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[mirror_ubuntu-bionic-kernel.git] / drivers / dma / stm32-dma.c
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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 *
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
119enum stm32_dma_width {
120 STM32_DMA_BYTE,
121 STM32_DMA_HALF_WORD,
122 STM32_DMA_WORD,
123};
124
125enum 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
132struct stm32_dma_cfg {
133 u32 channel_id;
134 u32 request_line;
135 u32 stream_config;
136 u32 threshold;
137};
138
139struct 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
152struct stm32_dma_sg_req {
153 u32 len;
154 struct stm32_dma_chan_reg chan_reg;
155};
156
157struct 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
164struct 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
176struct 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
185static 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
191static 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
196static 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
201static struct device *chan2dev(struct stm32_dma_chan *chan)
202{
203 return &chan->vchan.chan.dev->device;
204}
205
206static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
207{
208 return readl_relaxed(dmadev->base + reg);
209}
210
211static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
212{
213 writel_relaxed(val, dmadev->base + reg);
214}
215
216static 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
222static 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
238static 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
256static 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
271static 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
283static 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
306static 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
326static 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
357static 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
387static 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
407static 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
414static 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
432static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan);
433
434static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
435{
436 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
437 struct virt_dma_desc *vdesc;
438 struct stm32_dma_sg_req *sg_req;
439 struct stm32_dma_chan_reg *reg;
440 u32 status;
441 int ret;
442
443 ret = stm32_dma_disable_chan(chan);
444 if (ret < 0)
445 return;
446
447 if (!chan->desc) {
448 vdesc = vchan_next_desc(&chan->vchan);
449 if (!vdesc)
450 return;
451
452 chan->desc = to_stm32_dma_desc(vdesc);
453 chan->next_sg = 0;
454 }
455
456 if (chan->next_sg == chan->desc->num_sgs)
457 chan->next_sg = 0;
458
459 sg_req = &chan->desc->sg_req[chan->next_sg];
460 reg = &sg_req->chan_reg;
461
462 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
463 stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
464 stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
465 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
466 stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
467 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
468
469 chan->next_sg++;
470
471 /* Clear interrupt status if it is there */
472 status = stm32_dma_irq_status(chan);
473 if (status)
474 stm32_dma_irq_clear(chan, status);
475
476 if (chan->desc->cyclic)
477 stm32_dma_configure_next_sg(chan);
478
479 stm32_dma_dump_reg(chan);
480
481 /* Start DMA */
482 reg->dma_scr |= STM32_DMA_SCR_EN;
483 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
484
485 chan->busy = true;
486
487 dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);
488}
489
490static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
491{
492 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
493 struct stm32_dma_sg_req *sg_req;
494 u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
495
496 id = chan->id;
497 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
498
499 if (dma_scr & STM32_DMA_SCR_DBM) {
500 if (chan->next_sg == chan->desc->num_sgs)
501 chan->next_sg = 0;
502
503 sg_req = &chan->desc->sg_req[chan->next_sg];
504
505 if (dma_scr & STM32_DMA_SCR_CT) {
506 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
507 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
508 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
509 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
510 } else {
511 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
512 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
513 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
514 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
515 }
516 }
517}
518
