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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for STM32 DMA controller
4 *
5 * Inspired by dma-jz4740.c and tegra20-apb-dma.c
6 *
7 * Copyright (C) M'boumba Cedric Madianga 2015
8 * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
9 * Pierre-Yves Mordret <pierre-yves.mordret@st.com>
10 */
11
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/dmaengine.h>
15#include <linux/dma-mapping.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/iopoll.h>
19#include <linux/jiffies.h>
20#include <linux/list.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/of_device.h>
24#include <linux/of_dma.h>
25#include <linux/platform_device.h>
26#include <linux/pm_runtime.h>
27#include <linux/reset.h>
28#include <linux/sched.h>
29#include <linux/slab.h>
30
31#include "virt-dma.h"
32
33#define STM32_DMA_LISR 0x0000 /* DMA Low Int Status Reg */
34#define STM32_DMA_HISR 0x0004 /* DMA High Int Status Reg */
35#define STM32_DMA_LIFCR 0x0008 /* DMA Low Int Flag Clear Reg */
36#define STM32_DMA_HIFCR 0x000c /* DMA High Int Flag Clear Reg */
37#define STM32_DMA_TCI BIT(5) /* Transfer Complete Interrupt */
38#define STM32_DMA_HTI BIT(4) /* Half Transfer Interrupt */
39#define STM32_DMA_TEI BIT(3) /* Transfer Error Interrupt */
40#define STM32_DMA_DMEI BIT(2) /* Direct Mode Error Interrupt */
41#define STM32_DMA_FEI BIT(0) /* FIFO Error Interrupt */
42#define STM32_DMA_MASKI (STM32_DMA_TCI \
43 | STM32_DMA_TEI \
44 | STM32_DMA_DMEI \
45 | STM32_DMA_FEI)
46
47/* DMA Stream x Configuration Register */
48#define STM32_DMA_SCR(x) (0x0010 + 0x18 * (x)) /* x = 0..7 */
49#define STM32_DMA_SCR_REQ(n) ((n & 0x7) << 25)
50#define STM32_DMA_SCR_MBURST_MASK GENMASK(24, 23)
51#define STM32_DMA_SCR_MBURST(n) ((n & 0x3) << 23)
52#define STM32_DMA_SCR_PBURST_MASK GENMASK(22, 21)
53#define STM32_DMA_SCR_PBURST(n) ((n & 0x3) << 21)
54#define STM32_DMA_SCR_PL_MASK GENMASK(17, 16)
55#define STM32_DMA_SCR_PL(n) ((n & 0x3) << 16)
56#define STM32_DMA_SCR_MSIZE_MASK GENMASK(14, 13)
57#define STM32_DMA_SCR_MSIZE(n) ((n & 0x3) << 13)
58#define STM32_DMA_SCR_PSIZE_MASK GENMASK(12, 11)
59#define STM32_DMA_SCR_PSIZE(n) ((n & 0x3) << 11)
60#define STM32_DMA_SCR_PSIZE_GET(n) ((n & STM32_DMA_SCR_PSIZE_MASK) >> 11)
61#define STM32_DMA_SCR_DIR_MASK GENMASK(7, 6)
62#define STM32_DMA_SCR_DIR(n) ((n & 0x3) << 6)
63#define STM32_DMA_SCR_CT BIT(19) /* Target in double buffer */
64#define STM32_DMA_SCR_DBM BIT(18) /* Double Buffer Mode */
65#define STM32_DMA_SCR_PINCOS BIT(15) /* Peripheral inc offset size */
66#define STM32_DMA_SCR_MINC BIT(10) /* Memory increment mode */
67#define STM32_DMA_SCR_PINC BIT(9) /* Peripheral increment mode */
68#define STM32_DMA_SCR_CIRC BIT(8) /* Circular mode */
69#define STM32_DMA_SCR_PFCTRL BIT(5) /* Peripheral Flow Controller */
70#define STM32_DMA_SCR_TCIE BIT(4) /* Transfer Complete Int Enable
71 */
72#define STM32_DMA_SCR_TEIE BIT(2) /* Transfer Error Int Enable */
73#define STM32_DMA_SCR_DMEIE BIT(1) /* Direct Mode Err Int Enable */
74#define STM32_DMA_SCR_EN BIT(0) /* Stream Enable */
75#define STM32_DMA_SCR_CFG_MASK (STM32_DMA_SCR_PINC \
76 | STM32_DMA_SCR_MINC \
77 | STM32_DMA_SCR_PINCOS \
78 | STM32_DMA_SCR_PL_MASK)
79#define STM32_DMA_SCR_IRQ_MASK (STM32_DMA_SCR_TCIE \
80 | STM32_DMA_SCR_TEIE \
81 | STM32_DMA_SCR_DMEIE)
82
83/* DMA Stream x number of data register */
84#define STM32_DMA_SNDTR(x) (0x0014 + 0x18 * (x))
85
86/* DMA stream peripheral address register */
87#define STM32_DMA_SPAR(x) (0x0018 + 0x18 * (x))
88
89/* DMA stream x memory 0 address register */
90#define STM32_DMA_SM0AR(x) (0x001c + 0x18 * (x))
91
92/* DMA stream x memory 1 address register */
93#define STM32_DMA_SM1AR(x) (0x0020 + 0x18 * (x))
94
95/* DMA stream x FIFO control register */
96#define STM32_DMA_SFCR(x) (0x0024 + 0x18 * (x))
97#define STM32_DMA_SFCR_FTH_MASK GENMASK(1, 0)
98#define STM32_DMA_SFCR_FTH(n) (n & STM32_DMA_SFCR_FTH_MASK)
99#define STM32_DMA_SFCR_FEIE BIT(7) /* FIFO error interrupt enable */
100#define STM32_DMA_SFCR_DMDIS BIT(2) /* Direct mode disable */
101#define STM32_DMA_SFCR_MASK (STM32_DMA_SFCR_FEIE \
102 | STM32_DMA_SFCR_DMDIS)
103
104/* DMA direction */
105#define STM32_DMA_DEV_TO_MEM 0x00
106#define STM32_DMA_MEM_TO_DEV 0x01
107#define STM32_DMA_MEM_TO_MEM 0x02
108
109/* DMA priority level */
110#define STM32_DMA_PRIORITY_LOW 0x00
111#define STM32_DMA_PRIORITY_MEDIUM 0x01
112#define STM32_DMA_PRIORITY_HIGH 0x02
113#define STM32_DMA_PRIORITY_VERY_HIGH 0x03
114
115/* DMA FIFO threshold selection */
116#define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL 0x00
117#define STM32_DMA_FIFO_THRESHOLD_HALFFULL 0x01
118#define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL 0x02
119#define STM32_DMA_FIFO_THRESHOLD_FULL 0x03
120#define STM32_DMA_FIFO_THRESHOLD_NONE 0x04
121
122#define STM32_DMA_MAX_DATA_ITEMS 0xffff
123/*
124 * Valid transfer starts from @0 to @0xFFFE leading to unaligned scatter
125 * gather at boundary. Thus it's safer to round down this value on FIFO
126 * size (16 Bytes)
127 */
128#define STM32_DMA_ALIGNED_MAX_DATA_ITEMS \
129 ALIGN_DOWN(STM32_DMA_MAX_DATA_ITEMS, 16)
130#define STM32_DMA_MAX_CHANNELS 0x08
131#define STM32_DMA_MAX_REQUEST_ID 0x08
132#define STM32_DMA_MAX_DATA_PARAM 0x03
133#define STM32_DMA_FIFO_SIZE 16 /* FIFO is 16 bytes */
134#define STM32_DMA_MIN_BURST 4
135#define STM32_DMA_MAX_BURST 16
136
137/* DMA Features */
138#define STM32_DMA_THRESHOLD_FTR_MASK GENMASK(1, 0)
139#define STM32_DMA_THRESHOLD_FTR_GET(n) ((n) & STM32_DMA_THRESHOLD_FTR_MASK)
140#define STM32_DMA_DIRECT_MODE_MASK BIT(2)
141#define STM32_DMA_DIRECT_MODE_GET(n) (((n) & STM32_DMA_DIRECT_MODE_MASK) \
142 >> 2)
143
144enum stm32_dma_width {
145 STM32_DMA_BYTE,
146 STM32_DMA_HALF_WORD,
147 STM32_DMA_WORD,
148};
149
150enum stm32_dma_burst_size {
151 STM32_DMA_BURST_SINGLE,
152 STM32_DMA_BURST_INCR4,
153 STM32_DMA_BURST_INCR8,
154 STM32_DMA_BURST_INCR16,
155};
156
157/**
158 * struct stm32_dma_cfg - STM32 DMA custom configuration
159 * @channel_id: channel ID
160 * @request_line: DMA request
161 * @stream_config: 32bit mask specifying the DMA channel configuration
162 * @features: 32bit mask specifying the DMA Feature list
163 */
164struct stm32_dma_cfg {
165 u32 channel_id;
166 u32 request_line;
167 u32 stream_config;
168 u32 features;
169};
170
171struct stm32_dma_chan_reg {
