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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/clk.h>
13#include <linux/delay.h>
14#include <linux/dmaengine.h>
15#include <linux/dma-mapping.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/jiffies.h>
19#include <linux/list.h>
20#include <linux/module.h>
21#include <linux/of.h>
22#include <linux/of_device.h>
23#include <linux/of_dma.h>
24#include <linux/platform_device.h>
25#include <linux/pm_runtime.h>
26#include <linux/reset.h>
27#include <linux/sched.h>
28#include <linux/slab.h>
29
30#include "virt-dma.h"
31
32#define STM32_DMA_LISR 0x0000 /* DMA Low Int Status Reg */
33#define STM32_DMA_HISR 0x0004 /* DMA High Int Status Reg */
34#define STM32_DMA_LIFCR 0x0008 /* DMA Low Int Flag Clear Reg */
35#define STM32_DMA_HIFCR 0x000c /* DMA High Int Flag Clear Reg */
36#define STM32_DMA_TCI BIT(5) /* Transfer Complete Interrupt */
37#define STM32_DMA_HTI BIT(4) /* Half Transfer Interrupt */
38#define STM32_DMA_TEI BIT(3) /* Transfer Error Interrupt */
39#define STM32_DMA_DMEI BIT(2) /* Direct Mode Error Interrupt */
40#define STM32_DMA_FEI BIT(0) /* FIFO Error Interrupt */
41#define STM32_DMA_MASKI (STM32_DMA_TCI \
42 | STM32_DMA_TEI \
43 | STM32_DMA_DMEI \
44 | STM32_DMA_FEI)
45
46/* DMA Stream x Configuration Register */
47#define STM32_DMA_SCR(x) (0x0010 + 0x18 * (x)) /* x = 0..7 */
48#define STM32_DMA_SCR_REQ(n) ((n & 0x7) << 25)
49#define STM32_DMA_SCR_MBURST_MASK GENMASK(24, 23)
50#define STM32_DMA_SCR_MBURST(n) ((n & 0x3) << 23)
51#define STM32_DMA_SCR_PBURST_MASK GENMASK(22, 21)
52#define STM32_DMA_SCR_PBURST(n) ((n & 0x3) << 21)
53#define STM32_DMA_SCR_PL_MASK GENMASK(17, 16)
54#define STM32_DMA_SCR_PL(n) ((n & 0x3) << 16)
55#define STM32_DMA_SCR_MSIZE_MASK GENMASK(14, 13)
56#define STM32_DMA_SCR_MSIZE(n) ((n & 0x3) << 13)
57#define STM32_DMA_SCR_PSIZE_MASK GENMASK(12, 11)
58#define STM32_DMA_SCR_PSIZE(n) ((n & 0x3) << 11)
59#define STM32_DMA_SCR_PSIZE_GET(n) ((n & STM32_DMA_SCR_PSIZE_MASK) >> 11)
60#define STM32_DMA_SCR_DIR_MASK GENMASK(7, 6)
61#define STM32_DMA_SCR_DIR(n) ((n & 0x3) << 6)
62#define STM32_DMA_SCR_CT BIT(19) /* Target in double buffer */
63#define STM32_DMA_SCR_DBM BIT(18) /* Double Buffer Mode */
64#define STM32_DMA_SCR_PINCOS BIT(15) /* Peripheral inc offset size */
65#define STM32_DMA_SCR_MINC BIT(10) /* Memory increment mode */
66#define STM32_DMA_SCR_PINC BIT(9) /* Peripheral increment mode */
67#define STM32_DMA_SCR_CIRC BIT(8) /* Circular mode */
68#define STM32_DMA_SCR_PFCTRL BIT(5) /* Peripheral Flow Controller */
69#define STM32_DMA_SCR_TCIE BIT(4) /* Transfer Complete Int Enable
70 */
71#define STM32_DMA_SCR_TEIE BIT(2) /* Transfer Error Int Enable */
72#define STM32_DMA_SCR_DMEIE BIT(1) /* Direct Mode Err Int Enable */
73#define STM32_DMA_SCR_EN BIT(0) /* Stream Enable */
74#define STM32_DMA_SCR_CFG_MASK (STM32_DMA_SCR_PINC \
75 | STM32_DMA_SCR_MINC \
76 | STM32_DMA_SCR_PINCOS \
77 | STM32_DMA_SCR_PL_MASK)
78#define STM32_DMA_SCR_IRQ_MASK (STM32_DMA_SCR_TCIE \
79 | STM32_DMA_SCR_TEIE \
80 | STM32_DMA_SCR_DMEIE)
81
82/* DMA Stream x number of data register */
83#define STM32_DMA_SNDTR(x) (0x0014 + 0x18 * (x))
84
85/* DMA stream peripheral address register */
86#define STM32_DMA_SPAR(x) (0x0018 + 0x18 * (x))
87
88/* DMA stream x memory 0 address register */
89#define STM32_DMA_SM0AR(x) (0x001c + 0x18 * (x))
90
91/* DMA stream x memory 1 address register */
92#define STM32_DMA_SM1AR(x) (0x0020 + 0x18 * (x))
93
94/* DMA stream x FIFO control register */
95#define STM32_DMA_SFCR(x) (0x0024 + 0x18 * (x))
96#define STM32_DMA_SFCR_FTH_MASK GENMASK(1, 0)
97#define STM32_DMA_SFCR_FTH(n) (n & STM32_DMA_SFCR_FTH_MASK)
98#define STM32_DMA_SFCR_FEIE BIT(7) /* FIFO error interrupt enable */
99#define STM32_DMA_SFCR_DMDIS BIT(2) /* Direct mode disable */
100#define STM32_DMA_SFCR_MASK (STM32_DMA_SFCR_FEIE \
101 | STM32_DMA_SFCR_DMDIS)
102
103/* DMA direction */
104#define STM32_DMA_DEV_TO_MEM 0x00
105#define STM32_DMA_MEM_TO_DEV 0x01
106#define STM32_DMA_MEM_TO_MEM 0x02
107
108/* DMA priority level */
109#define STM32_DMA_PRIORITY_LOW 0x00
110#define STM32_DMA_PRIORITY_MEDIUM 0x01
111#define STM32_DMA_PRIORITY_HIGH 0x02
112#define STM32_DMA_PRIORITY_VERY_HIGH 0x03
113
114/* DMA FIFO threshold selection */
115#define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL 0x00
116#define STM32_DMA_FIFO_THRESHOLD_HALFFULL 0x01
117#define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL 0x02
