?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / drivers / dma / stm32-dma.c
blob047476a1383dd984edd2afeb2bf2e1bfd5867074
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
118 enum stm32_dma_width {
119 STM32_DMA_BYTE,
120 STM32_DMA_HALF_WORD,
121 STM32_DMA_WORD,
122 };
123
124 enum stm32_dma_burst_size {
125 STM32_DMA_BURST_SINGLE,
126 STM32_DMA_BURST_INCR4,
127 STM32_DMA_BURST_INCR8,
128 STM32_DMA_BURST_INCR16,
129 };
130
131 struct stm32_dma_cfg {
132 u32 channel_id;
133 u32 request_line;
134 u32 stream_config;
135 u32 threshold;
136 };
137
138 struct stm32_dma_chan_reg {
139 u32 dma_lisr;
140 u32 dma_hisr;
141 u32 dma_lifcr;
142 u32 dma_hifcr;
143 u32 dma_scr;
144 u32 dma_sndtr;
145 u32 dma_spar;
146 u32 dma_sm0ar;
147 u32 dma_sm1ar;
148 u32 dma_sfcr;
149 };
150
151 struct stm32_dma_sg_req {
152 u32 len;
153 struct stm32_dma_chan_reg chan_reg;
154 };
155
156 struct stm32_dma_desc {
157 struct virt_dma_desc vdesc;
158 bool cyclic;
159 u32 num_sgs;
160 struct stm32_dma_sg_req sg_req[];
161 };
162
163 struct stm32_dma_chan {
164 struct virt_dma_chan vchan;
165 bool config_init;
166 bool busy;
167 u32 id;
168 u32 irq;
169 struct stm32_dma_desc *desc;
170 u32 next_sg;
171 struct dma_slave_config dma_sconfig;
172 struct stm32_dma_chan_reg chan_reg;
173 };
174
175 struct stm32_dma_device {
176 struct dma_device ddev;
177 void __iomem *base;
178 struct clk *clk;
179 struct reset_control *rst;
180 bool mem2mem;
181 struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
182 };
183
184 static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
185 {
186 return container_of(chan->vchan.chan.device, struct stm32_dma_device,
187 ddev);
188 }
189
190 static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
191 {
192 return container_of(c, struct stm32_dma_chan, vchan.chan);
193 }
194
195 static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
196 {
197 return container_of(vdesc, struct stm32_dma_desc, vdesc);
198 }
199
200 static struct device *chan2dev(struct stm32_dma_chan *chan)
201 {
202 return &chan->vchan.chan.dev->device;
203 }
204
205 static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
206 {
207 return readl_relaxed(dmadev->base + reg);
208 }
209
210 static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
211 {
212 writel_relaxed(val, dmadev->base + reg);
213 }
214
215 static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs)
216 {
217 return kzalloc(sizeof(struct stm32_dma_desc) +
218 sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT);
219 }
220
221 static int stm32_dma_get_width(struct stm32_dma_chan *chan,
222 enum dma_slave_buswidth width)
223 {
224 switch (width) {
225 case DMA_SLAVE_BUSWIDTH_1_BYTE:
226 return STM32_DMA_BYTE;
227 case DMA_SLAVE_BUSWIDTH_2_BYTES:
228 return STM32_DMA_HALF_WORD;
229 case DMA_SLAVE_BUSWIDTH_4_BYTES:
230 return STM32_DMA_WORD;
231 default:
232 dev_err(chan2dev(chan), "Dma bus width not supported\n");
233 return -EINVAL;
234 }
235 }
236
237 static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
238 {
239 switch (maxburst) {
240 case 0:
241 case 1:
242 return STM32_DMA_BURST_SINGLE;
243 case 4:
244 return STM32_DMA_BURST_INCR4;
245 case 8:
246 return STM32_DMA_BURST_INCR8;
247 case 16:
248 return STM32_DMA_BURST_INCR16;
249 default:
250 dev_err(chan2dev(chan), "Dma burst size not supported\n");
251 return -EINVAL;
252 }
253 }
254
255 static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
256 u32 src_maxburst, u32 dst_maxburst)
257 {
258 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
259 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
260
261 if ((!src_maxburst) && (!dst_maxburst)) {
262 /* Using direct mode */
263 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
264 } else {
265 /* Using FIFO mode */
266 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
267 }
268 }
269
270 static int stm32_dma_slave_config(struct dma_chan *c,
271 struct dma_slave_config *config)
272 {
273 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
274
275 memcpy(&chan->dma_sconfig, config, sizeof(*config));
276
277 chan->config_init = true;
278
279 return 0;
280 }
281
282 static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
283 {
284 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
285 u32 flags, dma_isr;
286
287 /*
288 * Read "flags" from DMA_xISR register corresponding to the selected
289 * DMA channel at the correct bit offset inside that register.
