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powercap: restrict energy meter to root access
[linux/fpc-iii.git] / drivers / dma / zx296702_dma.c
blob8e55403847b243394dcdde912fd4e02ba443bc3d
1 /*
2 * Copyright 2015 Linaro.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8 #include <linux/sched.h>
9 #include <linux/device.h>
10 #include <linux/dmaengine.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/dmapool.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/of_device.h>
21 #include <linux/of.h>
22 #include <linux/clk.h>
23 #include <linux/of_dma.h>
24
25 #include "virt-dma.h"
26
27 #define DRIVER_NAME "zx-dma"
28 #define DMA_ALIGN 4
29 #define DMA_MAX_SIZE (0x10000 - 512)
30 #define LLI_BLOCK_SIZE (4 * PAGE_SIZE)
31
32 #define REG_ZX_SRC_ADDR 0x00
33 #define REG_ZX_DST_ADDR 0x04
34 #define REG_ZX_TX_X_COUNT 0x08
35 #define REG_ZX_TX_ZY_COUNT 0x0c
36 #define REG_ZX_SRC_ZY_STEP 0x10
37 #define REG_ZX_DST_ZY_STEP 0x14
38 #define REG_ZX_LLI_ADDR 0x1c
39 #define REG_ZX_CTRL 0x20
40 #define REG_ZX_TC_IRQ 0x800
41 #define REG_ZX_SRC_ERR_IRQ 0x804
42 #define REG_ZX_DST_ERR_IRQ 0x808
43 #define REG_ZX_CFG_ERR_IRQ 0x80c
44 #define REG_ZX_TC_IRQ_RAW 0x810
45 #define REG_ZX_SRC_ERR_IRQ_RAW 0x814
46 #define REG_ZX_DST_ERR_IRQ_RAW 0x818
47 #define REG_ZX_CFG_ERR_IRQ_RAW 0x81c
48 #define REG_ZX_STATUS 0x820
49 #define REG_ZX_DMA_GRP_PRIO 0x824
50 #define REG_ZX_DMA_ARB 0x828
51
52 #define ZX_FORCE_CLOSE BIT(31)
53 #define ZX_DST_BURST_WIDTH(x) (((x) & 0x7) << 13)
54 #define ZX_MAX_BURST_LEN 16
55 #define ZX_SRC_BURST_LEN(x) (((x) & 0xf) << 9)
56 #define ZX_SRC_BURST_WIDTH(x) (((x) & 0x7) << 6)
57 #define ZX_IRQ_ENABLE_ALL (3 << 4)
58 #define ZX_DST_FIFO_MODE BIT(3)
59 #define ZX_SRC_FIFO_MODE BIT(2)
60 #define ZX_SOFT_REQ BIT(1)
61 #define ZX_CH_ENABLE BIT(0)
62
63 #define ZX_DMA_BUSWIDTHS \
64 (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
65 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
66 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
67 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
68 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
69
70 enum zx_dma_burst_width {
71 ZX_DMA_WIDTH_8BIT = 0,
72 ZX_DMA_WIDTH_16BIT = 1,
73 ZX_DMA_WIDTH_32BIT = 2,
74 ZX_DMA_WIDTH_64BIT = 3,
75 };
76
77 struct zx_desc_hw {
78 u32 saddr;
79 u32 daddr;
80 u32 src_x;
81 u32 src_zy;
82 u32 src_zy_step;
83 u32 dst_zy_step;
84 u32 reserved1;
85 u32 lli;
86 u32 ctr;
87 u32 reserved[7]; /* pack as hardware registers region size */
88 } __aligned(32);
89
90 struct zx_dma_desc_sw {
91 struct virt_dma_desc vd;
92 dma_addr_t desc_hw_lli;
93 size_t desc_num;
94 size_t size;
95 struct zx_desc_hw *desc_hw;
96 };
97
98 struct zx_dma_phy;
99
100 struct zx_dma_chan {
101 struct dma_slave_config slave_cfg;
102 int id; /* Request phy chan id */
103 u32 ccfg;
104 u32 cyclic;
105 struct virt_dma_chan vc;
106 struct zx_dma_phy *phy;
107 struct list_head node;
108 dma_addr_t dev_addr;
109 enum dma_status status;
110 };
111
112 struct zx_dma_phy {
113 u32 idx;
114 void __iomem *base;
115 struct zx_dma_chan *vchan;
116 struct zx_dma_desc_sw *ds_run;
117 struct zx_dma_desc_sw *ds_done;
118 };
119
120 struct zx_dma_dev {
121 struct dma_device slave;
122 void __iomem *base;
123 spinlock_t lock; /* lock for ch and phy */
124 struct list_head chan_pending;
125 struct zx_dma_phy *phy;
126 struct zx_dma_chan *chans;
127 struct clk *clk;