118#define STM32_DMA_FIFO_THRESHOLD_FULL 0x03
119
120#define STM32_DMA_MAX_DATA_ITEMS 0xffff
121/*
122 * Valid transfer starts from @0 to @0xFFFE leading to unaligned scatter
123 * gather at boundary. Thus it's safer to round down this value on FIFO
124 * size (16 Bytes)
125 */
126#define STM32_DMA_ALIGNED_MAX_DATA_ITEMS \
127 ALIGN_DOWN(STM32_DMA_MAX_DATA_ITEMS, 16)
128#define STM32_DMA_MAX_CHANNELS 0x08
129#define STM32_DMA_MAX_REQUEST_ID 0x08
130#define STM32_DMA_MAX_DATA_PARAM 0x03
131#define STM32_DMA_FIFO_SIZE 16 /* FIFO is 16 bytes */
132#define STM32_DMA_MIN_BURST 4
133#define STM32_DMA_MAX_BURST 16
134
135/* DMA Features */
136#define STM32_DMA_THRESHOLD_FTR_MASK GENMASK(1, 0)
137#define STM32_DMA_THRESHOLD_FTR_GET(n) ((n) & STM32_DMA_THRESHOLD_FTR_MASK)
138
139enum stm32_dma_width {
140 STM32_DMA_BYTE,
141 STM32_DMA_HALF_WORD,
142 STM32_DMA_WORD,
143};
144
145enum stm32_dma_burst_size {
146 STM32_DMA_BURST_SINGLE,
147 STM32_DMA_BURST_INCR4,
148 STM32_DMA_BURST_INCR8,
149 STM32_DMA_BURST_INCR16,
150};
151
152/**
153 * struct stm32_dma_cfg - STM32 DMA custom configuration
154 * @channel_id: channel ID
155 * @request_line: DMA request
156 * @stream_config: 32bit mask specifying the DMA channel configuration
157 * @features: 32bit mask specifying the DMA Feature list
158 */
159struct stm32_dma_cfg {
160 u32 channel_id;
161 u32 request_line;
162 u32 stream_config;
163 u32 features;
164};
165
166struct stm32_dma_chan_reg {
167 u32 dma_lisr;
168 u32 dma_hisr;
169 u32 dma_lifcr;
170 u32 dma_hifcr;
171 u32 dma_scr;
172 u32 dma_sndtr;
173 u32 dma_spar;
174 u32 dma_sm0ar;
175 u32 dma_sm1ar;
176 u32 dma_sfcr;
177};
178
179struct stm32_dma_sg_req {
180 u32 len;
181 struct stm32_dma_chan_reg chan_reg;
182};
183
184struct stm32_dma_desc {
185 struct virt_dma_desc vdesc;
186 bool cyclic;
187 u32 num_sgs;
188 struct stm32_dma_sg_req sg_req[];
189};
190
191struct stm32_dma_chan {
192 struct virt_dma_chan vchan;
193 bool config_init;
194 bool busy;
195 u32 id;
196 u32 irq;
197 struct stm32_dma_desc *desc;
198 u32 next_sg;
199 struct dma_slave_config dma_sconfig;
200 struct stm32_dma_chan_reg chan_reg;
201 u32 threshold;
202 u32 mem_burst;
203 u32 mem_width;
204};
205
206struct stm32_dma_device {
207 struct dma_device ddev;
208 void __iomem *base;
209 struct clk *clk;
210 struct reset_control *rst;
211 bool mem2mem;
212 struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
213};
214
215static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
216{
217 return container_of(chan->vchan.chan.device, struct stm32_dma_device,
218 ddev);
219}
220
221static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
222{
223 return container_of(c, struct stm32_dma_chan, vchan.chan);
224}
225
226static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
227{
228 return container_of(vdesc, struct stm32_dma_desc, vdesc);
229}
230
231static struct device *chan2dev(struct stm32_dma_chan *chan)
232{
233 return &chan->vchan.chan.dev->device;
234}
235
236static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
237{
238 return readl_relaxed(dmadev->base + reg);
239}
240
241static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
242{
243 writel_relaxed(val, dmadev->base + reg);
244}
245
246static int stm32_dma_get_width(struct stm32_dma_chan *chan,
247 enum dma_slave_buswidth width)
248{
249 switch (width) {
250 case DMA_SLAVE_BUSWIDTH_1_BYTE:
251 return STM32_DMA_BYTE;
252 case DMA_SLAVE_BUSWIDTH_2_BYTES:
253 return STM32_DMA_HALF_WORD;
254 case DMA_SLAVE_BUSWIDTH_4_BYTES:
255 return STM32_DMA_WORD;
256 default:
257 dev_err(chan2dev(chan), "Dma bus width not supported\n");
258 return -EINVAL;
259 }
260}
261
262static enum dma_slave_buswidth stm32_dma_get_max_width(u32 buf_len,
263 u32 threshold)
264{
265 enum dma_slave_buswidth max_width;
266
267 if (threshold == STM32_DMA_FIFO_THRESHOLD_FULL)
268 max_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
269 else
270 max_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
271
272 while ((buf_len < max_width || buf_len % max_width) &&
273 max_width > DMA_SLAVE_BUSWIDTH_1_BYTE)
274 max_width = max_width >> 1;
275
276 return max_width;
277}
278
279static bool stm32_dma_fifo_threshold_is_allowed(u32 burst, u32 threshold,
280 enum dma_slave_buswidth width)
281{
282 u32 remaining;
283
284 if (width != DMA_SLAVE_BUSWIDTH_UNDEFINED) {
285 if (burst != 0) {
286 /*
287 * If number of beats fit in several whole bursts
288 * this configuration is allowed.