290 *
291 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
292 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
293 */
294
295 if (chan->id & 4)
296 dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR);
297 else
298 dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR);
299
300 flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
301
302 return flags;
303 }
304
305 static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
306 {
307 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
308 u32 dma_ifcr;
309
310 /*
311 * Write "flags" to the DMA_xIFCR register corresponding to the selected
312 * DMA channel at the correct bit offset inside that register.
313 *
314 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
315 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
316 */
317 dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
318
319 if (chan->id & 4)
320 stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr);
321 else
322 stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr);
323 }
324
325 static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
326 {
327 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
328 unsigned long timeout = jiffies + msecs_to_jiffies(5000);
329 u32 dma_scr, id;
330
331 id = chan->id;
332 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
333
334 if (dma_scr & STM32_DMA_SCR_EN) {
335 dma_scr &= ~STM32_DMA_SCR_EN;
336 stm32_dma_write(dmadev, STM32_DMA_SCR(id), dma_scr);
337
338 do {
339 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
340 dma_scr &= STM32_DMA_SCR_EN;
341 if (!dma_scr)
342 break;
343
344 if (time_after_eq(jiffies, timeout)) {
345 dev_err(chan2dev(chan), "%s: timeout!\n",
346 __func__);
347 return -EBUSY;
348 }
349 cond_resched();
350 } while (1);
351 }
352
353 return 0;
354 }
355
356 static void stm32_dma_stop(struct stm32_dma_chan *chan)
357 {
358 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
359 u32 dma_scr, dma_sfcr, status;
360 int ret;
361
362 /* Disable interrupts */
363 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
364 dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
365 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
366 dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
367 dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
368 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
369
370 /* Disable DMA */
371 ret = stm32_dma_disable_chan(chan);
372 if (ret < 0)
373 return;
374
375 /* Clear interrupt status if it is there */
376 status = stm32_dma_irq_status(chan);
377 if (status) {
378 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
379 __func__, status);
380 stm32_dma_irq_clear(chan, status);
381 }
382
383 chan->busy = false;
384 }
385
386 static int stm32_dma_terminate_all(struct dma_chan *c)
387 {
388 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
389 unsigned long flags;
390 LIST_HEAD(head);
391
392 spin_lock_irqsave(&chan->vchan.lock, flags);
393
394 if (chan->busy) {
395 stm32_dma_stop(chan);
396 chan->desc = NULL;
397 }
398
399 vchan_get_all_descriptors(&chan->vchan, &head);
400 spin_unlock_irqrestore(&chan->vchan.lock, flags);
401 vchan_dma_desc_free_list(&chan->vchan, &head);
402
403 return 0;
404 }
405
406 static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
407 {
408 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
409 u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
410 u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
411 u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
412 u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
413 u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
414 u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
415
416 dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr);
417 dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr);
418 dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar);
419 dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
420 dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
421 dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
422 }
423
424 static int stm32_dma_start_transfer(struct stm32_dma_chan *chan)
425 {
426 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
427 struct virt_dma_desc *vdesc;
428 struct stm32_dma_sg_req *sg_req;
429 struct stm32_dma_chan_reg *reg;
430 u32 status;
431 int ret;
432
433 ret = stm32_dma_disable_chan(chan);
434 if (ret < 0)
435 return ret;
436
437 if (!chan->desc) {
438 vdesc = vchan_next_desc(&chan->vchan);
439 if (!vdesc)
440 return -EPERM;
441
442 chan->desc = to_stm32_dma_desc(vdesc);
443 chan->next_sg = 0;
444 }
445
446 if (chan->next_sg == chan->desc->num_sgs)
447 chan->next_sg = 0;
448
449 sg_req = &chan->desc->sg_req[chan->next_sg];
