MIPS: Yosemite, Emma: Fix off-by-two in arcs_cmdline buffer size check
[linux-2.6/linux-mips.git] / arch / frv / kernel / dma.c
blob156184e17e57d0b74483b6c47b30e8cde814a92a
1 /* dma.c: DMA controller management on FR401 and the like
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/sched.h>
14 #include <linux/spinlock.h>
15 #include <linux/errno.h>
16 #include <linux/init.h>
17 #include <asm/dma.h>
18 #include <asm/gpio-regs.h>
19 #include <asm/irc-regs.h>
20 #include <asm/cpu-irqs.h>
22 struct frv_dma_channel {
23 uint8_t flags;
24 #define FRV_DMA_FLAGS_RESERVED 0x01
25 #define FRV_DMA_FLAGS_INUSE 0x02
26 #define FRV_DMA_FLAGS_PAUSED 0x04
27 uint8_t cap; /* capabilities available */
28 int irq; /* completion IRQ */
29 uint32_t dreqbit;
30 uint32_t dackbit;
31 uint32_t donebit;
32 const unsigned long ioaddr; /* DMA controller regs addr */
33 const char *devname;
34 dma_irq_handler_t handler;
35 void *data;
39 #define __get_DMAC(IO,X) ({ *(volatile unsigned long *)((IO) + DMAC_##X##x); })
41 #define __set_DMAC(IO,X,V) \
42 do { \
43 *(volatile unsigned long *)((IO) + DMAC_##X##x) = (V); \
44 mb(); \
45 } while(0)
47 #define ___set_DMAC(IO,X,V) \
48 do { \
49 *(volatile unsigned long *)((IO) + DMAC_##X##x) = (V); \
50 } while(0)
53 static struct frv_dma_channel frv_dma_channels[FRV_DMA_NCHANS] = {
54 [0] = {
55 .cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK | FRV_DMA_CAP_DONE,
56 .irq = IRQ_CPU_DMA0,
57 .dreqbit = SIR_DREQ0_INPUT,
58 .dackbit = SOR_DACK0_OUTPUT,
59 .donebit = SOR_DONE0_OUTPUT,
60 .ioaddr = 0xfe000900,
62 [1] = {
63 .cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK | FRV_DMA_CAP_DONE,
64 .irq = IRQ_CPU_DMA1,
65 .dreqbit = SIR_DREQ1_INPUT,
66 .dackbit = SOR_DACK1_OUTPUT,
67 .donebit = SOR_DONE1_OUTPUT,
68 .ioaddr = 0xfe000980,
70 [2] = {
71 .cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK,
72 .irq = IRQ_CPU_DMA2,
73 .dreqbit = SIR_DREQ2_INPUT,
74 .dackbit = SOR_DACK2_OUTPUT,
75 .ioaddr = 0xfe000a00,
77 [3] = {
78 .cap = FRV_DMA_CAP_DREQ | FRV_DMA_CAP_DACK,
79 .irq = IRQ_CPU_DMA3,
80 .dreqbit = SIR_DREQ3_INPUT,
81 .dackbit = SOR_DACK3_OUTPUT,
82 .ioaddr = 0xfe000a80,
84 [4] = {
85 .cap = FRV_DMA_CAP_DREQ,
86 .irq = IRQ_CPU_DMA4,
87 .dreqbit = SIR_DREQ4_INPUT,
88 .ioaddr = 0xfe001000,
90 [5] = {
91 .cap = FRV_DMA_CAP_DREQ,
92 .irq = IRQ_CPU_DMA5,
93 .dreqbit = SIR_DREQ5_INPUT,
94 .ioaddr = 0xfe001080,
96 [6] = {
97 .cap = FRV_DMA_CAP_DREQ,
98 .irq = IRQ_CPU_DMA6,
99 .dreqbit = SIR_DREQ6_INPUT,
100 .ioaddr = 0xfe001100,
102 [7] = {
103 .cap = FRV_DMA_CAP_DREQ,
104 .irq = IRQ_CPU_DMA7,
105 .dreqbit = SIR_DREQ7_INPUT,
106 .ioaddr = 0xfe001180,
110 static DEFINE_RWLOCK(frv_dma_channels_lock);
112 unsigned long frv_dma_inprogress;
114 #define frv_clear_dma_inprogress(channel) \
115 atomic_clear_mask(1 << (channel), &frv_dma_inprogress);
117 #define frv_set_dma_inprogress(channel) \
118 atomic_set_mask(1 << (channel), &frv_dma_inprogress);
120 /*****************************************************************************/
