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mxc: mx1/mx2 DMA: add a possibility to create an endless DMA transfer
[deliverable/linux.git] / arch / arm / plat-mxc / dma-mx1-mx2.c
CommitLineData
58a85f46
SH		 1/*
2 * linux/arch/arm/plat-mxc/dma-mx1-mx2.c
3 *
4 * i.MX DMA registration and IRQ dispatching
5 *
6 * Copyright 2006 Pavel Pisa <pisa@cmp.felk.cvut.cz>
7 * Copyright 2008 Juergen Beisert, <kernel@pengutronix.de>
8 * Copyright 2008 Sascha Hauer, <s.hauer@pengutronix.de>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
22 * MA 02110-1301, USA.
23 */
24
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/kernel.h>
28#include <linux/interrupt.h>
29#include <linux/errno.h>
30#include <linux/clk.h>
31#include <linux/scatterlist.h>
32#include <linux/io.h>
33
34#include <asm/system.h>
35#include <asm/irq.h>
36#include <mach/hardware.h>
58a85f46
SH		 37#include <mach/dma-mx1-mx2.h>
38
39#define DMA_DCR 0x00 /* Control Register */
40#define DMA_DISR 0x04 /* Interrupt status Register */
41#define DMA_DIMR 0x08 /* Interrupt mask Register */
42#define DMA_DBTOSR 0x0c /* Burst timeout status Register */
43#define DMA_DRTOSR 0x10 /* Request timeout Register */
44#define DMA_DSESR 0x14 /* Transfer Error Status Register */
45#define DMA_DBOSR 0x18 /* Buffer overflow status Register */
46#define DMA_DBTOCR 0x1c /* Burst timeout control Register */
47#define DMA_WSRA 0x40 /* W-Size Register A */
48#define DMA_XSRA 0x44 /* X-Size Register A */
49#define DMA_YSRA 0x48 /* Y-Size Register A */
50#define DMA_WSRB 0x4c /* W-Size Register B */
51#define DMA_XSRB 0x50 /* X-Size Register B */
52#define DMA_YSRB 0x54 /* Y-Size Register B */
53#define DMA_SAR(x) (0x80 + ((x) << 6)) /* Source Address Registers */
54#define DMA_DAR(x) (0x84 + ((x) << 6)) /* Destination Address Registers */
55#define DMA_CNTR(x) (0x88 + ((x) << 6)) /* Count Registers */
56#define DMA_CCR(x) (0x8c + ((x) << 6)) /* Control Registers */
57#define DMA_RSSR(x) (0x90 + ((x) << 6)) /* Request source select Registers */
58#define DMA_BLR(x) (0x94 + ((x) << 6)) /* Burst length Registers */
59#define DMA_RTOR(x) (0x98 + ((x) << 6)) /* Request timeout Registers */
60#define DMA_BUCR(x) (0x98 + ((x) << 6)) /* Bus Utilization Registers */
61#define DMA_CCNR(x) (0x9C + ((x) << 6)) /* Channel counter Registers */
62
63#define DCR_DRST (1<<1)
64#define DCR_DEN (1<<0)
65#define DBTOCR_EN (1<<15)
66#define DBTOCR_CNT(x) ((x) & 0x7fff)
67#define CNTR_CNT(x) ((x) & 0xffffff)
68#define CCR_ACRPT (1<<14)
69#define CCR_DMOD_LINEAR (0x0 << 12)
70#define CCR_DMOD_2D (0x1 << 12)
71#define CCR_DMOD_FIFO (0x2 << 12)
72#define CCR_DMOD_EOBFIFO (0x3 << 12)
73#define CCR_SMOD_LINEAR (0x0 << 10)
74#define CCR_SMOD_2D (0x1 << 10)
75#define CCR_SMOD_FIFO (0x2 << 10)
76#define CCR_SMOD_EOBFIFO (0x3 << 10)
77#define CCR_MDIR_DEC (1<<9)
78#define CCR_MSEL_B (1<<8)
79#define CCR_DSIZ_32 (0x0 << 6)
80#define CCR_DSIZ_8 (0x1 << 6)
81#define CCR_DSIZ_16 (0x2 << 6)
82#define CCR_SSIZ_32 (0x0 << 4)
83#define CCR_SSIZ_8 (0x1 << 4)
84#define CCR_SSIZ_16 (0x2 << 4)
85#define CCR_REN (1<<3)
86#define CCR_RPT (1<<2)
87#define CCR_FRC (1<<1)
88#define CCR_CEN (1<<0)
89#define RTOR_EN (1<<15)
90#define RTOR_CLK (1<<14)