519static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
520{
521 if (chan->desc) {
522 if (chan->desc->cyclic) {
523 vchan_cyclic_callback(&chan->desc->vdesc);
524 chan->next_sg++;
525 stm32_dma_configure_next_sg(chan);
526 } else {
527 chan->busy = false;
528 if (chan->next_sg == chan->desc->num_sgs) {
529 list_del(&chan->desc->vdesc.node);
530 vchan_cookie_complete(&chan->desc->vdesc);
531 chan->desc = NULL;
532 }
533 stm32_dma_start_transfer(chan);
534 }
535 }
536}
537
538static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
539{
540 struct stm32_dma_chan *chan = devid;
541 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
542 u32 status, scr;
543
544 spin_lock(&chan->vchan.lock);
545
546 status = stm32_dma_irq_status(chan);
547 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
548
549 if ((status & STM32_DMA_TCI) && (scr & STM32_DMA_SCR_TCIE)) {
550 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
551 stm32_dma_handle_chan_done(chan);
552
553 } else {
554 stm32_dma_irq_clear(chan, status);
555 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
556 }
557
558 spin_unlock(&chan->vchan.lock);
559
560 return IRQ_HANDLED;
561}
562
563static void stm32_dma_issue_pending(struct dma_chan *c)
564{
565 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
566 unsigned long flags;
567
568 spin_lock_irqsave(&chan->vchan.lock, flags);
569 if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
570 dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
571 stm32_dma_start_transfer(chan);
572
573 }
574 spin_unlock_irqrestore(&chan->vchan.lock, flags);
575}
576
577static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
578 enum dma_transfer_direction direction,
579 enum dma_slave_buswidth *buswidth)
580{
581 enum dma_slave_buswidth src_addr_width, dst_addr_width;
582 int src_bus_width, dst_bus_width;
583 int src_burst_size, dst_burst_size;
584 u32 src_maxburst, dst_maxburst;
585 u32 dma_scr = 0;
586
587 src_addr_width = chan->dma_sconfig.src_addr_width;
588 dst_addr_width = chan->dma_sconfig.dst_addr_width;
589 src_maxburst = chan->dma_sconfig.src_maxburst;
590 dst_maxburst = chan->dma_sconfig.dst_maxburst;
591
592 switch (direction) {
593 case DMA_MEM_TO_DEV:
594 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
595 if (dst_bus_width < 0)
596 return dst_bus_width;
597
598 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
599 if (dst_burst_size < 0)
600 return dst_burst_size;
601
602 if (!src_addr_width)
603 src_addr_width = dst_addr_width;
604
605 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
606 if (src_bus_width < 0)
607 return src_bus_width;
608
609 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
610 if (src_burst_size < 0)
611 return src_burst_size;
612
613 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
614 STM32_DMA_SCR_PSIZE(dst_bus_width) |
615 STM32_DMA_SCR_MSIZE(src_bus_width) |
616 STM32_DMA_SCR_PBURST(dst_burst_size) |
617 STM32_DMA_SCR_MBURST(src_burst_size);
618
619 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
620 *buswidth = dst_addr_width;
621 break;
622
623 case DMA_DEV_TO_MEM:
624 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
625 if (src_bus_width < 0)
626 return src_bus_width;
627
628 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
629 if (src_burst_size < 0)
630 return src_burst_size;
631
632 if (!dst_addr_width)
633 dst_addr_width = src_addr_width;
634
635 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
636 if (dst_bus_width < 0)
637 return dst_bus_width;
638
639 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
640 if (dst_burst_size < 0)
641 return dst_burst_size;
642
643 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
644 STM32_DMA_SCR_PSIZE(src_bus_width) |
645 STM32_DMA_SCR_MSIZE(dst_bus_width) |
646 STM32_DMA_SCR_PBURST(src_burst_size) |
647 STM32_DMA_SCR_MBURST(dst_burst_size);
648
649 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
650 *buswidth = chan->dma_sconfig.src_addr_width;
651 break;
652
653 default:
654 dev_err(chan2dev(chan), "Dma direction is not supported\n");
655 return -EINVAL;
656 }
657
658 stm32_dma_set_fifo_config(chan, src_maxburst, dst_maxburst);
659
660 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
661 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
662 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
663 chan->chan_reg.dma_scr |= dma_scr;
664
665 return 0;
666}
667
668static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
669{
670 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
671}
672
673static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
674 struct dma_chan *c, struct scatterlist *sgl,
675 u32 sg_len, enum dma_transfer_direction direction,
676 unsigned long flags, void *context)
677{
678 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
679 struct stm32_dma_desc *desc;
