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1 | /* |
2 | * Driver for the Cirrus Logic EP93xx DMA Controller | |
3 | * | |
4 | * Copyright (C) 2011 Mika Westerberg | |
5 | * | |
6 | * DMA M2P implementation is based on the original | |
7 | * arch/arm/mach-ep93xx/dma-m2p.c which has following copyrights: | |
8 | * | |
9 | * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> | |
10 | * Copyright (C) 2006 Applied Data Systems | |
11 | * Copyright (C) 2009 Ryan Mallon <rmallon@gmail.com> | |
12 | * | |
13 | * This driver is based on dw_dmac and amba-pl08x drivers. | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or modify | |
16 | * it under the terms of the GNU General Public License as published by | |
17 | * the Free Software Foundation; either version 2 of the License, or | |
18 | * (at your option) any later version. | |
19 | */ | |
20 | ||
21 | #include <linux/clk.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/interrupt.h> | |
24 | #include <linux/dmaengine.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/slab.h> | |
27 | ||
28 | #include <mach/dma.h> | |
29 | ||
30 | /* M2P registers */ | |
31 | #define M2P_CONTROL 0x0000 | |
32 | #define M2P_CONTROL_STALLINT BIT(0) | |
33 | #define M2P_CONTROL_NFBINT BIT(1) | |
34 | #define M2P_CONTROL_CH_ERROR_INT BIT(3) | |
35 | #define M2P_CONTROL_ENABLE BIT(4) | |
36 | #define M2P_CONTROL_ICE BIT(6) | |
37 | ||
38 | #define M2P_INTERRUPT 0x0004 | |
39 | #define M2P_INTERRUPT_STALL BIT(0) | |
40 | #define M2P_INTERRUPT_NFB BIT(1) | |
41 | #define M2P_INTERRUPT_ERROR BIT(3) | |
42 | ||
43 | #define M2P_PPALLOC 0x0008 | |
44 | #define M2P_STATUS 0x000c | |
45 | ||
46 | #define M2P_MAXCNT0 0x0020 | |
47 | #define M2P_BASE0 0x0024 | |
48 | #define M2P_MAXCNT1 0x0030 | |
49 | #define M2P_BASE1 0x0034 | |
50 | ||
51 | #define M2P_STATE_IDLE 0 | |
52 | #define M2P_STATE_STALL 1 | |
53 | #define M2P_STATE_ON 2 | |
54 | #define M2P_STATE_NEXT 3 | |
55 | ||
56 | /* M2M registers */ | |
57 | #define M2M_CONTROL 0x0000 | |
58 | #define M2M_CONTROL_DONEINT BIT(2) | |
59 | #define M2M_CONTROL_ENABLE BIT(3) | |
60 | #define M2M_CONTROL_START BIT(4) | |
61 | #define M2M_CONTROL_DAH BIT(11) | |
62 | #define M2M_CONTROL_SAH BIT(12) | |
63 | #define M2M_CONTROL_PW_SHIFT 9 | |
64 | #define M2M_CONTROL_PW_8 (0 << M2M_CONTROL_PW_SHIFT) | |
65 | #define M2M_CONTROL_PW_16 (1 << M2M_CONTROL_PW_SHIFT) | |
66 | #define M2M_CONTROL_PW_32 (2 << M2M_CONTROL_PW_SHIFT) | |
67 | #define M2M_CONTROL_PW_MASK (3 << M2M_CONTROL_PW_SHIFT) | |
68 | #define M2M_CONTROL_TM_SHIFT 13 | |
69 | #define M2M_CONTROL_TM_TX (1 << M2M_CONTROL_TM_SHIFT) | |
70 | #define M2M_CONTROL_TM_RX (2 << M2M_CONTROL_TM_SHIFT) | |
71 | #define M2M_CONTROL_RSS_SHIFT 22 | |
72 | #define M2M_CONTROL_RSS_SSPRX (1 << M2M_CONTROL_RSS_SHIFT) | |
73 | #define M2M_CONTROL_RSS_SSPTX (2 << M2M_CONTROL_RSS_SHIFT) | |
74 | #define M2M_CONTROL_RSS_IDE (3 << M2M_CONTROL_RSS_SHIFT) | |
75 | #define M2M_CONTROL_NO_HDSK BIT(24) | |
76 | #define M2M_CONTROL_PWSC_SHIFT 25 | |
77 | ||
78 | #define M2M_INTERRUPT 0x0004 | |
79 | #define M2M_INTERRUPT_DONEINT BIT(1) | |
80 | ||
81 | #define M2M_BCR0 0x0010 | |
82 | #define M2M_BCR1 0x0014 | |
83 | #define M2M_SAR_BASE0 0x0018 | |
84 | #define M2M_SAR_BASE1 0x001c | |
85 | #define M2M_DAR_BASE0 0x002c | |
86 | #define M2M_DAR_BASE1 0x0030 | |
87 | ||
88 | #define DMA_MAX_CHAN_BYTES 0xffff | |
89 | #define DMA_MAX_CHAN_DESCRIPTORS 32 | |
90 | ||
91 | struct ep93xx_dma_engine; | |
92 | ||
93 | /** | |
94 | * struct ep93xx_dma_desc - EP93xx specific transaction descriptor | |
95 | * @src_addr: source address of the transaction | |
96 | * @dst_addr: destination address of the transaction | |
97 | * @size: size of the transaction (in bytes) | |
98 | * @complete: this descriptor is completed | |
99 | * @txd: dmaengine API descriptor | |
100 | * @tx_list: list of linked descriptors | |
101 | * @node: link used for putting this into a channel queue | |
102 | */ | |
103 | struct ep93xx_dma_desc { | |
104 | u32 src_addr; | |
105 | u32 dst_addr; | |
106 | size_t size; | |
107 | bool complete; | |
108 | struct dma_async_tx_descriptor txd; | |
109 | struct list_head tx_list; | |
110 | struct list_head node; | |
111 | }; | |
112 | ||
113 | /** | |
114 | * struct ep93xx_dma_chan - an EP93xx DMA M2P/M2M channel | |
115 | * @chan: dmaengine API channel | |
116 | * @edma: pointer to to the engine device | |
117 | * @regs: memory mapped registers | |
118 | * @irq: interrupt number of the channel | |
119 | * @clk: clock used by this channel | |
120 | * @tasklet: channel specific tasklet used for callbacks | |
121 | * @lock: lock protecting the fields following | |
122 | * @flags: flags for the channel | |
123 | * @buffer: which buffer to use next (0/1) | |
124 | * @last_completed: last completed cookie value | |
125 | * @active: flattened chain of descriptors currently being processed | |
126 | * @queue: pending descriptors which are handled next | |
127 | * @free_list: list of free descriptors which can be used | |
128 | * @runtime_addr: physical address currently used as dest/src (M2M only). This | |
129 | * is set via %DMA_SLAVE_CONFIG before slave operation is | |
130 | * prepared | |
131 | * @runtime_ctrl: M2M runtime values for the control register. | |
132 | * | |
133 | * As EP93xx DMA controller doesn't support real chained DMA descriptors we | |
134 | * will have slightly different scheme here: @active points to a head of | |
135 | * flattened DMA descriptor chain. | |
136 | * | |
137 | * @queue holds pending transactions. These are linked through the first | |
138 | * descriptor in the chain. When a descriptor is moved to the @active queue, | |
139 | * the first and chained descriptors are flattened into a single list. | |
140 | * | |
141 | * @chan.private holds pointer to &struct ep93xx_dma_data which contains | |
142 | * necessary channel configuration information. For memcpy channels this must | |
143 | * be %NULL. | |
144 | */ | |
145 | struct ep93xx_dma_chan { | |
146 | struct dma_chan chan; | |
