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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * S3C24XX DMA handling
4 *
5 * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>
6 *
7 * based on amba-pl08x.c
8 *
9 * Copyright (c) 2006 ARM Ltd.
10 * Copyright (c) 2010 ST-Ericsson SA
11 *
12 * Author: Peter Pearse <peter.pearse@arm.com>
13 * Author: Linus Walleij <linus.walleij@stericsson.com>
14 *
15 * The DMA controllers in S3C24XX SoCs have a varying number of DMA signals
16 * that can be routed to any of the 4 to 8 hardware-channels.
17 *
18 * Therefore on these DMA controllers the number of channels
19 * and the number of incoming DMA signals are two totally different things.
20 * It is usually not possible to theoretically handle all physical signals,
21 * so a multiplexing scheme with possible denial of use is necessary.
22 *
23 * Open items:
24 * - bursts
25 */
26
27#include <linux/platform_device.h>
28#include <linux/types.h>
29#include <linux/dmaengine.h>
30#include <linux/dma-mapping.h>
31#include <linux/interrupt.h>
32#include <linux/clk.h>
33#include <linux/module.h>
34#include <linux/mod_devicetable.h>
35#include <linux/slab.h>
36#include <linux/platform_data/dma-s3c24xx.h>
37
38#include "dmaengine.h"
39#include "virt-dma.h"
40
41#define MAX_DMA_CHANNELS 8
42
43#define S3C24XX_DISRC 0x00
44#define S3C24XX_DISRCC 0x04
45#define S3C24XX_DISRCC_INC_INCREMENT 0
46#define S3C24XX_DISRCC_INC_FIXED BIT(0)
47#define S3C24XX_DISRCC_LOC_AHB 0
48#define S3C24XX_DISRCC_LOC_APB BIT(1)
49
50#define S3C24XX_DIDST 0x08
51#define S3C24XX_DIDSTC 0x0c
52#define S3C24XX_DIDSTC_INC_INCREMENT 0
53#define S3C24XX_DIDSTC_INC_FIXED BIT(0)
54#define S3C24XX_DIDSTC_LOC_AHB 0
55#define S3C24XX_DIDSTC_LOC_APB BIT(1)
56#define S3C24XX_DIDSTC_INT_TC0 0
57#define S3C24XX_DIDSTC_INT_RELOAD BIT(2)
58
59#define S3C24XX_DCON 0x10
60
61#define S3C24XX_DCON_TC_MASK 0xfffff
62#define S3C24XX_DCON_DSZ_BYTE (0 << 20)
63#define S3C24XX_DCON_DSZ_HALFWORD (1 << 20)
64#define S3C24XX_DCON_DSZ_WORD (2 << 20)
65#define S3C24XX_DCON_DSZ_MASK (3 << 20)
66#define S3C24XX_DCON_DSZ_SHIFT 20
67#define S3C24XX_DCON_AUTORELOAD 0
68#define S3C24XX_DCON_NORELOAD BIT(22)
69#define S3C24XX_DCON_HWTRIG BIT(23)
70#define S3C24XX_DCON_HWSRC_SHIFT 24
71#define S3C24XX_DCON_SERV_SINGLE 0
72#define S3C24XX_DCON_SERV_WHOLE BIT(27)
73#define S3C24XX_DCON_TSZ_UNIT 0
74#define S3C24XX_DCON_TSZ_BURST4 BIT(28)
75#define S3C24XX_DCON_INT BIT(29)
76#define S3C24XX_DCON_SYNC_PCLK 0
77#define S3C24XX_DCON_SYNC_HCLK BIT(30)
78#define S3C24XX_DCON_DEMAND 0
79#define S3C24XX_DCON_HANDSHAKE BIT(31)
80
81#define S3C24XX_DSTAT 0x14
82#define S3C24XX_DSTAT_STAT_BUSY BIT(20)
83#define S3C24XX_DSTAT_CURRTC_MASK 0xfffff
84
85#define S3C24XX_DMASKTRIG 0x20
86#define S3C24XX_DMASKTRIG_SWTRIG BIT(0)
87#define S3C24XX_DMASKTRIG_ON BIT(1)
88#define S3C24XX_DMASKTRIG_STOP BIT(2)
89
90#define S3C24XX_DMAREQSEL 0x24
91#define S3C24XX_DMAREQSEL_HW BIT(0)
92
93/*
94 * S3C2410, S3C2440 and S3C2442 SoCs cannot select any physical channel
95 * for a DMA source. Instead only specific channels are valid.
96 * All of these SoCs have 4 physical channels and the number of request
97 * source bits is 3. Additionally we also need 1 bit to mark the channel
98 * as valid.
99 * Therefore we separate the chansel element of the channel data into 4
100 * parts of 4 bits each, to hold the information if the channel is valid
101 * and the hw request source to use.
102 *
103 * Example:
104 * SDI is valid on channels 0, 2 and 3 - with varying hw request sources.
105 * For it the chansel field would look like
106 *
107 * ((BIT(3) | 1) << 3 * 4) | // channel 3, with request source 1
108 * ((BIT(3) | 2) << 2 * 4) | // channel 2, with request source 2
109 * ((BIT(3) | 2) << 0 * 4) // channel 0, with request source 2
110 */
111#define S3C24XX_CHANSEL_WIDTH 4
112#define S3C24XX_CHANSEL_VALID BIT(3)
113#define S3C24XX_CHANSEL_REQ_MASK 7
114
115/*
116 * struct soc_data - vendor-specific config parameters for individual SoCs
117 * @stride: spacing between the registers of each channel
118 * @has_reqsel: does the controller use the newer requestselection mechanism
119 * @has_clocks: are controllable dma-clocks present
120 */
121struct soc_data {
122 int stride;
123 bool has_reqsel;
124 bool has_clocks;
125};
126
127/*
128 * enum s3c24xx_dma_chan_state - holds the virtual channel states
129 * @S3C24XX_DMA_CHAN_IDLE: the channel is idle
130 * @S3C24XX_DMA_CHAN_RUNNING: the channel has allocated a physical transport
131 * channel and is running a transfer on it
132 * @S3C24XX_DMA_CHAN_WAITING: the channel is waiting for a physical transport
133 * channel to become available (only pertains to memcpy channels)
134 */
135enum s3c24xx_dma_chan_state {
136 S3C24XX_DMA_CHAN_IDLE,
137 S3C24XX_DMA_CHAN_RUNNING,
138 S3C24XX_DMA_CHAN_WAITING,
139};
140
141/*
142 * struct s3c24xx_sg - structure containing data per sg
143 * @src_addr: src address of sg
144 * @dst_addr: dst address of sg
145 * @len: transfer len in bytes
146 * @node: node for txd's dsg_list
147 */
148struct s3c24xx_sg {
149 dma_addr_t src_addr;
150 dma_addr_t dst_addr;
151 size_t len;
152 struct list_head node;
153};
154
155/*
156 * struct s3c24xx_txd - wrapper for struct dma_async_tx_descriptor
157 * @vd: virtual DMA descriptor
158 * @dsg_list: list of children sg's
159 * @at: sg currently being transfered
160 * @width: transfer width
161 * @disrcc: value for source control register
162 * @didstc: value for destination control register
163 * @dcon: base value for dcon register
164 * @cyclic: indicate cyclic transfer
165 */
166struct s3c24xx_txd {
167 struct virt_dma_desc vd;
168 struct list_head dsg_list;
169 struct list_head *at;
170 u8 width;
171 u32 disrcc;
172 u32 didstc;
173 u32 dcon;
174 bool cyclic;
175};
176
177struct s3c24xx_dma_chan;
178
179/*
180 * struct s3c24xx_dma_phy - holder for the physical channels
181 * @id: physical index to this channel
182 * @valid: does the channel have all required elements
183 * @base: virtual memory base (remapped) for the this channel
184 * @irq: interrupt for this channel
185 * @clk: clock for this channel
186 * @lock: a lock to use when altering an instance of this struct
187 * @serving: virtual channel currently being served by this physicalchannel
188 * @host: a pointer to the host (internal use)
189 */
190struct s3c24xx_dma_phy {
191 unsigned int id;
192 bool valid;
193 void __iomem *base;
194 int irq;
195 struct clk *clk;
196 spinlock_t lock;
197 struct s3c24xx_dma_chan *serving;
198 struct s3c24xx_dma_engine *host;
199};
200
201/*
202 * struct s3c24xx_dma_chan - this structure wraps a DMA ENGINE channel
203 * @id: the id of the channel
204 * @name: name of the channel
205 * @vc: wrappped virtual channel
206 * @phy: the physical channel utilized by this channel, if there is one
207 * @runtime_addr: address for RX/TX according to the runtime config
208 * @at: active transaction on this channel
209 * @lock: a lock for this channel data
210 * @host: a pointer to the host (internal use)
211 * @state: whether the channel is idle, running etc
212 * @slave: whether this channel is a device (slave) or for memcpy
213 */
214struct s3c24xx_dma_chan {
215 int id;
216 const char *name;
217 struct virt_dma_chan vc;
218 struct s3c24xx_dma_phy *phy;
219 struct dma_slave_config cfg;
220 struct s3c24xx_txd *at;
221 struct s3c24xx_dma_engine *host;
222 enum s3c24xx_dma_chan_state state;
223 bool slave;
224};
225
226/*
227 * struct s3c24xx_dma_engine - the local state holder for the S3C24XX
228 * @pdev: the corresponding platform device
229 * @pdata: platform data passed in from the platform/machine
230 * @base: virtual memory base (remapped)
231 * @slave: slave engine for this instance
232 * @memcpy: memcpy engine for this instance
233 * @phy_chans: array of data for the physical channels
234 */
235struct s3c24xx_dma_engine {
236 struct platform_device *pdev;
237 const struct s3c24xx_dma_platdata *pdata;
238 struct soc_data *sdata;
239 void __iomem *base;
240 struct dma_device slave;
241 struct dma_device memcpy;
242 struct s3c24xx_dma_phy *phy_chans;
243};
244
245/*
246 * Physical channel handling
247 */
248
249/*
250 * Check whether a certain channel is busy or not.
251 */
252static int s3c24xx_dma_phy_busy(struct s3c24xx_dma_phy *phy)
253{
254 unsigned int val = readl(phy->base + S3C24XX_DSTAT);
255 return val & S3C24XX_DSTAT_STAT_BUSY;
256}
257
258static bool s3c24xx_dma_phy_valid(struct s3c24xx_dma_chan *s3cchan,
259 struct s3c24xx_dma_phy *phy)
260{
261 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
262 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
263 struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
264 int phyvalid;
265
266 /* every phy is valid for memcopy channels */
267 if (!s3cchan->slave)
268 return true;
269
270 /* On newer variants all phys can be used for all virtual channels */
271 if (s3cdma->sdata->has_reqsel)
272 return true;
273
274 phyvalid = (cdata->chansel >> (phy->id * S3C24XX_CHANSEL_WIDTH));
275 return (phyvalid & S3C24XX_CHANSEL_VALID) ? true : false;
276}
277
278/*
279 * Allocate a physical channel for a virtual channel
280 *
281 * Try to locate a physical channel to be used for this transfer. If all
282 * are taken return NULL and the requester will have to cope by using
283 * some fallback PIO mode or retrying later.
284 */
285static
286struct s3c24xx_dma_phy *s3c24xx_dma_get_phy(struct s3c24xx_dma_chan *s3cchan)
287{
288 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
289 struct s3c24xx_dma_phy *phy = NULL;
290 unsigned long flags;
291 int i;
292 int ret;
293
294 for (i = 0; i < s3cdma->pdata->num_phy_channels; i++) {
295 phy = &s3cdma->phy_chans[i];
296
297 if (!phy->valid)
298 continue;
299
300 if (!s3c24xx_dma_phy_valid(s3cchan, phy))
301 continue;
302
303 spin_lock_irqsave(&phy->lock, flags);
304
305 if (!phy->serving) {
306 phy->serving = s3cchan;
307 spin_unlock_irqrestore(&phy->lock, flags);
308 break;
309 }
310
311 spin_unlock_irqrestore(&phy->lock, flags);
312 }
313
314 /* No physical channel available, cope with it */
315 if (i == s3cdma->pdata->num_phy_channels) {
316 dev_warn(&s3cdma->pdev->dev, "no phy channel available\n");
317 return NULL;
318 }
319
320 /* start the phy clock */
321 if (s3cdma->sdata->has_clocks) {
322 ret = clk_enable(phy->clk);
323 if (ret) {
324 dev_err(&s3cdma->pdev->dev, "could not enable clock for channel %d, err %d\n",
325 phy->id, ret);
326 phy->serving = NULL;
327 return NULL;
328 }
329 }
330
331 return phy;
332}
333
334/*
335 * Mark the physical channel as free.
336 *
337 * This drops the link between the physical and virtual channel.
338 */
339static inline void s3c24xx_dma_put_phy(struct s3c24xx_dma_phy *phy)
340{
341 struct s3c24xx_dma_engine *s3cdma = phy->host;
342
343 if (s3cdma->sdata->has_clocks)
344 clk_disable(phy->clk);
345
346 phy->serving = NULL;
347}
348
349/*
350 * Stops the channel by writing the stop bit.