289 */
290 remaining = ((STM32_DMA_FIFO_SIZE / width) *
291 (threshold + 1) / 4) % burst;
292
293 if (remaining == 0)
294 return true;
295 } else {
296 return true;
297 }
298 }
299
300 return false;
301}
302
303static bool stm32_dma_is_burst_possible(u32 buf_len, u32 threshold)
304{
305 /*
306 * Buffer or period length has to be aligned on FIFO depth.
307 * Otherwise bytes may be stuck within FIFO at buffer or period
308 * length.
309 */
310 return ((buf_len % ((threshold + 1) * 4)) == 0);
311}
312
313static u32 stm32_dma_get_best_burst(u32 buf_len, u32 max_burst, u32 threshold,
314 enum dma_slave_buswidth width)
315{
316 u32 best_burst = max_burst;
317
318 if (best_burst == 1 || !stm32_dma_is_burst_possible(buf_len, threshold))
319 return 0;
320
321 while ((buf_len < best_burst * width && best_burst > 1) ||
322 !stm32_dma_fifo_threshold_is_allowed(best_burst, threshold,
323 width)) {
324 if (best_burst > STM32_DMA_MIN_BURST)
325 best_burst = best_burst >> 1;
326 else
327 best_burst = 0;
328 }
329
330 return best_burst;
331}
332
333static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
334{
335 switch (maxburst) {
336 case 0:
337 case 1:
338 return STM32_DMA_BURST_SINGLE;
339 case 4:
340 return STM32_DMA_BURST_INCR4;
341 case 8:
342 return STM32_DMA_BURST_INCR8;
343 case 16:
344 return STM32_DMA_BURST_INCR16;
345 default:
346 dev_err(chan2dev(chan), "Dma burst size not supported\n");
347 return -EINVAL;
348 }
349}
350
351static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
352 u32 src_burst, u32 dst_burst)
353{
354 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
355 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
356
357 if (!src_burst && !dst_burst) {
358 /* Using direct mode */
359 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
360 } else {
361 /* Using FIFO mode */
362 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
363 }
364}
365
366static int stm32_dma_slave_config(struct dma_chan *c,
367 struct dma_slave_config *config)
368{
369 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
370
371 memcpy(&chan->dma_sconfig, config, sizeof(*config));
372
373 chan->config_init = true;
374
375 return 0;
376}
377
378static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
379{
380 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
381 u32 flags, dma_isr;
382
383 /*
384 * Read "flags" from DMA_xISR register corresponding to the selected
385 * DMA channel at the correct bit offset inside that register.
386 *
387 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
388 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
389 */
390
391 if (chan->id & 4)
392 dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR);
393 else
394 dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR);
395
396 flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
397
398 return flags & STM32_DMA_MASKI;
399}
400
401static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
402{
403 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
404 u32 dma_ifcr;
405
406 /*
407 * Write "flags" to the DMA_xIFCR register corresponding to the selected
408 * DMA channel at the correct bit offset inside that register.
