigned long flags;
834 int ret;
835
836 if (chan->status != DMA_IN_PROGRESS)
837 return -EPERM;
838
839 spin_lock_irqsave(&chan->vchan.lock, flags);
840
841 ret = stm32_dma_disable_chan(chan);
842 if (!ret)
843 stm32_dma_handle_chan_paused(chan);
844
845 spin_unlock_irqrestore(&chan->vchan.lock, flags);
846
847 return ret;
848 }
849
stm32_dma_resume(struct dma_chan * c)850 static int stm32_dma_resume(struct dma_chan *c)
851 {
852 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
853 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
854 struct stm32_dma_chan_reg chan_reg = chan->chan_reg;
855 u32 id = chan->id, scr, ndtr, offset, spar, sm0ar, sm1ar;
856 struct stm32_dma_sg_req *sg_req;
857 unsigned long flags;
858
859 if (chan->status != DMA_PAUSED)
860 return -EPERM;
861
862 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
863 if (WARN_ON(scr & STM32_DMA_SCR_EN))
864 return -EPERM;
865
866 spin_lock_irqsave(&chan->vchan.lock, flags);
867
868 /* sg_reg[prev_sg] contains original ndtr, sm0ar and sm1ar before pausing the transfer */
869 if (!chan->next_sg)
870 sg_req = &chan->desc->sg_req[chan->desc->num_sgs - 1];
871 else
872 sg_req = &chan->desc->sg_req[chan->next_sg - 1];
873
874 ndtr = sg_req->chan_reg.dma_sndtr;
875 offset = (ndtr - chan_reg.dma_sndtr);
876 offset <<= FIELD_GET(STM32_DMA_SCR_PSIZE_MASK, chan_reg.dma_scr);
877 spar = sg_req->chan_reg.dma_spar;
878 sm0ar = sg_req->chan_reg.dma_sm0ar;
879 sm1ar = sg_req->chan_reg.dma_sm1ar;
880
881 /*
882 * The peripheral and/or memory addresses have to be updated in order to adjust the
883 * address pointers. Need to check increment.
884 */
885 if (chan_reg.dma_scr & STM32_DMA_SCR_PINC)
886 stm32_dma_write(dmadev, STM32_DMA_SPAR(id), spar + offset);
887 else
888 stm32_dma_write(dmadev, STM32_DMA_SPAR(id), spar);
889
890 if (!(chan_reg.dma_scr & STM32_DMA_SCR_MINC))
891 offset = 0;
892
893 /*
894 * In case of DBM, the current target could be SM1AR.
895 * Need to temporarily deactivate CIRC/DBM to finish the current transfer, so
896 * SM0AR becomes the current target and must be updated with SM1AR + offset if CT=1.
897 */
898 if ((chan_reg.dma_scr & STM32_DMA_SCR_DBM) && (chan_reg.dma_scr & STM32_DMA_SCR_CT))
899 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), sm1ar + offset);
900 else
901 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), sm0ar + offset);
902
903 /* NDTR must be restored otherwise internal HW counter won't be correctly reset */
904 stm32_dma_write(dmadev, STM32_DMA_SNDTR(id), chan_reg.dma_sndtr);
905
906 /*
907 * Need to temporarily deactivate CIRC/DBM until next Transfer Complete interrupt,
908 * otherwise NDTR autoreload value will be wrong (lower than the initial period length)
909 */
910 if (chan_reg.dma_scr & (STM32_DMA_SCR_CIRC | STM32_DMA_SCR_DBM))
911 chan_reg.dma_scr &= ~(STM32_DMA_SCR_CIRC | STM32_DMA_SCR_DBM);
912
913 if (chan_reg.dma_scr & STM32_DMA_SCR_DBM)
914 stm32_dma_configure_next_sg(chan);
915
916 stm32_dma_dump_reg(chan);
917
918 /* The stream may then be re-enabled to restart transfer from the point it was stopped */
919 chan->status = DMA_IN_PROGRESS;
920 chan_reg.dma_scr |= STM32_DMA_SCR_EN;
921 stm32_dma_write(dmadev, STM32_DMA_SCR(id), chan_reg.dma_scr);
922
923 spin_unlock_irqrestore(&chan->vchan.lock, flags);
924
925 dev_dbg(chan2dev(chan), "vchan %pK: resumed\n", &chan->vchan);
926
927 return 0;
928 }
929
stm32_dma_set_xfer_param(struct stm32_dma_chan * chan,enum dma_transfer_direction direction,enum dma_slave_buswidth * buswidth,u32 buf_len,dma_addr_t buf_addr)930 static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
931 enum dma_transfer_direction direction,
932 enum dma_slave_buswidth *buswidth,
933 u32 buf_len, dma_addr_t buf_addr)
934 {
935 enum dma_slave_buswidth src_addr_width, dst_addr_width;
936 int src_bus_width, dst_bus_width;
937 int src_burst_size, dst_burst_size;
938 u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
939 u32 dma_scr, fifoth;
940
941 src_addr_width = chan->dma_sconfig.src_addr_width;
942 dst_addr_width = chan->dma_sconfig.dst_addr_width;
943 src_maxburst = chan->dma_sconfig.src_maxburst;