91#define RTOR_PSC (1<<13)
92
93/*
94 * struct imx_dma_channel - i.MX specific DMA extension
95 * @name: name specified by DMA client
96 * @irq_handler: client callback for end of transfer
97 * @err_handler: client callback for error condition
98 * @data: clients context data for callbacks
99 * @dma_mode: direction of the transfer %DMA_MODE_READ or %DMA_MODE_WRITE
100 * @sg: pointer to the actual read/written chunk for scatter-gather emulation
101 * @resbytes: total residual number of bytes to transfer
102 * (it can be lower or same as sum of SG mapped chunk sizes)
103 * @sgcount: number of chunks to be read/written
104 *
105 * Structure is used for IMX DMA processing. It would be probably good
106 * @struct dma_struct in the future for external interfacing and use
107 * @struct imx_dma_channel only as extension to it.
108 */
109
110struct imx_dma_channel {
111 const char *name;
112 void (*irq_handler) (int, void *);
113 void (*err_handler) (int, void *, int errcode);
114 void (*prog_handler) (int, void *, struct scatterlist *);
115 void *data;
4e57ea9a 116 unsigned int dma_mode;
58a85f46
SH		 117 struct scatterlist *sg;
118 unsigned int resbytes;
119 int dma_num;
120
121 int in_use;
122
123 u32 ccr_from_device;
124 u32 ccr_to_device;
125
126 struct timer_list watchdog;
127
128 int hw_chaining;
129};
130
131static struct imx_dma_channel imx_dma_channels[IMX_DMA_CHANNELS];
132
133static struct clk *dma_clk;
134
135static int imx_dma_hw_chain(struct imx_dma_channel *imxdma)
136{
137 if (cpu_is_mx27())
138 return imxdma->hw_chaining;
139 else
140 return 0;
141}
142
143
144/*
145 * imx_dma_sg_next - prepare next chunk for scatter-gather DMA emulation
146 */
147static inline int imx_dma_sg_next(int channel, struct scatterlist *sg)
148{
149 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
150 unsigned long now;
151
152 if (!imxdma->name) {
153 printk(KERN_CRIT "%s: called for not allocated channel %d\n",
154 __func__, channel);
155 return 0;
156 }
157
158 now = min(imxdma->resbytes, sg->length);
4998f1a3
SH		 159 if (imxdma->resbytes != IMX_DMA_LENGTH_LOOP)
160 imxdma->resbytes -= now;
58a85f46
SH		 161
162 if ((imxdma->dma_mode & DMA_MODE_MASK) == DMA_MODE_READ)
163 __raw_writel(sg->dma_address, DMA_BASE + DMA_DAR(channel));
164 else
165 __raw_writel(sg->dma_address, DMA_BASE + DMA_SAR(channel));
166
167 __raw_writel(now, DMA_BASE + DMA_CNTR(channel));
168
169 pr_debug("imxdma%d: next sg chunk dst 0x%08x, src 0x%08x, "
170 "size 0x%08x\n", channel,
171 __raw_readl(DMA_BASE + DMA_DAR(channel)),
172 __raw_readl(DMA_BASE + DMA_SAR(channel)),
173 __raw_readl(DMA_BASE + DMA_CNTR(channel)));
174
175 return now;
176}
177
178/**
179 * imx_dma_setup_single - setup i.MX DMA channel for linear memory to/from
180 * device transfer
181 *
182 * @channel: i.MX DMA channel number
183 * @dma_address: the DMA/physical memory address of the linear data block
184 * to transfer
185 * @dma_length: length of the data block in bytes
186 * @dev_addr: physical device port address
187 * @dmamode: DMA transfer mode, %DMA_MODE_READ from the device to the memory
188 * or %DMA_MODE_WRITE from memory to the device
189 *
190 * Return value: if incorrect parameters are provided -%EINVAL.