122 * DMA irq handler - determine channel involved, grab status and call real handler
124 static irqreturn_t dma_irq_handler(int irq, void *_channel)
126 struct frv_dma_channel *channel = _channel;
128 frv_clear_dma_inprogress(channel - frv_dma_channels);
129 return channel->handler(channel - frv_dma_channels,
130 __get_DMAC(channel->ioaddr, CSTR),
131 channel->data);
133 } /* end dma_irq_handler() */
135 /*****************************************************************************/
137 * Determine which DMA controllers are present on this CPU
139 void __init frv_dma_init(void)
141 unsigned long psr = __get_PSR();
142 int num_dma, i;
144 /* First, determine how many DMA channels are available */
145 switch (PSR_IMPLE(psr)) {
146 case PSR_IMPLE_FR405:
147 case PSR_IMPLE_FR451:
148 case PSR_IMPLE_FR501:
149 case PSR_IMPLE_FR551:
150 num_dma = FRV_DMA_8CHANS;
151 break;
153 case PSR_IMPLE_FR401:
154 default:
155 num_dma = FRV_DMA_4CHANS;
156 break;
159 /* Now mark all of the non-existent channels as reserved */
160 for(i = num_dma; i < FRV_DMA_NCHANS; i++)
161 frv_dma_channels[i].flags = FRV_DMA_FLAGS_RESERVED;
163 } /* end frv_dma_init() */
165 /*****************************************************************************/
167 * allocate a DMA controller channel and the IRQ associated with it
169 int frv_dma_open(const char *devname,
170 unsigned long dmamask,
171 int dmacap,
172 dma_irq_handler_t handler,
173 unsigned long irq_flags,
174 void *data)
176 struct frv_dma_channel *channel;
177 int dma, ret;
178 uint32_t val;
180 write_lock(&frv_dma_channels_lock);
182 ret = -ENOSPC;
184 for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
185 channel = &frv_dma_channels[dma];
187 if (!test_bit(dma, &dmamask))
188 continue;
190 if ((channel->cap & dmacap) != dmacap)
191 continue;
193 if (!frv_dma_channels[dma].flags)
194 goto found;
197 goto out;
199 found:
200 ret = request_irq(channel->irq, dma_irq_handler, irq_flags, devname, channel);
201 if (ret < 0)
202 goto out;
204 /* okay, we've allocated all the resources */
205 channel = &frv_dma_channels[dma];
207 channel->flags |= FRV_DMA_FLAGS_INUSE;
208 channel->devname = devname;
209 channel->handler = handler;
210 channel->data = data;
212 /* Now make sure we are set up for DMA and not GPIO */
213 /* SIR bit must be set for DMA to work */
214 __set_SIR(channel->dreqbit | __get_SIR());
215 /* SOR bits depend on what the caller requests */
216 val = __get_SOR();
217 if(dmacap & FRV_DMA_CAP_DACK)
218 val |= channel->dackbit;
219 else
220 val &= ~channel->dackbit;
221 if(dmacap & FRV_DMA_CAP_DONE)
222 val |= channel->donebit;
223 else
224 val &= ~channel->donebit;
225 __set_SOR(val);
227 ret = dma;
228 out:
229 write_unlock(&frv_dma_channels_lock);
230 return ret;
231 } /* end frv_dma_open() */
233 EXPORT_SYMBOL(frv_dma_open);
235 /*****************************************************************************/
237 * close a DMA channel and its associated interrupt
