Commit | Line | Data |
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2b49e0c5 AS |
1 | /* |
2 | * Core driver for the High Speed UART DMA | |
3 | * | |
4 | * Copyright (C) 2015 Intel Corporation | |
5 | * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> | |
6 | * | |
7 | * Partially based on the bits found in drivers/tty/serial/mfd.c. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | /* | |
15 | * DMA channel allocation: | |
16 | * 1. Even number chans are used for DMA Read (UART TX), odd chans for DMA | |
17 | * Write (UART RX). | |
18 | * 2. 0/1 channel are assigned to port 0, 2/3 chan to port 1, 4/5 chan to | |
19 | * port 3, and so on. | |
20 | */ | |
21 | ||
22 | #include <linux/delay.h> | |
23 | #include <linux/dmaengine.h> | |
24 | #include <linux/dma-mapping.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/slab.h> | |
28 | ||
29 | #include "hsu.h" | |
30 | ||
31 | #define HSU_DMA_BUSWIDTHS \ | |
32 | BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \ | |
33 | BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \ | |
34 | BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \ | |
35 | BIT(DMA_SLAVE_BUSWIDTH_3_BYTES) | \ | |
36 | BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \ | |
37 | BIT(DMA_SLAVE_BUSWIDTH_8_BYTES) | \ | |
38 | BIT(DMA_SLAVE_BUSWIDTH_16_BYTES) | |
39 | ||
40 | static inline void hsu_chan_disable(struct hsu_dma_chan *hsuc) | |
41 | { | |
42 | hsu_chan_writel(hsuc, HSU_CH_CR, 0); | |
43 | } | |
44 | ||
45 | static inline void hsu_chan_enable(struct hsu_dma_chan *hsuc) | |
46 | { | |
47 | u32 cr = HSU_CH_CR_CHA; | |
48 | ||
49 | if (hsuc->direction == DMA_MEM_TO_DEV) | |
50 | cr &= ~HSU_CH_CR_CHD; | |
51 | else if (hsuc->direction == DMA_DEV_TO_MEM) | |
52 | cr |= HSU_CH_CR_CHD; | |
53 | ||
54 | hsu_chan_writel(hsuc, HSU_CH_CR, cr); | |
55 | } | |
56 | ||
57 | static void hsu_dma_chan_start(struct hsu_dma_chan *hsuc) | |
58 | { | |
59 | struct dma_slave_config *config = &hsuc->config; | |
60 | struct hsu_dma_desc *desc = hsuc->desc; | |
4bb82458 | 61 | u32 bsr = 0, mtsr = 0; /* to shut the compiler up */ |
2b49e0c5 AS |
62 | u32 dcr = HSU_CH_DCR_CHSOE | HSU_CH_DCR_CHEI; |
63 | unsigned int i, count; | |
64 | ||
65 | if (hsuc->direction == DMA_MEM_TO_DEV) { | |
66 | bsr = config->dst_maxburst; | |
080edf75 | 67 | mtsr = config->src_addr_width; |
2b49e0c5 AS |
68 | } else if (hsuc->direction == DMA_DEV_TO_MEM) { |
69 | bsr = config->src_maxburst; | |
080edf75 | 70 | mtsr = config->dst_addr_width; |
2b49e0c5 AS |
71 | } |
72 | ||
73 | hsu_chan_disable(hsuc); | |
74 | ||
75 | hsu_chan_writel(hsuc, HSU_CH_DCR, 0); | |
76 | hsu_chan_writel(hsuc, HSU_CH_BSR, bsr); | |
77 | hsu_chan_writel(hsuc, HSU_CH_MTSR, mtsr); | |
78 | ||
79 | /* Set descriptors */ | |
80 | count = (desc->nents - desc->active) % HSU_DMA_CHAN_NR_DESC; | |
81 | for (i = 0; i < count; i++) { | |
82 | hsu_chan_writel(hsuc, HSU_CH_DxSAR(i), desc->sg[i].addr); | |
83 | hsu_chan_writel(hsuc, HSU_CH_DxTSR(i), desc->sg[i].len); | |
84 | ||
85 | /* Prepare value for DCR */ | |
86 | dcr |= HSU_CH_DCR_DESCA(i); | |
87 | dcr |= HSU_CH_DCR_CHTOI(i); /* timeout bit, see HSU Errata 1 */ | |