944 dst_maxburst = chan->dma_sconfig.dst_maxburst;
945 fifoth = chan->threshold;
946
947 switch (direction) {
948 case DMA_MEM_TO_DEV:
949 /* Set device data size */
950 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
951 if (dst_bus_width < 0)
952 return dst_bus_width;
953
954 /* Set device burst size */
955 dst_best_burst = stm32_dma_get_best_burst(buf_len,
956 dst_maxburst,
957 fifoth,
958 dst_addr_width);
959
960 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
961 if (dst_burst_size < 0)
962 return dst_burst_size;
963
964 /* Set memory data size */
965 src_addr_width = stm32_dma_get_max_width(buf_len, buf_addr,
966 fifoth);
967 chan->mem_width = src_addr_width;
968 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
969 if (src_bus_width < 0)
970 return src_bus_width;
971
972 /*
973 * Set memory burst size - burst not possible if address is not aligned on
974 * the address boundary equal to the size of the transfer
975 */
976 if (buf_addr & (buf_len - 1))
977 src_maxburst = 1;
978 else
979 src_maxburst = STM32_DMA_MAX_BURST;
980 src_best_burst = stm32_dma_get_best_burst(buf_len,
981 src_maxburst,
982 fifoth,
983 src_addr_width);
984 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
985 if (src_burst_size < 0)
986 return src_burst_size;
987
988 dma_scr = FIELD_PREP(STM32_DMA_SCR_DIR_MASK, STM32_DMA_MEM_TO_DEV) |
989 FIELD_PREP(STM32_DMA_SCR_PSIZE_MASK, dst_bus_width) |
990 FIELD_PREP(STM32_DMA_SCR_MSIZE_MASK, src_bus_width) |
991 FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, dst_burst_size) |
992 FIELD_PREP(STM32_DMA_SCR_MBURST_MASK, src_burst_size);
993
994 /* Set FIFO threshold */
995 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
996 if (fifoth != STM32_DMA_FIFO_THRESHOLD_NONE)
997 chan->chan_reg.dma_sfcr |= FIELD_PREP(STM32_DMA_SFCR_FTH_MASK, fifoth);
998
999 /* Set peripheral address */
1000 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
1001 *buswidth = dst_addr_width;
1002 break;
1003
1004 case DMA_DEV_TO_MEM:
1005 /* Set device data size */
1006 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
1007 if (src_bus_width < 0)
1008 return src_bus_width;
1009
1010 /* Set device burst size */
1011 src_best_burst = stm32_dma_get_best_burst(buf_len,
1012 src_maxburst,
1013 fifoth,
1014 src_addr_width);
1015 chan->mem_burst = src_best_burst;
1016 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
1017 if (src_burst_size < 0)
1018 return src_burst_size;
1019
1020 /* Set memory data size */
1021 dst_addr_width = stm32_dma_get_max_width(buf_len, buf_addr,
1022 fifoth);
1023 chan->mem_width = dst_addr_width;
1024 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
1025 if (dst_bus_width < 0)
1026 return dst_bus_width;
1027
1028 /*
1029 * Set memory burst size - burst not possible if address is not aligned on
1030 * the address boundary equal to the size of the transfer
1031 */
1032 if (buf_addr & (buf_len - 1))
1033 dst_maxburst = 1;
1034 else
1035 dst_maxburst = STM32_DMA_MAX_BURST;
1036 dst_best_burst = stm32_dma_get_best_burst(buf_len,
1037 dst_maxburst,
1038 fifoth,
1039 dst_addr_width);
1040 chan->mem_burst = dst_best_burst;
1041 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
1042 if (dst_burst_size < 0)
1043 return dst_burst_size;
1044
1045 dma_scr = FIELD_PREP(STM32_DMA_SCR_DIR_MASK, STM32_DMA_DEV_TO_MEM) |
1046 FIELD_PREP(STM32_DMA_SCR_PSIZE_MASK, src_bus_width) |
1047 FIELD_PREP(STM32_DMA_SCR_MSIZE_MASK, dst_bus_width) |
1048 FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, src_burst_size) |
1049 FIELD_PREP(STM32_DMA_SCR_MBURST_MASK, dst_burst_size);
1050
1051 /* Set FIFO threshold */
1052 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
1053 if (fifoth != STM32_DMA_FIFO_THRESHOLD_NONE)
1054 chan->chan_reg.dma_sfcr |= FIELD_PREP(STM32_DMA_SFCR_FTH_MASK, fifoth);
1055
1056 /* Set peripheral address */
1057 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
1058 *buswidth = chan->dma_sconfig.src_addr_width;
1059 break;
1060
1061 default:
1062 dev_err(chan2dev(chan), "Dma direction is not supported\n");
1063 return -EINVAL;
1064 }
1065
