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87244fe5 LP |
1 | /* |
2 | * Renesas R-Car Gen2 DMA Controller Driver | |
3 | * | |
4 | * Copyright (C) 2014 Renesas Electronics Inc. | |
5 | * | |
6 | * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com> | |
7 | * | |
8 | * This is free software; you can redistribute it and/or modify | |
9 | * it under the terms of version 2 of the GNU General Public License as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
ccadee9b | 13 | #include <linux/dma-mapping.h> |
87244fe5 LP |
14 | #include <linux/dmaengine.h> |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/list.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/mutex.h> | |
19 | #include <linux/of.h> | |
20 | #include <linux/of_dma.h> | |
21 | #include <linux/of_platform.h> | |
22 | #include <linux/platform_device.h> | |
23 | #include <linux/pm_runtime.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/spinlock.h> | |
26 | ||
27 | #include "../dmaengine.h" | |
28 | ||
29 | /* | |
30 | * struct rcar_dmac_xfer_chunk - Descriptor for a hardware transfer | |
31 | * @node: entry in the parent's chunks list | |
32 | * @src_addr: device source address | |
33 | * @dst_addr: device destination address | |
34 | * @size: transfer size in bytes | |
35 | */ | |
36 | struct rcar_dmac_xfer_chunk { | |
37 | struct list_head node; | |
38 | ||
39 | dma_addr_t src_addr; | |
40 | dma_addr_t dst_addr; | |
41 | u32 size; | |
42 | }; | |
43 | ||
ccadee9b LP |
44 | /* |
45 | * struct rcar_dmac_hw_desc - Hardware descriptor for a transfer chunk | |
46 | * @sar: value of the SAR register (source address) | |
47 | * @dar: value of the DAR register (destination address) | |
48 | * @tcr: value of the TCR register (transfer count) | |
49 | */ | |
50 | struct rcar_dmac_hw_desc { | |
51 | u32 sar; | |
52 | u32 dar; | |
53 | u32 tcr; | |
54 | u32 reserved; | |
55 | } __attribute__((__packed__)); | |
56 | ||
87244fe5 LP |
57 | /* |
58 | * struct rcar_dmac_desc - R-Car Gen2 DMA Transfer Descriptor | |
59 | * @async_tx: base DMA asynchronous transaction descriptor | |
60 | * @direction: direction of the DMA transfer | |
61 | * @xfer_shift: log2 of the transfer size | |
62 | * @chcr: value of the channel configuration register for this transfer | |
63 | * @node: entry in the channel's descriptors lists | |
64 | * @chunks: list of transfer chunks for this transfer | |
65 | * @running: the transfer chunk being currently processed | |
ccadee9b | 66 | * @nchunks: number of transfer chunks for this transfer |
1ed1315f | 67 | * @hwdescs.use: whether the transfer descriptor uses hardware descriptors |
ccadee9b LP |
68 | * @hwdescs.mem: hardware descriptors memory for the transfer |
69 | * @hwdescs.dma: device address of the hardware descriptors memory | |
70 | * @hwdescs.size: size of the hardware descriptors in bytes | |
87244fe5 LP |
71 | * @size: transfer size in bytes |
72 | * @cyclic: when set indicates that the DMA transfer is cyclic | |
73 | */ | |
74 | struct rcar_dmac_desc { | |
75 | struct dma_async_tx_descriptor async_tx; | |
76 | enum dma_transfer_direction direction; | |
77 | unsigned int xfer_shift; | |
78 | u32 chcr; | |
79 | ||
80 | struct list_head node; | |
81 | struct list_head chunks; | |
82 | struct rcar_dmac_xfer_chunk *running; | |
ccadee9b LP |
83 | unsigned int nchunks; |
84 | ||
85 | struct { | |
1ed1315f | 86 | bool use; |
ccadee9b LP |
87 | struct rcar_dmac_hw_desc *mem; |
88 | dma_addr_t dma; | |
89 | size_t size; | |
90 | } hwdescs; | |
87244fe5 LP |
91 | |
92 | unsigned int size; | |
93 | bool cyclic; | |
94 | }; | |
95 | ||
96 | #define to_rcar_dmac_desc(d) container_of(d, struct rcar_dmac_desc, async_tx) | |
97 | ||
98 | /* | |
99 | * struct rcar_dmac_desc_page - One page worth of descriptors | |
100 | * @node: entry in the channel's pages list | |
101 | * @descs: array of DMA descriptors | |
102 | * @chunks: array of transfer chunk descriptors | |
103 | */ | |
104 | struct rcar_dmac_desc_page { | |
105 | struct list_head node; | |
106 | ||
107 | union { | |
108 | struct rcar_dmac_desc descs[0]; | |
109 | struct rcar_dmac_xfer_chunk chunks[0]; | |
110 | }; | |
111 | }; | |
112 | ||
113 | #define RCAR_DMAC_DESCS_PER_PAGE \ | |
114 | ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, descs)) / \ | |
115 | sizeof(struct rcar_dmac_desc)) | |
116 | #define RCAR_DMAC_XFER_CHUNKS_PER_PAGE \ | |
117 | ((PAGE_SIZE - offsetof(struct rcar_dmac_desc_page, chunks)) / \ | |
118 | sizeof(struct rcar_dmac_xfer_chunk)) | |
119 | ||
120 | /* | |
121 | * struct rcar_dmac_chan - R-Car Gen2 DMA Controller Channel | |
122 | * @chan: base DMA channel object | |
123 | * @iomem: channel I/O memory base | |
124 | * @index: index of this channel in the controller | |
125 | * @src_xfer_size: size (in bytes) of hardware transfers on the source side | |
126 | * @dst_xfer_size: size (in bytes) of hardware transfers on the destination side | |
127 | * @src_slave_addr: slave source memory address | |
128 | * @dst_slave_addr: slave destination memory address | |
129 | * @mid_rid: hardware MID/RID for the DMA client using this channel | |
130 | * @lock: protects the channel CHCR register and the desc members | |
131 | * @desc.free: list of free descriptors | |
132 | * @desc.pending: list of pending descriptors (submitted with tx_submit) | |
133 | * @desc.active: list of active descriptors (activated with issue_pending) | |
134 | * @desc.done: list of completed descriptors | |
135 | * @desc.wait: list of descriptors waiting for an ack | |
136 | * @desc.running: the descriptor being processed (a member of the active list) | |
137 | * @desc.chunks_free: list of free transfer chunk descriptors | |
138 | * @desc.pages: list of pages used by allocated descriptors | |
139 | */ | |
140 | struct rcar_dmac_chan { | |
141 | struct dma_chan chan; | |
142 | void __iomem *iomem; | |
143 | unsigned int index; | |
144 | ||
145 | unsigned int src_xfer_size; | |
146 | unsigned int dst_xfer_size; | |
147 | dma_addr_t src_slave_addr; | |
148 | dma_addr_t dst_slave_addr; | |
149 | int mid_rid; | |
150 | ||
151 | spinlock_t lock; | |
152 | ||
153 | struct { | |
154 | struct list_head free; | |
155 | struct list_head pending; | |
156 | struct list_head active; | |
157 | struct list_head done; | |
158 | struct list_head wait; | |
159 | struct rcar_dmac_desc *running; | |
160 | ||
161 | struct list_head chunks_free; | |
162 | ||
163 | struct list_head pages; | |
164 | } desc; | |
165 | }; | |
166 | ||
167 | #define to_rcar_dmac_chan(c) container_of(c, struct rcar_dmac_chan, chan) | |
168 | ||
169 | /* | |
170 | * struct rcar_dmac - R-Car Gen2 DMA Controller | |
171 | * @engine: base DMA engine object | |
172 | * @dev: the hardware device | |
173 | * @iomem: remapped I/O memory base | |
174 | * @n_channels: number of available channels | |
175 | * @channels: array of DMAC channels | |
176 | * @modules: bitmask of client modules in use | |
177 | */ | |
178 | struct rcar_dmac { | |
179 | struct dma_device engine; | |
180 | struct device *dev; | |
181 | void __iomem *iomem; | |
182 | ||
183 | unsigned int n_channels; | |
184 | struct rcar_dmac_chan *channels; | |
185 | ||
186 | unsigned long modules[256 / BITS_PER_LONG]; | |
187 | }; | |
188 | ||
189 | #define to_rcar_dmac(d) container_of(d, struct rcar_dmac, engine) | |
190 | ||
191 | /* ----------------------------------------------------------------------------- | |
192 | * Registers | |
193 | */ | |
194 | ||
195 | #define RCAR_DMAC_CHAN_OFFSET(i) (0x8000 + 0x80 * (i)) | |
196 | ||
197 | #define RCAR_DMAISTA 0x0020 | |
198 | #define RCAR_DMASEC 0x0030 | |
199 | #define RCAR_DMAOR 0x0060 | |
200 | #define RCAR_DMAOR_PRI_FIXED (0 << 8) | |
201 | #define RCAR_DMAOR_PRI_ROUND_ROBIN (3 << 8) | |
202 | #define RCAR_DMAOR_AE (1 << 2) | |
203 | #define RCAR_DMAOR_DME (1 << 0) | |
204 | #define RCAR_DMACHCLR 0x0080 | |
205 | #define RCAR_DMADPSEC 0x00a0 | |
206 | ||
207 | #define RCAR_DMASAR 0x0000 | |
