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ntb: remove unneeded DRIVER_LICENSE #defines
[linux/fpc-iii.git] / drivers / dma / stm32-dma.c
blob786fc8fcc38ed6a2f2442a18a36bc4ab6ad4c273
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 *
9 * License terms: GNU General Public License (GPL), version 2
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/reset.h>
26 #include <linux/sched.h>
27 #include <linux/slab.h>
28
29 #include "virt-dma.h"
30
31 #define STM32_DMA_LISR 0x0000 /* DMA Low Int Status Reg */
32 #define STM32_DMA_HISR 0x0004 /* DMA High Int Status Reg */
33 #define STM32_DMA_LIFCR 0x0008 /* DMA Low Int Flag Clear Reg */
34 #define STM32_DMA_HIFCR 0x000c /* DMA High Int Flag Clear Reg */
35 #define STM32_DMA_TCI BIT(5) /* Transfer Complete Interrupt */
36 #define STM32_DMA_TEI BIT(3) /* Transfer Error Interrupt */
37 #define STM32_DMA_DMEI BIT(2) /* Direct Mode Error Interrupt */
38 #define STM32_DMA_FEI BIT(0) /* FIFO Error Interrupt */
39
40 /* DMA Stream x Configuration Register */
41 #define STM32_DMA_SCR(x) (0x0010 + 0x18 * (x)) /* x = 0..7 */
42 #define STM32_DMA_SCR_REQ(n) ((n & 0x7) << 25)
43 #define STM32_DMA_SCR_MBURST_MASK GENMASK(24, 23)
44 #define STM32_DMA_SCR_MBURST(n) ((n & 0x3) << 23)
45 #define STM32_DMA_SCR_PBURST_MASK GENMASK(22, 21)
46 #define STM32_DMA_SCR_PBURST(n) ((n & 0x3) << 21)
47 #define STM32_DMA_SCR_PL_MASK GENMASK(17, 16)
48 #define STM32_DMA_SCR_PL(n) ((n & 0x3) << 16)
49 #define STM32_DMA_SCR_MSIZE_MASK GENMASK(14, 13)
50 #define STM32_DMA_SCR_MSIZE(n) ((n & 0x3) << 13)
51 #define STM32_DMA_SCR_PSIZE_MASK GENMASK(12, 11)
52 #define STM32_DMA_SCR_PSIZE(n) ((n & 0x3) << 11)
53 #define STM32_DMA_SCR_PSIZE_GET(n) ((n & STM32_DMA_SCR_PSIZE_MASK) >> 11)
54 #define STM32_DMA_SCR_DIR_MASK GENMASK(7, 6)
55 #define STM32_DMA_SCR_DIR(n) ((n & 0x3) << 6)
56 #define STM32_DMA_SCR_CT BIT(19) /* Target in double buffer */
57 #define STM32_DMA_SCR_DBM BIT(18) /* Double Buffer Mode */
58 #define STM32_DMA_SCR_PINCOS BIT(15) /* Peripheral inc offset size */
59 #define STM32_DMA_SCR_MINC BIT(10) /* Memory increment mode */
60 #define STM32_DMA_SCR_PINC BIT(9) /* Peripheral increment mode */
61 #define STM32_DMA_SCR_CIRC BIT(8) /* Circular mode */
62 #define STM32_DMA_SCR_PFCTRL BIT(5) /* Peripheral Flow Controller */
63 #define STM32_DMA_SCR_TCIE BIT(4) /* Transfer Cplete Int Enable*/
64 #define STM32_DMA_SCR_TEIE BIT(2) /* Transfer Error Int Enable */
65 #define STM32_DMA_SCR_DMEIE BIT(1) /* Direct Mode Err Int Enable */
66 #define STM32_DMA_SCR_EN BIT(0) /* Stream Enable */
67 #define STM32_DMA_SCR_CFG_MASK (STM32_DMA_SCR_PINC \
68 | STM32_DMA_SCR_MINC \
69 | STM32_DMA_SCR_PINCOS \
70 | STM32_DMA_SCR_PL_MASK)
71 #define STM32_DMA_SCR_IRQ_MASK (STM32_DMA_SCR_TCIE \
72 | STM32_DMA_SCR_TEIE \
73 | STM32_DMA_SCR_DMEIE)
74
75 /* DMA Stream x number of data register */
76 #define STM32_DMA_SNDTR(x) (0x0014 + 0x18 * (x))
77
78 /* DMA stream peripheral address register */
79 #define STM32_DMA_SPAR(x) (0x0018 + 0x18 * (x))
80
81 /* DMA stream x memory 0 address register */
82 #define STM32_DMA_SM0AR(x) (0x001c + 0x18 * (x))
83
