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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / dma / mxs-dma.c
blob3039bba0e4d559836179fe0f71941da428bd563c
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
4 //
5 // Refer to drivers/dma/imx-sdma.c
6
7 #include <linux/init.h>
8 #include <linux/types.h>
9 #include <linux/mm.h>
10 #include <linux/interrupt.h>
11 #include <linux/clk.h>
12 #include <linux/wait.h>
13 #include <linux/sched.h>
14 #include <linux/semaphore.h>
15 #include <linux/device.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/slab.h>
18 #include <linux/platform_device.h>
19 #include <linux/dmaengine.h>
20 #include <linux/delay.h>
21 #include <linux/module.h>
22 #include <linux/stmp_device.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/of_dma.h>
26 #include <linux/list.h>
27 #include <linux/dma/mxs-dma.h>
28
29 #include <asm/irq.h>
30
31 #include "dmaengine.h"
32
33 /*
34 * NOTE: The term "PIO" throughout the mxs-dma implementation means
35 * PIO mode of mxs apbh-dma and apbx-dma. With this working mode,
36 * dma can program the controller registers of peripheral devices.
37 */
38
39 #define dma_is_apbh(mxs_dma) ((mxs_dma)->type == MXS_DMA_APBH)
40 #define apbh_is_old(mxs_dma) ((mxs_dma)->dev_id == IMX23_DMA)
41
42 #define HW_APBHX_CTRL0 0x000
43 #define BM_APBH_CTRL0_APB_BURST8_EN (1 << 29)
44 #define BM_APBH_CTRL0_APB_BURST_EN (1 << 28)
45 #define BP_APBH_CTRL0_RESET_CHANNEL 16
46 #define HW_APBHX_CTRL1 0x010
47 #define HW_APBHX_CTRL2 0x020
48 #define HW_APBHX_CHANNEL_CTRL 0x030
49 #define BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL 16
50 /*
51 * The offset of NXTCMDAR register is different per both dma type and version,
52 * while stride for each channel is all the same 0x70.
53 */
54 #define HW_APBHX_CHn_NXTCMDAR(d, n) \
55 (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x050 : 0x110) + (n) * 0x70)
56 #define HW_APBHX_CHn_SEMA(d, n) \
57 (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x080 : 0x140) + (n) * 0x70)
58 #define HW_APBHX_CHn_BAR(d, n) \
59 (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x070 : 0x130) + (n) * 0x70)
60 #define HW_APBX_CHn_DEBUG1(d, n) (0x150 + (n) * 0x70)
61
62 /*
63 * ccw bits definitions
64 *
65 * COMMAND: 0..1 (2)
66 * CHAIN: 2 (1)
67 * IRQ: 3 (1)
68 * NAND_LOCK: 4 (1) - not implemented
69 * NAND_WAIT4READY: 5 (1) - not implemented
70 * DEC_SEM: 6 (1)
71 * WAIT4END: 7 (1)
72 * HALT_ON_TERMINATE: 8 (1)
73 * TERMINATE_FLUSH: 9 (1)
74 * RESERVED: 10..11 (2)
75 * PIO_NUM: 12..15 (4)
76 */
77 #define BP_CCW_COMMAND 0
78 #define BM_CCW_COMMAND (3 << 0)
79 #define CCW_CHAIN (1 << 2)
80 #define CCW_IRQ (1 << 3)
81 #define CCW_WAIT4RDY (1 << 5)
82 #define CCW_DEC_SEM (1 << 6)
83 #define CCW_WAIT4END (1 << 7)
84 #define CCW_HALT_ON_TERM (1 << 8)
85 #define CCW_TERM_FLUSH (1 << 9)
86 #define BP_CCW_PIO_NUM 12
87 #define BM_CCW_PIO_NUM (0xf << 12)
88
89 #define BF_CCW(value, field) (((value) << BP_CCW_##field) & BM_CCW_##field)
90
91 #define MXS_DMA_CMD_NO_XFER 0
92 #define MXS_DMA_CMD_WRITE 1
93 #define MXS_DMA_CMD_READ 2
94 #define MXS_DMA_CMD_DMA_SENSE 3 /* not implemented */
95
96 struct mxs_dma_ccw {
97 u32 next;
98 u16 bits;
99 u16 xfer_bytes;