147 | const struct ep93xx_dma_engine *edma; | |
148 | void __iomem *regs; | |
149 | int irq; | |
150 | struct clk *clk; | |
151 | struct tasklet_struct tasklet; | |
152 | /* protects the fields following */ | |
153 | spinlock_t lock; | |
154 | unsigned long flags; | |
155 | /* Channel is configured for cyclic transfers */ | |
156 | #define EP93XX_DMA_IS_CYCLIC 0 | |
157 | ||
158 | int buffer; | |
159 | dma_cookie_t last_completed; | |
160 | struct list_head active; | |
161 | struct list_head queue; | |
162 | struct list_head free_list; | |
163 | u32 runtime_addr; | |
164 | u32 runtime_ctrl; | |
165 | }; | |
166 | ||
167 | /** | |
168 | * struct ep93xx_dma_engine - the EP93xx DMA engine instance | |
169 | * @dma_dev: holds the dmaengine device | |
170 | * @m2m: is this an M2M or M2P device | |
171 | * @hw_setup: method which sets the channel up for operation | |
172 | * @hw_shutdown: shuts the channel down and flushes whatever is left | |
173 | * @hw_submit: pushes active descriptor(s) to the hardware | |
174 | * @hw_interrupt: handle the interrupt | |
175 | * @num_channels: number of channels for this instance | |
176 | * @channels: array of channels | |
177 | * | |
178 | * There is one instance of this struct for the M2P channels and one for the | |
179 | * M2M channels. hw_xxx() methods are used to perform operations which are | |
180 | * different on M2M and M2P channels. These methods are called with channel | |
181 | * lock held and interrupts disabled so they cannot sleep. | |
182 | */ | |
183 | struct ep93xx_dma_engine { | |
184 | struct dma_device dma_dev; | |
185 | bool m2m; | |
186 | int (*hw_setup)(struct ep93xx_dma_chan *); | |
187 | void (*hw_shutdown)(struct ep93xx_dma_chan *); | |
188 | void (*hw_submit)(struct ep93xx_dma_chan *); | |
189 | int (*hw_interrupt)(struct ep93xx_dma_chan *); | |
190 | #define INTERRUPT_UNKNOWN 0 | |
191 | #define INTERRUPT_DONE 1 | |
192 | #define INTERRUPT_NEXT_BUFFER 2 | |
193 | ||
194 | size_t num_channels; | |
195 | struct ep93xx_dma_chan channels[]; | |
196 | }; | |
197 | ||
198 | static inline struct device *chan2dev(struct ep93xx_dma_chan *edmac) | |
199 | { | |
200 | return &edmac->chan.dev->device; | |
201 | } | |
202 | ||
203 | static struct ep93xx_dma_chan *to_ep93xx_dma_chan(struct dma_chan *chan) | |
204 | { | |
205 | return container_of(chan, struct ep93xx_dma_chan, chan); | |
206 | } | |
207 | ||
208 | /** | |
209 | * ep93xx_dma_set_active - set new active descriptor chain | |
210 | * @edmac: channel | |
211 | * @desc: head of the new active descriptor chain | |
212 | * | |
213 | * Sets @desc to be the head of the new active descriptor chain. This is the | |
214 | * chain which is processed next. The active list must be empty before calling | |
215 | * this function. | |
216 | * | |
217 | * Called with @edmac->lock held and interrupts disabled. | |
218 | */ | |
219 | static void ep93xx_dma_set_active(struct ep93xx_dma_chan *edmac, | |
220 | struct ep93xx_dma_desc *desc) | |
221 | { | |
222 | BUG_ON(!list_empty(&edmac->active)); | |
223 | ||
224 | list_add_tail(&desc->node, &edmac->active); | |
225 | ||
226 | /* Flatten the @desc->tx_list chain into @edmac->active list */ | |
227 | while (!list_empty(&desc->tx_list)) { | |
228 | struct ep93xx_dma_desc *d = list_first_entry(&desc->tx_list, | |
229 | struct ep93xx_dma_desc, node); | |
230 | ||
231 | /* | |
232 | * We copy the callback parameters from the first descriptor | |
233 | * to all the chained descriptors. This way we can call the | |
234 | * callback without having to find out the first descriptor in | |
235 | * the chain. Useful for cyclic transfers. | |
236 | */ | |
237 | d->txd.callback = desc->txd.callback; | |
238 | d->txd.callback_param = desc->txd.callback_param; | |
239 | ||
240 | list_move_tail(&d->node, &edmac->active); | |
241 | } | |
242 | } | |
243 | ||
244 | /* Called with @edmac->lock held and interrupts disabled */ | |
245 | static struct ep93xx_dma_desc * | |
246 | ep93xx_dma_get_active(struct ep93xx_dma_chan *edmac) | |
247 | { | |
248 | return list_first_entry(&edmac->active, struct ep93xx_dma_desc, node); | |
249 | } | |
250 | ||
251 | /** | |
252 | * ep93xx_dma_advance_active - advances to the next active descriptor | |
253 | * @edmac: channel | |
254 | * | |
255 | * Function advances active descriptor to the next in the @edmac->active and | |
256 | * returns %true if we still have descriptors in the chain to process. | |
257 | * Otherwise returns %false. | |
258 | * | |
259 | * When the channel is in cyclic mode always returns %true. | |
260 | * | |
261 | * Called with @edmac->lock held and interrupts disabled. | |
262 | */ | |
263 | static bool ep93xx_dma_advance_active(struct ep93xx_dma_chan *edmac) | |
264 | { | |
265 | list_rotate_left(&edmac->active); | |
266 | ||
267 | if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags)) | |
268 | return true; | |
269 | ||
270 | /* | |
271 | * If txd.cookie is set it means that we are back in the first | |
272 | * descriptor in the chain and hence done with it. | |
273 | */ | |
274 | return !ep93xx_dma_get_active(edmac)->txd.cookie; | |
275 | } | |
276 | ||
277 | /* | |
278 | * M2P DMA implementation | |
279 | */ | |
280 | ||
281 | static void m2p_set_control(struct ep93xx_dma_chan *edmac, u32 control) | |
282 | { | |
283 | writel(control, edmac->regs + M2P_CONTROL); | |
284 | /* | |
285 | * EP93xx User's Guide states that we must perform a dummy read after | |
286 | * write to the control register. | |
287 | */ | |
288 | readl(edmac->regs + M2P_CONTROL); | |
289 | } | |
290 | ||
291 | static int m2p_hw_setup(struct ep93xx_dma_chan *edmac) | |
292 | { | |
293 | struct ep93xx_dma_data *data = edmac->chan.private; | |
294 | u32 control; | |
295 | ||
296 | writel(data->port & 0xf, edmac->regs + M2P_PPALLOC); | |
297 | ||
298 | control = M2P_CONTROL_CH_ERROR_INT | M2P_CONTROL_ICE | |
299 | | M2P_CONTROL_ENABLE; | |
300 | m2p_set_control(edmac, control); | |
301 | ||
302 | return 0; | |
303 | } | |
304 | ||
305 | static inline u32 m2p_channel_state(struct ep93xx_dma_chan *edmac) | |