208 | #define RCAR_DMADAR 0x0004 | |
209 | #define RCAR_DMATCR 0x0008 | |
210 | #define RCAR_DMATCR_MASK 0x00ffffff | |
211 | #define RCAR_DMATSR 0x0028 | |
212 | #define RCAR_DMACHCR 0x000c | |
213 | #define RCAR_DMACHCR_CAE (1 << 31) | |
214 | #define RCAR_DMACHCR_CAIE (1 << 30) | |
215 | #define RCAR_DMACHCR_DPM_DISABLED (0 << 28) | |
216 | #define RCAR_DMACHCR_DPM_ENABLED (1 << 28) | |
217 | #define RCAR_DMACHCR_DPM_REPEAT (2 << 28) | |
218 | #define RCAR_DMACHCR_DPM_INFINITE (3 << 28) | |
219 | #define RCAR_DMACHCR_RPT_SAR (1 << 27) | |
220 | #define RCAR_DMACHCR_RPT_DAR (1 << 26) | |
221 | #define RCAR_DMACHCR_RPT_TCR (1 << 25) | |
222 | #define RCAR_DMACHCR_DPB (1 << 22) | |
223 | #define RCAR_DMACHCR_DSE (1 << 19) | |
224 | #define RCAR_DMACHCR_DSIE (1 << 18) | |
225 | #define RCAR_DMACHCR_TS_1B ((0 << 20) | (0 << 3)) | |
226 | #define RCAR_DMACHCR_TS_2B ((0 << 20) | (1 << 3)) | |
227 | #define RCAR_DMACHCR_TS_4B ((0 << 20) | (2 << 3)) | |
228 | #define RCAR_DMACHCR_TS_16B ((0 << 20) | (3 << 3)) | |
229 | #define RCAR_DMACHCR_TS_32B ((1 << 20) | (0 << 3)) | |
230 | #define RCAR_DMACHCR_TS_64B ((1 << 20) | (1 << 3)) | |
231 | #define RCAR_DMACHCR_TS_8B ((1 << 20) | (3 << 3)) | |
232 | #define RCAR_DMACHCR_DM_FIXED (0 << 14) | |
233 | #define RCAR_DMACHCR_DM_INC (1 << 14) | |
234 | #define RCAR_DMACHCR_DM_DEC (2 << 14) | |
235 | #define RCAR_DMACHCR_SM_FIXED (0 << 12) | |
236 | #define RCAR_DMACHCR_SM_INC (1 << 12) | |
237 | #define RCAR_DMACHCR_SM_DEC (2 << 12) | |
238 | #define RCAR_DMACHCR_RS_AUTO (4 << 8) | |
239 | #define RCAR_DMACHCR_RS_DMARS (8 << 8) | |
240 | #define RCAR_DMACHCR_IE (1 << 2) | |
241 | #define RCAR_DMACHCR_TE (1 << 1) | |
242 | #define RCAR_DMACHCR_DE (1 << 0) | |
243 | #define RCAR_DMATCRB 0x0018 | |
244 | #define RCAR_DMATSRB 0x0038 | |
245 | #define RCAR_DMACHCRB 0x001c | |
246 | #define RCAR_DMACHCRB_DCNT(n) ((n) << 24) | |
ccadee9b LP |
247 | #define RCAR_DMACHCRB_DPTR_MASK (0xff << 16) |
248 | #define RCAR_DMACHCRB_DPTR_SHIFT 16 | |
87244fe5 LP |
249 | #define RCAR_DMACHCRB_DRST (1 << 15) |
250 | #define RCAR_DMACHCRB_DTS (1 << 8) | |
251 | #define RCAR_DMACHCRB_SLM_NORMAL (0 << 4) | |
252 | #define RCAR_DMACHCRB_SLM_CLK(n) ((8 | (n)) << 4) | |
253 | #define RCAR_DMACHCRB_PRI(n) ((n) << 0) | |
254 | #define RCAR_DMARS 0x0040 | |
255 | #define RCAR_DMABUFCR 0x0048 | |
256 | #define RCAR_DMABUFCR_MBU(n) ((n) << 16) | |
257 | #define RCAR_DMABUFCR_ULB(n) ((n) << 0) | |
258 | #define RCAR_DMADPBASE 0x0050 | |
259 | #define RCAR_DMADPBASE_MASK 0xfffffff0 | |
260 | #define RCAR_DMADPBASE_SEL (1 << 0) | |
261 | #define RCAR_DMADPCR 0x0054 | |
262 | #define RCAR_DMADPCR_DIPT(n) ((n) << 24) | |
263 | #define RCAR_DMAFIXSAR 0x0010 | |
264 | #define RCAR_DMAFIXDAR 0x0014 | |
265 | #define RCAR_DMAFIXDPBASE 0x0060 | |
266 | ||
267 | /* Hardcode the MEMCPY transfer size to 4 bytes. */ | |
268 | #define RCAR_DMAC_MEMCPY_XFER_SIZE 4 | |
269 | ||
270 | /* ----------------------------------------------------------------------------- | |
271 | * Device access | |
272 | */ | |
273 | ||
274 | static void rcar_dmac_write(struct rcar_dmac *dmac, u32 reg, u32 data) | |
275 | { | |
276 | if (reg == RCAR_DMAOR) | |
277 | writew(data, dmac->iomem + reg); | |
278 | else | |
279 | writel(data, dmac->iomem + reg); | |
280 | } | |
281 | ||
282 | static u32 rcar_dmac_read(struct rcar_dmac *dmac, u32 reg) | |
283 | { | |
284 | if (reg == RCAR_DMAOR) | |
285 | return readw(dmac->iomem + reg); | |
286 | else | |
287 | return readl(dmac->iomem + reg); | |
288 | } | |
289 | ||
290 | static u32 rcar_dmac_chan_read(struct rcar_dmac_chan *chan, u32 reg) | |
291 | { | |
292 | if (reg == RCAR_DMARS) | |
293 | return readw(chan->iomem + reg); | |
294 | else | |
295 | return readl(chan->iomem + reg); | |
296 | } | |
297 | ||
298 | static void rcar_dmac_chan_write(struct rcar_dmac_chan *chan, u32 reg, u32 data) | |
299 | { | |
300 | if (reg == RCAR_DMARS) | |
301 | writew(data, chan->iomem + reg); | |
302 | else | |
303 | writel(data, chan->iomem + reg); | |
304 | } | |
305 | ||
306 | /* ----------------------------------------------------------------------------- | |
307 | * Initialization and configuration | |
308 | */ | |
309 | ||
310 | static bool rcar_dmac_chan_is_busy(struct rcar_dmac_chan *chan) | |
311 | { | |
312 | u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); | |
313 | ||
314 | return (chcr & (RCAR_DMACHCR_DE | RCAR_DMACHCR_TE)) == RCAR_DMACHCR_DE; | |
315 | } | |
316 | ||
317 | static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan) | |
318 | { | |
319 | struct rcar_dmac_desc *desc = chan->desc.running; | |
ccadee9b | 320 | u32 chcr = desc->chcr; |
87244fe5 LP |
321 | |
322 | WARN_ON_ONCE(rcar_dmac_chan_is_busy(chan)); | |
323 | ||
ccadee9b LP |
324 | if (chan->mid_rid >= 0) |
325 | rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid); | |
326 | ||
1ed1315f | 327 | if (desc->hwdescs.use) { |
ccadee9b LP |
328 | dev_dbg(chan->chan.device->dev, |
329 | "chan%u: queue desc %p: %u@%pad\n", | |
330 | chan->index, desc, desc->nchunks, &desc->hwdescs.dma); | |
331 | ||
87244fe5 | 332 | #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT |
ccadee9b LP |
333 | rcar_dmac_chan_write(chan, RCAR_DMAFIXDPBASE, |
334 | desc->hwdescs.dma >> 32); | |
87244fe5 | 335 | #endif |
ccadee9b LP |
336 | rcar_dmac_chan_write(chan, RCAR_DMADPBASE, |
337 | (desc->hwdescs.dma & 0xfffffff0) | | |
338 | RCAR_DMADPBASE_SEL); | |
339 | rcar_dmac_chan_write(chan, RCAR_DMACHCRB, | |
340 | RCAR_DMACHCRB_DCNT(desc->nchunks - 1) | | |
341 | RCAR_DMACHCRB_DRST); | |
87244fe5 | 342 | |
ccadee9b LP |
343 | /* |
344 | * Program the descriptor stage interrupt to occur after the end | |
345 | * of the first stage. | |
346 | */ | |
347 | rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(1)); | |
348 | ||
349 | chcr |= RCAR_DMACHCR_RPT_SAR | RCAR_DMACHCR_RPT_DAR | |
350 | | RCAR_DMACHCR_RPT_TCR | RCAR_DMACHCR_DPB; | |
351 | ||
352 | /* | |
353 | * If the descriptor isn't cyclic enable normal descriptor mode | |
354 | * and the transfer completion interrupt. | |
355 | */ | |
356 | if (!desc->cyclic) | |
357 | chcr |= RCAR_DMACHCR_DPM_ENABLED | RCAR_DMACHCR_IE; | |
358 | /* | |
359 | * If the descriptor is cyclic and has a callback enable the | |
360 | * descriptor stage interrupt in infinite repeat mode. | |
361 | */ | |
362 | else if (desc->async_tx.callback) | |
363 | chcr |= RCAR_DMACHCR_DPM_INFINITE | RCAR_DMACHCR_DSIE; | |
364 | /* | |
365 | * Otherwise just select infinite repeat mode without any | |
366 | * interrupt. | |
367 | */ | |
368 | else | |
369 | chcr |= RCAR_DMACHCR_DPM_INFINITE; | |
370 | } else { | |
371 | struct rcar_dmac_xfer_chunk *chunk = desc->running; | |
87244fe5 | 372 | |
ccadee9b LP |
373 | dev_dbg(chan->chan.device->dev, |
374 | "chan%u: queue chunk %p: %u@%pad -> %pad\n", | |
375 | chan->index, chunk, chunk->size, &chunk->src_addr, | |
376 | &chunk->dst_addr); | |
87244fe5 | 377 | |
ccadee9b LP |
378 | #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT |
379 | rcar_dmac_chan_write(chan, RCAR_DMAFIXSAR, | |
380 | chunk->src_addr >> 32); | |
381 | rcar_dmac_chan_write(chan, RCAR_DMAFIXDAR, | |
382 | chunk->dst_addr >> 32); | |
383 | #endif | |
384 | rcar_dmac_chan_write(chan, RCAR_DMASAR, | |
385 | chunk->src_addr & 0xffffffff); | |
386 | rcar_dmac_chan_write(chan, RCAR_DMADAR, | |
387 | chunk->dst_addr & 0xffffffff); | |
388 | rcar_dmac_chan_write(chan, RCAR_DMATCR, | |
389 | chunk->size >> desc->xfer_shift); | |
390 | ||
391 | chcr |= RCAR_DMACHCR_DPM_DISABLED | RCAR_DMACHCR_IE; | |
392 | } | |
393 | ||
394 | rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr | RCAR_DMACHCR_DE); | |
87244fe5 LP |
395 | } |
396 | ||
397 | static int rcar_dmac_init(struct rcar_dmac *dmac) | |
398 | { | |
399 | u16 dmaor; | |
400 | ||
401 | /* Clear all channels and enable the DMAC globally. */ | |
402 | rcar_dmac_write(dmac, RCAR_DMACHCLR, 0x7fff); | |
403 | rcar_dmac_write(dmac, RCAR_DMAOR, | |