409 *
410 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
411 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
412 */
413 flags &= STM32_DMA_MASKI;
414 dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
415
416 if (chan->id & 4)
417 stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr);
418 else
419 stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr);
420}
421
422static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
423{
424 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
425 unsigned long timeout = jiffies + msecs_to_jiffies(5000);
426 u32 dma_scr, id;
427
428 id = chan->id;
429 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
430
431 if (dma_scr & STM32_DMA_SCR_EN) {
432 dma_scr &= ~STM32_DMA_SCR_EN;
433 stm32_dma_write(dmadev, STM32_DMA_SCR(id), dma_scr);
434
435 do {
436 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
437 dma_scr &= STM32_DMA_SCR_EN;
438 if (!dma_scr)
439 break;
440
441 if (time_after_eq(jiffies, timeout)) {
442 dev_err(chan2dev(chan), "%s: timeout!\n",
443 __func__);
444 return -EBUSY;
445 }
446 cond_resched();
447 } while (1);
448 }
449
450 return 0;
451}
452
453static void stm32_dma_stop(struct stm32_dma_chan *chan)
454{
455 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
456 u32 dma_scr, dma_sfcr, status;
457 int ret;
458
459 /* Disable interrupts */
460 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
461 dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
462 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
463 dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
464 dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
465 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
466
467 /* Disable DMA */
468 ret = stm32_dma_disable_chan(chan);
469 if (ret < 0)
470 return;
471
472 /* Clear interrupt status if it is there */
473 status = stm32_dma_irq_status(chan);
474 if (status) {
475 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
476 __func__, status);
477 stm32_dma_irq_clear(chan, status);
478 }
479
480 chan->busy = false;
481}
482
483static int stm32_dma_terminate_all(struct dma_chan *c)
484{
485 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
486 unsigned long flags;
487 LIST_HEAD(head);
488
489 spin_lock_irqsave(&chan->vchan.lock, flags);
490
491 if (chan->busy) {
492 stm32_dma_stop(chan);
493 chan->desc = NULL;
494 }
495
496 vchan_get_all_descriptors(&chan->vchan, &head);
497 spin_unlock_irqrestore(&chan->vchan.lock, flags);
498 vchan_dma_desc_free_list(&chan->vchan, &head);
499
500 return 0;
501}
502
503static void stm32_dma_synchronize(struct dma_chan *c)
504{
505 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
506
507 vchan_synchronize(&chan->vchan);
508}
509
510static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
511{
512 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
513 u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
514 u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
515 u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
516 u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
517 u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
518 u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
519
520 dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr);
521 dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr);
522 dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar);
523 dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
524 dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
525 dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
526}
527
528static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan);
529
530static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
531{
532 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
533 struct virt_dma_desc *vdesc;
534 struct stm32_dma_sg_req *sg_req;
535 struct stm32_dma_chan_reg *reg;
536 u32 status;
537 int ret;
538
539 ret = stm32_dma_disable_chan(chan);
540 if (ret < 0)
541 return;
542
543 if (!chan->desc) {
544 vdesc = vchan_next_desc(&chan->vchan);
545 if (!vdesc)
546 return;
547
548 chan->desc = to_stm32_dma_desc(vdesc);
549 chan->next_sg = 0;
550 }
551
552 if (chan->next_sg == chan->desc->num_sgs)
553 chan->next_sg = 0;
554
555 sg_req = &chan->desc->sg_req[chan->next_sg];
556 reg = &sg_req->chan_reg;
557
558 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
559 stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
560 stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
561 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
562 stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
563 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
564
565 chan->next_sg++;
566
567 /* Clear interrupt status if it is there */
568 status = stm32_dma_irq_status(chan);
569 if (status)
570 stm32_dma_irq_clear(chan, status);
571
572 if (chan->desc->cyclic)
573 stm32_dma_configure_next_sg(chan);
574
575 stm32_dma_dump_reg(chan);
576
577 /* Start DMA */
578 reg->dma_scr |= STM32_DMA_SCR_EN;
579 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
580
581 chan->busy = true;
582
583 dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
584}
585
586static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
587{
588 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
589 struct stm32_dma_sg_req *sg_req;
590 u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
591
592 id = chan->id;
593 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
594
595 if (dma_scr & STM32_DMA_SCR_DBM) {
596 if (chan->next_sg == chan->desc->num_sgs)
597 chan->next_sg = 0;
598
599 sg_req = &chan->desc->sg_req[chan->next_sg];
600
601 if (dma_scr & STM32_DMA_SCR_CT) {
602 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
603 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
604 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
605 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
606 } else {
607 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
608 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
609 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
610 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
611 }
612 }
613}
614
615static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
616{
617 if (chan->desc) {
618 if (chan->desc->cyclic) {
619 vchan_cyclic_callback(&chan->desc->vdesc);
620 chan->next_sg++;
621 stm32_dma_configure_next_sg(chan);
622 } else {
623 chan->busy = false;
624 if (chan->next_sg == chan->desc->num_sgs) {
625 list_del(&chan->desc->vdesc.node);
626 vchan_cookie_complete(&chan->desc->vdesc);
627 chan->desc = NULL;
628 }
629 stm32_dma_start_transfer(chan);
630 }
631 }
632}
633
634static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
635{
636 struct stm32_dma_chan *chan = devid;
637 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
638 u32 status, scr, sfcr;
639
640 spin_lock(&chan->vchan.lock);
641
642 status = stm32_dma_irq_status(chan);
643 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
644 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
645
646 if (status & STM32_DMA_TCI) {
647 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
648 if (scr & STM32_DMA_SCR_TCIE)
649 stm32_dma_handle_chan_done(chan);
650 status &= ~STM32_DMA_TCI;
651 }
652 if (status & STM32_DMA_HTI) {
653 stm32_dma_irq_clear(chan, STM32_DMA_HTI);
654 status &= ~STM32_DMA_HTI;
655 }
656 if (status & STM32_DMA_FEI) {
657 stm32_dma_irq_clear(chan, STM32_DMA_FEI);
658 status &= ~STM32_DMA_FEI;
659 if (sfcr & STM32_DMA_SFCR_FEIE) {
660 if (!(scr & STM32_DMA_SCR_EN))
661 dev_err(chan2dev(chan), "FIFO Error\n");
662 else
663 dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
664 }
665 }
666 if (status) {
667 stm32_dma_irq_clear(chan, status);
668 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