306 | { | |
307 | return (readl(edmac->regs + M2P_STATUS) >> 4) & 0x3; | |
308 | } | |
309 | ||
310 | static void m2p_hw_shutdown(struct ep93xx_dma_chan *edmac) | |
311 | { | |
312 | u32 control; | |
313 | ||
314 | control = readl(edmac->regs + M2P_CONTROL); | |
315 | control &= ~(M2P_CONTROL_STALLINT | M2P_CONTROL_NFBINT); | |
316 | m2p_set_control(edmac, control); | |
317 | ||
318 | while (m2p_channel_state(edmac) >= M2P_STATE_ON) | |
319 | cpu_relax(); | |
320 | ||
321 | m2p_set_control(edmac, 0); | |
322 | ||
323 | while (m2p_channel_state(edmac) == M2P_STATE_STALL) | |
324 | cpu_relax(); | |
325 | } | |
326 | ||
327 | static void m2p_fill_desc(struct ep93xx_dma_chan *edmac) | |
328 | { | |
329 | struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac); | |
330 | u32 bus_addr; | |
331 | ||
332 | if (ep93xx_dma_chan_direction(&edmac->chan) == DMA_TO_DEVICE) | |
333 | bus_addr = desc->src_addr; | |
334 | else | |
335 | bus_addr = desc->dst_addr; | |
336 | ||
337 | if (edmac->buffer == 0) { | |
338 | writel(desc->size, edmac->regs + M2P_MAXCNT0); | |
339 | writel(bus_addr, edmac->regs + M2P_BASE0); | |
340 | } else { | |
341 | writel(desc->size, edmac->regs + M2P_MAXCNT1); | |
342 | writel(bus_addr, edmac->regs + M2P_BASE1); | |
343 | } | |
344 | ||
345 | edmac->buffer ^= 1; | |
346 | } | |
347 | ||
348 | static void m2p_hw_submit(struct ep93xx_dma_chan *edmac) | |
349 | { | |
350 | u32 control = readl(edmac->regs + M2P_CONTROL); | |
351 | ||
352 | m2p_fill_desc(edmac); | |
353 | control |= M2P_CONTROL_STALLINT; | |
354 | ||
355 | if (ep93xx_dma_advance_active(edmac)) { | |
356 | m2p_fill_desc(edmac); | |
357 | control |= M2P_CONTROL_NFBINT; | |
358 | } | |
359 | ||
360 | m2p_set_control(edmac, control); | |
361 | } | |
362 | ||
363 | static int m2p_hw_interrupt(struct ep93xx_dma_chan *edmac) | |
364 | { | |
365 | u32 irq_status = readl(edmac->regs + M2P_INTERRUPT); | |
366 | u32 control; | |
367 | ||
368 | if (irq_status & M2P_INTERRUPT_ERROR) { | |
369 | struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac); | |
370 | ||
371 | /* Clear the error interrupt */ | |
372 | writel(1, edmac->regs + M2P_INTERRUPT); | |
373 | ||
374 | /* | |
375 | * It seems that there is no easy way of reporting errors back | |
376 | * to client so we just report the error here and continue as | |
377 | * usual. | |
378 | * | |
379 | * Revisit this when there is a mechanism to report back the | |
380 | * errors. | |
381 | */ | |
382 | dev_err(chan2dev(edmac), | |
383 | "DMA transfer failed! Details:\n" | |
384 | "\tcookie : %d\n" | |
385 | "\tsrc_addr : 0x%08x\n" | |
386 | "\tdst_addr : 0x%08x\n" | |
387 | "\tsize : %zu\n", | |
388 | desc->txd.cookie, desc->src_addr, desc->dst_addr, | |
389 | desc->size); | |
390 | } | |
391 | ||
392 | switch (irq_status & (M2P_INTERRUPT_STALL | M2P_INTERRUPT_NFB)) { | |
393 | case M2P_INTERRUPT_STALL: | |
394 | /* Disable interrupts */ | |
395 | control = readl(edmac->regs + M2P_CONTROL); | |
396 | control &= ~(M2P_CONTROL_STALLINT | M2P_CONTROL_NFBINT); | |
397 | m2p_set_control(edmac, control); | |
398 | ||
399 | return INTERRUPT_DONE; | |
400 | ||
401 | case M2P_INTERRUPT_NFB: | |
402 | if (ep93xx_dma_advance_active(edmac)) | |
403 | m2p_fill_desc(edmac); | |
404 | ||
405 | return INTERRUPT_NEXT_BUFFER; | |
406 | } | |
407 | ||
408 | return INTERRUPT_UNKNOWN; | |
409 | } | |
410 | ||
411 | /* | |
412 | * M2M DMA implementation | |
413 | * | |
414 | * For the M2M transfers we don't use NFB at all. This is because it simply | |
415 | * doesn't work well with memcpy transfers. When you submit both buffers it is | |
416 | * extremely unlikely that you get an NFB interrupt, but it instead reports | |
417 | * DONE interrupt and both buffers are already transferred which means that we | |
418 | * weren't able to update the next buffer. | |
419 | * | |
420 | * So for now we "simulate" NFB by just submitting buffer after buffer | |
421 | * without double buffering. | |
422 | */ | |
423 | ||
424 | static int m2m_hw_setup(struct ep93xx_dma_chan *edmac) | |
425 | { | |
426 | const struct ep93xx_dma_data *data = edmac->chan.private; | |
427 | u32 control = 0; | |
428 | ||
429 | if (!data) { | |
430 | /* This is memcpy channel, nothing to configure */ | |
431 | writel(control, edmac->regs + M2M_CONTROL); | |
432 | return 0; | |
433 | } | |
434 | ||
435 | switch (data->port) { | |
436 | case EP93XX_DMA_SSP: | |
437 | /* | |
438 | * This was found via experimenting - anything less than 5 | |
439 | * causes the channel to perform only a partial transfer which | |
440 | * leads to problems since we don't get DONE interrupt then. | |
441 | */ | |
442 | control = (5 << M2M_CONTROL_PWSC_SHIFT); | |
443 | control |= M2M_CONTROL_NO_HDSK; | |
444 | ||
445 | if (data->direction == DMA_TO_DEVICE) { | |
446 | control |= M2M_CONTROL_DAH; | |
447 | control |= M2M_CONTROL_TM_TX; | |
448 | control |= M2M_CONTROL_RSS_SSPTX; | |
449 | } else { | |
450 | control |= M2M_CONTROL_SAH; | |
451 | control |= M2M_CONTROL_TM_RX; | |
452 | control |= M2M_CONTROL_RSS_SSPRX; | |
453 | } | |
454 | break; | |
455 | ||
456 | case EP93XX_DMA_IDE: | |
457 | /* | |
458 | * This IDE part is totally untested. Values below are taken | |
459 | * from the EP93xx Users's Guide and might not be correct. | |
460 | */ | |
461 | control |= M2M_CONTROL_NO_HDSK; | |
462 | control |= M2M_CONTROL_RSS_IDE; | |
463 | control |= M2M_CONTROL_PW_16; | |
464 | ||
465 | if (data->direction == DMA_TO_DEVICE) { | |
466 | /* Worst case from the UG */ | |
467 | control = (3 << M2M_CONTROL_PWSC_SHIFT); | |
468 | control |= M2M_CONTROL_DAH; | |
469 | control |= M2M_CONTROL_TM_TX; | |
470 | } else { | |
471 | control = (2 << M2M_CONTROL_PWSC_SHIFT); | |
472 | control |= M2M_CONTROL_SAH; | |
473 | control |= M2M_CONTROL_TM_RX; | |
474 | } | |
475 | break; | |
476 | ||
477 | default: | |
478 | return -EINVAL; | |
479 | } | |
480 | ||
481 | writel(control, edmac->regs + M2M_CONTROL); | |
482 | return 0; | |
483 | } | |
484 | ||