1066 stm32_dma_set_fifo_config(chan, src_best_burst, dst_best_burst);
1067
1068 /* Set DMA control register */
1069 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
1070 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
1071 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
1072 chan->chan_reg.dma_scr |= dma_scr;
1073
1074 return 0;
1075 }
1076
stm32_dma_clear_reg(struct stm32_dma_chan_reg * regs)1077 static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
1078 {
1079 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
1080 }
1081
stm32_dma_prep_slave_sg(struct dma_chan * c,struct scatterlist * sgl,u32 sg_len,enum dma_transfer_direction direction,unsigned long flags,void * context)1082 static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
1083 struct dma_chan *c, struct scatterlist *sgl,
1084 u32 sg_len, enum dma_transfer_direction direction,
1085 unsigned long flags, void *context)
1086 {
1087 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1088 struct stm32_dma_desc *desc;
1089 struct scatterlist *sg;
1090 enum dma_slave_buswidth buswidth;
1091 u32 nb_data_items;
1092 int i, ret;
1093
1094 if (!chan->config_init) {
1095 dev_err(chan2dev(chan), "dma channel is not configured\n");
1096 return NULL;
1097 }
1098
1099 if (sg_len < 1) {
1100 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
1101 return NULL;
1102 }
1103
1104 desc = kzalloc(struct_size(desc, sg_req, sg_len), GFP_NOWAIT);
1105 if (!desc)
1106 return NULL;
1107 desc->num_sgs = sg_len;
1108
1109 /* Set peripheral flow controller */
1110 if (chan->dma_sconfig.device_fc)
1111 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
1112 else
1113 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
1114
1115 /* Activate Double Buffer Mode if DMA triggers STM32 MDMA and more than 1 sg */
1116 if (chan->trig_mdma && sg_len > 1) {
1117 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
1118 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_CT;
1119 }
1120
1121 for_each_sg(sgl, sg, sg_len, i) {
1122 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth,
1123 sg_dma_len(sg),
1124 sg_dma_address(sg));
1125 if (ret < 0)
1126 goto err;
1127
1128 desc->sg_req[i].len = sg_dma_len(sg);
1129
1130 nb_data_items = desc->sg_req[i].len / buswidth;
1131 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
1132 dev_err(chan2dev(chan), "nb items not supported\n");
1133 goto err;
1134 }
1135
1136 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1137 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
1138 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
1139 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
1140 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
1141 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
1142 if (chan->trig_mdma)
1143 desc->sg_req[i].chan_reg.dma_sm1ar += sg_dma_len(sg);
1144 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
1145 }
1146 desc->cyclic = false;
1147
1148 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1149
1150 err:
1151 kfree(desc);
1152 return NULL;
1153 }
1154
stm32_dma_prep_dma_cyclic(struct dma_chan * c,dma_addr_t buf_addr,size_t buf_len,size_t period_len,enum dma_transfer_direction direction,unsigned long flags)1155 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
1156 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
1157 size_t period_len, enum dma_transfer_direction direction,
1158 unsigned long flags)
1159 {
1160 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1161 struct stm32_dma_desc *desc;
1162 enum dma_slave_buswidth buswidth;
1163 u32 num_periods, nb_data_items;
1164 int i, ret;
1165
1166 if (!buf_len || !period_len) {
1167 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
1168 return NULL;
1169 }
1170
1171 if (!chan->config_init) {
1172 dev_err(chan2dev(chan), "dma channel is not configured\n");
1173 return NULL;
1174 }
1175
1176 if (buf_len % period_len) {
1177 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
1178 return NULL;
1179 }
1180
1181 /*
1182 * We allow to take more number of requests till DMA is
1183 * not started. The driver will loop over all requests.
