Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1b2e98bc AS |
2 | /* |
3 | * ACPI helpers for DMA request / controller | |
4 | * | |
5 | * Based on of-dma.c | |
6 | * | |
7 | * Copyright (C) 2013, Intel Corporation | |
ee8209fd AS |
8 | * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
9 | * Mika Westerberg <mika.westerberg@linux.intel.com> | |
1b2e98bc AS |
10 | */ |
11 | ||
12 | #include <linux/device.h> | |
a6bc3323 | 13 | #include <linux/dma-mapping.h> |
0f6a928d | 14 | #include <linux/err.h> |
1b2e98bc | 15 | #include <linux/module.h> |
f94cf9f4 | 16 | #include <linux/kernel.h> |
1b2e98bc AS |
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> | |
3f4232ee | 23 | #include <linux/property.h> |
1b2e98bc AS |
24 | |
25 | static LIST_HEAD(acpi_dma_list); | |
26 | static DEFINE_MUTEX(acpi_dma_lock); | |
27 | ||
ee8209fd AS |
28 | /** |
29 | * acpi_dma_parse_resource_group - match device and parse resource group | |
30 | * @grp: CSRT resource group | |
31 | * @adev: ACPI device to match with | |
32 | * @adma: struct acpi_dma of the given DMA controller | |
33 | * | |
ee8209fd AS |
34 | * In order to match a device from DSDT table to the corresponding CSRT device |
35 | * we use MMIO address and IRQ. | |
39d14478 AS |
36 | * |
37 | * Return: | |
38 | * 1 on success, 0 when no information is available, or appropriate errno value | |
39 | * on error. | |
ee8209fd AS |
40 | */ |
41 | static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, | |
42 | struct acpi_device *adev, struct acpi_dma *adma) | |
43 | { | |
44 | const struct acpi_csrt_shared_info *si; | |
45 | struct list_head resource_list; | |
90e97820 | 46 | struct resource_entry *rentry; |
ee8209fd | 47 | resource_size_t mem = 0, irq = 0; |
ee8209fd AS |
48 | int ret; |
49 | ||
50 | if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info)) | |
51 | return -ENODEV; | |
52 | ||
53 | INIT_LIST_HEAD(&resource_list); | |
54 | ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); | |
55 | if (ret <= 0) | |
56 | return 0; | |
57 | ||
58 | list_for_each_entry(rentry, &resource_list, node) { | |
90e97820 JL |
59 | if (resource_type(rentry->res) == IORESOURCE_MEM) |
60 | mem = rentry->res->start; | |
61 | else if (resource_type(rentry->res) == IORESOURCE_IRQ) | |
62 | irq = rentry->res->start; | |
ee8209fd AS |
63 | } |
64 | ||
65 | acpi_dev_free_resource_list(&resource_list); | |
66 | ||
67 | /* Consider initial zero values as resource not found */ | |
68 | if (mem == 0 && irq == 0) | |
69 | return 0; | |
70 | ||
71 | si = (const struct acpi_csrt_shared_info *)&grp[1]; | |
72 | ||
67db87dc | 73 | /* Match device by MMIO */ |
f94cf9f4 | 74 | if (si->mmio_base_low != lower_32_bits(mem) || |
67db87dc AS |
75 | si->mmio_base_high != upper_32_bits(mem)) |
76 | return 0; | |
77 | ||
15cb0321 AS |
78 | /* |
79 | * acpi_gsi_to_irq() can't be used because some platforms do not save | |
80 | * registered IRQs in the MP table. Instead we just try to register | |
81 | * the GSI, which is the core part of the above mentioned function. | |
82 | */ | |
67db87dc | 83 | ret = acpi_register_gsi(NULL, si->gsi_interrupt, si->interrupt_mode, si->interrupt_polarity); |
15cb0321 AS |
84 | if (ret < 0) |
85 | return 0; | |
86 | ||
87 | /* Match device by Linux vIRQ */ | |
67db87dc | 88 | if (ret != irq) |
ee8209fd AS |
89 | return 0; |
90 | ||
ee8209fd | 91 | dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n", |