404 | RCAR_DMAOR_PRI_FIXED | RCAR_DMAOR_DME); | |
405 | ||
406 | dmaor = rcar_dmac_read(dmac, RCAR_DMAOR); | |
407 | if ((dmaor & (RCAR_DMAOR_AE | RCAR_DMAOR_DME)) != RCAR_DMAOR_DME) { | |
408 | dev_warn(dmac->dev, "DMAOR initialization failed.\n"); | |
409 | return -EIO; | |
410 | } | |
411 | ||
412 | return 0; | |
413 | } | |
414 | ||
415 | /* ----------------------------------------------------------------------------- | |
416 | * Descriptors submission | |
417 | */ | |
418 | ||
419 | static dma_cookie_t rcar_dmac_tx_submit(struct dma_async_tx_descriptor *tx) | |
420 | { | |
421 | struct rcar_dmac_chan *chan = to_rcar_dmac_chan(tx->chan); | |
422 | struct rcar_dmac_desc *desc = to_rcar_dmac_desc(tx); | |
423 | unsigned long flags; | |
424 | dma_cookie_t cookie; | |
425 | ||
426 | spin_lock_irqsave(&chan->lock, flags); | |
427 | ||
428 | cookie = dma_cookie_assign(tx); | |
429 | ||
430 | dev_dbg(chan->chan.device->dev, "chan%u: submit #%d@%p\n", | |
431 | chan->index, tx->cookie, desc); | |
432 | ||
433 | list_add_tail(&desc->node, &chan->desc.pending); | |
434 | desc->running = list_first_entry(&desc->chunks, | |
435 | struct rcar_dmac_xfer_chunk, node); | |
436 | ||
437 | spin_unlock_irqrestore(&chan->lock, flags); | |
438 | ||
439 | return cookie; | |
440 | } | |
441 | ||
442 | /* ----------------------------------------------------------------------------- | |
443 | * Descriptors allocation and free | |
444 | */ | |
445 | ||
446 | /* | |
447 | * rcar_dmac_desc_alloc - Allocate a page worth of DMA descriptors | |
448 | * @chan: the DMA channel | |
449 | * @gfp: allocation flags | |
450 | */ | |
451 | static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) | |
452 | { | |
453 | struct rcar_dmac_desc_page *page; | |
454 | LIST_HEAD(list); | |
455 | unsigned int i; | |
456 | ||
457 | page = (void *)get_zeroed_page(gfp); | |
458 | if (!page) | |
459 | return -ENOMEM; | |
460 | ||
461 | for (i = 0; i < RCAR_DMAC_DESCS_PER_PAGE; ++i) { | |
462 | struct rcar_dmac_desc *desc = &page->descs[i]; | |
463 | ||
464 | dma_async_tx_descriptor_init(&desc->async_tx, &chan->chan); | |
465 | desc->async_tx.tx_submit = rcar_dmac_tx_submit; | |
466 | INIT_LIST_HEAD(&desc->chunks); | |
467 | ||
468 | list_add_tail(&desc->node, &list); | |
469 | } | |
470 | ||
471 | spin_lock_irq(&chan->lock); | |
472 | list_splice_tail(&list, &chan->desc.free); | |
473 | list_add_tail(&page->node, &chan->desc.pages); | |
474 | spin_unlock_irq(&chan->lock); | |
475 | ||
476 | return 0; | |
477 | } | |
478 | ||
479 | /* | |
480 | * rcar_dmac_desc_put - Release a DMA transfer descriptor | |
481 | * @chan: the DMA channel | |
482 | * @desc: the descriptor | |
483 | * | |
484 | * Put the descriptor and its transfer chunk descriptors back in the channel's | |
1ed1315f LP |
485 | * free descriptors lists. The descriptor's chunks list will be reinitialized to |
486 | * an empty list as a result. | |
87244fe5 | 487 | * |
ccadee9b LP |
488 | * The descriptor must have been removed from the channel's lists before calling |
489 | * this function. | |
87244fe5 | 490 | * |
ccadee9b | 491 | * Locking: Must be called in non-atomic context. |
87244fe5 LP |
492 | */ |
493 | static void rcar_dmac_desc_put(struct rcar_dmac_chan *chan, | |
494 | struct rcar_dmac_desc *desc) | |
495 | { | |
ccadee9b | 496 | spin_lock_irq(&chan->lock); |
87244fe5 LP |
497 | list_splice_tail_init(&desc->chunks, &chan->desc.chunks_free); |
498 | list_add_tail(&desc->node, &chan->desc.free); | |
ccadee9b | 499 | spin_unlock_irq(&chan->lock); |
87244fe5 LP |
500 | } |
501 | ||
502 | static void rcar_dmac_desc_recycle_acked(struct rcar_dmac_chan *chan) | |
503 | { | |
504 | struct rcar_dmac_desc *desc, *_desc; | |
ccadee9b | 505 | LIST_HEAD(list); |
87244fe5 | 506 | |
ccadee9b LP |
507 | /* |
508 | * We have to temporarily move all descriptors from the wait list to a | |
509 | * local list as iterating over the wait list, even with | |
510 | * list_for_each_entry_safe, isn't safe if we release the channel lock | |
511 | * around the rcar_dmac_desc_put() call. | |
512 | */ | |
513 | spin_lock_irq(&chan->lock); | |
514 | list_splice_init(&chan->desc.wait, &list); | |
515 | spin_unlock_irq(&chan->lock); | |
516 | ||
517 | list_for_each_entry_safe(desc, _desc, &list, node) { | |
87244fe5 LP |
518 | if (async_tx_test_ack(&desc->async_tx)) { |
519 | list_del(&desc->node); | |
520 | rcar_dmac_desc_put(chan, desc); | |
521 | } | |
522 | } | |
ccadee9b LP |
523 | |
524 | if (list_empty(&list)) | |
525 | return; | |
526 | ||
527 | /* Put the remaining descriptors back in the wait list. */ | |
528 | spin_lock_irq(&chan->lock); | |
529 | list_splice(&list, &chan->desc.wait); | |
530 | spin_unlock_irq(&chan->lock); | |
87244fe5 LP |
531 | } |
532 | ||
533 | /* | |
534 | * rcar_dmac_desc_get - Allocate a descriptor for a DMA transfer | |
535 | * @chan: the DMA channel | |
536 | * | |
537 | * Locking: This function must be called in a non-atomic context. | |
538 | * | |
539 | * Return: A pointer to the allocated descriptor or NULL if no descriptor can | |
540 | * be allocated. | |
541 | */ | |
542 | static struct rcar_dmac_desc *rcar_dmac_desc_get(struct rcar_dmac_chan *chan) | |
543 | { | |
544 | struct rcar_dmac_desc *desc; | |
545 | int ret; | |
546 | ||
87244fe5 LP |
547 | /* Recycle acked descriptors before attempting allocation. */ |
548 | rcar_dmac_desc_recycle_acked(chan); | |
549 | ||
ccadee9b LP |
550 | spin_lock_irq(&chan->lock); |
551 | ||
87244fe5 LP |
552 | do { |
553 | if (list_empty(&chan->desc.free)) { | |
554 | /* | |
555 | * No free descriptors, allocate a page worth of them | |
556 | * and try again, as someone else could race us to get | |
557 | * the newly allocated descriptors. If the allocation | |
558 | * fails return an error. | |
559 | */ | |
560 | spin_unlock_irq(&chan->lock); | |
561 | ret = rcar_dmac_desc_alloc(chan, GFP_NOWAIT); | |
562 | if (ret < 0) | |
563 | return NULL; | |
564 | spin_lock_irq(&chan->lock); | |
565 | continue; | |
566 | } | |
567 | ||
568 | desc = list_first_entry(&chan->desc.free, struct rcar_dmac_desc, | |
569 | node); | |
570 | list_del(&desc->node); | |
571 | } while (!desc); | |
572 | ||
573 | spin_unlock_irq(&chan->lock); | |
574 | ||
575 | return desc; | |
576 | } | |
577 | ||
578 | /* | |
579 | * rcar_dmac_xfer_chunk_alloc - Allocate a page worth of transfer chunks | |
580 | * @chan: the DMA channel | |
581 | * @gfp: allocation flags | |
582 | */ | |
583 | static int rcar_dmac_xfer_chunk_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) | |
584 | { | |
585 | struct rcar_dmac_desc_page *page; | |
586 | LIST_HEAD(list); | |
587 | unsigned int i; | |
588 | ||
589 | page = (void *)get_zeroed_page(gfp); | |
590 | if (!page) | |
591 | return -ENOMEM; | |
592 | ||
593 | for (i = 0; i < RCAR_DMAC_XFER_CHUNKS_PER_PAGE; ++i) { | |
594 | struct rcar_dmac_xfer_chunk *chunk = &page->chunks[i]; | |
595 | ||
596 | list_add_tail(&chunk->node, &list); | |
597 | } | |
598 | ||
599 | spin_lock_irq(&chan->lock); | |
600 | list_splice_tail(&list, &chan->desc.chunks_free); | |
601 | list_add_tail(&page->node, &chan->desc.pages); | |
602 | spin_unlock_irq(&chan->lock); | |
603 | ||
604 | return 0; | |
605 | } | |
606 | ||
607 | /* | |
608 | * rcar_dmac_xfer_chunk_get - Allocate a transfer chunk for a DMA transfer | |
609 | * @chan: the DMA channel | |
610 | * | |
611 | * Locking: This function must be called in a non-atomic context. | |
612 | * | |
613 | * Return: A pointer to the allocated transfer chunk descriptor or NULL if no | |
614 | * descriptor can be allocated. | |
615 | */ | |
616 | static struct rcar_dmac_xfer_chunk * | |
617 | rcar_dmac_xfer_chunk_get(struct rcar_dmac_chan *chan) | |
618 | { | |
619 | struct rcar_dmac_xfer_chunk *chunk; | |
620 | int ret; | |
621 | ||
622 | spin_lock_irq(&chan->lock); | |
623 | ||
624 | do { | |
625 | if (list_empty(&chan->desc.chunks_free)) { | |
626 | /* | |