1184 * Once DMA is started then new requests can be queued only after
1185 * terminating the DMA.
1186 */
1187 if (chan->busy) {
1188 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
1189 return NULL;
1190 }
1191
1192 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len,
1193 buf_addr);
1194 if (ret < 0)
1195 return NULL;
1196
1197 nb_data_items = period_len / buswidth;
1198 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
1199 dev_err(chan2dev(chan), "number of items not supported\n");
1200 return NULL;
1201 }
1202
1203 /* Enable Circular mode or double buffer mode */
1204 if (buf_len == period_len) {
1205 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
1206 } else {
1207 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
1208 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_CT;
1209 }
1210
1211 /* Clear periph ctrl if client set it */
1212 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
1213
1214 num_periods = buf_len / period_len;
1215
1216 desc = kzalloc(struct_size(desc, sg_req, num_periods), GFP_NOWAIT);
1217 if (!desc)
1218 return NULL;
1219 desc->num_sgs = num_periods;
1220
1221 for (i = 0; i < num_periods; i++) {
1222 desc->sg_req[i].len = period_len;
1223
1224 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1225 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
1226 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
1227 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
1228 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
1229 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
1230 if (chan->trig_mdma)
1231 desc->sg_req[i].chan_reg.dma_sm1ar += period_len;
1232 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
1233 if (!chan->trig_mdma)
1234 buf_addr += period_len;
1235 }
1236 desc->cyclic = true;
1237
1238 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1239 }
1240
stm32_dma_prep_dma_memcpy(struct dma_chan * c,dma_addr_t dest,dma_addr_t src,size_t len,unsigned long flags)1241 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
1242 struct dma_chan *c, dma_addr_t dest,
1243 dma_addr_t src, size_t len, unsigned long flags)
1244 {
1245 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1246 enum dma_slave_buswidth max_width;
1247 struct stm32_dma_desc *desc;
1248 size_t xfer_count, offset;
1249 u32 num_sgs, best_burst, threshold;
1250 int dma_burst, i;
1251
1252 num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1253 desc = kzalloc(struct_size(desc, sg_req, num_sgs), GFP_NOWAIT);
1254 if (!desc)
1255 return NULL;
1256 desc->num_sgs = num_sgs;
1257
1258 threshold = chan->threshold;
1259
1260 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
1261 xfer_count = min_t(size_t, len - offset,
1262 STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1263
1264 /* Compute best burst size */
1265 max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1266 best_burst = stm32_dma_get_best_burst(len, STM32_DMA_MAX_BURST,
1267 threshold, max_width);
1268 dma_burst = stm32_dma_get_burst(chan, best_burst);
1269 if (dma_burst < 0) {
1270 kfree(desc);
1271 return NULL;
1272 }
1273
1274 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1275 desc->sg_req[i].chan_reg.dma_scr =
1276 FIELD_PREP(STM32_DMA_SCR_DIR_MASK, STM32_DMA_MEM_TO_MEM) |
1277 FIELD_PREP(STM32_DMA_SCR_PBURST_MASK, dma_burst) |
1278 FIELD_PREP(STM32_DMA_SCR_MBURST_MASK, dma_burst) |
1279 STM32_DMA_SCR_MINC |
1280 STM32_DMA_SCR_PINC |
1281 STM32_DMA_SCR_TCIE |
1282 STM32_DMA_SCR_TEIE;
1283 desc->sg_req[i].chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
1284 desc->sg_req[i].chan_reg.dma_sfcr |= FIELD_PREP(STM32_DMA_SFCR_FTH_MASK, threshold);
1285 desc->sg_req[i].chan_reg.dma_spar = src + offset;
1286 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
1287 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
1288 desc->sg_req[i].len = xfer_count;
1289 }
1290 desc->cyclic = false;
1291
1292 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1293 }
1294
stm32_dma_get_remaining_bytes(struct stm32_dma_chan * chan)1295 static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
1296 {
1297 u32 dma_scr, width, ndtr;
1298 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1299
1300 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
1301 width = FIELD_GET(STM32_DMA_SCR_PSIZE_MASK, dma_scr);
1302 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
1303
1304 return ndtr << width;
1305 }
1306
1307 /**
1308 * stm32_dma_is_current_sg - check that expected sg_req is currently transferred
1309 * @chan: dma channel
1310 *
1311 * This function called when IRQ are disable, checks that the hardware has not
1312 * switched on the next transfer in double buffer mode. The test is done by
1313 * comparing the next_sg memory address with the hardware related register
1314 * (based on CT bit value).