128 struct dma_pool *pool;
129 u32 dma_channels;
130 u32 dma_requests;
131 int irq;
132 };
133
134 #define to_zx_dma(dmadev) container_of(dmadev, struct zx_dma_dev, slave)
135
136 static struct zx_dma_chan *to_zx_chan(struct dma_chan *chan)
137 {
138 return container_of(chan, struct zx_dma_chan, vc.chan);
139 }
140
141 static void zx_dma_terminate_chan(struct zx_dma_phy *phy, struct zx_dma_dev *d)
142 {
143 u32 val = 0;
144
145 val = readl_relaxed(phy->base + REG_ZX_CTRL);
146 val &= ~ZX_CH_ENABLE;
147 val |= ZX_FORCE_CLOSE;
148 writel_relaxed(val, phy->base + REG_ZX_CTRL);
149
150 val = 0x1 << phy->idx;
151 writel_relaxed(val, d->base + REG_ZX_TC_IRQ_RAW);
152 writel_relaxed(val, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
153 writel_relaxed(val, d->base + REG_ZX_DST_ERR_IRQ_RAW);
154 writel_relaxed(val, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
155 }
156
157 static void zx_dma_set_desc(struct zx_dma_phy *phy, struct zx_desc_hw *hw)
158 {
159 writel_relaxed(hw->saddr, phy->base + REG_ZX_SRC_ADDR);
160 writel_relaxed(hw->daddr, phy->base + REG_ZX_DST_ADDR);
161 writel_relaxed(hw->src_x, phy->base + REG_ZX_TX_X_COUNT);
162 writel_relaxed(0, phy->base + REG_ZX_TX_ZY_COUNT);
163 writel_relaxed(0, phy->base + REG_ZX_SRC_ZY_STEP);
164 writel_relaxed(0, phy->base + REG_ZX_DST_ZY_STEP);
165 writel_relaxed(hw->lli, phy->base + REG_ZX_LLI_ADDR);
166 writel_relaxed(hw->ctr, phy->base + REG_ZX_CTRL);
167 }
168
169 static u32 zx_dma_get_curr_lli(struct zx_dma_phy *phy)
170 {
171 return readl_relaxed(phy->base + REG_ZX_LLI_ADDR);
172 }
173
174 static u32 zx_dma_get_chan_stat(struct zx_dma_dev *d)
175 {
176 return readl_relaxed(d->base + REG_ZX_STATUS);
177 }
178
179 static void zx_dma_init_state(struct zx_dma_dev *d)
180 {
181 /* set same priority */
182 writel_relaxed(0x0, d->base + REG_ZX_DMA_ARB);
183 /* clear all irq */
184 writel_relaxed(0xffffffff, d->base + REG_ZX_TC_IRQ_RAW);
185 writel_relaxed(0xffffffff, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
186 writel_relaxed(0xffffffff, d->base + REG_ZX_DST_ERR_IRQ_RAW);
187 writel_relaxed(0xffffffff, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
188 }
189
190 static int zx_dma_start_txd(struct zx_dma_chan *c)
191 {
192 struct zx_dma_dev *d = to_zx_dma(c->vc.chan.device);
193 struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
194
195 if (!c->phy)
196 return -EAGAIN;
197
198 if (BIT(c->phy->idx) & zx_dma_get_chan_stat(d))
199 return -EAGAIN;
200
201 if (vd) {
202 struct zx_dma_desc_sw *ds =
203 container_of(vd, struct zx_dma_desc_sw, vd);
204 /*
205 * fetch and remove request from vc->desc_issued
206 * so vc->desc_issued only contains desc pending
207 */
208 list_del(&ds->vd.node);
209 c->phy->ds_run = ds;
210 c->phy->ds_done = NULL;
211 /* start dma */
212 zx_dma_set_desc(c->phy, ds->desc_hw);
213 return 0;
214 }
215 c->phy->ds_done = NULL;
216 c->phy->ds_run = NULL;
217 return -EAGAIN;
218 }
219
220 static void zx_dma_task(struct zx_dma_dev *d)
221 {
222 struct zx_dma_phy *p;
223 struct zx_dma_chan *c, *cn;
224 unsigned pch, pch_alloc = 0;
225 unsigned long flags;
226
227 /* check new dma request of running channel in vc->desc_issued */
228 list_for_each_entry_safe(c, cn, &d->slave.channels,
229 vc.chan.device_node) {
230 spin_lock_irqsave(&c->vc.lock, flags);
231 p = c->phy;
232 if (p && p->ds_done && zx_dma_start_txd(c)) {
233 /* No current txd associated with this channel */