84 /* DMA stream x memory 1 address register */
85 #define STM32_DMA_SM1AR(x) (0x0020 + 0x18 * (x))
86
87 /* DMA stream x FIFO control register */
88 #define STM32_DMA_SFCR(x) (0x0024 + 0x18 * (x))
89 #define STM32_DMA_SFCR_FTH_MASK GENMASK(1, 0)
90 #define STM32_DMA_SFCR_FTH(n) (n & STM32_DMA_SFCR_FTH_MASK)
91 #define STM32_DMA_SFCR_FEIE BIT(7) /* FIFO error interrupt enable */
92 #define STM32_DMA_SFCR_DMDIS BIT(2) /* Direct mode disable */
93 #define STM32_DMA_SFCR_MASK (STM32_DMA_SFCR_FEIE \
94 | STM32_DMA_SFCR_DMDIS)
95
96 /* DMA direction */
97 #define STM32_DMA_DEV_TO_MEM 0x00
98 #define STM32_DMA_MEM_TO_DEV 0x01
99 #define STM32_DMA_MEM_TO_MEM 0x02
100
101 /* DMA priority level */
102 #define STM32_DMA_PRIORITY_LOW 0x00
103 #define STM32_DMA_PRIORITY_MEDIUM 0x01
104 #define STM32_DMA_PRIORITY_HIGH 0x02
105 #define STM32_DMA_PRIORITY_VERY_HIGH 0x03
106
107 /* DMA FIFO threshold selection */
108 #define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL 0x00
109 #define STM32_DMA_FIFO_THRESHOLD_HALFFULL 0x01
110 #define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL 0x02
111 #define STM32_DMA_FIFO_THRESHOLD_FULL 0x03
112
113 #define STM32_DMA_MAX_DATA_ITEMS 0xffff
114 #define STM32_DMA_MAX_CHANNELS 0x08
115 #define STM32_DMA_MAX_REQUEST_ID 0x08
116 #define STM32_DMA_MAX_DATA_PARAM 0x03
117 #define STM32_DMA_MAX_BURST 16
118
119 enum stm32_dma_width {
120 STM32_DMA_BYTE,
121 STM32_DMA_HALF_WORD,
122 STM32_DMA_WORD,
123 };
124
125 enum stm32_dma_burst_size {
126 STM32_DMA_BURST_SINGLE,
127 STM32_DMA_BURST_INCR4,
128 STM32_DMA_BURST_INCR8,
129 STM32_DMA_BURST_INCR16,
130 };
131
132 struct stm32_dma_cfg {
133 u32 channel_id;
134 u32 request_line;
135 u32 stream_config;
136 u32 threshold;
137 };
138
139 struct stm32_dma_chan_reg {
140 u32 dma_lisr;
141 u32 dma_hisr;
142 u32 dma_lifcr;
143 u32 dma_hifcr;
144 u32 dma_scr;
145 u32 dma_sndtr;
146 u32 dma_spar;
147 u32 dma_sm0ar;
148 u32 dma_sm1ar;
149 u32 dma_sfcr;
150 };
151
152 struct stm32_dma_sg_req {
153 u32 len;
154 struct stm32_dma_chan_reg chan_reg;
155 };
156
157 struct stm32_dma_desc {
158 struct virt_dma_desc vdesc;
159 bool cyclic;
160 u32 num_sgs;
161 struct stm32_dma_sg_req sg_req[];
162 };
163
164 struct stm32_dma_chan {
165 struct virt_dma_chan vchan;
166 bool config_init;
167 bool busy;
168 u32 id;
169 u32 irq;
170 struct stm32_dma_desc *desc;
171 u32 next_sg;
172 struct dma_slave_config dma_sconfig;
173 struct stm32_dma_chan_reg chan_reg;
174 };
175
176 struct stm32_dma_device {
177 struct dma_device ddev;
178 void __iomem *base;
179 struct clk *clk;
180 struct reset_control *rst;
181 bool mem2mem;
182 struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
183 };
184
185 static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
186 {
187 return container_of(chan->vchan.chan.device, struct stm32_dma_device,
188 ddev);
189 }
190
191 static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
192 {
193 return container_of(c, struct stm32_dma_chan, vchan.chan);
194 }
195
196 static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
197 {
198 return container_of(vdesc, struct stm32_dma_desc, vdesc);
199 }
200