1315 *
1316 * Returns true if expected current transfer is still running or double
1317 * buffer mode is not activated.
1318 */
stm32_dma_is_current_sg(struct stm32_dma_chan * chan)1319 static bool stm32_dma_is_current_sg(struct stm32_dma_chan *chan)
1320 {
1321 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1322 struct stm32_dma_sg_req *sg_req;
1323 u32 dma_scr, dma_smar, id, period_len;
1324
1325 id = chan->id;
1326 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
1327
1328 /* In cyclic CIRC but not DBM, CT is not used */
1329 if (!(dma_scr & STM32_DMA_SCR_DBM))
1330 return true;
1331
1332 sg_req = &chan->desc->sg_req[chan->next_sg];
1333 period_len = sg_req->len;
1334
1335 /* DBM - take care of a previous pause/resume not yet post reconfigured */
1336 if (dma_scr & STM32_DMA_SCR_CT) {
1337 dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(id));
1338 /*
1339 * If transfer has been pause/resumed,
1340 * SM0AR is in the range of [SM0AR:SM0AR+period_len]
1341 */
1342 return (dma_smar >= sg_req->chan_reg.dma_sm0ar &&
1343 dma_smar < sg_req->chan_reg.dma_sm0ar + period_len);
1344 }
1345
1346 dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(id));
1347 /*
1348 * If transfer has been pause/resumed,
1349 * SM1AR is in the range of [SM1AR:SM1AR+period_len]
1350 */
1351 return (dma_smar >= sg_req->chan_reg.dma_sm1ar &&
1352 dma_smar < sg_req->chan_reg.dma_sm1ar + period_len);
1353 }
1354
stm32_dma_desc_residue(struct stm32_dma_chan * chan,struct stm32_dma_desc * desc,u32 next_sg)1355 static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
1356 struct stm32_dma_desc *desc,
1357 u32 next_sg)
1358 {
1359 u32 modulo, burst_size;
1360 u32 residue;
1361 u32 n_sg = next_sg;
1362 struct stm32_dma_sg_req *sg_req = &chan->desc->sg_req[chan->next_sg];
1363 int i;
1364
1365 /*
1366 * Calculate the residue means compute the descriptors
1367 * information:
1368 * - the sg_req currently transferred
1369 * - the Hardware remaining position in this sg (NDTR bits field).
1370 *
1371 * A race condition may occur if DMA is running in cyclic or double
1372 * buffer mode, since the DMA register are automatically reloaded at end
1373 * of period transfer. The hardware may have switched to the next
1374 * transfer (CT bit updated) just before the position (SxNDTR reg) is
1375 * read.
1376 * In this case the SxNDTR reg could (or not) correspond to the new
1377 * transfer position, and not the expected one.
1378 * The strategy implemented in the stm32 driver is to:
1379 * - read the SxNDTR register
1380 * - crosscheck that hardware is still in current transfer.
1381 * In case of switch, we can assume that the DMA is at the beginning of
1382 * the next transfer. So we approximate the residue in consequence, by
1383 * pointing on the beginning of next transfer.
1384 *
1385 * This race condition doesn't apply for none cyclic mode, as double
1386 * buffer is not used. In such situation registers are updated by the
1387 * software.