450 reg = &sg_req->chan_reg;
451
452 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
453 stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
454 stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
455 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
456 stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
457 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
458
459 chan->next_sg++;
460
461 /* Clear interrupt status if it is there */
462 status = stm32_dma_irq_status(chan);
463 if (status)
464 stm32_dma_irq_clear(chan, status);
465
466 stm32_dma_dump_reg(chan);
467
468 /* Start DMA */
469 reg->dma_scr |= STM32_DMA_SCR_EN;
470 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
471
472 chan->busy = true;
473
474 return 0;
475 }
476
477 static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
478 {
479 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
480 struct stm32_dma_sg_req *sg_req;
481 u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
482
483 id = chan->id;
484 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
485
486 if (dma_scr & STM32_DMA_SCR_DBM) {
487 if (chan->next_sg == chan->desc->num_sgs)
488 chan->next_sg = 0;
489
490 sg_req = &chan->desc->sg_req[chan->next_sg];
491
492 if (dma_scr & STM32_DMA_SCR_CT) {
493 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
494 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
495 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
496 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
497 } else {
498 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
499 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
500 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
501 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
502 }
503
504 chan->next_sg++;
505 }
506 }
507
508 static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
509 {
510 if (chan->desc) {
511 if (chan->desc->cyclic) {
512 vchan_cyclic_callback(&chan->desc->vdesc);
513 stm32_dma_configure_next_sg(chan);
514 } else {
515 chan->busy = false;
516 if (chan->next_sg == chan->desc->num_sgs) {
517 list_del(&chan->desc->vdesc.node);
518 vchan_cookie_complete(&chan->desc->vdesc);
519 chan->desc = NULL;
520 }
521 stm32_dma_start_transfer(chan);
522 }
523 }
524 }
525
526 static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
527 {
528 struct stm32_dma_chan *chan = devid;
529 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
530 u32 status, scr, sfcr;
531
532 spin_lock(&chan->vchan.lock);
533
534 status = stm32_dma_irq_status(chan);
535 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
536 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
537
538 if ((status & STM32_DMA_TCI) && (scr & STM32_DMA_SCR_TCIE)) {
539 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
540 stm32_dma_handle_chan_done(chan);
541
542 } else {
543 stm32_dma_irq_clear(chan, status);
544 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
545 }
546
547 spin_unlock(&chan->vchan.lock);
548
549 return IRQ_HANDLED;
550 }
551
552 static void stm32_dma_issue_pending(struct dma_chan *c)
553 {
554 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
555 unsigned long flags;
556 int ret;
557
558 spin_lock_irqsave(&chan->vchan.lock, flags);
559 if (!chan->busy) {
560 if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
561 ret = stm32_dma_start_transfer(chan);
562 if ((!ret) && (chan->desc->cyclic))
563 stm32_dma_configure_next_sg(chan);
564 }
565 }
566 spin_unlock_irqrestore(&chan->vchan.lock, flags);
567 }
568
569 static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
570 enum dma_transfer_direction direction,
571 enum dma_slave_buswidth *buswidth)
572 {
573 enum dma_slave_buswidth src_addr_width, dst_addr_width;
574 int src_bus_width, dst_bus_width;
575 int src_burst_size, dst_burst_size;
576 u32 src_maxburst, dst_maxburst;
577 dma_addr_t src_addr, dst_addr;
578 u32 dma_scr = 0;
579
580 src_addr_width = chan->dma_sconfig.src_addr_width;
581 dst_addr_width = chan->dma_sconfig.dst_addr_width;
582 src_maxburst = chan->dma_sconfig.src_maxburst;
583 dst_maxburst = chan->dma_sconfig.dst_maxburst;
584 src_addr = chan->dma_sconfig.src_addr;
585 dst_addr = chan->dma_sconfig.dst_addr;
586
587 switch (direction) {
588 case DMA_MEM_TO_DEV:
589 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
590 if (dst_bus_width < 0)
591 return dst_bus_width;
592
593 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
594 if (dst_burst_size < 0)
595 return dst_burst_size;
596
597 if (!src_addr_width)
598 src_addr_width = dst_addr_width;
599
600 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
601 if (src_bus_width < 0)
602 return src_bus_width;
603
604 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