191 * Zero indicates success.
192 */
193int
194imx_dma_setup_single(int channel, dma_addr_t dma_address,
195 unsigned int dma_length, unsigned int dev_addr,
33ebc19d 196 unsigned int dmamode)
58a85f46
SH		 197{
198 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
199
200 imxdma->sg = NULL;
201 imxdma->dma_mode = dmamode;
202
203 if (!dma_address) {
204 printk(KERN_ERR "imxdma%d: imx_dma_setup_single null address\n",
205 channel);
206 return -EINVAL;
207 }
208
209 if (!dma_length) {
210 printk(KERN_ERR "imxdma%d: imx_dma_setup_single zero length\n",
211 channel);
212 return -EINVAL;
213 }
214
215 if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) {
216 pr_debug("imxdma%d: %s dma_addressg=0x%08x dma_length=%d "
217 "dev_addr=0x%08x for read\n",
218 channel, __func__, (unsigned int)dma_address,
219 dma_length, dev_addr);
220
221 __raw_writel(dev_addr, DMA_BASE + DMA_SAR(channel));
222 __raw_writel(dma_address, DMA_BASE + DMA_DAR(channel));
223 __raw_writel(imxdma->ccr_from_device,
224 DMA_BASE + DMA_CCR(channel));
225 } else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) {
226 pr_debug("imxdma%d: %s dma_addressg=0x%08x dma_length=%d "
227 "dev_addr=0x%08x for write\n",
228 channel, __func__, (unsigned int)dma_address,
229 dma_length, dev_addr);
230
231 __raw_writel(dma_address, DMA_BASE + DMA_SAR(channel));
232 __raw_writel(dev_addr, DMA_BASE + DMA_DAR(channel));
233 __raw_writel(imxdma->ccr_to_device,
234 DMA_BASE + DMA_CCR(channel));
235 } else {
236 printk(KERN_ERR "imxdma%d: imx_dma_setup_single bad dmamode\n",
237 channel);
238 return -EINVAL;
239 }
240
241 __raw_writel(dma_length, DMA_BASE + DMA_CNTR(channel));
242
243 return 0;
244}
245EXPORT_SYMBOL(imx_dma_setup_single);
246
247/**
248 * imx_dma_setup_sg - setup i.MX DMA channel SG list to/from device transfer
249 * @channel: i.MX DMA channel number
250 * @sg: pointer to the scatter-gather list/vector
251 * @sgcount: scatter-gather list hungs count
252 * @dma_length: total length of the transfer request in bytes
253 * @dev_addr: physical device port address
254 * @dmamode: DMA transfer mode, %DMA_MODE_READ from the device to the memory
255 * or %DMA_MODE_WRITE from memory to the device
256 *
257 * The function sets up DMA channel state and registers to be ready for
258 * transfer specified by provided parameters. The scatter-gather emulation
259 * is set up according to the parameters.
260 *
261 * The full preparation of the transfer requires setup of more register
262 * by the caller before imx_dma_enable() can be called.
263 *
264 * %BLR(channel) holds transfer burst length in bytes, 0 means 64 bytes
265 *
266 * %RSSR(channel) has to be set to the DMA request line source %DMA_REQ_xxx
267 *
268 * %CCR(channel) has to specify transfer parameters, the next settings is
269 * typical for linear or simple scatter-gather transfers if %DMA_MODE_READ is
270 * specified
271 *
272 * %CCR_DMOD_LINEAR | %CCR_DSIZ_32 | %CCR_SMOD_FIFO | %CCR_SSIZ_x
273 *
274 * The typical setup for %DMA_MODE_WRITE is specified by next options
275 * combination
276 *
277 * %CCR_SMOD_LINEAR | %CCR_SSIZ_32 | %CCR_DMOD_FIFO | %CCR_DSIZ_x
278 *
279 * Be careful here and do not mistakenly mix source and target device
280 * port sizes constants, they are really different:
281 * %CCR_SSIZ_8, %CCR_SSIZ_16, %CCR_SSIZ_32,
282 * %CCR_DSIZ_8, %CCR_DSIZ_16, %CCR_DSIZ_32
283 *
284 * Return value: if incorrect parameters are provided -%EINVAL.