1388 */
1389
1390 residue = stm32_dma_get_remaining_bytes(chan);
1391
1392 if ((chan->desc->cyclic || chan->trig_mdma) && !stm32_dma_is_current_sg(chan)) {
1393 n_sg++;
1394 if (n_sg == chan->desc->num_sgs)
1395 n_sg = 0;
1396 if (!chan->trig_mdma)
1397 residue = sg_req->len;
1398 }
1399
1400 /*
1401 * In cyclic mode, for the last period, residue = remaining bytes
1402 * from NDTR,
1403 * else for all other periods in cyclic mode, and in sg mode,
1404 * residue = remaining bytes from NDTR + remaining
1405 * periods/sg to be transferred
1406 */
1407 if ((!chan->desc->cyclic && !chan->trig_mdma) || n_sg != 0)
1408 for (i = n_sg; i < desc->num_sgs; i++)
1409 residue += desc->sg_req[i].len;
1410
1411 if (!chan->mem_burst)
1412 return residue;
1413
1414 burst_size = chan->mem_burst * chan->mem_width;
1415 modulo = residue % burst_size;
1416 if (modulo)
1417 residue = residue - modulo + burst_size;
1418
1419 return residue;
1420 }
1421
stm32_dma_tx_status(struct dma_chan * c,dma_cookie_t cookie,struct dma_tx_state * state)1422 static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
1423 dma_cookie_t cookie,
1424 struct dma_tx_state *state)
1425 {
1426 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1427 struct virt_dma_desc *vdesc;
1428 enum dma_status status;
1429 unsigned long flags;
1430 u32 residue = 0;
1431
1432 status = dma_cookie_status(c, cookie, state);
1433 if (status == DMA_COMPLETE)
1434 return status;
1435
1436 status = chan->status;
1437
1438 if (!state)
1439 return status;
1440
1441 spin_lock_irqsave(&chan->vchan.lock, flags);
1442 vdesc = vchan_find_desc(&chan->vchan, cookie);
1443 if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1444 residue = stm32_dma_desc_residue(chan, chan->desc,
1445 chan->next_sg);
1446 else if (vdesc)
1447 residue = stm32_dma_desc_residue(chan,
1448 to_stm32_dma_desc(vdesc), 0);
1449 dma_set_residue(state, residue);
1450
1451 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1452
1453 return status;
1454 }
1455
stm32_dma_alloc_chan_resources(struct dma_chan * c)1456 static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
1457 {
1458 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1459 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1460 int ret;
1461
1462 chan->config_init = false;
1463
1464 ret = pm_runtime_resume_and_get(dmadev->ddev.dev);
1465 if (ret < 0)
1466 return ret;
1467
1468 ret = stm32_dma_disable_chan(chan);
1469 if (ret < 0)
1470 pm_runtime_put(dmadev->ddev.dev);
1471
1472 return ret;
1473 }
1474
stm32_dma_free_chan_resources(struct dma_chan * c)1475 static void stm32_dma_free_chan_resources(struct dma_chan *c)
1476 {
1477 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1478 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1479 unsigned long flags;
1480
1481 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1482
1483 if (chan->busy) {
1484 spin_lock_irqsave(&chan->vchan.lock, flags);
1485 stm32_dma_stop(chan);
1486 chan->desc = NULL;
1487 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1488 }
1489
1490 pm_runtime_put(dmadev->ddev.dev);
1491
1492 vchan_free_chan_resources(to_virt_chan(c));
1493 stm32_dma_clear_reg(&chan->chan_reg);
1494 chan->threshold = 0;
1495 }
1496
stm32_dma_desc_free(struct virt_dma_desc * vdesc)1497 static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
1498 {
1499 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
1500 }
1501
stm32_dma_set_config(struct stm32_dma_chan * chan,struct stm32_dma_cfg * cfg)1502 static void stm32_dma_set_config(struct stm32_dma_chan *chan,
1503 struct stm32_dma_cfg *cfg)
1504 {
1505 stm32_dma_clear_reg(&chan->chan_reg);
1506
1507 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
1508 chan->chan_reg.dma_scr |= FIELD_PREP(STM32_DMA_SCR_REQ_MASK, cfg->request_line);
1509
1510 /* Enable Interrupts */
1511 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
1512
1513 chan->threshold = FIELD_GET(STM32_DMA_THRESHOLD_FTR_MASK, cfg->features);
1514 if (FIELD_GET(STM32_DMA_DIRECT_MODE_MASK, cfg->features))
1515 chan->threshold = STM32_DMA_FIFO_THRESHOLD_NONE;
1516 if (FIELD_GET(STM32_DMA_ALT_ACK_MODE_MASK, cfg->features))