100 #define MAX_XFER_BYTES 0xff00
101 u32 bufaddr;
102 #define MXS_PIO_WORDS 16
103 u32 pio_words[MXS_PIO_WORDS];
104 };
105
106 #define CCW_BLOCK_SIZE (4 * PAGE_SIZE)
107 #define NUM_CCW (int)(CCW_BLOCK_SIZE / sizeof(struct mxs_dma_ccw))
108
109 struct mxs_dma_chan {
110 struct mxs_dma_engine *mxs_dma;
111 struct dma_chan chan;
112 struct dma_async_tx_descriptor desc;
113 struct tasklet_struct tasklet;
114 unsigned int chan_irq;
115 struct mxs_dma_ccw *ccw;
116 dma_addr_t ccw_phys;
117 int desc_count;
118 enum dma_status status;
119 unsigned int flags;
120 bool reset;
121 #define MXS_DMA_SG_LOOP (1 << 0)
122 #define MXS_DMA_USE_SEMAPHORE (1 << 1)
123 };
124
125 #define MXS_DMA_CHANNELS 16
126 #define MXS_DMA_CHANNELS_MASK 0xffff
127
128 enum mxs_dma_devtype {
129 MXS_DMA_APBH,
130 MXS_DMA_APBX,
131 };
132
133 enum mxs_dma_id {
134 IMX23_DMA,
135 IMX28_DMA,
136 };
137
138 struct mxs_dma_engine {
139 enum mxs_dma_id dev_id;
140 enum mxs_dma_devtype type;
141 void __iomem *base;
142 struct clk *clk;
143 struct dma_device dma_device;
144 struct device_dma_parameters dma_parms;
145 struct mxs_dma_chan mxs_chans[MXS_DMA_CHANNELS];
146 struct platform_device *pdev;
147 unsigned int nr_channels;
148 };
149
150 struct mxs_dma_type {
151 enum mxs_dma_id id;
152 enum mxs_dma_devtype type;
153 };
154
155 static struct mxs_dma_type mxs_dma_types[] = {
156 {
157 .id = IMX23_DMA,
158 .type = MXS_DMA_APBH,
159 }, {
160 .id = IMX23_DMA,
161 .type = MXS_DMA_APBX,
162 }, {
163 .id = IMX28_DMA,
164 .type = MXS_DMA_APBH,
165 }, {
166 .id = IMX28_DMA,
167 .type = MXS_DMA_APBX,
168 }
169 };
170
171 static const struct platform_device_id mxs_dma_ids[] = {
172 {
173 .name = "imx23-dma-apbh",
174 .driver_data = (kernel_ulong_t) &mxs_dma_types[0],
175 }, {
176 .name = "imx23-dma-apbx",
177 .driver_data = (kernel_ulong_t) &mxs_dma_types[1],
178 }, {
179 .name = "imx28-dma-apbh",
180 .driver_data = (kernel_ulong_t) &mxs_dma_types[2],
181 }, {
182 .name = "imx28-dma-apbx",
183 .driver_data = (kernel_ulong_t) &mxs_dma_types[3],
184 }, {
185 /* end of list */
186 }
187 };
188
189 static const struct of_device_id mxs_dma_dt_ids[] = {
190 { .compatible = "fsl,imx23-dma-apbh", .data = &mxs_dma_ids[0], },
191 { .compatible = "fsl,imx23-dma-apbx", .data = &mxs_dma_ids[1], },
192 { .compatible = "fsl,imx28-dma-apbh", .data = &mxs_dma_ids[2], },
193 { .compatible = "fsl,imx28-dma-apbx", .data = &mxs_dma_ids[3], },
194 { /* sentinel */ }
195 };
196 MODULE_DEVICE_TABLE(of, mxs_dma_dt_ids);
197
198 static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan)
199 {
200 return container_of(chan, struct mxs_dma_chan, chan);
201 }
202
203 static void mxs_dma_reset_chan(struct dma_chan *chan)
204 {
205 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
206 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
207 int chan_id = mxs_chan->chan.chan_id;
208
209 /*
210 * mxs dma channel resets can cause a channel stall. To recover from a
211 * channel stall, we have to reset the whole DMA engine. To avoid this,
212 * we use cyclic DMA with semaphores, that are enhanced in
213 * mxs_dma_int_handler. To reset the channel, we can simply stop writing
214 * into the semaphore counter.