285 * Zero indicates success.
286 */
287int
288imx_dma_setup_sg(int channel,
289 struct scatterlist *sg, unsigned int sgcount,
290 unsigned int dma_length, unsigned int dev_addr,
33ebc19d 291 unsigned int dmamode)
58a85f46
SH		 292{
293 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
294
295 if (imxdma->in_use)
296 return -EBUSY;
297
298 imxdma->sg = sg;
299 imxdma->dma_mode = dmamode;
300 imxdma->resbytes = dma_length;
301
302 if (!sg || !sgcount) {
303 printk(KERN_ERR "imxdma%d: imx_dma_setup_sg epty sg list\n",
304 channel);
305 return -EINVAL;
306 }
307
308 if (!sg->length) {
309 printk(KERN_ERR "imxdma%d: imx_dma_setup_sg zero length\n",
310 channel);
311 return -EINVAL;
312 }
313
314 if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) {
315 pr_debug("imxdma%d: %s sg=%p sgcount=%d total length=%d "
316 "dev_addr=0x%08x for read\n",
317 channel, __func__, sg, sgcount, dma_length, dev_addr);
318
319 __raw_writel(dev_addr, DMA_BASE + DMA_SAR(channel));
320 __raw_writel(imxdma->ccr_from_device,
321 DMA_BASE + DMA_CCR(channel));
322 } else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) {
323 pr_debug("imxdma%d: %s sg=%p sgcount=%d total length=%d "
324 "dev_addr=0x%08x for write\n",
325 channel, __func__, sg, sgcount, dma_length, dev_addr);
326
327 __raw_writel(dev_addr, DMA_BASE + DMA_DAR(channel));
328 __raw_writel(imxdma->ccr_to_device,
329 DMA_BASE + DMA_CCR(channel));
330 } else {
331 printk(KERN_ERR "imxdma%d: imx_dma_setup_sg bad dmamode\n",
332 channel);
333 return -EINVAL;
334 }
335
336 imx_dma_sg_next(channel, sg);
337
338 return 0;
339}
340EXPORT_SYMBOL(imx_dma_setup_sg);
341
342int
343imx_dma_config_channel(int channel, unsigned int config_port,
344 unsigned int config_mem, unsigned int dmareq, int hw_chaining)
345{
346 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
347 u32 dreq = 0;
348
349 imxdma->hw_chaining = 0;
350
351 if (hw_chaining) {
352 imxdma->hw_chaining = 1;
353 if (!imx_dma_hw_chain(imxdma))
354 return -EINVAL;
355 }
356
357 if (dmareq)
358 dreq = CCR_REN;
359
360 imxdma->ccr_from_device = config_port | (config_mem << 2) | dreq;
361 imxdma->ccr_to_device = config_mem | (config_port << 2) | dreq;
362
363 __raw_writel(dmareq, DMA_BASE + DMA_RSSR(channel));
364
365 return 0;
366}
367EXPORT_SYMBOL(imx_dma_config_channel);
368
369void imx_dma_config_burstlen(int channel, unsigned int burstlen)
370{
371 __raw_writel(burstlen, DMA_BASE + DMA_BLR(channel));
372}
373EXPORT_SYMBOL(imx_dma_config_burstlen);
374
375/**
376 * imx_dma_setup_handlers - setup i.MX DMA channel end and error notification
377 * handlers
378 * @channel: i.MX DMA channel number
379 * @irq_handler: the pointer to the function called if the transfer
380 * ends successfully
381 * @err_handler: the pointer to the function called if the premature
382 * end caused by error occurs
383 * @data: user specified value to be passed to the handlers
384 */
385int
386imx_dma_setup_handlers(int channel,
387 void (*irq_handler) (int, void *),
388 void (*err_handler) (int, void *, int),
