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1/*
2 * Driver for STM32 DMA controller
3 *
4 * Inspired by dma-jz4740.c and tegra20-apb-dma.c
5 *
6 * Copyright (C) M'boumba Cedric Madianga 2015
7 * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
8 * Pierre-Yves Mordret <pierre-yves.mordret@st.com>
9 *
10 * License terms: GNU General Public License (GPL), version 2
11 */
12
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/jiffies.h>
20#include <linux/list.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/of_device.h>
24#include <linux/of_dma.h>
25#include <linux/platform_device.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 struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs)
247{
248 return kzalloc(sizeof(struct stm32_dma_desc) +
249 sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT);
250}
251
252static int stm32_dma_get_width(struct stm32_dma_chan *chan,
253 enum dma_slave_buswidth width)
254{
255 switch (width) {
256 case DMA_SLAVE_BUSWIDTH_1_BYTE:
257 return STM32_DMA_BYTE;
258 case DMA_SLAVE_BUSWIDTH_2_BYTES:
259 return STM32_DMA_HALF_WORD;
260 case DMA_SLAVE_BUSWIDTH_4_BYTES:
261 return STM32_DMA_WORD;
262 default:
263 dev_err(chan2dev(chan), "Dma bus width not supported\n");
264 return -EINVAL;
265 }
266}
267
268static enum dma_slave_buswidth stm32_dma_get_max_width(u32 buf_len,
269 u32 threshold)
270{
271 enum dma_slave_buswidth max_width;
272
273 if (threshold == STM32_DMA_FIFO_THRESHOLD_FULL)
274 max_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
275 else
276 max_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
277
278 while ((buf_len < max_width || buf_len % max_width) &&
279 max_width > DMA_SLAVE_BUSWIDTH_1_BYTE)
280 max_width = max_width >> 1;
281
282 return max_width;
283}
284
285static bool stm32_dma_fifo_threshold_is_allowed(u32 burst, u32 threshold,
286 enum dma_slave_buswidth width)
287{
288 u32 remaining;
289
290 if (width != DMA_SLAVE_BUSWIDTH_UNDEFINED) {
291 if (burst != 0) {
292 /*
293 * If number of beats fit in several whole bursts
294 * this configuration is allowed.
295 */
296 remaining = ((STM32_DMA_FIFO_SIZE / width) *
297 (threshold + 1) / 4) % burst;
298
299 if (remaining == 0)
300 return true;
301 } else {
302 return true;
303 }
304 }
305
306 return false;
307}
308
309static bool stm32_dma_is_burst_possible(u32 buf_len, u32 threshold)
310{
311 switch (threshold) {
312 case STM32_DMA_FIFO_THRESHOLD_FULL:
313 if (buf_len >= STM32_DMA_MAX_BURST)
314 return true;
315 else
316 return false;
317 case STM32_DMA_FIFO_THRESHOLD_HALFFULL:
318 if (buf_len >= STM32_DMA_MAX_BURST / 2)
319 return true;
320 else
321 return false;
322 default:
323 return false;
324 }
325}
326
327static u32 stm32_dma_get_best_burst(u32 buf_len, u32 max_burst, u32 threshold,
328 enum dma_slave_buswidth width)
329{
330 u32 best_burst = max_burst;
331
332 if (best_burst == 1 || !stm32_dma_is_burst_possible(buf_len, threshold))
333 return 0;
334
335 while ((buf_len < best_burst * width && best_burst > 1) ||
336 !stm32_dma_fifo_threshold_is_allowed(best_burst, threshold,
337 width)) {
338 if (best_burst > STM32_DMA_MIN_BURST)
339 best_burst = best_burst >> 1;
340 else
341 best_burst = 0;
342 }
343
344 return best_burst;
345}
346
347static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
348{
349 switch (maxburst) {
350 case 0:
351 case 1:
352 return STM32_DMA_BURST_SINGLE;
353 case 4:
354 return STM32_DMA_BURST_INCR4;
355 case 8:
356 return STM32_DMA_BURST_INCR8;
357 case 16:
358 return STM32_DMA_BURST_INCR16;
359 default:
360 dev_err(chan2dev(chan), "Dma burst size not supported\n");
361 return -EINVAL;
362 }
363}
364
365static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
366 u32 src_burst, u32 dst_burst)
367{
368 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
369 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
370
371 if (!src_burst && !dst_burst) {
372 /* Using direct mode */
373 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
374 } else {
375 /* Using FIFO mode */
376 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
377 }
378}
379
380static int stm32_dma_slave_config(struct dma_chan *c,
381 struct dma_slave_config *config)
382{
383 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
384
385 memcpy(&chan->dma_sconfig, config, sizeof(*config));
386
387 chan->config_init = true;
388
389 return 0;
390}
391
392static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
393{
394 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
395 u32 flags, dma_isr;
396
397 /*
398 * Read "flags" from DMA_xISR register corresponding to the selected
399 * DMA channel at the correct bit offset inside that register.