201 static struct device *chan2dev(struct stm32_dma_chan *chan)
202 {
203 return &chan->vchan.chan.dev->device;
204 }
205
206 static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
207 {
208 return readl_relaxed(dmadev->base + reg);
209 }
210
211 static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
212 {
213 writel_relaxed(val, dmadev->base + reg);
214 }
215
216 static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs)
217 {
218 return kzalloc(sizeof(struct stm32_dma_desc) +
219 sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT);
220 }
221
222 static int stm32_dma_get_width(struct stm32_dma_chan *chan,
223 enum dma_slave_buswidth width)
224 {
225 switch (width) {
226 case DMA_SLAVE_BUSWIDTH_1_BYTE:
227 return STM32_DMA_BYTE;
228 case DMA_SLAVE_BUSWIDTH_2_BYTES:
229 return STM32_DMA_HALF_WORD;
230 case DMA_SLAVE_BUSWIDTH_4_BYTES:
231 return STM32_DMA_WORD;
232 default:
233 dev_err(chan2dev(chan), "Dma bus width not supported\n");
234 return -EINVAL;
235 }
236 }
237
238 static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
239 {
240 switch (maxburst) {
241 case 0:
242 case 1:
243 return STM32_DMA_BURST_SINGLE;
244 case 4:
245 return STM32_DMA_BURST_INCR4;
246 case 8:
247 return STM32_DMA_BURST_INCR8;
248 case 16:
249 return STM32_DMA_BURST_INCR16;
250 default:
251 dev_err(chan2dev(chan), "Dma burst size not supported\n");
252 return -EINVAL;
253 }
254 }
255
256 static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
257 u32 src_maxburst, u32 dst_maxburst)
258 {
259 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
260 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
261
262 if ((!src_maxburst) && (!dst_maxburst)) {
263 /* Using direct mode */
264 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
265 } else {
266 /* Using FIFO mode */
267 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
268 }
269 }
270
271 static int stm32_dma_slave_config(struct dma_chan *c,
272 struct dma_slave_config *config)
273 {
274 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
275
276 memcpy(&chan->dma_sconfig, config, sizeof(*config));
277
278 chan->config_init = true;
279
280 return 0;
281 }
282
283 static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
284 {
285 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
286 u32 flags, dma_isr;
287
288 /*
289 * Read "flags" from DMA_xISR register corresponding to the selected
290 * DMA channel at the correct bit offset inside that register.
291 *
292 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
293 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
294 */
295
296 if (chan->id & 4)
297 dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR);
298 else
299 dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR);
300
301 flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
302
303 return flags;
304 }
305
306 static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
307 {
308 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
309 u32 dma_ifcr;
310
311 /*
312 * Write "flags" to the DMA_xIFCR register corresponding to the selected
313 * DMA channel at the correct bit offset inside that register.
