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> | |
16 | #include <linux/module.h> | |
17 | #include <linux/list.h> | |
18 | #include <linux/mutex.h> | |
19 | #include <linux/slab.h> | |
ee8209fd | 20 | #include <linux/ioport.h> |
1b2e98bc AS |
21 | #include <linux/acpi.h> |
22 | #include <linux/acpi_dma.h> | |
23 | ||
24 | static LIST_HEAD(acpi_dma_list); | |
25 | static DEFINE_MUTEX(acpi_dma_lock); | |
26 | ||
ee8209fd AS |
27 | /** |
28 | * acpi_dma_parse_resource_group - match device and parse resource group | |
29 | * @grp: CSRT resource group | |
30 | * @adev: ACPI device to match with | |
31 | * @adma: struct acpi_dma of the given DMA controller | |
32 | * | |
33 | * Returns 1 on success, 0 when no information is available, or appropriate | |
34 | * errno value on error. | |
35 | * | |
36 | * In order to match a device from DSDT table to the corresponding CSRT device | |
37 | * we use MMIO address and IRQ. | |
38 | */ | |
39 | static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, | |
40 | struct acpi_device *adev, struct acpi_dma *adma) | |
41 | { | |
42 | const struct acpi_csrt_shared_info *si; | |
43 | struct list_head resource_list; | |
44 | struct resource_list_entry *rentry; | |
45 | resource_size_t mem = 0, irq = 0; | |
46 | u32 vendor_id; | |
47 | int ret; | |
48 | ||
49 | if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info)) | |
50 | return -ENODEV; | |
51 | ||
52 | INIT_LIST_HEAD(&resource_list); | |
53 | ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); | |
54 | if (ret <= 0) | |
55 | return 0; | |
56 | ||
57 | list_for_each_entry(rentry, &resource_list, node) { | |
58 | if (resource_type(&rentry->res) == IORESOURCE_MEM) | |
59 | mem = rentry->res.start; | |
60 | else if (resource_type(&rentry->res) == IORESOURCE_IRQ) | |
61 | irq = rentry->res.start; | |
62 | } | |
63 | ||
64 | acpi_dev_free_resource_list(&resource_list); | |
65 | ||
66 | /* Consider initial zero values as resource not found */ | |
67 | if (mem == 0 && irq == 0) | |
68 | return 0; | |
69 | ||
70 | si = (const struct acpi_csrt_shared_info *)&grp[1]; | |
71 | ||
72 | /* Match device by MMIO and IRQ */ | |
73 | if (si->mmio_base_low != mem || si->gsi_interrupt != irq) | |
74 | return 0; | |
75 | ||
4aed508f | 76 | vendor_id = le32_to_cpu((__force __le32)grp->vendor_id); |
ee8209fd AS |
77 | dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n", |
78 | (char *)&vendor_id, grp->device_id, grp->revision); | |
79 | ||
80 | /* Check if the request line range is available */ | |
81 | if (si->base_request_line == 0 && si->num_handshake_signals == 0) | |
82 | return 0; | |
83 | ||
84 | adma->base_request_line = si->base_request_line; | |
85 | adma->end_request_line = si->base_request_line + | |
86 | si->num_handshake_signals - 1; | |
87 | ||
88 | dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n", | |
89 | adma->base_request_line, adma->end_request_line); | |
90 | ||
91 | return 1; | |
92 | } | |
93 | ||
94 | /** | |
95 | * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources | |
96 | * @adev: ACPI device to match with | |
97 | * @adma: struct acpi_dma of the given DMA controller | |
98 | * | |
99 | * CSRT or Core System Resources Table is a proprietary ACPI table | |
100 | * introduced by Microsoft. This table can contain devices that are not in | |
101 | * the system DSDT table. In particular DMA controllers might be described | |
102 | * here. | |
103 | * | |
104 | * We are using this table to get the request line range of the specific DMA | |
105 | * controller to be used later. | |
106 | * | |
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 | * | |