680 struct scatterlist *sg;
681 enum dma_slave_buswidth buswidth;
682 u32 nb_data_items;
683 int i, ret;
684
685 if (!chan->config_init) {
686 dev_err(chan2dev(chan), "dma channel is not configured\n");
687 return NULL;
688 }
689
690 if (sg_len < 1) {
691 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
692 return NULL;
693 }
694
695 desc = stm32_dma_alloc_desc(sg_len);
696 if (!desc)
697 return NULL;
698
699 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
700 if (ret < 0)
701 goto err;
702
703 /* Set peripheral flow controller */
704 if (chan->dma_sconfig.device_fc)
705 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
706 else
707 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
708
709 for_each_sg(sgl, sg, sg_len, i) {
710 desc->sg_req[i].len = sg_dma_len(sg);
711
712 nb_data_items = desc->sg_req[i].len / buswidth;
713 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
714 dev_err(chan2dev(chan), "nb items not supported\n");
715 goto err;
716 }
717
718 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
719 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
720 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
721 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
722 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
723 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
724 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
725 }
726
727 desc->num_sgs = sg_len;
728 desc->cyclic = false;
729
730 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
731
732err:
733 kfree(desc);
734 return NULL;
735}
736
737static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
738 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
739 size_t period_len, enum dma_transfer_direction direction,
740 unsigned long flags)
741{
742 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
743 struct stm32_dma_desc *desc;
744 enum dma_slave_buswidth buswidth;
745 u32 num_periods, nb_data_items;
746 int i, ret;
747
748 if (!buf_len || !period_len) {
749 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
750 return NULL;
751 }
752
753 if (!chan->config_init) {
754 dev_err(chan2dev(chan), "dma channel is not configured\n");
755 return NULL;
756 }
757
758 if (buf_len % period_len) {
759 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
760 return NULL;
761 }
762
763 /*
764 * We allow to take more number of requests till DMA is
765 * not started. The driver will loop over all requests.
766 * Once DMA is started then new requests can be queued only after
767 * terminating the DMA.
768 */
769 if (chan->busy) {
770 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
771 return NULL;
772 }
773
774 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
775 if (ret < 0)
776 return NULL;
777
778 nb_data_items = period_len / buswidth;
779 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
780 dev_err(chan2dev(chan), "number of items not supported\n");
781 return NULL;
782 }
783
784 /* Enable Circular mode or double buffer mode */
785 if (buf_len == period_len)
786 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
787 else
788 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
789
790 /* Clear periph ctrl if client set it */
791 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
792
793 num_periods = buf_len / period_len;
794
795 desc = stm32_dma_alloc_desc(num_periods);
796 if (!desc)
797 return NULL;
798
799 for (i = 0; i < num_periods; i++) {
800 desc->sg_req[i].len = period_len;
801
802 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
803 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
804 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
805 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
806 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
807 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
808 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
809 buf_addr += period_len;
810 }
811
812 desc->num_sgs = num_periods;
813 desc->cyclic = true;
814
815 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
816}
817
818static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
819 struct dma_chan *c, dma_addr_t dest,
820 dma_addr_t src, size_t len, unsigned long flags)
821{
822 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
823 u32 num_sgs;
824 struct stm32_dma_desc *desc;
825 size_t xfer_count, offset;
826 int i;
827
828 num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS);
829 desc = stm32_dma_alloc_desc(num_sgs);
830 if (!desc)
831 return NULL;
832
833 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
834 xfer_count = min_t(size_t, len - offset,
835 STM32_DMA_MAX_DATA_ITEMS);
836
837 desc->sg_req[i].len = xfer_count;
838
839 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
840 desc->sg_req[i].chan_reg.dma_scr =
841 STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