351 * This should not be used for an on-going transfer, but as a method of
352 * shutting down a channel (eg, when it's no longer used) or terminating a
353 * transfer.
354 */
355static void s3c24xx_dma_terminate_phy(struct s3c24xx_dma_phy *phy)
356{
357 writel(S3C24XX_DMASKTRIG_STOP, phy->base + S3C24XX_DMASKTRIG);
358}
359
360/*
361 * Virtual channel handling
362 */
363
364static inline
365struct s3c24xx_dma_chan *to_s3c24xx_dma_chan(struct dma_chan *chan)
366{
367 return container_of(chan, struct s3c24xx_dma_chan, vc.chan);
368}
369
370static u32 s3c24xx_dma_getbytes_chan(struct s3c24xx_dma_chan *s3cchan)
371{
372 struct s3c24xx_dma_phy *phy = s3cchan->phy;
373 struct s3c24xx_txd *txd = s3cchan->at;
374 u32 tc = readl(phy->base + S3C24XX_DSTAT) & S3C24XX_DSTAT_CURRTC_MASK;
375
376 return tc * txd->width;
377}
378
379static int s3c24xx_dma_set_runtime_config(struct dma_chan *chan,
380 struct dma_slave_config *config)
381{
382 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
383 unsigned long flags;
384 int ret = 0;
385
386 /* Reject definitely invalid configurations */
387 if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
388 config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
389 return -EINVAL;
390
391 spin_lock_irqsave(&s3cchan->vc.lock, flags);
392
393 if (!s3cchan->slave) {
394 ret = -EINVAL;
395 goto out;
396 }
397
398 s3cchan->cfg = *config;
399
400out:
401 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
402 return ret;
403}
404
405/*
406 * Transfer handling
407 */
408
409static inline
410struct s3c24xx_txd *to_s3c24xx_txd(struct dma_async_tx_descriptor *tx)
411{
412 return container_of(tx, struct s3c24xx_txd, vd.tx);
413}
414
415static struct s3c24xx_txd *s3c24xx_dma_get_txd(void)
416{
417 struct s3c24xx_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
418
419 if (txd) {
420 INIT_LIST_HEAD(&txd->dsg_list);
421 txd->dcon = S3C24XX_DCON_INT | S3C24XX_DCON_NORELOAD;
422 }
423
424 return txd;
425}
426
427static void s3c24xx_dma_free_txd(struct s3c24xx_txd *txd)
428{
429 struct s3c24xx_sg *dsg, *_dsg;
430
431 list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {
432 list_del(&dsg->node);
433 kfree(dsg);
434 }
435
436 kfree(txd);
437}
438
439static void s3c24xx_dma_start_next_sg(struct s3c24xx_dma_chan *s3cchan,
440 struct s3c24xx_txd *txd)
441{
442 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
443 struct s3c24xx_dma_phy *phy = s3cchan->phy;
444 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
445 struct s3c24xx_sg *dsg = list_entry(txd->at, struct s3c24xx_sg, node);
446 u32 dcon = txd->dcon;
447 u32 val;
448
449 /* transfer-size and -count from len and width */
450 switch (txd->width) {
451 case 1:
452 dcon |= S3C24XX_DCON_DSZ_BYTE | dsg->len;
453 break;
454 case 2:
455 dcon |= S3C24XX_DCON_DSZ_HALFWORD | (dsg->len / 2);
456 break;
457 case 4:
458 dcon |= S3C24XX_DCON_DSZ_WORD | (dsg->len / 4);
459 break;
460 }
461
462 if (s3cchan->slave) {
463 struct s3c24xx_dma_channel *cdata =
464 &pdata->channels[s3cchan->id];
465
466 if (s3cdma->sdata->has_reqsel) {
467 writel_relaxed((cdata->chansel << 1) |
468 S3C24XX_DMAREQSEL_HW,
469 phy->base + S3C24XX_DMAREQSEL);
470 } else {
471 int csel = cdata->chansel >> (phy->id *
472 S3C24XX_CHANSEL_WIDTH);
473
474 csel &= S3C24XX_CHANSEL_REQ_MASK;
475 dcon |= csel << S3C24XX_DCON_HWSRC_SHIFT;
476 dcon |= S3C24XX_DCON_HWTRIG;
477 }
478 } else {
479 if (s3cdma->sdata->has_reqsel)
480 writel_relaxed(0, phy->base + S3C24XX_DMAREQSEL);
481 }
482
483 writel_relaxed(dsg->src_addr, phy->base + S3C24XX_DISRC);
484 writel_relaxed(txd->disrcc, phy->base + S3C24XX_DISRCC);
485 writel_relaxed(dsg->dst_addr, phy->base + S3C24XX_DIDST);
486 writel_relaxed(txd->didstc, phy->base + S3C24XX_DIDSTC);
487 writel_relaxed(dcon, phy->base + S3C24XX_DCON);
488
489 val = readl_relaxed(phy->base + S3C24XX_DMASKTRIG);
490 val &= ~S3C24XX_DMASKTRIG_STOP;
491 val |= S3C24XX_DMASKTRIG_ON;
492
493 /* trigger the dma operation for memcpy transfers */
494 if (!s3cchan->slave)
495 val |= S3C24XX_DMASKTRIG_SWTRIG;
496
497 writel(val, phy->base + S3C24XX_DMASKTRIG);
498}
499
500/*
501 * Set the initial DMA register values and start first sg.
502 */
503static void s3c24xx_dma_start_next_txd(struct s3c24xx_dma_chan *s3cchan)
504{
505 struct s3c24xx_dma_phy *phy = s3cchan->phy;
506 struct virt_dma_desc *vd = vchan_next_desc(&s3cchan->vc);
507 struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx);
508
509 list_del(&txd->vd.node);
510
511 s3cchan->at = txd;
512
513 /* Wait for channel inactive */
514 while (s3c24xx_dma_phy_busy(phy))
515 cpu_relax();
516
517 /* point to the first element of the sg list */
518 txd->at = txd->dsg_list.next;
519 s3c24xx_dma_start_next_sg(s3cchan, txd);
520}
521
522/*
523 * Try to allocate a physical channel. When successful, assign it to
524 * this virtual channel, and initiate the next descriptor. The
525 * virtual channel lock must be held at this point.
526 */
527static void s3c24xx_dma_phy_alloc_and_start(struct s3c24xx_dma_chan *s3cchan)
528{
529 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
530 struct s3c24xx_dma_phy *phy;
531
532 phy = s3c24xx_dma_get_phy(s3cchan);
533 if (!phy) {
534 dev_dbg(&s3cdma->pdev->dev, "no physical channel available for xfer on %s\n",
535 s3cchan->name);
536 s3cchan->state = S3C24XX_DMA_CHAN_WAITING;
537 return;
538 }
539
540 dev_dbg(&s3cdma->pdev->dev, "allocated physical channel %d for xfer on %s\n",
541 phy->id, s3cchan->name);
542
543 s3cchan->phy = phy;
544 s3cchan->state = S3C24XX_DMA_CHAN_RUNNING;
545
546 s3c24xx_dma_start_next_txd(s3cchan);
547}
548
549static void s3c24xx_dma_phy_reassign_start(struct s3c24xx_dma_phy *phy,
550 struct s3c24xx_dma_chan *s3cchan)
551{
552 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
553
554 dev_dbg(&s3cdma->pdev->dev, "reassigned physical channel %d for xfer on %s\n",
555 phy->id, s3cchan->name);
556
557 /*
558 * We do this without taking the lock; we're really only concerned
559 * about whether this pointer is NULL or not, and we're guaranteed
560 * that this will only be called when it _already_ is non-NULL.
561 */
562 phy->serving = s3cchan;
563 s3cchan->phy = phy;
564 s3cchan->state = S3C24XX_DMA_CHAN_RUNNING;
565 s3c24xx_dma_start_next_txd(s3cchan);
566}
567
568/*
569 * Free a physical DMA channel, potentially reallocating it to another
570 * virtual channel if we have any pending.
571 */
572static void s3c24xx_dma_phy_free(struct s3c24xx_dma_chan *s3cchan)
573{
574 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
575 struct s3c24xx_dma_chan *p, *next;
576
577retry:
578 next = NULL;
579
580 /* Find a waiting virtual channel for the next transfer. */
581 list_for_each_entry(p, &s3cdma->memcpy.channels, vc.chan.device_node)
582 if (p->state == S3C24XX_DMA_CHAN_WAITING) {
583 next = p;
584 break;
585 }
586
587 if (!next) {
588 list_for_each_entry(p, &s3cdma->slave.channels,
589 vc.chan.device_node)
590 if (p->state == S3C24XX_DMA_CHAN_WAITING &&
591 s3c24xx_dma_phy_valid(p, s3cchan->phy)) {
592 next = p;
593 break;
594 }
595 }
596
597 /* Ensure that the physical channel is stopped */
598 s3c24xx_dma_terminate_phy(s3cchan->phy);
599
600 if (next) {
601 bool success;
602
603 /*
604 * Eww. We know this isn't going to deadlock
605 * but lockdep probably doesn't.
606 */
607 spin_lock(&next->vc.lock);
608 /* Re-check the state now that we have the lock */
609 success = next->state == S3C24XX_DMA_CHAN_WAITING;
610 if (success)
611 s3c24xx_dma_phy_reassign_start(s3cchan->phy, next);
612 spin_unlock(&next->vc.lock);
613
614 /* If the state changed, try to find another channel */
615 if (!success)
616 goto retry;
617 } else {
618 /* No more jobs, so free up the physical channel */
619 s3c24xx_dma_put_phy(s3cchan->phy);
620 }
621
622 s3cchan->phy = NULL;
623 s3cchan->state = S3C24XX_DMA_CHAN_IDLE;
624}
625
626static void s3c24xx_dma_desc_free(struct virt_dma_desc *vd)
627{
628 struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx);
629 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(vd->tx.chan);
630
631 if (!s3cchan->slave)
632 dma_descriptor_unmap(&vd->tx);
633
634 s3c24xx_dma_free_txd(txd);
635}
636
637static irqreturn_t s3c24xx_dma_irq(int irq, void *data)
638{
639 struct s3c24xx_dma_phy *phy = data;
640 struct s3c24xx_dma_chan *s3cchan = phy->serving;
641 struct s3c24xx_txd *txd;
642
643 dev_dbg(&phy->host->pdev->dev, "interrupt on channel %d\n", phy->id);
644
645 /*
646 * Interrupts happen to notify the completion of a transfer and the
647 * channel should have moved into its stop state already on its own.
648 * Therefore interrupts on channels not bound to a virtual channel
649 * should never happen. Nevertheless send a terminate command to the
650 * channel if the unlikely case happens.
651 */
652 if (unlikely(!s3cchan)) {
653 dev_err(&phy->host->pdev->dev, "interrupt on unused channel %d\n",
654 phy->id);
655
656 s3c24xx_dma_terminate_phy(phy);
657
658 return IRQ_HANDLED;
659 }
660
661 spin_lock(&s3cchan->vc.lock);
662 txd = s3cchan->at;
663 if (txd) {
664 /* when more sg's are in this txd, start the next one */
665 if (!list_is_last(txd->at, &txd->dsg_list)) {
666 txd->at = txd->at->next;
667 if (txd->cyclic)
668 vchan_cyclic_callback(&txd->vd);
669 s3c24xx_dma_start_next_sg(s3cchan, txd);
670 } else if (!txd->cyclic) {
671 s3cchan->at = NULL;
672 vchan_cookie_complete(&txd->vd);
673
674 /*
675 * And start the next descriptor (if any),
676 * otherwise free this channel.
677 */
678 if (vchan_next_desc(&s3cchan->vc))
679 s3c24xx_dma_start_next_txd(s3cchan);
680 else
681 s3c24xx_dma_phy_free(s3cchan);
682 } else {
683 vchan_cyclic_callback(&txd->vd);
684
685 /* Cyclic: reset at beginning */
686 txd->at = txd->dsg_list.next;
687 s3c24xx_dma_start_next_sg(s3cchan, txd);
688 }
689 }
690 spin_unlock(&s3cchan->vc.lock);
691
692 return IRQ_HANDLED;
693}
694
695/*
696 * The DMA ENGINE API
697 */
698
699static int s3c24xx_dma_terminate_all(struct dma_chan *chan)
700{
701 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
702 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
703 LIST_HEAD(head);
704 unsigned long flags;
705 int ret;
706
707 spin_lock_irqsave(&s3cchan->vc.lock, flags);
708
709 if (!s3cchan->phy && !s3cchan->at) {
710 dev_err(&s3cdma->pdev->dev, "trying to terminate already stopped channel %d\n",
711 s3cchan->id);
712 ret = -EINVAL;
713 goto unlock;
714 }
715
716 s3cchan->state = S3C24XX_DMA_CHAN_IDLE;
717
718 /* Mark physical channel as free */
719 if (s3cchan->phy)
720 s3c24xx_dma_phy_free(s3cchan);
721
722 /* Dequeue current job */
723 if (s3cchan->at) {
724 vchan_terminate_vdesc(&s3cchan->at->vd);
725 s3cchan->at = NULL;
726 }
727
728 /* Dequeue jobs not yet fired as well */
729
730 vchan_get_all_descriptors(&s3cchan->vc, &head);
731
732 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
733
734 vchan_dma_desc_free_list(&s3cchan->vc, &head);
735
736 return 0;
737
738unlock:
739 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
740
741 return ret;
742}
743
744static void s3c24xx_dma_synchronize(struct dma_chan *chan)
745{
746 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
747
748 vchan_synchronize(&s3cchan->vc);
749}
750
751static void s3c24xx_dma_free_chan_resources(struct dma_chan *chan)
752{
753 /* Ensure all queued descriptors are freed */
754 vchan_free_chan_resources(to_virt_chan(chan));
755}
756
757static enum dma_status s3c24xx_dma_tx_status(struct dma_chan *chan,
758 dma_cookie_t cookie, struct dma_tx_state *txstate)
759{
760 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
761 struct s3c24xx_txd *txd;
762 struct s3c24xx_sg *dsg;
763 struct virt_dma_desc *vd;
764 unsigned long flags;
765 enum dma_status ret;
766 size_t bytes = 0;
767
768 spin_lock_irqsave(&s3cchan->vc.lock, flags);
769 ret = dma_cookie_status(chan, cookie, txstate);
770
771 /*
772 * There's no point calculating the residue if there's
773 * no txstate to store the value.