215 */
216 if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE &&
217 mxs_chan->flags & MXS_DMA_SG_LOOP) {
218 mxs_chan->reset = true;
219 } else if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) {
220 writel(1 << (chan_id + BP_APBH_CTRL0_RESET_CHANNEL),
221 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
222 } else {
223 unsigned long elapsed = 0;
224 const unsigned long max_wait = 50000; /* 50ms */
225 void __iomem *reg_dbg1 = mxs_dma->base +
226 HW_APBX_CHn_DEBUG1(mxs_dma, chan_id);
227
228 /*
229 * On i.MX28 APBX, the DMA channel can stop working if we reset
230 * the channel while it is in READ_FLUSH (0x08) state.
231 * We wait here until we leave the state. Then we trigger the
232 * reset. Waiting a maximum of 50ms, the kernel shouldn't crash
233 * because of this.
234 */
235 while ((readl(reg_dbg1) & 0xf) == 0x8 && elapsed < max_wait) {
236 udelay(100);
237 elapsed += 100;
238 }
239
240 if (elapsed >= max_wait)
241 dev_err(&mxs_chan->mxs_dma->pdev->dev,
242 "Failed waiting for the DMA channel %d to leave state READ_FLUSH, trying to reset channel in READ_FLUSH state now\n",
243 chan_id);
244
245 writel(1 << (chan_id + BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL),
246 mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET);
247 }
248
249 mxs_chan->status = DMA_COMPLETE;
250 }
251
252 static void mxs_dma_enable_chan(struct dma_chan *chan)
253 {
254 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
255 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
256 int chan_id = mxs_chan->chan.chan_id;
257
258 /* set cmd_addr up */
259 writel(mxs_chan->ccw_phys,
260 mxs_dma->base + HW_APBHX_CHn_NXTCMDAR(mxs_dma, chan_id));
261
262 /* write 1 to SEMA to kick off the channel */
263 if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE &&
264 mxs_chan->flags & MXS_DMA_SG_LOOP) {
265 /* A cyclic DMA consists of at least 2 segments, so initialize
266 * the semaphore with 2 so we have enough time to add 1 to the
267 * semaphore if we need to */
268 writel(2, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id));
269 } else {
270 writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id));
271 }
272 mxs_chan->reset = false;
273 }
274
275 static void mxs_dma_disable_chan(struct dma_chan *chan)
276 {
277 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
278
279 mxs_chan->status = DMA_COMPLETE;
280 }
281
282 static int mxs_dma_pause_chan(struct dma_chan *chan)
283 {
284 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
285 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
286 int chan_id = mxs_chan->chan.chan_id;
287
288 /* freeze the channel */
289 if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma))
290 writel(1 << chan_id,
291 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
292 else
293 writel(1 << chan_id,
294 mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET);
295
296 mxs_chan->status = DMA_PAUSED;
297 return 0;
298 }
299
300 static int mxs_dma_resume_chan(struct dma_chan *chan)
301 {
302 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
303 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
