GNU Linux-libre 4.9.328-gnu1
[releases.git] / drivers / dma / stm32-dma.c
1 /*
2  * Driver for STM32 DMA controller
3  *
4  * Inspired by dma-jz4740.c and tegra20-apb-dma.c
5  *
6  * Copyright (C) M'boumba Cedric Madianga 2015
7  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
8  *
9  * License terms:  GNU General Public License (GPL), version 2
10  */
11
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/dmaengine.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/jiffies.h>
19 #include <linux/list.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/of_device.h>
23 #include <linux/of_dma.h>
24 #include <linux/platform_device.h>
25 #include <linux/reset.h>
26 #include <linux/sched.h>
27 #include <linux/slab.h>
28
29 #include "virt-dma.h"
30
31 #define STM32_DMA_LISR                  0x0000 /* DMA Low Int Status Reg */
32 #define STM32_DMA_HISR                  0x0004 /* DMA High Int Status Reg */
33 #define STM32_DMA_LIFCR                 0x0008 /* DMA Low Int Flag Clear Reg */
34 #define STM32_DMA_HIFCR                 0x000c /* DMA High Int Flag Clear Reg */
35 #define STM32_DMA_TCI                   BIT(5) /* Transfer Complete Interrupt */
36 #define STM32_DMA_TEI                   BIT(3) /* Transfer Error Interrupt */
37 #define STM32_DMA_DMEI                  BIT(2) /* Direct Mode Error Interrupt */
38 #define STM32_DMA_FEI                   BIT(0) /* FIFO Error Interrupt */
39
40 /* DMA Stream x Configuration Register */
41 #define STM32_DMA_SCR(x)                (0x0010 + 0x18 * (x)) /* x = 0..7 */
42 #define STM32_DMA_SCR_REQ(n)            ((n & 0x7) << 25)
43 #define STM32_DMA_SCR_MBURST_MASK       GENMASK(24, 23)
44 #define STM32_DMA_SCR_MBURST(n)         ((n & 0x3) << 23)
45 #define STM32_DMA_SCR_PBURST_MASK       GENMASK(22, 21)
46 #define STM32_DMA_SCR_PBURST(n)         ((n & 0x3) << 21)
47 #define STM32_DMA_SCR_PL_MASK           GENMASK(17, 16)
48 #define STM32_DMA_SCR_PL(n)             ((n & 0x3) << 16)
49 #define STM32_DMA_SCR_MSIZE_MASK        GENMASK(14, 13)
50 #define STM32_DMA_SCR_MSIZE(n)          ((n & 0x3) << 13)
51 #define STM32_DMA_SCR_PSIZE_MASK        GENMASK(12, 11)
52 #define STM32_DMA_SCR_PSIZE(n)          ((n & 0x3) << 11)
53 #define STM32_DMA_SCR_PSIZE_GET(n)      ((n & STM32_DMA_SCR_PSIZE_MASK) >> 11)
54 #define STM32_DMA_SCR_DIR_MASK          GENMASK(7, 6)
55 #define STM32_DMA_SCR_DIR(n)            ((n & 0x3) << 6)
56 #define STM32_DMA_SCR_CT                BIT(19) /* Target in double buffer */
57 #define STM32_DMA_SCR_DBM               BIT(18) /* Double Buffer Mode */
58 #define STM32_DMA_SCR_PINCOS            BIT(15) /* Peripheral inc offset size */
59 #define STM32_DMA_SCR_MINC              BIT(10) /* Memory increment mode */
60 #define STM32_DMA_SCR_PINC              BIT(9) /* Peripheral increment mode */
61 #define STM32_DMA_SCR_CIRC              BIT(8) /* Circular mode */
62 #define STM32_DMA_SCR_PFCTRL            BIT(5) /* Peripheral Flow Controller */
63 #define STM32_DMA_SCR_TCIE              BIT(4) /* Transfer Cplete Int Enable*/
64 #define STM32_DMA_SCR_TEIE              BIT(2) /* Transfer Error Int Enable */
65 #define STM32_DMA_SCR_DMEIE             BIT(1) /* Direct Mode Err Int Enable */
66 #define STM32_DMA_SCR_EN                BIT(0) /* Stream Enable */
67 #define STM32_DMA_SCR_CFG_MASK          (STM32_DMA_SCR_PINC \
68                                         | STM32_DMA_SCR_MINC \
69                                         | STM32_DMA_SCR_PINCOS \
70                                         | STM32_DMA_SCR_PL_MASK)
71 #define STM32_DMA_SCR_IRQ_MASK          (STM32_DMA_SCR_TCIE \
72                                         | STM32_DMA_SCR_TEIE \
73                                         | STM32_DMA_SCR_DMEIE)
74
75 /* DMA Stream x number of data register */
76 #define STM32_DMA_SNDTR(x)              (0x0014 + 0x18 * (x))
77
78 /* DMA stream peripheral address register */
79 #define STM32_DMA_SPAR(x)               (0x0018 + 0x18 * (x))
80
81 /* DMA stream x memory 0 address register */
82 #define STM32_DMA_SM0AR(x)              (0x001c + 0x18 * (x))
83
84 /* DMA stream x memory 1 address register */
85 #define STM32_DMA_SM1AR(x)              (0x0020 + 0x18 * (x))
86
87 /* DMA stream x FIFO control register */
88 #define STM32_DMA_SFCR(x)               (0x0024 + 0x18 * (x))
89 #define STM32_DMA_SFCR_FTH_MASK         GENMASK(1, 0)
90 #define STM32_DMA_SFCR_FTH(n)           (n & STM32_DMA_SFCR_FTH_MASK)
91 #define STM32_DMA_SFCR_FEIE             BIT(7) /* FIFO error interrupt enable */
92 #define STM32_DMA_SFCR_DMDIS            BIT(2) /* Direct mode disable */
93 #define STM32_DMA_SFCR_MASK             (STM32_DMA_SFCR_FEIE \
94                                         | STM32_DMA_SFCR_DMDIS)
95
96 /* DMA direction */
97 #define STM32_DMA_DEV_TO_MEM            0x00
98 #define STM32_DMA_MEM_TO_DEV            0x01
99 #define STM32_DMA_MEM_TO_MEM            0x02
100
101 /* DMA priority level */
102 #define STM32_DMA_PRIORITY_LOW          0x00
103 #define STM32_DMA_PRIORITY_MEDIUM       0x01
104 #define STM32_DMA_PRIORITY_HIGH         0x02
105 #define STM32_DMA_PRIORITY_VERY_HIGH    0x03
106
107 /* DMA FIFO threshold selection */
108 #define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL           0x00
109 #define STM32_DMA_FIFO_THRESHOLD_HALFFULL               0x01
110 #define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL          0x02
111 #define STM32_DMA_FIFO_THRESHOLD_FULL                   0x03
112
113 #define STM32_DMA_MAX_DATA_ITEMS        0xffff