605 if (src_burst_size < 0)
606 return src_burst_size;
607
608 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
609 STM32_DMA_SCR_PSIZE(dst_bus_width) |
610 STM32_DMA_SCR_MSIZE(src_bus_width) |
611 STM32_DMA_SCR_PBURST(dst_burst_size) |
612 STM32_DMA_SCR_MBURST(src_burst_size);
613
614 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
615 *buswidth = dst_addr_width;
616 break;
617
618 case DMA_DEV_TO_MEM:
619 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
620 if (src_bus_width < 0)
621 return src_bus_width;
622
623 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
624 if (src_burst_size < 0)
625 return src_burst_size;
626
627 if (!dst_addr_width)
628 dst_addr_width = src_addr_width;
629
630 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
631 if (dst_bus_width < 0)
632 return dst_bus_width;
633
634 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
635 if (dst_burst_size < 0)
636 return dst_burst_size;
637
638 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
639 STM32_DMA_SCR_PSIZE(src_bus_width) |
640 STM32_DMA_SCR_MSIZE(dst_bus_width) |
641 STM32_DMA_SCR_PBURST(src_burst_size) |
642 STM32_DMA_SCR_MBURST(dst_burst_size);
643
644 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
645 *buswidth = chan->dma_sconfig.src_addr_width;
646 break;
647
648 default:
649 dev_err(chan2dev(chan), "Dma direction is not supported\n");
650 return -EINVAL;
651 }
652
653 stm32_dma_set_fifo_config(chan, src_maxburst, dst_maxburst);
654
655 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
656 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
657 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
658 chan->chan_reg.dma_scr |= dma_scr;
659
660 return 0;
661 }
662
663 static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
664 {
665 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
666 }
667
668 static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
669 struct dma_chan *c, struct scatterlist *sgl,
670 u32 sg_len, enum dma_transfer_direction direction,
671 unsigned long flags, void *context)
672 {
673 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
674 struct stm32_dma_desc *desc;
675 struct scatterlist *sg;
676 enum dma_slave_buswidth buswidth;
677 u32 nb_data_items;
678 int i, ret;
679
680 if (!chan->config_init) {
681 dev_err(chan2dev(chan), "dma channel is not configured\n");
682 return NULL;
683 }
684
685 if (sg_len < 1) {
686 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
687 return NULL;
688 }
689
690 desc = stm32_dma_alloc_desc(sg_len);
691 if (!desc)
692 return NULL;
693
694 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
695 if (ret < 0)
696 goto err;
697
698 /* Set peripheral flow controller */
699 if (chan->dma_sconfig.device_fc)
700 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
701 else
702 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
703
704 for_each_sg(sgl, sg, sg_len, i) {
705 desc->sg_req[i].len = sg_dma_len(sg);
706
707 nb_data_items = desc->sg_req[i].len / buswidth;
708 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
709 dev_err(chan2dev(chan), "nb items not supported\n");
710 goto err;
711 }
712
713 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
714 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
715 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
716 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
717 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
718 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
719 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
720 }
721
722 desc->num_sgs = sg_len;
723 desc->cyclic = false;
724
725 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
726
727 err:
728 kfree(desc);
729 return NULL;
730 }
731
732 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
733 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
734 size_t period_len, enum dma_transfer_direction direction,
735 unsigned long flags)
736 {
737 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
738 struct stm32_dma_desc *desc;
739 enum dma_slave_buswidth buswidth;
740 u32 num_periods, nb_data_items;
741 int i, ret;
742
743 if (!buf_len || !period_len) {
744 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
745 return NULL;
746 }
747
748 if (!chan->config_init) {
749 dev_err(chan2dev(chan), "dma channel is not configured\n");
750 return NULL;
751 }
752
753 if (buf_len % period_len) {
754 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
755 return NULL;
756 }
757
758 /*
759 * We allow to take more number of requests till DMA is
760 * not started. The driver will loop over all requests.
761 * Once DMA is started then new requests can be queued only after
762 * terminating the DMA.
