Commit | Line | Data |
---|---|---|
1b2e98bc AS |
1 | /* |
2 | * ACPI helpers for DMA request / controller | |
3 | * | |
4 | * Based on of-dma.c | |
5 | * | |
6 | * Copyright (C) 2013, Intel Corporation | |
ee8209fd AS |
7 | * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
8 | * Mika Westerberg <mika.westerberg@linux.intel.com> | |
1b2e98bc AS |
9 | * |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
15 | #include <linux/device.h> | |
0f6a928d | 16 | #include <linux/err.h> |
1b2e98bc | 17 | #include <linux/module.h> |
f94cf9f4 | 18 | #include <linux/kernel.h> |
1b2e98bc AS |
19 | #include <linux/list.h> |
20 | #include <linux/mutex.h> | |
21 | #include <linux/slab.h> | |
ee8209fd | 22 | #include <linux/ioport.h> |
1b2e98bc AS |
23 | #include <linux/acpi.h> |
24 | #include <linux/acpi_dma.h> | |
3f4232ee | 25 | #include <linux/property.h> |
1b2e98bc AS |
26 | |
27 | static LIST_HEAD(acpi_dma_list); | |
28 | static DEFINE_MUTEX(acpi_dma_lock); | |
29 | ||
ee8209fd AS |
30 | /** |
31 | * acpi_dma_parse_resource_group - match device and parse resource group | |
32 | * @grp: CSRT resource group | |
33 | * @adev: ACPI device to match with | |
34 | * @adma: struct acpi_dma of the given DMA controller | |
35 | * | |
ee8209fd AS |
36 | * In order to match a device from DSDT table to the corresponding CSRT device |
37 | * we use MMIO address and IRQ. | |
39d14478 AS |
38 | * |
39 | * Return: | |
40 | * 1 on success, 0 when no information is available, or appropriate errno value | |
41 | * on error. | |
ee8209fd AS |
42 | */ |
43 | static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, | |
44 | struct acpi_device *adev, struct acpi_dma *adma) | |
45 | { | |
46 | const struct acpi_csrt_shared_info *si; | |
47 | struct list_head resource_list; | |
90e97820 | 48 | struct resource_entry *rentry; |
ee8209fd | 49 | resource_size_t mem = 0, irq = 0; |
ee8209fd AS |
50 | int ret; |
51 | ||
52 | if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info)) | |
53 | return -ENODEV; | |
54 | ||
55 | INIT_LIST_HEAD(&resource_list); | |
56 | ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); | |
57 | if (ret <= 0) | |
58 | return 0; | |
59 | ||
60 | list_for_each_entry(rentry, &resource_list, node) { | |
90e97820 JL |
61 | if (resource_type(rentry->res) == IORESOURCE_MEM) |
62 | mem = rentry->res->start; | |
63 | else if (resource_type(rentry->res) == IORESOURCE_IRQ) | |
64 | irq = rentry->res->start; | |
ee8209fd AS |
65 | } |
66 | ||
67 | acpi_dev_free_resource_list(&resource_list); | |
68 | ||
69 | /* Consider initial zero values as resource not found */ | |
70 | if (mem == 0 && irq == 0) | |
71 | return 0; | |
72 | ||
73 | si = (const struct acpi_csrt_shared_info *)&grp[1]; | |
74 | ||
75 | /* Match device by MMIO and IRQ */ | |
f94cf9f4 AS |
76 | if (si->mmio_base_low != lower_32_bits(mem) || |
77 | si->mmio_base_high != upper_32_bits(mem) || | |
78 | si->gsi_interrupt != irq) | |
ee8209fd AS |
79 | return 0; |
80 | ||
ee8209fd | 81 | dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n", |
b4d6d336 | 82 | (char *)&grp->vendor_id, grp->device_id, grp->revision); |
ee8209fd AS |
83 | |
84 | /* Check if the request line range is available */ | |
85 | if (si->base_request_line == 0 && si->num_handshake_signals == 0) | |
86 | return 0; | |
87 | ||
88 | adma->base_request_line = si->base_request_line; | |
89 | adma->end_request_line = si->base_request_line + | |
90 | si->num_handshake_signals - 1; | |
91 | ||
92 | dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n", | |