389 void *data)
390{
391 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
392 unsigned long flags;
393
394 if (!imxdma->name) {
395 printk(KERN_CRIT "%s: called for not allocated channel %d\n",
396 __func__, channel);
397 return -ENODEV;
398 }
399
400 local_irq_save(flags);
401 __raw_writel(1 << channel, DMA_BASE + DMA_DISR);
402 imxdma->irq_handler = irq_handler;
403 imxdma->err_handler = err_handler;
404 imxdma->data = data;
405 local_irq_restore(flags);
406 return 0;
407}
408EXPORT_SYMBOL(imx_dma_setup_handlers);
409
410/**
411 * imx_dma_setup_progression_handler - setup i.MX DMA channel progression
412 * handlers
413 * @channel: i.MX DMA channel number
414 * @prog_handler: the pointer to the function called if the transfer progresses
415 */
416int
417imx_dma_setup_progression_handler(int channel,
418 void (*prog_handler) (int, void*, struct scatterlist*))
419{
420 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
421 unsigned long flags;
422
423 if (!imxdma->name) {
424 printk(KERN_CRIT "%s: called for not allocated channel %d\n",
425 __func__, channel);
426 return -ENODEV;
427 }
428
429 local_irq_save(flags);
430 imxdma->prog_handler = prog_handler;
431 local_irq_restore(flags);
432 return 0;
433}
434EXPORT_SYMBOL(imx_dma_setup_progression_handler);
435
436/**
437 * imx_dma_enable - function to start i.MX DMA channel operation
438 * @channel: i.MX DMA channel number
439 *
440 * The channel has to be allocated by driver through imx_dma_request()
441 * or imx_dma_request_by_prio() function.
442 * The transfer parameters has to be set to the channel registers through
443 * call of the imx_dma_setup_single() or imx_dma_setup_sg() function
444 * and registers %BLR(channel), %RSSR(channel) and %CCR(channel) has to
445 * be set prior this function call by the channel user.
446 */
447void imx_dma_enable(int channel)
448{
449 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
450 unsigned long flags;
451
452 pr_debug("imxdma%d: imx_dma_enable\n", channel);
453
454 if (!imxdma->name) {
455 printk(KERN_CRIT "%s: called for not allocated channel %d\n",
456 __func__, channel);
457 return;
458 }
459
460 if (imxdma->in_use)
461 return;
462
463 local_irq_save(flags);
464
465 __raw_writel(1 << channel, DMA_BASE + DMA_DISR);
466 __raw_writel(__raw_readl(DMA_BASE + DMA_DIMR) & ~(1 << channel),
467 DMA_BASE + DMA_DIMR);
468 __raw_writel(__raw_readl(DMA_BASE + DMA_CCR(channel)) | CCR_CEN |
469 CCR_ACRPT,
470 DMA_BASE + DMA_CCR(channel));
471
472#ifdef CONFIG_ARCH_MX2
473 if (imxdma->sg && imx_dma_hw_chain(imxdma)) {
474 imxdma->sg = sg_next(imxdma->sg);
475 if (imxdma->sg) {
476 u32 tmp;
477 imx_dma_sg_next(channel, imxdma->sg);
478 tmp = __raw_readl(DMA_BASE + DMA_CCR(channel));
479 __raw_writel(tmp | CCR_RPT | CCR_ACRPT,
480 DMA_BASE + DMA_CCR(channel));
481 }
482 }
483#endif
484 imxdma->in_use = 1;
485
486 local_irq_restore(flags);
487}
488EXPORT_SYMBOL(imx_dma_enable);
489
490/**
491 * imx_dma_disable - stop, finish i.MX DMA channel operatin
492 * @channel: i.MX DMA channel number