842 STM32_DMA_SCR_MINC |
843 STM32_DMA_SCR_PINC |
844 STM32_DMA_SCR_TCIE |
845 STM32_DMA_SCR_TEIE;
846 desc->sg_req[i].chan_reg.dma_sfcr = STM32_DMA_SFCR_DMDIS |
847 STM32_DMA_SFCR_FTH(STM32_DMA_FIFO_THRESHOLD_FULL) |
848 STM32_DMA_SFCR_FEIE;
849 desc->sg_req[i].chan_reg.dma_spar = src + offset;
850 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
851 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
852 }
853
854 desc->num_sgs = num_sgs;
855 desc->cyclic = false;
856
857 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
858}
859
860static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
861{
862 u32 dma_scr, width, ndtr;
863 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
864
865 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
866 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
867 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
868
869 return ndtr << width;
870}
871
872static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
873 struct stm32_dma_desc *desc,
874 u32 next_sg)
875{
876 u32 residue = 0;
877 int i;
878
879 /*
880 * In cyclic mode, for the last period, residue = remaining bytes from
881 * NDTR
882 */
883 if (chan->desc->cyclic && next_sg == 0)
884 return stm32_dma_get_remaining_bytes(chan);
885
886 /*
887 * For all other periods in cyclic mode, and in sg mode,
888 * residue = remaining bytes from NDTR + remaining periods/sg to be
889 * transferred
890 */
891 for (i = next_sg; i < desc->num_sgs; i++)
892 residue += desc->sg_req[i].len;
893 residue += stm32_dma_get_remaining_bytes(chan);
894
895 return residue;
896}
897
898static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
899 dma_cookie_t cookie,
900 struct dma_tx_state *state)
901{
902 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
903 struct virt_dma_desc *vdesc;
904 enum dma_status status;
905 unsigned long flags;
906 u32 residue = 0;
907
908 status = dma_cookie_status(c, cookie, state);
909 if ((status == DMA_COMPLETE) || (!state))
910 return status;
911
912 spin_lock_irqsave(&chan->vchan.lock, flags);
913 vdesc = vchan_find_desc(&chan->vchan, cookie);
914 if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
915 residue = stm32_dma_desc_residue(chan, chan->desc,
916 chan->next_sg);
917 else if (vdesc)
918 residue = stm32_dma_desc_residue(chan,
919 to_stm32_dma_desc(vdesc), 0);
920 dma_set_residue(state, residue);
921
922 spin_unlock_irqrestore(&chan->vchan.lock, flags);
923
924 return status;
925}
926
927static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
928{
929 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
930 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
931 int ret;
932
933 chan->config_init = false;
934 ret = clk_prepare_enable(dmadev->clk);
935 if (ret < 0) {
936 dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
937 return ret;
938 }
939
940 ret = stm32_dma_disable_chan(chan);
941 if (ret < 0)
942 clk_disable_unprepare(dmadev->clk);
943
944 return ret;
945}
946
947static void stm32_dma_free_chan_resources(struct dma_chan *c)
948{
949 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
950 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
951 unsigned long flags;
952
953 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
954
955 if (chan->busy) {
956 spin_lock_irqsave(&chan->vchan.lock, flags);
957 stm32_dma_stop(chan);
958 chan->desc = NULL;
959 spin_unlock_irqrestore(&chan->vchan.lock, flags);
960 }
961
962 clk_disable_unprepare(dmadev->clk);
963
964 vchan_free_chan_resources(to_virt_chan(c));
965}
966
967static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
968{
969 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
970}
971
972static void stm32_dma_set_config(struct stm32_dma_chan *chan,
973 struct stm32_dma_cfg *cfg)
974{
975 stm32_dma_clear_reg(&chan->chan_reg);
976
977 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
978 chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
979
980 /* Enable Interrupts */
981 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
982
983 chan->chan_reg.dma_sfcr = cfg->threshold & STM32_DMA_SFCR_FTH_MASK;
984}
985
986static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
987 struct of_dma *ofdma)
988{
989 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
990 struct device *dev = dmadev->ddev.dev;
991 struct stm32_dma_cfg cfg;
992 struct stm32_dma_chan *chan;
993 struct dma_chan *c;
994
995 if (dma_spec->args_count < 4) {
996 dev_err(dev, "Bad number of cells\n");
997 return NULL;
998 }
999
1000 cfg.channel_id = dma_spec->args[0];
1001 cfg.request_line = dma_spec->args[1];
1002 cfg.stream_config = dma_spec->args[2];
1003 cfg.threshold = dma_spec->args[3];
1004
1005 if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) ||
1006 (cfg.request_line >= STM32_DMA_MAX_REQUEST_ID)) {
1007 dev_err(dev, "Bad channel and/or request id\n");