400 *
401 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
402 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
403 */
404
405 if (chan->id & 4)
406 dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR);
407 else
408 dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR);
409
410 flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
411
412 return flags & STM32_DMA_MASKI;
413}
414
415static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
416{
417 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
418 u32 dma_ifcr;
419
420 /*
421 * Write "flags" to the DMA_xIFCR register corresponding to the selected
422 * DMA channel at the correct bit offset inside that register.
423 *
424 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
425 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
426 */
427 flags &= STM32_DMA_MASKI;
428 dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
429
430 if (chan->id & 4)
431 stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr);
432 else
433 stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr);
434}
435
436static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
437{
438 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
439 unsigned long timeout = jiffies + msecs_to_jiffies(5000);
440 u32 dma_scr, id;
441
442 id = chan->id;
443 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
444
445 if (dma_scr & STM32_DMA_SCR_EN) {
446 dma_scr &= ~STM32_DMA_SCR_EN;
447 stm32_dma_write(dmadev, STM32_DMA_SCR(id), dma_scr);
448
449 do {
450 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
451 dma_scr &= STM32_DMA_SCR_EN;
452 if (!dma_scr)
453 break;
454
455 if (time_after_eq(jiffies, timeout)) {
456 dev_err(chan2dev(chan), "%s: timeout!\n",
457 __func__);
458 return -EBUSY;
459 }
460 cond_resched();
461 } while (1);
462 }
463
464 return 0;
465}
466
467static void stm32_dma_stop(struct stm32_dma_chan *chan)
468{
469 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
470 u32 dma_scr, dma_sfcr, status;
471 int ret;
472
473 /* Disable interrupts */
474 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
475 dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
476 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
477 dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
478 dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
479 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
480
481 /* Disable DMA */
482 ret = stm32_dma_disable_chan(chan);
483 if (ret < 0)
484 return;
485
486 /* Clear interrupt status if it is there */
487 status = stm32_dma_irq_status(chan);
488 if (status) {
489 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
490 __func__, status);
491 stm32_dma_irq_clear(chan, status);
492 }
493
494 chan->busy = false;
495}
496
497static int stm32_dma_terminate_all(struct dma_chan *c)
498{
499 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
500 unsigned long flags;
501 LIST_HEAD(head);
502
503 spin_lock_irqsave(&chan->vchan.lock, flags);
504
505 if (chan->busy) {
506 stm32_dma_stop(chan);
507 chan->desc = NULL;
508 }
509
510 vchan_get_all_descriptors(&chan->vchan, &head);
511 spin_unlock_irqrestore(&chan->vchan.lock, flags);
512 vchan_dma_desc_free_list(&chan->vchan, &head);
513
514 return 0;
515}
516
517static void stm32_dma_synchronize(struct dma_chan *c)
518{
519 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
520
521 vchan_synchronize(&chan->vchan);
522}
523
524static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
525{
526 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
527 u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
528 u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
529 u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
530 u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
531 u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
532 u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
533
534 dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr);
535 dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr);
536 dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar);
537 dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
538 dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
539 dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
540}
541
542static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan);
543
544static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
545{
546 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
547 struct virt_dma_desc *vdesc;
548 struct stm32_dma_sg_req *sg_req;
549 struct stm32_dma_chan_reg *reg;
550 u32 status;
551 int ret;
552
553 ret = stm32_dma_disable_chan(chan);
554 if (ret < 0)
555 return;
556
557 if (!chan->desc) {
558 vdesc = vchan_next_desc(&chan->vchan);
559 if (!vdesc)
560 return;
561
562 chan->desc = to_stm32_dma_desc(vdesc);
563 chan->next_sg = 0;
564 }
565
566 if (chan->next_sg == chan->desc->num_sgs)
567 chan->next_sg = 0;
568
569 sg_req = &chan->desc->sg_req[chan->next_sg];
570 reg = &sg_req->chan_reg;
571
572 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
573 stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
574 stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
575 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
576 stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
577 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
578