774 */
775 if (ret == DMA_COMPLETE || !txstate) {
776 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
777 return ret;
778 }
779
780 vd = vchan_find_desc(&s3cchan->vc, cookie);
781 if (vd) {
782 /* On the issued list, so hasn't been processed yet */
783 txd = to_s3c24xx_txd(&vd->tx);
784
785 list_for_each_entry(dsg, &txd->dsg_list, node)
786 bytes += dsg->len;
787 } else {
788 /*
789 * Currently running, so sum over the pending sg's and
790 * the currently active one.
791 */
792 txd = s3cchan->at;
793
794 dsg = list_entry(txd->at, struct s3c24xx_sg, node);
795 list_for_each_entry_from(dsg, &txd->dsg_list, node)
796 bytes += dsg->len;
797
798 bytes += s3c24xx_dma_getbytes_chan(s3cchan);
799 }
800 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
801
802 /*
803 * This cookie not complete yet
804 * Get number of bytes left in the active transactions and queue
805 */
806 dma_set_residue(txstate, bytes);
807
808 /* Whether waiting or running, we're in progress */
809 return ret;
810}
811
812/*
813 * Initialize a descriptor to be used by memcpy submit
814 */
815static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy(
816 struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
817 size_t len, unsigned long flags)
818{
819 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
820 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
821 struct s3c24xx_txd *txd;
822 struct s3c24xx_sg *dsg;
823 int src_mod, dest_mod;
824
825 dev_dbg(&s3cdma->pdev->dev, "prepare memcpy of %zu bytes from %s\n",
826 len, s3cchan->name);
827
828 if ((len & S3C24XX_DCON_TC_MASK) != len) {
829 dev_err(&s3cdma->pdev->dev, "memcpy size %zu to large\n", len);
830 return NULL;
831 }
832
833 txd = s3c24xx_dma_get_txd();
834 if (!txd)
835 return NULL;
836
837 dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
838 if (!dsg) {
839 s3c24xx_dma_free_txd(txd);
840 return NULL;
841 }
842 list_add_tail(&dsg->node, &txd->dsg_list);
843
844 dsg->src_addr = src;
845 dsg->dst_addr = dest;
846 dsg->len = len;
847
848 /*
849 * Determine a suitable transfer width.
850 * The DMA controller cannot fetch/store information which is not
851 * naturally aligned on the bus, i.e., a 4 byte fetch must start at
852 * an address divisible by 4 - more generally addr % width must be 0.
853 */
854 src_mod = src % 4;
855 dest_mod = dest % 4;
856 switch (len % 4) {
857 case 0:
858 txd->width = (src_mod == 0 && dest_mod == 0) ? 4 : 1;
859 break;
860 case 2:
861 txd->width = ((src_mod == 2 || src_mod == 0) &&
862 (dest_mod == 2 || dest_mod == 0)) ? 2 : 1;
863 break;
864 default:
865 txd->width = 1;
866 break;
867 }
868
869 txd->disrcc = S3C24XX_DISRCC_LOC_AHB | S3C24XX_DISRCC_INC_INCREMENT;
870 txd->didstc = S3C24XX_DIDSTC_LOC_AHB | S3C24XX_DIDSTC_INC_INCREMENT;
871 txd->dcon |= S3C24XX_DCON_DEMAND | S3C24XX_DCON_SYNC_HCLK |
872 S3C24XX_DCON_SERV_WHOLE;
873
874 return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
875}
876
877static struct dma_async_tx_descriptor *s3c24xx_dma_prep_dma_cyclic(
878 struct dma_chan *chan, dma_addr_t addr, size_t size, size_t period,
879 enum dma_transfer_direction direction, unsigned long flags)
880{
881 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
882 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
883 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
884 struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
885 struct s3c24xx_txd *txd;
886 struct s3c24xx_sg *dsg;
887 unsigned sg_len;
888 dma_addr_t slave_addr;
889 u32 hwcfg = 0;
890 int i;
891
892 dev_dbg(&s3cdma->pdev->dev,
893 "prepare cyclic transaction of %zu bytes with period %zu from %s\n",
894 size, period, s3cchan->name);
895
896 if (!is_slave_direction(direction)) {
897 dev_err(&s3cdma->pdev->dev,
898 "direction %d unsupported\n", direction);
899 return NULL;
900 }
901
902 txd = s3c24xx_dma_get_txd();
903 if (!txd)
904 return NULL;
905
906 txd->cyclic = 1;
907
908 if (cdata->handshake)
909 txd->dcon |= S3C24XX_DCON_HANDSHAKE;
910
911 switch (cdata->bus) {
912 case S3C24XX_DMA_APB:
913 txd->dcon |= S3C24XX_DCON_SYNC_PCLK;
914 hwcfg |= S3C24XX_DISRCC_LOC_APB;
915 break;
916 case S3C24XX_DMA_AHB:
917 txd->dcon |= S3C24XX_DCON_SYNC_HCLK;
918 hwcfg |= S3C24XX_DISRCC_LOC_AHB;
919 break;
920 }
921
922 /*
923 * Always assume our peripheral desintation is a fixed
924 * address in memory.
925 */
926 hwcfg |= S3C24XX_DISRCC_INC_FIXED;
927
928 /*
929 * Individual dma operations are requested by the slave,
930 * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE).
931 */
932 txd->dcon |= S3C24XX_DCON_SERV_SINGLE;
933
934 if (direction == DMA_MEM_TO_DEV) {
935 txd->disrcc = S3C24XX_DISRCC_LOC_AHB |
936 S3C24XX_DISRCC_INC_INCREMENT;
937 txd->didstc = hwcfg;
938 slave_addr = s3cchan->cfg.dst_addr;
939 txd->width = s3cchan->cfg.dst_addr_width;
940 } else {
941 txd->disrcc = hwcfg;
942 txd->didstc = S3C24XX_DIDSTC_LOC_AHB |
943 S3C24XX_DIDSTC_INC_INCREMENT;
944 slave_addr = s3cchan->cfg.src_addr;
945 txd->width = s3cchan->cfg.src_addr_width;
946 }
947
948 sg_len = size / period;
949
950 for (i = 0; i < sg_len; i++) {
951 dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
952 if (!dsg) {
953 s3c24xx_dma_free_txd(txd);
954 return NULL;
955 }
956 list_add_tail(&dsg->node, &txd->dsg_list);
957
958 dsg->len = period;
959 /* Check last period length */
960 if (i == sg_len - 1)
961 dsg->len = size - period * i;
962 if (direction == DMA_MEM_TO_DEV) {
963 dsg->src_addr = addr + period * i;
964 dsg->dst_addr = slave_addr;
965 } else { /* DMA_DEV_TO_MEM */
966 dsg->src_addr = slave_addr;
967 dsg->dst_addr = addr + period * i;
968 }
969 }
970
971 return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
972}
973
974static struct dma_async_tx_descriptor *s3c24xx_dma_prep_slave_sg(
975 struct dma_chan *chan, struct scatterlist *sgl,
976 unsigned int sg_len, enum dma_transfer_direction direction,
977 unsigned long flags, void *context)
978{
979 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
980 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
981 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
982 struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
983 struct s3c24xx_txd *txd;
984 struct s3c24xx_sg *dsg;
985 struct scatterlist *sg;
986 dma_addr_t slave_addr;
987 u32 hwcfg = 0;
988 int tmp;
989
990 dev_dbg(&s3cdma->pdev->dev, "prepare transaction of %d bytes from %s\n",
991 sg_dma_len(sgl), s3cchan->name);
992
993 txd = s3c24xx_dma_get_txd();
994 if (!txd)
995 return NULL;
996
997 if (cdata->handshake)
998 txd->dcon |= S3C24XX_DCON_HANDSHAKE;
999
1000 switch (cdata->bus) {
1001 case S3C24XX_DMA_APB:
1002 txd->dcon |= S3C24XX_DCON_SYNC_PCLK;
1003 hwcfg |= S3C24XX_DISRCC_LOC_APB;
1004 break;
1005 case S3C24XX_DMA_AHB:
1006 txd->dcon |= S3C24XX_DCON_SYNC_HCLK;
1007 hwcfg |= S3C24XX_DISRCC_LOC_AHB;
1008 break;
1009 }
1010
1011 /*
1012 * Always assume our peripheral desintation is a fixed
1013 * address in memory.
1014 */
1015 hwcfg |= S3C24XX_DISRCC_INC_FIXED;
1016
1017 /*
1018 * Individual dma operations are requested by the slave,
1019 * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE).
1020 */
1021 txd->dcon |= S3C24XX_DCON_SERV_SINGLE;
1022
1023 if (direction == DMA_MEM_TO_DEV) {
1024 txd->disrcc = S3C24XX_DISRCC_LOC_AHB |
1025 S3C24XX_DISRCC_INC_INCREMENT;
1026 txd->didstc = hwcfg;
1027 slave_addr = s3cchan->cfg.dst_addr;
1028 txd->width = s3cchan->cfg.dst_addr_width;
1029 } else if (direction == DMA_DEV_TO_MEM) {
1030 txd->disrcc = hwcfg;
1031 txd->didstc = S3C24XX_DIDSTC_LOC_AHB |
1032 S3C24XX_DIDSTC_INC_INCREMENT;
1033 slave_addr = s3cchan->cfg.src_addr;
1034 txd->width = s3cchan->cfg.src_addr_width;
1035 } else {
1036 s3c24xx_dma_free_txd(txd);
1037 dev_err(&s3cdma->pdev->dev,
1038 "direction %d unsupported\n", direction);
1039 return NULL;
1040 }
1041
1042 for_each_sg(sgl, sg, sg_len, tmp) {
1043 dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
1044 if (!dsg) {
1045 s3c24xx_dma_free_txd(txd);
1046 return NULL;
1047 }
1048 list_add_tail(&dsg->node, &txd->dsg_list);
1049
1050 dsg->len = sg_dma_len(sg);
1051 if (direction == DMA_MEM_TO_DEV) {
1052 dsg->src_addr = sg_dma_address(sg);
1053 dsg->dst_addr = slave_addr;
1054 } else { /* DMA_DEV_TO_MEM */
1055 dsg->src_addr = slave_addr;
1056 dsg->dst_addr = sg_dma_address(sg);
1057 }
1058 }
1059
1060 return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
1061}
1062
1063/*
1064 * Slave transactions callback to the slave device to allow
1065 * synchronization of slave DMA signals with the DMAC enable
1066 */
1067static void s3c24xx_dma_issue_pending(struct dma_chan *chan)
1068{
1069 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
1070 unsigned long flags;
1071
1072 spin_lock_irqsave(&s3cchan->vc.lock, flags);
1073 if (vchan_issue_pending(&s3cchan->vc)) {
1074 if (!s3cchan->phy && s3cchan->state != S3C24XX_DMA_CHAN_WAITING)
1075 s3c24xx_dma_phy_alloc_and_start(s3cchan);
1076 }
1077 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
1078}
1079
1080/*
1081 * Bringup and teardown
1082 */
1083
1084/*
1085 * Initialise the DMAC memcpy/slave channels.
1086 * Make a local wrapper to hold required data
1087 */
1088static int s3c24xx_dma_init_virtual_channels(struct s3c24xx_dma_engine *s3cdma,
1089 struct dma_device *dmadev, unsigned int channels, bool slave)
1090{
1091 struct s3c24xx_dma_chan *chan;
1092 int i;
1093
1094 INIT_LIST_HEAD(&dmadev->channels);
1095
1096 /*
1097 * Register as many many memcpy as we have physical channels,
1098 * we won't always be able to use all but the code will have
1099 * to cope with that situation.