304 int chan_id = mxs_chan->chan.chan_id;
305
306 /* unfreeze the channel */
307 if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma))
308 writel(1 << chan_id,
309 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_CLR);
310 else
311 writel(1 << chan_id,
312 mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_CLR);
313
314 mxs_chan->status = DMA_IN_PROGRESS;
315 return 0;
316 }
317
318 static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx)
319 {
320 return dma_cookie_assign(tx);
321 }
322
323 static void mxs_dma_tasklet(unsigned long data)
324 {
325 struct mxs_dma_chan *mxs_chan = (struct mxs_dma_chan *) data;
326
327 dmaengine_desc_get_callback_invoke(&mxs_chan->desc, NULL);
328 }
329
330 static int mxs_dma_irq_to_chan(struct mxs_dma_engine *mxs_dma, int irq)
331 {
332 int i;
333
334 for (i = 0; i != mxs_dma->nr_channels; ++i)
335 if (mxs_dma->mxs_chans[i].chan_irq == irq)
336 return i;
337
338 return -EINVAL;
339 }
340
341 static irqreturn_t mxs_dma_int_handler(int irq, void *dev_id)
342 {
343 struct mxs_dma_engine *mxs_dma = dev_id;
344 struct mxs_dma_chan *mxs_chan;
345 u32 completed;
346 u32 err;
347 int chan = mxs_dma_irq_to_chan(mxs_dma, irq);
348
349 if (chan < 0)
350 return IRQ_NONE;
351
352 /* completion status */
353 completed = readl(mxs_dma->base + HW_APBHX_CTRL1);
354 completed = (completed >> chan) & 0x1;
355
356 /* Clear interrupt */
357 writel((1 << chan),
358 mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR);
359
360 /* error status */
361 err = readl(mxs_dma->base + HW_APBHX_CTRL2);
362 err &= (1 << (MXS_DMA_CHANNELS + chan)) | (1 << chan);
363
364 /*
365 * error status bit is in the upper 16 bits, error irq bit in the lower
366 * 16 bits. We transform it into a simpler error code:
367 * err: 0x00 = no error, 0x01 = TERMINATION, 0x02 = BUS_ERROR
368 */
369 err = (err >> (MXS_DMA_CHANNELS + chan)) + (err >> chan);
370
371 /* Clear error irq */
372 writel((1 << chan),
373 mxs_dma->base + HW_APBHX_CTRL2 + STMP_OFFSET_REG_CLR);
374
375 /*
376 * When both completion and error of termination bits set at the
377 * same time, we do not take it as an error. IOW, it only becomes
378 * an error we need to handle here in case of either it's a bus
379 * error or a termination error with no completion. 0x01 is termination
380 * error, so we can subtract err & completed to get the real error case.
381 */
382 err -= err & completed;
383
384 mxs_chan = &mxs_dma->mxs_chans[chan];
385
386 if (err) {
387 dev_dbg(mxs_dma->dma_device.dev,
388 "%s: error in channel %d\n", __func__,
389 chan);
390 mxs_chan->status = DMA_ERROR;
391 mxs_dma_reset_chan(&mxs_chan->chan);
392 } else if (mxs_chan->status != DMA_COMPLETE) {
393 if (mxs_chan->flags & MXS_DMA_SG_LOOP) {
394 mxs_chan->status = DMA_IN_PROGRESS;
395 if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE)
396 writel(1, mxs_dma->base +
397 HW_APBHX_CHn_SEMA(mxs_dma, chan));
398 } else {
399 mxs_chan->status = DMA_COMPLETE;
400 }
401 }
402
403 if (mxs_chan->status == DMA_COMPLETE) {
404 if (mxs_chan->reset)
405 return IRQ_HANDLED;
406 dma_cookie_complete(&mxs_chan->desc);
407 }
408
409 /* schedule tasklet on this channel */