1008 return NULL;
1009 }
1010
1011 chan = &dmadev->chan[cfg.channel_id];
1012
1013 c = dma_get_slave_channel(&chan->vchan.chan);
1014 if (!c) {
1015 dev_err(dev, "No more channels available\n");
1016 return NULL;
1017 }
1018
1019 stm32_dma_set_config(chan, &cfg);
1020
1021 return c;
1022}
1023
1024static const struct of_device_id stm32_dma_of_match[] = {
1025 { .compatible = "st,stm32-dma", },
1026 { /* sentinel */ },
1027};
1028MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1029
1030static int stm32_dma_probe(struct platform_device *pdev)
1031{
1032 struct stm32_dma_chan *chan;
1033 struct stm32_dma_device *dmadev;
1034 struct dma_device *dd;
1035 const struct of_device_id *match;
1036 struct resource *res;
1037 int i, ret;
1038
1039 match = of_match_device(stm32_dma_of_match, &pdev->dev);
1040 if (!match) {
1041 dev_err(&pdev->dev, "Error: No device match found\n");
1042 return -ENODEV;
1043 }
1044
1045 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1046 if (!dmadev)
1047 return -ENOMEM;
1048
1049 dd = &dmadev->ddev;
1050
1051 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1052 dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1053 if (IS_ERR(dmadev->base))
1054 return PTR_ERR(dmadev->base);
1055
1056 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1057 if (IS_ERR(dmadev->clk)) {
1058 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1059 return PTR_ERR(dmadev->clk);
1060 }
1061
1062 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1063 "st,mem2mem");
1064
1065 dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
1066 if (!IS_ERR(dmadev->rst)) {
1067 reset_control_assert(dmadev->rst);
1068 udelay(2);
1069 reset_control_deassert(dmadev->rst);
1070 }
1071
1072 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1073 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1074 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1075 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1076 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1077 dd->device_tx_status = stm32_dma_tx_status;
1078 dd->device_issue_pending = stm32_dma_issue_pending;
1079 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1080 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1081 dd->device_config = stm32_dma_slave_config;
1082 dd->device_terminate_all = stm32_dma_terminate_all;
1083 dd->device_synchronize = stm32_dma_synchronize;
1084 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1085 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1086 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1087 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1088 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1089 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1090 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1091 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1092 dd->max_burst = STM32_DMA_MAX_BURST;
1093 dd->dev = &pdev->dev;
1094 INIT_LIST_HEAD(&dd->channels);
1095
1096 if (dmadev->mem2mem) {
1097 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1098 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1099 dd->directions |= BIT(DMA_MEM_TO_MEM);
1100 }
1101
1102 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1103 chan = &dmadev->chan[i];
1104 chan->id = i;
1105 chan->vchan.desc_free = stm32_dma_desc_free;
1106 vchan_init(&chan->vchan, dd);
1107 }
1108
1109 ret = dma_async_device_register(dd);
1110 if (ret)
1111 return ret;
1112
1113 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1114 chan = &dmadev->chan[i];
1115 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1116 if (!res) {
1117 ret = -EINVAL;
1118 dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1119 goto err_unregister;
1120 }
1121 chan->irq = res->start;
1122 ret = devm_request_irq(&pdev->dev, chan->irq,
1123 stm32_dma_chan_irq, 0,
1124 dev_name(chan2dev(chan)), chan);
1125 if (ret) {
1126 dev_err(&pdev->dev,
1127 "request_irq failed with err %d channel %d\n",
1128 ret, i);
1129 goto err_unregister;
1130 }
1131 }
1132
1133 ret = of_dma_controller_register(pdev->dev.of_node,
1134 stm32_dma_of_xlate, dmadev);
1135 if (ret < 0) {
1136 dev_err(&pdev->dev,
1137 "STM32 DMA DMA OF registration failed %d\n", ret);
1138 goto err_unregister;
1139 }
1140
1141 platform_set_drvdata(pdev, dmadev);
1142
1143 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1144
1145 return 0;
1146
1147err_unregister:
1148 dma_async_device_unregister(dd);
1149
1150 return ret;
1151}
1152
1153static struct platform_driver stm32_dma_driver = {
1154 .driver = {
1155 .name = "stm32-dma",
1156 .of_match_table = stm32_dma_of_match,
1157 },
1158};
1159
1160static int __init stm32_dma_init(void)
1161{
1162 return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
1163}
1164subsys_initcall(stm32_dma_init);
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