b4d6d336 | 92 | (char *)&grp->vendor_id, grp->device_id, grp->revision); |
ee8209fd AS |
93 | |
94 | /* Check if the request line range is available */ | |
95 | if (si->base_request_line == 0 && si->num_handshake_signals == 0) | |
96 | return 0; | |
97 | ||
a6bc3323 AS |
98 | /* Set up DMA mask based on value from CSRT */ |
99 | ret = dma_coerce_mask_and_coherent(&adev->dev, | |
100 | DMA_BIT_MASK(si->dma_address_width)); | |
101 | if (ret) | |
102 | return 0; | |
103 | ||
ee8209fd AS |
104 | adma->base_request_line = si->base_request_line; |
105 | adma->end_request_line = si->base_request_line + | |
106 | si->num_handshake_signals - 1; | |
107 | ||
108 | dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n", | |
109 | adma->base_request_line, adma->end_request_line); | |
110 | ||
111 | return 1; | |
112 | } | |
113 | ||
114 | /** | |
115 | * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources | |
116 | * @adev: ACPI device to match with | |
117 | * @adma: struct acpi_dma of the given DMA controller | |
118 | * | |
119 | * CSRT or Core System Resources Table is a proprietary ACPI table | |
120 | * introduced by Microsoft. This table can contain devices that are not in | |
121 | * the system DSDT table. In particular DMA controllers might be described | |
122 | * here. | |
123 | * | |
124 | * We are using this table to get the request line range of the specific DMA | |
125 | * controller to be used later. | |
ee8209fd AS |
126 | */ |
127 | static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma) | |
128 | { | |
129 | struct acpi_csrt_group *grp, *end; | |
130 | struct acpi_table_csrt *csrt; | |
131 | acpi_status status; | |
132 | int ret; | |
133 | ||
134 | status = acpi_get_table(ACPI_SIG_CSRT, 0, | |
135 | (struct acpi_table_header **)&csrt); | |
136 | if (ACPI_FAILURE(status)) { | |
137 | if (status != AE_NOT_FOUND) | |
138 | dev_warn(&adev->dev, "failed to get the CSRT table\n"); | |
139 | return; | |
140 | } | |
141 | ||
142 | grp = (struct acpi_csrt_group *)(csrt + 1); | |
143 | end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length); | |
144 | ||
145 | while (grp < end) { | |
146 | ret = acpi_dma_parse_resource_group(grp, adev, adma); | |
147 | if (ret < 0) { | |
148 | dev_warn(&adev->dev, | |
149 | "error in parsing resource group\n"); | |
7eb48dd0 | 150 | break; |
ee8209fd AS |
151 | } |
152 | ||
153 | grp = (struct acpi_csrt_group *)((void *)grp + grp->length); | |
154 | } | |
7eb48dd0 HG |
155 | |
156 | acpi_put_table((struct acpi_table_header *)csrt); | |
ee8209fd AS |
157 | } |
158 | ||
1b2e98bc AS |
159 | /** |
160 | * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers | |
161 | * @dev: struct device of DMA controller | |
162 | * @acpi_dma_xlate: translation function which converts a dma specifier | |
163 | * into a dma_chan structure | |
4b8584ba | 164 | * @data: pointer to controller specific data to be used by |
1b2e98bc AS |
165 | * translation function |
166 | * | |
1b2e98bc AS |
167 | * Allocated memory should be freed with appropriate acpi_dma_controller_free() |
168 | * call. | |
39d14478 AS |
169 | * |
170 | * Return: | |
171 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
172 | */ |
173 | int acpi_dma_controller_register(struct device *dev, | |
174 | struct dma_chan *(*acpi_dma_xlate) | |
175 | (struct acpi_dma_spec *, struct acpi_dma *), | |
176 | void *data) | |
177 | { | |
178 | struct acpi_device *adev; | |
179 | struct acpi_dma *adma; | |