579 chan->next_sg++;
580
581 /* Clear interrupt status if it is there */
582 status = stm32_dma_irq_status(chan);
583 if (status)
584 stm32_dma_irq_clear(chan, status);
585
586 if (chan->desc->cyclic)
587 stm32_dma_configure_next_sg(chan);
588
589 stm32_dma_dump_reg(chan);
590
591 /* Start DMA */
592 reg->dma_scr |= STM32_DMA_SCR_EN;
593 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
594
595 chan->busy = true;
596
597 dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);
598}
599
600static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
601{
602 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
603 struct stm32_dma_sg_req *sg_req;
604 u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
605
606 id = chan->id;
607 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
608
609 if (dma_scr & STM32_DMA_SCR_DBM) {
610 if (chan->next_sg == chan->desc->num_sgs)
611 chan->next_sg = 0;
612
613 sg_req = &chan->desc->sg_req[chan->next_sg];
614
615 if (dma_scr & STM32_DMA_SCR_CT) {
616 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
617 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
618 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
619 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
620 } else {
621 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
622 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
623 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
624 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
625 }
626 }
627}
628
629static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
630{
631 if (chan->desc) {
632 if (chan->desc->cyclic) {
633 vchan_cyclic_callback(&chan->desc->vdesc);
634 chan->next_sg++;
635 stm32_dma_configure_next_sg(chan);
636 } else {
637 chan->busy = false;
638 if (chan->next_sg == chan->desc->num_sgs) {
639 list_del(&chan->desc->vdesc.node);
640 vchan_cookie_complete(&chan->desc->vdesc);
641 chan->desc = NULL;
642 }
643 stm32_dma_start_transfer(chan);
644 }
645 }
646}
647
648static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
649{
650 struct stm32_dma_chan *chan = devid;
651 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
652 u32 status, scr;
653
654 spin_lock(&chan->vchan.lock);
655
656 status = stm32_dma_irq_status(chan);
657 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
658
659 if (status & STM32_DMA_TCI) {
660 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
661 if (scr & STM32_DMA_SCR_TCIE)
662 stm32_dma_handle_chan_done(chan);
663 status &= ~STM32_DMA_TCI;
664 }
665 if (status & STM32_DMA_HTI) {
666 stm32_dma_irq_clear(chan, STM32_DMA_HTI);
667 status &= ~STM32_DMA_HTI;
668 }
669 if (status & STM32_DMA_FEI) {
670 stm32_dma_irq_clear(chan, STM32_DMA_FEI);
671 status &= ~STM32_DMA_FEI;
672 if (!(scr & STM32_DMA_SCR_EN))
673 dev_err(chan2dev(chan), "FIFO Error\n");
674 else
675 dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
676 }
677 if (status) {
678 stm32_dma_irq_clear(chan, status);
679 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
680 if (!(scr & STM32_DMA_SCR_EN))
681 dev_err(chan2dev(chan), "chan disabled by HW\n");
682 }
683
684 spin_unlock(&chan->vchan.lock);
685
686 return IRQ_HANDLED;
687}
688
689static void stm32_dma_issue_pending(struct dma_chan *c)
690{
691 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
692 unsigned long flags;
693
694 spin_lock_irqsave(&chan->vchan.lock, flags);
695 if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
696 dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
697 stm32_dma_start_transfer(chan);
698
699 }
700 spin_unlock_irqrestore(&chan->vchan.lock, flags);
701}
702
703static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
704 enum dma_transfer_direction direction,
705 enum dma_slave_buswidth *buswidth,
706 u32 buf_len)
707{
708 enum dma_slave_buswidth src_addr_width, dst_addr_width;
709 int src_bus_width, dst_bus_width;
710 int src_burst_size, dst_burst_size;
711 u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
712 u32 dma_scr, threshold;
713
714 src_addr_width = chan->dma_sconfig.src_addr_width;
715 dst_addr_width = chan->dma_sconfig.dst_addr_width;
716 src_maxburst = chan->dma_sconfig.src_maxburst;
717 dst_maxburst = chan->dma_sconfig.dst_maxburst;
718 threshold = chan->threshold;
719
720 switch (direction) {
721 case DMA_MEM_TO_DEV:
722 /* Set device data size */
723 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
724 if (dst_bus_width < 0)
725 return dst_bus_width;
726
727 /* Set device burst size */
728 dst_best_burst = stm32_dma_get_best_burst(buf_len,
729 dst_maxburst,
730 threshold,
731 dst_addr_width);
732
733 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
734 if (dst_burst_size < 0)
735 return dst_burst_size;
736
737 /* Set memory data size */
738 src_addr_width = stm32_dma_get_max_width(buf_len, threshold);
739 chan->mem_width = src_addr_width;
740 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
741 if (src_bus_width < 0)
742 return src_bus_width;
743
744 /* Set memory burst size */
745 src_maxburst = STM32_DMA_MAX_BURST;
746 src_best_burst = stm32_dma_get_best_burst(buf_len,
747 src_maxburst,
748 threshold,
749 src_addr_width);
750 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
751 if (src_burst_size < 0)
752 return src_burst_size;
753
754 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
755 STM32_DMA_SCR_PSIZE(dst_bus_width) |
756 STM32_DMA_SCR_MSIZE(src_bus_width) |