93 | adma->base_request_line, adma->end_request_line); | |
94 | ||
95 | return 1; | |
96 | } | |
97 | ||
98 | /** | |
99 | * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources | |
100 | * @adev: ACPI device to match with | |
101 | * @adma: struct acpi_dma of the given DMA controller | |
102 | * | |
103 | * CSRT or Core System Resources Table is a proprietary ACPI table | |
104 | * introduced by Microsoft. This table can contain devices that are not in | |
105 | * the system DSDT table. In particular DMA controllers might be described | |
106 | * here. | |
107 | * | |
108 | * We are using this table to get the request line range of the specific DMA | |
109 | * controller to be used later. | |
ee8209fd AS |
110 | */ |
111 | static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma) | |
112 | { | |
113 | struct acpi_csrt_group *grp, *end; | |
114 | struct acpi_table_csrt *csrt; | |
115 | acpi_status status; | |
116 | int ret; | |
117 | ||
118 | status = acpi_get_table(ACPI_SIG_CSRT, 0, | |
119 | (struct acpi_table_header **)&csrt); | |
120 | if (ACPI_FAILURE(status)) { | |
121 | if (status != AE_NOT_FOUND) | |
122 | dev_warn(&adev->dev, "failed to get the CSRT table\n"); | |
123 | return; | |
124 | } | |
125 | ||
126 | grp = (struct acpi_csrt_group *)(csrt + 1); | |
127 | end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length); | |
128 | ||
129 | while (grp < end) { | |
130 | ret = acpi_dma_parse_resource_group(grp, adev, adma); | |
131 | if (ret < 0) { | |
132 | dev_warn(&adev->dev, | |
133 | "error in parsing resource group\n"); | |
134 | return; | |
135 | } | |
136 | ||
137 | grp = (struct acpi_csrt_group *)((void *)grp + grp->length); | |
138 | } | |
139 | } | |
140 | ||
1b2e98bc AS |
141 | /** |
142 | * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers | |
143 | * @dev: struct device of DMA controller | |
144 | * @acpi_dma_xlate: translation function which converts a dma specifier | |
145 | * into a dma_chan structure | |
146 | * @data pointer to controller specific data to be used by | |
147 | * translation function | |
148 | * | |
1b2e98bc AS |
149 | * Allocated memory should be freed with appropriate acpi_dma_controller_free() |
150 | * call. | |
39d14478 AS |
151 | * |
152 | * Return: | |
153 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
154 | */ |
155 | int acpi_dma_controller_register(struct device *dev, | |
156 | struct dma_chan *(*acpi_dma_xlate) | |
157 | (struct acpi_dma_spec *, struct acpi_dma *), | |
158 | void *data) | |
159 | { | |
160 | struct acpi_device *adev; | |
161 | struct acpi_dma *adma; | |
162 | ||
163 | if (!dev || !acpi_dma_xlate) | |
164 | return -EINVAL; | |
165 | ||
166 | /* Check if the device was enumerated by ACPI */ | |
aff1e0ce JN |
167 | adev = ACPI_COMPANION(dev); |
168 | if (!adev) | |
1b2e98bc AS |
169 | return -EINVAL; |
170 | ||
171 | adma = kzalloc(sizeof(*adma), GFP_KERNEL); | |
172 | if (!adma) | |
173 | return -ENOMEM; | |
174 | ||
175 | adma->dev = dev; | |
176 | adma->acpi_dma_xlate = acpi_dma_xlate; | |
177 | adma->data = data; | |
178 | ||
ee8209fd AS |
179 | acpi_dma_parse_csrt(adev, adma); |
180 | ||
1b2e98bc AS |
181 | /* Now queue acpi_dma controller structure in list */ |
182 | mutex_lock(&acpi_dma_lock); | |
183 | list_add_tail(&adma->dma_controllers, &acpi_dma_list); | |
184 | mutex_unlock(&acpi_dma_lock); | |
185 | ||
186 | return 0; | |
187 | } | |
188 | EXPORT_SYMBOL_GPL(acpi_dma_controller_register); | |
189 | ||
190 | /** | |