314 *
315 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
316 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
317 */
318 dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
319
320 if (chan->id & 4)
321 stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr);
322 else
323 stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr);
324 }
325
326 static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
327 {
328 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
329 unsigned long timeout = jiffies + msecs_to_jiffies(5000);
330 u32 dma_scr, id;
331
332 id = chan->id;
333 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
334
335 if (dma_scr & STM32_DMA_SCR_EN) {
336 dma_scr &= ~STM32_DMA_SCR_EN;
337 stm32_dma_write(dmadev, STM32_DMA_SCR(id), dma_scr);
338
339 do {
340 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
341 dma_scr &= STM32_DMA_SCR_EN;
342 if (!dma_scr)
343 break;
344
345 if (time_after_eq(jiffies, timeout)) {
346 dev_err(chan2dev(chan), "%s: timeout!\n",
347 __func__);
348 return -EBUSY;
349 }
350 cond_resched();
351 } while (1);
352 }
353
354 return 0;
355 }
356
357 static void stm32_dma_stop(struct stm32_dma_chan *chan)
358 {
359 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
360 u32 dma_scr, dma_sfcr, status;
361 int ret;
362
363 /* Disable interrupts */
364 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
365 dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
366 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
367 dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
368 dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
369 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
370
371 /* Disable DMA */
372 ret = stm32_dma_disable_chan(chan);
373 if (ret < 0)
374 return;
375
376 /* Clear interrupt status if it is there */
377 status = stm32_dma_irq_status(chan);
378 if (status) {
379 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
380 __func__, status);
381 stm32_dma_irq_clear(chan, status);
382 }
383
384 chan->busy = false;
385 }
386
387 static int stm32_dma_terminate_all(struct dma_chan *c)
388 {
389 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
390 unsigned long flags;
391 LIST_HEAD(head);
392
393 spin_lock_irqsave(&chan->vchan.lock, flags);
394
395 if (chan->busy) {
396 stm32_dma_stop(chan);
397 chan->desc = NULL;
398 }
399
400 vchan_get_all_descriptors(&chan->vchan, &head);
401 spin_unlock_irqrestore(&chan->vchan.lock, flags);
402 vchan_dma_desc_free_list(&chan->vchan, &head);
403
404 return 0;
405 }
406
407 static void stm32_dma_synchronize(struct dma_chan *c)
408 {
409 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
410
411 vchan_synchronize(&chan->vchan);
412 }
413
414 static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
415 {
416 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
417 u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
418 u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
419 u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
420 u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
421 u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
422 u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
423
424 dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr);
425 dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr);
426 dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar);
427 dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
428 dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
429 dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
430 }
431
432 static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
433 {
434 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
435 struct virt_dma_desc *vdesc;
436 struct stm32_dma_sg_req *sg_req;
437 struct stm32_dma_chan_reg *reg;
438 u32 status;
439 int ret;
440
441 ret = stm32_dma_disable_chan(chan);
442 if (ret < 0)
443 return;
444
445 if (!chan->desc) {
446 vdesc = vchan_next_desc(&chan->vchan);
447 if (!vdesc)
448 return;
449
450 chan->desc = to_stm32_dma_desc(vdesc);
451 chan->next_sg = 0;
452 }
453
454 if (chan->next_sg == chan->desc->num_sgs)
455 chan->next_sg = 0;
456
457 sg_req = &chan->desc->sg_req[chan->next_sg];
458 reg = &sg_req->chan_reg;
459
460 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
461 stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
462 stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
463 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
464 stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
465 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
466
467 chan->next_sg++;
468
469 /* Clear interrupt status if it is there */
470 status = stm32_dma_irq_status(chan);
471 if (status)
472 stm32_dma_irq_clear(chan, status);
473
474 stm32_dma_dump_reg(chan);
475
476 /* Start DMA */
477 reg->dma_scr |= STM32_DMA_SCR_EN;
478 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
479
480 chan->busy = true;
481
482 dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);
483 }
484
485 static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
486 {