172 u32 dma_lisr;
173 u32 dma_hisr;
174 u32 dma_lifcr;
175 u32 dma_hifcr;
176 u32 dma_scr;
177 u32 dma_sndtr;
178 u32 dma_spar;
179 u32 dma_sm0ar;
180 u32 dma_sm1ar;
181 u32 dma_sfcr;
182};
183
184struct stm32_dma_sg_req {
185 u32 len;
186 struct stm32_dma_chan_reg chan_reg;
187};
188
189struct stm32_dma_desc {
190 struct virt_dma_desc vdesc;
191 bool cyclic;
192 u32 num_sgs;
193 struct stm32_dma_sg_req sg_req[];
194};
195
196struct stm32_dma_chan {
197 struct virt_dma_chan vchan;
198 bool config_init;
199 bool busy;
200 u32 id;
201 u32 irq;
202 struct stm32_dma_desc *desc;
203 u32 next_sg;
204 struct dma_slave_config dma_sconfig;
205 struct stm32_dma_chan_reg chan_reg;
206 u32 threshold;
207 u32 mem_burst;
208 u32 mem_width;
209};
210
211struct stm32_dma_device {
212 struct dma_device ddev;
213 void __iomem *base;
214 struct clk *clk;
215 bool mem2mem;
216 struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
217};
218
219static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
220{
221 return container_of(chan->vchan.chan.device, struct stm32_dma_device,
222 ddev);
223}
224
225static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
226{
227 return container_of(c, struct stm32_dma_chan, vchan.chan);
228}
229
230static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
231{
232 return container_of(vdesc, struct stm32_dma_desc, vdesc);
233}
234
235static struct device *chan2dev(struct stm32_dma_chan *chan)
236{
237 return &chan->vchan.chan.dev->device;
238}
239
240static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
241{
242 return readl_relaxed(dmadev->base + reg);
243}
244
245static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
246{
247 writel_relaxed(val, dmadev->base + reg);
248}
249
250static int stm32_dma_get_width(struct stm32_dma_chan *chan,
251 enum dma_slave_buswidth width)
252{
253 switch (width) {
254 case DMA_SLAVE_BUSWIDTH_1_BYTE:
255 return STM32_DMA_BYTE;
256 case DMA_SLAVE_BUSWIDTH_2_BYTES:
257 return STM32_DMA_HALF_WORD;
258 case DMA_SLAVE_BUSWIDTH_4_BYTES:
259 return STM32_DMA_WORD;
260 default:
261 dev_err(chan2dev(chan), "Dma bus width not supported\n");
262 return -EINVAL;
263 }
264}
265
266static enum dma_slave_buswidth stm32_dma_get_max_width(u32 buf_len,
267 u32 threshold)
268{
269 enum dma_slave_buswidth max_width;
270
271 if (threshold == STM32_DMA_FIFO_THRESHOLD_FULL)
272 max_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
273 else
274 max_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
275
276 while ((buf_len < max_width || buf_len % max_width) &&
277 max_width > DMA_SLAVE_BUSWIDTH_1_BYTE)
278 max_width = max_width >> 1;
279
280 return max_width;
281}
282
283static bool stm32_dma_fifo_threshold_is_allowed(u32 burst, u32 threshold,
284 enum dma_slave_buswidth width)
285{
286 u32 remaining;
287
288 if (threshold == STM32_DMA_FIFO_THRESHOLD_NONE)
289 return false;
290
291 if (width != DMA_SLAVE_BUSWIDTH_UNDEFINED) {
292 if (burst != 0) {
293 /*
294 * If number of beats fit in several whole bursts
295 * this configuration is allowed.
296 */
297 remaining = ((STM32_DMA_FIFO_SIZE / width) *
298 (threshold + 1) / 4) % burst;
299
300 if (remaining == 0)
301 return true;
302 } else {
303 return true;
304 }
305 }
306
307 return false;
308}
309
310static bool stm32_dma_is_burst_possible(u32 buf_len, u32 threshold)
311{
312 /* If FIFO direct mode, burst is not possible */
313 if (threshold == STM32_DMA_FIFO_THRESHOLD_NONE)
314 return false;
315
316 /*
317 * Buffer or period length has to be aligned on FIFO depth.
318 * Otherwise bytes may be stuck within FIFO at buffer or period
319 * length.
320 */
321 return ((buf_len % ((threshold + 1) * 4)) == 0);
322}
323
324static u32 stm32_dma_get_best_burst(u32 buf_len, u32 max_burst, u32 threshold,
325 enum dma_slave_buswidth width)
326{
327 u32 best_burst = max_burst;
328
329 if (best_burst == 1 || !stm32_dma_is_burst_possible(buf_len, threshold))
330 return 0;
331
332 while ((buf_len < best_burst * width && best_burst > 1) ||
333 !stm32_dma_fifo_threshold_is_allowed(best_burst, threshold,
334 width)) {
335 if (best_burst > STM32_DMA_MIN_BURST)
336 best_burst = best_burst >> 1;
337 else
338 best_burst = 0;
339 }
340
341 return best_burst;
342}
343
344static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
345{
346 switch (maxburst) {
347 case 0:
348 case 1:
349 return STM32_DMA_BURST_SINGLE;
350 case 4:
351 return STM32_DMA_BURST_INCR4;
352 case 8:
353 return STM32_DMA_BURST_INCR8;
354 case 16:
355 return STM32_DMA_BURST_INCR16;
356 default:
357 dev_err(chan2dev(chan), "Dma burst size not supported\n");
358 return -EINVAL;
359 }
360}
361
362static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
363 u32 src_burst, u32 dst_burst)
364{
365 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
366 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
367
368 if (!src_burst && !dst_burst) {
369 /* Using direct mode */
370 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
371 } else {
372 /* Using FIFO mode */
373 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
374 }
375}
376
377static int stm32_dma_slave_config(struct dma_chan *c,
378 struct dma_slave_config *config)
379{
380 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
381
382 memcpy(&chan->dma_sconfig, config, sizeof(*config));
383
384 chan->config_init = true;
385
386 return 0;
387}
388
389static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
390{
391 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
392 u32 flags, dma_isr;
393
394 /*
395 * Read "flags" from DMA_xISR register corresponding to the selected
396 * DMA channel at the correct bit offset inside that register.
397 *
398 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
399 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
400 */
401
402 if (chan->id & 4)
403 dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR);
404 else
405 dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR);
406
407 flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
408
409 return flags & STM32_DMA_MASKI;
410}
411
412static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
413{
414 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
415 u32 dma_ifcr;
416
417 /*
418 * Write "flags" to the DMA_xIFCR register corresponding to the selected
419 * DMA channel at the correct bit offset inside that register.