191 | * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list | |
192 | * @dev: struct device of DMA controller | |
193 | * | |
194 | * Memory allocated by acpi_dma_controller_register() is freed here. | |
39d14478 AS |
195 | * |
196 | * Return: | |
197 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
198 | */ |
199 | int acpi_dma_controller_free(struct device *dev) | |
200 | { | |
201 | struct acpi_dma *adma; | |
202 | ||
203 | if (!dev) | |
204 | return -EINVAL; | |
205 | ||
206 | mutex_lock(&acpi_dma_lock); | |
207 | ||
208 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) | |
209 | if (adma->dev == dev) { | |
210 | list_del(&adma->dma_controllers); | |
211 | mutex_unlock(&acpi_dma_lock); | |
212 | kfree(adma); | |
213 | return 0; | |
214 | } | |
215 | ||
216 | mutex_unlock(&acpi_dma_lock); | |
217 | return -ENODEV; | |
218 | } | |
219 | EXPORT_SYMBOL_GPL(acpi_dma_controller_free); | |
220 | ||
221 | static void devm_acpi_dma_release(struct device *dev, void *res) | |
222 | { | |
223 | acpi_dma_controller_free(dev); | |
224 | } | |
225 | ||
226 | /** | |
227 | * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register() | |
228 | * @dev: device that is registering this DMA controller | |
229 | * @acpi_dma_xlate: translation function | |
230 | * @data pointer to controller specific data | |
231 | * | |
232 | * Managed acpi_dma_controller_register(). DMA controller registered by this | |
233 | * function are automatically freed on driver detach. See | |
234 | * acpi_dma_controller_register() for more information. | |
39d14478 AS |
235 | * |
236 | * Return: | |
237 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
238 | */ |
239 | int devm_acpi_dma_controller_register(struct device *dev, | |
240 | struct dma_chan *(*acpi_dma_xlate) | |
241 | (struct acpi_dma_spec *, struct acpi_dma *), | |
242 | void *data) | |
243 | { | |
244 | void *res; | |
245 | int ret; | |
246 | ||
247 | res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL); | |
248 | if (!res) | |
249 | return -ENOMEM; | |
250 | ||
251 | ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data); | |
252 | if (ret) { | |
253 | devres_free(res); | |
254 | return ret; | |
255 | } | |
256 | devres_add(dev, res); | |
257 | return 0; | |
258 | } | |
259 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register); | |
260 | ||
261 | /** | |
262 | * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free() | |
263 | * | |
264 | * Unregister a DMA controller registered with | |
265 | * devm_acpi_dma_controller_register(). Normally this function will not need to | |
266 | * be called and the resource management code will ensure that the resource is | |
267 | * freed. | |
268 | */ | |
269 | void devm_acpi_dma_controller_free(struct device *dev) | |
270 | { | |
8f012583 | 271 | WARN_ON(devres_release(dev, devm_acpi_dma_release, NULL, NULL)); |
1b2e98bc AS |
272 | } |
273 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); | |
274 | ||
ee8209fd AS |
275 | /** |
276 | * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function | |
277 | * @adma: struct acpi_dma of DMA controller | |
278 | * @dma_spec: dma specifier to update | |
279 | * | |
ee8209fd AS |
280 | * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource |
281 | * Descriptor": | |
282 | * DMA Request Line bits is a platform-relative number uniquely | |
283 | * identifying the request line assigned. Request line-to-Controller | |
284 | * mapping is done in a controller-specific OS driver. | |