487 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
488 struct stm32_dma_sg_req *sg_req;
489 u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
490
491 id = chan->id;
492 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
493
494 if (dma_scr & STM32_DMA_SCR_DBM) {
495 if (chan->next_sg == chan->desc->num_sgs)
496 chan->next_sg = 0;
497
498 sg_req = &chan->desc->sg_req[chan->next_sg];
499
500 if (dma_scr & STM32_DMA_SCR_CT) {
501 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
502 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
503 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
504 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
505 } else {
506 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
507 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
508 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
509 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
510 }
511 }
512 }
513
514 static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
515 {
516 if (chan->desc) {
517 if (chan->desc->cyclic) {
518 vchan_cyclic_callback(&chan->desc->vdesc);
519 chan->next_sg++;
520 stm32_dma_configure_next_sg(chan);
521 } else {
522 chan->busy = false;
523 if (chan->next_sg == chan->desc->num_sgs) {
524 list_del(&chan->desc->vdesc.node);
525 vchan_cookie_complete(&chan->desc->vdesc);
526 chan->desc = NULL;
527 }
528 stm32_dma_start_transfer(chan);
529 }
530 }
531 }
532
533 static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
534 {
535 struct stm32_dma_chan *chan = devid;
536 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
537 u32 status, scr;
538
539 spin_lock(&chan->vchan.lock);
540
541 status = stm32_dma_irq_status(chan);
542 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
543
544 if ((status & STM32_DMA_TCI) && (scr & STM32_DMA_SCR_TCIE)) {
545 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
546 stm32_dma_handle_chan_done(chan);
547
548 } else {
549 stm32_dma_irq_clear(chan, status);
550 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
551 }
552
553 spin_unlock(&chan->vchan.lock);
554
555 return IRQ_HANDLED;
556 }
557
558 static void stm32_dma_issue_pending(struct dma_chan *c)
559 {
560 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
561 unsigned long flags;
562
563 spin_lock_irqsave(&chan->vchan.lock, flags);
564 if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
565 dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
566 stm32_dma_start_transfer(chan);
567 if (chan->desc->cyclic)
568 stm32_dma_configure_next_sg(chan);
569 }
570 spin_unlock_irqrestore(&chan->vchan.lock, flags);
571 }
572
573 static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
574 enum dma_transfer_direction direction,
575 enum dma_slave_buswidth *buswidth)
576 {
577 enum dma_slave_buswidth src_addr_width, dst_addr_width;
578 int src_bus_width, dst_bus_width;
579 int src_burst_size, dst_burst_size;
580 u32 src_maxburst, dst_maxburst;
581 u32 dma_scr = 0;
582
583 src_addr_width = chan->dma_sconfig.src_addr_width;
584 dst_addr_width = chan->dma_sconfig.dst_addr_width;
585 src_maxburst = chan->dma_sconfig.src_maxburst;
586 dst_maxburst = chan->dma_sconfig.dst_maxburst;
587
588 switch (direction) {
589 case DMA_MEM_TO_DEV:
590 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
591 if (dst_bus_width < 0)
592 return dst_bus_width;
593
594 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
595 if (dst_burst_size < 0)
596 return dst_burst_size;
597
598 if (!src_addr_width)
599 src_addr_width = dst_addr_width;
600
601 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
602 if (src_bus_width < 0)
603 return src_bus_width;
604
605 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
606 if (src_burst_size < 0)
607 return src_burst_size;
608
609 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
610 STM32_DMA_SCR_PSIZE(dst_bus_width) |
611 STM32_DMA_SCR_MSIZE(src_bus_width) |
612 STM32_DMA_SCR_PBURST(dst_burst_size) |
613 STM32_DMA_SCR_MBURST(src_burst_size);
614
615 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
616 *buswidth = dst_addr_width;
617 break;
618
619 case DMA_DEV_TO_MEM:
620 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
621 if (src_bus_width < 0)
622 return src_bus_width;
623
624 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
625 if (src_burst_size < 0)
626 return src_burst_size;
627
628 if (!dst_addr_width)
629 dst_addr_width = src_addr_width;
630
631 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
632 if (dst_bus_width < 0)
633 return dst_bus_width;
634
635 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
636 if (dst_burst_size < 0)
637 return dst_burst_size;
638
639 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
640 STM32_DMA_SCR_PSIZE(src_bus_width) |
641 STM32_DMA_SCR_MSIZE(dst_bus_width) |
642 STM32_DMA_SCR_PBURST(src_burst_size) |
643 STM32_DMA_SCR_MBURST(dst_burst_size);
644
645 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
646 *buswidth = chan->dma_sconfig.src_addr_width;
647 break;
648
649 default:
650 dev_err(chan2dev(chan), "Dma direction is not supported\n");
651 return -EINVAL;
652 }
653