234 dev_dbg(d->slave.dev, "pchan %u: free\n", p->idx);
235 /* Mark this channel free */
236 c->phy = NULL;
237 p->vchan = NULL;
238 }
239 spin_unlock_irqrestore(&c->vc.lock, flags);
240 }
241
242 /* check new channel request in d->chan_pending */
243 spin_lock_irqsave(&d->lock, flags);
244 while (!list_empty(&d->chan_pending)) {
245 c = list_first_entry(&d->chan_pending,
246 struct zx_dma_chan, node);
247 p = &d->phy[c->id];
248 if (!p->vchan) {
249 /* remove from d->chan_pending */
250 list_del_init(&c->node);
251 pch_alloc |= 1 << c->id;
252 /* Mark this channel allocated */
253 p->vchan = c;
254 c->phy = p;
255 } else {
256 dev_dbg(d->slave.dev, "pchan %u: busy!\n", c->id);
257 }
258 }
259 spin_unlock_irqrestore(&d->lock, flags);
260
261 for (pch = 0; pch < d->dma_channels; pch++) {
262 if (pch_alloc & (1 << pch)) {
263 p = &d->phy[pch];
264 c = p->vchan;
265 if (c) {
266 spin_lock_irqsave(&c->vc.lock, flags);
267 zx_dma_start_txd(c);
268 spin_unlock_irqrestore(&c->vc.lock, flags);
269 }
270 }
271 }
272 }
273
274 static irqreturn_t zx_dma_int_handler(int irq, void *dev_id)
275 {
276 struct zx_dma_dev *d = (struct zx_dma_dev *)dev_id;
277 struct zx_dma_phy *p;
278 struct zx_dma_chan *c;
279 u32 tc = readl_relaxed(d->base + REG_ZX_TC_IRQ);
280 u32 serr = readl_relaxed(d->base + REG_ZX_SRC_ERR_IRQ);
281 u32 derr = readl_relaxed(d->base + REG_ZX_DST_ERR_IRQ);
282 u32 cfg = readl_relaxed(d->base + REG_ZX_CFG_ERR_IRQ);
283 u32 i, irq_chan = 0, task = 0;
284
285 while (tc) {
286 i = __ffs(tc);
287 tc &= ~BIT(i);
288 p = &d->phy[i];
289 c = p->vchan;
290 if (c) {
291 unsigned long flags;
292
293 spin_lock_irqsave(&c->vc.lock, flags);
294 if (c->cyclic) {
295 vchan_cyclic_callback(&p->ds_run->vd);
296 } else {
297 vchan_cookie_complete(&p->ds_run->vd);
298 p->ds_done = p->ds_run;
299 task = 1;
300 }
301 spin_unlock_irqrestore(&c->vc.lock, flags);
302 irq_chan |= BIT(i);
303 }
304 }
305
306 if (serr || derr || cfg)
307 dev_warn(d->slave.dev, "DMA ERR src 0x%x, dst 0x%x, cfg 0x%x\n",
308 serr, derr, cfg);
309
310 writel_relaxed(irq_chan, d->base + REG_ZX_TC_IRQ_RAW);
311 writel_relaxed(serr, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
312 writel_relaxed(derr, d->base + REG_ZX_DST_ERR_IRQ_RAW);
313 writel_relaxed(cfg, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
314
315 if (task)
316 zx_dma_task(d);
317 return IRQ_HANDLED;
318 }
319
320 static void zx_dma_free_chan_resources(struct dma_chan *chan)
321 {
322 struct zx_dma_chan *c = to_zx_chan(chan);
323 struct zx_dma_dev *d = to_zx_dma(chan->device);
324 unsigned long flags;
325
326 spin_lock_irqsave(&d->lock, flags);
327 list_del_init(&c->node);
328 spin_unlock_irqrestore(&d->lock, flags);
329
330 vchan_free_chan_resources(&c->vc);
331 c->ccfg = 0;
332 }
333
334 static enum dma_status zx_dma_tx_status(struct dma_chan *chan,
335 dma_cookie_t cookie,
336 struct dma_tx_state *state)
337 {
338 struct zx_dma_chan *c = to_zx_chan(chan);
339 struct zx_dma_phy *p;
340 struct virt_dma_desc *vd;
341 unsigned long flags;
342 enum dma_status ret;
343 size_t bytes = 0;
344
345 ret = dma_cookie_status(&c->vc.chan, cookie, state);
346 if (ret == DMA_COMPLETE || !state)
347 return ret;
348
349 spin_lock_irqsave(&c->vc.lock, flags);
350 p = c->phy;
351 ret = c->status;
352
353 /*
354 * If the cookie is on our issue queue, then the residue is
355 * its total size.