114 #define STM32_DMA_MAX_CHANNELS          0x08
115 #define STM32_DMA_MAX_REQUEST_ID        0x08
116 #define STM32_DMA_MAX_DATA_PARAM        0x03
117
118 enum stm32_dma_width {
119         STM32_DMA_BYTE,
120         STM32_DMA_HALF_WORD,
121         STM32_DMA_WORD,
122 };
123
124 enum stm32_dma_burst_size {
125         STM32_DMA_BURST_SINGLE,
126         STM32_DMA_BURST_INCR4,
127         STM32_DMA_BURST_INCR8,
128         STM32_DMA_BURST_INCR16,
129 };
130
131 struct stm32_dma_cfg {
132         u32 channel_id;
133         u32 request_line;
134         u32 stream_config;
135         u32 threshold;
136 };
137
138 struct stm32_dma_chan_reg {
139         u32 dma_lisr;
140         u32 dma_hisr;
141         u32 dma_lifcr;
142         u32 dma_hifcr;
143         u32 dma_scr;
144         u32 dma_sndtr;
145         u32 dma_spar;
146         u32 dma_sm0ar;
147         u32 dma_sm1ar;
148         u32 dma_sfcr;
149 };
150
151 struct stm32_dma_sg_req {
152         u32 len;
153         struct stm32_dma_chan_reg chan_reg;
154 };
155
156 struct stm32_dma_desc {
157         struct virt_dma_desc vdesc;
158         bool cyclic;
159         u32 num_sgs;
160         struct stm32_dma_sg_req sg_req[];
161 };
162
163 struct stm32_dma_chan {
164         struct virt_dma_chan vchan;
165         bool config_init;
166         bool busy;
167         u32 id;
168         u32 irq;
169         struct stm32_dma_desc *desc;
170         u32 next_sg;
171         struct dma_slave_config dma_sconfig;
172         struct stm32_dma_chan_reg chan_reg;
173 };
174
175 struct stm32_dma_device {
176         struct dma_device ddev;
177         void __iomem *base;
178         struct clk *clk;
179         struct reset_control *rst;
180         bool mem2mem;
181         struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS];
182 };
183
184 static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan)
185 {
186         return container_of(chan->vchan.chan.device, struct stm32_dma_device,
187                             ddev);
188 }
189
190 static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c)
191 {
192         return container_of(c, struct stm32_dma_chan, vchan.chan);
193 }
194
195 static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc)
196 {
197         return container_of(vdesc, struct stm32_dma_desc, vdesc);
198 }
199
200 static struct device *chan2dev(struct stm32_dma_chan *chan)
201 {
202         return &chan->vchan.chan.dev->device;
203 }
204
205 static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg)
206 {
207         return readl_relaxed(dmadev->base + reg);
208 }
209
210 static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val)
211 {
212         writel_relaxed(val, dmadev->base + reg);
213 }
214
215 static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs)
216 {
217         return kzalloc(sizeof(struct stm32_dma_desc) +
218                        sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT);
219 }
220
221 static int stm32_dma_get_width(struct stm32_dma_chan *chan,
222                                enum dma_slave_buswidth width)
223 {
224         switch (width) {
225         case DMA_SLAVE_BUSWIDTH_1_BYTE:
226                 return STM32_DMA_BYTE;
227         case DMA_SLAVE_BUSWIDTH_2_BYTES:
228                 return STM32_DMA_HALF_WORD;
229         case DMA_SLAVE_BUSWIDTH_4_BYTES:
230                 return STM32_DMA_WORD;
231         default:
232                 dev_err(chan2dev(chan), "Dma bus width not supported\n");
233                 return -EINVAL;
234         }
235 }
236
237 static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst)
238 {
239         switch (maxburst) {
240         case 0:
241         case 1:
242                 return STM32_DMA_BURST_SINGLE;
243         case 4:
244                 return STM32_DMA_BURST_INCR4;
245         case 8:
246                 return STM32_DMA_BURST_INCR8;
247         case 16:
248                 return STM32_DMA_BURST_INCR16;
249         default:
250                 dev_err(chan2dev(chan), "Dma burst size not supported\n");
251                 return -EINVAL;
252         }
253 }
254
255 static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan,
256                                       u32 src_maxburst, u32 dst_maxburst)
257 {
258         chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK;
259         chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE;
260
261         if ((!src_maxburst) && (!dst_maxburst)) {
262                 /* Using direct mode */
263                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE;
264         } else {
265                 /* Using FIFO mode */
266                 chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK;
267         }
268 }
269
270 static int stm32_dma_slave_config(struct dma_chan *c,
271                                   struct dma_slave_config *config)
272 {
273         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
274
275         memcpy(&chan->dma_sconfig, config, sizeof(*config));
276
277         chan->config_init = true;
278
279         return 0;
280 }
281
282 static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan)
283 {
284         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
285         u32 flags, dma_isr;
286
287         /*
288          * Read "flags" from DMA_xISR register corresponding to the selected
289          * DMA channel at the correct bit offset inside that register.
290          *
291          * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