757 STM32_DMA_SCR_PBURST(dst_burst_size) |
758 STM32_DMA_SCR_MBURST(src_burst_size);
759
760 /* Set FIFO threshold */
761 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
762 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_FTH(threshold);
763
764 /* Set peripheral address */
765 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
766 *buswidth = dst_addr_width;
767 break;
768
769 case DMA_DEV_TO_MEM:
770 /* Set device data size */
771 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
772 if (src_bus_width < 0)
773 return src_bus_width;
774
775 /* Set device burst size */
776 src_best_burst = stm32_dma_get_best_burst(buf_len,
777 src_maxburst,
778 threshold,
779 src_addr_width);
780 chan->mem_burst = src_best_burst;
781 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
782 if (src_burst_size < 0)
783 return src_burst_size;
784
785 /* Set memory data size */
786 dst_addr_width = stm32_dma_get_max_width(buf_len, threshold);
787 chan->mem_width = dst_addr_width;
788 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
789 if (dst_bus_width < 0)
790 return dst_bus_width;
791
792 /* Set memory burst size */
793 dst_maxburst = STM32_DMA_MAX_BURST;
794 dst_best_burst = stm32_dma_get_best_burst(buf_len,
795 dst_maxburst,
796 threshold,
797 dst_addr_width);
798 chan->mem_burst = dst_best_burst;
799 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
800 if (dst_burst_size < 0)
801 return dst_burst_size;
802
803 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
804 STM32_DMA_SCR_PSIZE(src_bus_width) |
805 STM32_DMA_SCR_MSIZE(dst_bus_width) |
806 STM32_DMA_SCR_PBURST(src_burst_size) |
807 STM32_DMA_SCR_MBURST(dst_burst_size);
808
809 /* Set FIFO threshold */
810 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
811 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_FTH(threshold);
812
813 /* Set peripheral address */
814 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
815 *buswidth = chan->dma_sconfig.src_addr_width;
816 break;
817
818 default:
819 dev_err(chan2dev(chan), "Dma direction is not supported\n");
820 return -EINVAL;
821 }
822
823 stm32_dma_set_fifo_config(chan, src_best_burst, dst_best_burst);
824
825 /* Set DMA control register */
826 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
827 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
828 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
829 chan->chan_reg.dma_scr |= dma_scr;
830
831 return 0;
832}
833
834static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
835{
836 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
837}
838
839static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
840 struct dma_chan *c, struct scatterlist *sgl,
841 u32 sg_len, enum dma_transfer_direction direction,
842 unsigned long flags, void *context)
843{
844 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
845 struct stm32_dma_desc *desc;
846 struct scatterlist *sg;
847 enum dma_slave_buswidth buswidth;
848 u32 nb_data_items;
849 int i, ret;
850
851 if (!chan->config_init) {
852 dev_err(chan2dev(chan), "dma channel is not configured\n");
853 return NULL;
854 }
855
856 if (sg_len < 1) {
857 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
858 return NULL;
859 }
860
861 desc = stm32_dma_alloc_desc(sg_len);
862 if (!desc)
863 return NULL;
864
865 /* Set peripheral flow controller */
866 if (chan->dma_sconfig.device_fc)
867 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
868 else
869 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
870
871 for_each_sg(sgl, sg, sg_len, i) {
872 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth,
873 sg_dma_len(sg));
874 if (ret < 0)
875 goto err;
876
877 desc->sg_req[i].len = sg_dma_len(sg);
878
879 nb_data_items = desc->sg_req[i].len / buswidth;
880 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
881 dev_err(chan2dev(chan), "nb items not supported\n");
882 goto err;
883 }
884
885 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
886 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
887 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
888 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
889 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
890 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
891 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
892 }
893
894 desc->num_sgs = sg_len;
895 desc->cyclic = false;
896
897 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
898
899err:
900 kfree(desc);
901 return NULL;
902}
903
904static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
905 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
906 size_t period_len, enum dma_transfer_direction direction,
907 unsigned long flags)
908{
909 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
910 struct stm32_dma_desc *desc;
911 enum dma_slave_buswidth buswidth;
912 u32 num_periods, nb_data_items;
913 int i, ret;
914
915 if (!buf_len || !period_len) {
916 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
917 return NULL;
918 }
919
920 if (!chan->config_init) {
921 dev_err(chan2dev(chan), "dma channel is not configured\n");
922 return NULL;
923 }
924
925 if (buf_len % period_len) {
926 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
927 return NULL;
928 }
929
930 /*
931 * We allow to take more number of requests till DMA is
932 * not started. The driver will loop over all requests.