420 *
421 * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
422 * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
423 */
424 flags &= STM32_DMA_MASKI;
425 dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
426
427 if (chan->id & 4)
428 stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr);
429 else
430 stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr);
431}
432
433static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
434{
435 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
436 u32 dma_scr, id, reg;
437
438 id = chan->id;
439 reg = STM32_DMA_SCR(id);
440 dma_scr = stm32_dma_read(dmadev, reg);
441
442 if (dma_scr & STM32_DMA_SCR_EN) {
443 dma_scr &= ~STM32_DMA_SCR_EN;
444 stm32_dma_write(dmadev, reg, dma_scr);
445
446 return readl_relaxed_poll_timeout_atomic(dmadev->base + reg,
447 dma_scr, !(dma_scr & STM32_DMA_SCR_EN),
448 10, 1000000);
449 }
450
451 return 0;
452}
453
454static void stm32_dma_stop(struct stm32_dma_chan *chan)
455{
456 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
457 u32 dma_scr, dma_sfcr, status;
458 int ret;
459
460 /* Disable interrupts */
461 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
462 dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
463 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
464 dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
465 dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
466 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
467
468 /* Disable DMA */
469 ret = stm32_dma_disable_chan(chan);
470 if (ret < 0)
471 return;
472
473 /* Clear interrupt status if it is there */
474 status = stm32_dma_irq_status(chan);
475 if (status) {
476 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
477 __func__, status);
478 stm32_dma_irq_clear(chan, status);
479 }
480
481 chan->busy = false;
482}
483
484static int stm32_dma_terminate_all(struct dma_chan *c)
485{
486 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
487 unsigned long flags;
488 LIST_HEAD(head);
489
490 spin_lock_irqsave(&chan->vchan.lock, flags);
491
492 if (chan->desc) {
493 vchan_terminate_vdesc(&chan->desc->vdesc);
494 if (chan->busy)
495 stm32_dma_stop(chan);
496 chan->desc = NULL;
497 }
498
499 vchan_get_all_descriptors(&chan->vchan, &head);
500 spin_unlock_irqrestore(&chan->vchan.lock, flags);
501 vchan_dma_desc_free_list(&chan->vchan, &head);
502
503 return 0;
504}
505
506static void stm32_dma_synchronize(struct dma_chan *c)
507{
508 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
509
510 vchan_synchronize(&chan->vchan);
511}
512
513static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
514{
515 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
516 u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
517 u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
518 u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
519 u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
520 u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
521 u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
522
523 dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr);
524 dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr);
525 dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar);
526 dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
527 dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
528 dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
529}
530
531static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan);
532
533static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
534{
535 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
536 struct virt_dma_desc *vdesc;
537 struct stm32_dma_sg_req *sg_req;
538 struct stm32_dma_chan_reg *reg;
539 u32 status;
540 int ret;
541
542 ret = stm32_dma_disable_chan(chan);
543 if (ret < 0)
544 return;
545
546 if (!chan->desc) {
547 vdesc = vchan_next_desc(&chan->vchan);
548 if (!vdesc)
549 return;
550
551 list_del(&vdesc->node);
552
553 chan->desc = to_stm32_dma_desc(vdesc);
554 chan->next_sg = 0;
555 }
556
557 if (chan->next_sg == chan->desc->num_sgs)
558 chan->next_sg = 0;
559
560 sg_req = &chan->desc->sg_req[chan->next_sg];
561 reg = &sg_req->chan_reg;
562
563 reg->dma_scr &= ~STM32_DMA_SCR_EN;
564 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
565 stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
566 stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
567 stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
568 stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
569 stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
570
571 chan->next_sg++;
572
573 /* Clear interrupt status if it is there */
574 status = stm32_dma_irq_status(chan);
575 if (status)
576 stm32_dma_irq_clear(chan, status);
577
578 if (chan->desc->cyclic)
579 stm32_dma_configure_next_sg(chan);
580
581 stm32_dma_dump_reg(chan);
582
583 /* Start DMA */
584 reg->dma_scr |= STM32_DMA_SCR_EN;
585 stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
586
587 chan->busy = true;
588
589 dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
590}
591
592static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
593{
594 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
595 struct stm32_dma_sg_req *sg_req;
596 u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
597
598 id = chan->id;
599 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
600
601 if (dma_scr & STM32_DMA_SCR_DBM) {
602 if (chan->next_sg == chan->desc->num_sgs)
603 chan->next_sg = 0;
604
605 sg_req = &chan->desc->sg_req[chan->next_sg];
606
607 if (dma_scr & STM32_DMA_SCR_CT) {
608 dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
609 stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
610 dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
611 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
612 } else {
613 dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
614 stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
615 dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
616 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
617 }
618 }
619}
620
621static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
622{
623 if (chan->desc) {
624 if (chan->desc->cyclic) {
625 vchan_cyclic_callback(&chan->desc->vdesc);
626 chan->next_sg++;
627 stm32_dma_configure_next_sg(chan);
628 } else {
629 chan->busy = false;
630 if (chan->next_sg == chan->desc->num_sgs) {
631 vchan_cookie_complete(&chan->desc->vdesc);
632 chan->desc = NULL;
633 }
634 stm32_dma_start_transfer(chan);
635 }
636 }
637}
638
639static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
640{
641 struct stm32_dma_chan *chan = devid;
642 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
643 u32 status, scr, sfcr;
644
645 spin_lock(&chan->vchan.lock);
646
647 status = stm32_dma_irq_status(chan);
648 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
649 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
650
651 if (status & STM32_DMA_TCI) {
652 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
653 if (scr & STM32_DMA_SCR_TCIE)
654 stm32_dma_handle_chan_done(chan);
655 status &= ~STM32_DMA_TCI;
656 }
657 if (status & STM32_DMA_HTI) {
658 stm32_dma_irq_clear(chan, STM32_DMA_HTI);
659 status &= ~STM32_DMA_HTI;
660 }
661 if (status & STM32_DMA_FEI) {
662 stm32_dma_irq_clear(chan, STM32_DMA_FEI);
663 status &= ~STM32_DMA_FEI;
664 if (sfcr & STM32_DMA_SFCR_FEIE) {
665 if (!(scr & STM32_DMA_SCR_EN))
666 dev_err(chan2dev(chan), "FIFO Error\n");
667 else
668 dev_dbg(chan2dev(chan), "FIFO over/underrun\n");
669 }
670 }
671 if (status & STM32_DMA_DMEI) {
672 stm32_dma_irq_clear(chan, STM32_DMA_DMEI);
673 status &= ~STM32_DMA_DMEI;
674 if (sfcr & STM32_DMA_SCR_DMEIE)
675 dev_dbg(chan2dev(chan), "Direct mode overrun\n");
676 }
677 if (status) {
678 stm32_dma_irq_clear(chan, status);
679 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
680 if (!(scr & STM32_DMA_SCR_EN))
681 dev_err(chan2dev(chan), "chan disabled by HW\n");
682 }
683
684 spin_unlock(&chan->vchan.lock);
685
686 return IRQ_HANDLED;
687}
688
689static void stm32_dma_issue_pending(struct dma_chan *c)
690{
691 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
692 unsigned long flags;
693
694 spin_lock_irqsave(&chan->vchan.lock, flags);
695 if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
696 dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);
697 stm32_dma_start_transfer(chan);
698
699 }
700 spin_unlock_irqrestore(&chan->vchan.lock, flags);
701}
702
703static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
704 enum dma_transfer_direction direction,
705 enum dma_slave_buswidth *buswidth,
706 u32 buf_len)
707{
708 enum dma_slave_buswidth src_addr_width, dst_addr_width;
709 int src_bus_width, dst_bus_width;
710 int src_burst_size, dst_burst_size;
711 u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
712 u32 dma_scr, fifoth;
713
714 src_addr_width = chan->dma_sconfig.src_addr_width;
715 dst_addr_width = chan->dma_sconfig.dst_addr_width;
716 src_maxburst = chan->dma_sconfig.src_maxburst;
717 dst_maxburst = chan->dma_sconfig.dst_maxburst;
718 fifoth = chan->threshold;
719
720 switch (direction) {
721 case DMA_MEM_TO_DEV:
722 /* Set device data size */
723 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
724 if (dst_bus_width < 0)
725 return dst_bus_width;
726
727 /* Set device burst size */
728 dst_best_burst = stm32_dma_get_best_burst(buf_len,
729 dst_maxburst,
730 fifoth,
731 dst_addr_width);
732
733 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
734 if (dst_burst_size < 0)
735 return dst_burst_size;
736
737 /* Set memory data size */
738 src_addr_width = stm32_dma_get_max_width(buf_len, fifoth);
739 chan->mem_width = src_addr_width;
740 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
741 if (src_bus_width < 0)
742 return src_bus_width;
743
744 /* Set memory burst size */
745 src_maxburst = STM32_DMA_MAX_BURST;
746 src_best_burst = stm32_dma_get_best_burst(buf_len,
747 src_maxburst,
748 fifoth,
749 src_addr_width);
750 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