410 tasklet_schedule(&mxs_chan->tasklet);
411
412 return IRQ_HANDLED;
413 }
414
415 static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
416 {
417 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
418 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
419 int ret;
420
421 mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev,
422 CCW_BLOCK_SIZE,
423 &mxs_chan->ccw_phys, GFP_KERNEL);
424 if (!mxs_chan->ccw) {
425 ret = -ENOMEM;
426 goto err_alloc;
427 }
428
429 ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
430 0, "mxs-dma", mxs_dma);
431 if (ret)
432 goto err_irq;
433
434 ret = clk_prepare_enable(mxs_dma->clk);
435 if (ret)
436 goto err_clk;
437
438 mxs_dma_reset_chan(chan);
439
440 dma_async_tx_descriptor_init(&mxs_chan->desc, chan);
441 mxs_chan->desc.tx_submit = mxs_dma_tx_submit;
442
443 /* the descriptor is ready */
444 async_tx_ack(&mxs_chan->desc);
445
446 return 0;
447
448 err_clk:
449 free_irq(mxs_chan->chan_irq, mxs_dma);
450 err_irq:
451 dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
452 mxs_chan->ccw, mxs_chan->ccw_phys);
453 err_alloc:
454 return ret;
455 }
456
457 static void mxs_dma_free_chan_resources(struct dma_chan *chan)
458 {
459 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
460 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
461
462 mxs_dma_disable_chan(chan);
463
464 free_irq(mxs_chan->chan_irq, mxs_dma);
465
466 dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
467 mxs_chan->ccw, mxs_chan->ccw_phys);
468
469 clk_disable_unprepare(mxs_dma->clk);
470 }
471
472 /*
473 * How to use the flags for ->device_prep_slave_sg() :
474 * [1] If there is only one DMA command in the DMA chain, the code should be:
475 * ......
476 * ->device_prep_slave_sg(DMA_CTRL_ACK);
477 * ......
478 * [2] If there are two DMA commands in the DMA chain, the code should be
479 * ......
480 * ->device_prep_slave_sg(0);
481 * ......
482 * ->device_prep_slave_sg(DMA_CTRL_ACK);
483 * ......
484 * [3] If there are more than two DMA commands in the DMA chain, the code
485 * should be:
486 * ......
487 * ->device_prep_slave_sg(0); // First
488 * ......
489 * ->device_prep_slave_sg(DMA_CTRL_ACK]);
490 * ......
491 * ->device_prep_slave_sg(DMA_CTRL_ACK); // Last
492 * ......
493 */
494 static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
495 struct dma_chan *chan, struct scatterlist *sgl,
496 unsigned int sg_len, enum dma_transfer_direction direction,
497 unsigned long flags, void *context)
498 {
499 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
500 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
501 struct mxs_dma_ccw *ccw;
502 struct scatterlist *sg;
503 u32 i, j;
504 u32 *pio;
505 int idx = 0;
506
507 if (mxs_chan->status == DMA_IN_PROGRESS)
508 idx = mxs_chan->desc_count;
509
510 if (sg_len + idx > NUM_CCW) {
511 dev_err(mxs_dma->dma_device.dev,
512 "maximum number of sg exceeded: %d > %d\n",
513 sg_len, NUM_CCW);
514 goto err_out;
515 }
516
517 mxs_chan->status = DMA_IN_PROGRESS;
518 mxs_chan->flags = 0;
519
520 /*
521 * If the sg is prepared with append flag set, the sg
522 * will be appended to the last prepared sg.