669 if (!(scr & STM32_DMA_SCR_EN))
670 dev_err(chan2dev(chan), "chan disabled by HW\n");
671 }
672
673 spin_unlock(&chan->vchan.lock);
674
675 return IRQ_HANDLED;
676}
677
678static void stm32_dma_issue_pending(struct dma_chan *c)
679{
680 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
681 unsigned long flags;
682
683 spin_lock_irqsave(&chan->vchan.lock, flags);
684 if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
685 dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
686 stm32_dma_start_transfer(chan);
687
688 }
689 spin_unlock_irqrestore(&chan->vchan.lock, flags);
690}
691
692static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
693 enum dma_transfer_direction direction,
694 enum dma_slave_buswidth *buswidth,
695 u32 buf_len)
696{
697 enum dma_slave_buswidth src_addr_width, dst_addr_width;
698 int src_bus_width, dst_bus_width;
699 int src_burst_size, dst_burst_size;
700 u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
701 u32 dma_scr, threshold;
702
703 src_addr_width = chan->dma_sconfig.src_addr_width;
704 dst_addr_width = chan->dma_sconfig.dst_addr_width;
705 src_maxburst = chan->dma_sconfig.src_maxburst;
706 dst_maxburst = chan->dma_sconfig.dst_maxburst;
707 threshold = chan->threshold;
708
709 switch (direction) {
710 case DMA_MEM_TO_DEV:
711 /* Set device data size */
712 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
713 if (dst_bus_width < 0)
714 return dst_bus_width;
715
716 /* Set device burst size */
717 dst_best_burst = stm32_dma_get_best_burst(buf_len,
718 dst_maxburst,
719 threshold,
720 dst_addr_width);
721
722 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
723 if (dst_burst_size < 0)
724 return dst_burst_size;
725
726 /* Set memory data size */
727 src_addr_width = stm32_dma_get_max_width(buf_len, threshold);
728 chan->mem_width = src_addr_width;
729 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
730 if (src_bus_width < 0)
731 return src_bus_width;
732
733 /* Set memory burst size */
734 src_maxburst = STM32_DMA_MAX_BURST;
735 src_best_burst = stm32_dma_get_best_burst(buf_len,
736 src_maxburst,
737 threshold,
738 src_addr_width);
739 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
740 if (src_burst_size < 0)
741 return src_burst_size;
742
743 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
744 STM32_DMA_SCR_PSIZE(dst_bus_width) |
745 STM32_DMA_SCR_MSIZE(src_bus_width) |
746 STM32_DMA_SCR_PBURST(dst_burst_size) |
747 STM32_DMA_SCR_MBURST(src_burst_size);
748
749 /* Set FIFO threshold */
750 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
751 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_FTH(threshold);
752
753 /* Set peripheral address */
754 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
755 *buswidth = dst_addr_width;
756 break;
757
758 case DMA_DEV_TO_MEM:
759 /* Set device data size */
760 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
761 if (src_bus_width < 0)
762 return src_bus_width;
763
764 /* Set device burst size */
765 src_best_burst = stm32_dma_get_best_burst(buf_len,
766 src_maxburst,
767 threshold,
768 src_addr_width);
769 chan->mem_burst = src_best_burst;
770 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
771 if (src_burst_size < 0)
772 return src_burst_size;
773
774 /* Set memory data size */
775 dst_addr_width = stm32_dma_get_max_width(buf_len, threshold);
776 chan->mem_width = dst_addr_width;
777 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
778 if (dst_bus_width < 0)
779 return dst_bus_width;
780
781 /* Set memory burst size */
782 dst_maxburst = STM32_DMA_MAX_BURST;
783 dst_best_burst = stm32_dma_get_best_burst(buf_len,
784 dst_maxburst,
785 threshold,
786 dst_addr_width);
787 chan->mem_burst = dst_best_burst;
788 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
789 if (dst_burst_size < 0)
790 return dst_burst_size;
791
792 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
793 STM32_DMA_SCR_PSIZE(src_bus_width) |
794 STM32_DMA_SCR_MSIZE(dst_bus_width) |
795 STM32_DMA_SCR_PBURST(src_burst_size) |
796 STM32_DMA_SCR_MBURST(dst_burst_size);
797
798 /* Set FIFO threshold */
799 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
800 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_FTH(threshold);
801
802 /* Set peripheral address */
803 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
804 *buswidth = chan->dma_sconfig.src_addr_width;
805 break;
806
807 default:
808 dev_err(chan2dev(chan), "Dma direction is not supported\n");
809 return -EINVAL;
810 }
811
812 stm32_dma_set_fifo_config(chan, src_best_burst, dst_best_burst);
813
814 /* Set DMA control register */
815 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
816 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
817 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
818 chan->chan_reg.dma_scr |= dma_scr;
819
820 return 0;
821}
822
823static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
824{
825 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
826}
827
828static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
829 struct dma_chan *c, struct scatterlist *sgl,
830 u32 sg_len, enum dma_transfer_direction direction,
831 unsigned long flags, void *context)
832{
833 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
834 struct stm32_dma_desc *desc;
835 struct scatterlist *sg;
836 enum dma_slave_buswidth buswidth;
837 u32 nb_data_items;
838 int i, ret;
839
840 if (!chan->config_init) {
841 dev_err(chan2dev(chan), "dma channel is not configured\n");
842 return NULL;
843 }
844
845 if (sg_len < 1) {
846 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
847 return NULL;
848 }
849
850 desc = kzalloc(struct_size(desc, sg_req, sg_len), GFP_NOWAIT);
851 if (!desc)
852 return NULL;
853
854 /* Set peripheral flow controller */
855 if (chan->dma_sconfig.device_fc)
856 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
857 else
858 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
859
860 for_each_sg(sgl, sg, sg_len, i) {
861 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth,
862 sg_dma_len(sg));
863 if (ret < 0)
864 goto err;
865
866 desc->sg_req[i].len = sg_dma_len(sg);
867
868 nb_data_items = desc->sg_req[i].len / buswidth;
869 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
870 dev_err(chan2dev(chan), "nb items not supported\n");
871 goto err;
872 }
873
874 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
875 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
876 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
877 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
878 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
879 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
880 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
881 }
882
883 desc->num_sgs = sg_len;
884 desc->cyclic = false;
885
886 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
887
888err:
889 kfree(desc);
890 return NULL;
891}
892
893static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
894 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
895 size_t period_len, enum dma_transfer_direction direction,
896 unsigned long flags)
897{
898 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
899 struct stm32_dma_desc *desc;
900 enum dma_slave_buswidth buswidth;
901 u32 num_periods, nb_data_items;
902 int i, ret;
903
904 if (!buf_len || !period_len) {
905 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
906 return NULL;
907 }
908
909 if (!chan->config_init) {
910 dev_err(chan2dev(chan), "dma channel is not configured\n");
911 return NULL;
912 }
913
914 if (buf_len % period_len) {
915 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
916 return NULL;
917 }
918
919 /*
920 * We allow to take more number of requests till DMA is
921 * not started. The driver will loop over all requests.