751 if (src_burst_size < 0)
752 return src_burst_size;
753
754 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
755 STM32_DMA_SCR_PSIZE(dst_bus_width) |
756 STM32_DMA_SCR_MSIZE(src_bus_width) |
757 STM32_DMA_SCR_PBURST(dst_burst_size) |
758 STM32_DMA_SCR_MBURST(src_burst_size);
759
760 /* Set FIFO threshold */
761 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
762 if (fifoth != STM32_DMA_FIFO_THRESHOLD_NONE)
763 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_FTH(fifoth);
764
765 /* Set peripheral address */
766 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
767 *buswidth = dst_addr_width;
768 break;
769
770 case DMA_DEV_TO_MEM:
771 /* Set device data size */
772 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
773 if (src_bus_width < 0)
774 return src_bus_width;
775
776 /* Set device burst size */
777 src_best_burst = stm32_dma_get_best_burst(buf_len,
778 src_maxburst,
779 fifoth,
780 src_addr_width);
781 chan->mem_burst = src_best_burst;
782 src_burst_size = stm32_dma_get_burst(chan, src_best_burst);
783 if (src_burst_size < 0)
784 return src_burst_size;
785
786 /* Set memory data size */
787 dst_addr_width = stm32_dma_get_max_width(buf_len, fifoth);
788 chan->mem_width = dst_addr_width;
789 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
790 if (dst_bus_width < 0)
791 return dst_bus_width;
792
793 /* Set memory burst size */
794 dst_maxburst = STM32_DMA_MAX_BURST;
795 dst_best_burst = stm32_dma_get_best_burst(buf_len,
796 dst_maxburst,
797 fifoth,
798 dst_addr_width);
799 chan->mem_burst = dst_best_burst;
800 dst_burst_size = stm32_dma_get_burst(chan, dst_best_burst);
801 if (dst_burst_size < 0)
802 return dst_burst_size;
803
804 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
805 STM32_DMA_SCR_PSIZE(src_bus_width) |
806 STM32_DMA_SCR_MSIZE(dst_bus_width) |
807 STM32_DMA_SCR_PBURST(src_burst_size) |
808 STM32_DMA_SCR_MBURST(dst_burst_size);
809
810 /* Set FIFO threshold */
811 chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_FTH_MASK;
812 if (fifoth != STM32_DMA_FIFO_THRESHOLD_NONE)
813 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_FTH(fifoth);
814
815 /* Set peripheral address */
816 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
817 *buswidth = chan->dma_sconfig.src_addr_width;
818 break;
819
820 default:
821 dev_err(chan2dev(chan), "Dma direction is not supported\n");
822 return -EINVAL;
823 }
824
825 stm32_dma_set_fifo_config(chan, src_best_burst, dst_best_burst);
826
827 /* Set DMA control register */
828 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
829 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
830 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
831 chan->chan_reg.dma_scr |= dma_scr;
832
833 return 0;
834}
835
836static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
837{
838 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
839}
840
841static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
842 struct dma_chan *c, struct scatterlist *sgl,
843 u32 sg_len, enum dma_transfer_direction direction,
844 unsigned long flags, void *context)
845{
846 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
847 struct stm32_dma_desc *desc;
848 struct scatterlist *sg;
849 enum dma_slave_buswidth buswidth;
850 u32 nb_data_items;
851 int i, ret;
852
853 if (!chan->config_init) {
854 dev_err(chan2dev(chan), "dma channel is not configured\n");
855 return NULL;
856 }
857
858 if (sg_len < 1) {
859 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
860 return NULL;
861 }
862
863 desc = kzalloc(struct_size(desc, sg_req, sg_len), GFP_NOWAIT);
864 if (!desc)
865 return NULL;
866
867 /* Set peripheral flow controller */
868 if (chan->dma_sconfig.device_fc)
869 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
870 else
871 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
872
873 for_each_sg(sgl, sg, sg_len, i) {
874 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth,
875 sg_dma_len(sg));
876 if (ret < 0)
877 goto err;
878
879 desc->sg_req[i].len = sg_dma_len(sg);
880
881 nb_data_items = desc->sg_req[i].len / buswidth;
882 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
883 dev_err(chan2dev(chan), "nb items not supported\n");
884 goto err;
885 }
886
887 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
888 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
889 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
890 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
891 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
892 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
893 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
894 }
895
896 desc->num_sgs = sg_len;
897 desc->cyclic = false;
898
899 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
900
901err:
902 kfree(desc);
903 return NULL;
904}
905
906static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
907 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
908 size_t period_len, enum dma_transfer_direction direction,
909 unsigned long flags)
910{
911 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
912 struct stm32_dma_desc *desc;
913 enum dma_slave_buswidth buswidth;
914 u32 num_periods, nb_data_items;
915 int i, ret;
916
917 if (!buf_len || !period_len) {
918 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
919 return NULL;
920 }
921
922 if (!chan->config_init) {
923 dev_err(chan2dev(chan), "dma channel is not configured\n");
924 return NULL;
925 }
926
927 if (buf_len % period_len) {
928 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
929 return NULL;
930 }
931
932 /*
933 * We allow to take more number of requests till DMA is
934 * not started. The driver will loop over all requests.
935 * Once DMA is started then new requests can be queued only after
936 * terminating the DMA.
937 */
938 if (chan->busy) {
939 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
940 return NULL;
941 }
942
943 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth, period_len);
944 if (ret < 0)
945 return NULL;
946
947 nb_data_items = period_len / buswidth;
948 if (nb_data_items > STM32_DMA_ALIGNED_MAX_DATA_ITEMS) {
949 dev_err(chan2dev(chan), "number of items not supported\n");
950 return NULL;
951 }
952
953 /* Enable Circular mode or double buffer mode */
954 if (buf_len == period_len)
955 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
956 else
957 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
958
959 /* Clear periph ctrl if client set it */
960 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
961
962 num_periods = buf_len / period_len;
963
964 desc = kzalloc(struct_size(desc, sg_req, num_periods), GFP_NOWAIT);
965 if (!desc)
966 return NULL;
967
968 for (i = 0; i < num_periods; i++) {
969 desc->sg_req[i].len = period_len;
970
971 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
972 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
973 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
974 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
975 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
976 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
977 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
978 buf_addr += period_len;
979 }
980
981 desc->num_sgs = num_periods;
982 desc->cyclic = true;
983
984 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
985}
986
987static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
988 struct dma_chan *c, dma_addr_t dest,
989 dma_addr_t src, size_t len, unsigned long flags)
990{
991 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
992 enum dma_slave_buswidth max_width;
993 struct stm32_dma_desc *desc;
994 size_t xfer_count, offset;
995 u32 num_sgs, best_burst, dma_burst, threshold;
996 int i;
997
998 num_sgs = DIV_ROUND_UP(len, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
999 desc = kzalloc(struct_size(desc, sg_req, num_sgs), GFP_NOWAIT);
1000 if (!desc)
1001 return NULL;
1002
1003 threshold = chan->threshold;
1004
1005 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
1006 xfer_count = min_t(size_t, len - offset,
1007 STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1008
1009 /* Compute best burst size */
1010 max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1011 best_burst = stm32_dma_get_best_burst(len, STM32_DMA_MAX_BURST,
1012 threshold, max_width);
1013 dma_burst = stm32_dma_get_burst(chan, best_burst);
1014
1015 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
1016 desc->sg_req[i].chan_reg.dma_scr =
1017 STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
1018 STM32_DMA_SCR_PBURST(dma_burst) |
1019 STM32_DMA_SCR_MBURST(dma_burst) |
1020 STM32_DMA_SCR_MINC |
1021 STM32_DMA_SCR_PINC |
1022 STM32_DMA_SCR_TCIE |
1023 STM32_DMA_SCR_TEIE;
1024 desc->sg_req[i].chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
1025 desc->sg_req[i].chan_reg.dma_sfcr |=
1026 STM32_DMA_SFCR_FTH(threshold);
1027 desc->sg_req[i].chan_reg.dma_spar = src + offset;
1028 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
1029 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
1030 desc->sg_req[i].len = xfer_count;
1031 }
1032
1033 desc->num_sgs = num_sgs;
1034 desc->cyclic = false;
1035
1036 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
1037}
1038
1039static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
1040{
1041 u32 dma_scr, width, ndtr;
1042 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1043
1044 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
1045 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
1046 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
1047
1048 return ndtr << width;
1049}
1050
1051/**
1052 * stm32_dma_is_current_sg - check that expected sg_req is currently transferred
1053 * @chan: dma channel
1054 *
1055 * This function called when IRQ are disable, checks that the hardware has not
1056 * switched on the next transfer in double buffer mode. The test is done by
1057 * comparing the next_sg memory address with the hardware related register
1058 * (based on CT bit value).