654 stm32_dma_set_fifo_config(chan, src_maxburst, dst_maxburst);
655
656 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
657 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
658 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
659 chan->chan_reg.dma_scr |= dma_scr;
660
661 return 0;
662 }
663
664 static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
665 {
666 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
667 }
668
669 static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
670 struct dma_chan *c, struct scatterlist *sgl,
671 u32 sg_len, enum dma_transfer_direction direction,
672 unsigned long flags, void *context)
673 {
674 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
675 struct stm32_dma_desc *desc;
676 struct scatterlist *sg;
677 enum dma_slave_buswidth buswidth;
678 u32 nb_data_items;
679 int i, ret;
680
681 if (!chan->config_init) {
682 dev_err(chan2dev(chan), "dma channel is not configured\n");
683 return NULL;
684 }
685
686 if (sg_len < 1) {
687 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
688 return NULL;
689 }
690
691 desc = stm32_dma_alloc_desc(sg_len);
692 if (!desc)
693 return NULL;
694
695 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
696 if (ret < 0)
697 goto err;
698
699 /* Set peripheral flow controller */
700 if (chan->dma_sconfig.device_fc)
701 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
702 else
703 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
704
705 for_each_sg(sgl, sg, sg_len, i) {
706 desc->sg_req[i].len = sg_dma_len(sg);
707
708 nb_data_items = desc->sg_req[i].len / buswidth;
709 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
710 dev_err(chan2dev(chan), "nb items not supported\n");
711 goto err;
712 }
713
714 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
715 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
716 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
717 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
718 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
719 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
720 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
721 }
722
723 desc->num_sgs = sg_len;
724 desc->cyclic = false;
725
726 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
727
728 err:
729 kfree(desc);
730 return NULL;
731 }
732
733 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
734 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
735 size_t period_len, enum dma_transfer_direction direction,
736 unsigned long flags)
737 {
738 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
739 struct stm32_dma_desc *desc;
740 enum dma_slave_buswidth buswidth;
741 u32 num_periods, nb_data_items;
742 int i, ret;
743
744 if (!buf_len || !period_len) {
745 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
746 return NULL;
747 }
748
749 if (!chan->config_init) {
750 dev_err(chan2dev(chan), "dma channel is not configured\n");
751 return NULL;
752 }
753
754 if (buf_len % period_len) {
755 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
756 return NULL;
757 }
758
759 /*
760 * We allow to take more number of requests till DMA is
761 * not started. The driver will loop over all requests.
762 * Once DMA is started then new requests can be queued only after
763 * terminating the DMA.
764 */
765 if (chan->busy) {
766 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
767 return NULL;
768 }
769
770 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
771 if (ret < 0)
772 return NULL;
773
774 nb_data_items = period_len / buswidth;
775 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
776 dev_err(chan2dev(chan), "number of items not supported\n");
777 return NULL;
778 }
779
780 /* Enable Circular mode or double buffer mode */
781 if (buf_len == period_len)
782 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
783 else
784 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
785
786 /* Clear periph ctrl if client set it */
787 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
788
789 num_periods = buf_len / period_len;
790
791 desc = stm32_dma_alloc_desc(num_periods);
792 if (!desc)
793 return NULL;
794
795 for (i = 0; i < num_periods; i++) {
796 desc->sg_req[i].len = period_len;
797
798 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
799 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
800 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
801 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
802 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
803 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
804 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
805 buf_addr += period_len;
806 }
807
808 desc->num_sgs = num_periods;
809 desc->cyclic = true;
810
811 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
812 }
813
814 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
815 struct dma_chan *c, dma_addr_t dest,
816 dma_addr_t src, size_t len, unsigned long flags)
817 {
818 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
819 u32 num_sgs;
820 struct stm32_dma_desc *desc;
821 size_t xfer_count, offset;