485 | static void m2m_hw_shutdown(struct ep93xx_dma_chan *edmac) | |
486 | { | |
487 | /* Just disable the channel */ | |
488 | writel(0, edmac->regs + M2M_CONTROL); | |
489 | } | |
490 | ||
491 | static void m2m_fill_desc(struct ep93xx_dma_chan *edmac) | |
492 | { | |
493 | struct ep93xx_dma_desc *desc = ep93xx_dma_get_active(edmac); | |
494 | ||
495 | if (edmac->buffer == 0) { | |
496 | writel(desc->src_addr, edmac->regs + M2M_SAR_BASE0); | |
497 | writel(desc->dst_addr, edmac->regs + M2M_DAR_BASE0); | |
498 | writel(desc->size, edmac->regs + M2M_BCR0); | |
499 | } else { | |
500 | writel(desc->src_addr, edmac->regs + M2M_SAR_BASE1); | |
501 | writel(desc->dst_addr, edmac->regs + M2M_DAR_BASE1); | |
502 | writel(desc->size, edmac->regs + M2M_BCR1); | |
503 | } | |
504 | ||
505 | edmac->buffer ^= 1; | |
506 | } | |
507 | ||
508 | static void m2m_hw_submit(struct ep93xx_dma_chan *edmac) | |
509 | { | |
510 | struct ep93xx_dma_data *data = edmac->chan.private; | |
511 | u32 control = readl(edmac->regs + M2M_CONTROL); | |
512 | ||
513 | /* | |
514 | * Since we allow clients to configure PW (peripheral width) we always | |
515 | * clear PW bits here and then set them according what is given in | |
516 | * the runtime configuration. | |
517 | */ | |
518 | control &= ~M2M_CONTROL_PW_MASK; | |
519 | control |= edmac->runtime_ctrl; | |
520 | ||
521 | m2m_fill_desc(edmac); | |
522 | control |= M2M_CONTROL_DONEINT; | |
523 | ||
524 | /* | |
525 | * Now we can finally enable the channel. For M2M channel this must be | |
526 | * done _after_ the BCRx registers are programmed. | |
527 | */ | |
528 | control |= M2M_CONTROL_ENABLE; | |
529 | writel(control, edmac->regs + M2M_CONTROL); | |
530 | ||
531 | if (!data) { | |
532 | /* | |
533 | * For memcpy channels the software trigger must be asserted | |
534 | * in order to start the memcpy operation. | |
535 | */ | |
536 | control |= M2M_CONTROL_START; | |
537 | writel(control, edmac->regs + M2M_CONTROL); | |
538 | } | |
539 | } | |
540 | ||
541 | static int m2m_hw_interrupt(struct ep93xx_dma_chan *edmac) | |
542 | { | |
543 | u32 control; | |
544 | ||
545 | if (!(readl(edmac->regs + M2M_INTERRUPT) & M2M_INTERRUPT_DONEINT)) | |
546 | return INTERRUPT_UNKNOWN; | |
547 | ||
548 | /* Clear the DONE bit */ | |
549 | writel(0, edmac->regs + M2M_INTERRUPT); | |
550 | ||
551 | /* Disable interrupts and the channel */ | |
552 | control = readl(edmac->regs + M2M_CONTROL); | |
553 | control &= ~(M2M_CONTROL_DONEINT | M2M_CONTROL_ENABLE); | |
554 | writel(control, edmac->regs + M2M_CONTROL); | |
555 | ||
556 | /* | |
557 | * Since we only get DONE interrupt we have to find out ourselves | |
558 | * whether there still is something to process. So we try to advance | |
559 | * the chain an see whether it succeeds. | |
560 | */ | |
561 | if (ep93xx_dma_advance_active(edmac)) { | |
562 | edmac->edma->hw_submit(edmac); | |
563 | return INTERRUPT_NEXT_BUFFER; | |
564 | } | |
565 | ||
566 | return INTERRUPT_DONE; | |
567 | } | |
568 | ||
569 | /* | |
570 | * DMA engine API implementation | |
571 | */ | |
572 | ||
573 | static struct ep93xx_dma_desc * | |
574 | ep93xx_dma_desc_get(struct ep93xx_dma_chan *edmac) | |
575 | { | |
576 | struct ep93xx_dma_desc *desc, *_desc; | |
577 | struct ep93xx_dma_desc *ret = NULL; | |
578 | unsigned long flags; | |
579 | ||
580 | spin_lock_irqsave(&edmac->lock, flags); | |
581 | list_for_each_entry_safe(desc, _desc, &edmac->free_list, node) { | |
582 | if (async_tx_test_ack(&desc->txd)) { | |
583 | list_del_init(&desc->node); | |
584 | ||
585 | /* Re-initialize the descriptor */ | |
586 | desc->src_addr = 0; | |
587 | desc->dst_addr = 0; | |
588 | desc->size = 0; | |
589 | desc->complete = false; | |
590 | desc->txd.cookie = 0; | |
591 | desc->txd.callback = NULL; | |
592 | desc->txd.callback_param = NULL; | |
593 | ||
594 | ret = desc; | |
595 | break; | |
596 | } | |
597 | } | |
598 | spin_unlock_irqrestore(&edmac->lock, flags); | |
599 | return ret; | |
600 | } | |
601 | ||
602 | static void ep93xx_dma_desc_put(struct ep93xx_dma_chan *edmac, | |
603 | struct ep93xx_dma_desc *desc) | |
604 | { | |
605 | if (desc) { | |
606 | unsigned long flags; | |
607 | ||
608 | spin_lock_irqsave(&edmac->lock, flags); | |
609 | list_splice_init(&desc->tx_list, &edmac->free_list); | |
610 | list_add(&desc->node, &edmac->free_list); | |
611 | spin_unlock_irqrestore(&edmac->lock, flags); | |
612 | } | |
613 | } | |
614 | ||
615 | /** | |
616 | * ep93xx_dma_advance_work - start processing the next pending transaction | |
617 | * @edmac: channel | |
618 | * | |
619 | * If we have pending transactions queued and we are currently idling, this | |
620 | * function takes the next queued transaction from the @edmac->queue and | |
621 | * pushes it to the hardware for execution. | |
622 | */ | |
623 | static void ep93xx_dma_advance_work(struct ep93xx_dma_chan *edmac) | |
624 | { | |
625 | struct ep93xx_dma_desc *new; | |
626 | unsigned long flags; | |
627 | ||
628 | spin_lock_irqsave(&edmac->lock, flags); | |
629 | if (!list_empty(&edmac->active) || list_empty(&edmac->queue)) { | |
630 | spin_unlock_irqrestore(&edmac->lock, flags); | |
631 | return; | |
632 | } | |
633 | ||
634 | /* Take the next descriptor from the pending queue */ | |
635 | new = list_first_entry(&edmac->queue, struct ep93xx_dma_desc, node); | |
636 | list_del_init(&new->node); | |
637 | ||
638 | ep93xx_dma_set_active(edmac, new); | |
639 | ||
640 | /* Push it to the hardware */ | |
641 | edmac->edma->hw_submit(edmac); | |
642 | spin_unlock_irqrestore(&edmac->lock, flags); | |
643 | } | |
644 | ||
645 | static void ep93xx_dma_unmap_buffers(struct ep93xx_dma_desc *desc) | |
646 | { | |
647 | struct device *dev = desc->txd.chan->device->dev; | |
648 | ||
649 | if (!(desc->txd.flags & DMA_COMPL_SKIP_SRC_UNMAP)) { | |
650 | if (desc->txd.flags & DMA_COMPL_SRC_UNMAP_SINGLE) | |
651 | dma_unmap_single(dev, desc->src_addr, desc->size, | |
652 | DMA_TO_DEVICE); | |
653 | else | |
654 | dma_unmap_page(dev, desc->src_addr, desc->size, | |
655 | DMA_TO_DEVICE); | |