146 | * Returns 0 on success or appropriate errno value on error. | |
147 | * | |
148 | * Allocated memory should be freed with appropriate acpi_dma_controller_free() | |
149 | * call. | |
150 | */ | |
151 | int acpi_dma_controller_register(struct device *dev, | |
152 | struct dma_chan *(*acpi_dma_xlate) | |
153 | (struct acpi_dma_spec *, struct acpi_dma *), | |
154 | void *data) | |
155 | { | |
156 | struct acpi_device *adev; | |
157 | struct acpi_dma *adma; | |
158 | ||
159 | if (!dev || !acpi_dma_xlate) | |
160 | return -EINVAL; | |
161 | ||
162 | /* Check if the device was enumerated by ACPI */ | |
163 | if (!ACPI_HANDLE(dev)) | |
164 | return -EINVAL; | |
165 | ||
166 | if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev)) | |
167 | return -EINVAL; | |
168 | ||
169 | adma = kzalloc(sizeof(*adma), GFP_KERNEL); | |
170 | if (!adma) | |
171 | return -ENOMEM; | |
172 | ||
173 | adma->dev = dev; | |
174 | adma->acpi_dma_xlate = acpi_dma_xlate; | |
175 | adma->data = data; | |
176 | ||
ee8209fd AS |
177 | acpi_dma_parse_csrt(adev, adma); |
178 | ||
1b2e98bc AS |
179 | /* Now queue acpi_dma controller structure in list */ |
180 | mutex_lock(&acpi_dma_lock); | |
181 | list_add_tail(&adma->dma_controllers, &acpi_dma_list); | |
182 | mutex_unlock(&acpi_dma_lock); | |
183 | ||
184 | return 0; | |
185 | } | |
186 | EXPORT_SYMBOL_GPL(acpi_dma_controller_register); | |
187 | ||
188 | /** | |
189 | * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list | |
190 | * @dev: struct device of DMA controller | |
191 | * | |
192 | * Memory allocated by acpi_dma_controller_register() is freed here. | |
193 | */ | |
194 | int acpi_dma_controller_free(struct device *dev) | |
195 | { | |
196 | struct acpi_dma *adma; | |
197 | ||
198 | if (!dev) | |
199 | return -EINVAL; | |
200 | ||
201 | mutex_lock(&acpi_dma_lock); | |
202 | ||
203 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) | |
204 | if (adma->dev == dev) { | |
205 | list_del(&adma->dma_controllers); | |
206 | mutex_unlock(&acpi_dma_lock); | |
207 | kfree(adma); | |
208 | return 0; | |
209 | } | |
210 | ||
211 | mutex_unlock(&acpi_dma_lock); | |
212 | return -ENODEV; | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(acpi_dma_controller_free); | |
215 | ||
216 | static void devm_acpi_dma_release(struct device *dev, void *res) | |
217 | { | |
218 | acpi_dma_controller_free(dev); | |
219 | } | |
220 | ||
221 | /** | |
222 | * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register() | |
223 | * @dev: device that is registering this DMA controller | |
224 | * @acpi_dma_xlate: translation function | |
225 | * @data pointer to controller specific data | |
226 | * | |
227 | * Managed acpi_dma_controller_register(). DMA controller registered by this | |
228 | * function are automatically freed on driver detach. See | |
229 | * acpi_dma_controller_register() for more information. | |
230 | */ | |
231 | int devm_acpi_dma_controller_register(struct device *dev, | |
232 | struct dma_chan *(*acpi_dma_xlate) | |
233 | (struct acpi_dma_spec *, struct acpi_dma *), | |
234 | void *data) | |
235 | { | |
236 | void *res; | |
237 | int ret; | |
238 | ||
239 | res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL); | |
240 | if (!res) | |
241 | return -ENOMEM; | |
242 | ||
243 | ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data); | |
244 | if (ret) { | |
245 | devres_free(res); | |
246 | return ret; | |
247 | } | |
248 | devres_add(dev, res); | |
249 | return 0; | |
250 | } | |
251 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register); | |
252 | ||
253 | /** | |
254 | * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free() | |