88 | ||
89 | desc->active++; | |
90 | } | |
91 | /* Only for the last descriptor in the chain */ | |
92 | dcr |= HSU_CH_DCR_CHSOD(count - 1); | |
93 | dcr |= HSU_CH_DCR_CHDI(count - 1); | |
94 | ||
95 | hsu_chan_writel(hsuc, HSU_CH_DCR, dcr); | |
96 | ||
97 | hsu_chan_enable(hsuc); | |
98 | } | |
99 | ||
100 | static void hsu_dma_stop_channel(struct hsu_dma_chan *hsuc) | |
101 | { | |
2b49e0c5 AS |
102 | hsu_chan_disable(hsuc); |
103 | hsu_chan_writel(hsuc, HSU_CH_DCR, 0); | |
2b49e0c5 AS |
104 | } |
105 | ||
106 | static void hsu_dma_start_channel(struct hsu_dma_chan *hsuc) | |
107 | { | |
2b49e0c5 | 108 | hsu_dma_chan_start(hsuc); |
2b49e0c5 AS |
109 | } |
110 | ||
111 | static void hsu_dma_start_transfer(struct hsu_dma_chan *hsuc) | |
112 | { | |
113 | struct virt_dma_desc *vdesc; | |
114 | ||
115 | /* Get the next descriptor */ | |
116 | vdesc = vchan_next_desc(&hsuc->vchan); | |
117 | if (!vdesc) { | |
118 | hsuc->desc = NULL; | |
119 | return; | |
120 | } | |
121 | ||
122 | list_del(&vdesc->node); | |
123 | hsuc->desc = to_hsu_dma_desc(vdesc); | |
124 | ||
125 | /* Start the channel with a new descriptor */ | |
126 | hsu_dma_start_channel(hsuc); | |
127 | } | |
128 | ||
129 | static u32 hsu_dma_chan_get_sr(struct hsu_dma_chan *hsuc) | |
130 | { | |
131 | unsigned long flags; | |
132 | u32 sr; | |
133 | ||
03734485 | 134 | spin_lock_irqsave(&hsuc->vchan.lock, flags); |
2b49e0c5 | 135 | sr = hsu_chan_readl(hsuc, HSU_CH_SR); |
03734485 | 136 | spin_unlock_irqrestore(&hsuc->vchan.lock, flags); |
2b49e0c5 | 137 | |
4f4bc0ab | 138 | return sr & ~(HSU_CH_SR_DESCE_ANY | HSU_CH_SR_CDESC_ANY); |
2b49e0c5 AS |
139 | } |
140 | ||
141 | irqreturn_t hsu_dma_irq(struct hsu_dma_chip *chip, unsigned short nr) | |
142 | { | |
143 | struct hsu_dma_chan *hsuc; | |
144 | struct hsu_dma_desc *desc; | |
145 | unsigned long flags; | |
146 | u32 sr; | |
147 | ||
148 | /* Sanity check */ | |
4c97ad99 | 149 | if (nr >= chip->hsu->nr_channels) |
2b49e0c5 AS |
150 | return IRQ_NONE; |
151 | ||
152 | hsuc = &chip->hsu->chan[nr]; | |
153 | ||
154 | /* | |
155 | * No matter what situation, need read clear the IRQ status | |
156 | * There is a bug, see Errata 5, HSD 2900918 | |
157 | */ | |
158 | sr = hsu_dma_chan_get_sr(hsuc); | |
159 | if (!sr) | |
160 | return IRQ_NONE; | |
161 | ||
162 | /* Timeout IRQ, need wait some time, see Errata 2 */ | |
163 | if (hsuc->direction == DMA_DEV_TO_MEM && (sr & HSU_CH_SR_DESCTO_ANY)) | |
164 | udelay(2); | |
165 | ||
166 | sr &= ~HSU_CH_SR_DESCTO_ANY; | |
167 | if (!sr) | |
168 | return IRQ_HANDLED; | |
169 | ||
170 | spin_lock_irqsave(&hsuc->vchan.lock, flags); | |
171 | desc = hsuc->desc; | |
172 | if (desc) { | |
173 | if (sr & HSU_CH_SR_CHE) { | |
174 | desc->status = DMA_ERROR; | |
175 | } else if (desc->active < desc->nents) { | |
176 | hsu_dma_start_channel(hsuc); | |
177 | } else { | |
178 | vchan_cookie_complete(&desc->vdesc); | |
179 | desc->status = DMA_COMPLETE; | |
180 | hsu_dma_start_transfer(hsuc); | |
181 | } | |
182 | } | |
183 | spin_unlock_irqrestore(&hsuc->vchan.lock, flags); | |
184 | ||