763 */
764 if (chan->busy) {
765 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
766 return NULL;
767 }
768
769 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
770 if (ret < 0)
771 return NULL;
772
773 nb_data_items = period_len / buswidth;
774 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
775 dev_err(chan2dev(chan), "number of items not supported\n");
776 return NULL;
777 }
778
779 /* Enable Circular mode or double buffer mode */
780 if (buf_len == period_len)
781 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
782 else
783 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
784
785 /* Clear periph ctrl if client set it */
786 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
787
788 num_periods = buf_len / period_len;
789
790 desc = stm32_dma_alloc_desc(num_periods);
791 if (!desc)
792 return NULL;
793
794 for (i = 0; i < num_periods; i++) {
795 desc->sg_req[i].len = period_len;
796
797 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
798 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
799 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
800 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
801 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
802 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
803 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
804 buf_addr += period_len;
805 }
806
807 desc->num_sgs = num_periods;
808 desc->cyclic = true;
809
810 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
811 }
812
813 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
814 struct dma_chan *c, dma_addr_t dest,
815 dma_addr_t src, size_t len, unsigned long flags)
816 {
817 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
818 u32 num_sgs;
819 struct stm32_dma_desc *desc;
820 size_t xfer_count, offset;
821 int i;
822
823 num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS);
824 desc = stm32_dma_alloc_desc(num_sgs);
825 if (!desc)
826 return NULL;
827
828 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
829 xfer_count = min_t(size_t, len - offset,
830 STM32_DMA_MAX_DATA_ITEMS);
831
832 desc->sg_req[i].len = xfer_count;
833
834 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
835 desc->sg_req[i].chan_reg.dma_scr =
836 STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
837 STM32_DMA_SCR_MINC |
838 STM32_DMA_SCR_PINC |
839 STM32_DMA_SCR_TCIE |
840 STM32_DMA_SCR_TEIE;
841 desc->sg_req[i].chan_reg.dma_sfcr = STM32_DMA_SFCR_DMDIS |
842 STM32_DMA_SFCR_FTH(STM32_DMA_FIFO_THRESHOLD_FULL) |
843 STM32_DMA_SFCR_FEIE;
844 desc->sg_req[i].chan_reg.dma_spar = src + offset;
845 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
846 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
847 }
848
849 desc->num_sgs = num_sgs;
850 desc->cyclic = false;
851
852 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
853 }
854
855 static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
856 struct stm32_dma_desc *desc,
857 u32 next_sg)
858 {
859 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
860 u32 dma_scr, width, residue, count;
861 int i;
862
863 residue = 0;
864
865 for (i = next_sg; i < desc->num_sgs; i++)
866 residue += desc->sg_req[i].len;
867
868 if (next_sg != 0) {
869 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
870 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
871 count = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
872
873 residue += count << width;
874 }
875
876 return residue;
877 }
878
879 static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
880 dma_cookie_t cookie,
881 struct dma_tx_state *state)
882 {
883 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
884 struct virt_dma_desc *vdesc;
885 enum dma_status status;
886 unsigned long flags;
887 u32 residue;
888
889 status = dma_cookie_status(c, cookie, state);
890 if ((status == DMA_COMPLETE) || (!state))
891 return status;
892
893 spin_lock_irqsave(&chan->vchan.lock, flags);
894 vdesc = vchan_find_desc(&chan->vchan, cookie);
895 if (cookie == chan->desc->vdesc.tx.cookie) {
896 residue = stm32_dma_desc_residue(chan, chan->desc,
897 chan->next_sg);
898 } else if (vdesc) {
899 residue = stm32_dma_desc_residue(chan,
900 to_stm32_dma_desc(vdesc), 0);
901 } else {
902 residue = 0;
903 }
904
905 dma_set_residue(state, residue);
906
907 spin_unlock_irqrestore(&chan->vchan.lock, flags);
908
909 return status;
910 }
911
912 static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
913 {
914 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
915 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
916 int ret;
917
918 chan->config_init = false;
919 ret = clk_prepare_enable(dmadev->clk);
920 if (ret < 0) {
921 dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
922 return ret;
923 }
924
925 ret = stm32_dma_disable_chan(chan);
926 if (ret < 0)
927 clk_disable_unprepare(dmadev->clk);
928
929 return ret;
930 }
931
932 static void stm32_dma_free_chan_resources(struct dma_chan *c)
933 {
934 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
935 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
936 unsigned long flags;
937
938 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
939
940 if (chan->busy) {
941 spin_lock_irqsave(&chan->vchan.lock, flags);
942 stm32_dma_stop(chan);
943 chan->desc = NULL;
944 spin_unlock_irqrestore(&chan->vchan.lock, flags);
945 }
946
947 clk_disable_unprepare(dmadev->clk);
948
949 vchan_free_chan_resources(to_virt_chan(c));
950 }
951
952 static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
953 {
954 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
955 }
956
957 void stm32_dma_set_config(struct stm32_dma_chan *chan,