1100 */
1101 for (i = 0; i < channels; i++) {
1102 chan = devm_kzalloc(dmadev->dev, sizeof(*chan), GFP_KERNEL);
1103 if (!chan)
1104 return -ENOMEM;
1105
1106 chan->id = i;
1107 chan->host = s3cdma;
1108 chan->state = S3C24XX_DMA_CHAN_IDLE;
1109
1110 if (slave) {
1111 chan->slave = true;
1112 chan->name = kasprintf(GFP_KERNEL, "slave%d", i);
1113 if (!chan->name)
1114 return -ENOMEM;
1115 } else {
1116 chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i);
1117 if (!chan->name)
1118 return -ENOMEM;
1119 }
1120 dev_dbg(dmadev->dev,
1121 "initialize virtual channel \"%s\"\n",
1122 chan->name);
1123
1124 chan->vc.desc_free = s3c24xx_dma_desc_free;
1125 vchan_init(&chan->vc, dmadev);
1126 }
1127 dev_info(dmadev->dev, "initialized %d virtual %s channels\n",
1128 i, slave ? "slave" : "memcpy");
1129 return i;
1130}
1131
1132static void s3c24xx_dma_free_virtual_channels(struct dma_device *dmadev)
1133{
1134 struct s3c24xx_dma_chan *chan = NULL;
1135 struct s3c24xx_dma_chan *next;
1136
1137 list_for_each_entry_safe(chan,
1138 next, &dmadev->channels, vc.chan.device_node) {
1139 list_del(&chan->vc.chan.device_node);
1140 tasklet_kill(&chan->vc.task);
1141 }
1142}
1143
1144/* s3c2410, s3c2440 and s3c2442 have a 0x40 stride without separate clocks */
1145static struct soc_data soc_s3c2410 = {
1146 .stride = 0x40,
1147 .has_reqsel = false,
1148 .has_clocks = false,
1149};
1150
1151/* s3c2412 and s3c2413 have a 0x40 stride and dmareqsel mechanism */
1152static struct soc_data soc_s3c2412 = {
1153 .stride = 0x40,
1154 .has_reqsel = true,
1155 .has_clocks = true,
1156};
1157
1158/* s3c2443 and following have a 0x100 stride and dmareqsel mechanism */
1159static struct soc_data soc_s3c2443 = {
1160 .stride = 0x100,
1161 .has_reqsel = true,
1162 .has_clocks = true,
1163};
1164
1165static const struct platform_device_id s3c24xx_dma_driver_ids[] = {
1166 {
1167 .name = "s3c2410-dma",
1168 .driver_data = (kernel_ulong_t)&soc_s3c2410,
1169 }, {
1170 .name = "s3c2412-dma",
1171 .driver_data = (kernel_ulong_t)&soc_s3c2412,
1172 }, {
1173 .name = "s3c2443-dma",
1174 .driver_data = (kernel_ulong_t)&soc_s3c2443,
1175 },
1176 { },
1177};
1178
1179static struct soc_data *s3c24xx_dma_get_soc_data(struct platform_device *pdev)
1180{
1181 return (struct soc_data *)
1182 platform_get_device_id(pdev)->driver_data;
1183}
1184
1185static int s3c24xx_dma_probe(struct platform_device *pdev)
1186{
1187 const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev);
1188 struct s3c24xx_dma_engine *s3cdma;
1189 struct soc_data *sdata;
1190 struct resource *res;
1191 int ret;
1192 int i;
1193
1194 if (!pdata) {
1195 dev_err(&pdev->dev, "platform data missing\n");
1196 return -ENODEV;
1197 }
1198
1199 /* Basic sanity check */
1200 if (pdata->num_phy_channels > MAX_DMA_CHANNELS) {
1201 dev_err(&pdev->dev, "too many dma channels %d, max %d\n",
1202 pdata->num_phy_channels, MAX_DMA_CHANNELS);
1203 return -EINVAL;
1204 }
1205
1206 sdata = s3c24xx_dma_get_soc_data(pdev);
1207 if (!sdata)
1208 return -EINVAL;
1209
1210 s3cdma = devm_kzalloc(&pdev->dev, sizeof(*s3cdma), GFP_KERNEL);
1211 if (!s3cdma)
1212 return -ENOMEM;
1213
1214 s3cdma->pdev = pdev;
1215 s3cdma->pdata = pdata;
1216 s3cdma->sdata = sdata;
1217
1218 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1219 s3cdma->base = devm_ioremap_resource(&pdev->dev, res);
1220 if (IS_ERR(s3cdma->base))
1221 return PTR_ERR(s3cdma->base);
1222
1223 s3cdma->phy_chans = devm_kcalloc(&pdev->dev,
1224 pdata->num_phy_channels,
1225 sizeof(struct s3c24xx_dma_phy),
1226 GFP_KERNEL);
1227 if (!s3cdma->phy_chans)
1228 return -ENOMEM;
1229
1230 /* acquire irqs and clocks for all physical channels */
1231 for (i = 0; i < pdata->num_phy_channels; i++) {
1232 struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
1233 char clk_name[6];
1234
1235 phy->id = i;
1236 phy->base = s3cdma->base + (i * sdata->stride);
1237 phy->host = s3cdma;
1238
1239 phy->irq = platform_get_irq(pdev, i);
1240 if (phy->irq < 0)
1241 continue;
1242
1243 ret = devm_request_irq(&pdev->dev, phy->irq, s3c24xx_dma_irq,
1244 0, pdev->name, phy);
1245 if (ret) {
1246 dev_err(&pdev->dev, "Unable to request irq for channel %d, error %d\n",
1247 i, ret);
1248 continue;
1249 }
1250
1251 if (sdata->has_clocks) {
1252 sprintf(clk_name, "dma.%d", i);
1253 phy->clk = devm_clk_get(&pdev->dev, clk_name);
1254 if (IS_ERR(phy->clk) && sdata->has_clocks) {
1255 dev_err(&pdev->dev, "unable to acquire clock for channel %d, error %lu\n",
1256 i, PTR_ERR(phy->clk));
1257 continue;
1258 }
1259
1260 ret = clk_prepare(phy->clk);
1261 if (ret) {
1262 dev_err(&pdev->dev, "clock for phy %d failed, error %d\n",
1263 i, ret);
1264 continue;
1265 }
1266 }
1267
1268 spin_lock_init(&phy->lock);
1269 phy->valid = true;
1270
1271 dev_dbg(&pdev->dev, "physical channel %d is %s\n",
1272 i, s3c24xx_dma_phy_busy(phy) ? "BUSY" : "FREE");
1273 }
1274
1275 /* Initialize memcpy engine */
1276 dma_cap_set(DMA_MEMCPY, s3cdma->memcpy.cap_mask);
1277 dma_cap_set(DMA_PRIVATE, s3cdma->memcpy.cap_mask);
1278 s3cdma->memcpy.dev = &pdev->dev;
1279 s3cdma->memcpy.device_free_chan_resources =
1280 s3c24xx_dma_free_chan_resources;
1281 s3cdma->memcpy.device_prep_dma_memcpy = s3c24xx_dma_prep_memcpy;
1282 s3cdma->memcpy.device_tx_status = s3c24xx_dma_tx_status;
1283 s3cdma->memcpy.device_issue_pending = s3c24xx_dma_issue_pending;
1284 s3cdma->memcpy.device_config = s3c24xx_dma_set_runtime_config;
1285 s3cdma->memcpy.device_terminate_all = s3c24xx_dma_terminate_all;
1286 s3cdma->memcpy.device_synchronize = s3c24xx_dma_synchronize;
1287
1288 /* Initialize slave engine for SoC internal dedicated peripherals */
1289 dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask);
1290 dma_cap_set(DMA_CYCLIC, s3cdma->slave.cap_mask);
1291 dma_cap_set(DMA_PRIVATE, s3cdma->slave.cap_mask);
1292 s3cdma->slave.dev = &pdev->dev;
1293 s3cdma->slave.device_free_chan_resources =
1294 s3c24xx_dma_free_chan_resources;
1295 s3cdma->slave.device_tx_status = s3c24xx_dma_tx_status;
1296 s3cdma->slave.device_issue_pending = s3c24xx_dma_issue_pending;
1297 s3cdma->slave.device_prep_slave_sg = s3c24xx_dma_prep_slave_sg;
1298 s3cdma->slave.device_prep_dma_cyclic = s3c24xx_dma_prep_dma_cyclic;
1299 s3cdma->slave.device_config = s3c24xx_dma_set_runtime_config;
1300 s3cdma->slave.device_terminate_all = s3c24xx_dma_terminate_all;
1301 s3cdma->slave.device_synchronize = s3c24xx_dma_synchronize;
1302 s3cdma->slave.filter.map = pdata->slave_map;
1303 s3cdma->slave.filter.mapcnt = pdata->slavecnt;
1304 s3cdma->slave.filter.fn = s3c24xx_dma_filter;
1305
1306 /* Register as many memcpy channels as there are physical channels */
1307 ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->memcpy,
1308 pdata->num_phy_channels, false);
1309 if (ret <= 0) {
1310 dev_warn(&pdev->dev,
1311 "%s failed to enumerate memcpy channels - %d\n",
1312 __func__, ret);
1313 goto err_memcpy;
1314 }
1315
1316 /* Register slave channels */
1317 ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->slave,
1318 pdata->num_channels, true);
1319 if (ret <= 0) {
1320 dev_warn(&pdev->dev,
1321 "%s failed to enumerate slave channels - %d\n",
1322 __func__, ret);
1323 goto err_slave;
1324 }
1325
1326 ret = dma_async_device_register(&s3cdma->memcpy);
1327 if (ret) {
1328 dev_warn(&pdev->dev,
1329 "%s failed to register memcpy as an async device - %d\n",
1330 __func__, ret);
1331 goto err_memcpy_reg;
1332 }
1333
1334 ret = dma_async_device_register(&s3cdma->slave);
1335 if (ret) {
1336 dev_warn(&pdev->dev,
1337 "%s failed to register slave as an async device - %d\n",
1338 __func__, ret);
1339 goto err_slave_reg;
1340 }
1341
1342 platform_set_drvdata(pdev, s3cdma);
1343 dev_info(&pdev->dev, "Loaded dma driver with %d physical channels\n",
1344 pdata->num_phy_channels);
1345
1346 return 0;
1347
1348err_slave_reg:
1349 dma_async_device_unregister(&s3cdma->memcpy);
1350err_memcpy_reg:
1351 s3c24xx_dma_free_virtual_channels(&s3cdma->slave);
1352err_slave:
1353 s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy);
1354err_memcpy:
1355 if (sdata->has_clocks)
1356 for (i = 0; i < pdata->num_phy_channels; i++) {
1357 struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
1358 if (phy->valid)
1359 clk_unprepare(phy->clk);
1360 }
1361
1362 return ret;
1363}
1364
1365static void s3c24xx_dma_free_irq(struct platform_device *pdev,
1366 struct s3c24xx_dma_engine *s3cdma)
1367{
1368 int i;
1369
1370 for (i = 0; i < s3cdma->pdata->num_phy_channels; i++) {
1371 struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
1372
1373 devm_free_irq(&pdev->dev, phy->irq, phy);
1374 }
1375}
1376
1377static int s3c24xx_dma_remove(struct platform_device *pdev)
1378{
1379 const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev);
1380 struct s3c24xx_dma_engine *s3cdma = platform_get_drvdata(pdev);
1381 struct soc_data *sdata = s3c24xx_dma_get_soc_data(pdev);
1382 int i;
1383
1384 dma_async_device_unregister(&s3cdma->slave);
1385 dma_async_device_unregister(&s3cdma->memcpy);
1386
1387 s3c24xx_dma_free_irq(pdev, s3cdma);
1388
1389 s3c24xx_dma_free_virtual_channels(&s3cdma->slave);
1390 s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy);
1391
1392 if (sdata->has_clocks)
1393 for (i = 0; i < pdata->num_phy_channels; i++) {
1394 struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
1395 if (phy->valid)
1396 clk_unprepare(phy->clk);
1397 }
1398
1399 return 0;
1400}
1401
1402static struct platform_driver s3c24xx_dma_driver = {
1403 .driver = {
1404 .name = "s3c24xx-dma",
1405 },
1406 .id_table = s3c24xx_dma_driver_ids,
1407 .probe = s3c24xx_dma_probe,
1408 .remove = s3c24xx_dma_remove,
1409};
1410
1411module_platform_driver(s3c24xx_dma_driver);
1412
1413bool s3c24xx_dma_filter(struct dma_chan *chan, void *param)
1414{
1415 struct s3c24xx_dma_chan *s3cchan;
1416
1417 if (chan->device->dev->driver != &s3c24xx_dma_driver.driver)
1418 return false;
1419
1420 s3cchan = to_s3c24xx_dma_chan(chan);
1421
1422 return s3cchan->id == (uintptr_t)param;
1423}
1424EXPORT_SYMBOL(s3c24xx_dma_filter);
1425
1426MODULE_DESCRIPTION("S3C24XX DMA Driver");
1427MODULE_AUTHOR("Heiko Stuebner");
1428MODULE_LICENSE("GPL v2");
1/*
2 * S3C24XX DMA handling
3 *
4 * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>
5 *
6 * based on amba-pl08x.c
7 *
8 * Copyright (c) 2006 ARM Ltd.
9 * Copyright (c) 2010 ST-Ericsson SA
10 *
11 * Author: Peter Pearse <peter.pearse@arm.com>
12 * Author: Linus Walleij <linus.walleij@stericsson.com>
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the Free
16 * Software Foundation; either version 2 of the License, or (at your option)
17 * any later version.