185 | return IRQ_HANDLED; | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(hsu_dma_irq); | |
188 | ||
189 | static struct hsu_dma_desc *hsu_dma_alloc_desc(unsigned int nents) | |
190 | { | |
191 | struct hsu_dma_desc *desc; | |
192 | ||
ad53b26c | 193 | desc = kzalloc(sizeof(*desc), GFP_NOWAIT); |
2b49e0c5 AS |
194 | if (!desc) |
195 | return NULL; | |
196 | ||
ad53b26c | 197 | desc->sg = kcalloc(nents, sizeof(*desc->sg), GFP_NOWAIT); |
2b49e0c5 AS |
198 | if (!desc->sg) { |
199 | kfree(desc); | |
200 | return NULL; | |
201 | } | |
202 | ||
203 | return desc; | |
204 | } | |
205 | ||
206 | static void hsu_dma_desc_free(struct virt_dma_desc *vdesc) | |
207 | { | |
208 | struct hsu_dma_desc *desc = to_hsu_dma_desc(vdesc); | |
209 | ||
210 | kfree(desc->sg); | |
211 | kfree(desc); | |
212 | } | |
213 | ||
214 | static struct dma_async_tx_descriptor *hsu_dma_prep_slave_sg( | |
215 | struct dma_chan *chan, struct scatterlist *sgl, | |
216 | unsigned int sg_len, enum dma_transfer_direction direction, | |
217 | unsigned long flags, void *context) | |
218 | { | |
219 | struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); | |
220 | struct hsu_dma_desc *desc; | |
221 | struct scatterlist *sg; | |
222 | unsigned int i; | |
223 | ||
224 | desc = hsu_dma_alloc_desc(sg_len); | |
225 | if (!desc) | |
226 | return NULL; | |
227 | ||
228 | for_each_sg(sgl, sg, sg_len, i) { | |
229 | desc->sg[i].addr = sg_dma_address(sg); | |
230 | desc->sg[i].len = sg_dma_len(sg); | |
f0579c8c AS |
231 | |
232 | desc->length += sg_dma_len(sg); | |
2b49e0c5 AS |
233 | } |
234 | ||
235 | desc->nents = sg_len; | |
236 | desc->direction = direction; | |
4bb82458 | 237 | /* desc->active = 0 by kzalloc */ |
2b49e0c5 AS |
238 | desc->status = DMA_IN_PROGRESS; |
239 | ||
240 | return vchan_tx_prep(&hsuc->vchan, &desc->vdesc, flags); | |
241 | } | |
242 | ||
243 | static void hsu_dma_issue_pending(struct dma_chan *chan) | |
244 | { | |
245 | struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); | |
246 | unsigned long flags; | |
247 | ||
248 | spin_lock_irqsave(&hsuc->vchan.lock, flags); | |
249 | if (vchan_issue_pending(&hsuc->vchan) && !hsuc->desc) | |
250 | hsu_dma_start_transfer(hsuc); | |
251 | spin_unlock_irqrestore(&hsuc->vchan.lock, flags); | |
252 | } | |
253 | ||
2b49e0c5 AS |
254 | static size_t hsu_dma_active_desc_size(struct hsu_dma_chan *hsuc) |
255 | { | |
256 | struct hsu_dma_desc *desc = hsuc->desc; | |
a197f3c7 | 257 | size_t bytes = 0; |
2b49e0c5 | 258 | int i; |
2b49e0c5 | 259 | |
a197f3c7 AS |
260 | for (i = desc->active; i < desc->nents; i++) |
261 | bytes += desc->sg[i].len; | |
262 | ||
263 | i = HSU_DMA_CHAN_NR_DESC - 1; | |
2b49e0c5 AS |
264 | do { |
265 | bytes += hsu_chan_readl(hsuc, HSU_CH_DxTSR(i)); | |
266 | } while (--i >= 0); | |
2b49e0c5 AS |
267 | |
268 | return bytes; | |
269 | } | |
270 | ||
271 | static enum dma_status hsu_dma_tx_status(struct dma_chan *chan, | |
272 | dma_cookie_t cookie, struct dma_tx_state *state) | |
273 | { | |
274 | struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); | |
275 | struct virt_dma_desc *vdesc; | |
276 | enum dma_status status; | |
277 | size_t bytes; | |