922 * Once DMA is started then new requests can be queued only after
923 * terminating the DMA.
924 */
925 if (chan->busy) {
926 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
927 return NULL;
928 }
929
930 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len);
931 if (ret < 0)
932 return NULL;
933
934 nb_data_items = period_len / buswidth;
935 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
936 dev_err(chan2dev(chan), "number of items not supported\n");
937 return NULL;
938 }
939
940 /* Enable Circular mode or double buffer mode */
941 if (buf_len == period_len)
942 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
943 else
944 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
945
946 /* Clear periph ctrl if client set it */
947 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
948
949 num_periods = buf_len / period_len;
950
951 desc = kzalloc(struct_size(desc, sg_req, num_periods), GFP_NOWAIT);
952 if (!desc)
953 return NULL;
954
955 for (i = 0; i < num_periods; i++) {
956 desc->sg_req[i].len = period_len;
957
958 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
959 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
960 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
961 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
962 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
963 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
964 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
965 buf_addr += period_len;
966 }
967
968 desc->num_sgs = num_periods;
969 desc->cyclic = true;
970
971 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
972}
973
974static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
975 struct dma_chan *c, dma_addr_t dest,
976 dma_addr_t src, size_t len, unsigned long flags)
977{
978 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
979 enum dma_slave_buswidth max_width;
980 struct stm32_dma_desc *desc;
981 size_t xfer_count, offset;
982 u32 num_sgs, best_burst, dma_burst, threshold;
983 int i;
984
985 num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
986 desc = kzalloc(struct_size(desc, sg_req, num_sgs), GFP_NOWAIT);
987 if (!desc)
988 return NULL;
989
990 threshold = chan->threshold;
991
992 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
993 xfer_count = min_t(size_t, len - offset,
994 STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
995
996 /* Compute best burst size */
997 max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
998 best_burst = stm32_dma_get_best_burst(len, STM32_DMA_MAX_BURST,
999 threshold, max_width);
1000 dma_burst = stm32_dma_get_burst(chan, best_burst);
1001
1002 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1003 desc->sg_req[i].chan_reg.dma_scr =
1004 STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
1005 STM32_DMA_SCR_PBURST(dma_burst) |
1006 STM32_DMA_SCR_MBURST(dma_burst) |
1007 STM32_DMA_SCR_MINC |
1008 STM32_DMA_SCR_PINC |
1009 STM32_DMA_SCR_TCIE |
1010 STM32_DMA_SCR_TEIE;
1011 desc->sg_req[i].chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
1012 desc->sg_req[i].chan_reg.dma_sfcr |=
1013 STM32_DMA_SFCR_FTH(threshold);
1014 desc->sg_req[i].chan_reg.dma_spar = src + offset;
1015 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
1016 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
1017 desc->sg_req[i].len = xfer_count;
1018 }
1019
1020 desc->num_sgs = num_sgs;
1021 desc->cyclic = false;
1022
1023 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1024}
1025
1026static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
1027{
1028 u32 dma_scr, width, ndtr;
1029 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1030
1031 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
1032 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
1033 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
1034
1035 return ndtr << width;
1036}
1037
1038/**
1039 * stm32_dma_is_current_sg - check that expected sg_req is currently transferred
1040 * @chan: dma channel
1041 *
1042 * This function called when IRQ are disable, checks that the hardware has not
1043 * switched on the next transfer in double buffer mode. The test is done by
1044 * comparing the next_sg memory address with the hardware related register
1045 * (based on CT bit value).
1046 *
1047 * Returns true if expected current transfer is still running or double
1048 * buffer mode is not activated.
1049 */
1050static bool stm32_dma_is_current_sg(struct stm32_dma_chan *chan)
1051{
1052 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1053 struct stm32_dma_sg_req *sg_req;
1054 u32 dma_scr, dma_smar, id;
1055
1056 id = chan->id;
1057 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
1058
1059 if (!(dma_scr & STM32_DMA_SCR_DBM))
1060 return true;
1061
1062 sg_req = &chan->desc->sg_req[chan->next_sg];
1063
1064 if (dma_scr & STM32_DMA_SCR_CT) {
1065 dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(id));
1066 return (dma_smar == sg_req->chan_reg.dma_sm0ar);
1067 }
1068
1069 dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(id));
1070
1071 return (dma_smar == sg_req->chan_reg.dma_sm1ar);
1072}
1073
1074static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
1075 struct stm32_dma_desc *desc,
1076 u32 next_sg)
1077{
1078 u32 modulo, burst_size;
1079 u32 residue;
1080 u32 n_sg = next_sg;
1081 struct stm32_dma_sg_req *sg_req = &chan->desc->sg_req[chan->next_sg];
1082 int i;
1083
1084 /*
1085 * Calculate the residue means compute the descriptors
1086 * information:
1087 * - the sg_req currently transferred
1088 * - the Hardware remaining position in this sg (NDTR bits field).