1517 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TRBUFF;
1518 chan->mdma_config.stream_id = FIELD_GET(STM32_DMA_MDMA_STREAM_ID_MASK, cfg->features);
1519 }
1520
stm32_dma_of_xlate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)1521 static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
1522 struct of_dma *ofdma)
1523 {
1524 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
1525 struct device *dev = dmadev->ddev.dev;
1526 struct stm32_dma_cfg cfg;
1527 struct stm32_dma_chan *chan;
1528 struct dma_chan *c;
1529
1530 if (dma_spec->args_count < 4) {
1531 dev_err(dev, "Bad number of cells\n");
1532 return NULL;
1533 }
1534
1535 cfg.channel_id = dma_spec->args[0];
1536 cfg.request_line = dma_spec->args[1];
1537 cfg.stream_config = dma_spec->args[2];
1538 cfg.features = dma_spec->args[3];
1539
1540 if (cfg.channel_id >= STM32_DMA_MAX_CHANNELS ||
1541 cfg.request_line >= STM32_DMA_MAX_REQUEST_ID) {
1542 dev_err(dev, "Bad channel and/or request id\n");
1543 return NULL;
1544 }
1545
1546 chan = &dmadev->chan[cfg.channel_id];
1547
1548 c = dma_get_slave_channel(&chan->vchan.chan);
1549 if (!c) {
1550 dev_err(dev, "No more channels available\n");
1551 return NULL;
1552 }
1553
1554 stm32_dma_set_config(chan, &cfg);
1555
1556 return c;
1557 }
1558
1559 static const struct of_device_id stm32_dma_of_match[] = {
1560 { .compatible = "st,stm32-dma", },
1561 { /* sentinel */ },
1562 };
1563 MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1564
stm32_dma_probe(struct platform_device * pdev)1565 static int stm32_dma_probe(struct platform_device *pdev)
1566 {
1567 struct stm32_dma_chan *chan;
1568 struct stm32_dma_device *dmadev;
1569 struct dma_device *dd;
1570 struct resource *res;
1571 struct reset_control *rst;
1572 int i, ret;
1573
1574 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1575 if (!dmadev)
1576 return -ENOMEM;
1577
1578 dd = &dmadev->ddev;
1579
1580 dmadev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1581 if (IS_ERR(dmadev->base))
1582 return PTR_ERR(dmadev->base);
1583
1584 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1585 if (IS_ERR(dmadev->clk))
1586 return dev_err_probe(&pdev->dev, PTR_ERR(dmadev->clk), "Can't get clock\n");
1587
1588 ret = clk_prepare_enable(dmadev->clk);
1589 if (ret < 0) {
1590 dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
1591 return ret;
1592 }
1593
1594 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1595 "st,mem2mem");
1596
1597 rst = devm_reset_control_get(&pdev->dev, NULL);
1598 if (IS_ERR(rst)) {
1599 ret = PTR_ERR(rst);
1600 if (ret == -EPROBE_DEFER)
1601 goto clk_free;
1602 } else {
1603 reset_control_assert(rst);
1604 udelay(2);
1605 reset_control_deassert(rst);
1606 }
1607
1608 dma_set_max_seg_size(&pdev->dev, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1609
1610 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1611 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1612 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1613 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1614 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1615 dd->device_tx_status = stm32_dma_tx_status;
1616 dd->device_issue_pending = stm32_dma_issue_pending;
1617 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1618 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1619 dd->device_config = stm32_dma_slave_config;
1620 dd->device_pause = stm32_dma_pause;
1621 dd->device_resume = stm32_dma_resume;
1622 dd->device_terminate_all = stm32_dma_terminate_all;
1623 dd->device_synchronize = stm32_dma_synchronize;
1624 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1625 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1626 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1627 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1628 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1629 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1630 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1631 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1632 dd->copy_align = DMAENGINE_ALIGN_32_BYTES;
1633 dd->max_burst = STM32_DMA_MAX_BURST;