292          * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
293          */
294
295         if (chan->id & 4)
296                 dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR);
297         else
298                 dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR);
299
300         flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
301
302         return flags;
303 }
304
305 static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags)
306 {
307         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
308         u32 dma_ifcr;
309
310         /*
311          * Write "flags" to the DMA_xIFCR register corresponding to the selected
312          * DMA channel at the correct bit offset inside that register.
313          *
314          * If (ch % 4) is 2 or 3, left shift the mask by 16 bits.
315          * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits.
316          */
317         dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6));
318
319         if (chan->id & 4)
320                 stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr);
321         else
322                 stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr);
323 }
324
325 static int stm32_dma_disable_chan(struct stm32_dma_chan *chan)
326 {
327         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
328         unsigned long timeout = jiffies + msecs_to_jiffies(5000);
329         u32 dma_scr, id;
330
331         id = chan->id;
332         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
333
334         if (dma_scr & STM32_DMA_SCR_EN) {
335                 dma_scr &= ~STM32_DMA_SCR_EN;
336                 stm32_dma_write(dmadev, STM32_DMA_SCR(id), dma_scr);
337
338                 do {
339                         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
340                         dma_scr &= STM32_DMA_SCR_EN;
341                         if (!dma_scr)
342                                 break;
343
344                         if (time_after_eq(jiffies, timeout)) {
345                                 dev_err(chan2dev(chan), "%s: timeout!\n",
346                                         __func__);
347                                 return -EBUSY;
348                         }
349                         cond_resched();
350                 } while (1);
351         }
352
353         return 0;
354 }
355
356 static void stm32_dma_stop(struct stm32_dma_chan *chan)
357 {
358         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
359         u32 dma_scr, dma_sfcr, status;
360         int ret;
361
362         /* Disable interrupts */
363         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
364         dma_scr &= ~STM32_DMA_SCR_IRQ_MASK;
365         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr);
366         dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
367         dma_sfcr &= ~STM32_DMA_SFCR_FEIE;
368         stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr);
369
370         /* Disable DMA */
371         ret = stm32_dma_disable_chan(chan);
372         if (ret < 0)
373                 return;
374
375         /* Clear interrupt status if it is there */
376         status = stm32_dma_irq_status(chan);
377         if (status) {
378                 dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
379                         __func__, status);
380                 stm32_dma_irq_clear(chan, status);
381         }
382
383         chan->busy = false;
384 }
385
386 static int stm32_dma_terminate_all(struct dma_chan *c)
387 {
388         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
389         unsigned long flags;
390         LIST_HEAD(head);
391
392         spin_lock_irqsave(&chan->vchan.lock, flags);
393
394         if (chan->busy) {
395                 stm32_dma_stop(chan);
396                 chan->desc = NULL;
397         }
398
399         vchan_get_all_descriptors(&chan->vchan, &head);
400         spin_unlock_irqrestore(&chan->vchan.lock, flags);
401         vchan_dma_desc_free_list(&chan->vchan, &head);
402
403         return 0;
404 }
405
406 static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
407 {
408         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
409         u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
410         u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
411         u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id));
412         u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id));
413         u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
414         u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
415
416         dev_dbg(chan2dev(chan), "SCR:   0x%08x\n", scr);
417         dev_dbg(chan2dev(chan), "NDTR:  0x%08x\n", ndtr);
418         dev_dbg(chan2dev(chan), "SPAR:  0x%08x\n", spar);
419         dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar);
420         dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar);
421         dev_dbg(chan2dev(chan), "SFCR:  0x%08x\n", sfcr);
422 }
423
424 static int stm32_dma_start_transfer(struct stm32_dma_chan *chan)
425 {
426         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
427         struct virt_dma_desc *vdesc;
428         struct stm32_dma_sg_req *sg_req;
429         struct stm32_dma_chan_reg *reg;
430         u32 status;
431         int ret;
432
433         ret = stm32_dma_disable_chan(chan);
434         if (ret < 0)
435                 return ret;
436
437         if (!chan->desc) {
438                 vdesc = vchan_next_desc(&chan->vchan);