356 */
357 vd = vchan_find_desc(&c->vc, cookie);
358 if (vd) {
359 bytes = container_of(vd, struct zx_dma_desc_sw, vd)->size;
360 } else if ((!p) || (!p->ds_run)) {
361 bytes = 0;
362 } else {
363 struct zx_dma_desc_sw *ds = p->ds_run;
364 u32 clli = 0, index = 0;
365
366 bytes = 0;
367 clli = zx_dma_get_curr_lli(p);
368 index = (clli - ds->desc_hw_lli) / sizeof(struct zx_desc_hw);
369 for (; index < ds->desc_num; index++) {
370 bytes += ds->desc_hw[index].src_x;
371 /* end of lli */
372 if (!ds->desc_hw[index].lli)
373 break;
374 }
375 }
376 spin_unlock_irqrestore(&c->vc.lock, flags);
377 dma_set_residue(state, bytes);
378 return ret;
379 }
380
381 static void zx_dma_issue_pending(struct dma_chan *chan)
382 {
383 struct zx_dma_chan *c = to_zx_chan(chan);
384 struct zx_dma_dev *d = to_zx_dma(chan->device);
385 unsigned long flags;
386 int issue = 0;
387
388 spin_lock_irqsave(&c->vc.lock, flags);
389 /* add request to vc->desc_issued */
390 if (vchan_issue_pending(&c->vc)) {
391 spin_lock(&d->lock);
392 if (!c->phy && list_empty(&c->node)) {
393 /* if new channel, add chan_pending */
394 list_add_tail(&c->node, &d->chan_pending);
395 issue = 1;
396 dev_dbg(d->slave.dev, "vchan %p: issued\n", &c->vc);
397 }
398 spin_unlock(&d->lock);
399 } else {
400 dev_dbg(d->slave.dev, "vchan %p: nothing to issue\n", &c->vc);
401 }
402 spin_unlock_irqrestore(&c->vc.lock, flags);
403
404 if (issue)
405 zx_dma_task(d);
406 }
407
408 static void zx_dma_fill_desc(struct zx_dma_desc_sw *ds, dma_addr_t dst,
409 dma_addr_t src, size_t len, u32 num, u32 ccfg)
410 {
411 if ((num + 1) < ds->desc_num)
412 ds->desc_hw[num].lli = ds->desc_hw_lli + (num + 1) *
413 sizeof(struct zx_desc_hw);
414 ds->desc_hw[num].saddr = src;
415 ds->desc_hw[num].daddr = dst;
416 ds->desc_hw[num].src_x = len;
417 ds->desc_hw[num].ctr = ccfg;
418 }
419
420 static struct zx_dma_desc_sw *zx_alloc_desc_resource(int num,
421 struct dma_chan *chan)
422 {
423 struct zx_dma_chan *c = to_zx_chan(chan);
424 struct zx_dma_desc_sw *ds;
425 struct zx_dma_dev *d = to_zx_dma(chan->device);
426 int lli_limit = LLI_BLOCK_SIZE / sizeof(struct zx_desc_hw);
427
428 if (num > lli_limit) {
429 dev_dbg(chan->device->dev, "vch %p: sg num %d exceed max %d\n",
430 &c->vc, num, lli_limit);
431 return NULL;
432 }
433
434 ds = kzalloc(sizeof(*ds), GFP_ATOMIC);
435 if (!ds)
436 return NULL;
437
438 ds->desc_hw = dma_pool_alloc(d->pool, GFP_NOWAIT, &ds->desc_hw_lli);
439 if (!ds->desc_hw) {
440 dev_dbg(chan->device->dev, "vch %p: dma alloc fail\n", &c->vc);
441 kfree(ds);
442 return NULL;
443 }
444 memset(ds->desc_hw, 0, sizeof(struct zx_desc_hw) * num);
445 ds->desc_num = num;
446 return ds;
447 }
448
449 static enum zx_dma_burst_width zx_dma_burst_width(enum dma_slave_buswidth width)
450 {
451 switch (width) {
452 case DMA_SLAVE_BUSWIDTH_1_BYTE:
453 case DMA_SLAVE_BUSWIDTH_2_BYTES:
454 case DMA_SLAVE_BUSWIDTH_4_BYTES:
455 case DMA_SLAVE_BUSWIDTH_8_BYTES:
456 return ffs(width) - 1;
457 default:
458 return ZX_DMA_WIDTH_32BIT;
459 }
460 }
461
462 static int zx_pre_config(struct zx_dma_chan *c, enum dma_transfer_direction dir)
463 {
464 struct dma_slave_config *cfg = &c->slave_cfg;
465 enum zx_dma_burst_width src_width;
466 enum zx_dma_burst_width dst_width;
467 u32 maxburst = 0;
468
469 switch (dir) {
470 case DMA_MEM_TO_MEM:
471 c->ccfg = ZX_CH_ENABLE | ZX_SOFT_REQ
472 | ZX_SRC_BURST_LEN(ZX_MAX_BURST_LEN - 1)
473 | ZX_SRC_BURST_WIDTH(ZX_DMA_WIDTH_32BIT)
474 | ZX_DST_BURST_WIDTH(ZX_DMA_WIDTH_32BIT);
475 break;
476 case DMA_MEM_TO_DEV:
477 c->dev_addr = cfg->dst_addr;
478 /* dst len is calculated from src width, len and dst width.