627 | * No free descriptors, allocate a page worth of them | |
628 | * and try again, as someone else could race us to get | |
629 | * the newly allocated descriptors. If the allocation | |
630 | * fails return an error. | |
631 | */ | |
632 | spin_unlock_irq(&chan->lock); | |
633 | ret = rcar_dmac_xfer_chunk_alloc(chan, GFP_NOWAIT); | |
634 | if (ret < 0) | |
635 | return NULL; | |
636 | spin_lock_irq(&chan->lock); | |
637 | continue; | |
638 | } | |
639 | ||
640 | chunk = list_first_entry(&chan->desc.chunks_free, | |
641 | struct rcar_dmac_xfer_chunk, node); | |
642 | list_del(&chunk->node); | |
643 | } while (!chunk); | |
644 | ||
645 | spin_unlock_irq(&chan->lock); | |
646 | ||
647 | return chunk; | |
648 | } | |
649 | ||
1ed1315f LP |
650 | static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan, |
651 | struct rcar_dmac_desc *desc, size_t size) | |
652 | { | |
653 | /* | |
654 | * dma_alloc_coherent() allocates memory in page size increments. To | |
655 | * avoid reallocating the hardware descriptors when the allocated size | |
656 | * wouldn't change align the requested size to a multiple of the page | |
657 | * size. | |
658 | */ | |
659 | size = PAGE_ALIGN(size); | |
660 | ||
661 | if (desc->hwdescs.size == size) | |
662 | return; | |
663 | ||
664 | if (desc->hwdescs.mem) { | |
665 | dma_free_coherent(NULL, desc->hwdescs.size, desc->hwdescs.mem, | |
666 | desc->hwdescs.dma); | |
667 | desc->hwdescs.mem = NULL; | |
668 | desc->hwdescs.size = 0; | |
669 | } | |
670 | ||
671 | if (!size) | |
672 | return; | |
673 | ||
674 | desc->hwdescs.mem = dma_alloc_coherent(NULL, size, &desc->hwdescs.dma, | |
675 | GFP_NOWAIT); | |
676 | if (!desc->hwdescs.mem) | |
677 | return; | |
678 | ||
679 | desc->hwdescs.size = size; | |
680 | } | |
681 | ||
682 | static void rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan, | |
683 | struct rcar_dmac_desc *desc) | |
ccadee9b LP |
684 | { |
685 | struct rcar_dmac_xfer_chunk *chunk; | |
686 | struct rcar_dmac_hw_desc *hwdesc; | |
ccadee9b | 687 | |
1ed1315f LP |
688 | rcar_dmac_realloc_hwdesc(chan, desc, desc->nchunks * sizeof(*hwdesc)); |
689 | ||
690 | hwdesc = desc->hwdescs.mem; | |
ccadee9b LP |
691 | if (!hwdesc) |
692 | return; | |
693 | ||
ccadee9b LP |
694 | list_for_each_entry(chunk, &desc->chunks, node) { |
695 | hwdesc->sar = chunk->src_addr; | |
696 | hwdesc->dar = chunk->dst_addr; | |
697 | hwdesc->tcr = chunk->size >> desc->xfer_shift; | |
698 | hwdesc++; | |
699 | } | |
700 | } | |
701 | ||
87244fe5 LP |
702 | /* ----------------------------------------------------------------------------- |
703 | * Stop and reset | |
704 | */ | |
705 | ||
706 | static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) | |
707 | { | |
708 | u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); | |
709 | ||
ccadee9b LP |
710 | chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE | |
711 | RCAR_DMACHCR_TE | RCAR_DMACHCR_DE); | |
87244fe5 LP |
712 | rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr); |
713 | } | |
714 | ||
715 | static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan) | |
716 | { | |
717 | struct rcar_dmac_desc *desc, *_desc; | |
718 | unsigned long flags; | |
719 | LIST_HEAD(descs); | |
720 | ||
721 | spin_lock_irqsave(&chan->lock, flags); | |
722 | ||
723 | /* Move all non-free descriptors to the local lists. */ | |
724 | list_splice_init(&chan->desc.pending, &descs); | |
725 | list_splice_init(&chan->desc.active, &descs); | |
726 | list_splice_init(&chan->desc.done, &descs); | |
727 | list_splice_init(&chan->desc.wait, &descs); | |
728 | ||
729 | chan->desc.running = NULL; | |
730 | ||
731 | spin_unlock_irqrestore(&chan->lock, flags); | |
732 | ||
733 | list_for_each_entry_safe(desc, _desc, &descs, node) { | |
734 | list_del(&desc->node); | |
735 | rcar_dmac_desc_put(chan, desc); | |
736 | } | |
737 | } | |
738 | ||
739 | static void rcar_dmac_stop(struct rcar_dmac *dmac) | |
740 | { | |
741 | rcar_dmac_write(dmac, RCAR_DMAOR, 0); | |
742 | } | |
743 | ||
744 | static void rcar_dmac_abort(struct rcar_dmac *dmac) | |
745 | { | |
746 | unsigned int i; | |
747 | ||
748 | /* Stop all channels. */ | |
749 | for (i = 0; i < dmac->n_channels; ++i) { | |
750 | struct rcar_dmac_chan *chan = &dmac->channels[i]; | |
751 | ||
752 | /* Stop and reinitialize the channel. */ | |
753 | spin_lock(&chan->lock); | |
754 | rcar_dmac_chan_halt(chan); | |
755 | spin_unlock(&chan->lock); | |
756 | ||
757 | rcar_dmac_chan_reinit(chan); | |
758 | } | |
759 | } | |
760 | ||
761 | /* ----------------------------------------------------------------------------- | |
762 | * Descriptors preparation | |
763 | */ | |
764 | ||
765 | static void rcar_dmac_chan_configure_desc(struct rcar_dmac_chan *chan, | |
766 | struct rcar_dmac_desc *desc) | |
767 | { | |
768 | static const u32 chcr_ts[] = { | |
769 | RCAR_DMACHCR_TS_1B, RCAR_DMACHCR_TS_2B, | |
770 | RCAR_DMACHCR_TS_4B, RCAR_DMACHCR_TS_8B, | |
771 | RCAR_DMACHCR_TS_16B, RCAR_DMACHCR_TS_32B, | |
772 | RCAR_DMACHCR_TS_64B, | |
773 | }; | |
774 | ||
775 | unsigned int xfer_size; | |
776 | u32 chcr; | |
777 | ||
778 | switch (desc->direction) { | |
779 | case DMA_DEV_TO_MEM: | |
780 | chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_FIXED | |
781 | | RCAR_DMACHCR_RS_DMARS; | |
782 | xfer_size = chan->src_xfer_size; | |
783 | break; | |
784 | ||
785 | case DMA_MEM_TO_DEV: | |
786 | chcr = RCAR_DMACHCR_DM_FIXED | RCAR_DMACHCR_SM_INC | |
787 | | RCAR_DMACHCR_RS_DMARS; | |
788 | xfer_size = chan->dst_xfer_size; | |
789 | break; | |
790 | ||
791 | case DMA_MEM_TO_MEM: | |
792 | default: | |
793 | chcr = RCAR_DMACHCR_DM_INC | RCAR_DMACHCR_SM_INC | |
794 | | RCAR_DMACHCR_RS_AUTO; | |
795 | xfer_size = RCAR_DMAC_MEMCPY_XFER_SIZE; | |
796 | break; | |
797 | } | |
798 | ||
799 | desc->xfer_shift = ilog2(xfer_size); | |
800 | desc->chcr = chcr | chcr_ts[desc->xfer_shift]; | |
801 | } | |
802 | ||
803 | /* | |
804 | * rcar_dmac_chan_prep_sg - prepare transfer descriptors from an SG list | |
805 | * | |
806 | * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also | |
807 | * converted to scatter-gather to guarantee consistent locking and a correct | |
808 | * list manipulation. For slave DMA direction carries the usual meaning, and, | |
809 | * logically, the SG list is RAM and the addr variable contains slave address, | |
810 | * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM | |
811 | * and the SG list contains only one element and points at the source buffer. | |
812 | */ | |
813 | static struct dma_async_tx_descriptor * | |
814 | rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl, | |
815 | unsigned int sg_len, dma_addr_t dev_addr, | |
816 | enum dma_transfer_direction dir, unsigned long dma_flags, | |
817 | bool cyclic) | |
818 | { | |
819 | struct rcar_dmac_xfer_chunk *chunk; | |
820 | struct rcar_dmac_desc *desc; | |
821 | struct scatterlist *sg; | |
ccadee9b | 822 | unsigned int nchunks = 0; |
87244fe5 LP |
823 | unsigned int max_chunk_size; |
824 | unsigned int full_size = 0; | |
ccadee9b | 825 | bool highmem = false; |
87244fe5 LP |
826 | unsigned int i; |
827 | ||
828 | desc = rcar_dmac_desc_get(chan); | |
829 | if (!desc) | |
830 | return NULL; | |
831 | ||
832 | desc->async_tx.flags = dma_flags; | |
833 | desc->async_tx.cookie = -EBUSY; | |
834 | ||
835 | desc->cyclic = cyclic; | |
836 | desc->direction = dir; | |
837 | ||
838 | rcar_dmac_chan_configure_desc(chan, desc); | |
839 | ||
840 | max_chunk_size = (RCAR_DMATCR_MASK + 1) << desc->xfer_shift; | |
841 | ||
842 | /* | |
843 | * Allocate and fill the transfer chunk descriptors. We own the only | |
844 | * reference to the DMA descriptor, there's no need for locking. | |
845 | */ | |
846 | for_each_sg(sgl, sg, sg_len, i) { | |
847 | dma_addr_t mem_addr = sg_dma_address(sg); | |
848 | unsigned int len = sg_dma_len(sg); | |
849 | ||
850 | full_size += len; | |
851 | ||
852 | while (len) { | |
853 | unsigned int size = min(len, max_chunk_size); | |
