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