285 | * That's why we can safely adjust slave_id when the appropriate controller is | |
286 | * found. | |
39d14478 AS |
287 | * |
288 | * Return: | |
289 | * 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. | |
ee8209fd AS |
290 | */ |
291 | static int acpi_dma_update_dma_spec(struct acpi_dma *adma, | |
292 | struct acpi_dma_spec *dma_spec) | |
293 | { | |
294 | /* Set link to the DMA controller device */ | |
295 | dma_spec->dev = adma->dev; | |
296 | ||
297 | /* Check if the request line range is available */ | |
298 | if (adma->base_request_line == 0 && adma->end_request_line == 0) | |
299 | return 0; | |
300 | ||
301 | /* Check if slave_id falls to the range */ | |
302 | if (dma_spec->slave_id < adma->base_request_line || | |
303 | dma_spec->slave_id > adma->end_request_line) | |
304 | return -1; | |
305 | ||
306 | /* | |
307 | * Here we adjust slave_id. It should be a relative number to the base | |
308 | * request line. | |
309 | */ | |
310 | dma_spec->slave_id -= adma->base_request_line; | |
311 | ||
312 | return 1; | |
313 | } | |
314 | ||
1b2e98bc AS |
315 | struct acpi_dma_parser_data { |
316 | struct acpi_dma_spec dma_spec; | |
317 | size_t index; | |
318 | size_t n; | |
319 | }; | |
320 | ||
321 | /** | |
322 | * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier | |
323 | * @res: struct acpi_resource to get FixedDMA resources from | |
324 | * @data: pointer to a helper struct acpi_dma_parser_data | |
325 | */ | |
326 | static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) | |
327 | { | |
328 | struct acpi_dma_parser_data *pdata = data; | |
329 | ||
330 | if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) { | |
331 | struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma; | |
332 | ||
333 | if (pdata->n++ == pdata->index) { | |
334 | pdata->dma_spec.chan_id = dma->channels; | |
335 | pdata->dma_spec.slave_id = dma->request_lines; | |
336 | } | |
337 | } | |
338 | ||
339 | /* Tell the ACPI core to skip this resource */ | |
340 | return 1; | |
341 | } | |
342 | ||
343 | /** | |
344 | * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel | |
345 | * @dev: struct device to get DMA request from | |
346 | * @index: index of FixedDMA descriptor for @dev | |
347 | * | |
39d14478 | 348 | * Return: |
0f6a928d | 349 | * Pointer to appropriate dma channel on success or an error pointer. |
1b2e98bc AS |
350 | */ |
351 | struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, | |
352 | size_t index) | |
353 | { | |
354 | struct acpi_dma_parser_data pdata; | |
355 | struct acpi_dma_spec *dma_spec = &pdata.dma_spec; | |
356 | struct list_head resource_list; | |
357 | struct acpi_device *adev; | |
358 | struct acpi_dma *adma; | |
359 | struct dma_chan *chan = NULL; | |
ee8209fd | 360 | int found; |
1b2e98bc AS |
361 | |
362 | /* Check if the device was enumerated by ACPI */ | |
aff1e0ce | 363 | if (!dev) |
0f6a928d | 364 | return ERR_PTR(-ENODEV); |
1b2e98bc | 365 | |
aff1e0ce JN |
366 | adev = ACPI_COMPANION(dev); |
367 | if (!adev) | |
0f6a928d | 368 | return ERR_PTR(-ENODEV); |
1b2e98bc AS |
369 | |
370 | memset(&pdata, 0, sizeof(pdata)); | |
371 | pdata.index = index; | |
372 | ||
373 | /* Initial values for the request line and channel */ | |
374 | dma_spec->chan_id = -1; | |
375 | dma_spec->slave_id = -1; | |
376 | ||
377 | INIT_LIST_HEAD(&resource_list); | |
378 | acpi_dev_get_resources(adev, &resource_list, | |
379 | acpi_dma_parse_fixed_dma, &pdata); | |
380 | acpi_dev_free_resource_list(&resource_list); | |