239 void frv_dma_close(int dma)
241 struct frv_dma_channel *channel = &frv_dma_channels[dma];
242 unsigned long flags;
244 write_lock_irqsave(&frv_dma_channels_lock, flags);
246 free_irq(channel->irq, channel);
247 frv_dma_stop(dma);
249 channel->flags &= ~FRV_DMA_FLAGS_INUSE;
251 write_unlock_irqrestore(&frv_dma_channels_lock, flags);
252 } /* end frv_dma_close() */
254 EXPORT_SYMBOL(frv_dma_close);
256 /*****************************************************************************/
258 * set static configuration on a DMA channel
260 void frv_dma_config(int dma, unsigned long ccfr, unsigned long cctr, unsigned long apr)
262 unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
264 ___set_DMAC(ioaddr, CCFR, ccfr);
265 ___set_DMAC(ioaddr, CCTR, cctr);
266 ___set_DMAC(ioaddr, APR, apr);
267 mb();
269 } /* end frv_dma_config() */
271 EXPORT_SYMBOL(frv_dma_config);
273 /*****************************************************************************/
275 * start a DMA channel
277 void frv_dma_start(int dma,
278 unsigned long sba, unsigned long dba,
279 unsigned long pix, unsigned long six, unsigned long bcl)
281 unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
283 ___set_DMAC(ioaddr, SBA, sba);
284 ___set_DMAC(ioaddr, DBA, dba);
285 ___set_DMAC(ioaddr, PIX, pix);
286 ___set_DMAC(ioaddr, SIX, six);
287 ___set_DMAC(ioaddr, BCL, bcl);
288 ___set_DMAC(ioaddr, CSTR, 0);
289 mb();
291 __set_DMAC(ioaddr, CCTR, __get_DMAC(ioaddr, CCTR) | DMAC_CCTRx_ACT);
292 frv_set_dma_inprogress(dma);
294 } /* end frv_dma_start() */
296 EXPORT_SYMBOL(frv_dma_start);
298 /*****************************************************************************/
300 * restart a DMA channel that's been stopped in circular addressing mode by comparison-end
302 void frv_dma_restart_circular(int dma, unsigned long six)
304 unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
306 ___set_DMAC(ioaddr, SIX, six);
307 ___set_DMAC(ioaddr, CSTR, __get_DMAC(ioaddr, CSTR) & ~DMAC_CSTRx_CE);
308 mb();
310 __set_DMAC(ioaddr, CCTR, __get_DMAC(ioaddr, CCTR) | DMAC_CCTRx_ACT);
311 frv_set_dma_inprogress(dma);
313 } /* end frv_dma_restart_circular() */
315 EXPORT_SYMBOL(frv_dma_restart_circular);
317 /*****************************************************************************/
319 * stop a DMA channel
321 void frv_dma_stop(int dma)
323 unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
324 uint32_t cctr;
326 ___set_DMAC(ioaddr, CSTR, 0);
327 cctr = __get_DMAC(ioaddr, CCTR);
328 cctr &= ~(DMAC_CCTRx_IE | DMAC_CCTRx_ACT);
329 cctr |= DMAC_CCTRx_FC; /* fifo clear */
330 __set_DMAC(ioaddr, CCTR, cctr);
331 __set_DMAC(ioaddr, BCL, 0);
332 frv_clear_dma_inprogress(dma);
333 } /* end frv_dma_stop() */
335 EXPORT_SYMBOL(frv_dma_stop);
337 /*****************************************************************************/
339 * test interrupt status of DMA channel
341 int is_frv_dma_interrupting(int dma)
343 unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