523 */
524 if (idx) {
525 BUG_ON(idx < 1);
526 ccw = &mxs_chan->ccw[idx - 1];
527 ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx;
528 ccw->bits |= CCW_CHAIN;
529 ccw->bits &= ~CCW_IRQ;
530 ccw->bits &= ~CCW_DEC_SEM;
531 } else {
532 idx = 0;
533 }
534
535 if (direction == DMA_TRANS_NONE) {
536 ccw = &mxs_chan->ccw[idx++];
537 pio = (u32 *) sgl;
538
539 for (j = 0; j < sg_len;)
540 ccw->pio_words[j++] = *pio++;
541
542 ccw->bits = 0;
543 ccw->bits |= CCW_IRQ;
544 ccw->bits |= CCW_DEC_SEM;
545 if (flags & MXS_DMA_CTRL_WAIT4END)
546 ccw->bits |= CCW_WAIT4END;
547 ccw->bits |= CCW_HALT_ON_TERM;
548 ccw->bits |= CCW_TERM_FLUSH;
549 ccw->bits |= BF_CCW(sg_len, PIO_NUM);
550 ccw->bits |= BF_CCW(MXS_DMA_CMD_NO_XFER, COMMAND);
551 if (flags & MXS_DMA_CTRL_WAIT4RDY)
552 ccw->bits |= CCW_WAIT4RDY;
553 } else {
554 for_each_sg(sgl, sg, sg_len, i) {
555 if (sg_dma_len(sg) > MAX_XFER_BYTES) {
556 dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n",
557 sg_dma_len(sg), MAX_XFER_BYTES);
558 goto err_out;
559 }
560
561 ccw = &mxs_chan->ccw[idx++];
562
563 ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx;
564 ccw->bufaddr = sg->dma_address;
565 ccw->xfer_bytes = sg_dma_len(sg);
566
567 ccw->bits = 0;
568 ccw->bits |= CCW_CHAIN;
569 ccw->bits |= CCW_HALT_ON_TERM;
570 ccw->bits |= CCW_TERM_FLUSH;
571 ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ?
572 MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ,
573 COMMAND);
574
575 if (i + 1 == sg_len) {
576 ccw->bits &= ~CCW_CHAIN;
577 ccw->bits |= CCW_IRQ;
578 ccw->bits |= CCW_DEC_SEM;
579 if (flags & MXS_DMA_CTRL_WAIT4END)
580 ccw->bits |= CCW_WAIT4END;
581 }
582 }
583 }
584 mxs_chan->desc_count = idx;
585
586 return &mxs_chan->desc;
587
588 err_out:
589 mxs_chan->status = DMA_ERROR;
590 return NULL;
591 }
592
593 static struct dma_async_tx_descriptor *mxs_dma_prep_dma_cyclic(
594 struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
595 size_t period_len, enum dma_transfer_direction direction,
596 unsigned long flags)
597 {
598 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
599 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
600 u32 num_periods = buf_len / period_len;
601 u32 i = 0, buf = 0;
602
603 if (mxs_chan->status == DMA_IN_PROGRESS)
604 return NULL;
605
606 mxs_chan->status = DMA_IN_PROGRESS;
607 mxs_chan->flags |= MXS_DMA_SG_LOOP;
608 mxs_chan->flags |= MXS_DMA_USE_SEMAPHORE;
609
610 if (num_periods > NUM_CCW) {
611 dev_err(mxs_dma->dma_device.dev,
612 "maximum number of sg exceeded: %d > %d\n",
613 num_periods, NUM_CCW);
614 goto err_out;
615 }
616
617 if (period_len > MAX_XFER_BYTES) {
618 dev_err(mxs_dma->dma_device.dev,
619 "maximum period size exceeded: %zu > %d\n",
620 period_len, MAX_XFER_BYTES);
621 goto err_out;
622 }
623
624 while (buf < buf_len) {
625 struct mxs_dma_ccw *ccw = &mxs_chan->ccw[i];
626
627 if (i + 1 == num_periods)
628 ccw->next = mxs_chan->ccw_phys;
629 else
630 ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * (i + 1);
631
632 ccw->bufaddr = dma_addr;
633 ccw->xfer_bytes = period_len;
634
635 ccw->bits = 0;
636 ccw->bits |= CCW_CHAIN;
637 ccw->bits |= CCW_IRQ;
638 ccw->bits |= CCW_HALT_ON_TERM;
639 ccw->bits |= CCW_TERM_FLUSH;
640 ccw->bits |= CCW_DEC_SEM;
641 ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ?