439                 if (!vdesc)
440                         return -EPERM;
441
442                 chan->desc = to_stm32_dma_desc(vdesc);
443                 chan->next_sg = 0;
444         }
445
446         if (chan->next_sg == chan->desc->num_sgs)
447                 chan->next_sg = 0;
448
449         sg_req = &chan->desc->sg_req[chan->next_sg];
450         reg = &sg_req->chan_reg;
451
452         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
453         stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar);
454         stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar);
455         stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr);
456         stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
457         stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr);
458
459         chan->next_sg++;
460
461         /* Clear interrupt status if it is there */
462         status = stm32_dma_irq_status(chan);
463         if (status)
464                 stm32_dma_irq_clear(chan, status);
465
466         stm32_dma_dump_reg(chan);
467
468         /* Start DMA */
469         reg->dma_scr |= STM32_DMA_SCR_EN;
470         stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr);
471
472         chan->busy = true;
473
474         return 0;
475 }
476
477 static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
478 {
479         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
480         struct stm32_dma_sg_req *sg_req;
481         u32 dma_scr, dma_sm0ar, dma_sm1ar, id;
482
483         id = chan->id;
484         dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id));
485
486         if (dma_scr & STM32_DMA_SCR_DBM) {
487                 if (chan->next_sg == chan->desc->num_sgs)
488                         chan->next_sg = 0;
489
490                 sg_req = &chan->desc->sg_req[chan->next_sg];
491
492                 if (dma_scr & STM32_DMA_SCR_CT) {
493                         dma_sm0ar = sg_req->chan_reg.dma_sm0ar;
494                         stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar);
495                         dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n",
496                                 stm32_dma_read(dmadev, STM32_DMA_SM0AR(id)));
497                 } else {
498                         dma_sm1ar = sg_req->chan_reg.dma_sm1ar;
499                         stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
500                         dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
501                                 stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
502                 }
503
504                 chan->next_sg++;
505         }
506 }
507
508 static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
509 {
510         if (chan->desc) {
511                 if (chan->desc->cyclic) {
512                         vchan_cyclic_callback(&chan->desc->vdesc);
513                         stm32_dma_configure_next_sg(chan);
514                 } else {
515                         chan->busy = false;
516                         if (chan->next_sg == chan->desc->num_sgs) {
517                                 list_del(&chan->desc->vdesc.node);
518                                 vchan_cookie_complete(&chan->desc->vdesc);
519                                 chan->desc = NULL;
520                         }
521                         stm32_dma_start_transfer(chan);
522                 }
523         }
524 }
525
526 static irqreturn_t stm32_dma_chan_irq(int irq, void *devid)
527 {
528         struct stm32_dma_chan *chan = devid;
529         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
530         u32 status, scr, sfcr;
531
532         spin_lock(&chan->vchan.lock);
533
534         status = stm32_dma_irq_status(chan);
535         scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
536         sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id));
537
538         if ((status & STM32_DMA_TCI) && (scr & STM32_DMA_SCR_TCIE)) {
539                 stm32_dma_irq_clear(chan, STM32_DMA_TCI);
540                 stm32_dma_handle_chan_done(chan);
541
542         } else {
543                 stm32_dma_irq_clear(chan, status);
544                 dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
545         }
546
547         spin_unlock(&chan->vchan.lock);
548
549         return IRQ_HANDLED;
550 }
551
552 static void stm32_dma_issue_pending(struct dma_chan *c)
553 {
554         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
555         unsigned long flags;
556         int ret;
557
558         spin_lock_irqsave(&chan->vchan.lock, flags);
559         if (!chan->busy) {
560                 if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
561                         ret = stm32_dma_start_transfer(chan);
562                         if ((!ret) && (chan->desc->cyclic))
563                                 stm32_dma_configure_next_sg(chan);
564                 }
565         }
566         spin_unlock_irqrestore(&chan->vchan.lock, flags);
567 }
568
569 static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
570                                     enum dma_transfer_direction direction,
571                                     enum dma_slave_buswidth *buswidth)
572 {
573         enum dma_slave_buswidth src_addr_width, dst_addr_width;
574         int src_bus_width, dst_bus_width;
575         int src_burst_size, dst_burst_size;
576         u32 src_maxburst, dst_maxburst;
577         dma_addr_t src_addr, dst_addr;
578         u32 dma_scr = 0;
579