278 | unsigned long flags; | |
279 | ||
280 | status = dma_cookie_status(chan, cookie, state); | |
281 | if (status == DMA_COMPLETE) | |
282 | return status; | |
283 | ||
284 | spin_lock_irqsave(&hsuc->vchan.lock, flags); | |
285 | vdesc = vchan_find_desc(&hsuc->vchan, cookie); | |
286 | if (hsuc->desc && cookie == hsuc->desc->vdesc.tx.cookie) { | |
287 | bytes = hsu_dma_active_desc_size(hsuc); | |
288 | dma_set_residue(state, bytes); | |
289 | status = hsuc->desc->status; | |
290 | } else if (vdesc) { | |
f0579c8c | 291 | bytes = to_hsu_dma_desc(vdesc)->length; |
2b49e0c5 AS |
292 | dma_set_residue(state, bytes); |
293 | } | |
294 | spin_unlock_irqrestore(&hsuc->vchan.lock, flags); | |
295 | ||
296 | return status; | |
297 | } | |
298 | ||
299 | static int hsu_dma_slave_config(struct dma_chan *chan, | |
300 | struct dma_slave_config *config) | |
301 | { | |
302 | struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); | |
303 | ||
304 | /* Check if chan will be configured for slave transfers */ | |
305 | if (!is_slave_direction(config->direction)) | |
306 | return -EINVAL; | |
307 | ||
308 | memcpy(&hsuc->config, config, sizeof(hsuc->config)); | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
2b49e0c5 AS |
313 | static int hsu_dma_pause(struct dma_chan *chan) |
314 | { | |
315 | struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); | |
316 | unsigned long flags; | |
317 | ||
318 | spin_lock_irqsave(&hsuc->vchan.lock, flags); | |
319 | if (hsuc->desc && hsuc->desc->status == DMA_IN_PROGRESS) { | |
03734485 | 320 | hsu_chan_disable(hsuc); |
2b49e0c5 AS |
321 | hsuc->desc->status = DMA_PAUSED; |
322 | } | |
323 | spin_unlock_irqrestore(&hsuc->vchan.lock, flags); | |
324 | ||
325 | return 0; | |
326 | } | |
327 | ||
328 | static int hsu_dma_resume(struct dma_chan *chan) | |
329 | { | |
330 | struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); | |
331 | unsigned long flags; | |
332 | ||
333 | spin_lock_irqsave(&hsuc->vchan.lock, flags); | |
334 | if (hsuc->desc && hsuc->desc->status == DMA_PAUSED) { | |
335 | hsuc->desc->status = DMA_IN_PROGRESS; | |
03734485 | 336 | hsu_chan_enable(hsuc); |
2b49e0c5 AS |
337 | } |
338 | spin_unlock_irqrestore(&hsuc->vchan.lock, flags); | |
339 | ||
340 | return 0; | |
341 | } | |
342 | ||
343 | static int hsu_dma_terminate_all(struct dma_chan *chan) | |
344 | { | |
345 | struct hsu_dma_chan *hsuc = to_hsu_dma_chan(chan); | |
346 | unsigned long flags; | |
347 | LIST_HEAD(head); | |
348 | ||
349 | spin_lock_irqsave(&hsuc->vchan.lock, flags); | |
350 | ||
351 | hsu_dma_stop_channel(hsuc); | |
42977082 PU |
352 | if (hsuc->desc) { |
353 | hsu_dma_desc_free(&hsuc->desc->vdesc); | |
354 | hsuc->desc = NULL; | |
355 | } | |
2b49e0c5 AS |
356 | |
357 | vchan_get_all_descriptors(&hsuc->vchan, &head); | |
358 | spin_unlock_irqrestore(&hsuc->vchan.lock, flags); | |
359 | vchan_dma_desc_free_list(&hsuc->vchan, &head); | |
360 | ||
361 | return 0; | |
362 | } | |
363 | ||
2b49e0c5 AS |
364 | static void hsu_dma_free_chan_resources(struct dma_chan *chan) |
365 | { | |
366 | vchan_free_chan_resources(to_virt_chan(chan)); | |
367 | } | |