479 * We need make sure dst len not exceed MAX LEN.
480 * Trailing single transaction that does not fill a full
481 * burst also require identical src/dst data width.
482 */
483 dst_width = zx_dma_burst_width(cfg->dst_addr_width);
484 maxburst = cfg->dst_maxburst;
485 maxburst = maxburst < ZX_MAX_BURST_LEN ?
486 maxburst : ZX_MAX_BURST_LEN;
487 c->ccfg = ZX_DST_FIFO_MODE | ZX_CH_ENABLE
488 | ZX_SRC_BURST_LEN(maxburst - 1)
489 | ZX_SRC_BURST_WIDTH(dst_width)
490 | ZX_DST_BURST_WIDTH(dst_width);
491 break;
492 case DMA_DEV_TO_MEM:
493 c->dev_addr = cfg->src_addr;
494 src_width = zx_dma_burst_width(cfg->src_addr_width);
495 maxburst = cfg->src_maxburst;
496 maxburst = maxburst < ZX_MAX_BURST_LEN ?
497 maxburst : ZX_MAX_BURST_LEN;
498 c->ccfg = ZX_SRC_FIFO_MODE | ZX_CH_ENABLE
499 | ZX_SRC_BURST_LEN(maxburst - 1)
500 | ZX_SRC_BURST_WIDTH(src_width)
501 | ZX_DST_BURST_WIDTH(src_width);
502 break;
503 default:
504 return -EINVAL;
505 }
506 return 0;
507 }
508
509 static struct dma_async_tx_descriptor *zx_dma_prep_memcpy(
510 struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
511 size_t len, unsigned long flags)
512 {
513 struct zx_dma_chan *c = to_zx_chan(chan);
514 struct zx_dma_desc_sw *ds;
515 size_t copy = 0;
516 int num = 0;
517
518 if (!len)
519 return NULL;
520
521 if (zx_pre_config(c, DMA_MEM_TO_MEM))
522 return NULL;
523
524 num = DIV_ROUND_UP(len, DMA_MAX_SIZE);
525
526 ds = zx_alloc_desc_resource(num, chan);
527 if (!ds)
528 return NULL;
529
530 ds->size = len;
531 num = 0;
532
533 do {
534 copy = min_t(size_t, len, DMA_MAX_SIZE);
535 zx_dma_fill_desc(ds, dst, src, copy, num++, c->ccfg);
536
537 src += copy;
538 dst += copy;
539 len -= copy;
540 } while (len);
541
542 c->cyclic = 0;
543 ds->desc_hw[num - 1].lli = 0; /* end of link */
544 ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
545 return vchan_tx_prep(&c->vc, &ds->vd, flags);
546 }
547
548 static struct dma_async_tx_descriptor *zx_dma_prep_slave_sg(
549 struct dma_chan *chan, struct scatterlist *sgl, unsigned int sglen,
550 enum dma_transfer_direction dir, unsigned long flags, void *context)
551 {
552 struct zx_dma_chan *c = to_zx_chan(chan);
553 struct zx_dma_desc_sw *ds;
554 size_t len, avail, total = 0;
555 struct scatterlist *sg;
556 dma_addr_t addr, src = 0, dst = 0;
557 int num = sglen, i;
558
559 if (!sgl)
560 return NULL;
561
562 if (zx_pre_config(c, dir))
563 return NULL;
564
565 for_each_sg(sgl, sg, sglen, i) {
566 avail = sg_dma_len(sg);
567 if (avail > DMA_MAX_SIZE)
568 num += DIV_ROUND_UP(avail, DMA_MAX_SIZE) - 1;
569 }
570
571 ds = zx_alloc_desc_resource(num, chan);
572 if (!ds)
573 return NULL;
574
575 c->cyclic = 0;
576 num = 0;
577 for_each_sg(sgl, sg, sglen, i) {
578 addr = sg_dma_address(sg);
579 avail = sg_dma_len(sg);
580 total += avail;
581
582 do {
583 len = min_t(size_t, avail, DMA_MAX_SIZE);
584
585 if (dir == DMA_MEM_TO_DEV) {
586 src = addr;
587 dst = c->dev_addr;
588 } else if (dir == DMA_DEV_TO_MEM) {
589 src = c->dev_addr;
590 dst = addr;
591 }
592
593 zx_dma_fill_desc(ds, dst, src, len, num++, c->ccfg);
594
595 addr += len;
596 avail -= len;
597 } while (avail);
598 }
599
600 ds->desc_hw[num - 1].lli = 0; /* end of link */
601 ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