18 *
19 * The DMA controllers in S3C24XX SoCs have a varying number of DMA signals
20 * that can be routed to any of the 4 to 8 hardware-channels.
21 *
22 * Therefore on these DMA controllers the number of channels
23 * and the number of incoming DMA signals are two totally different things.
24 * It is usually not possible to theoretically handle all physical signals,
25 * so a multiplexing scheme with possible denial of use is necessary.
26 *
27 * Open items:
28 * - bursts
29 */
30
31#include <linux/platform_device.h>
32#include <linux/types.h>
33#include <linux/dmaengine.h>
34#include <linux/dma-mapping.h>
35#include <linux/interrupt.h>
36#include <linux/clk.h>
37#include <linux/module.h>
38#include <linux/slab.h>
39#include <linux/platform_data/dma-s3c24xx.h>
40
41#include "dmaengine.h"
42#include "virt-dma.h"
43
44#define MAX_DMA_CHANNELS 8
45
46#define S3C24XX_DISRC 0x00
47#define S3C24XX_DISRCC 0x04
48#define S3C24XX_DISRCC_INC_INCREMENT 0
49#define S3C24XX_DISRCC_INC_FIXED BIT(0)
50#define S3C24XX_DISRCC_LOC_AHB 0
51#define S3C24XX_DISRCC_LOC_APB BIT(1)
52
53#define S3C24XX_DIDST 0x08
54#define S3C24XX_DIDSTC 0x0c
55#define S3C24XX_DIDSTC_INC_INCREMENT 0
56#define S3C24XX_DIDSTC_INC_FIXED BIT(0)
57#define S3C24XX_DIDSTC_LOC_AHB 0
58#define S3C24XX_DIDSTC_LOC_APB BIT(1)
59#define S3C24XX_DIDSTC_INT_TC0 0
60#define S3C24XX_DIDSTC_INT_RELOAD BIT(2)
61
62#define S3C24XX_DCON 0x10
63
64#define S3C24XX_DCON_TC_MASK 0xfffff
65#define S3C24XX_DCON_DSZ_BYTE (0 << 20)
66#define S3C24XX_DCON_DSZ_HALFWORD (1 << 20)
67#define S3C24XX_DCON_DSZ_WORD (2 << 20)
68#define S3C24XX_DCON_DSZ_MASK (3 << 20)
69#define S3C24XX_DCON_DSZ_SHIFT 20
70#define S3C24XX_DCON_AUTORELOAD 0
71#define S3C24XX_DCON_NORELOAD BIT(22)
72#define S3C24XX_DCON_HWTRIG BIT(23)
73#define S3C24XX_DCON_HWSRC_SHIFT 24
74#define S3C24XX_DCON_SERV_SINGLE 0
75#define S3C24XX_DCON_SERV_WHOLE BIT(27)
76#define S3C24XX_DCON_TSZ_UNIT 0
77#define S3C24XX_DCON_TSZ_BURST4 BIT(28)
78#define S3C24XX_DCON_INT BIT(29)
79#define S3C24XX_DCON_SYNC_PCLK 0
80#define S3C24XX_DCON_SYNC_HCLK BIT(30)
81#define S3C24XX_DCON_DEMAND 0
82#define S3C24XX_DCON_HANDSHAKE BIT(31)
83
84#define S3C24XX_DSTAT 0x14
85#define S3C24XX_DSTAT_STAT_BUSY BIT(20)
86#define S3C24XX_DSTAT_CURRTC_MASK 0xfffff
87
88#define S3C24XX_DMASKTRIG 0x20
89#define S3C24XX_DMASKTRIG_SWTRIG BIT(0)
90#define S3C24XX_DMASKTRIG_ON BIT(1)
91#define S3C24XX_DMASKTRIG_STOP BIT(2)
92
93#define S3C24XX_DMAREQSEL 0x24
94#define S3C24XX_DMAREQSEL_HW BIT(0)
95
96/*
97 * S3C2410, S3C2440 and S3C2442 SoCs cannot select any physical channel
98 * for a DMA source. Instead only specific channels are valid.
99 * All of these SoCs have 4 physical channels and the number of request
100 * source bits is 3. Additionally we also need 1 bit to mark the channel
101 * as valid.
102 * Therefore we separate the chansel element of the channel data into 4
103 * parts of 4 bits each, to hold the information if the channel is valid
104 * and the hw request source to use.
105 *
106 * Example:
107 * SDI is valid on channels 0, 2 and 3 - with varying hw request sources.
108 * For it the chansel field would look like
109 *
110 * ((BIT(3) | 1) << 3 * 4) | // channel 3, with request source 1
111 * ((BIT(3) | 2) << 2 * 4) | // channel 2, with request source 2
112 * ((BIT(3) | 2) << 0 * 4) // channel 0, with request source 2
113 */
114#define S3C24XX_CHANSEL_WIDTH 4
115#define S3C24XX_CHANSEL_VALID BIT(3)
116#define S3C24XX_CHANSEL_REQ_MASK 7
117
118/*
119 * struct soc_data - vendor-specific config parameters for individual SoCs
120 * @stride: spacing between the registers of each channel
121 * @has_reqsel: does the controller use the newer requestselection mechanism
122 * @has_clocks: are controllable dma-clocks present
123 */
124struct soc_data {
125 int stride;
126 bool has_reqsel;
127 bool has_clocks;
128};
129
130/*
131 * enum s3c24xx_dma_chan_state - holds the virtual channel states
132 * @S3C24XX_DMA_CHAN_IDLE: the channel is idle
133 * @S3C24XX_DMA_CHAN_RUNNING: the channel has allocated a physical transport
134 * channel and is running a transfer on it
135 * @S3C24XX_DMA_CHAN_WAITING: the channel is waiting for a physical transport
136 * channel to become available (only pertains to memcpy channels)
137 */
138enum s3c24xx_dma_chan_state {
139 S3C24XX_DMA_CHAN_IDLE,
140 S3C24XX_DMA_CHAN_RUNNING,
141 S3C24XX_DMA_CHAN_WAITING,
142};
143
144/*
145 * struct s3c24xx_sg - structure containing data per sg
146 * @src_addr: src address of sg
147 * @dst_addr: dst address of sg
148 * @len: transfer len in bytes
149 * @node: node for txd's dsg_list
150 */
151struct s3c24xx_sg {
152 dma_addr_t src_addr;
153 dma_addr_t dst_addr;
154 size_t len;
155 struct list_head node;
156};
157
158/*
159 * struct s3c24xx_txd - wrapper for struct dma_async_tx_descriptor
160 * @vd: virtual DMA descriptor
161 * @dsg_list: list of children sg's
162 * @at: sg currently being transfered
163 * @width: transfer width
164 * @disrcc: value for source control register
165 * @didstc: value for destination control register
166 * @dcon: base value for dcon register
167 * @cyclic: indicate cyclic transfer
168 */
169struct s3c24xx_txd {
170 struct virt_dma_desc vd;
171 struct list_head dsg_list;
172 struct list_head *at;
173 u8 width;
174 u32 disrcc;
175 u32 didstc;
176 u32 dcon;
177 bool cyclic;
178};
179
180struct s3c24xx_dma_chan;
181
182/*
183 * struct s3c24xx_dma_phy - holder for the physical channels
184 * @id: physical index to this channel
185 * @valid: does the channel have all required elements
186 * @base: virtual memory base (remapped) for the this channel
187 * @irq: interrupt for this channel
188 * @clk: clock for this channel
189 * @lock: a lock to use when altering an instance of this struct
190 * @serving: virtual channel currently being served by this physicalchannel
191 * @host: a pointer to the host (internal use)
192 */
193struct s3c24xx_dma_phy {
194 unsigned int id;
195 bool valid;
196 void __iomem *base;
197 int irq;
198 struct clk *clk;
199 spinlock_t lock;
200 struct s3c24xx_dma_chan *serving;
201 struct s3c24xx_dma_engine *host;
202};
203
204/*
205 * struct s3c24xx_dma_chan - this structure wraps a DMA ENGINE channel
206 * @id: the id of the channel
207 * @name: name of the channel
208 * @vc: wrappped virtual channel
209 * @phy: the physical channel utilized by this channel, if there is one
210 * @runtime_addr: address for RX/TX according to the runtime config
211 * @at: active transaction on this channel
212 * @lock: a lock for this channel data
213 * @host: a pointer to the host (internal use)
214 * @state: whether the channel is idle, running etc
215 * @slave: whether this channel is a device (slave) or for memcpy
216 */
217struct s3c24xx_dma_chan {
218 int id;
219 const char *name;
220 struct virt_dma_chan vc;
221 struct s3c24xx_dma_phy *phy;
222 struct dma_slave_config cfg;
223 struct s3c24xx_txd *at;
224 struct s3c24xx_dma_engine *host;
225 enum s3c24xx_dma_chan_state state;
226 bool slave;
227};
228
229/*
230 * struct s3c24xx_dma_engine - the local state holder for the S3C24XX
231 * @pdev: the corresponding platform device
232 * @pdata: platform data passed in from the platform/machine
233 * @base: virtual memory base (remapped)
234 * @slave: slave engine for this instance
235 * @memcpy: memcpy engine for this instance
236 * @phy_chans: array of data for the physical channels
237 */
238struct s3c24xx_dma_engine {
239 struct platform_device *pdev;
240 const struct s3c24xx_dma_platdata *pdata;
241 struct soc_data *sdata;
242 void __iomem *base;
243 struct dma_device slave;
244 struct dma_device memcpy;
245 struct s3c24xx_dma_phy *phy_chans;
246};
247
248/*
249 * Physical channel handling
250 */
251
252/*
253 * Check whether a certain channel is busy or not.
254 */
255static int s3c24xx_dma_phy_busy(struct s3c24xx_dma_phy *phy)
256{
257 unsigned int val = readl(phy->base + S3C24XX_DSTAT);
258 return val & S3C24XX_DSTAT_STAT_BUSY;
259}
260
261static bool s3c24xx_dma_phy_valid(struct s3c24xx_dma_chan *s3cchan,
262 struct s3c24xx_dma_phy *phy)
263{
264 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
265 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
266 struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
267 int phyvalid;
268
269 /* every phy is valid for memcopy channels */
270 if (!s3cchan->slave)
271 return true;
272
273 /* On newer variants all phys can be used for all virtual channels */
274 if (s3cdma->sdata->has_reqsel)
275 return true;
276
277 phyvalid = (cdata->chansel >> (phy->id * S3C24XX_CHANSEL_WIDTH));
278 return (phyvalid & S3C24XX_CHANSEL_VALID) ? true : false;
279}
280
281/*
282 * Allocate a physical channel for a virtual channel
283 *
284 * Try to locate a physical channel to be used for this transfer. If all
285 * are taken return NULL and the requester will have to cope by using
286 * some fallback PIO mode or retrying later.
287 */
288static
289struct s3c24xx_dma_phy *s3c24xx_dma_get_phy(struct s3c24xx_dma_chan *s3cchan)
290{
291 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
292 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
293 struct s3c24xx_dma_channel *cdata;
294 struct s3c24xx_dma_phy *phy = NULL;
295 unsigned long flags;
296 int i;
297 int ret;
298
299 if (s3cchan->slave)
300 cdata = &pdata->channels[s3cchan->id];
301
302 for (i = 0; i < s3cdma->pdata->num_phy_channels; i++) {
303 phy = &s3cdma->phy_chans[i];
304
305 if (!phy->valid)
306 continue;
307
308 if (!s3c24xx_dma_phy_valid(s3cchan, phy))
309 continue;
310
311 spin_lock_irqsave(&phy->lock, flags);
312
313 if (!phy->serving) {
314 phy->serving = s3cchan;
315 spin_unlock_irqrestore(&phy->lock, flags);
316 break;
317 }
318
319 spin_unlock_irqrestore(&phy->lock, flags);
320 }
321
322 /* No physical channel available, cope with it */
323 if (i == s3cdma->pdata->num_phy_channels) {
324 dev_warn(&s3cdma->pdev->dev, "no phy channel available\n");
325 return NULL;
326 }
327
328 /* start the phy clock */
329 if (s3cdma->sdata->has_clocks) {
330 ret = clk_enable(phy->clk);
331 if (ret) {
332 dev_err(&s3cdma->pdev->dev, "could not enable clock for channel %d, err %d\n",
333 phy->id, ret);
334 phy->serving = NULL;
335 return NULL;
336 }
337 }
338
339 return phy;
340}
341
342/*
343 * Mark the physical channel as free.
344 *
345 * This drops the link between the physical and virtual channel.
346 */
347static inline void s3c24xx_dma_put_phy(struct s3c24xx_dma_phy *phy)
348{
349 struct s3c24xx_dma_engine *s3cdma = phy->host;
350
351 if (s3cdma->sdata->has_clocks)
352 clk_disable(phy->clk);
353
354 phy->serving = NULL;
355}
356
357/*
358 * Stops the channel by writing the stop bit.
359 * This should not be used for an on-going transfer, but as a method of
360 * shutting down a channel (eg, when it's no longer used) or terminating a
361 * transfer.