368 | ||
369 | int hsu_dma_probe(struct hsu_dma_chip *chip) | |
370 | { | |
371 | struct hsu_dma *hsu; | |
2b49e0c5 AS |
372 | void __iomem *addr = chip->regs + chip->offset; |
373 | unsigned short i; | |
374 | int ret; | |
375 | ||
376 | hsu = devm_kzalloc(chip->dev, sizeof(*hsu), GFP_KERNEL); | |
377 | if (!hsu) | |
378 | return -ENOMEM; | |
379 | ||
380 | chip->hsu = hsu; | |
381 | ||
4c97ad99 HK |
382 | /* Calculate nr_channels from the IO space length */ |
383 | hsu->nr_channels = (chip->length - chip->offset) / HSU_DMA_CHAN_LENGTH; | |
2b49e0c5 | 384 | |
4c97ad99 | 385 | hsu->chan = devm_kcalloc(chip->dev, hsu->nr_channels, |
2b49e0c5 AS |
386 | sizeof(*hsu->chan), GFP_KERNEL); |
387 | if (!hsu->chan) | |
388 | return -ENOMEM; | |
389 | ||
390 | INIT_LIST_HEAD(&hsu->dma.channels); | |
4c97ad99 | 391 | for (i = 0; i < hsu->nr_channels; i++) { |
2b49e0c5 AS |
392 | struct hsu_dma_chan *hsuc = &hsu->chan[i]; |
393 | ||
394 | hsuc->vchan.desc_free = hsu_dma_desc_free; | |
395 | vchan_init(&hsuc->vchan, &hsu->dma); | |
396 | ||
397 | hsuc->direction = (i & 0x1) ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV; | |
398 | hsuc->reg = addr + i * HSU_DMA_CHAN_LENGTH; | |
2b49e0c5 AS |
399 | } |
400 | ||
401 | dma_cap_set(DMA_SLAVE, hsu->dma.cap_mask); | |
402 | dma_cap_set(DMA_PRIVATE, hsu->dma.cap_mask); | |
403 | ||
2b49e0c5 AS |
404 | hsu->dma.device_free_chan_resources = hsu_dma_free_chan_resources; |
405 | ||
406 | hsu->dma.device_prep_slave_sg = hsu_dma_prep_slave_sg; | |
407 | ||
408 | hsu->dma.device_issue_pending = hsu_dma_issue_pending; | |
409 | hsu->dma.device_tx_status = hsu_dma_tx_status; | |
410 | ||
411 | hsu->dma.device_config = hsu_dma_slave_config; | |
412 | hsu->dma.device_pause = hsu_dma_pause; | |
413 | hsu->dma.device_resume = hsu_dma_resume; | |
414 | hsu->dma.device_terminate_all = hsu_dma_terminate_all; | |
415 | ||
416 | hsu->dma.src_addr_widths = HSU_DMA_BUSWIDTHS; | |
417 | hsu->dma.dst_addr_widths = HSU_DMA_BUSWIDTHS; | |
418 | hsu->dma.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); | |
419 | hsu->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; | |
420 | ||
421 | hsu->dma.dev = chip->dev; | |
422 | ||
423 | ret = dma_async_device_register(&hsu->dma); | |
424 | if (ret) | |
425 | return ret; | |
426 | ||
4c97ad99 | 427 | dev_info(chip->dev, "Found HSU DMA, %d channels\n", hsu->nr_channels); |
2b49e0c5 AS |
428 | return 0; |
429 | } | |
430 | EXPORT_SYMBOL_GPL(hsu_dma_probe); | |
431 | ||
432 | int hsu_dma_remove(struct hsu_dma_chip *chip) | |
433 | { | |
434 | struct hsu_dma *hsu = chip->hsu; | |
435 | unsigned short i; | |
436 | ||
437 | dma_async_device_unregister(&hsu->dma); | |
438 | ||
4c97ad99 | 439 | for (i = 0; i < hsu->nr_channels; i++) { |
2b49e0c5 AS |
440 | struct hsu_dma_chan *hsuc = &hsu->chan[i]; |
441 | ||
442 | tasklet_kill(&hsuc->vchan.task); | |
443 | } | |
444 | ||
445 | return 0; | |
446 | } | |
447 | EXPORT_SYMBOL_GPL(hsu_dma_remove); | |
448 | ||
449 | MODULE_LICENSE("GPL v2"); | |
450 | MODULE_DESCRIPTION("High Speed UART DMA core driver"); | |
451 | MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>"); |