656 | } | |
657 | if (!(desc->txd.flags & DMA_COMPL_SKIP_DEST_UNMAP)) { | |
658 | if (desc->txd.flags & DMA_COMPL_DEST_UNMAP_SINGLE) | |
659 | dma_unmap_single(dev, desc->dst_addr, desc->size, | |
660 | DMA_FROM_DEVICE); | |
661 | else | |
662 | dma_unmap_page(dev, desc->dst_addr, desc->size, | |
663 | DMA_FROM_DEVICE); | |
664 | } | |
665 | } | |
666 | ||
667 | static void ep93xx_dma_tasklet(unsigned long data) | |
668 | { | |
669 | struct ep93xx_dma_chan *edmac = (struct ep93xx_dma_chan *)data; | |
670 | struct ep93xx_dma_desc *desc, *d; | |
671 | dma_async_tx_callback callback; | |
672 | void *callback_param; | |
673 | LIST_HEAD(list); | |
674 | ||
675 | spin_lock_irq(&edmac->lock); | |
676 | desc = ep93xx_dma_get_active(edmac); | |
677 | if (desc->complete) { | |
678 | edmac->last_completed = desc->txd.cookie; | |
679 | list_splice_init(&edmac->active, &list); | |
680 | } | |
681 | spin_unlock_irq(&edmac->lock); | |
682 | ||
683 | /* Pick up the next descriptor from the queue */ | |
684 | ep93xx_dma_advance_work(edmac); | |
685 | ||
686 | callback = desc->txd.callback; | |
687 | callback_param = desc->txd.callback_param; | |
688 | ||
689 | /* Now we can release all the chained descriptors */ | |
690 | list_for_each_entry_safe(desc, d, &list, node) { | |
691 | /* | |
692 | * For the memcpy channels the API requires us to unmap the | |
693 | * buffers unless requested otherwise. | |
694 | */ | |
695 | if (!edmac->chan.private) | |
696 | ep93xx_dma_unmap_buffers(desc); | |
697 | ||
698 | ep93xx_dma_desc_put(edmac, desc); | |
699 | } | |
700 | ||
701 | if (callback) | |
702 | callback(callback_param); | |
703 | } | |
704 | ||
705 | static irqreturn_t ep93xx_dma_interrupt(int irq, void *dev_id) | |
706 | { | |
707 | struct ep93xx_dma_chan *edmac = dev_id; | |
708 | irqreturn_t ret = IRQ_HANDLED; | |
709 | ||
710 | spin_lock(&edmac->lock); | |
711 | ||
712 | switch (edmac->edma->hw_interrupt(edmac)) { | |
713 | case INTERRUPT_DONE: | |
714 | ep93xx_dma_get_active(edmac)->complete = true; | |
715 | tasklet_schedule(&edmac->tasklet); | |
716 | break; | |
717 | ||
718 | case INTERRUPT_NEXT_BUFFER: | |
719 | if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags)) | |
720 | tasklet_schedule(&edmac->tasklet); | |
721 | break; | |
722 | ||
723 | default: | |
724 | dev_warn(chan2dev(edmac), "unknown interrupt!\n"); | |
725 | ret = IRQ_NONE; | |
726 | break; | |
727 | } | |
728 | ||
729 | spin_unlock(&edmac->lock); | |
730 | return ret; | |
731 | } | |
732 | ||
733 | /** | |
734 | * ep93xx_dma_tx_submit - set the prepared descriptor(s) to be executed | |
735 | * @tx: descriptor to be executed | |
736 | * | |
737 | * Function will execute given descriptor on the hardware or if the hardware | |
738 | * is busy, queue the descriptor to be executed later on. Returns cookie which | |
739 | * can be used to poll the status of the descriptor. | |
740 | */ | |
741 | static dma_cookie_t ep93xx_dma_tx_submit(struct dma_async_tx_descriptor *tx) | |
742 | { | |
743 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(tx->chan); | |
744 | struct ep93xx_dma_desc *desc; | |
745 | dma_cookie_t cookie; | |
746 | unsigned long flags; | |
747 | ||
748 | spin_lock_irqsave(&edmac->lock, flags); | |
749 | ||
750 | cookie = edmac->chan.cookie; | |
751 | ||
752 | if (++cookie < 0) | |
753 | cookie = 1; | |
754 | ||
755 | desc = container_of(tx, struct ep93xx_dma_desc, txd); | |
756 | ||
757 | edmac->chan.cookie = cookie; | |
758 | desc->txd.cookie = cookie; | |
759 | ||
760 | /* | |
761 | * If nothing is currently prosessed, we push this descriptor | |
762 | * directly to the hardware. Otherwise we put the descriptor | |
763 | * to the pending queue. | |
764 | */ | |
765 | if (list_empty(&edmac->active)) { | |
766 | ep93xx_dma_set_active(edmac, desc); | |
767 | edmac->edma->hw_submit(edmac); | |
768 | } else { | |
769 | list_add_tail(&desc->node, &edmac->queue); | |
770 | } | |
771 | ||
772 | spin_unlock_irqrestore(&edmac->lock, flags); | |
773 | return cookie; | |
774 | } | |
775 | ||
776 | /** | |
777 | * ep93xx_dma_alloc_chan_resources - allocate resources for the channel | |
778 | * @chan: channel to allocate resources | |
779 | * | |
780 | * Function allocates necessary resources for the given DMA channel and | |
781 | * returns number of allocated descriptors for the channel. Negative errno | |
782 | * is returned in case of failure. | |
783 | */ | |
784 | static int ep93xx_dma_alloc_chan_resources(struct dma_chan *chan) | |
785 | { | |
786 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); | |
787 | struct ep93xx_dma_data *data = chan->private; | |
788 | const char *name = dma_chan_name(chan); | |
789 | int ret, i; | |
790 | ||
791 | /* Sanity check the channel parameters */ | |
792 | if (!edmac->edma->m2m) { | |
793 | if (!data) | |
794 | return -EINVAL; | |
795 | if (data->port < EP93XX_DMA_I2S1 || | |
796 | data->port > EP93XX_DMA_IRDA) | |
797 | return -EINVAL; | |
798 | if (data->direction != ep93xx_dma_chan_direction(chan)) | |
799 | return -EINVAL; | |
800 | } else { | |
801 | if (data) { | |
802 | switch (data->port) { | |
803 | case EP93XX_DMA_SSP: | |
804 | case EP93XX_DMA_IDE: | |
805 | if (data->direction != DMA_TO_DEVICE && | |
806 | data->direction != DMA_FROM_DEVICE) | |
807 | return -EINVAL; | |
808 | break; | |
809 | default: | |
810 | return -EINVAL; | |
811 | } | |
812 | } | |
813 | } | |
814 | ||
815 | if (data && data->name) | |
816 | name = data->name; | |
817 | ||
818 | ret = clk_enable(edmac->clk); | |
819 | if (ret) | |
820 | return ret; | |
821 | ||
822 | ret = request_irq(edmac->irq, ep93xx_dma_interrupt, 0, name, edmac); | |
823 | if (ret) | |
824 | goto fail_clk_disable; | |
825 | ||
826 | spin_lock_irq(&edmac->lock); | |
827 | edmac->last_completed = 1; | |
828 | edmac->chan.cookie = 1; | |
829 | ret = edmac->edma->hw_setup(edmac); | |
830 | spin_unlock_irq(&edmac->lock); | |
831 | ||
832 | if (ret) | |
833 | goto fail_free_irq; | |
834 | ||
835 | for (i = 0; i < DMA_MAX_CHAN_DESCRIPTORS; i++) { | |