255 | * | |
256 | * Unregister a DMA controller registered with | |
257 | * devm_acpi_dma_controller_register(). Normally this function will not need to | |
258 | * be called and the resource management code will ensure that the resource is | |
259 | * freed. | |
260 | */ | |
261 | void devm_acpi_dma_controller_free(struct device *dev) | |
262 | { | |
263 | WARN_ON(devres_destroy(dev, devm_acpi_dma_release, NULL, NULL)); | |
264 | } | |
265 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); | |
266 | ||
ee8209fd AS |
267 | /** |
268 | * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function | |
269 | * @adma: struct acpi_dma of DMA controller | |
270 | * @dma_spec: dma specifier to update | |
271 | * | |
272 | * Returns 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. | |
273 | * | |
274 | * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource | |
275 | * Descriptor": | |
276 | * DMA Request Line bits is a platform-relative number uniquely | |
277 | * identifying the request line assigned. Request line-to-Controller | |
278 | * mapping is done in a controller-specific OS driver. | |
279 | * That's why we can safely adjust slave_id when the appropriate controller is | |
280 | * found. | |
281 | */ | |
282 | static int acpi_dma_update_dma_spec(struct acpi_dma *adma, | |
283 | struct acpi_dma_spec *dma_spec) | |
284 | { | |
285 | /* Set link to the DMA controller device */ | |
286 | dma_spec->dev = adma->dev; | |
287 | ||
288 | /* Check if the request line range is available */ | |
289 | if (adma->base_request_line == 0 && adma->end_request_line == 0) | |
290 | return 0; | |
291 | ||
292 | /* Check if slave_id falls to the range */ | |
293 | if (dma_spec->slave_id < adma->base_request_line || | |
294 | dma_spec->slave_id > adma->end_request_line) | |
295 | return -1; | |
296 | ||
297 | /* | |
298 | * Here we adjust slave_id. It should be a relative number to the base | |
299 | * request line. | |
300 | */ | |
301 | dma_spec->slave_id -= adma->base_request_line; | |
302 | ||
303 | return 1; | |
304 | } | |
305 | ||
1b2e98bc AS |
306 | struct acpi_dma_parser_data { |
307 | struct acpi_dma_spec dma_spec; | |
308 | size_t index; | |
309 | size_t n; | |
310 | }; | |
311 | ||
312 | /** | |
313 | * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier | |
314 | * @res: struct acpi_resource to get FixedDMA resources from | |
315 | * @data: pointer to a helper struct acpi_dma_parser_data | |
316 | */ | |
317 | static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) | |
318 | { | |
319 | struct acpi_dma_parser_data *pdata = data; | |
320 | ||
321 | if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) { | |
322 | struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma; | |
323 | ||
324 | if (pdata->n++ == pdata->index) { | |
325 | pdata->dma_spec.chan_id = dma->channels; | |
326 | pdata->dma_spec.slave_id = dma->request_lines; | |
327 | } | |
328 | } | |
329 | ||
330 | /* Tell the ACPI core to skip this resource */ | |
331 | return 1; | |
332 | } | |
333 | ||
334 | /** | |
335 | * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel | |
336 | * @dev: struct device to get DMA request from | |
337 | * @index: index of FixedDMA descriptor for @dev | |
338 | * | |
339 | * Returns pointer to appropriate dma channel on success or NULL on error. | |
340 | */ | |
341 | struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, | |
342 | size_t index) | |
343 | { | |
344 | struct acpi_dma_parser_data pdata; | |
345 | struct acpi_dma_spec *dma_spec = &pdata.dma_spec; | |
346 | struct list_head resource_list; | |
347 | struct acpi_device *adev; | |