1059 *
1060 * Returns true if expected current transfer is still running or double
1061 * buffer mode is not activated.
1062 */
1063static bool stm32_dma_is_current_sg(struct stm32_dma_chan *chan)
1064{
1065 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1066 struct stm32_dma_sg_req *sg_req;
1067 u32 dma_scr, dma_smar, id;
1068
1069 id = chan->id;
1070 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
1071
1072 if (!(dma_scr & STM32_DMA_SCR_DBM))
1073 return true;
1074
1075 sg_req = &chan->desc->sg_req[chan->next_sg];
1076
1077 if (dma_scr & STM32_DMA_SCR_CT) {
1078 dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(id));
1079 return (dma_smar == sg_req->chan_reg.dma_sm0ar);
1080 }
1081
1082 dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(id));
1083
1084 return (dma_smar == sg_req->chan_reg.dma_sm1ar);
1085}
1086
1087static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
1088 struct stm32_dma_desc *desc,
1089 u32 next_sg)
1090{
1091 u32 modulo, burst_size;
1092 u32 residue;
1093 u32 n_sg = next_sg;
1094 struct stm32_dma_sg_req *sg_req = &chan->desc->sg_req[chan->next_sg];
1095 int i;
1096
1097 /*
1098 * Calculate the residue means compute the descriptors
1099 * information:
1100 * - the sg_req currently transferred
1101 * - the Hardware remaining position in this sg (NDTR bits field).
1102 *
1103 * A race condition may occur if DMA is running in cyclic or double
1104 * buffer mode, since the DMA register are automatically reloaded at end
1105 * of period transfer. The hardware may have switched to the next
1106 * transfer (CT bit updated) just before the position (SxNDTR reg) is
1107 * read.
1108 * In this case the SxNDTR reg could (or not) correspond to the new
1109 * transfer position, and not the expected one.
1110 * The strategy implemented in the stm32 driver is to:
1111 * - read the SxNDTR register
1112 * - crosscheck that hardware is still in current transfer.
1113 * In case of switch, we can assume that the DMA is at the beginning of
1114 * the next transfer. So we approximate the residue in consequence, by
1115 * pointing on the beginning of next transfer.
1116 *
1117 * This race condition doesn't apply for none cyclic mode, as double
1118 * buffer is not used. In such situation registers are updated by the
1119 * software.
1120 */
1121
1122 residue = stm32_dma_get_remaining_bytes(chan);
1123
1124 if (!stm32_dma_is_current_sg(chan)) {
1125 n_sg++;
1126 if (n_sg == chan->desc->num_sgs)
1127 n_sg = 0;
1128 residue = sg_req->len;
1129 }
1130
1131 /*
1132 * In cyclic mode, for the last period, residue = remaining bytes
1133 * from NDTR,
1134 * else for all other periods in cyclic mode, and in sg mode,
1135 * residue = remaining bytes from NDTR + remaining
1136 * periods/sg to be transferred
1137 */
1138 if (!chan->desc->cyclic || n_sg != 0)
1139 for (i = n_sg; i < desc->num_sgs; i++)
1140 residue += desc->sg_req[i].len;
1141
1142 if (!chan->mem_burst)
1143 return residue;
1144
1145 burst_size = chan->mem_burst * chan->mem_width;
1146 modulo = residue % burst_size;
1147 if (modulo)
1148 residue = residue - modulo + burst_size;
1149
1150 return residue;
1151}
1152
1153static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
1154 dma_cookie_t cookie,
1155 struct dma_tx_state *state)
1156{
1157 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1158 struct virt_dma_desc *vdesc;
1159 enum dma_status status;
1160 unsigned long flags;
1161 u32 residue = 0;
1162
1163 status = dma_cookie_status(c, cookie, state);
1164 if (status == DMA_COMPLETE || !state)
1165 return status;
1166
1167 spin_lock_irqsave(&chan->vchan.lock, flags);
1168 vdesc = vchan_find_desc(&chan->vchan, cookie);
1169 if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
1170 residue = stm32_dma_desc_residue(chan, chan->desc,
1171 chan->next_sg);
1172 else if (vdesc)
1173 residue = stm32_dma_desc_residue(chan,
1174 to_stm32_dma_desc(vdesc), 0);
1175 dma_set_residue(state, residue);
1176
1177 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1178
1179 return status;
1180}
1181
1182static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
1183{
1184 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1185 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1186 int ret;
1187
1188 chan->config_init = false;
1189
1190 ret = pm_runtime_get_sync(dmadev->ddev.dev);
1191 if (ret < 0)
1192 return ret;
1193
1194 ret = stm32_dma_disable_chan(chan);
1195 if (ret < 0)
1196 pm_runtime_put(dmadev->ddev.dev);
1197
1198 return ret;
1199}
1200
1201static void stm32_dma_free_chan_resources(struct dma_chan *c)
1202{
1203 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
1204 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
1205 unsigned long flags;
1206
1207 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
1208
1209 if (chan->busy) {
1210 spin_lock_irqsave(&chan->vchan.lock, flags);
1211 stm32_dma_stop(chan);
1212 chan->desc = NULL;
1213 spin_unlock_irqrestore(&chan->vchan.lock, flags);
1214 }
1215
1216 pm_runtime_put(dmadev->ddev.dev);
1217
1218 vchan_free_chan_resources(to_virt_chan(c));
1219}
1220
1221static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
1222{
1223 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
1224}
1225
1226static void stm32_dma_set_config(struct stm32_dma_chan *chan,
1227 struct stm32_dma_cfg *cfg)
1228{
1229 stm32_dma_clear_reg(&chan->chan_reg);
1230
1231 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
1232 chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
1233
1234 /* Enable Interrupts */
1235 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
1236
1237 chan->threshold = STM32_DMA_THRESHOLD_FTR_GET(cfg->features);
1238 if (STM32_DMA_DIRECT_MODE_GET(cfg->features))
1239 chan->threshold = STM32_DMA_FIFO_THRESHOLD_NONE;
1240}
1241
1242static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
1243 struct of_dma *ofdma)
1244{
1245 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
1246 struct device *dev = dmadev->ddev.dev;
1247 struct stm32_dma_cfg cfg;
1248 struct stm32_dma_chan *chan;
1249 struct dma_chan *c;
1250
1251 if (dma_spec->args_count < 4) {
1252 dev_err(dev, "Bad number of cells\n");
1253 return NULL;
1254 }
1255
1256 cfg.channel_id = dma_spec->args[0];
1257 cfg.request_line = dma_spec->args[1];
1258 cfg.stream_config = dma_spec->args[2];
1259 cfg.features = dma_spec->args[3];
1260
1261 if (cfg.channel_id >= STM32_DMA_MAX_CHANNELS ||
1262 cfg.request_line >= STM32_DMA_MAX_REQUEST_ID) {
1263 dev_err(dev, "Bad channel and/or request id\n");
1264 return NULL;
1265 }
1266
1267 chan = &dmadev->chan[cfg.channel_id];
1268
1269 c = dma_get_slave_channel(&chan->vchan.chan);
1270 if (!c) {
1271 dev_err(dev, "No more channels available\n");
1272 return NULL;
1273 }
1274
1275 stm32_dma_set_config(chan, &cfg);
1276
1277 return c;
1278}
1279
1280static const struct of_device_id stm32_dma_of_match[] = {
1281 { .compatible = "st,stm32-dma", },
1282 { /* sentinel */ },
1283};
1284MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1285
1286static int stm32_dma_probe(struct platform_device *pdev)
1287{
1288 struct stm32_dma_chan *chan;
1289 struct stm32_dma_device *dmadev;
1290 struct dma_device *dd;
1291 const struct of_device_id *match;
1292 struct resource *res;
1293 struct reset_control *rst;
1294 int i, ret;
1295
1296 match = of_match_device(stm32_dma_of_match, &pdev->dev);
1297 if (!match) {
1298 dev_err(&pdev->dev, "Error: No device match found\n");