933 * Once DMA is started then new requests can be queued only after
934 * terminating the DMA.
935 */
936 if (chan->busy) {
937 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
938 return NULL;
939 }
940
941 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len);
942 if (ret < 0)
943 return NULL;
944
945 nb_data_items = period_len / buswidth;
946 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
947 dev_err(chan2dev(chan), "number of items not supported\n");
948 return NULL;
949 }
950
951 /* Enable Circular mode or double buffer mode */
952 if (buf_len == period_len)
953 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
954 else
955 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
956
957 /* Clear periph ctrl if client set it */
958 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
959
960 num_periods = buf_len / period_len;
961
962 desc = stm32_dma_alloc_desc(num_periods);
963 if (!desc)
964 return NULL;
965
966 for (i = 0; i < num_periods; i++) {
967 desc->sg_req[i].len = period_len;
968
969 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
970 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
971 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
972 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
973 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
974 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
975 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
976 buf_addr += period_len;
977 }
978
979 desc->num_sgs = num_periods;
980 desc->cyclic = true;
981
982 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
983}
984
985static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
986 struct dma_chan *c, dma_addr_t dest,
987 dma_addr_t src, size_t len, unsigned long flags)
988{
989 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
990 enum dma_slave_buswidth max_width;
991 struct stm32_dma_desc *desc;
992 size_t xfer_count, offset;
993 u32 num_sgs, best_burst, dma_burst, threshold;
994 int i;
995
996 num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
997 desc = stm32_dma_alloc_desc(num_sgs);
998 if (!desc)
999 return NULL;
1000
1001 threshold = chan->threshold;
1002
1003 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
1004 xfer_count = min_t(size_t, len - offset,
1005 STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1006
1007 /* Compute best burst size */
1008 max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1009 best_burst = stm32_dma_get_best_burst(len, STM32_DMA_MAX_BURST,
1010 threshold, max_width);
1011 dma_burst = stm32_dma_get_burst(chan, best_burst);
1012
1013 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1014 desc->sg_req[i].chan_reg.dma_scr =
1015 STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
1016 STM32_DMA_SCR_PBURST(dma_burst) |
1017 STM32_DMA_SCR_MBURST(dma_burst) |
1018 STM32_DMA_SCR_MINC |
1019 STM32_DMA_SCR_PINC |
1020 STM32_DMA_SCR_TCIE |
1021 STM32_DMA_SCR_TEIE;
1022 desc->sg_req[i].chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
1023 desc->sg_req[i].chan_reg.dma_sfcr |=
1024 STM32_DMA_SFCR_FTH(threshold);
1025 desc->sg_req[i].chan_reg.dma_spar = src + offset;
1026 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
1027 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
1028 desc->sg_req[i].len = xfer_count;
1029 }
1030
1031 desc->num_sgs = num_sgs;
1032 desc->cyclic = false;
1033
1034 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1035}
1036
1037static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
1038{
1039 u32 dma_scr, width, ndtr;
1040 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1041
1042 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
1043 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
1044 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
1045
1046 return ndtr << width;
1047}
1048
1049static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
1050 struct stm32_dma_desc *desc,
1051 u32 next_sg)
1052{
1053 u32 modulo, burst_size;
1054 u32 residue = 0;
1055 int i;
1056
1057 /*
1058 * In cyclic mode, for the last period, residue = remaining bytes from
1059 * NDTR
1060 */
1061 if (chan->desc->cyclic && next_sg == 0) {
1062 residue = stm32_dma_get_remaining_bytes(chan);
1063 goto end;
1064 }
1065
1066 /*
1067 * For all other periods in cyclic mode, and in sg mode,