836 | struct ep93xx_dma_desc *desc; | |
837 | ||
838 | desc = kzalloc(sizeof(*desc), GFP_KERNEL); | |
839 | if (!desc) { | |
840 | dev_warn(chan2dev(edmac), "not enough descriptors\n"); | |
841 | break; | |
842 | } | |
843 | ||
844 | INIT_LIST_HEAD(&desc->tx_list); | |
845 | ||
846 | dma_async_tx_descriptor_init(&desc->txd, chan); | |
847 | desc->txd.flags = DMA_CTRL_ACK; | |
848 | desc->txd.tx_submit = ep93xx_dma_tx_submit; | |
849 | ||
850 | ep93xx_dma_desc_put(edmac, desc); | |
851 | } | |
852 | ||
853 | return i; | |
854 | ||
855 | fail_free_irq: | |
856 | free_irq(edmac->irq, edmac); | |
857 | fail_clk_disable: | |
858 | clk_disable(edmac->clk); | |
859 | ||
860 | return ret; | |
861 | } | |
862 | ||
863 | /** | |
864 | * ep93xx_dma_free_chan_resources - release resources for the channel | |
865 | * @chan: channel | |
866 | * | |
867 | * Function releases all the resources allocated for the given channel. | |
868 | * The channel must be idle when this is called. | |
869 | */ | |
870 | static void ep93xx_dma_free_chan_resources(struct dma_chan *chan) | |
871 | { | |
872 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); | |
873 | struct ep93xx_dma_desc *desc, *d; | |
874 | unsigned long flags; | |
875 | LIST_HEAD(list); | |
876 | ||
877 | BUG_ON(!list_empty(&edmac->active)); | |
878 | BUG_ON(!list_empty(&edmac->queue)); | |
879 | ||
880 | spin_lock_irqsave(&edmac->lock, flags); | |
881 | edmac->edma->hw_shutdown(edmac); | |
882 | edmac->runtime_addr = 0; | |
883 | edmac->runtime_ctrl = 0; | |
884 | edmac->buffer = 0; | |
885 | list_splice_init(&edmac->free_list, &list); | |
886 | spin_unlock_irqrestore(&edmac->lock, flags); | |
887 | ||
888 | list_for_each_entry_safe(desc, d, &list, node) | |
889 | kfree(desc); | |
890 | ||
891 | clk_disable(edmac->clk); | |
892 | free_irq(edmac->irq, edmac); | |
893 | } | |
894 | ||
895 | /** | |
896 | * ep93xx_dma_prep_dma_memcpy - prepare a memcpy DMA operation | |
897 | * @chan: channel | |
898 | * @dest: destination bus address | |
899 | * @src: source bus address | |
900 | * @len: size of the transaction | |
901 | * @flags: flags for the descriptor | |
902 | * | |
903 | * Returns a valid DMA descriptor or %NULL in case of failure. | |
904 | */ | |
905 | struct dma_async_tx_descriptor * | |
906 | ep93xx_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, | |
907 | dma_addr_t src, size_t len, unsigned long flags) | |
908 | { | |
909 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); | |
910 | struct ep93xx_dma_desc *desc, *first; | |
911 | size_t bytes, offset; | |
912 | ||
913 | first = NULL; | |
914 | for (offset = 0; offset < len; offset += bytes) { | |
915 | desc = ep93xx_dma_desc_get(edmac); | |
916 | if (!desc) { | |
917 | dev_warn(chan2dev(edmac), "couln't get descriptor\n"); | |
918 | goto fail; | |
919 | } | |
920 | ||
921 | bytes = min_t(size_t, len - offset, DMA_MAX_CHAN_BYTES); | |
922 | ||
923 | desc->src_addr = src + offset; | |
924 | desc->dst_addr = dest + offset; | |
925 | desc->size = bytes; | |
926 | ||
927 | if (!first) | |
928 | first = desc; | |
929 | else | |
930 | list_add_tail(&desc->node, &first->tx_list); | |
931 | } | |
932 | ||
933 | first->txd.cookie = -EBUSY; | |
934 | first->txd.flags = flags; | |
935 | ||
936 | return &first->txd; | |
937 | fail: | |
938 | ep93xx_dma_desc_put(edmac, first); | |
939 | return NULL; | |
940 | } | |
941 | ||
942 | /** | |
943 | * ep93xx_dma_prep_slave_sg - prepare a slave DMA operation | |
944 | * @chan: channel | |
945 | * @sgl: list of buffers to transfer | |
946 | * @sg_len: number of entries in @sgl | |
947 | * @dir: direction of tha DMA transfer | |
948 | * @flags: flags for the descriptor | |
949 | * | |
950 | * Returns a valid DMA descriptor or %NULL in case of failure. | |
951 | */ | |
952 | static struct dma_async_tx_descriptor * | |
953 | ep93xx_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, | |
954 | unsigned int sg_len, enum dma_data_direction dir, | |
955 | unsigned long flags) | |
956 | { | |
957 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); | |
958 | struct ep93xx_dma_desc *desc, *first; | |
959 | struct scatterlist *sg; | |
960 | int i; | |
961 | ||
962 | if (!edmac->edma->m2m && dir != ep93xx_dma_chan_direction(chan)) { | |
963 | dev_warn(chan2dev(edmac), | |
964 | "channel was configured with different direction\n"); | |
965 | return NULL; | |
966 | } | |
967 | ||
968 | if (test_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags)) { | |
969 | dev_warn(chan2dev(edmac), | |
970 | "channel is already used for cyclic transfers\n"); | |
971 | return NULL; | |
972 | } | |
973 | ||
974 | first = NULL; | |
975 | for_each_sg(sgl, sg, sg_len, i) { | |
976 | size_t sg_len = sg_dma_len(sg); | |
977 | ||
978 | if (sg_len > DMA_MAX_CHAN_BYTES) { | |
979 | dev_warn(chan2dev(edmac), "too big transfer size %d\n", | |
980 | sg_len); | |
981 | goto fail; | |
982 | } | |
983 | ||
984 | desc = ep93xx_dma_desc_get(edmac); | |
985 | if (!desc) { | |
986 | dev_warn(chan2dev(edmac), "couln't get descriptor\n"); | |
987 | goto fail; | |
988 | } | |
989 | ||
990 | if (dir == DMA_TO_DEVICE) { | |
991 | desc->src_addr = sg_dma_address(sg); | |
992 | desc->dst_addr = edmac->runtime_addr; | |
993 | } else { | |
994 | desc->src_addr = edmac->runtime_addr; | |
995 | desc->dst_addr = sg_dma_address(sg); | |
996 | } | |
997 | desc->size = sg_len; | |
998 | ||
999 | if (!first) | |
1000 | first = desc; | |
1001 | else | |
1002 | list_add_tail(&desc->node, &first->tx_list); | |
1003 | } | |
1004 | ||
1005 | first->txd.cookie = -EBUSY; | |
1006 | first->txd.flags = flags; | |
1007 | ||
1008 | return &first->txd; | |
1009 | ||
1010 | fail: | |
1011 | ep93xx_dma_desc_put(edmac, first); | |
1012 | return NULL; | |
1013 | } | |
1014 | ||
1015 | /** | |
1016 | * ep93xx_dma_prep_dma_cyclic - prepare a cyclic DMA operation | |
1017 | * @chan: channel | |
1018 | * @dma_addr: DMA mapped address of the buffer | |
1019 | * @buf_len: length of the buffer (in bytes) | |
1020 | * @period_len: lenght of a single period | |