642 MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND);
643
644 dma_addr += period_len;
645 buf += period_len;
646
647 i++;
648 }
649 mxs_chan->desc_count = i;
650
651 return &mxs_chan->desc;
652
653 err_out:
654 mxs_chan->status = DMA_ERROR;
655 return NULL;
656 }
657
658 static int mxs_dma_terminate_all(struct dma_chan *chan)
659 {
660 mxs_dma_reset_chan(chan);
661 mxs_dma_disable_chan(chan);
662
663 return 0;
664 }
665
666 static enum dma_status mxs_dma_tx_status(struct dma_chan *chan,
667 dma_cookie_t cookie, struct dma_tx_state *txstate)
668 {
669 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
670 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
671 u32 residue = 0;
672
673 if (mxs_chan->status == DMA_IN_PROGRESS &&
674 mxs_chan->flags & MXS_DMA_SG_LOOP) {
675 struct mxs_dma_ccw *last_ccw;
676 u32 bar;
677
678 last_ccw = &mxs_chan->ccw[mxs_chan->desc_count - 1];
679 residue = last_ccw->xfer_bytes + last_ccw->bufaddr;
680
681 bar = readl(mxs_dma->base +
682 HW_APBHX_CHn_BAR(mxs_dma, chan->chan_id));
683 residue -= bar;
684 }
685
686 dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie,
687 residue);
688
689 return mxs_chan->status;
690 }
691
692 static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
693 {
694 int ret;
695
696 ret = clk_prepare_enable(mxs_dma->clk);
697 if (ret)
698 return ret;
699
700 ret = stmp_reset_block(mxs_dma->base);
701 if (ret)
702 goto err_out;
703
704 /* enable apbh burst */
705 if (dma_is_apbh(mxs_dma)) {
706 writel(BM_APBH_CTRL0_APB_BURST_EN,
707 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
708 writel(BM_APBH_CTRL0_APB_BURST8_EN,
709 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
710 }
711
712 /* enable irq for all the channels */
713 writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS,
714 mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_SET);
715
716 err_out:
717 clk_disable_unprepare(mxs_dma->clk);
718 return ret;
719 }
720
721 struct mxs_dma_filter_param {
722 unsigned int chan_id;
723 };
724
725 static bool mxs_dma_filter_fn(struct dma_chan *chan, void *fn_param)
726 {
727 struct mxs_dma_filter_param *param = fn_param;
728 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
729 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
730 int chan_irq;
731
732 if (chan->chan_id != param->chan_id)
733 return false;
734
735 chan_irq = platform_get_irq(mxs_dma->pdev, param->chan_id);
736 if (chan_irq < 0)
737 return false;
738
739 mxs_chan->chan_irq = chan_irq;
740
741 return true;
742 }
743
744 static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec,
745 struct of_dma *ofdma)
746 {
747 struct mxs_dma_engine *mxs_dma = ofdma->of_dma_data;
748 dma_cap_mask_t mask = mxs_dma->dma_device.cap_mask;
749 struct mxs_dma_filter_param param;
750
751 if (dma_spec->args_count != 1)
752 return NULL;
753
754 param.chan_id = dma_spec->args[0];
755
756 if (param.chan_id >= mxs_dma->nr_channels)
757 return NULL;
758
759 return __dma_request_channel(&mask, mxs_dma_filter_fn, &param,
760 ofdma->of_node);
761 }
762
763 static int __init mxs_dma_probe(struct platform_device *pdev)
764 {
765 struct device_node *np = pdev->dev.of_node;
766 const struct platform_device_id *id_entry;
767 const struct of_device_id *of_id;
768 const struct mxs_dma_type *dma_type;
769 struct mxs_dma_engine *mxs_dma;
770 struct resource *iores;
771 int ret, i;
772
773 mxs_dma = devm_kzalloc(&pdev->dev, sizeof(*mxs_dma), GFP_KERNEL);
774 if (!mxs_dma)
775 return -ENOMEM;
776