362 */
363static void s3c24xx_dma_terminate_phy(struct s3c24xx_dma_phy *phy)
364{
365 writel(S3C24XX_DMASKTRIG_STOP, phy->base + S3C24XX_DMASKTRIG);
366}
367
368/*
369 * Virtual channel handling
370 */
371
372static inline
373struct s3c24xx_dma_chan *to_s3c24xx_dma_chan(struct dma_chan *chan)
374{
375 return container_of(chan, struct s3c24xx_dma_chan, vc.chan);
376}
377
378static u32 s3c24xx_dma_getbytes_chan(struct s3c24xx_dma_chan *s3cchan)
379{
380 struct s3c24xx_dma_phy *phy = s3cchan->phy;
381 struct s3c24xx_txd *txd = s3cchan->at;
382 u32 tc = readl(phy->base + S3C24XX_DSTAT) & S3C24XX_DSTAT_CURRTC_MASK;
383
384 return tc * txd->width;
385}
386
387static int s3c24xx_dma_set_runtime_config(struct dma_chan *chan,
388 struct dma_slave_config *config)
389{
390 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
391 unsigned long flags;
392 int ret = 0;
393
394 /* Reject definitely invalid configurations */
395 if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
396 config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
397 return -EINVAL;
398
399 spin_lock_irqsave(&s3cchan->vc.lock, flags);
400
401 if (!s3cchan->slave) {
402 ret = -EINVAL;
403 goto out;
404 }
405
406 s3cchan->cfg = *config;
407
408out:
409 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
410 return ret;
411}
412
413/*
414 * Transfer handling
415 */
416
417static inline
418struct s3c24xx_txd *to_s3c24xx_txd(struct dma_async_tx_descriptor *tx)
419{
420 return container_of(tx, struct s3c24xx_txd, vd.tx);
421}
422
423static struct s3c24xx_txd *s3c24xx_dma_get_txd(void)
424{
425 struct s3c24xx_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
426
427 if (txd) {
428 INIT_LIST_HEAD(&txd->dsg_list);
429 txd->dcon = S3C24XX_DCON_INT | S3C24XX_DCON_NORELOAD;
430 }
431
432 return txd;
433}
434
435static void s3c24xx_dma_free_txd(struct s3c24xx_txd *txd)
436{
437 struct s3c24xx_sg *dsg, *_dsg;
438
439 list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {
440 list_del(&dsg->node);
441 kfree(dsg);
442 }
443
444 kfree(txd);
445}
446
447static void s3c24xx_dma_start_next_sg(struct s3c24xx_dma_chan *s3cchan,
448 struct s3c24xx_txd *txd)
449{
450 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
451 struct s3c24xx_dma_phy *phy = s3cchan->phy;
452 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
453 struct s3c24xx_sg *dsg = list_entry(txd->at, struct s3c24xx_sg, node);
454 u32 dcon = txd->dcon;
455 u32 val;
456
457 /* transfer-size and -count from len and width */
458 switch (txd->width) {
459 case 1:
460 dcon |= S3C24XX_DCON_DSZ_BYTE | dsg->len;
461 break;
462 case 2:
463 dcon |= S3C24XX_DCON_DSZ_HALFWORD | (dsg->len / 2);
464 break;
465 case 4:
466 dcon |= S3C24XX_DCON_DSZ_WORD | (dsg->len / 4);
467 break;
468 }
469
470 if (s3cchan->slave) {
471 struct s3c24xx_dma_channel *cdata =
472 &pdata->channels[s3cchan->id];
473
474 if (s3cdma->sdata->has_reqsel) {
475 writel_relaxed((cdata->chansel << 1) |
476 S3C24XX_DMAREQSEL_HW,
477 phy->base + S3C24XX_DMAREQSEL);
478 } else {
479 int csel = cdata->chansel >> (phy->id *
480 S3C24XX_CHANSEL_WIDTH);
481
482 csel &= S3C24XX_CHANSEL_REQ_MASK;
483 dcon |= csel << S3C24XX_DCON_HWSRC_SHIFT;
484 dcon |= S3C24XX_DCON_HWTRIG;
485 }
486 } else {
487 if (s3cdma->sdata->has_reqsel)
488 writel_relaxed(0, phy->base + S3C24XX_DMAREQSEL);
489 }
490
491 writel_relaxed(dsg->src_addr, phy->base + S3C24XX_DISRC);
492 writel_relaxed(txd->disrcc, phy->base + S3C24XX_DISRCC);
493 writel_relaxed(dsg->dst_addr, phy->base + S3C24XX_DIDST);
494 writel_relaxed(txd->didstc, phy->base + S3C24XX_DIDSTC);
495 writel_relaxed(dcon, phy->base + S3C24XX_DCON);
496
497 val = readl_relaxed(phy->base + S3C24XX_DMASKTRIG);
498 val &= ~S3C24XX_DMASKTRIG_STOP;
499 val |= S3C24XX_DMASKTRIG_ON;
500
501 /* trigger the dma operation for memcpy transfers */
502 if (!s3cchan->slave)
503 val |= S3C24XX_DMASKTRIG_SWTRIG;
504
505 writel(val, phy->base + S3C24XX_DMASKTRIG);
506}
507
508/*
509 * Set the initial DMA register values and start first sg.
510 */
511static void s3c24xx_dma_start_next_txd(struct s3c24xx_dma_chan *s3cchan)
512{
513 struct s3c24xx_dma_phy *phy = s3cchan->phy;
514 struct virt_dma_desc *vd = vchan_next_desc(&s3cchan->vc);
515 struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx);
516
517 list_del(&txd->vd.node);
518
519 s3cchan->at = txd;
520
521 /* Wait for channel inactive */
522 while (s3c24xx_dma_phy_busy(phy))
523 cpu_relax();
524
525 /* point to the first element of the sg list */
526 txd->at = txd->dsg_list.next;
527 s3c24xx_dma_start_next_sg(s3cchan, txd);
528}
529
530static void s3c24xx_dma_free_txd_list(struct s3c24xx_dma_engine *s3cdma,
531 struct s3c24xx_dma_chan *s3cchan)
532{
533 LIST_HEAD(head);
534
535 vchan_get_all_descriptors(&s3cchan->vc, &head);
536 vchan_dma_desc_free_list(&s3cchan->vc, &head);
537}
538
539/*
540 * Try to allocate a physical channel. When successful, assign it to
541 * this virtual channel, and initiate the next descriptor. The
542 * virtual channel lock must be held at this point.
543 */
544static void s3c24xx_dma_phy_alloc_and_start(struct s3c24xx_dma_chan *s3cchan)
545{
546 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
547 struct s3c24xx_dma_phy *phy;
548
549 phy = s3c24xx_dma_get_phy(s3cchan);
550 if (!phy) {
551 dev_dbg(&s3cdma->pdev->dev, "no physical channel available for xfer on %s\n",
552 s3cchan->name);
553 s3cchan->state = S3C24XX_DMA_CHAN_WAITING;
554 return;
555 }
556
557 dev_dbg(&s3cdma->pdev->dev, "allocated physical channel %d for xfer on %s\n",
558 phy->id, s3cchan->name);
559
560 s3cchan->phy = phy;
561 s3cchan->state = S3C24XX_DMA_CHAN_RUNNING;
562
563 s3c24xx_dma_start_next_txd(s3cchan);
564}
565
566static void s3c24xx_dma_phy_reassign_start(struct s3c24xx_dma_phy *phy,
567 struct s3c24xx_dma_chan *s3cchan)
568{
569 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
570
571 dev_dbg(&s3cdma->pdev->dev, "reassigned physical channel %d for xfer on %s\n",
572 phy->id, s3cchan->name);
573
574 /*
575 * We do this without taking the lock; we're really only concerned
576 * about whether this pointer is NULL or not, and we're guaranteed
577 * that this will only be called when it _already_ is non-NULL.
578 */
579 phy->serving = s3cchan;
580 s3cchan->phy = phy;
581 s3cchan->state = S3C24XX_DMA_CHAN_RUNNING;
582 s3c24xx_dma_start_next_txd(s3cchan);
583}
584
585/*
586 * Free a physical DMA channel, potentially reallocating it to another
587 * virtual channel if we have any pending.
588 */
589static void s3c24xx_dma_phy_free(struct s3c24xx_dma_chan *s3cchan)
590{
591 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
592 struct s3c24xx_dma_chan *p, *next;
593
594retry:
595 next = NULL;
596
597 /* Find a waiting virtual channel for the next transfer. */
598 list_for_each_entry(p, &s3cdma->memcpy.channels, vc.chan.device_node)
599 if (p->state == S3C24XX_DMA_CHAN_WAITING) {
600 next = p;
601 break;
602 }
603
604 if (!next) {
605 list_for_each_entry(p, &s3cdma->slave.channels,
606 vc.chan.device_node)
607 if (p->state == S3C24XX_DMA_CHAN_WAITING &&
608 s3c24xx_dma_phy_valid(p, s3cchan->phy)) {
609 next = p;
610 break;
611 }
612 }
613
614 /* Ensure that the physical channel is stopped */
615 s3c24xx_dma_terminate_phy(s3cchan->phy);
616
617 if (next) {
618 bool success;
619
620 /*
621 * Eww. We know this isn't going to deadlock
622 * but lockdep probably doesn't.
623 */
624 spin_lock(&next->vc.lock);
625 /* Re-check the state now that we have the lock */
626 success = next->state == S3C24XX_DMA_CHAN_WAITING;
627 if (success)
628 s3c24xx_dma_phy_reassign_start(s3cchan->phy, next);
629 spin_unlock(&next->vc.lock);
630
631 /* If the state changed, try to find another channel */
632 if (!success)
633 goto retry;
634 } else {
635 /* No more jobs, so free up the physical channel */
636 s3c24xx_dma_put_phy(s3cchan->phy);
637 }
638
639 s3cchan->phy = NULL;
640 s3cchan->state = S3C24XX_DMA_CHAN_IDLE;
641}
642
643static void s3c24xx_dma_desc_free(struct virt_dma_desc *vd)
644{
645 struct s3c24xx_txd *txd = to_s3c24xx_txd(&vd->tx);
646 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(vd->tx.chan);
647
648 if (!s3cchan->slave)
649 dma_descriptor_unmap(&vd->tx);
650
651 s3c24xx_dma_free_txd(txd);
652}
653
654static irqreturn_t s3c24xx_dma_irq(int irq, void *data)
655{
656 struct s3c24xx_dma_phy *phy = data;
657 struct s3c24xx_dma_chan *s3cchan = phy->serving;
658 struct s3c24xx_txd *txd;
659
660 dev_dbg(&phy->host->pdev->dev, "interrupt on channel %d\n", phy->id);
661
662 /*
663 * Interrupts happen to notify the completion of a transfer and the
664 * channel should have moved into its stop state already on its own.
665 * Therefore interrupts on channels not bound to a virtual channel
666 * should never happen. Nevertheless send a terminate command to the
667 * channel if the unlikely case happens.
668 */
669 if (unlikely(!s3cchan)) {
670 dev_err(&phy->host->pdev->dev, "interrupt on unused channel %d\n",
671 phy->id);
672
673 s3c24xx_dma_terminate_phy(phy);
674
675 return IRQ_HANDLED;
676 }
677
678 spin_lock(&s3cchan->vc.lock);
679 txd = s3cchan->at;
680 if (txd) {
681 /* when more sg's are in this txd, start the next one */
682 if (!list_is_last(txd->at, &txd->dsg_list)) {
683 txd->at = txd->at->next;
684 if (txd->cyclic)
685 vchan_cyclic_callback(&txd->vd);
686 s3c24xx_dma_start_next_sg(s3cchan, txd);
687 } else if (!txd->cyclic) {
688 s3cchan->at = NULL;
689 vchan_cookie_complete(&txd->vd);
690
691 /*
692 * And start the next descriptor (if any),
693 * otherwise free this channel.