602 ds->size = total;
603 return vchan_tx_prep(&c->vc, &ds->vd, flags);
604 }
605
606 static struct dma_async_tx_descriptor *zx_dma_prep_dma_cyclic(
607 struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
608 size_t period_len, enum dma_transfer_direction dir,
609 unsigned long flags)
610 {
611 struct zx_dma_chan *c = to_zx_chan(chan);
612 struct zx_dma_desc_sw *ds;
613 dma_addr_t src = 0, dst = 0;
614 int num_periods = buf_len / period_len;
615 int buf = 0, num = 0;
616
617 if (period_len > DMA_MAX_SIZE) {
618 dev_err(chan->device->dev, "maximum period size exceeded\n");
619 return NULL;
620 }
621
622 if (zx_pre_config(c, dir))
623 return NULL;
624
625 ds = zx_alloc_desc_resource(num_periods, chan);
626 if (!ds)
627 return NULL;
628 c->cyclic = 1;
629
630 while (buf < buf_len) {
631 if (dir == DMA_MEM_TO_DEV) {
632 src = dma_addr;
633 dst = c->dev_addr;
634 } else if (dir == DMA_DEV_TO_MEM) {
635 src = c->dev_addr;
636 dst = dma_addr;
637 }
638 zx_dma_fill_desc(ds, dst, src, period_len, num++,
639 c->ccfg | ZX_IRQ_ENABLE_ALL);
640 dma_addr += period_len;
641 buf += period_len;
642 }
643
644 ds->desc_hw[num - 1].lli = ds->desc_hw_lli;
645 ds->size = buf_len;
646 return vchan_tx_prep(&c->vc, &ds->vd, flags);
647 }
648
649 static int zx_dma_config(struct dma_chan *chan,
650 struct dma_slave_config *cfg)
651 {
652 struct zx_dma_chan *c = to_zx_chan(chan);
653
654 if (!cfg)
655 return -EINVAL;
656
657 memcpy(&c->slave_cfg, cfg, sizeof(*cfg));
658
659 return 0;
660 }
661
662 static int zx_dma_terminate_all(struct dma_chan *chan)
663 {
664 struct zx_dma_chan *c = to_zx_chan(chan);
665 struct zx_dma_dev *d = to_zx_dma(chan->device);
666 struct zx_dma_phy *p = c->phy;
667 unsigned long flags;
668 LIST_HEAD(head);
669
670 dev_dbg(d->slave.dev, "vchan %p: terminate all\n", &c->vc);
671
672 /* Prevent this channel being scheduled */
673 spin_lock(&d->lock);
674 list_del_init(&c->node);
675 spin_unlock(&d->lock);
676
677 /* Clear the tx descriptor lists */
678 spin_lock_irqsave(&c->vc.lock, flags);
679 vchan_get_all_descriptors(&c->vc, &head);
680 if (p) {
681 /* vchan is assigned to a pchan - stop the channel */
682 zx_dma_terminate_chan(p, d);
683 c->phy = NULL;
684 p->vchan = NULL;
685 p->ds_run = NULL;
686 p->ds_done = NULL;
687 }
688 spin_unlock_irqrestore(&c->vc.lock, flags);
689 vchan_dma_desc_free_list(&c->vc, &head);
690
691 return 0;
692 }
693
694 static int zx_dma_transfer_pause(struct dma_chan *chan)
695 {
696 struct zx_dma_chan *c = to_zx_chan(chan);
697 u32 val = 0;
698
699 val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
700 val &= ~ZX_CH_ENABLE;
701 writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
702
703 return 0;
704 }
705
706 static int zx_dma_transfer_resume(struct dma_chan *chan)
707 {
708 struct zx_dma_chan *c = to_zx_chan(chan);
709 u32 val = 0;
710
711 val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
712 val |= ZX_CH_ENABLE;
713 writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
714
715 return 0;
716 }
717
718 static void zx_dma_free_desc(struct virt_dma_desc *vd)
719 {
720 struct zx_dma_desc_sw *ds =
721 container_of(vd, struct zx_dma_desc_sw, vd);
722 struct zx_dma_dev *d = to_zx_dma(vd->tx.chan->device);
723