822 int i;
823
824 num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS);
825 desc = stm32_dma_alloc_desc(num_sgs);
826 if (!desc)
827 return NULL;
828
829 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
830 xfer_count = min_t(size_t, len - offset,
831 STM32_DMA_MAX_DATA_ITEMS);
832
833 desc->sg_req[i].len = xfer_count;
834
835 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
836 desc->sg_req[i].chan_reg.dma_scr =
837 STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
838 STM32_DMA_SCR_MINC |
839 STM32_DMA_SCR_PINC |
840 STM32_DMA_SCR_TCIE |
841 STM32_DMA_SCR_TEIE;
842 desc->sg_req[i].chan_reg.dma_sfcr = STM32_DMA_SFCR_DMDIS |
843 STM32_DMA_SFCR_FTH(STM32_DMA_FIFO_THRESHOLD_FULL) |
844 STM32_DMA_SFCR_FEIE;
845 desc->sg_req[i].chan_reg.dma_spar = src + offset;
846 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
847 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
848 }
849
850 desc->num_sgs = num_sgs;
851 desc->cyclic = false;
852
853 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
854 }
855
856 static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
857 {
858 u32 dma_scr, width, ndtr;
859 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
860
861 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
862 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
863 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
864
865 return ndtr << width;
866 }
867
868 static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
869 struct stm32_dma_desc *desc,
870 u32 next_sg)
871 {
872 u32 residue = 0;
873 int i;
874
875 /*
876 * In cyclic mode, for the last period, residue = remaining bytes from
877 * NDTR
878 */
879 if (chan->desc->cyclic && next_sg == 0)
880 return stm32_dma_get_remaining_bytes(chan);
881
882 /*
883 * For all other periods in cyclic mode, and in sg mode,
884 * residue = remaining bytes from NDTR + remaining periods/sg to be
885 * transferred
886 */
887 for (i = next_sg; i < desc->num_sgs; i++)
888 residue += desc->sg_req[i].len;
889 residue += stm32_dma_get_remaining_bytes(chan);
890
891 return residue;
892 }
893
894 static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
895 dma_cookie_t cookie,
896 struct dma_tx_state *state)
897 {
898 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
899 struct virt_dma_desc *vdesc;
900 enum dma_status status;
901 unsigned long flags;
902 u32 residue = 0;
903
904 status = dma_cookie_status(c, cookie, state);
905 if ((status == DMA_COMPLETE) || (!state))
906 return status;
907
908 spin_lock_irqsave(&chan->vchan.lock, flags);
909 vdesc = vchan_find_desc(&chan->vchan, cookie);
910 if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
911 residue = stm32_dma_desc_residue(chan, chan->desc,
912 chan->next_sg);
913 else if (vdesc)
914 residue = stm32_dma_desc_residue(chan,
915 to_stm32_dma_desc(vdesc), 0);
916 dma_set_residue(state, residue);
917
918 spin_unlock_irqrestore(&chan->vchan.lock, flags);
919
920 return status;
921 }
922
923 static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
924 {
925 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
926 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
927 int ret;
928
929 chan->config_init = false;
930 ret = clk_prepare_enable(dmadev->clk);
931 if (ret < 0) {
932 dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
933 return ret;
934 }
935
936 ret = stm32_dma_disable_chan(chan);
937 if (ret < 0)
938 clk_disable_unprepare(dmadev->clk);
939
940 return ret;
941 }
942
943 static void stm32_dma_free_chan_resources(struct dma_chan *c)
944 {
945 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
946 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
947 unsigned long flags;
948
949 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
950
951 if (chan->busy) {
952 spin_lock_irqsave(&chan->vchan.lock, flags);
953 stm32_dma_stop(chan);
954 chan->desc = NULL;
955 spin_unlock_irqrestore(&chan->vchan.lock, flags);
956 }
957
958 clk_disable_unprepare(dmadev->clk);
959
960 vchan_free_chan_resources(to_virt_chan(c));
961 }
962
963 static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
964 {
965 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
966 }
967
968 static void stm32_dma_set_config(struct stm32_dma_chan *chan,
969 struct stm32_dma_cfg *cfg)
970 {
971 stm32_dma_clear_reg(&chan->chan_reg);
972
973 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
974 chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
975
976 /* Enable Interrupts */
977 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
978
979 chan->chan_reg.dma_sfcr = cfg->threshold & STM32_DMA_SFCR_FTH_MASK;
980 }
981
982 static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
983 struct of_dma *ofdma)
984 {
985 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
986 struct device *dev = dmadev->ddev.dev;
987 struct stm32_dma_cfg cfg;
988 struct stm32_dma_chan *chan;
989 struct dma_chan *c;
990
991 if (dma_spec->args_count < 4) {
992 dev_err(dev, "Bad number of cells\n");
993 return NULL;
994 }
995
996 cfg.channel_id = dma_spec->args[0];
997 cfg.request_line = dma_spec->args[1];