1634 dd->max_sg_burst = STM32_DMA_ALIGNED_MAX_DATA_ITEMS;
1635 dd->descriptor_reuse = true;
1636 dd->dev = &pdev->dev;
1637 INIT_LIST_HEAD(&dd->channels);
1638
1639 if (dmadev->mem2mem) {
1640 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1641 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1642 dd->directions |= BIT(DMA_MEM_TO_MEM);
1643 }
1644
1645 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1646 chan = &dmadev->chan[i];
1647 chan->id = i;
1648 chan->vchan.desc_free = stm32_dma_desc_free;
1649 vchan_init(&chan->vchan, dd);
1650
1651 chan->mdma_config.ifcr = res->start;
1652 chan->mdma_config.ifcr += STM32_DMA_IFCR(chan->id);
1653
1654 chan->mdma_config.tcf = STM32_DMA_TCI;
1655 chan->mdma_config.tcf <<= STM32_DMA_FLAGS_SHIFT(chan->id);
1656 }
1657
1658 ret = dma_async_device_register(dd);
1659 if (ret)
1660 goto clk_free;
1661
1662 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1663 chan = &dmadev->chan[i];
1664 ret = platform_get_irq(pdev, i);
1665 if (ret < 0)
1666 goto err_unregister;
1667 chan->irq = ret;
1668
1669 ret = devm_request_irq(&pdev->dev, chan->irq,
1670 stm32_dma_chan_irq, 0,
1671 dev_name(chan2dev(chan)), chan);
1672 if (ret) {
1673 dev_err(&pdev->dev,
1674 "request_irq failed with err %d channel %d\n",
1675 ret, i);
1676 goto err_unregister;
1677 }
1678 }
1679
1680 ret = of_dma_controller_register(pdev->dev.of_node,
1681 stm32_dma_of_xlate, dmadev);
1682 if (ret < 0) {
1683 dev_err(&pdev->dev,
1684 "STM32 DMA DMA OF registration failed %d\n", ret);
1685 goto err_unregister;
1686 }
1687
1688 platform_set_drvdata(pdev, dmadev);
1689
1690 pm_runtime_set_active(&pdev->dev);
1691 pm_runtime_enable(&pdev->dev);
1692 pm_runtime_get_noresume(&pdev->dev);
1693 pm_runtime_put(&pdev->dev);
1694
1695 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1696
1697 return 0;
1698
1699 err_unregister:
1700 dma_async_device_unregister(dd);
1701 clk_free:
1702 clk_disable_unprepare(dmadev->clk);
1703
1704 return ret;
1705 }
1706
1707 #ifdef CONFIG_PM
stm32_dma_runtime_suspend(struct device * dev)1708 static int stm32_dma_runtime_suspend(struct device *dev)
1709 {
1710 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1711
1712 clk_disable_unprepare(dmadev->clk);
1713
1714 return 0;
1715 }
1716
stm32_dma_runtime_resume(struct device * dev)1717 static int stm32_dma_runtime_resume(struct device *dev)
1718 {
1719 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1720 int ret;
1721
1722 ret = clk_prepare_enable(dmadev->clk);
1723 if (ret) {
1724 dev_err(dev, "failed to prepare_enable clock\n");
1725 return ret;
1726 }
1727
1728 return 0;
1729 }
1730 #endif
1731
1732 #ifdef CONFIG_PM_SLEEP
stm32_dma_pm_suspend(struct device * dev)1733 static int stm32_dma_pm_suspend(struct device *dev)
1734 {
1735 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1736 int id, ret, scr;
1737
1738 ret = pm_runtime_resume_and_get(dev);
1739 if (ret < 0)
1740 return ret;
1741
1742 for (id = 0; id < STM32_DMA_MAX_CHANNELS; id++) {
1743 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
1744 if (scr & STM32_DMA_SCR_EN) {
1745 dev_warn(dev, "Suspend is prevented by Chan %i\n", id);
1746 return -EBUSY;
1747 }
1748 }
1749
1750 pm_runtime_put_sync(dev);
1751
1752 pm_runtime_force_suspend(dev);
1753
1754 return 0;
1755 }
1756
stm32_dma_pm_resume(struct device * dev)1757 static int stm32_dma_pm_resume(struct device *dev)
1758 {
1759 return pm_runtime_force_resume(dev);
1760 }
1761 #endif
1762
1763 static const struct dev_pm_ops stm32_dma_pm_ops = {
1764 SET_SYSTEM_SLEEP_PM_OPS(stm32_dma_pm_suspend, stm32_dma_pm_resume)
1765 SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend,
1766 stm32_dma_runtime_resume, NULL)
1767 };
1768
1769 static struct platform_driver stm32_dma_driver = {
1770 .driver = {
1771 .name = "stm32-dma",
1772 .of_match_table = stm32_dma_of_match,
1773 .pm = &stm32_dma_pm_ops,
1774 },
1775 .probe = stm32_dma_probe,
1776 };
1777
stm32_dma_init(void)1778 static int __init stm32_dma_init(void)
1779 {
1780 return platform_driver_register(&stm32_dma_driver);
1781 }
1782 subsys_initcall(stm32_dma_init);
1783