1299 return -ENODEV;
1300 }
1301
1302 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1303 if (!dmadev)
1304 return -ENOMEM;
1305
1306 dd = &dmadev->ddev;
1307
1308 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1309 dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1310 if (IS_ERR(dmadev->base))
1311 return PTR_ERR(dmadev->base);
1312
1313 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1314 if (IS_ERR(dmadev->clk)) {
1315 ret = PTR_ERR(dmadev->clk);
1316 if (ret != -EPROBE_DEFER)
1317 dev_err(&pdev->dev, "Can't get clock\n");
1318 return ret;
1319 }
1320
1321 ret = clk_prepare_enable(dmadev->clk);
1322 if (ret < 0) {
1323 dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
1324 return ret;
1325 }
1326
1327 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1328 "st,mem2mem");
1329
1330 rst = devm_reset_control_get(&pdev->dev, NULL);
1331 if (IS_ERR(rst)) {
1332 ret = PTR_ERR(rst);
1333 if (ret == -EPROBE_DEFER)
1334 goto clk_free;
1335 } else {
1336 reset_control_assert(rst);
1337 udelay(2);
1338 reset_control_deassert(rst);
1339 }
1340
1341 dma_set_max_seg_size(&pdev->dev, STM32_DMA_ALIGNED_MAX_DATA_ITEMS);
1342
1343 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1344 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1345 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1346 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1347 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1348 dd->device_tx_status = stm32_dma_tx_status;
1349 dd->device_issue_pending = stm32_dma_issue_pending;
1350 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1351 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1352 dd->device_config = stm32_dma_slave_config;
1353 dd->device_terminate_all = stm32_dma_terminate_all;
1354 dd->device_synchronize = stm32_dma_synchronize;
1355 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1356 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1357 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1358 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1359 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1360 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1361 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1362 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1363 dd->copy_align = DMAENGINE_ALIGN_32_BYTES;
1364 dd->max_burst = STM32_DMA_MAX_BURST;
1365 dd->descriptor_reuse = true;
1366 dd->dev = &pdev->dev;
1367 INIT_LIST_HEAD(&dd->channels);
1368
1369 if (dmadev->mem2mem) {
1370 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1371 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1372 dd->directions |= BIT(DMA_MEM_TO_MEM);
1373 }
1374
1375 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1376 chan = &dmadev->chan[i];
1377 chan->id = i;
1378 chan->vchan.desc_free = stm32_dma_desc_free;
1379 vchan_init(&chan->vchan, dd);
1380 }
1381
1382 ret = dma_async_device_register(dd);
1383 if (ret)
1384 goto clk_free;
1385
1386 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1387 chan = &dmadev->chan[i];
1388 ret = platform_get_irq(pdev, i);
1389 if (ret < 0)
1390 goto err_unregister;
1391 chan->irq = ret;
1392
1393 ret = devm_request_irq(&pdev->dev, chan->irq,
1394 stm32_dma_chan_irq, 0,
1395 dev_name(chan2dev(chan)), chan);
1396 if (ret) {
1397 dev_err(&pdev->dev,
1398 "request_irq failed with err %d channel %d\n",
1399 ret, i);
1400 goto err_unregister;
1401 }
1402 }
1403
1404 ret = of_dma_controller_register(pdev->dev.of_node,
1405 stm32_dma_of_xlate, dmadev);
1406 if (ret < 0) {
1407 dev_err(&pdev->dev,
1408 "STM32 DMA DMA OF registration failed %d\n", ret);
1409 goto err_unregister;
1410 }
1411
1412 platform_set_drvdata(pdev, dmadev);
1413
1414 pm_runtime_set_active(&pdev->dev);
1415 pm_runtime_enable(&pdev->dev);
1416 pm_runtime_get_noresume(&pdev->dev);
1417 pm_runtime_put(&pdev->dev);
1418
1419 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1420
1421 return 0;
1422
1423err_unregister:
1424 dma_async_device_unregister(dd);
1425clk_free:
1426 clk_disable_unprepare(dmadev->clk);
1427
1428 return ret;
1429}
1430
1431#ifdef CONFIG_PM
1432static int stm32_dma_runtime_suspend(struct device *dev)
1433{
1434 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1435
1436 clk_disable_unprepare(dmadev->clk);
1437
1438 return 0;
1439}
1440
1441static int stm32_dma_runtime_resume(struct device *dev)
1442{
1443 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1444 int ret;
1445
1446 ret = clk_prepare_enable(dmadev->clk);
1447 if (ret) {
1448 dev_err(dev, "failed to prepare_enable clock\n");
1449 return ret;
1450 }
1451
1452 return 0;
1453}
1454#endif
1455
1456#ifdef CONFIG_PM_SLEEP
1457static int stm32_dma_suspend(struct device *dev)
1458{
1459 struct stm32_dma_device *dmadev = dev_get_drvdata(dev);
1460 int id, ret, scr;
1461
1462 ret = pm_runtime_get_sync(dev);
1463 if (ret < 0)
1464 return ret;
1465
1466 for (id = 0; id < STM32_DMA_MAX_CHANNELS; id++) {
1467 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
1468 if (scr & STM32_DMA_SCR_EN) {
1469 dev_warn(dev, "Suspend is prevented by Chan %i\n", id);
1470 return -EBUSY;
1471 }
1472 }
1473
1474 pm_runtime_put_sync(dev);
1475
1476 pm_runtime_force_suspend(dev);
1477
1478 return 0;
1479}
1480
1481static int stm32_dma_resume(struct device *dev)
1482{
1483 return pm_runtime_force_resume(dev);
1484}
1485#endif
1486
1487static const struct dev_pm_ops stm32_dma_pm_ops = {
1488 SET_SYSTEM_SLEEP_PM_OPS(stm32_dma_suspend, stm32_dma_resume)
1489 SET_RUNTIME_PM_OPS(stm32_dma_runtime_suspend,
1490 stm32_dma_runtime_resume, NULL)
1491};
1492
1493static struct platform_driver stm32_dma_driver = {
1494 .driver = {
1495 .name = "stm32-dma",
1496 .of_match_table = stm32_dma_of_match,
1497 .pm = &stm32_dma_pm_ops,
1498 },
1499 .probe = stm32_dma_probe,
1500};
1501
1502static int __init stm32_dma_init(void)
1503{
1504 return platform_driver_register(&stm32_dma_driver);
1505}
1506subsys_initcall(stm32_dma_init);
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
118enum stm32_dma_width {
119 STM32_DMA_BYTE,
120 STM32_DMA_HALF_WORD,
121 STM32_DMA_WORD,
122};
123
124enum 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
131struct stm32_dma_cfg {
132 u32 channel_id;
133 u32 request_line;
134 u32 stream_config;
135 u32 threshold;
136};
137
138struct 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
151struct stm32_dma_sg_req {
152 u32 len;
153 struct stm32_dma_chan_reg chan_reg;
154};
155
156struct 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
163struct 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
175struct 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
184static 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
190static 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
195static 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
200static struct device *chan2dev(struct stm32_dma_chan *chan)
201{
202 return &chan->vchan.chan.dev->device;
203}
204
205static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
206{
207 return readl_relaxed(dmadev->base + reg);
208}
209
210static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
211{
212 writel_relaxed(val, dmadev->base + reg);
213}
214
215static 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
221static 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
237static 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
255static 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