854 | ||
855 | #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT | |
856 | /* | |
857 | * Prevent individual transfers from crossing 4GB | |
858 | * boundaries. | |
859 | */ | |
860 | if (dev_addr >> 32 != (dev_addr + size - 1) >> 32) | |
861 | size = ALIGN(dev_addr, 1ULL << 32) - dev_addr; | |
862 | if (mem_addr >> 32 != (mem_addr + size - 1) >> 32) | |
863 | size = ALIGN(mem_addr, 1ULL << 32) - mem_addr; | |
ccadee9b LP |
864 | |
865 | /* | |
866 | * Check if either of the source or destination address | |
867 | * can't be expressed in 32 bits. If so we can't use | |
868 | * hardware descriptor lists. | |
869 | */ | |
870 | if (dev_addr >> 32 || mem_addr >> 32) | |
871 | highmem = true; | |
87244fe5 LP |
872 | #endif |
873 | ||
874 | chunk = rcar_dmac_xfer_chunk_get(chan); | |
875 | if (!chunk) { | |
876 | rcar_dmac_desc_put(chan, desc); | |
877 | return NULL; | |
878 | } | |
879 | ||
880 | if (dir == DMA_DEV_TO_MEM) { | |
881 | chunk->src_addr = dev_addr; | |
882 | chunk->dst_addr = mem_addr; | |
883 | } else { | |
884 | chunk->src_addr = mem_addr; | |
885 | chunk->dst_addr = dev_addr; | |
886 | } | |
887 | ||
888 | chunk->size = size; | |
889 | ||
890 | dev_dbg(chan->chan.device->dev, | |
891 | "chan%u: chunk %p/%p sgl %u@%p, %u/%u %pad -> %pad\n", | |
892 | chan->index, chunk, desc, i, sg, size, len, | |
893 | &chunk->src_addr, &chunk->dst_addr); | |
894 | ||
895 | mem_addr += size; | |
896 | if (dir == DMA_MEM_TO_MEM) | |
897 | dev_addr += size; | |
898 | ||
899 | len -= size; | |
900 | ||
901 | list_add_tail(&chunk->node, &desc->chunks); | |
ccadee9b | 902 | nchunks++; |
87244fe5 LP |
903 | } |
904 | } | |
905 | ||
ccadee9b | 906 | desc->nchunks = nchunks; |
87244fe5 LP |
907 | desc->size = full_size; |
908 | ||
ccadee9b LP |
909 | /* |
910 | * Use hardware descriptor lists if possible when more than one chunk | |
911 | * needs to be transferred (otherwise they don't make much sense). | |
912 | * | |
913 | * The highmem check currently covers the whole transfer. As an | |
914 | * optimization we could use descriptor lists for consecutive lowmem | |
915 | * chunks and direct manual mode for highmem chunks. Whether the | |
916 | * performance improvement would be significant enough compared to the | |
917 | * additional complexity remains to be investigated. | |
918 | */ | |
1ed1315f LP |
919 | desc->hwdescs.use = !highmem && nchunks > 1; |
920 | if (desc->hwdescs.use) | |
921 | rcar_dmac_fill_hwdesc(chan, desc); | |
ccadee9b | 922 | |
87244fe5 LP |
923 | return &desc->async_tx; |
924 | } | |
925 | ||
926 | /* ----------------------------------------------------------------------------- | |
927 | * DMA engine operations | |
928 | */ | |
929 | ||
930 | static int rcar_dmac_alloc_chan_resources(struct dma_chan *chan) | |
931 | { | |
932 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
933 | int ret; | |
934 | ||
935 | INIT_LIST_HEAD(&rchan->desc.free); | |
936 | INIT_LIST_HEAD(&rchan->desc.pending); | |
937 | INIT_LIST_HEAD(&rchan->desc.active); | |
938 | INIT_LIST_HEAD(&rchan->desc.done); | |
939 | INIT_LIST_HEAD(&rchan->desc.wait); | |
940 | INIT_LIST_HEAD(&rchan->desc.chunks_free); | |
941 | INIT_LIST_HEAD(&rchan->desc.pages); | |
942 | ||
943 | /* Preallocate descriptors. */ | |
944 | ret = rcar_dmac_xfer_chunk_alloc(rchan, GFP_KERNEL); | |
945 | if (ret < 0) | |
946 | return -ENOMEM; | |
947 | ||
948 | ret = rcar_dmac_desc_alloc(rchan, GFP_KERNEL); | |
949 | if (ret < 0) | |
950 | return -ENOMEM; | |
951 | ||
952 | return pm_runtime_get_sync(chan->device->dev); | |
953 | } | |
954 | ||
955 | static void rcar_dmac_free_chan_resources(struct dma_chan *chan) | |
956 | { | |
957 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
958 | struct rcar_dmac *dmac = to_rcar_dmac(chan->device); | |
959 | struct rcar_dmac_desc_page *page, *_page; | |
1ed1315f LP |
960 | struct rcar_dmac_desc *desc; |
961 | LIST_HEAD(list); | |
87244fe5 LP |
962 | |
963 | /* Protect against ISR */ | |
964 | spin_lock_irq(&rchan->lock); | |
965 | rcar_dmac_chan_halt(rchan); | |
966 | spin_unlock_irq(&rchan->lock); | |
967 | ||
968 | /* Now no new interrupts will occur */ | |
969 | ||
970 | if (rchan->mid_rid >= 0) { | |
971 | /* The caller is holding dma_list_mutex */ | |
972 | clear_bit(rchan->mid_rid, dmac->modules); | |
973 | rchan->mid_rid = -EINVAL; | |
974 | } | |
975 | ||
1ed1315f LP |
976 | list_splice(&rchan->desc.free, &list); |
977 | list_splice(&rchan->desc.pending, &list); | |
978 | list_splice(&rchan->desc.active, &list); | |
979 | list_splice(&rchan->desc.done, &list); | |
980 | list_splice(&rchan->desc.wait, &list); | |
981 | ||
982 | list_for_each_entry(desc, &list, node) | |
983 | rcar_dmac_realloc_hwdesc(rchan, desc, 0); | |
984 | ||
87244fe5 LP |
985 | list_for_each_entry_safe(page, _page, &rchan->desc.pages, node) { |
986 | list_del(&page->node); | |
987 | free_page((unsigned long)page); | |
988 | } | |
989 | ||
990 | pm_runtime_put(chan->device->dev); | |
991 | } | |
992 | ||
993 | static struct dma_async_tx_descriptor * | |
994 | rcar_dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dma_dest, | |
995 | dma_addr_t dma_src, size_t len, unsigned long flags) | |
996 | { | |
997 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
998 | struct scatterlist sgl; | |
999 | ||
1000 | if (!len) | |
1001 | return NULL; | |
1002 | ||
1003 | sg_init_table(&sgl, 1); | |
1004 | sg_set_page(&sgl, pfn_to_page(PFN_DOWN(dma_src)), len, | |
1005 | offset_in_page(dma_src)); | |
1006 | sg_dma_address(&sgl) = dma_src; | |
1007 | sg_dma_len(&sgl) = len; | |
1008 | ||
1009 | return rcar_dmac_chan_prep_sg(rchan, &sgl, 1, dma_dest, | |
1010 | DMA_MEM_TO_MEM, flags, false); | |
1011 | } | |
1012 | ||
1013 | static struct dma_async_tx_descriptor * | |
1014 | rcar_dmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, | |
1015 | unsigned int sg_len, enum dma_transfer_direction dir, | |
1016 | unsigned long flags, void *context) | |
1017 | { | |
1018 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
1019 | dma_addr_t dev_addr; | |
1020 | ||
1021 | /* Someone calling slave DMA on a generic channel? */ | |
1022 | if (rchan->mid_rid < 0 || !sg_len) { | |
1023 | dev_warn(chan->device->dev, | |
1024 | "%s: bad parameter: len=%d, id=%d\n", | |
1025 | __func__, sg_len, rchan->mid_rid); | |
1026 | return NULL; | |
1027 | } | |
1028 | ||
1029 | dev_addr = dir == DMA_DEV_TO_MEM | |
1030 | ? rchan->src_slave_addr : rchan->dst_slave_addr; | |
1031 | return rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr, | |
1032 | dir, flags, false); | |
1033 | } | |
1034 | ||
1035 | #define RCAR_DMAC_MAX_SG_LEN 32 | |
1036 | ||
1037 | static struct dma_async_tx_descriptor * | |
1038 | rcar_dmac_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, | |
1039 | size_t buf_len, size_t period_len, | |
1040 | enum dma_transfer_direction dir, unsigned long flags) | |
1041 | { | |
1042 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
1043 | struct dma_async_tx_descriptor *desc; | |
1044 | struct scatterlist *sgl; | |
1045 | dma_addr_t dev_addr; | |
1046 | unsigned int sg_len; | |
1047 | unsigned int i; | |
1048 | ||
1049 | /* Someone calling slave DMA on a generic channel? */ | |
1050 | if (rchan->mid_rid < 0 || buf_len < period_len) { | |
1051 | dev_warn(chan->device->dev, | |
1052 | "%s: bad parameter: buf_len=%zu, period_len=%zu, id=%d\n", | |
1053 | __func__, buf_len, period_len, rchan->mid_rid); | |
1054 | return NULL; | |
1055 | } | |
1056 | ||
1057 | sg_len = buf_len / period_len; | |
1058 | if (sg_len > RCAR_DMAC_MAX_SG_LEN) { | |
1059 | dev_err(chan->device->dev, | |
1060 | "chan%u: sg length %d exceds limit %d", | |
1061 | rchan->index, sg_len, RCAR_DMAC_MAX_SG_LEN); | |
1062 | return NULL; | |
1063 | } | |
1064 | ||
1065 | /* | |
1066 | * Allocate the sg list dynamically as it would consume too much stack | |
1067 | * space. | |
1068 | */ | |
1069 | sgl = kcalloc(sg_len, sizeof(*sgl), GFP_NOWAIT); | |
1070 | if (!sgl) | |