958 struct stm32_dma_cfg *cfg)
959 {
960 stm32_dma_clear_reg(&chan->chan_reg);
961
962 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
963 chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
964
965 /* Enable Interrupts */
966 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
967
968 chan->chan_reg.dma_sfcr = cfg->threshold & STM32_DMA_SFCR_FTH_MASK;
969 }
970
971 static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
972 struct of_dma *ofdma)
973 {
974 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
975 struct stm32_dma_cfg cfg;
976 struct stm32_dma_chan *chan;
977 struct dma_chan *c;
978
979 if (dma_spec->args_count < 3)
980 return NULL;
981
982 cfg.channel_id = dma_spec->args[0];
983 cfg.request_line = dma_spec->args[1];
984 cfg.stream_config = dma_spec->args[2];
985 cfg.threshold = 0;
986
987 if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >=
988 STM32_DMA_MAX_REQUEST_ID))
989 return NULL;
990
991 if (dma_spec->args_count > 3)
992 cfg.threshold = dma_spec->args[3];
993
994 chan = &dmadev->chan[cfg.channel_id];
995
996 c = dma_get_slave_channel(&chan->vchan.chan);
997 if (c)
998 stm32_dma_set_config(chan, &cfg);
999
1000 return c;
1001 }
1002
1003 static const struct of_device_id stm32_dma_of_match[] = {
1004 { .compatible = "st,stm32-dma", },
1005 { /* sentinel */ },
1006 };
1007 MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1008
1009 static int stm32_dma_probe(struct platform_device *pdev)
1010 {
1011 struct stm32_dma_chan *chan;
1012 struct stm32_dma_device *dmadev;
1013 struct dma_device *dd;
1014 const struct of_device_id *match;
1015 struct resource *res;
1016 int i, ret;
1017
1018 match = of_match_device(stm32_dma_of_match, &pdev->dev);
1019 if (!match) {
1020 dev_err(&pdev->dev, "Error: No device match found\n");
1021 return -ENODEV;
1022 }
1023
1024 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1025 if (!dmadev)
1026 return -ENOMEM;
1027
1028 dd = &dmadev->ddev;
1029
1030 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1031 dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1032 if (IS_ERR(dmadev->base))
1033 return PTR_ERR(dmadev->base);
1034
1035 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1036 if (IS_ERR(dmadev->clk)) {
1037 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1038 return PTR_ERR(dmadev->clk);
1039 }
1040
1041 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1042 "st,mem2mem");
1043
1044 dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
1045 if (!IS_ERR(dmadev->rst)) {
1046 reset_control_assert(dmadev->rst);
1047 udelay(2);
1048 reset_control_deassert(dmadev->rst);
1049 }
1050
1051 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1052 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1053 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1054 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1055 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1056 dd->device_tx_status = stm32_dma_tx_status;
1057 dd->device_issue_pending = stm32_dma_issue_pending;
1058 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1059 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1060 dd->device_config = stm32_dma_slave_config;
1061 dd->device_terminate_all = stm32_dma_terminate_all;
1062 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1063 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1064 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1065 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1066 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1067 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1068 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1069 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1070 dd->dev = &pdev->dev;
1071 INIT_LIST_HEAD(&dd->channels);
1072
1073 if (dmadev->mem2mem) {
1074 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1075 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1076 dd->directions |= BIT(DMA_MEM_TO_MEM);
1077 }
1078
1079 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1080 chan = &dmadev->chan[i];
1081 chan->id = i;
1082 chan->vchan.desc_free = stm32_dma_desc_free;
1083 vchan_init(&chan->vchan, dd);
1084 }
1085
1086 ret = dma_async_device_register(dd);
1087 if (ret)
1088 return ret;
1089
1090 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1091 chan = &dmadev->chan[i];
1092 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1093 if (!res) {
1094 ret = -EINVAL;
1095 dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1096 goto err_unregister;
1097 }
1098 chan->irq = res->start;
1099 ret = devm_request_irq(&pdev->dev, chan->irq,
1100 stm32_dma_chan_irq, 0,
1101 dev_name(chan2dev(chan)), chan);
1102 if (ret) {
1103 dev_err(&pdev->dev,
1104 "request_irq failed with err %d channel %d\n",
1105 ret, i);
1106 goto err_unregister;
1107 }
1108 }
1109
1110 ret = of_dma_controller_register(pdev->dev.of_node,
1111 stm32_dma_of_xlate, dmadev);
1112 if (ret < 0) {
1113 dev_err(&pdev->dev,
1114 "STM32 DMA DMA OF registration failed %d\n", ret);
1115 goto err_unregister;
1116 }
1117
1118 platform_set_drvdata(pdev, dmadev);
1119
1120 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1121
1122 return 0;
1123
1124 err_unregister:
1125 dma_async_device_unregister(dd);
1126
1127 return ret;
1128 }
1129
1130 static struct platform_driver stm32_dma_driver = {
1131 .driver = {
1132 .name = "stm32-dma",
1133 .of_match_table = stm32_dma_of_match,
1134 },
1135 };
1136
1137 static int __init stm32_dma_init(void)
1138 {
1139 return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
1140 }
1141 subsys_initcall(stm32_dma_init);
Linux with added FPC-III support