270static 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
282static 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
305static 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
325static 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
356static 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
386static 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
406static 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
424static 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
477static 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
508static 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
526static 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;
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
537 if ((status & STM32_DMA_TCI) && (scr & STM32_DMA_SCR_TCIE)) {
538 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
539 stm32_dma_handle_chan_done(chan);
540
541 } else {
542 stm32_dma_irq_clear(chan, status);
543 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
544 }
545
546 spin_unlock(&chan->vchan.lock);
547
548 return IRQ_HANDLED;
549}
550
551static void stm32_dma_issue_pending(struct dma_chan *c)
552{
553 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
554 unsigned long flags;
555 int ret;
556
557 spin_lock_irqsave(&chan->vchan.lock, flags);
558 if (!chan->busy) {
559 if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
560 ret = stm32_dma_start_transfer(chan);
561 if ((!ret) && (chan->desc->cyclic))
562 stm32_dma_configure_next_sg(chan);
563 }
564 }
565 spin_unlock_irqrestore(&chan->vchan.lock, flags);
566}
567
568static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
569 enum dma_transfer_direction direction,
570 enum dma_slave_buswidth *buswidth)
571{
572 enum dma_slave_buswidth src_addr_width, dst_addr_width;
573 int src_bus_width, dst_bus_width;
574 int src_burst_size, dst_burst_size;
575 u32 src_maxburst, dst_maxburst;
576 u32 dma_scr = 0;
577
578 src_addr_width = chan->dma_sconfig.src_addr_width;
579 dst_addr_width = chan->dma_sconfig.dst_addr_width;
580 src_maxburst = chan->dma_sconfig.src_maxburst;
581 dst_maxburst = chan->dma_sconfig.dst_maxburst;
582
583 switch (direction) {
584 case DMA_MEM_TO_DEV:
585 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
586 if (dst_bus_width < 0)
587 return dst_bus_width;
588
589 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
590 if (dst_burst_size < 0)
591 return dst_burst_size;
592
593 if (!src_addr_width)
594 src_addr_width = dst_addr_width;
595
596 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
597 if (src_bus_width < 0)
598 return src_bus_width;
599
600 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
601 if (src_burst_size < 0)
602 return src_burst_size;
603
604 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
605 STM32_DMA_SCR_PSIZE(dst_bus_width) |
606 STM32_DMA_SCR_MSIZE(src_bus_width) |
607 STM32_DMA_SCR_PBURST(dst_burst_size) |
608 STM32_DMA_SCR_MBURST(src_burst_size);
609
610 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
611 *buswidth = dst_addr_width;
612 break;
613
614 case DMA_DEV_TO_MEM:
615 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
616 if (src_bus_width < 0)
617 return src_bus_width;
618
619 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
620 if (src_burst_size < 0)
621 return src_burst_size;
622
623 if (!dst_addr_width)
624 dst_addr_width = src_addr_width;
625
626 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
627 if (dst_bus_width < 0)
628 return dst_bus_width;
629
630 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
631 if (dst_burst_size < 0)
632 return dst_burst_size;
633
634 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
635 STM32_DMA_SCR_PSIZE(src_bus_width) |
636 STM32_DMA_SCR_MSIZE(dst_bus_width) |
637 STM32_DMA_SCR_PBURST(src_burst_size) |
638 STM32_DMA_SCR_MBURST(dst_burst_size);
639
640 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
641 *buswidth = chan->dma_sconfig.src_addr_width;
642 break;
643
644 default:
645 dev_err(chan2dev(chan), "Dma direction is not supported\n");
646 return -EINVAL;
647 }
648
649 stm32_dma_set_fifo_config(chan, src_maxburst, dst_maxburst);
650
651 chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
652 STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
653 STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
654 chan->chan_reg.dma_scr |= dma_scr;
655
656 return 0;
657}
658
659static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
660{
661 memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
662}
663
664static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
665 struct dma_chan *c, struct scatterlist *sgl,
666 u32 sg_len, enum dma_transfer_direction direction,
667 unsigned long flags, void *context)
668{
669 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
670 struct stm32_dma_desc *desc;
671 struct scatterlist *sg;
672 enum dma_slave_buswidth buswidth;
673 u32 nb_data_items;
674 int i, ret;
675
676 if (!chan->config_init) {
677 dev_err(chan2dev(chan), "dma channel is not configured\n");
678 return NULL;
679 }
680
681 if (sg_len < 1) {
682 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
683 return NULL;
684 }
685
686 desc = stm32_dma_alloc_desc(sg_len);
687 if (!desc)
688 return NULL;
689
690 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
691 if (ret < 0)
692 goto err;
693
694 /* Set peripheral flow controller */
695 if (chan->dma_sconfig.device_fc)
696 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
697 else
698 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
699
700 for_each_sg(sgl, sg, sg_len, i) {
701 desc->sg_req[i].len = sg_dma_len(sg);
702
703 nb_data_items = desc->sg_req[i].len / buswidth;
704 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
705 dev_err(chan2dev(chan), "nb items not supported\n");
706 goto err;
707 }
708
709 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
710 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
711 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
712 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
713 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
714 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
715 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
716 }
717
718 desc->num_sgs = sg_len;
719 desc->cyclic = false;
720
721 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
722
723err:
724 kfree(desc);
725 return NULL;
726}
727
728static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
729 struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
730 size_t period_len, enum dma_transfer_direction direction,
731 unsigned long flags)
732{
733 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
734 struct stm32_dma_desc *desc;
735 enum dma_slave_buswidth buswidth;
736 u32 num_periods, nb_data_items;
737 int i, ret;
738
739 if (!buf_len || !period_len) {
740 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
741 return NULL;
742 }
743
744 if (!chan->config_init) {
745 dev_err(chan2dev(chan), "dma channel is not configured\n");
746 return NULL;
747 }
748
749 if (buf_len % period_len) {
750 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
751 return NULL;
752 }
753
754 /*
755 * We allow to take more number of requests till DMA is
756 * not started. The driver will loop over all requests.
757 * Once DMA is started then new requests can be queued only after
758 * terminating the DMA.