1071 | return NULL; | |
1072 | ||
1073 | sg_init_table(sgl, sg_len); | |
1074 | ||
1075 | for (i = 0; i < sg_len; ++i) { | |
1076 | dma_addr_t src = buf_addr + (period_len * i); | |
1077 | ||
1078 | sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len, | |
1079 | offset_in_page(src)); | |
1080 | sg_dma_address(&sgl[i]) = src; | |
1081 | sg_dma_len(&sgl[i]) = period_len; | |
1082 | } | |
1083 | ||
1084 | dev_addr = dir == DMA_DEV_TO_MEM | |
1085 | ? rchan->src_slave_addr : rchan->dst_slave_addr; | |
1086 | desc = rcar_dmac_chan_prep_sg(rchan, sgl, sg_len, dev_addr, | |
1087 | dir, flags, true); | |
1088 | ||
1089 | kfree(sgl); | |
1090 | return desc; | |
1091 | } | |
1092 | ||
1093 | static int rcar_dmac_device_config(struct dma_chan *chan, | |
1094 | struct dma_slave_config *cfg) | |
1095 | { | |
1096 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
1097 | ||
1098 | /* | |
1099 | * We could lock this, but you shouldn't be configuring the | |
1100 | * channel, while using it... | |
1101 | */ | |
1102 | rchan->src_slave_addr = cfg->src_addr; | |
1103 | rchan->dst_slave_addr = cfg->dst_addr; | |
1104 | rchan->src_xfer_size = cfg->src_addr_width; | |
1105 | rchan->dst_xfer_size = cfg->dst_addr_width; | |
1106 | ||
1107 | return 0; | |
1108 | } | |
1109 | ||
1110 | static int rcar_dmac_chan_terminate_all(struct dma_chan *chan) | |
1111 | { | |
1112 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
1113 | unsigned long flags; | |
1114 | ||
1115 | spin_lock_irqsave(&rchan->lock, flags); | |
1116 | rcar_dmac_chan_halt(rchan); | |
1117 | spin_unlock_irqrestore(&rchan->lock, flags); | |
1118 | ||
1119 | /* | |
1120 | * FIXME: No new interrupt can occur now, but the IRQ thread might still | |
1121 | * be running. | |
1122 | */ | |
1123 | ||
1124 | rcar_dmac_chan_reinit(rchan); | |
1125 | ||
1126 | return 0; | |
1127 | } | |
1128 | ||
1129 | static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan, | |
1130 | dma_cookie_t cookie) | |
1131 | { | |
1132 | struct rcar_dmac_desc *desc = chan->desc.running; | |
ccadee9b | 1133 | struct rcar_dmac_xfer_chunk *running = NULL; |
87244fe5 LP |
1134 | struct rcar_dmac_xfer_chunk *chunk; |
1135 | unsigned int residue = 0; | |
ccadee9b | 1136 | unsigned int dptr = 0; |
87244fe5 LP |
1137 | |
1138 | if (!desc) | |
1139 | return 0; | |
1140 | ||
1141 | /* | |
1142 | * If the cookie doesn't correspond to the currently running transfer | |
1143 | * then the descriptor hasn't been processed yet, and the residue is | |
1144 | * equal to the full descriptor size. | |
1145 | */ | |
1146 | if (cookie != desc->async_tx.cookie) | |
1147 | return desc->size; | |
1148 | ||
ccadee9b LP |
1149 | /* |
1150 | * In descriptor mode the descriptor running pointer is not maintained | |
1151 | * by the interrupt handler, find the running descriptor from the | |
1152 | * descriptor pointer field in the CHCRB register. In non-descriptor | |
1153 | * mode just use the running descriptor pointer. | |
1154 | */ | |
1ed1315f | 1155 | if (desc->hwdescs.use) { |
ccadee9b LP |
1156 | dptr = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & |
1157 | RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT; | |
1158 | WARN_ON(dptr >= desc->nchunks); | |
1159 | } else { | |
1160 | running = desc->running; | |
1161 | } | |
1162 | ||
87244fe5 LP |
1163 | /* Compute the size of all chunks still to be transferred. */ |
1164 | list_for_each_entry_reverse(chunk, &desc->chunks, node) { | |
ccadee9b | 1165 | if (chunk == running || ++dptr == desc->nchunks) |
87244fe5 LP |
1166 | break; |
1167 | ||
1168 | residue += chunk->size; | |
1169 | } | |
1170 | ||
1171 | /* Add the residue for the current chunk. */ | |
1172 | residue += rcar_dmac_chan_read(chan, RCAR_DMATCR) << desc->xfer_shift; | |
1173 | ||
1174 | return residue; | |
1175 | } | |
1176 | ||
1177 | static enum dma_status rcar_dmac_tx_status(struct dma_chan *chan, | |
1178 | dma_cookie_t cookie, | |
1179 | struct dma_tx_state *txstate) | |
1180 | { | |
1181 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
1182 | enum dma_status status; | |
1183 | unsigned long flags; | |
1184 | unsigned int residue; | |
1185 | ||
1186 | status = dma_cookie_status(chan, cookie, txstate); | |
1187 | if (status == DMA_COMPLETE || !txstate) | |
1188 | return status; | |
1189 | ||
1190 | spin_lock_irqsave(&rchan->lock, flags); | |
1191 | residue = rcar_dmac_chan_get_residue(rchan, cookie); | |
1192 | spin_unlock_irqrestore(&rchan->lock, flags); | |
1193 | ||
1194 | dma_set_residue(txstate, residue); | |
1195 | ||
1196 | return status; | |
1197 | } | |
1198 | ||
1199 | static void rcar_dmac_issue_pending(struct dma_chan *chan) | |
1200 | { | |
1201 | struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); | |
1202 | unsigned long flags; | |
1203 | ||
1204 | spin_lock_irqsave(&rchan->lock, flags); | |
1205 | ||
1206 | if (list_empty(&rchan->desc.pending)) | |
1207 | goto done; | |
1208 | ||
1209 | /* Append the pending list to the active list. */ | |
1210 | list_splice_tail_init(&rchan->desc.pending, &rchan->desc.active); | |
1211 | ||
1212 | /* | |
1213 | * If no transfer is running pick the first descriptor from the active | |
1214 | * list and start the transfer. | |
1215 | */ | |
1216 | if (!rchan->desc.running) { | |
1217 | struct rcar_dmac_desc *desc; | |
1218 | ||
1219 | desc = list_first_entry(&rchan->desc.active, | |
1220 | struct rcar_dmac_desc, node); | |
1221 | rchan->desc.running = desc; | |
1222 | ||
1223 | rcar_dmac_chan_start_xfer(rchan); | |
1224 | } | |
1225 | ||
1226 | done: | |
1227 | spin_unlock_irqrestore(&rchan->lock, flags); | |
1228 | } | |
1229 | ||
1230 | /* ----------------------------------------------------------------------------- | |
1231 | * IRQ handling | |
1232 | */ | |
1233 | ||
ccadee9b LP |
1234 | static irqreturn_t rcar_dmac_isr_desc_stage_end(struct rcar_dmac_chan *chan) |
1235 | { | |
1236 | struct rcar_dmac_desc *desc = chan->desc.running; | |
1237 | unsigned int stage; | |
1238 | ||
1239 | if (WARN_ON(!desc || !desc->cyclic)) { | |
1240 | /* | |
1241 | * This should never happen, there should always be a running | |
1242 | * cyclic descriptor when a descriptor stage end interrupt is | |
1243 | * triggered. Warn and return. | |
1244 | */ | |
1245 | return IRQ_NONE; | |
1246 | } | |
1247 | ||
1248 | /* Program the interrupt pointer to the next stage. */ | |
1249 | stage = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & | |
1250 | RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT; | |
1251 | rcar_dmac_chan_write(chan, RCAR_DMADPCR, RCAR_DMADPCR_DIPT(stage)); | |
1252 | ||
1253 | return IRQ_WAKE_THREAD; | |
1254 | } | |
1255 | ||
87244fe5 LP |
1256 | static irqreturn_t rcar_dmac_isr_transfer_end(struct rcar_dmac_chan *chan) |
1257 | { | |
1258 | struct rcar_dmac_desc *desc = chan->desc.running; | |
87244fe5 LP |
1259 | irqreturn_t ret = IRQ_WAKE_THREAD; |
1260 | ||
1261 | if (WARN_ON_ONCE(!desc)) { | |
1262 | /* | |
ccadee9b LP |
1263 | * This should never happen, there should always be a running |
1264 | * descriptor when a transfer end interrupt is triggered. Warn | |
1265 | * and return. | |
87244fe5 LP |
1266 | */ |
1267 | return IRQ_NONE; | |
1268 | } | |
1269 | ||
1270 | /* | |
ccadee9b LP |
1271 | * The transfer end interrupt isn't generated for each chunk when using |
1272 | * descriptor mode. Only update the running chunk pointer in | |
1273 | * non-descriptor mode. | |
87244fe5 | 1274 | */ |
1ed1315f | 1275 | if (!desc->hwdescs.use) { |
ccadee9b LP |
1276 | /* |
1277 | * If we haven't completed the last transfer chunk simply move | |
1278 | * to the next one. Only wake the IRQ thread if the transfer is | |
1279 | * cyclic. | |
1280 | */ | |
1281 | if (!list_is_last(&desc->running->node, &desc->chunks)) { | |
1282 | desc->running = list_next_entry(desc->running, node); | |
1283 | if (!desc->cyclic) | |
1284 | ret = IRQ_HANDLED; | |
1285 | goto done; | |
1286 | } | |
87244fe5 | 1287 | |