694 */
695 if (vchan_next_desc(&s3cchan->vc))
696 s3c24xx_dma_start_next_txd(s3cchan);
697 else
698 s3c24xx_dma_phy_free(s3cchan);
699 } else {
700 vchan_cyclic_callback(&txd->vd);
701
702 /* Cyclic: reset at beginning */
703 txd->at = txd->dsg_list.next;
704 s3c24xx_dma_start_next_sg(s3cchan, txd);
705 }
706 }
707 spin_unlock(&s3cchan->vc.lock);
708
709 return IRQ_HANDLED;
710}
711
712/*
713 * The DMA ENGINE API
714 */
715
716static int s3c24xx_dma_terminate_all(struct dma_chan *chan)
717{
718 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
719 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
720 unsigned long flags;
721 int ret = 0;
722
723 spin_lock_irqsave(&s3cchan->vc.lock, flags);
724
725 if (!s3cchan->phy && !s3cchan->at) {
726 dev_err(&s3cdma->pdev->dev, "trying to terminate already stopped channel %d\n",
727 s3cchan->id);
728 ret = -EINVAL;
729 goto unlock;
730 }
731
732 s3cchan->state = S3C24XX_DMA_CHAN_IDLE;
733
734 /* Mark physical channel as free */
735 if (s3cchan->phy)
736 s3c24xx_dma_phy_free(s3cchan);
737
738 /* Dequeue current job */
739 if (s3cchan->at) {
740 s3c24xx_dma_desc_free(&s3cchan->at->vd);
741 s3cchan->at = NULL;
742 }
743
744 /* Dequeue jobs not yet fired as well */
745 s3c24xx_dma_free_txd_list(s3cdma, s3cchan);
746unlock:
747 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
748
749 return ret;
750}
751
752static void s3c24xx_dma_free_chan_resources(struct dma_chan *chan)
753{
754 /* Ensure all queued descriptors are freed */
755 vchan_free_chan_resources(to_virt_chan(chan));
756}
757
758static enum dma_status s3c24xx_dma_tx_status(struct dma_chan *chan,
759 dma_cookie_t cookie, struct dma_tx_state *txstate)
760{
761 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
762 struct s3c24xx_txd *txd;
763 struct s3c24xx_sg *dsg;
764 struct virt_dma_desc *vd;
765 unsigned long flags;
766 enum dma_status ret;
767 size_t bytes = 0;
768
769 spin_lock_irqsave(&s3cchan->vc.lock, flags);
770 ret = dma_cookie_status(chan, cookie, txstate);
771 if (ret == DMA_COMPLETE) {
772 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
773 return ret;
774 }
775
776 /*
777 * There's no point calculating the residue if there's
778 * no txstate to store the value.
779 */
780 if (!txstate) {
781 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
782 return ret;
783 }
784
785 vd = vchan_find_desc(&s3cchan->vc, cookie);
786 if (vd) {
787 /* On the issued list, so hasn't been processed yet */
788 txd = to_s3c24xx_txd(&vd->tx);
789
790 list_for_each_entry(dsg, &txd->dsg_list, node)
791 bytes += dsg->len;
792 } else {
793 /*
794 * Currently running, so sum over the pending sg's and
795 * the currently active one.
796 */
797 txd = s3cchan->at;
798
799 dsg = list_entry(txd->at, struct s3c24xx_sg, node);
800 list_for_each_entry_from(dsg, &txd->dsg_list, node)
801 bytes += dsg->len;
802
803 bytes += s3c24xx_dma_getbytes_chan(s3cchan);
804 }
805 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
806
807 /*
808 * This cookie not complete yet
809 * Get number of bytes left in the active transactions and queue
810 */
811 dma_set_residue(txstate, bytes);
812
813 /* Whether waiting or running, we're in progress */
814 return ret;
815}
816
817/*
818 * Initialize a descriptor to be used by memcpy submit
819 */
820static struct dma_async_tx_descriptor *s3c24xx_dma_prep_memcpy(
821 struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
822 size_t len, unsigned long flags)
823{
824 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
825 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
826 struct s3c24xx_txd *txd;
827 struct s3c24xx_sg *dsg;
828 int src_mod, dest_mod;
829
830 dev_dbg(&s3cdma->pdev->dev, "prepare memcpy of %d bytes from %s\n",
831 len, s3cchan->name);
832
833 if ((len & S3C24XX_DCON_TC_MASK) != len) {
834 dev_err(&s3cdma->pdev->dev, "memcpy size %d to large\n", len);
835 return NULL;
836 }
837
838 txd = s3c24xx_dma_get_txd();
839 if (!txd)
840 return NULL;
841
842 dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
843 if (!dsg) {
844 s3c24xx_dma_free_txd(txd);
845 return NULL;
846 }
847 list_add_tail(&dsg->node, &txd->dsg_list);
848
849 dsg->src_addr = src;
850 dsg->dst_addr = dest;
851 dsg->len = len;
852
853 /*
854 * Determine a suitable transfer width.
855 * The DMA controller cannot fetch/store information which is not
856 * naturally aligned on the bus, i.e., a 4 byte fetch must start at
857 * an address divisible by 4 - more generally addr % width must be 0.
858 */
859 src_mod = src % 4;
860 dest_mod = dest % 4;
861 switch (len % 4) {
862 case 0:
863 txd->width = (src_mod == 0 && dest_mod == 0) ? 4 : 1;
864 break;
865 case 2:
866 txd->width = ((src_mod == 2 || src_mod == 0) &&
867 (dest_mod == 2 || dest_mod == 0)) ? 2 : 1;
868 break;
869 default:
870 txd->width = 1;
871 break;
872 }
873
874 txd->disrcc = S3C24XX_DISRCC_LOC_AHB | S3C24XX_DISRCC_INC_INCREMENT;
875 txd->didstc = S3C24XX_DIDSTC_LOC_AHB | S3C24XX_DIDSTC_INC_INCREMENT;
876 txd->dcon |= S3C24XX_DCON_DEMAND | S3C24XX_DCON_SYNC_HCLK |
877 S3C24XX_DCON_SERV_WHOLE;
878
879 return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
880}
881
882static struct dma_async_tx_descriptor *s3c24xx_dma_prep_dma_cyclic(
883 struct dma_chan *chan, dma_addr_t addr, size_t size, size_t period,
884 enum dma_transfer_direction direction, unsigned long flags)
885{
886 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
887 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
888 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
889 struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
890 struct s3c24xx_txd *txd;
891 struct s3c24xx_sg *dsg;
892 unsigned sg_len;
893 dma_addr_t slave_addr;
894 u32 hwcfg = 0;
895 int i;
896
897 dev_dbg(&s3cdma->pdev->dev,
898 "prepare cyclic transaction of %zu bytes with period %zu from %s\n",
899 size, period, s3cchan->name);
900
901 if (!is_slave_direction(direction)) {
902 dev_err(&s3cdma->pdev->dev,
903 "direction %d unsupported\n", direction);
904 return NULL;
905 }
906
907 txd = s3c24xx_dma_get_txd();
908 if (!txd)
909 return NULL;
910
911 txd->cyclic = 1;
912
913 if (cdata->handshake)
914 txd->dcon |= S3C24XX_DCON_HANDSHAKE;
915
916 switch (cdata->bus) {
917 case S3C24XX_DMA_APB:
918 txd->dcon |= S3C24XX_DCON_SYNC_PCLK;
919 hwcfg |= S3C24XX_DISRCC_LOC_APB;
920 break;
921 case S3C24XX_DMA_AHB:
922 txd->dcon |= S3C24XX_DCON_SYNC_HCLK;
923 hwcfg |= S3C24XX_DISRCC_LOC_AHB;
924 break;
925 }
926
927 /*
928 * Always assume our peripheral desintation is a fixed
929 * address in memory.
930 */
931 hwcfg |= S3C24XX_DISRCC_INC_FIXED;
932
933 /*
934 * Individual dma operations are requested by the slave,
935 * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE).
936 */
937 txd->dcon |= S3C24XX_DCON_SERV_SINGLE;
938
939 if (direction == DMA_MEM_TO_DEV) {
940 txd->disrcc = S3C24XX_DISRCC_LOC_AHB |
941 S3C24XX_DISRCC_INC_INCREMENT;
942 txd->didstc = hwcfg;
943 slave_addr = s3cchan->cfg.dst_addr;
944 txd->width = s3cchan->cfg.dst_addr_width;
945 } else {
946 txd->disrcc = hwcfg;
947 txd->didstc = S3C24XX_DIDSTC_LOC_AHB |
948 S3C24XX_DIDSTC_INC_INCREMENT;
949 slave_addr = s3cchan->cfg.src_addr;
950 txd->width = s3cchan->cfg.src_addr_width;
951 }
952
953 sg_len = size / period;
954
955 for (i = 0; i < sg_len; i++) {
956 dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
957 if (!dsg) {
958 s3c24xx_dma_free_txd(txd);
959 return NULL;
960 }
961 list_add_tail(&dsg->node, &txd->dsg_list);
962
963 dsg->len = period;
964 /* Check last period length */
965 if (i == sg_len - 1)
966 dsg->len = size - period * i;
967 if (direction == DMA_MEM_TO_DEV) {
968 dsg->src_addr = addr + period * i;
969 dsg->dst_addr = slave_addr;
970 } else { /* DMA_DEV_TO_MEM */
971 dsg->src_addr = slave_addr;
972 dsg->dst_addr = addr + period * i;
973 }
974 }
975
976 return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
977}
978
979static struct dma_async_tx_descriptor *s3c24xx_dma_prep_slave_sg(
980 struct dma_chan *chan, struct scatterlist *sgl,
981 unsigned int sg_len, enum dma_transfer_direction direction,
982 unsigned long flags, void *context)
983{
984 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
985 struct s3c24xx_dma_engine *s3cdma = s3cchan->host;
986 const struct s3c24xx_dma_platdata *pdata = s3cdma->pdata;
987 struct s3c24xx_dma_channel *cdata = &pdata->channels[s3cchan->id];
988 struct s3c24xx_txd *txd;
989 struct s3c24xx_sg *dsg;
990 struct scatterlist *sg;
991 dma_addr_t slave_addr;
992 u32 hwcfg = 0;
993 int tmp;
994
995 dev_dbg(&s3cdma->pdev->dev, "prepare transaction of %d bytes from %s\n",
996 sg_dma_len(sgl), s3cchan->name);
997
998 txd = s3c24xx_dma_get_txd();
999 if (!txd)
1000 return NULL;
1001
1002 if (cdata->handshake)
1003 txd->dcon |= S3C24XX_DCON_HANDSHAKE;
1004
1005 switch (cdata->bus) {
1006 case S3C24XX_DMA_APB:
1007 txd->dcon |= S3C24XX_DCON_SYNC_PCLK;
1008 hwcfg |= S3C24XX_DISRCC_LOC_APB;
1009 break;
1010 case S3C24XX_DMA_AHB:
1011 txd->dcon |= S3C24XX_DCON_SYNC_HCLK;
1012 hwcfg |= S3C24XX_DISRCC_LOC_AHB;
1013 break;
1014 }
1015
1016 /*
1017 * Always assume our peripheral desintation is a fixed
1018 * address in memory.
1019 */
1020 hwcfg |= S3C24XX_DISRCC_INC_FIXED;
1021
1022 /*
1023 * Individual dma operations are requested by the slave,
1024 * so serve only single atomic operations (S3C24XX_DCON_SERV_SINGLE).
1025 */
1026 txd->dcon |= S3C24XX_DCON_SERV_SINGLE;
1027
1028 if (direction == DMA_MEM_TO_DEV) {
1029 txd->disrcc = S3C24XX_DISRCC_LOC_AHB |
1030 S3C24XX_DISRCC_INC_INCREMENT;
1031 txd->didstc = hwcfg;
1032 slave_addr = s3cchan->cfg.dst_addr;
1033 txd->width = s3cchan->cfg.dst_addr_width;
1034 } else if (direction == DMA_DEV_TO_MEM) {
1035 txd->disrcc = hwcfg;
1036 txd->didstc = S3C24XX_DIDSTC_LOC_AHB |
1037 S3C24XX_DIDSTC_INC_INCREMENT;
1038 slave_addr = s3cchan->cfg.src_addr;
1039 txd->width = s3cchan->cfg.src_addr_width;
1040 } else {
1041 s3c24xx_dma_free_txd(txd);
1042 dev_err(&s3cdma->pdev->dev,
1043 "direction %d unsupported\n", direction);
1044 return NULL;
1045 }
1046
1047 for_each_sg(sgl, sg, sg_len, tmp) {
1048 dsg = kzalloc(sizeof(*dsg), GFP_NOWAIT);
1049 if (!dsg) {
1050 s3c24xx_dma_free_txd(txd);
1051 return NULL;
1052 }
1053 list_add_tail(&dsg->node, &txd->dsg_list);
1054
1055 dsg->len = sg_dma_len(sg);
1056 if (direction == DMA_MEM_TO_DEV) {
1057 dsg->src_addr = sg_dma_address(sg);
1058 dsg->dst_addr = slave_addr;
1059 } else { /* DMA_DEV_TO_MEM */
1060 dsg->src_addr = slave_addr;
1061 dsg->dst_addr = sg_dma_address(sg);
1062 }
1063 }
1064
1065 return vchan_tx_prep(&s3cchan->vc, &txd->vd, flags);
1066}
1067
1068/*
1069 * Slave transactions callback to the slave device to allow
1070 * synchronization of slave DMA signals with the DMAC enable
1071 */
1072static void s3c24xx_dma_issue_pending(struct dma_chan *chan)
1073{
1074 struct s3c24xx_dma_chan *s3cchan = to_s3c24xx_dma_chan(chan);
1075 unsigned long flags;
1076
1077 spin_lock_irqsave(&s3cchan->vc.lock, flags);
1078 if (vchan_issue_pending(&s3cchan->vc)) {
1079 if (!s3cchan->phy && s3cchan->state != S3C24XX_DMA_CHAN_WAITING)
1080 s3c24xx_dma_phy_alloc_and_start(s3cchan);
1081 }
1082 spin_unlock_irqrestore(&s3cchan->vc.lock, flags);
1083}
1084
1085/*
1086 * Bringup and teardown
1087 */
1088
1089/*
1090 * Initialise the DMAC memcpy/slave channels.