1021 | * @dir: direction of the operation | |
1022 | * | |
1023 | * Prepares a descriptor for cyclic DMA operation. This means that once the | |
1024 | * descriptor is submitted, we will be submitting in a @period_len sized | |
1025 | * buffers and calling callback once the period has been elapsed. Transfer | |
1026 | * terminates only when client calls dmaengine_terminate_all() for this | |
1027 | * channel. | |
1028 | * | |
1029 | * Returns a valid DMA descriptor or %NULL in case of failure. | |
1030 | */ | |
1031 | static struct dma_async_tx_descriptor * | |
1032 | ep93xx_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr, | |
1033 | size_t buf_len, size_t period_len, | |
1034 | enum dma_data_direction dir) | |
1035 | { | |
1036 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); | |
1037 | struct ep93xx_dma_desc *desc, *first; | |
1038 | size_t offset = 0; | |
1039 | ||
1040 | if (!edmac->edma->m2m && dir != ep93xx_dma_chan_direction(chan)) { | |
1041 | dev_warn(chan2dev(edmac), | |
1042 | "channel was configured with different direction\n"); | |
1043 | return NULL; | |
1044 | } | |
1045 | ||
1046 | if (test_and_set_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags)) { | |
1047 | dev_warn(chan2dev(edmac), | |
1048 | "channel is already used for cyclic transfers\n"); | |
1049 | return NULL; | |
1050 | } | |
1051 | ||
1052 | if (period_len > DMA_MAX_CHAN_BYTES) { | |
1053 | dev_warn(chan2dev(edmac), "too big period length %d\n", | |
1054 | period_len); | |
1055 | return NULL; | |
1056 | } | |
1057 | ||
1058 | /* Split the buffer into period size chunks */ | |
1059 | first = NULL; | |
1060 | for (offset = 0; offset < buf_len; offset += period_len) { | |
1061 | desc = ep93xx_dma_desc_get(edmac); | |
1062 | if (!desc) { | |
1063 | dev_warn(chan2dev(edmac), "couln't get descriptor\n"); | |
1064 | goto fail; | |
1065 | } | |
1066 | ||
1067 | if (dir == DMA_TO_DEVICE) { | |
1068 | desc->src_addr = dma_addr + offset; | |
1069 | desc->dst_addr = edmac->runtime_addr; | |
1070 | } else { | |
1071 | desc->src_addr = edmac->runtime_addr; | |
1072 | desc->dst_addr = dma_addr + offset; | |
1073 | } | |
1074 | ||
1075 | desc->size = period_len; | |
1076 | ||
1077 | if (!first) | |
1078 | first = desc; | |
1079 | else | |
1080 | list_add_tail(&desc->node, &first->tx_list); | |
1081 | } | |
1082 | ||
1083 | first->txd.cookie = -EBUSY; | |
1084 | ||
1085 | return &first->txd; | |
1086 | ||
1087 | fail: | |
1088 | ep93xx_dma_desc_put(edmac, first); | |
1089 | return NULL; | |
1090 | } | |
1091 | ||
1092 | /** | |
1093 | * ep93xx_dma_terminate_all - terminate all transactions | |
1094 | * @edmac: channel | |
1095 | * | |
1096 | * Stops all DMA transactions. All descriptors are put back to the | |
1097 | * @edmac->free_list and callbacks are _not_ called. | |
1098 | */ | |
1099 | static int ep93xx_dma_terminate_all(struct ep93xx_dma_chan *edmac) | |
1100 | { | |
1101 | struct ep93xx_dma_desc *desc, *_d; | |
1102 | unsigned long flags; | |
1103 | LIST_HEAD(list); | |
1104 | ||
1105 | spin_lock_irqsave(&edmac->lock, flags); | |
1106 | /* First we disable and flush the DMA channel */ | |
1107 | edmac->edma->hw_shutdown(edmac); | |
1108 | clear_bit(EP93XX_DMA_IS_CYCLIC, &edmac->flags); | |
1109 | list_splice_init(&edmac->active, &list); | |
1110 | list_splice_init(&edmac->queue, &list); | |
1111 | /* | |
1112 | * We then re-enable the channel. This way we can continue submitting | |
1113 | * the descriptors by just calling ->hw_submit() again. | |
1114 | */ | |
1115 | edmac->edma->hw_setup(edmac); | |
1116 | spin_unlock_irqrestore(&edmac->lock, flags); | |
1117 | ||
1118 | list_for_each_entry_safe(desc, _d, &list, node) | |
1119 | ep93xx_dma_desc_put(edmac, desc); | |
1120 | ||
1121 | return 0; | |
1122 | } | |
1123 | ||
1124 | static int ep93xx_dma_slave_config(struct ep93xx_dma_chan *edmac, | |
1125 | struct dma_slave_config *config) | |
1126 | { | |
1127 | enum dma_slave_buswidth width; | |
1128 | unsigned long flags; | |
1129 | u32 addr, ctrl; | |
1130 | ||
1131 | if (!edmac->edma->m2m) | |
1132 | return -EINVAL; | |
1133 | ||
1134 | switch (config->direction) { | |
1135 | case DMA_FROM_DEVICE: | |
1136 | width = config->src_addr_width; | |
1137 | addr = config->src_addr; | |
1138 | break; | |
1139 | ||
1140 | case DMA_TO_DEVICE: | |
1141 | width = config->dst_addr_width; | |
1142 | addr = config->dst_addr; | |
1143 | break; | |
1144 | ||
1145 | default: | |
1146 | return -EINVAL; | |
1147 | } | |
1148 | ||
1149 | switch (width) { | |
1150 | case DMA_SLAVE_BUSWIDTH_1_BYTE: | |
1151 | ctrl = 0; | |
1152 | break; | |
1153 | case DMA_SLAVE_BUSWIDTH_2_BYTES: | |
1154 | ctrl = M2M_CONTROL_PW_16; | |
1155 | break; | |
1156 | case DMA_SLAVE_BUSWIDTH_4_BYTES: | |
1157 | ctrl = M2M_CONTROL_PW_32; | |
1158 | break; | |
1159 | default: | |
1160 | return -EINVAL; | |
1161 | } | |
1162 | ||
1163 | spin_lock_irqsave(&edmac->lock, flags); | |
1164 | edmac->runtime_addr = addr; | |
1165 | edmac->runtime_ctrl = ctrl; | |
1166 | spin_unlock_irqrestore(&edmac->lock, flags); | |
1167 | ||
1168 | return 0; | |
1169 | } | |
1170 | ||
1171 | /** | |
1172 | * ep93xx_dma_control - manipulate all pending operations on a channel | |
1173 | * @chan: channel | |
1174 | * @cmd: control command to perform | |
1175 | * @arg: optional argument | |
1176 | * | |
1177 | * Controls the channel. Function returns %0 in case of success or negative | |
1178 | * error in case of failure. | |
1179 | */ | |
1180 | static int ep93xx_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, | |
1181 | unsigned long arg) | |
1182 | { | |
1183 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); | |
1184 | struct dma_slave_config *config; | |
1185 | ||
1186 | switch (cmd) { | |
1187 | case DMA_TERMINATE_ALL: | |
1188 | return ep93xx_dma_terminate_all(edmac); | |
1189 | ||
1190 | case DMA_SLAVE_CONFIG: | |
1191 | config = (struct dma_slave_config *)arg; | |
1192 | return ep93xx_dma_slave_config(edmac, config); | |
1193 | ||
1194 | default: | |
1195 | break; | |
1196 | } | |
1197 | ||