ccadee9b LP |
1288 | /* |
1289 | * We've completed the last transfer chunk. If the transfer is | |
1290 | * cyclic, move back to the first one. | |
1291 | */ | |
1292 | if (desc->cyclic) { | |
1293 | desc->running = | |
1294 | list_first_entry(&desc->chunks, | |
87244fe5 LP |
1295 | struct rcar_dmac_xfer_chunk, |
1296 | node); | |
ccadee9b LP |
1297 | goto done; |
1298 | } | |
87244fe5 LP |
1299 | } |
1300 | ||
1301 | /* The descriptor is complete, move it to the done list. */ | |
1302 | list_move_tail(&desc->node, &chan->desc.done); | |
1303 | ||
1304 | /* Queue the next descriptor, if any. */ | |
1305 | if (!list_empty(&chan->desc.active)) | |
1306 | chan->desc.running = list_first_entry(&chan->desc.active, | |
1307 | struct rcar_dmac_desc, | |
1308 | node); | |
1309 | else | |
1310 | chan->desc.running = NULL; | |
1311 | ||
1312 | done: | |
1313 | if (chan->desc.running) | |
1314 | rcar_dmac_chan_start_xfer(chan); | |
1315 | ||
1316 | return ret; | |
1317 | } | |
1318 | ||
1319 | static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev) | |
1320 | { | |
ccadee9b | 1321 | u32 mask = RCAR_DMACHCR_DSE | RCAR_DMACHCR_TE; |
87244fe5 LP |
1322 | struct rcar_dmac_chan *chan = dev; |
1323 | irqreturn_t ret = IRQ_NONE; | |
1324 | u32 chcr; | |
1325 | ||
1326 | spin_lock(&chan->lock); | |
1327 | ||
1328 | chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); | |
ccadee9b LP |
1329 | if (chcr & RCAR_DMACHCR_TE) |
1330 | mask |= RCAR_DMACHCR_DE; | |
1331 | rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask); | |
1332 | ||
1333 | if (chcr & RCAR_DMACHCR_DSE) | |
1334 | ret |= rcar_dmac_isr_desc_stage_end(chan); | |
87244fe5 LP |
1335 | |
1336 | if (chcr & RCAR_DMACHCR_TE) | |
1337 | ret |= rcar_dmac_isr_transfer_end(chan); | |
1338 | ||
1339 | spin_unlock(&chan->lock); | |
1340 | ||
1341 | return ret; | |
1342 | } | |
1343 | ||
1344 | static irqreturn_t rcar_dmac_isr_channel_thread(int irq, void *dev) | |
1345 | { | |
1346 | struct rcar_dmac_chan *chan = dev; | |
1347 | struct rcar_dmac_desc *desc; | |
1348 | ||
1349 | spin_lock_irq(&chan->lock); | |
1350 | ||
1351 | /* For cyclic transfers notify the user after every chunk. */ | |
1352 | if (chan->desc.running && chan->desc.running->cyclic) { | |
1353 | dma_async_tx_callback callback; | |
1354 | void *callback_param; | |
1355 | ||
1356 | desc = chan->desc.running; | |
1357 | callback = desc->async_tx.callback; | |
1358 | callback_param = desc->async_tx.callback_param; | |
1359 | ||
1360 | if (callback) { | |
1361 | spin_unlock_irq(&chan->lock); | |
1362 | callback(callback_param); | |
1363 | spin_lock_irq(&chan->lock); | |
1364 | } | |
1365 | } | |
1366 | ||
1367 | /* | |
1368 | * Call the callback function for all descriptors on the done list and | |
1369 | * move them to the ack wait list. | |
1370 | */ | |
1371 | while (!list_empty(&chan->desc.done)) { | |
1372 | desc = list_first_entry(&chan->desc.done, struct rcar_dmac_desc, | |
1373 | node); | |
1374 | dma_cookie_complete(&desc->async_tx); | |
1375 | list_del(&desc->node); | |
1376 | ||
1377 | if (desc->async_tx.callback) { | |
1378 | spin_unlock_irq(&chan->lock); | |
1379 | /* | |
1380 | * We own the only reference to this descriptor, we can | |
1381 | * safely dereference it without holding the channel | |
1382 | * lock. | |
1383 | */ | |
1384 | desc->async_tx.callback(desc->async_tx.callback_param); | |
1385 | spin_lock_irq(&chan->lock); | |
1386 | } | |
1387 | ||
1388 | list_add_tail(&desc->node, &chan->desc.wait); | |
1389 | } | |
1390 | ||
ccadee9b LP |
1391 | spin_unlock_irq(&chan->lock); |
1392 | ||
87244fe5 LP |
1393 | /* Recycle all acked descriptors. */ |
1394 | rcar_dmac_desc_recycle_acked(chan); | |
1395 | ||
87244fe5 LP |
1396 | return IRQ_HANDLED; |
1397 | } | |
1398 | ||
1399 | static irqreturn_t rcar_dmac_isr_error(int irq, void *data) | |
1400 | { | |
1401 | struct rcar_dmac *dmac = data; | |
1402 | ||
1403 | if (!(rcar_dmac_read(dmac, RCAR_DMAOR) & RCAR_DMAOR_AE)) | |
1404 | return IRQ_NONE; | |
1405 | ||
1406 | /* | |
1407 | * An unrecoverable error occurred on an unknown channel. Halt the DMAC, | |
1408 | * abort transfers on all channels, and reinitialize the DMAC. | |
1409 | */ | |
1410 | rcar_dmac_stop(dmac); | |
1411 | rcar_dmac_abort(dmac); | |
1412 | rcar_dmac_init(dmac); | |
1413 | ||
1414 | return IRQ_HANDLED; | |
1415 | } | |
1416 | ||
1417 | /* ----------------------------------------------------------------------------- | |
1418 | * OF xlate and channel filter | |
1419 | */ | |
1420 | ||
1421 | static bool rcar_dmac_chan_filter(struct dma_chan *chan, void *arg) | |
1422 | { | |
1423 | struct rcar_dmac *dmac = to_rcar_dmac(chan->device); | |
1424 | struct of_phandle_args *dma_spec = arg; | |
1425 | ||
1426 | /* | |
1427 | * FIXME: Using a filter on OF platforms is a nonsense. The OF xlate | |
1428 | * function knows from which device it wants to allocate a channel from, | |
1429 | * and would be perfectly capable of selecting the channel it wants. | |
1430 | * Forcing it to call dma_request_channel() and iterate through all | |
1431 | * channels from all controllers is just pointless. | |
1432 | */ | |
1433 | if (chan->device->device_config != rcar_dmac_device_config || | |
1434 | dma_spec->np != chan->device->dev->of_node) | |
1435 | return false; | |
1436 | ||
1437 | return !test_and_set_bit(dma_spec->args[0], dmac->modules); | |
1438 | } | |
1439 | ||
1440 | static struct dma_chan *rcar_dmac_of_xlate(struct of_phandle_args *dma_spec, | |
1441 | struct of_dma *ofdma) | |
1442 | { | |
1443 | struct rcar_dmac_chan *rchan; | |
1444 | struct dma_chan *chan; | |
1445 | dma_cap_mask_t mask; | |
1446 | ||
1447 | if (dma_spec->args_count != 1) | |
1448 | return NULL; | |
1449 | ||
1450 | /* Only slave DMA channels can be allocated via DT */ | |
1451 | dma_cap_zero(mask); | |
1452 | dma_cap_set(DMA_SLAVE, mask); | |
1453 | ||
1454 | chan = dma_request_channel(mask, rcar_dmac_chan_filter, dma_spec); | |
1455 | if (!chan) | |
1456 | return NULL; | |
1457 | ||
1458 | rchan = to_rcar_dmac_chan(chan); | |
1459 | rchan->mid_rid = dma_spec->args[0]; | |
1460 | ||
1461 | return chan; | |
1462 | } | |
1463 | ||
1464 | /* ----------------------------------------------------------------------------- | |
1465 | * Power management | |
1466 | */ | |
1467 | ||
1468 | #ifdef CONFIG_PM_SLEEP | |
1469 | static int rcar_dmac_sleep_suspend(struct device *dev) | |
1470 | { | |
1471 | /* | |
1472 | * TODO: Wait for the current transfer to complete and stop the device. | |
1473 | */ | |
1474 | return 0; | |
1475 | } | |
1476 | ||
1477 | static int rcar_dmac_sleep_resume(struct device *dev) | |
1478 | { | |
1479 | /* TODO: Resume transfers, if any. */ | |
1480 | return 0; | |
1481 | } | |
1482 | #endif | |
1483 | ||
1484 | #ifdef CONFIG_PM | |
1485 | static int rcar_dmac_runtime_suspend(struct device *dev) | |
1486 | { | |
1487 | return 0; | |
1488 | } | |
1489 | ||
1490 | static int rcar_dmac_runtime_resume(struct device *dev) | |
1491 | { | |
1492 | struct rcar_dmac *dmac = dev_get_drvdata(dev); | |
1493 | ||
1494 | return rcar_dmac_init(dmac); | |
1495 | } | |
1496 | #endif | |
1497 | ||
1498 | static const struct dev_pm_ops rcar_dmac_pm = { | |
1499 | SET_SYSTEM_SLEEP_PM_OPS(rcar_dmac_sleep_suspend, rcar_dmac_sleep_resume) | |
1500 | SET_RUNTIME_PM_OPS(rcar_dmac_runtime_suspend, rcar_dmac_runtime_resume, | |
1501 | NULL) | |
1502 | }; | |
1503 | ||
1504 | /* ----------------------------------------------------------------------------- | |
1505 | * Probe and remove | |
1506 | */ | |
1507 | ||
1508 | static int rcar_dmac_chan_probe(struct rcar_dmac *dmac, | |
1509 | struct rcar_dmac_chan *rchan, | |
1510 | unsigned int index) | |
1511 | { | |
1512 | struct platform_device *pdev = to_platform_device(dmac->dev); | |
1513 | struct dma_chan *chan = &rchan->chan; | |
1514 | char pdev_irqname[5]; | |
1515 | char *irqname; | |
1516 | int irq; | |
1517 | int ret; | |
1518 | ||