348 | struct acpi_dma *adma; | |
349 | struct dma_chan *chan = NULL; | |
ee8209fd | 350 | int found; |
1b2e98bc AS |
351 | |
352 | /* Check if the device was enumerated by ACPI */ | |
353 | if (!dev || !ACPI_HANDLE(dev)) | |
354 | return NULL; | |
355 | ||
356 | if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev)) | |
357 | return NULL; | |
358 | ||
359 | memset(&pdata, 0, sizeof(pdata)); | |
360 | pdata.index = index; | |
361 | ||
362 | /* Initial values for the request line and channel */ | |
363 | dma_spec->chan_id = -1; | |
364 | dma_spec->slave_id = -1; | |
365 | ||
366 | INIT_LIST_HEAD(&resource_list); | |
367 | acpi_dev_get_resources(adev, &resource_list, | |
368 | acpi_dma_parse_fixed_dma, &pdata); | |
369 | acpi_dev_free_resource_list(&resource_list); | |
370 | ||
371 | if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) | |
372 | return NULL; | |
373 | ||
374 | mutex_lock(&acpi_dma_lock); | |
375 | ||
376 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) { | |
ee8209fd AS |
377 | /* |
378 | * We are not going to call translation function if slave_id | |
379 | * doesn't fall to the request range. | |
380 | */ | |
381 | found = acpi_dma_update_dma_spec(adma, dma_spec); | |
382 | if (found < 0) | |
383 | continue; | |
1b2e98bc | 384 | chan = adma->acpi_dma_xlate(dma_spec, adma); |
ee8209fd AS |
385 | /* |
386 | * Try to get a channel only from the DMA controller that | |
387 | * matches the slave_id. See acpi_dma_update_dma_spec() | |
388 | * description for the details. | |
389 | */ | |
390 | if (found > 0 || chan) | |
1b2e98bc AS |
391 | break; |
392 | } | |
393 | ||
394 | mutex_unlock(&acpi_dma_lock); | |
395 | return chan; | |
396 | } | |
397 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); | |
398 | ||
399 | /** | |
400 | * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel | |
401 | * @dev: struct device to get DMA request from | |
402 | * @name: represents corresponding FixedDMA descriptor for @dev | |
403 | * | |
404 | * In order to support both Device Tree and ACPI in a single driver we | |
405 | * translate the names "tx" and "rx" here based on the most common case where | |
406 | * the first FixedDMA descriptor is TX and second is RX. | |
407 | * | |
408 | * Returns pointer to appropriate dma channel on success or NULL on error. | |
409 | */ | |
410 | struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, | |
411 | const char *name) | |
412 | { | |
413 | size_t index; | |
414 | ||
415 | if (!strcmp(name, "tx")) | |
416 | index = 0; | |
417 | else if (!strcmp(name, "rx")) | |
418 | index = 1; | |
419 | else | |
420 | return NULL; | |
421 | ||
422 | return acpi_dma_request_slave_chan_by_index(dev, index); | |
423 | } | |
424 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name); | |
425 | ||
426 | /** | |
427 | * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper | |
428 | * @dma_spec: pointer to ACPI DMA specifier | |
429 | * @adma: pointer to ACPI DMA controller data | |
430 | * | |
431 | * A simple translation function for ACPI based devices. Passes &struct | |
432 | * dma_spec to the DMA controller driver provided filter function. Returns | |
433 | * pointer to the channel if found or %NULL otherwise. | |
434 | */ | |
435 | struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, | |
436 | struct acpi_dma *adma) | |
437 | { | |
438 | struct acpi_dma_filter_info *info = adma->data; | |
439 | ||
440 | if (!info || !info->filter_fn) | |
441 | return NULL; | |
442 | ||
443 | return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec); | |
444 | } | |
445 | EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate); |