1198 | return -ENOSYS; | |
1199 | } | |
1200 | ||
1201 | /** | |
1202 | * ep93xx_dma_tx_status - check if a transaction is completed | |
1203 | * @chan: channel | |
1204 | * @cookie: transaction specific cookie | |
1205 | * @state: state of the transaction is stored here if given | |
1206 | * | |
1207 | * This function can be used to query state of a given transaction. | |
1208 | */ | |
1209 | static enum dma_status ep93xx_dma_tx_status(struct dma_chan *chan, | |
1210 | dma_cookie_t cookie, | |
1211 | struct dma_tx_state *state) | |
1212 | { | |
1213 | struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan); | |
1214 | dma_cookie_t last_used, last_completed; | |
1215 | enum dma_status ret; | |
1216 | unsigned long flags; | |
1217 | ||
1218 | spin_lock_irqsave(&edmac->lock, flags); | |
1219 | last_used = chan->cookie; | |
1220 | last_completed = edmac->last_completed; | |
1221 | spin_unlock_irqrestore(&edmac->lock, flags); | |
1222 | ||
1223 | ret = dma_async_is_complete(cookie, last_completed, last_used); | |
1224 | dma_set_tx_state(state, last_completed, last_used, 0); | |
1225 | ||
1226 | return ret; | |
1227 | } | |
1228 | ||
1229 | /** | |
1230 | * ep93xx_dma_issue_pending - push pending transactions to the hardware | |
1231 | * @chan: channel | |
1232 | * | |
1233 | * When this function is called, all pending transactions are pushed to the | |
1234 | * hardware and executed. | |
1235 | */ | |
1236 | static void ep93xx_dma_issue_pending(struct dma_chan *chan) | |
1237 | { | |
1238 | ep93xx_dma_advance_work(to_ep93xx_dma_chan(chan)); | |
1239 | } | |
1240 | ||
1241 | static int __init ep93xx_dma_probe(struct platform_device *pdev) | |
1242 | { | |
1243 | struct ep93xx_dma_platform_data *pdata = dev_get_platdata(&pdev->dev); | |
1244 | struct ep93xx_dma_engine *edma; | |
1245 | struct dma_device *dma_dev; | |
1246 | size_t edma_size; | |
1247 | int ret, i; | |
1248 | ||
1249 | edma_size = pdata->num_channels * sizeof(struct ep93xx_dma_chan); | |
1250 | edma = kzalloc(sizeof(*edma) + edma_size, GFP_KERNEL); | |
1251 | if (!edma) | |
1252 | return -ENOMEM; | |
1253 | ||
1254 | dma_dev = &edma->dma_dev; | |
1255 | edma->m2m = platform_get_device_id(pdev)->driver_data; | |
1256 | edma->num_channels = pdata->num_channels; | |
1257 | ||
1258 | INIT_LIST_HEAD(&dma_dev->channels); | |
1259 | for (i = 0; i < pdata->num_channels; i++) { | |
1260 | const struct ep93xx_dma_chan_data *cdata = &pdata->channels[i]; | |
1261 | struct ep93xx_dma_chan *edmac = &edma->channels[i]; | |
1262 | ||
1263 | edmac->chan.device = dma_dev; | |
1264 | edmac->regs = cdata->base; | |
1265 | edmac->irq = cdata->irq; | |
1266 | edmac->edma = edma; | |
1267 | ||
1268 | edmac->clk = clk_get(NULL, cdata->name); | |
1269 | if (IS_ERR(edmac->clk)) { | |
1270 | dev_warn(&pdev->dev, "failed to get clock for %s\n", | |
1271 | cdata->name); | |
1272 | continue; | |
1273 | } | |
1274 | ||
1275 | spin_lock_init(&edmac->lock); | |
1276 | INIT_LIST_HEAD(&edmac->active); | |
1277 | INIT_LIST_HEAD(&edmac->queue); | |
1278 | INIT_LIST_HEAD(&edmac->free_list); | |
1279 | tasklet_init(&edmac->tasklet, ep93xx_dma_tasklet, | |
1280 | (unsigned long)edmac); | |
1281 | ||
1282 | list_add_tail(&edmac->chan.device_node, | |
1283 | &dma_dev->channels); | |
1284 | } | |
1285 | ||
1286 | dma_cap_zero(dma_dev->cap_mask); | |
1287 | dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); | |
1288 | dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask); | |
1289 | ||
1290 | dma_dev->dev = &pdev->dev; | |
1291 | dma_dev->device_alloc_chan_resources = ep93xx_dma_alloc_chan_resources; | |
1292 | dma_dev->device_free_chan_resources = ep93xx_dma_free_chan_resources; | |
1293 | dma_dev->device_prep_slave_sg = ep93xx_dma_prep_slave_sg; | |
1294 | dma_dev->device_prep_dma_cyclic = ep93xx_dma_prep_dma_cyclic; | |
1295 | dma_dev->device_control = ep93xx_dma_control; | |
1296 | dma_dev->device_issue_pending = ep93xx_dma_issue_pending; | |
1297 | dma_dev->device_tx_status = ep93xx_dma_tx_status; | |
1298 | ||
1299 | dma_set_max_seg_size(dma_dev->dev, DMA_MAX_CHAN_BYTES); | |
1300 | ||
1301 | if (edma->m2m) { | |
1302 | dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); | |
1303 | dma_dev->device_prep_dma_memcpy = ep93xx_dma_prep_dma_memcpy; | |
1304 | ||
1305 | edma->hw_setup = m2m_hw_setup; | |
1306 | edma->hw_shutdown = m2m_hw_shutdown; | |
1307 | edma->hw_submit = m2m_hw_submit; | |
1308 | edma->hw_interrupt = m2m_hw_interrupt; | |
1309 | } else { | |
1310 | dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask); | |
1311 | ||
1312 | edma->hw_setup = m2p_hw_setup; | |
1313 | edma->hw_shutdown = m2p_hw_shutdown; | |
1314 | edma->hw_submit = m2p_hw_submit; | |
1315 | edma->hw_interrupt = m2p_hw_interrupt; | |
1316 | } | |
1317 | ||
1318 | ret = dma_async_device_register(dma_dev); | |
1319 | if (unlikely(ret)) { | |
1320 | for (i = 0; i < edma->num_channels; i++) { | |
1321 | struct ep93xx_dma_chan *edmac = &edma->channels[i]; | |
1322 | if (!IS_ERR_OR_NULL(edmac->clk)) | |
1323 | clk_put(edmac->clk); | |
1324 | } | |
1325 | kfree(edma); | |
1326 | } else { | |
1327 | dev_info(dma_dev->dev, "EP93xx M2%s DMA ready\n", | |
1328 | edma->m2m ? "M" : "P"); | |
1329 | } | |
1330 | ||
1331 | return ret; | |
1332 | } | |
1333 | ||
1334 | static struct platform_device_id ep93xx_dma_driver_ids[] = { | |
1335 | { "ep93xx-dma-m2p", 0 }, | |
1336 | { "ep93xx-dma-m2m", 1 }, | |
1337 | { }, | |
1338 | }; | |
1339 | ||
1340 | static struct platform_driver ep93xx_dma_driver = { | |
1341 | .driver = { | |
1342 | .name = "ep93xx-dma", | |
1343 | }, | |
1344 | .id_table = ep93xx_dma_driver_ids, | |
1345 | }; | |
1346 | ||
1347 | static int __init ep93xx_dma_module_init(void) | |
1348 | { | |
1349 | return platform_driver_probe(&ep93xx_dma_driver, ep93xx_dma_probe); | |
1350 | } | |
1351 | subsys_initcall(ep93xx_dma_module_init); | |
1352 | ||
1353 | MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>"); | |
1354 | MODULE_DESCRIPTION("EP93xx DMA driver"); | |
1355 | MODULE_LICENSE("GPL"); |