724 dma_pool_free(d->pool, ds->desc_hw, ds->desc_hw_lli);
725 kfree(ds);
726 }
727
728 static const struct of_device_id zx6702_dma_dt_ids[] = {
729 { .compatible = "zte,zx296702-dma", },
730 {}
731 };
732 MODULE_DEVICE_TABLE(of, zx6702_dma_dt_ids);
733
734 static struct dma_chan *zx_of_dma_simple_xlate(struct of_phandle_args *dma_spec,
735 struct of_dma *ofdma)
736 {
737 struct zx_dma_dev *d = ofdma->of_dma_data;
738 unsigned int request = dma_spec->args[0];
739 struct dma_chan *chan;
740 struct zx_dma_chan *c;
741
742 if (request >= d->dma_requests)
743 return NULL;
744
745 chan = dma_get_any_slave_channel(&d->slave);
746 if (!chan) {
747 dev_err(d->slave.dev, "get channel fail in %s.\n", __func__);
748 return NULL;
749 }
750 c = to_zx_chan(chan);
751 c->id = request;
752 dev_info(d->slave.dev, "zx_dma: pchan %u: alloc vchan %p\n",
753 c->id, &c->vc);
754 return chan;
755 }
756
757 static int zx_dma_probe(struct platform_device *op)
758 {
759 struct zx_dma_dev *d;
760 struct resource *iores;
761 int i, ret = 0;
762
763 iores = platform_get_resource(op, IORESOURCE_MEM, 0);
764 if (!iores)
765 return -EINVAL;
766
767 d = devm_kzalloc(&op->dev, sizeof(*d), GFP_KERNEL);
768 if (!d)
769 return -ENOMEM;
770
771 d->base = devm_ioremap_resource(&op->dev, iores);
772 if (IS_ERR(d->base))
773 return PTR_ERR(d->base);
774
775 of_property_read_u32((&op->dev)->of_node,
776 "dma-channels", &d->dma_channels);
777 of_property_read_u32((&op->dev)->of_node,
778 "dma-requests", &d->dma_requests);
779 if (!d->dma_requests || !d->dma_channels)
780 return -EINVAL;
781
782 d->clk = devm_clk_get(&op->dev, NULL);
783 if (IS_ERR(d->clk)) {
784 dev_err(&op->dev, "no dma clk\n");
785 return PTR_ERR(d->clk);
786 }
787
788 d->irq = platform_get_irq(op, 0);
789 ret = devm_request_irq(&op->dev, d->irq, zx_dma_int_handler,
790 0, DRIVER_NAME, d);
791 if (ret)
792 return ret;
793
794 /* A DMA memory pool for LLIs, align on 32-byte boundary */
795 d->pool = dmam_pool_create(DRIVER_NAME, &op->dev,
796 LLI_BLOCK_SIZE, 32, 0);
797 if (!d->pool)
798 return -ENOMEM;
799
800 /* init phy channel */
801 d->phy = devm_kzalloc(&op->dev,
802 d->dma_channels * sizeof(struct zx_dma_phy), GFP_KERNEL);
803 if (!d->phy)
804 return -ENOMEM;
805
806 for (i = 0; i < d->dma_channels; i++) {
807 struct zx_dma_phy *p = &d->phy[i];
808
809 p->idx = i;
810 p->base = d->base + i * 0x40;
811 }
812
813 INIT_LIST_HEAD(&d->slave.channels);
814 dma_cap_set(DMA_SLAVE, d->slave.cap_mask);
815 dma_cap_set(DMA_MEMCPY, d->slave.cap_mask);
816 dma_cap_set(DMA_CYCLIC, d->slave.cap_mask);
817 dma_cap_set(DMA_PRIVATE, d->slave.cap_mask);
818 d->slave.dev = &op->dev;
819 d->slave.device_free_chan_resources = zx_dma_free_chan_resources;
820 d->slave.device_tx_status = zx_dma_tx_status;
821 d->slave.device_prep_dma_memcpy = zx_dma_prep_memcpy;
822 d->slave.device_prep_slave_sg = zx_dma_prep_slave_sg;
823 d->slave.device_prep_dma_cyclic = zx_dma_prep_dma_cyclic;
824 d->slave.device_issue_pending = zx_dma_issue_pending;
825 d->slave.device_config = zx_dma_config;
826 d->slave.device_terminate_all = zx_dma_terminate_all;
827 d->slave.device_pause = zx_dma_transfer_pause;
828 d->slave.device_resume = zx_dma_transfer_resume;
829 d->slave.copy_align = DMA_ALIGN;