777 ret = of_property_read_u32(np, "dma-channels", &mxs_dma->nr_channels);
778 if (ret) {
779 dev_err(&pdev->dev, "failed to read dma-channels\n");
780 return ret;
781 }
782
783 of_id = of_match_device(mxs_dma_dt_ids, &pdev->dev);
784 if (of_id)
785 id_entry = of_id->data;
786 else
787 id_entry = platform_get_device_id(pdev);
788
789 dma_type = (struct mxs_dma_type *)id_entry->driver_data;
790 mxs_dma->type = dma_type->type;
791 mxs_dma->dev_id = dma_type->id;
792
793 iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
794 mxs_dma->base = devm_ioremap_resource(&pdev->dev, iores);
795 if (IS_ERR(mxs_dma->base))
796 return PTR_ERR(mxs_dma->base);
797
798 mxs_dma->clk = devm_clk_get(&pdev->dev, NULL);
799 if (IS_ERR(mxs_dma->clk))
800 return PTR_ERR(mxs_dma->clk);
801
802 dma_cap_set(DMA_SLAVE, mxs_dma->dma_device.cap_mask);
803 dma_cap_set(DMA_CYCLIC, mxs_dma->dma_device.cap_mask);
804
805 INIT_LIST_HEAD(&mxs_dma->dma_device.channels);
806
807 /* Initialize channel parameters */
808 for (i = 0; i < MXS_DMA_CHANNELS; i++) {
809 struct mxs_dma_chan *mxs_chan = &mxs_dma->mxs_chans[i];
810
811 mxs_chan->mxs_dma = mxs_dma;
812 mxs_chan->chan.device = &mxs_dma->dma_device;
813 dma_cookie_init(&mxs_chan->chan);
814
815 tasklet_init(&mxs_chan->tasklet, mxs_dma_tasklet,
816 (unsigned long) mxs_chan);
817
818
819 /* Add the channel to mxs_chan list */
820 list_add_tail(&mxs_chan->chan.device_node,
821 &mxs_dma->dma_device.channels);
822 }
823
824 ret = mxs_dma_init(mxs_dma);
825 if (ret)
826 return ret;
827
828 mxs_dma->pdev = pdev;
829 mxs_dma->dma_device.dev = &pdev->dev;
830
831 /* mxs_dma gets 65535 bytes maximum sg size */
832 mxs_dma->dma_device.dev->dma_parms = &mxs_dma->dma_parms;
833 dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES);
834
835 mxs_dma->dma_device.device_alloc_chan_resources = mxs_dma_alloc_chan_resources;
836 mxs_dma->dma_device.device_free_chan_resources = mxs_dma_free_chan_resources;
837 mxs_dma->dma_device.device_tx_status = mxs_dma_tx_status;
838 mxs_dma->dma_device.device_prep_slave_sg = mxs_dma_prep_slave_sg;
839 mxs_dma->dma_device.device_prep_dma_cyclic = mxs_dma_prep_dma_cyclic;
840 mxs_dma->dma_device.device_pause = mxs_dma_pause_chan;
841 mxs_dma->dma_device.device_resume = mxs_dma_resume_chan;
842 mxs_dma->dma_device.device_terminate_all = mxs_dma_terminate_all;
843 mxs_dma->dma_device.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
844 mxs_dma->dma_device.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
845 mxs_dma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
846 mxs_dma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
847 mxs_dma->dma_device.device_issue_pending = mxs_dma_enable_chan;
848
849 ret = dmaenginem_async_device_register(&mxs_dma->dma_device);
850 if (ret) {
851 dev_err(mxs_dma->dma_device.dev, "unable to register\n");
852 return ret;
853 }
854
855 ret = of_dma_controller_register(np, mxs_dma_xlate, mxs_dma);
856 if (ret) {
857 dev_err(mxs_dma->dma_device.dev,
858 "failed to register controller\n");
859 }
860
861 dev_info(mxs_dma->dma_device.dev, "initialized\n");
862
863 return 0;
864 }
865
866 static struct platform_driver mxs_dma_driver = {
867 .driver = {
868 .name = "mxs-dma",
869 .of_match_table = mxs_dma_dt_ids,
870 },
871 .id_table = mxs_dma_ids,
872 };
873
874 static int __init mxs_dma_module_init(void)
875 {
876 return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe);
877 }
878 subsys_initcall(mxs_dma_module_init);
Linux with added FPC-III support