493 */
494void imx_dma_disable(int channel)
495{
496 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
497 unsigned long flags;
498
499 pr_debug("imxdma%d: imx_dma_disable\n", channel);
500
501 if (imx_dma_hw_chain(imxdma))
502 del_timer(&imxdma->watchdog);
503
504 local_irq_save(flags);
505 __raw_writel(__raw_readl(DMA_BASE + DMA_DIMR) | (1 << channel),
506 DMA_BASE + DMA_DIMR);
507 __raw_writel(__raw_readl(DMA_BASE + DMA_CCR(channel)) & ~CCR_CEN,
508 DMA_BASE + DMA_CCR(channel));
509 __raw_writel(1 << channel, DMA_BASE + DMA_DISR);
510 imxdma->in_use = 0;
511 local_irq_restore(flags);
512}
513EXPORT_SYMBOL(imx_dma_disable);
514
7c995023 515#ifdef CONFIG_ARCH_MX2
58a85f46
SH		 516static void imx_dma_watchdog(unsigned long chno)
517{
518 struct imx_dma_channel *imxdma = &imx_dma_channels[chno];
519
520 __raw_writel(0, DMA_BASE + DMA_CCR(chno));
521 imxdma->in_use = 0;
522 imxdma->sg = NULL;
523
524 if (imxdma->err_handler)
525 imxdma->err_handler(chno, imxdma->data, IMX_DMA_ERR_TIMEOUT);
526}
7c995023 527#endif
58a85f46
SH		 528
529static irqreturn_t dma_err_handler(int irq, void *dev_id)
530{
531 int i, disr;
532 struct imx_dma_channel *imxdma;
533 unsigned int err_mask;
534 int errcode;
535
536 disr = __raw_readl(DMA_BASE + DMA_DISR);
537
538 err_mask = __raw_readl(DMA_BASE + DMA_DBTOSR) |
539 __raw_readl(DMA_BASE + DMA_DRTOSR) |
540 __raw_readl(DMA_BASE + DMA_DSESR) |
541 __raw_readl(DMA_BASE + DMA_DBOSR);
542
543 if (!err_mask)
544 return IRQ_HANDLED;
545
546 __raw_writel(disr & err_mask, DMA_BASE + DMA_DISR);
547
548 for (i = 0; i < IMX_DMA_CHANNELS; i++) {
549 if (!(err_mask & (1 << i)))
550 continue;
551 imxdma = &imx_dma_channels[i];
552 errcode = 0;
553
554 if (__raw_readl(DMA_BASE + DMA_DBTOSR) & (1 << i)) {
555 __raw_writel(1 << i, DMA_BASE + DMA_DBTOSR);
556 errcode |= IMX_DMA_ERR_BURST;
557 }
558 if (__raw_readl(DMA_BASE + DMA_DRTOSR) & (1 << i)) {
559 __raw_writel(1 << i, DMA_BASE + DMA_DRTOSR);
560 errcode |= IMX_DMA_ERR_REQUEST;
561 }
562 if (__raw_readl(DMA_BASE + DMA_DSESR) & (1 << i)) {
563 __raw_writel(1 << i, DMA_BASE + DMA_DSESR);
564 errcode |= IMX_DMA_ERR_TRANSFER;
565 }
566 if (__raw_readl(DMA_BASE + DMA_DBOSR) & (1 << i)) {
567 __raw_writel(1 << i, DMA_BASE + DMA_DBOSR);
568 errcode |= IMX_DMA_ERR_BUFFER;
569 }
570 if (imxdma->name && imxdma->err_handler) {
571 imxdma->err_handler(i, imxdma->data, errcode);
572 continue;
573 }
574
575 imx_dma_channels[i].sg = NULL;
576
577 printk(KERN_WARNING
578 "DMA timeout on channel %d (%s) -%s%s%s%s\n",
579 i, imxdma->name,
580 errcode & IMX_DMA_ERR_BURST ? " burst" : "",
581 errcode & IMX_DMA_ERR_REQUEST ? " request" : "",
582 errcode & IMX_DMA_ERR_TRANSFER ? " transfer" : "",
583 errcode & IMX_DMA_ERR_BUFFER ? " buffer" : "");
584 }
585 return IRQ_HANDLED;
586}
587
588static void dma_irq_handle_channel(int chno)
589{
590 struct imx_dma_channel *imxdma = &imx_dma_channels[chno];
591
592 if (!imxdma->name) {
593 /*
594 * IRQ for an unregistered DMA channel:
595 * let's clear the interrupts and disable it.