381 | ||
382 | if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) | |
0f6a928d | 383 | return ERR_PTR(-ENODEV); |
1b2e98bc AS |
384 | |
385 | mutex_lock(&acpi_dma_lock); | |
386 | ||
387 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) { | |
ee8209fd AS |
388 | /* |
389 | * We are not going to call translation function if slave_id | |
390 | * doesn't fall to the request range. | |
391 | */ | |
392 | found = acpi_dma_update_dma_spec(adma, dma_spec); | |
393 | if (found < 0) | |
394 | continue; | |
1b2e98bc | 395 | chan = adma->acpi_dma_xlate(dma_spec, adma); |
ee8209fd AS |
396 | /* |
397 | * Try to get a channel only from the DMA controller that | |
398 | * matches the slave_id. See acpi_dma_update_dma_spec() | |
399 | * description for the details. | |
400 | */ | |
401 | if (found > 0 || chan) | |
1b2e98bc AS |
402 | break; |
403 | } | |
404 | ||
405 | mutex_unlock(&acpi_dma_lock); | |
0f6a928d | 406 | return chan ? chan : ERR_PTR(-EPROBE_DEFER); |
1b2e98bc AS |
407 | } |
408 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); | |
409 | ||
410 | /** | |
411 | * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel | |
412 | * @dev: struct device to get DMA request from | |
413 | * @name: represents corresponding FixedDMA descriptor for @dev | |
414 | * | |
415 | * In order to support both Device Tree and ACPI in a single driver we | |
416 | * translate the names "tx" and "rx" here based on the most common case where | |
417 | * the first FixedDMA descriptor is TX and second is RX. | |
418 | * | |
3f4232ee MW |
419 | * If the device has "dma-names" property the FixedDMA descriptor indices |
420 | * are retrieved based on those. Otherwise the function falls back using | |
421 | * hardcoded indices. | |
422 | * | |
39d14478 | 423 | * Return: |
0f6a928d | 424 | * Pointer to appropriate dma channel on success or an error pointer. |
1b2e98bc AS |
425 | */ |
426 | struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, | |
427 | const char *name) | |
428 | { | |
3f4232ee MW |
429 | int index; |
430 | ||
431 | index = device_property_match_string(dev, "dma-names", name); | |
432 | if (index < 0) { | |
433 | if (!strcmp(name, "tx")) | |
434 | index = 0; | |
435 | else if (!strcmp(name, "rx")) | |
436 | index = 1; | |
437 | else | |
438 | return ERR_PTR(-ENODEV); | |
439 | } | |
1b2e98bc | 440 | |
36bf8fc4 | 441 | dev_dbg(dev, "Looking for DMA channel \"%s\" at index %d...\n", name, index); |
1b2e98bc AS |
442 | return acpi_dma_request_slave_chan_by_index(dev, index); |
443 | } | |
444 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name); | |
445 | ||
446 | /** | |
447 | * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper | |
448 | * @dma_spec: pointer to ACPI DMA specifier | |
449 | * @adma: pointer to ACPI DMA controller data | |
450 | * | |
451 | * A simple translation function for ACPI based devices. Passes &struct | |
39d14478 AS |
452 | * dma_spec to the DMA controller driver provided filter function. |
453 | * | |
454 | * Return: | |
455 | * Pointer to the channel if found or %NULL otherwise. | |
1b2e98bc AS |
456 | */ |
457 | struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, | |
458 | struct acpi_dma *adma) | |
459 | { | |
460 | struct acpi_dma_filter_info *info = adma->data; | |
461 | ||
462 | if (!info || !info->filter_fn) | |
463 | return NULL; | |
464 | ||
465 | return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec); | |
466 | } | |
467 | EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate); |