1091 * Make a local wrapper to hold required data
1092 */
1093static int s3c24xx_dma_init_virtual_channels(struct s3c24xx_dma_engine *s3cdma,
1094 struct dma_device *dmadev, unsigned int channels, bool slave)
1095{
1096 struct s3c24xx_dma_chan *chan;
1097 int i;
1098
1099 INIT_LIST_HEAD(&dmadev->channels);
1100
1101 /*
1102 * Register as many many memcpy as we have physical channels,
1103 * we won't always be able to use all but the code will have
1104 * to cope with that situation.
1105 */
1106 for (i = 0; i < channels; i++) {
1107 chan = devm_kzalloc(dmadev->dev, sizeof(*chan), GFP_KERNEL);
1108 if (!chan) {
1109 dev_err(dmadev->dev,
1110 "%s no memory for channel\n", __func__);
1111 return -ENOMEM;
1112 }
1113
1114 chan->id = i;
1115 chan->host = s3cdma;
1116 chan->state = S3C24XX_DMA_CHAN_IDLE;
1117
1118 if (slave) {
1119 chan->slave = true;
1120 chan->name = kasprintf(GFP_KERNEL, "slave%d", i);
1121 if (!chan->name)
1122 return -ENOMEM;
1123 } else {
1124 chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i);
1125 if (!chan->name)
1126 return -ENOMEM;
1127 }
1128 dev_dbg(dmadev->dev,
1129 "initialize virtual channel \"%s\"\n",
1130 chan->name);
1131
1132 chan->vc.desc_free = s3c24xx_dma_desc_free;
1133 vchan_init(&chan->vc, dmadev);
1134 }
1135 dev_info(dmadev->dev, "initialized %d virtual %s channels\n",
1136 i, slave ? "slave" : "memcpy");
1137 return i;
1138}
1139
1140static void s3c24xx_dma_free_virtual_channels(struct dma_device *dmadev)
1141{
1142 struct s3c24xx_dma_chan *chan = NULL;
1143 struct s3c24xx_dma_chan *next;
1144
1145 list_for_each_entry_safe(chan,
1146 next, &dmadev->channels, vc.chan.device_node)
1147 list_del(&chan->vc.chan.device_node);
1148}
1149
1150/* s3c2410, s3c2440 and s3c2442 have a 0x40 stride without separate clocks */
1151static struct soc_data soc_s3c2410 = {
1152 .stride = 0x40,
1153 .has_reqsel = false,
1154 .has_clocks = false,
1155};
1156
1157/* s3c2412 and s3c2413 have a 0x40 stride and dmareqsel mechanism */
1158static struct soc_data soc_s3c2412 = {
1159 .stride = 0x40,
1160 .has_reqsel = true,
1161 .has_clocks = true,
1162};
1163
1164/* s3c2443 and following have a 0x100 stride and dmareqsel mechanism */
1165static struct soc_data soc_s3c2443 = {
1166 .stride = 0x100,
1167 .has_reqsel = true,
1168 .has_clocks = true,
1169};
1170
1171static const struct platform_device_id s3c24xx_dma_driver_ids[] = {
1172 {
1173 .name = "s3c2410-dma",
1174 .driver_data = (kernel_ulong_t)&soc_s3c2410,
1175 }, {
1176 .name = "s3c2412-dma",
1177 .driver_data = (kernel_ulong_t)&soc_s3c2412,
1178 }, {
1179 .name = "s3c2443-dma",
1180 .driver_data = (kernel_ulong_t)&soc_s3c2443,
1181 },
1182 { },
1183};
1184
1185static struct soc_data *s3c24xx_dma_get_soc_data(struct platform_device *pdev)
1186{
1187 return (struct soc_data *)
1188 platform_get_device_id(pdev)->driver_data;
1189}
1190
1191static int s3c24xx_dma_probe(struct platform_device *pdev)
1192{
1193 const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev);
1194 struct s3c24xx_dma_engine *s3cdma;
1195 struct soc_data *sdata;
1196 struct resource *res;
1197 int ret;
1198 int i;
1199
1200 if (!pdata) {
1201 dev_err(&pdev->dev, "platform data missing\n");
1202 return -ENODEV;
1203 }
1204
1205 /* Basic sanity check */
1206 if (pdata->num_phy_channels > MAX_DMA_CHANNELS) {
1207 dev_err(&pdev->dev, "to many dma channels %d, max %d\n",
1208 pdata->num_phy_channels, MAX_DMA_CHANNELS);
1209 return -EINVAL;
1210 }
1211
1212 sdata = s3c24xx_dma_get_soc_data(pdev);
1213 if (!sdata)
1214 return -EINVAL;
1215
1216 s3cdma = devm_kzalloc(&pdev->dev, sizeof(*s3cdma), GFP_KERNEL);
1217 if (!s3cdma)
1218 return -ENOMEM;
1219
1220 s3cdma->pdev = pdev;
1221 s3cdma->pdata = pdata;
1222 s3cdma->sdata = sdata;
1223
1224 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1225 s3cdma->base = devm_ioremap_resource(&pdev->dev, res);
1226 if (IS_ERR(s3cdma->base))
1227 return PTR_ERR(s3cdma->base);
1228
1229 s3cdma->phy_chans = devm_kzalloc(&pdev->dev,
1230 sizeof(struct s3c24xx_dma_phy) *
1231 pdata->num_phy_channels,
1232 GFP_KERNEL);
1233 if (!s3cdma->phy_chans)
1234 return -ENOMEM;
1235
1236 /* acquire irqs and clocks for all physical channels */
1237 for (i = 0; i < pdata->num_phy_channels; i++) {
1238 struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
1239 char clk_name[6];
1240
1241 phy->id = i;
1242 phy->base = s3cdma->base + (i * sdata->stride);
1243 phy->host = s3cdma;
1244
1245 phy->irq = platform_get_irq(pdev, i);
1246 if (phy->irq < 0) {
1247 dev_err(&pdev->dev, "failed to get irq %d, err %d\n",
1248 i, phy->irq);
1249 continue;
1250 }
1251
1252 ret = devm_request_irq(&pdev->dev, phy->irq, s3c24xx_dma_irq,
1253 0, pdev->name, phy);
1254 if (ret) {
1255 dev_err(&pdev->dev, "Unable to request irq for channel %d, error %d\n",
1256 i, ret);
1257 continue;
1258 }
1259
1260 if (sdata->has_clocks) {
1261 sprintf(clk_name, "dma.%d", i);
1262 phy->clk = devm_clk_get(&pdev->dev, clk_name);
1263 if (IS_ERR(phy->clk) && sdata->has_clocks) {
1264 dev_err(&pdev->dev, "unable to acquire clock for channel %d, error %lu\n",
1265 i, PTR_ERR(phy->clk));
1266 continue;
1267 }
1268
1269 ret = clk_prepare(phy->clk);
1270 if (ret) {
1271 dev_err(&pdev->dev, "clock for phy %d failed, error %d\n",
1272 i, ret);
1273 continue;
1274 }
1275 }
1276
1277 spin_lock_init(&phy->lock);
1278 phy->valid = true;
1279
1280 dev_dbg(&pdev->dev, "physical channel %d is %s\n",
1281 i, s3c24xx_dma_phy_busy(phy) ? "BUSY" : "FREE");
1282 }
1283
1284 /* Initialize memcpy engine */
1285 dma_cap_set(DMA_MEMCPY, s3cdma->memcpy.cap_mask);
1286 dma_cap_set(DMA_PRIVATE, s3cdma->memcpy.cap_mask);
1287 s3cdma->memcpy.dev = &pdev->dev;
1288 s3cdma->memcpy.device_free_chan_resources =
1289 s3c24xx_dma_free_chan_resources;
1290 s3cdma->memcpy.device_prep_dma_memcpy = s3c24xx_dma_prep_memcpy;
1291 s3cdma->memcpy.device_tx_status = s3c24xx_dma_tx_status;
1292 s3cdma->memcpy.device_issue_pending = s3c24xx_dma_issue_pending;
1293 s3cdma->memcpy.device_config = s3c24xx_dma_set_runtime_config;
1294 s3cdma->memcpy.device_terminate_all = s3c24xx_dma_terminate_all;
1295
1296 /* Initialize slave engine for SoC internal dedicated peripherals */
1297 dma_cap_set(DMA_SLAVE, s3cdma->slave.cap_mask);
1298 dma_cap_set(DMA_CYCLIC, s3cdma->slave.cap_mask);
1299 dma_cap_set(DMA_PRIVATE, s3cdma->slave.cap_mask);
1300 s3cdma->slave.dev = &pdev->dev;
1301 s3cdma->slave.device_free_chan_resources =
1302 s3c24xx_dma_free_chan_resources;
1303 s3cdma->slave.device_tx_status = s3c24xx_dma_tx_status;
1304 s3cdma->slave.device_issue_pending = s3c24xx_dma_issue_pending;
1305 s3cdma->slave.device_prep_slave_sg = s3c24xx_dma_prep_slave_sg;
1306 s3cdma->slave.device_prep_dma_cyclic = s3c24xx_dma_prep_dma_cyclic;
1307 s3cdma->slave.device_config = s3c24xx_dma_set_runtime_config;
1308 s3cdma->slave.device_terminate_all = s3c24xx_dma_terminate_all;
1309
1310 /* Register as many memcpy channels as there are physical channels */
1311 ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->memcpy,
1312 pdata->num_phy_channels, false);
1313 if (ret <= 0) {
1314 dev_warn(&pdev->dev,
1315 "%s failed to enumerate memcpy channels - %d\n",
1316 __func__, ret);
1317 goto err_memcpy;
1318 }
1319
1320 /* Register slave channels */
1321 ret = s3c24xx_dma_init_virtual_channels(s3cdma, &s3cdma->slave,
1322 pdata->num_channels, true);
1323 if (ret <= 0) {
1324 dev_warn(&pdev->dev,
1325 "%s failed to enumerate slave channels - %d\n",
1326 __func__, ret);
1327 goto err_slave;
1328 }
1329
1330 ret = dma_async_device_register(&s3cdma->memcpy);
1331 if (ret) {
1332 dev_warn(&pdev->dev,
1333 "%s failed to register memcpy as an async device - %d\n",
1334 __func__, ret);
1335 goto err_memcpy_reg;
1336 }
1337
1338 ret = dma_async_device_register(&s3cdma->slave);
1339 if (ret) {
1340 dev_warn(&pdev->dev,
1341 "%s failed to register slave as an async device - %d\n",
1342 __func__, ret);
1343 goto err_slave_reg;
1344 }
1345
1346 platform_set_drvdata(pdev, s3cdma);
1347 dev_info(&pdev->dev, "Loaded dma driver with %d physical channels\n",
1348 pdata->num_phy_channels);
1349
1350 return 0;
1351
1352err_slave_reg:
1353 dma_async_device_unregister(&s3cdma->memcpy);
1354err_memcpy_reg:
1355 s3c24xx_dma_free_virtual_channels(&s3cdma->slave);
1356err_slave:
1357 s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy);
1358err_memcpy:
1359 if (sdata->has_clocks)
1360 for (i = 0; i < pdata->num_phy_channels; i++) {
1361 struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
1362 if (phy->valid)
1363 clk_unprepare(phy->clk);
1364 }
1365
1366 return ret;
1367}
1368
1369static int s3c24xx_dma_remove(struct platform_device *pdev)
1370{
1371 const struct s3c24xx_dma_platdata *pdata = dev_get_platdata(&pdev->dev);
1372 struct s3c24xx_dma_engine *s3cdma = platform_get_drvdata(pdev);
1373 struct soc_data *sdata = s3c24xx_dma_get_soc_data(pdev);
1374 int i;
1375
1376 dma_async_device_unregister(&s3cdma->slave);
1377 dma_async_device_unregister(&s3cdma->memcpy);
1378
1379 s3c24xx_dma_free_virtual_channels(&s3cdma->slave);
1380 s3c24xx_dma_free_virtual_channels(&s3cdma->memcpy);
1381
1382 if (sdata->has_clocks)
1383 for (i = 0; i < pdata->num_phy_channels; i++) {
1384 struct s3c24xx_dma_phy *phy = &s3cdma->phy_chans[i];
1385 if (phy->valid)
1386 clk_unprepare(phy->clk);
1387 }
1388
1389 return 0;
1390}
1391
1392static struct platform_driver s3c24xx_dma_driver = {
1393 .driver = {
1394 .name = "s3c24xx-dma",
1395 },
1396 .id_table = s3c24xx_dma_driver_ids,
1397 .probe = s3c24xx_dma_probe,
1398 .remove = s3c24xx_dma_remove,
1399};
1400
1401module_platform_driver(s3c24xx_dma_driver);
1402
1403bool s3c24xx_dma_filter(struct dma_chan *chan, void *param)
1404{
1405 struct s3c24xx_dma_chan *s3cchan;
1406
1407 if (chan->device->dev->driver != &s3c24xx_dma_driver.driver)
1408 return false;
1409
1410 s3cchan = to_s3c24xx_dma_chan(chan);
1411
1412 return s3cchan->id == (int)param;
1413}
1414EXPORT_SYMBOL(s3c24xx_dma_filter);
1415
1416MODULE_DESCRIPTION("S3C24XX DMA Driver");
1417MODULE_AUTHOR("Heiko Stuebner");
1418MODULE_LICENSE("GPL v2");