1068 * residue = remaining bytes from NDTR + remaining periods/sg to be
1069 * transferred
1070 */
1071 for (i = next_sg; i < desc->num_sgs; i++)
1072 residue += desc->sg_req[i].len;
1073 residue += stm32_dma_get_remaining_bytes(chan);
1074
1075end:
1076 if (!chan->mem_burst)
1077 return residue;
1078
1079 burst_size = chan->mem_burst * chan->mem_width;
1080 modulo = residue % burst_size;
1081 if (modulo)
1082 residue = residue - modulo + burst_size;
1083
1084 return residue;
1085}
1086
1087static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
1088 dma_cookie_t cookie,
1089 struct dma_tx_state *state)
1090{
1091 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1092 struct virt_dma_desc *vdesc;
1093 enum dma_status status;
1094 unsigned long flags;
1095 u32 residue = 0;
1096
1097 status = dma_cookie_status(c, cookie, state);
1098 if (status == DMA_COMPLETE || !state)
1099 return status;
1100
1101 spin_lock_irqsave(&chan->vchan.lock, flags);
1102 vdesc = vchan_find_desc(&chan->vchan, cookie);
1103 if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1104 residue = stm32_dma_desc_residue(chan, chan->desc,
1105 chan->next_sg);
1106 else if (vdesc)
1107 residue = stm32_dma_desc_residue(chan,
1108 to_stm32_dma_desc(vdesc), 0);
1109 dma_set_residue(state, residue);
1110
1111 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1112
1113 return status;
1114}
1115
1116static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
1117{
1118 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1119 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1120 int ret;
1121
1122 chan->config_init = false;
1123 ret = clk_prepare_enable(dmadev->clk);
1124 if (ret < 0) {
1125 dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
1126 return ret;
1127 }
1128
1129 ret = stm32_dma_disable_chan(chan);
1130 if (ret < 0)
1131 clk_disable_unprepare(dmadev->clk);
1132
1133 return ret;
1134}
1135
1136static void stm32_dma_free_chan_resources(struct dma_chan *c)
1137{
1138 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1139 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1140 unsigned long flags;
1141
1142 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1143
1144 if (chan->busy) {
1145 spin_lock_irqsave(&chan->vchan.lock, flags);
1146 stm32_dma_stop(chan);
1147 chan->desc = NULL;
1148 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1149 }
1150
1151 clk_disable_unprepare(dmadev->clk);
1152
1153 vchan_free_chan_resources(to_virt_chan(c));
1154}
1155
1156static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
1157{
1158 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
1159}
1160
1161static void stm32_dma_set_config(struct stm32_dma_chan *chan,
1162 struct stm32_dma_cfg *cfg)
1163{
1164 stm32_dma_clear_reg(&chan->chan_reg);
1165
1166 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
1167 chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
1168
1169 /* Enable Interrupts */
1170 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
1171
1172 chan->threshold = STM32_DMA_THRESHOLD_FTR_GET(cfg->features);
1173}
1174
1175static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
1176 struct of_dma *ofdma)
1177{
1178 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
1179 struct device *dev = dmadev->ddev.dev;
1180 struct stm32_dma_cfg cfg;
1181 struct stm32_dma_chan *chan;
1182 struct dma_chan *c;
1183
1184 if (dma_spec->args_count < 4) {
1185 dev_err(dev, "Bad number of cells\n");
1186 return NULL;
1187 }
1188
1189 cfg.channel_id = dma_spec->args[0];
1190 cfg.request_line = dma_spec->args[1];
1191 cfg.stream_config = dma_spec->args[2];
1192 cfg.features = dma_spec->args[3];
1193
1194 if (cfg.channel_id >= STM32_DMA_MAX_CHANNELS ||
1195 cfg.request_line >= STM32_DMA_MAX_REQUEST_ID) {
1196 dev_err(dev, "Bad channel and/or request id\n");
1197 return NULL;
1198 }
1199
1200 chan = &dmadev->chan[cfg.channel_id];
1201
1202 c = dma_get_slave_channel(&chan->vchan.chan);
1203 if (!c) {
1204 dev_err(dev, "No more channels available\n");
1205 return NULL;
1206 }
1207
1208 stm32_dma_set_config(chan, &cfg);
1209
1210 return c;
1211}
1212
1213static const struct of_device_id stm32_dma_of_match[] = {
1214 { .compatible = "st,stm32-dma", },
1215 { /* sentinel */ },
1216};
1217MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1218