1519 | rchan->index = index; | |
1520 | rchan->iomem = dmac->iomem + RCAR_DMAC_CHAN_OFFSET(index); | |
1521 | rchan->mid_rid = -EINVAL; | |
1522 | ||
1523 | spin_lock_init(&rchan->lock); | |
1524 | ||
1525 | /* Request the channel interrupt. */ | |
1526 | sprintf(pdev_irqname, "ch%u", index); | |
1527 | irq = platform_get_irq_byname(pdev, pdev_irqname); | |
1528 | if (irq < 0) { | |
1529 | dev_err(dmac->dev, "no IRQ specified for channel %u\n", index); | |
1530 | return -ENODEV; | |
1531 | } | |
1532 | ||
1533 | irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:%u", | |
1534 | dev_name(dmac->dev), index); | |
1535 | if (!irqname) | |
1536 | return -ENOMEM; | |
1537 | ||
1538 | ret = devm_request_threaded_irq(dmac->dev, irq, rcar_dmac_isr_channel, | |
1539 | rcar_dmac_isr_channel_thread, 0, | |
1540 | irqname, rchan); | |
1541 | if (ret) { | |
1542 | dev_err(dmac->dev, "failed to request IRQ %u (%d)\n", irq, ret); | |
1543 | return ret; | |
1544 | } | |
1545 | ||
1546 | /* | |
1547 | * Initialize the DMA engine channel and add it to the DMA engine | |
1548 | * channels list. | |
1549 | */ | |
1550 | chan->device = &dmac->engine; | |
1551 | dma_cookie_init(chan); | |
1552 | ||
1553 | list_add_tail(&chan->device_node, &dmac->engine.channels); | |
1554 | ||
1555 | return 0; | |
1556 | } | |
1557 | ||
1558 | static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac) | |
1559 | { | |
1560 | struct device_node *np = dev->of_node; | |
1561 | int ret; | |
1562 | ||
1563 | ret = of_property_read_u32(np, "dma-channels", &dmac->n_channels); | |
1564 | if (ret < 0) { | |
1565 | dev_err(dev, "unable to read dma-channels property\n"); | |
1566 | return ret; | |
1567 | } | |
1568 | ||
1569 | if (dmac->n_channels <= 0 || dmac->n_channels >= 100) { | |
1570 | dev_err(dev, "invalid number of channels %u\n", | |
1571 | dmac->n_channels); | |
1572 | return -EINVAL; | |
1573 | } | |
1574 | ||
1575 | return 0; | |
1576 | } | |
1577 | ||
1578 | static int rcar_dmac_probe(struct platform_device *pdev) | |
1579 | { | |
1580 | const enum dma_slave_buswidth widths = DMA_SLAVE_BUSWIDTH_1_BYTE | | |
1581 | DMA_SLAVE_BUSWIDTH_2_BYTES | DMA_SLAVE_BUSWIDTH_4_BYTES | | |
1582 | DMA_SLAVE_BUSWIDTH_8_BYTES | DMA_SLAVE_BUSWIDTH_16_BYTES | | |
1583 | DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES; | |
1584 | struct dma_device *engine; | |
1585 | struct rcar_dmac *dmac; | |
1586 | struct resource *mem; | |
1587 | unsigned int i; | |
1588 | char *irqname; | |
1589 | int irq; | |
1590 | int ret; | |
1591 | ||
1592 | dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL); | |
1593 | if (!dmac) | |
1594 | return -ENOMEM; | |
1595 | ||
1596 | dmac->dev = &pdev->dev; | |
1597 | platform_set_drvdata(pdev, dmac); | |
1598 | ||
1599 | ret = rcar_dmac_parse_of(&pdev->dev, dmac); | |
1600 | if (ret < 0) | |
1601 | return ret; | |
1602 | ||
1603 | dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, | |
1604 | sizeof(*dmac->channels), GFP_KERNEL); | |
1605 | if (!dmac->channels) | |
1606 | return -ENOMEM; | |
1607 | ||
1608 | /* Request resources. */ | |
1609 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
1610 | dmac->iomem = devm_ioremap_resource(&pdev->dev, mem); | |
1611 | if (IS_ERR(dmac->iomem)) | |
1612 | return PTR_ERR(dmac->iomem); | |
1613 | ||
1614 | irq = platform_get_irq_byname(pdev, "error"); | |
1615 | if (irq < 0) { | |
1616 | dev_err(&pdev->dev, "no error IRQ specified\n"); | |
1617 | return -ENODEV; | |
1618 | } | |
1619 | ||
1620 | irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:error", | |
1621 | dev_name(dmac->dev)); | |
1622 | if (!irqname) | |
1623 | return -ENOMEM; | |
1624 | ||
1625 | ret = devm_request_irq(&pdev->dev, irq, rcar_dmac_isr_error, 0, | |
1626 | irqname, dmac); | |
1627 | if (ret) { | |
1628 | dev_err(&pdev->dev, "failed to request IRQ %u (%d)\n", | |
1629 | irq, ret); | |
1630 | return ret; | |
1631 | } | |
1632 | ||
1633 | /* Enable runtime PM and initialize the device. */ | |
1634 | pm_runtime_enable(&pdev->dev); | |
1635 | ret = pm_runtime_get_sync(&pdev->dev); | |
1636 | if (ret < 0) { | |
1637 | dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret); | |
1638 | return ret; | |
1639 | } | |
1640 | ||
1641 | ret = rcar_dmac_init(dmac); | |
1642 | pm_runtime_put(&pdev->dev); | |
1643 | ||
1644 | if (ret) { | |
1645 | dev_err(&pdev->dev, "failed to reset device\n"); | |
1646 | goto error; | |
1647 | } | |
1648 | ||
1649 | /* Initialize the channels. */ | |
1650 | INIT_LIST_HEAD(&dmac->engine.channels); | |
1651 | ||
1652 | for (i = 0; i < dmac->n_channels; ++i) { | |
1653 | ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], i); | |
1654 | if (ret < 0) | |
1655 | goto error; | |
1656 | } | |
1657 | ||
1658 | /* Register the DMAC as a DMA provider for DT. */ | |
1659 | ret = of_dma_controller_register(pdev->dev.of_node, rcar_dmac_of_xlate, | |
1660 | NULL); | |
1661 | if (ret < 0) | |
1662 | goto error; | |
1663 | ||
1664 | /* | |
1665 | * Register the DMA engine device. | |
1666 | * | |
1667 | * Default transfer size of 32 bytes requires 32-byte alignment. | |
1668 | */ | |
1669 | engine = &dmac->engine; | |
1670 | dma_cap_set(DMA_MEMCPY, engine->cap_mask); | |
1671 | dma_cap_set(DMA_SLAVE, engine->cap_mask); | |
1672 | ||
1673 | engine->dev = &pdev->dev; | |
1674 | engine->copy_align = ilog2(RCAR_DMAC_MEMCPY_XFER_SIZE); | |
1675 | ||
1676 | engine->src_addr_widths = widths; | |
1677 | engine->dst_addr_widths = widths; | |
1678 | engine->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); | |
1679 | engine->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; | |
1680 | ||
1681 | engine->device_alloc_chan_resources = rcar_dmac_alloc_chan_resources; | |
1682 | engine->device_free_chan_resources = rcar_dmac_free_chan_resources; | |
1683 | engine->device_prep_dma_memcpy = rcar_dmac_prep_dma_memcpy; | |
1684 | engine->device_prep_slave_sg = rcar_dmac_prep_slave_sg; | |
1685 | engine->device_prep_dma_cyclic = rcar_dmac_prep_dma_cyclic; | |
1686 | engine->device_config = rcar_dmac_device_config; | |
1687 | engine->device_terminate_all = rcar_dmac_chan_terminate_all; | |
1688 | engine->device_tx_status = rcar_dmac_tx_status; | |
1689 | engine->device_issue_pending = rcar_dmac_issue_pending; | |
1690 | ||
1691 | ret = dma_async_device_register(engine); | |
1692 | if (ret < 0) | |
1693 | goto error; | |
1694 | ||
1695 | return 0; | |
1696 | ||
1697 | error: | |
1698 | of_dma_controller_free(pdev->dev.of_node); | |
1699 | pm_runtime_disable(&pdev->dev); | |
1700 | return ret; | |
1701 | } | |
1702 | ||
1703 | static int rcar_dmac_remove(struct platform_device *pdev) | |
1704 | { | |
1705 | struct rcar_dmac *dmac = platform_get_drvdata(pdev); | |
1706 | ||
1707 | of_dma_controller_free(pdev->dev.of_node); | |
1708 | dma_async_device_unregister(&dmac->engine); | |
1709 | ||
1710 | pm_runtime_disable(&pdev->dev); | |
1711 | ||
1712 | return 0; | |
1713 | } | |
1714 | ||
1715 | static void rcar_dmac_shutdown(struct platform_device *pdev) | |
1716 | { | |
1717 | struct rcar_dmac *dmac = platform_get_drvdata(pdev); | |
1718 | ||
1719 | rcar_dmac_stop(dmac); | |
1720 | } | |
1721 | ||
1722 | static const struct of_device_id rcar_dmac_of_ids[] = { | |
1723 | { .compatible = "renesas,rcar-dmac", }, | |
1724 | { /* Sentinel */ } | |
1725 | }; | |
1726 | MODULE_DEVICE_TABLE(of, rcar_dmac_of_ids); | |
1727 | ||
1728 | static struct platform_driver rcar_dmac_driver = { | |
1729 | .driver = { | |
1730 | .pm = &rcar_dmac_pm, | |
1731 | .name = "rcar-dmac", | |
1732 | .of_match_table = rcar_dmac_of_ids, | |
1733 | }, | |
1734 | .probe = rcar_dmac_probe, | |
1735 | .remove = rcar_dmac_remove, | |
1736 | .shutdown = rcar_dmac_shutdown, | |
1737 | }; | |
1738 | ||
1739 | module_platform_driver(rcar_dmac_driver); | |
1740 | ||
1741 | MODULE_DESCRIPTION("R-Car Gen2 DMA Controller Driver"); | |
1742 | MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); | |
1743 | MODULE_LICENSE("GPL v2"); |