596 */
597 printk(KERN_WARNING
598 "spurious IRQ for DMA channel %d\n", chno);
599 return;
600 }
601
602 if (imxdma->sg) {
603 u32 tmp;
604 struct scatterlist *current_sg = imxdma->sg;
605 imxdma->sg = sg_next(imxdma->sg);
606
607 if (imxdma->sg) {
608 imx_dma_sg_next(chno, imxdma->sg);
609
610 tmp = __raw_readl(DMA_BASE + DMA_CCR(chno));
611
612 if (imx_dma_hw_chain(imxdma)) {
613 /* FIXME: The timeout should probably be
614 * configurable
615 */
616 mod_timer(&imxdma->watchdog,
617 jiffies + msecs_to_jiffies(500));
618
619 tmp |= CCR_CEN | CCR_RPT | CCR_ACRPT;
620 __raw_writel(tmp, DMA_BASE +
621 DMA_CCR(chno));
622 } else {
623 __raw_writel(tmp & ~CCR_CEN, DMA_BASE +
624 DMA_CCR(chno));
625 tmp |= CCR_CEN;
626 }
627
628 __raw_writel(tmp, DMA_BASE + DMA_CCR(chno));
629
630 if (imxdma->prog_handler)
631 imxdma->prog_handler(chno, imxdma->data,
632 current_sg);
633
634 return;
635 }
636
637 if (imx_dma_hw_chain(imxdma)) {
638 del_timer(&imxdma->watchdog);
639 return;
640 }
641 }
642
643 __raw_writel(0, DMA_BASE + DMA_CCR(chno));
644 imxdma->in_use = 0;
645 if (imxdma->irq_handler)
646 imxdma->irq_handler(chno, imxdma->data);
647}
648
649static irqreturn_t dma_irq_handler(int irq, void *dev_id)
650{
651 int i, disr;
652
653#ifdef CONFIG_ARCH_MX2
654 dma_err_handler(irq, dev_id);
655#endif
656
657 disr = __raw_readl(DMA_BASE + DMA_DISR);
658
659 pr_debug("imxdma: dma_irq_handler called, disr=0x%08x\n",
660 disr);
661
662 __raw_writel(disr, DMA_BASE + DMA_DISR);
663 for (i = 0; i < IMX_DMA_CHANNELS; i++) {
664 if (disr & (1 << i))
665 dma_irq_handle_channel(i);
666 }
667
668 return IRQ_HANDLED;
669}
670
671/**
672 * imx_dma_request - request/allocate specified channel number
673 * @channel: i.MX DMA channel number
674 * @name: the driver/caller own non-%NULL identification
675 */
676int imx_dma_request(int channel, const char *name)
677{
678 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
679 unsigned long flags;
7c995023 680 int ret = 0;
58a85f46
SH		 681
682 /* basic sanity checks */
683 if (!name)
684 return -EINVAL;
685
686 if (channel >= IMX_DMA_CHANNELS) {
687 printk(KERN_CRIT "%s: called for non-existed channel %d\n",
688 __func__, channel);
689 return -EINVAL;
690 }
691
692 local_irq_save(flags);
693 if (imxdma->name) {
694 local_irq_restore(flags);
695 return -EBUSY;
696 }
f2292532
MF		 697 memset(imxdma, 0, sizeof(imxdma));
698 imxdma->name = name;
699 local_irq_restore(flags); /* request_irq() can block */
58a85f46
SH		 700
701#ifdef CONFIG_ARCH_MX2
702 ret = request_irq(MXC_INT_DMACH0 + channel, dma_irq_handler, 0, "DMA",
703 NULL);
704 if (ret) {
f2292532 705 imxdma->name = NULL;
58a85f46
SH		 706 printk(KERN_CRIT "Can't register IRQ %d for DMA channel %d\n",
707 MXC_INT_DMACH0 + channel, channel);
708 return ret;
709 }
710 init_timer(&imxdma->watchdog);
711 imxdma->watchdog.function = &imx_dma_watchdog;
712 imxdma->watchdog.data = channel;
713#endif
714
7c995023 715 return ret;
58a85f46
SH		 716}
717EXPORT_SYMBOL(imx_dma_request);
718
719/**
720 * imx_dma_free - release previously acquired channel