1219static int stm32_dma_probe(struct platform_device *pdev)
1220{
1221 struct stm32_dma_chan *chan;
1222 struct stm32_dma_device *dmadev;
1223 struct dma_device *dd;
1224 const struct of_device_id *match;
1225 struct resource *res;
1226 int i, ret;
1227
1228 match = of_match_device(stm32_dma_of_match, &pdev->dev);
1229 if (!match) {
1230 dev_err(&pdev->dev, "Error: No device match found\n");
1231 return -ENODEV;
1232 }
1233
1234 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1235 if (!dmadev)
1236 return -ENOMEM;
1237
1238 dd = &dmadev->ddev;
1239
1240 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1241 dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1242 if (IS_ERR(dmadev->base))
1243 return PTR_ERR(dmadev->base);
1244
1245 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1246 if (IS_ERR(dmadev->clk)) {
1247 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1248 return PTR_ERR(dmadev->clk);
1249 }
1250
1251 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1252 "st,mem2mem");
1253
1254 dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
1255 if (!IS_ERR(dmadev->rst)) {
1256 reset_control_assert(dmadev->rst);
1257 udelay(2);
1258 reset_control_deassert(dmadev->rst);
1259 }
1260
1261 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1262 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1263 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1264 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1265 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1266 dd->device_tx_status = stm32_dma_tx_status;
1267 dd->device_issue_pending = stm32_dma_issue_pending;
1268 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1269 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1270 dd->device_config = stm32_dma_slave_config;
1271 dd->device_terminate_all = stm32_dma_terminate_all;
1272 dd->device_synchronize = stm32_dma_synchronize;
1273 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1274 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1275 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1276 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1277 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1278 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1279 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1280 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1281 dd->max_burst = STM32_DMA_MAX_BURST;
1282 dd->dev = &pdev->dev;
1283 INIT_LIST_HEAD(&dd->channels);
1284
1285 if (dmadev->mem2mem) {
1286 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1287 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1288 dd->directions |= BIT(DMA_MEM_TO_MEM);
1289 }
1290
1291 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1292 chan = &dmadev->chan[i];
1293 chan->id = i;
1294 chan->vchan.desc_free = stm32_dma_desc_free;
1295 vchan_init(&chan->vchan, dd);
1296 }
1297
1298 ret = dma_async_device_register(dd);
1299 if (ret)
1300 return ret;
1301
1302 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1303 chan = &dmadev->chan[i];
1304 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1305 if (!res) {
1306 ret = -EINVAL;
1307 dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1308 goto err_unregister;
1309 }
1310 chan->irq = res->start;
1311 ret = devm_request_irq(&pdev->dev, chan->irq,
1312 stm32_dma_chan_irq, 0,
1313 dev_name(chan2dev(chan)), chan);
1314 if (ret) {
1315 dev_err(&pdev->dev,
1316 "request_irq failed with err %d channel %d\n",
1317 ret, i);
1318 goto err_unregister;
1319 }
1320 }
1321
1322 ret = of_dma_controller_register(pdev->dev.of_node,
1323 stm32_dma_of_xlate, dmadev);
1324 if (ret < 0) {
1325 dev_err(&pdev->dev,
1326 "STM32 DMA DMA OF registration failed %d\n", ret);
1327 goto err_unregister;
1328 }
1329
1330 platform_set_drvdata(pdev, dmadev);
1331
1332 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1333
1334 return 0;
1335
1336err_unregister:
1337 dma_async_device_unregister(dd);
1338
1339 return ret;
1340}
1341
1342static struct platform_driver stm32_dma_driver = {
1343 .driver = {
1344 .name = "stm32-dma",
1345 .of_match_table = stm32_dma_of_match,
1346 },
1347};
1348
1349static int __init stm32_dma_init(void)
1350{
1351 return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
1352}
1353subsys_initcall(stm32_dma_init);