580         src_addr_width = chan->dma_sconfig.src_addr_width;
581         dst_addr_width = chan->dma_sconfig.dst_addr_width;
582         src_maxburst = chan->dma_sconfig.src_maxburst;
583         dst_maxburst = chan->dma_sconfig.dst_maxburst;
584         src_addr = chan->dma_sconfig.src_addr;
585         dst_addr = chan->dma_sconfig.dst_addr;
586
587         switch (direction) {
588         case DMA_MEM_TO_DEV:
589                 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
590                 if (dst_bus_width < 0)
591                         return dst_bus_width;
592
593                 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
594                 if (dst_burst_size < 0)
595                         return dst_burst_size;
596
597                 if (!src_addr_width)
598                         src_addr_width = dst_addr_width;
599
600                 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
601                 if (src_bus_width < 0)
602                         return src_bus_width;
603
604                 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
605                 if (src_burst_size < 0)
606                         return src_burst_size;
607
608                 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
609                         STM32_DMA_SCR_PSIZE(dst_bus_width) |
610                         STM32_DMA_SCR_MSIZE(src_bus_width) |
611                         STM32_DMA_SCR_PBURST(dst_burst_size) |
612                         STM32_DMA_SCR_MBURST(src_burst_size);
613
614                 chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
615                 *buswidth = dst_addr_width;
616                 break;
617
618         case DMA_DEV_TO_MEM:
619                 src_bus_width = stm32_dma_get_width(chan, src_addr_width);
620                 if (src_bus_width < 0)
621                         return src_bus_width;
622
623                 src_burst_size = stm32_dma_get_burst(chan, src_maxburst);
624                 if (src_burst_size < 0)
625                         return src_burst_size;
626
627                 if (!dst_addr_width)
628                         dst_addr_width = src_addr_width;
629
630                 dst_bus_width = stm32_dma_get_width(chan, dst_addr_width);
631                 if (dst_bus_width < 0)
632                         return dst_bus_width;
633
634                 dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst);
635                 if (dst_burst_size < 0)
636                         return dst_burst_size;
637
638                 dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
639                         STM32_DMA_SCR_PSIZE(src_bus_width) |
640                         STM32_DMA_SCR_MSIZE(dst_bus_width) |
641                         STM32_DMA_SCR_PBURST(src_burst_size) |
642                         STM32_DMA_SCR_MBURST(dst_burst_size);
643
644                 chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
645                 *buswidth = chan->dma_sconfig.src_addr_width;
646                 break;
647
648         default:
649                 dev_err(chan2dev(chan), "Dma direction is not supported\n");
650                 return -EINVAL;
651         }
652
653         stm32_dma_set_fifo_config(chan, src_maxburst, dst_maxburst);
654
655         chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK |
656                         STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK |
657                         STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK);
658         chan->chan_reg.dma_scr |= dma_scr;
659
660         return 0;
661 }
662
663 static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs)
664 {
665         memset(regs, 0, sizeof(struct stm32_dma_chan_reg));
666 }
667
668 static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg(
669         struct dma_chan *c, struct scatterlist *sgl,
670         u32 sg_len, enum dma_transfer_direction direction,
671         unsigned long flags, void *context)
672 {
673         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
674         struct stm32_dma_desc *desc;
675         struct scatterlist *sg;
676         enum dma_slave_buswidth buswidth;
677         u32 nb_data_items;
678         int i, ret;
679
680         if (!chan->config_init) {
681                 dev_err(chan2dev(chan), "dma channel is not configured\n");
682                 return NULL;
683         }
684
685         if (sg_len < 1) {
686                 dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len);
687                 return NULL;
688         }
689
690         desc = stm32_dma_alloc_desc(sg_len);
691         if (!desc)
692                 return NULL;
693
694         ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
695         if (ret < 0)
696                 goto err;
697
698         /* Set peripheral flow controller */
699         if (chan->dma_sconfig.device_fc)
700                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL;
701         else
702                 chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
703
704         for_each_sg(sgl, sg, sg_len, i) {
705                 desc->sg_req[i].len = sg_dma_len(sg);
706
707                 nb_data_items = desc->sg_req[i].len / buswidth;
708                 if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
709                         dev_err(chan2dev(chan), "nb items not supported\n");
710                         goto err;
711                 }
712
713                 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