998 cfg.stream_config = dma_spec->args[2];
999 cfg.threshold = dma_spec->args[3];
1000
1001 if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) ||
1002 (cfg.request_line >= STM32_DMA_MAX_REQUEST_ID)) {
1003 dev_err(dev, "Bad channel and/or request id\n");
1004 return NULL;
1005 }
1006
1007 chan = &dmadev->chan[cfg.channel_id];
1008
1009 c = dma_get_slave_channel(&chan->vchan.chan);
1010 if (!c) {
1011 dev_err(dev, "No more channels available\n");
1012 return NULL;
1013 }
1014
1015 stm32_dma_set_config(chan, &cfg);
1016
1017 return c;
1018 }
1019
1020 static const struct of_device_id stm32_dma_of_match[] = {
1021 { .compatible = "st,stm32-dma", },
1022 { /* sentinel */ },
1023 };
1024 MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1025
1026 static int stm32_dma_probe(struct platform_device *pdev)
1027 {
1028 struct stm32_dma_chan *chan;
1029 struct stm32_dma_device *dmadev;
1030 struct dma_device *dd;
1031 const struct of_device_id *match;
1032 struct resource *res;
1033 int i, ret;
1034
1035 match = of_match_device(stm32_dma_of_match, &pdev->dev);
1036 if (!match) {
1037 dev_err(&pdev->dev, "Error: No device match found\n");
1038 return -ENODEV;
1039 }
1040
1041 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1042 if (!dmadev)
1043 return -ENOMEM;
1044
1045 dd = &dmadev->ddev;
1046
1047 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1048 dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1049 if (IS_ERR(dmadev->base))
1050 return PTR_ERR(dmadev->base);
1051
1052 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1053 if (IS_ERR(dmadev->clk)) {
1054 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1055 return PTR_ERR(dmadev->clk);
1056 }
1057
1058 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1059 "st,mem2mem");
1060
1061 dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
1062 if (!IS_ERR(dmadev->rst)) {
1063 reset_control_assert(dmadev->rst);
1064 udelay(2);
1065 reset_control_deassert(dmadev->rst);
1066 }
1067
1068 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1069 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1070 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1071 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1072 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1073 dd->device_tx_status = stm32_dma_tx_status;
1074 dd->device_issue_pending = stm32_dma_issue_pending;
1075 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1076 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1077 dd->device_config = stm32_dma_slave_config;
1078 dd->device_terminate_all = stm32_dma_terminate_all;
1079 dd->device_synchronize = stm32_dma_synchronize;
1080 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1081 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1082 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1083 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1084 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1085 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1086 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1087 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1088 dd->max_burst = STM32_DMA_MAX_BURST;
1089 dd->dev = &pdev->dev;
1090 INIT_LIST_HEAD(&dd->channels);
1091
1092 if (dmadev->mem2mem) {
1093 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1094 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1095 dd->directions |= BIT(DMA_MEM_TO_MEM);
1096 }
1097
1098 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1099 chan = &dmadev->chan[i];
1100 chan->id = i;
1101 chan->vchan.desc_free = stm32_dma_desc_free;
1102 vchan_init(&chan->vchan, dd);
1103 }
1104
1105 ret = dma_async_device_register(dd);
1106 if (ret)
1107 return ret;
1108
1109 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1110 chan = &dmadev->chan[i];
1111 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1112 if (!res) {
1113 ret = -EINVAL;
1114 dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1115 goto err_unregister;
1116 }
1117 chan->irq = res->start;
1118 ret = devm_request_irq(&pdev->dev, chan->irq,
1119 stm32_dma_chan_irq, 0,
1120 dev_name(chan2dev(chan)), chan);
1121 if (ret) {
1122 dev_err(&pdev->dev,
1123 "request_irq failed with err %d channel %d\n",
1124 ret, i);
1125 goto err_unregister;
1126 }
1127 }
1128
1129 ret = of_dma_controller_register(pdev->dev.of_node,
1130 stm32_dma_of_xlate, dmadev);
1131 if (ret < 0) {
1132 dev_err(&pdev->dev,
1133 "STM32 DMA DMA OF registration failed %d\n", ret);
1134 goto err_unregister;
1135 }
1136
1137 platform_set_drvdata(pdev, dmadev);
1138
1139 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1140
1141 return 0;
1142
1143 err_unregister:
1144 dma_async_device_unregister(dd);
1145
1146 return ret;
1147 }
1148
1149 static struct platform_driver stm32_dma_driver = {
1150 .driver = {
1151 .name = "stm32-dma",
1152 .of_match_table = stm32_dma_of_match,
1153 },
1154 };
1155
1156 static int __init stm32_dma_init(void)
1157 {
1158 return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
1159 }
1160 subsys_initcall(stm32_dma_init);
Linux with added FPC-III support