345 return __get_DMAC(ioaddr, CSTR) & (1 << 23);
347 } /* end is_frv_dma_interrupting() */
349 EXPORT_SYMBOL(is_frv_dma_interrupting);
351 /*****************************************************************************/
353 * dump data about a DMA channel
355 void frv_dma_dump(int dma)
357 unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
358 unsigned long cstr, pix, six, bcl;
360 cstr = __get_DMAC(ioaddr, CSTR);
361 pix = __get_DMAC(ioaddr, PIX);
362 six = __get_DMAC(ioaddr, SIX);
363 bcl = __get_DMAC(ioaddr, BCL);
365 printk("DMA[%d] cstr=%lx pix=%lx six=%lx bcl=%lx\n", dma, cstr, pix, six, bcl);
367 } /* end frv_dma_dump() */
369 EXPORT_SYMBOL(frv_dma_dump);
371 /*****************************************************************************/
373 * pause all DMA controllers
374 * - called by clock mangling routines
375 * - caller must be holding interrupts disabled
377 void frv_dma_pause_all(void)
379 struct frv_dma_channel *channel;
380 unsigned long ioaddr;
381 unsigned long cstr, cctr;
382 int dma;
384 write_lock(&frv_dma_channels_lock);
386 for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
387 channel = &frv_dma_channels[dma];
389 if (!(channel->flags & FRV_DMA_FLAGS_INUSE))
390 continue;
392 ioaddr = channel->ioaddr;
393 cctr = __get_DMAC(ioaddr, CCTR);
394 if (cctr & DMAC_CCTRx_ACT) {
395 cctr &= ~DMAC_CCTRx_ACT;
396 __set_DMAC(ioaddr, CCTR, cctr);
398 do {
399 cstr = __get_DMAC(ioaddr, CSTR);
400 } while (cstr & DMAC_CSTRx_BUSY);
402 if (cstr & DMAC_CSTRx_FED)
403 channel->flags |= FRV_DMA_FLAGS_PAUSED;
404 frv_clear_dma_inprogress(dma);
408 } /* end frv_dma_pause_all() */
410 EXPORT_SYMBOL(frv_dma_pause_all);
412 /*****************************************************************************/
414 * resume paused DMA controllers
415 * - called by clock mangling routines
416 * - caller must be holding interrupts disabled
418 void frv_dma_resume_all(void)
420 struct frv_dma_channel *channel;
421 unsigned long ioaddr;
422 unsigned long cstr, cctr;
423 int dma;
425 for (dma = FRV_DMA_NCHANS - 1; dma >= 0; dma--) {
426 channel = &frv_dma_channels[dma];
428 if (!(channel->flags & FRV_DMA_FLAGS_PAUSED))
429 continue;
431 ioaddr = channel->ioaddr;
432 cstr = __get_DMAC(ioaddr, CSTR);
433 cstr &= ~(DMAC_CSTRx_FED | DMAC_CSTRx_INT);
434 __set_DMAC(ioaddr, CSTR, cstr);
436 cctr = __get_DMAC(ioaddr, CCTR);
437 cctr |= DMAC_CCTRx_ACT;
438 __set_DMAC(ioaddr, CCTR, cctr);
440 channel->flags &= ~FRV_DMA_FLAGS_PAUSED;
441 frv_set_dma_inprogress(dma);
444 write_unlock(&frv_dma_channels_lock);
446 } /* end frv_dma_resume_all() */
448 EXPORT_SYMBOL(frv_dma_resume_all);
450 /*****************************************************************************/
452 * dma status clear
454 void frv_dma_status_clear(int dma)
456 unsigned long ioaddr = frv_dma_channels[dma].ioaddr;
457 uint32_t cctr;
458 ___set_DMAC(ioaddr, CSTR, 0);
460 cctr = __get_DMAC(ioaddr, CCTR);
461 } /* end frv_dma_status_clear() */
463 EXPORT_SYMBOL(frv_dma_status_clear);