714                 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
715                 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
716                 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
717                 desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg);
718                 desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg);
719                 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
720         }
721
722         desc->num_sgs = sg_len;
723         desc->cyclic = false;
724
725         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
726
727 err:
728         kfree(desc);
729         return NULL;
730 }
731
732 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic(
733         struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len,
734         size_t period_len, enum dma_transfer_direction direction,
735         unsigned long flags)
736 {
737         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
738         struct stm32_dma_desc *desc;
739         enum dma_slave_buswidth buswidth;
740         u32 num_periods, nb_data_items;
741         int i, ret;
742
743         if (!buf_len || !period_len) {
744                 dev_err(chan2dev(chan), "Invalid buffer/period len\n");
745                 return NULL;
746         }
747
748         if (!chan->config_init) {
749                 dev_err(chan2dev(chan), "dma channel is not configured\n");
750                 return NULL;
751         }
752
753         if (buf_len % period_len) {
754                 dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
755                 return NULL;
756         }
757
758         /*
759          * We allow to take more number of requests till DMA is
760          * not started. The driver will loop over all requests.
761          * Once DMA is started then new requests can be queued only after
762          * terminating the DMA.
763          */
764         if (chan->busy) {
765                 dev_err(chan2dev(chan), "Request not allowed when dma busy\n");
766                 return NULL;
767         }
768
769         ret = stm32_dma_set_xfer_param(chan, direction, &buswidth);
770         if (ret < 0)
771                 return NULL;
772
773         nb_data_items = period_len / buswidth;
774         if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) {
775                 dev_err(chan2dev(chan), "number of items not supported\n");
776                 return NULL;
777         }
778
779         /*  Enable Circular mode or double buffer mode */
780         if (buf_len == period_len)
781                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC;
782         else
783                 chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM;
784
785         /* Clear periph ctrl if client set it */
786         chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL;
787
788         num_periods = buf_len / period_len;
789
790         desc = stm32_dma_alloc_desc(num_periods);
791         if (!desc)
792                 return NULL;
793
794         for (i = 0; i < num_periods; i++) {
795                 desc->sg_req[i].len = period_len;
796
797                 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
798                 desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr;
799                 desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr;
800                 desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar;
801                 desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr;
802                 desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr;
803                 desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items;
804                 buf_addr += period_len;
805         }
806
807         desc->num_sgs = num_periods;
808         desc->cyclic = true;
809
810         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
811 }
812
813 static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
814         struct dma_chan *c, dma_addr_t dest,
815         dma_addr_t src, size_t len, unsigned long flags)
816 {
817         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
818         u32 num_sgs;
819         struct stm32_dma_desc *desc;
820         size_t xfer_count, offset;
821         int i;
822
823         num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS);
824         desc = stm32_dma_alloc_desc(num_sgs);
825         if (!desc)
826                 return NULL;
827
828         for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) {
829                 xfer_count = min_t(size_t, len - offset,
830                                    STM32_DMA_MAX_DATA_ITEMS);
831
832                 desc->sg_req[i].len = xfer_count;
833
834                 stm32_dma_clear_reg(&desc->sg_req[i].chan_reg);
835                 desc->sg_req[i].chan_reg.dma_scr =
836                         STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) |
837                         STM32_DMA_SCR_MINC |
838                         STM32_DMA_SCR_PINC |
839                         STM32_DMA_SCR_TCIE |
840                         STM32_DMA_SCR_TEIE;
841                 desc->sg_req[i].chan_reg.dma_sfcr = STM32_DMA_SFCR_DMDIS |
842                         STM32_DMA_SFCR_FTH(STM32_DMA_FIFO_THRESHOLD_FULL) |
843                         STM32_DMA_SFCR_FEIE;
844                 desc->sg_req[i].chan_reg.dma_spar = src + offset;
845                 desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset;