721 * @channel: i.MX DMA channel number
722 */
723void imx_dma_free(int channel)
724{
725 unsigned long flags;
726 struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
727
728 if (!imxdma->name) {
729 printk(KERN_CRIT
730 "%s: trying to free free channel %d\n",
731 __func__, channel);
732 return;
733 }
734
735 local_irq_save(flags);
736 /* Disable interrupts */
de0096d8 737 imx_dma_disable(channel);
58a85f46
SH		 738 imxdma->name = NULL;
739
740#ifdef CONFIG_ARCH_MX2
741 free_irq(MXC_INT_DMACH0 + channel, NULL);
742#endif
743
744 local_irq_restore(flags);
745}
746EXPORT_SYMBOL(imx_dma_free);
747
748/**
749 * imx_dma_request_by_prio - find and request some of free channels best
750 * suiting requested priority
751 * @channel: i.MX DMA channel number
752 * @name: the driver/caller own non-%NULL identification
753 *
754 * This function tries to find a free channel in the specified priority group
755 * This function tries to find a free channel in the specified priority group
756 * if the priority cannot be achieved it tries to look for free channel
757 * in the higher and then even lower priority groups.
758 *
759 * Return value: If there is no free channel to allocate, -%ENODEV is returned.
760 * On successful allocation channel is returned.
761 */
762int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio)
763{
764 int i;
765 int best;
766
767 switch (prio) {
768 case (DMA_PRIO_HIGH):
769 best = 8;
770 break;
771 case (DMA_PRIO_MEDIUM):
772 best = 4;
773 break;
774 case (DMA_PRIO_LOW):
775 default:
776 best = 0;
777 break;
778 }
779
780 for (i = best; i < IMX_DMA_CHANNELS; i++)
781 if (!imx_dma_request(i, name))
782 return i;
783
784 for (i = best - 1; i >= 0; i--)
785 if (!imx_dma_request(i, name))
786 return i;
787
788 printk(KERN_ERR "%s: no free DMA channel found\n", __func__);
789
790 return -ENODEV;
791}
792EXPORT_SYMBOL(imx_dma_request_by_prio);
793
794static int __init imx_dma_init(void)
795{
796 int ret = 0;
797 int i;
798
e65fb009 799 dma_clk = clk_get(NULL, "dma");
58a85f46
SH		 800 clk_enable(dma_clk);
801
802 /* reset DMA module */
803 __raw_writel(DCR_DRST, DMA_BASE + DMA_DCR);
804
805#ifdef CONFIG_ARCH_MX1
806 ret = request_irq(DMA_INT, dma_irq_handler, 0, "DMA", NULL);
807 if (ret) {
808 printk(KERN_CRIT "Wow! Can't register IRQ for DMA\n");
809 return ret;
810 }
811
812 ret = request_irq(DMA_ERR, dma_err_handler, 0, "DMA", NULL);
813 if (ret) {
814 printk(KERN_CRIT "Wow! Can't register ERRIRQ for DMA\n");
815 free_irq(DMA_INT, NULL);
816 return ret;
817 }
818#endif
819 /* enable DMA module */
820 __raw_writel(DCR_DEN, DMA_BASE + DMA_DCR);
821
822 /* clear all interrupts */
823 __raw_writel((1 << IMX_DMA_CHANNELS) - 1, DMA_BASE + DMA_DISR);
824
825 /* disable interrupts */
826 __raw_writel((1 << IMX_DMA_CHANNELS) - 1, DMA_BASE + DMA_DIMR);
827
828 for (i = 0; i < IMX_DMA_CHANNELS; i++) {
829 imx_dma_channels[i].sg = NULL;
830 imx_dma_channels[i].dma_num = i;
831 }
832
833 return ret;
834}
835
836arch_initcall(imx_dma_init);
Linux kernel - Deliverables
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