1089 *
1090 * A race condition may occur if DMA is running in cyclic or double
1091 * buffer mode, since the DMA register are automatically reloaded at end
1092 * of period transfer. The hardware may have switched to the next
1093 * transfer (CT bit updated) just before the position (SxNDTR reg) is
1094 * read.
1095 * In this case the SxNDTR reg could (or not) correspond to the new
1096 * transfer position, and not the expected one.
1097 * The strategy implemented in the stm32 driver is to:
1098 * - read the SxNDTR register
1099 * - crosscheck that hardware is still in current transfer.
1100 * In case of switch, we can assume that the DMA is at the beginning of
1101 * the next transfer. So we approximate the residue in consequence, by
1102 * pointing on the beginning of next transfer.
1103 *
1104 * This race condition doesn't apply for none cyclic mode, as double
1105 * buffer is not used. In such situation registers are updated by the
1106 * software.
1107 */
1108
1109 residue = stm32_dma_get_remaining_bytes(chan);
1110
1111 if (!stm32_dma_is_current_sg(chan)) {
1112 n_sg++;
1113 if (n_sg == chan->desc->num_sgs)
1114 n_sg = 0;
1115 residue = sg_req->len;
1116 }
1117
1118 /*
1119 * In cyclic mode, for the last period, residue = remaining bytes
1120 * from NDTR,
1121 * else for all other periods in cyclic mode, and in sg mode,
1122 * residue = remaining bytes from NDTR + remaining
1123 * periods/sg to be transferred
1124 */
1125 if (!chan->desc->cyclic || n_sg != 0)
1126 for (i = n_sg; i < desc->num_sgs; i++)
1127 residue += desc->sg_req[i].len;
1128
1129 if (!chan->mem_burst)
1130 return residue;
1131
1132 burst_size = chan->mem_burst * chan->mem_width;
1133 modulo = residue % burst_size;
1134 if (modulo)
1135 residue = residue - modulo + burst_size;
1136
1137 return residue;
1138}
1139
1140static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
1141 dma_cookie_t cookie,
1142 struct dma_tx_state *state)
1143{
1144 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1145 struct virt_dma_desc *vdesc;
1146 enum dma_status status;
1147 unsigned long flags;
1148 u32 residue = 0;
1149
1150 status = dma_cookie_status(c, cookie, state);
1151 if (status == DMA_COMPLETE || !state)
1152 return status;
1153
1154 spin_lock_irqsave(&chan->vchan.lock, flags);
1155 vdesc = vchan_find_desc(&chan->vchan, cookie);
1156 if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1157 residue = stm32_dma_desc_residue(chan, chan->desc,
1158 chan->next_sg);
1159 else if (vdesc)
1160 residue = stm32_dma_desc_residue(chan,
1161 to_stm32_dma_desc(vdesc), 0);
1162 dma_set_residue(state, residue);
1163
1164 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1165
1166 return status;
1167}
1168
1169static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
1170{
1171 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1172 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1173 int ret;
1174
1175 chan->config_init = false;
1176
1177 ret = pm_runtime_get_sync(dmadev->ddev.dev);
1178 if (ret < 0)
1179 return ret;
1180
1181 ret = stm32_dma_disable_chan(chan);
1182 if (ret < 0)
1183 pm_runtime_put(dmadev->ddev.dev);
1184
1185 return ret;
1186}
1187
1188static void stm32_dma_free_chan_resources(struct dma_chan *c)
1189{
1190 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1191 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1192 unsigned long flags;
1193
1194 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1195
1196 if (chan->busy) {
1197 spin_lock_irqsave(&chan->vchan.lock, flags);
1198 stm32_dma_stop(chan);
1199 chan->desc = NULL;
1200 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1201 }
1202
1203 pm_runtime_put(dmadev->ddev.dev);
1204
1205 vchan_free_chan_resources(to_virt_chan(c));
1206}
1207
1208static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
1209{
1210 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
1211}
1212
1213static void stm32_dma_set_config(struct stm32_dma_chan *chan,
1214 struct stm32_dma_cfg *cfg)
1215{
1216 stm32_dma_clear_reg(&chan->chan_reg);
1217
1218 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
1219 chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
1220
1221 /* Enable Interrupts */
1222 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
1223
1224 chan->threshold = STM32_DMA_THRESHOLD_FTR_GET(cfg->features);
1225}
1226
1227static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
1228 struct of_dma *ofdma)
1229{
1230 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
1231 struct device *dev = dmadev->ddev.dev;
1232 struct stm32_dma_cfg cfg;
1233 struct stm32_dma_chan *chan;
1234 struct dma_chan *c;
1235
1236 if (dma_spec->args_count < 4) {
1237 dev_err(dev, "Bad number of cells\n");
1238 return NULL;
1239 }
1240
1241 cfg.channel_id = dma_spec->args[0];
1242 cfg.request_line = dma_spec->args[1];
1243 cfg.stream_config = dma_spec->args[2];
1244 cfg.features = dma_spec->args[3];
1245
1246 if (cfg.channel_id >= STM32_DMA_MAX_CHANNELS ||
1247 cfg.request_line >= STM32_DMA_MAX_REQUEST_ID) {
1248 dev_err(dev, "Bad channel and/or request id\n");
1249 return NULL;
1250 }
1251
1252 chan = &dmadev->chan[cfg.channel_id];
1253
1254 c = dma_get_slave_channel(&chan->vchan.chan);
1255 if (!c) {
1256 dev_err(dev, "No more channels available\n");
1257 return NULL;
1258 }
1259
1260 stm32_dma_set_config(chan, &cfg);
1261
1262 return c;
1263}
1264
1265static const struct of_device_id stm32_dma_of_match[] = {