846                 desc->sg_req[i].chan_reg.dma_sndtr = xfer_count;
847         }
848
849         desc->num_sgs = num_sgs;
850         desc->cyclic = false;
851
852         return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
853 }
854
855 static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
856                                      struct stm32_dma_desc *desc,
857                                      u32 next_sg)
858 {
859         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
860         u32 dma_scr, width, residue, count;
861         int i;
862
863         residue = 0;
864
865         for (i = next_sg; i < desc->num_sgs; i++)
866                 residue += desc->sg_req[i].len;
867
868         if (next_sg != 0) {
869                 dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
870                 width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
871                 count = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
872
873                 residue += count << width;
874         }
875
876         return residue;
877 }
878
879 static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
880                                            dma_cookie_t cookie,
881                                            struct dma_tx_state *state)
882 {
883         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
884         struct virt_dma_desc *vdesc;
885         enum dma_status status;
886         unsigned long flags;
887         u32 residue = 0;
888
889         status = dma_cookie_status(c, cookie, state);
890         if ((status == DMA_COMPLETE) || (!state))
891                 return status;
892
893         spin_lock_irqsave(&chan->vchan.lock, flags);
894         vdesc = vchan_find_desc(&chan->vchan, cookie);
895         if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
896                 residue = stm32_dma_desc_residue(chan, chan->desc,
897                                                  chan->next_sg);
898         else if (vdesc)
899                 residue = stm32_dma_desc_residue(chan,
900                                                  to_stm32_dma_desc(vdesc), 0);
901         dma_set_residue(state, residue);
902
903         spin_unlock_irqrestore(&chan->vchan.lock, flags);
904
905         return status;
906 }
907
908 static int stm32_dma_alloc_chan_resources(struct dma_chan *c)
909 {
910         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
911         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
912         int ret;
913
914         chan->config_init = false;
915         ret = clk_prepare_enable(dmadev->clk);
916         if (ret < 0) {
917                 dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret);
918                 return ret;
919         }
920
921         ret = stm32_dma_disable_chan(chan);
922         if (ret < 0)
923                 clk_disable_unprepare(dmadev->clk);
924
925         return ret;
926 }
927
928 static void stm32_dma_free_chan_resources(struct dma_chan *c)
929 {
930         struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
931         struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
932         unsigned long flags;
933
934         dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);
935
936         if (chan->busy) {
937                 spin_lock_irqsave(&chan->vchan.lock, flags);
938                 stm32_dma_stop(chan);
939                 chan->desc = NULL;
940                 spin_unlock_irqrestore(&chan->vchan.lock, flags);
941         }
942
943         clk_disable_unprepare(dmadev->clk);
944
945         vchan_free_chan_resources(to_virt_chan(c));
946 }
947
948 static void stm32_dma_desc_free(struct virt_dma_desc *vdesc)
949 {
950         kfree(container_of(vdesc, struct stm32_dma_desc, vdesc));
951 }
952
953 static void stm32_dma_set_config(struct stm32_dma_chan *chan,
954                           struct stm32_dma_cfg *cfg)
955 {
956         stm32_dma_clear_reg(&chan->chan_reg);
957
958         chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK;
959         chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line);
960
961         /* Enable Interrupts  */
962         chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE;
963
964         chan->chan_reg.dma_sfcr = cfg->threshold & STM32_DMA_SFCR_FTH_MASK;
965 }
966
967 static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
968                                            struct of_dma *ofdma)
969 {
970         struct stm32_dma_device *dmadev = ofdma->of_dma_data;
971         struct stm32_dma_cfg cfg;
972         struct stm32_dma_chan *chan;
973         struct dma_chan *c;
974
975         if (dma_spec->args_count < 4)
976                 return NULL;
977
978         cfg.channel_id = dma_spec->args[0];
979         cfg.request_line = dma_spec->args[1];
980         cfg.stream_config = dma_spec->args[2];
981         cfg.threshold = dma_spec->args[3];
982
983         if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >=
984                                 STM32_DMA_MAX_REQUEST_ID))
985                 return NULL;
986
987         chan = &dmadev->chan[cfg.channel_id];
988
989         c = dma_get_slave_channel(&chan->vchan.chan);
990         if (c)
991                 stm32_dma_set_config(chan, &cfg);
992
993         return c;
994 }
995
996 static const struct of_device_id stm32_dma_of_match[] = {
997         { .compatible = "st,stm32-dma", },
998         { /* sentinel */ },
999 };
1000 MODULE_DEVICE_TABLE(of, stm32_dma_of_match);
1001