759 */
760 if (chan->busy) {
761 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
762 return NULL;
763 }
764
765 ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
766 if (ret < 0)
767 return NULL;
768
769 nb_data_items = period_len / buswidth;
770 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
771 dev_err(chan2dev(chan), "number of items not supported\n");
772 return NULL;
773 }
774
775 /* Enable Circular mode or double buffer mode */
776 if (buf_len == period_len)
777 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
778 else
779 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
780
781 /* Clear periph ctrl if client set it */
782 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
783
784 num_periods = buf_len / period_len;
785
786 desc = stm32_dma_alloc_desc(num_periods);
787 if (!desc)
788 return NULL;
789
790 for (i = 0; i < num_periods; i++) {
791 desc->sg_req[i].len = period_len;
792
793 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
794 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
795 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
796 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
797 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
798 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
799 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
800 buf_addr += period_len;
801 }
802
803 desc->num_sgs = num_periods;
804 desc->cyclic = true;
805
806 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
807}
808
809static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
810 struct dma_chan *c, dma_addr_t dest,
811 dma_addr_t src, size_t len, unsigned long flags)
812{
813 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
814 u32 num_sgs;
815 struct stm32_dma_desc *desc;
816 size_t xfer_count, offset;
817 int i;
818
819 num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS);
820 desc = stm32_dma_alloc_desc(num_sgs);
821 if (!desc)
822 return NULL;
823
824 for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
825 xfer_count = min_t(size_t, len - offset,
826 STM32_DMA_MAX_DATA_ITEMS);
827
828 desc->sg_req[i].len = xfer_count;
829
830 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
831 desc->sg_req[i].chan_reg.dma_scr =
832 STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
833 STM32_DMA_SCR_MINC |
834 STM32_DMA_SCR_PINC |
835 STM32_DMA_SCR_TCIE |
836 STM32_DMA_SCR_TEIE;
837 desc->sg_req[i].chan_reg.dma_sfcr = STM32_DMA_SFCR_DMDIS |
838 STM32_DMA_SFCR_FTH(STM32_DMA_FIFO_THRESHOLD_FULL) |
839 STM32_DMA_SFCR_FEIE;
840 desc->sg_req[i].chan_reg.dma_spar = src + offset;
841 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
842 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
843 }
844
845 desc->num_sgs = num_sgs;
846 desc->cyclic = false;
847
848 return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
849}
850
851static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
852 struct stm32_dma_desc *desc,
853 u32 next_sg)
854{
855 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
856 u32 dma_scr, width, residue, count;
857 int i;
858
859 residue = 0;
860
861 for (i = next_sg; i < desc->num_sgs; i++)
862 residue += desc->sg_req[i].len;
863
864 if (next_sg != 0) {
865 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
866 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
867 count = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
868
869 residue += count << width;
870 }
871
872 return residue;
873}
874
875static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
876 dma_cookie_t cookie,
877 struct dma_tx_state *state)
878{
879 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
880 struct virt_dma_desc *vdesc;
881 enum dma_status status;
882 unsigned long flags;
883 u32 residue = 0;
884
885 status = dma_cookie_status(c, cookie, state);
886 if ((status == DMA_COMPLETE) || (!state))
887 return status;
888
889 spin_lock_irqsave(&chan->vchan.lock, flags);
890 vdesc = vchan_find_desc(&chan->vchan, cookie);
891 if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
892 residue = stm32_dma_desc_residue(chan, chan->desc,
893 chan->next_sg);
894 else if (vdesc)
895 residue = stm32_dma_desc_residue(chan,
896 to_stm32_dma_desc(vdesc), 0);
897 dma_set_residue(state, residue);
898
899 spin_unlock_irqrestore(&chan->vchan.lock, flags);
900
901 return status;
902}
903
904static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
905{
906 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
907 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
908 int ret;
909
910 chan->config_init = false;
911 ret = clk_prepare_enable(dmadev->clk);
912 if (ret < 0) {
913 dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
914 return ret;
915 }
916
917 ret = stm32_dma_disable_chan(chan);
918 if (ret < 0)
919 clk_disable_unprepare(dmadev->clk);
920
921 return ret;
922}
923
924static void stm32_dma_free_chan_resources(struct dma_chan *c)
925{
926 struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
927 struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
928 unsigned long flags;
929
930 dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
931
932 if (chan->busy) {
933 spin_lock_irqsave(&chan->vchan.lock, flags);
934 stm32_dma_stop(chan);
935 chan->desc = NULL;
936 spin_unlock_irqrestore(&chan->vchan.lock, flags);
937 }
938
939 clk_disable_unprepare(dmadev->clk);
940
941 vchan_free_chan_resources(to_virt_chan(c));
942}
943
944static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
945{
946 kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
947}
948
949static void stm32_dma_set_config(struct stm32_dma_chan *chan,
950 struct stm32_dma_cfg *cfg)
951{
952 stm32_dma_clear_reg(&chan->chan_reg);
953
954 chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
955 chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
956
957 /* Enable Interrupts */
958 chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
959
960 chan->chan_reg.dma_sfcr = cfg->threshold & STM32_DMA_SFCR_FTH_MASK;
961}
962
963static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
964 struct of_dma *ofdma)
965{
966 struct stm32_dma_device *dmadev = ofdma->of_dma_data;
967 struct stm32_dma_cfg cfg;
968 struct stm32_dma_chan *chan;
969 struct dma_chan *c;
970
971 if (dma_spec->args_count < 4)
972 return NULL;
973
974 cfg.channel_id = dma_spec->args[0];
975 cfg.request_line = dma_spec->args[1];
976 cfg.stream_config = dma_spec->args[2];
977 cfg.threshold = dma_spec->args[3];
978
979 if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >=
980 STM32_DMA_MAX_REQUEST_ID))
981 return NULL;
982
983 chan = &dmadev->chan[cfg.channel_id];
984
985 c = dma_get_slave_channel(&chan->vchan.chan);
986 if (c)
987 stm32_dma_set_config(chan, &cfg);
988
989 return c;
990}
991
992static const struct of_device_id stm32_dma_of_match[] = {
993 { .compatible = "st,stm32-dma", },
994 { /* sentinel */ },
995};
996MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
997
998static int stm32_dma_probe(struct platform_device *pdev)
999{
1000 struct stm32_dma_chan *chan;
1001 struct stm32_dma_device *dmadev;
1002 struct dma_device *dd;
1003 const struct of_device_id *match;
1004 struct resource *res;
1005 int i, ret;
1006
1007 match = of_match_device(stm32_dma_of_match, &pdev->dev);
1008 if (!match) {
1009 dev_err(&pdev->dev, "Error: No device match found\n");
1010 return -ENODEV;
1011 }
1012
1013 dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1014 if (!dmadev)
1015 return -ENOMEM;
1016
1017 dd = &dmadev->ddev;
1018
1019 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1020 dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1021 if (IS_ERR(dmadev->base))
1022 return PTR_ERR(dmadev->base);
1023
1024 dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1025 if (IS_ERR(dmadev->clk)) {
1026 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1027 return PTR_ERR(dmadev->clk);
1028 }
1029
1030 dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1031 "st,mem2mem");
1032
1033 dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
1034 if (!IS_ERR(dmadev->rst)) {
1035 reset_control_assert(dmadev->rst);
1036 udelay(2);
1037 reset_control_deassert(dmadev->rst);
1038 }
1039
1040 dma_cap_set(DMA_SLAVE, dd->cap_mask);
1041 dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1042 dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1043 dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1044 dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1045 dd->device_tx_status = stm32_dma_tx_status;
1046 dd->device_issue_pending = stm32_dma_issue_pending;
1047 dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1048 dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1049 dd->device_config = stm32_dma_slave_config;
1050 dd->device_terminate_all = stm32_dma_terminate_all;
1051 dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1052 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1053 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1054 dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1055 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1056 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1057 dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1058 dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1059 dd->dev = &pdev->dev;
1060 INIT_LIST_HEAD(&dd->channels);
1061
1062 if (dmadev->mem2mem) {
1063 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1064 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1065 dd->directions |= BIT(DMA_MEM_TO_MEM);
1066 }
1067
1068 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1069 chan = &dmadev->chan[i];
1070 chan->id = i;
1071 chan->vchan.desc_free = stm32_dma_desc_free;
1072 vchan_init(&chan->vchan, dd);
1073 }
1074
1075 ret = dma_async_device_register(dd);
1076 if (ret)
1077 return ret;
1078
1079 for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1080 chan = &dmadev->chan[i];
1081 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1082 if (!res) {
1083 ret = -EINVAL;
1084 dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1085 goto err_unregister;
1086 }
1087 chan->irq = res->start;
1088 ret = devm_request_irq(&pdev->dev, chan->irq,
1089 stm32_dma_chan_irq, 0,
1090 dev_name(chan2dev(chan)), chan);
1091 if (ret) {
1092 dev_err(&pdev->dev,
1093 "request_irq failed with err %d channel %d\n",
1094 ret, i);
1095 goto err_unregister;
1096 }
1097 }
1098
1099 ret = of_dma_controller_register(pdev->dev.of_node,
1100 stm32_dma_of_xlate, dmadev);
1101 if (ret < 0) {
1102 dev_err(&pdev->dev,
1103 "STM32 DMA DMA OF registration failed %d\n", ret);
1104 goto err_unregister;
1105 }
1106
1107 platform_set_drvdata(pdev, dmadev);
1108
1109 dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1110
1111 return 0;
1112
1113err_unregister:
1114 dma_async_device_unregister(dd);
1115
1116 return ret;
1117}
1118
1119static struct platform_driver stm32_dma_driver = {
1120 .driver = {
1121 .name = "stm32-dma",
1122 .of_match_table = stm32_dma_of_match,
1123 },
1124};
1125
1126static int __init stm32_dma_init(void)
1127{
1128 return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
1129}
1130subsys_initcall(stm32_dma_init);