1266 { .compatible = "st,stm32-dma", },
1267 { /* sentinel */ },
1268};
1269MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1270
1271static int stm32_dma_probe(struct platform_device *pdev)
1272{
1273 struct stm32_dma_chan *chan;
1274 struct stm32_dma_device *dmadev;
1275 struct dma_device *dd;
1276 const struct of_device_id *match;
1277 struct resource *res;
1278 int i, ret;
1279
1280 match = of_match_device(stm32_dma_of_match, &pdev->dev);
1281 if (!match) {
1282 dev_err(&pdev->dev, "Error: No device match found\n");
1283 return -ENODEV;
1284 }
1285
1286 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1287 if (!dmadev)
1288 return -ENOMEM;
1289
1290 dd = &dmadev->ddev;
1291
1292 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1293 dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1294 if (IS_ERR(dmadev->base))
1295 return PTR_ERR(dmadev->base);
1296
1297 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1298 if (IS_ERR(dmadev->clk)) {
1299 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1300 return PTR_ERR(dmadev->clk);
1301 }
1302
1303 ret = clk_prepare_enable(dmadev->clk);
1304 if (ret < 0) {
1305 dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
1306 return ret;
1307 }
1308
1309 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1310 "st,mem2mem");
1311
1312 dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
1313 if (!IS_ERR(dmadev->rst)) {
1314 reset_control_assert(dmadev->rst);
1315 udelay(2);
1316 reset_control_deassert(dmadev->rst);
1317 }
1318
1319 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1320 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1321 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1322 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1323 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1324 dd->device_tx_status = stm32_dma_tx_status;
1325 dd->device_issue_pending = stm32_dma_issue_pending;
1326 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1327 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1328 dd->device_config = stm32_dma_slave_config;
1329 dd->device_terminate_all = stm32_dma_terminate_all;
1330 dd->device_synchronize = stm32_dma_synchronize;
1331 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1332 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1333 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1334 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1335 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1336 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1337 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1338 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1339 dd->max_burst = STM32_DMA_MAX_BURST;
1340 dd->dev = &pdev->dev;
1341 INIT_LIST_HEAD(&dd->channels);
1342
1343 if (dmadev->mem2mem) {
1344 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1345 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1346 dd->directions |= BIT(DMA_MEM_TO_MEM);
1347 }
1348
1349 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1350 chan = &dmadev->chan[i];
1351 chan->id = i;
1352 chan->vchan.desc_free = stm32_dma_desc_free;
1353 vchan_init(&chan->vchan, dd);
1354 }
1355
1356 ret = dma_async_device_register(dd);
1357 if (ret)
1358 goto clk_free;
1359
1360 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1361 chan = &dmadev->chan[i];
1362 ret = platform_get_irq(pdev, i);
1363 if (ret < 0)
1364 goto err_unregister;
1365 chan->irq = ret;
1366
1367 ret = devm_request_irq(&pdev->dev, chan->irq,
1368 stm32_dma_chan_irq, 0,
1369 dev_name(chan2dev(chan)), chan);
1370 if (ret) {
1371 dev_err(&pdev->dev,
1372 "request_irq failed with err %d channel %d\n",
1373 ret, i);
1374 goto err_unregister;
1375 }
1376 }
1377
1378 ret = of_dma_controller_register(pdev->dev.of_node,
1379 stm32_dma_of_xlate, dmadev);
1380 if (ret < 0) {
1381 dev_err(&pdev->dev,
1382 "STM32 DMA DMA OF registration failed %d\n", ret);
1383 goto err_unregister;
1384 }
1385
1386 platform_set_drvdata(pdev, dmadev);
1387
1388 pm_runtime_set_active(&pdev->dev);
1389 pm_runtime_enable(&pdev->dev);
1390 pm_runtime_get_noresume(&pdev->dev);
1391 pm_runtime_put(&pdev->dev);
1392
1393 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1394
1395 return 0;
1396
1397err_unregister:
1398 dma_async_device_unregister(dd);
1399clk_free:
1400 clk_disable_unprepare(dmadev->clk);
1401
1402 return ret;
1403}
1404
1405#ifdef CONFIG_PM
1406static int stm32_dma_runtime_suspend(struct device *dev)
1407{
1408 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1409
1410 clk_disable_unprepare(dmadev->clk);
1411
1412 return 0;
1413}
1414
1415static int stm32_dma_runtime_resume(struct device *dev)
1416{
1417 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1418 int ret;
1419
1420 ret = clk_prepare_enable(dmadev->clk);
1421 if (ret) {
1422 dev_err(dev, "failed to prepare_enable clock\n");
1423 return ret;
1424 }
1425
1426 return 0;
1427}
1428#endif
1429
1430static const struct dev_pm_ops stm32_dma_pm_ops = {
1431 SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend,
1432 stm32_dma_runtime_resume, NULL)
1433};
1434
1435static struct platform_driver stm32_dma_driver = {
1436 .driver = {
1437 .name = "stm32-dma",
1438 .of_match_table = stm32_dma_of_match,
1439 .pm = &stm32_dma_pm_ops,
1440 },
1441};
1442
1443static int __init stm32_dma_init(void)
1444{
1445 return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
1446}
1447subsys_initcall(stm32_dma_init);