1002 static int stm32_dma_probe(struct platform_device *pdev)
1003 {
1004         struct stm32_dma_chan *chan;
1005         struct stm32_dma_device *dmadev;
1006         struct dma_device *dd;
1007         const struct of_device_id *match;
1008         struct resource *res;
1009         int i, ret;
1010
1011         match = of_match_device(stm32_dma_of_match, &pdev->dev);
1012         if (!match) {
1013                 dev_err(&pdev->dev, "Error: No device match found\n");
1014                 return -ENODEV;
1015         }
1016
1017         dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL);
1018         if (!dmadev)
1019                 return -ENOMEM;
1020
1021         dd = &dmadev->ddev;
1022
1023         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1024         dmadev->base = devm_ioremap_resource(&pdev->dev, res);
1025         if (IS_ERR(dmadev->base))
1026                 return PTR_ERR(dmadev->base);
1027
1028         dmadev->clk = devm_clk_get(&pdev->dev, NULL);
1029         if (IS_ERR(dmadev->clk)) {
1030                 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1031                 return PTR_ERR(dmadev->clk);
1032         }
1033
1034         dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node,
1035                                                 "st,mem2mem");
1036
1037         dmadev->rst = devm_reset_control_get(&pdev->dev, NULL);
1038         if (!IS_ERR(dmadev->rst)) {
1039                 reset_control_assert(dmadev->rst);
1040                 udelay(2);
1041                 reset_control_deassert(dmadev->rst);
1042         }
1043
1044         dma_cap_set(DMA_SLAVE, dd->cap_mask);
1045         dma_cap_set(DMA_PRIVATE, dd->cap_mask);
1046         dma_cap_set(DMA_CYCLIC, dd->cap_mask);
1047         dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources;
1048         dd->device_free_chan_resources = stm32_dma_free_chan_resources;
1049         dd->device_tx_status = stm32_dma_tx_status;
1050         dd->device_issue_pending = stm32_dma_issue_pending;
1051         dd->device_prep_slave_sg = stm32_dma_prep_slave_sg;
1052         dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
1053         dd->device_config = stm32_dma_slave_config;
1054         dd->device_terminate_all = stm32_dma_terminate_all;
1055         dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1056                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1057                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1058         dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1059                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1060                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
1061         dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1062         dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1063         dd->dev = &pdev->dev;
1064         INIT_LIST_HEAD(&dd->channels);
1065
1066         if (dmadev->mem2mem) {
1067                 dma_cap_set(DMA_MEMCPY, dd->cap_mask);
1068                 dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy;
1069                 dd->directions |= BIT(DMA_MEM_TO_MEM);
1070         }
1071
1072         for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1073                 chan = &dmadev->chan[i];
1074                 chan->id = i;
1075                 chan->vchan.desc_free = stm32_dma_desc_free;
1076                 vchan_init(&chan->vchan, dd);
1077         }
1078
1079         ret = dma_async_device_register(dd);
1080         if (ret)
1081                 return ret;
1082
1083         for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) {
1084                 chan = &dmadev->chan[i];
1085                 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1086                 if (!res) {
1087                         ret = -EINVAL;
1088                         dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1089                         goto err_unregister;
1090                 }
1091                 chan->irq = res->start;
1092                 ret = devm_request_irq(&pdev->dev, chan->irq,
1093                                        stm32_dma_chan_irq, 0,
1094                                        dev_name(chan2dev(chan)), chan);
1095                 if (ret) {
1096                         dev_err(&pdev->dev,
1097                                 "request_irq failed with err %d channel %d\n",
1098                                 ret, i);
1099                         goto err_unregister;
1100                 }
1101         }
1102
1103         ret = of_dma_controller_register(pdev->dev.of_node,
1104                                          stm32_dma_of_xlate, dmadev);
1105         if (ret < 0) {
1106                 dev_err(&pdev->dev,
1107                         "STM32 DMA DMA OF registration failed %d\n", ret);
1108                 goto err_unregister;
1109         }
1110
1111         platform_set_drvdata(pdev, dmadev);
1112
1113         dev_info(&pdev->dev, "STM32 DMA driver registered\n");
1114
1115         return 0;
1116
1117 err_unregister:
1118         dma_async_device_unregister(dd);
1119
1120         return ret;
1121 }
1122
1123 static struct platform_driver stm32_dma_driver = {
1124         .driver = {
1125                 .name = "stm32-dma",
1126                 .of_match_table = stm32_dma_of_match,
1127         },
1128 };
1129
1130 static int __init stm32_dma_init(void)
1131 {
1132         return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe);
1133 }
1134 subsys_initcall(stm32_dma_init);