830 d->slave.src_addr_widths = ZX_DMA_BUSWIDTHS;
831 d->slave.dst_addr_widths = ZX_DMA_BUSWIDTHS;
832 d->slave.directions = BIT(DMA_MEM_TO_MEM) | BIT(DMA_MEM_TO_DEV)
833 | BIT(DMA_DEV_TO_MEM);
834 d->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
835
836 /* init virtual channel */
837 d->chans = devm_kzalloc(&op->dev,
838 d->dma_requests * sizeof(struct zx_dma_chan), GFP_KERNEL);
839 if (!d->chans)
840 return -ENOMEM;
841
842 for (i = 0; i < d->dma_requests; i++) {
843 struct zx_dma_chan *c = &d->chans[i];
844
845 c->status = DMA_IN_PROGRESS;
846 INIT_LIST_HEAD(&c->node);
847 c->vc.desc_free = zx_dma_free_desc;
848 vchan_init(&c->vc, &d->slave);
849 }
850
851 /* Enable clock before accessing registers */
852 ret = clk_prepare_enable(d->clk);
853 if (ret < 0) {
854 dev_err(&op->dev, "clk_prepare_enable failed: %d\n", ret);
855 goto zx_dma_out;
856 }
857
858 zx_dma_init_state(d);
859
860 spin_lock_init(&d->lock);
861 INIT_LIST_HEAD(&d->chan_pending);
862 platform_set_drvdata(op, d);
863
864 ret = dma_async_device_register(&d->slave);
865 if (ret)
866 goto clk_dis;
867
868 ret = of_dma_controller_register((&op->dev)->of_node,
869 zx_of_dma_simple_xlate, d);
870 if (ret)
871 goto of_dma_register_fail;
872
873 dev_info(&op->dev, "initialized\n");
874 return 0;
875
876 of_dma_register_fail:
877 dma_async_device_unregister(&d->slave);
878 clk_dis:
879 clk_disable_unprepare(d->clk);
880 zx_dma_out:
881 return ret;
882 }
883
884 static int zx_dma_remove(struct platform_device *op)
885 {
886 struct zx_dma_chan *c, *cn;
887 struct zx_dma_dev *d = platform_get_drvdata(op);
888
889 /* explictly free the irq */
890 devm_free_irq(&op->dev, d->irq, d);
891
892 dma_async_device_unregister(&d->slave);
893 of_dma_controller_free((&op->dev)->of_node);
894
895 list_for_each_entry_safe(c, cn, &d->slave.channels,
896 vc.chan.device_node) {
897 list_del(&c->vc.chan.device_node);
898 }
899 clk_disable_unprepare(d->clk);
900 dmam_pool_destroy(d->pool);
901
902 return 0;
903 }
904
905 #ifdef CONFIG_PM_SLEEP
906 static int zx_dma_suspend_dev(struct device *dev)
907 {
908 struct zx_dma_dev *d = dev_get_drvdata(dev);
909 u32 stat = 0;
910
911 stat = zx_dma_get_chan_stat(d);
912 if (stat) {
913 dev_warn(d->slave.dev,
914 "chan %d is running fail to suspend\n", stat);
915 return -1;
916 }
917 clk_disable_unprepare(d->clk);
918 return 0;
919 }
920
921 static int zx_dma_resume_dev(struct device *dev)
922 {
923 struct zx_dma_dev *d = dev_get_drvdata(dev);
924 int ret = 0;
925
926 ret = clk_prepare_enable(d->clk);
927 if (ret < 0) {
928 dev_err(d->slave.dev, "clk_prepare_enable failed: %d\n", ret);
929 return ret;
930 }
931 zx_dma_init_state(d);
932 return 0;
933 }
934 #endif
935
936 static SIMPLE_DEV_PM_OPS(zx_dma_pmops, zx_dma_suspend_dev, zx_dma_resume_dev);
937
938 static struct platform_driver zx_pdma_driver = {
939 .driver = {
940 .name = DRIVER_NAME,
941 .pm = &zx_dma_pmops,
942 .of_match_table = zx6702_dma_dt_ids,
943 },
944 .probe = zx_dma_probe,
945 .remove = zx_dma_remove,
946 };
947
948 module_platform_driver(zx_pdma_driver);
949
950 MODULE_DESCRIPTION("ZTE ZX296702 DMA Driver");
951 MODULE_AUTHOR("Jun Nie jun.nie@linaro.org");
952 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support