180 | ||
181 | if (!dev || !acpi_dma_xlate) | |
182 | return -EINVAL; | |
183 | ||
184 | /* Check if the device was enumerated by ACPI */ | |
aff1e0ce JN |
185 | adev = ACPI_COMPANION(dev); |
186 | if (!adev) | |
1b2e98bc AS |
187 | return -EINVAL; |
188 | ||
189 | adma = kzalloc(sizeof(*adma), GFP_KERNEL); | |
190 | if (!adma) | |
191 | return -ENOMEM; | |
192 | ||
193 | adma->dev = dev; | |
194 | adma->acpi_dma_xlate = acpi_dma_xlate; | |
195 | adma->data = data; | |
196 | ||
ee8209fd AS |
197 | acpi_dma_parse_csrt(adev, adma); |
198 | ||
1b2e98bc AS |
199 | /* Now queue acpi_dma controller structure in list */ |
200 | mutex_lock(&acpi_dma_lock); | |
201 | list_add_tail(&adma->dma_controllers, &acpi_dma_list); | |
202 | mutex_unlock(&acpi_dma_lock); | |
203 | ||
204 | return 0; | |
205 | } | |
206 | EXPORT_SYMBOL_GPL(acpi_dma_controller_register); | |
207 | ||
208 | /** | |
209 | * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list | |
210 | * @dev: struct device of DMA controller | |
211 | * | |
212 | * Memory allocated by acpi_dma_controller_register() is freed here. | |
39d14478 AS |
213 | * |
214 | * Return: | |
215 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
216 | */ |
217 | int acpi_dma_controller_free(struct device *dev) | |
218 | { | |
219 | struct acpi_dma *adma; | |
220 | ||
221 | if (!dev) | |
222 | return -EINVAL; | |
223 | ||
224 | mutex_lock(&acpi_dma_lock); | |
225 | ||
226 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) | |
227 | if (adma->dev == dev) { | |
228 | list_del(&adma->dma_controllers); | |
229 | mutex_unlock(&acpi_dma_lock); | |
230 | kfree(adma); | |
231 | return 0; | |
232 | } | |
233 | ||
234 | mutex_unlock(&acpi_dma_lock); | |
235 | return -ENODEV; | |
236 | } | |
237 | EXPORT_SYMBOL_GPL(acpi_dma_controller_free); | |
238 | ||
239 | static void devm_acpi_dma_release(struct device *dev, void *res) | |
240 | { | |
241 | acpi_dma_controller_free(dev); | |
242 | } | |
243 | ||
244 | /** | |
245 | * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register() | |
246 | * @dev: device that is registering this DMA controller | |
247 | * @acpi_dma_xlate: translation function | |
4b8584ba | 248 | * @data: pointer to controller specific data |
1b2e98bc AS |
249 | * |
250 | * Managed acpi_dma_controller_register(). DMA controller registered by this | |
251 | * function are automatically freed on driver detach. See | |
252 | * acpi_dma_controller_register() for more information. | |
39d14478 AS |
253 | * |
254 | * Return: | |
255 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
256 | */ |
257 | int devm_acpi_dma_controller_register(struct device *dev, | |
258 | struct dma_chan *(*acpi_dma_xlate) | |
259 | (struct acpi_dma_spec *, struct acpi_dma *), | |
260 | void *data) | |
261 | { | |
262 | void *res; | |
263 | int ret; | |
264 | ||
265 | res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL); | |
266 | if (!res) | |
267 | return -ENOMEM; | |
268 | ||
269 | ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data); | |
270 | if (ret) { | |
271 | devres_free(res); | |
272 | return ret; | |
273 | } | |
274 | devres_add(dev, res); | |
275 | return 0; | |
276 | } | |
277 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register); | |
278 | ||
279 | /** | |
280 | * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free() | |
4b8584ba | 281 | * @dev: device that is unregistering as DMA controller |
1b2e98bc AS |
282 | * |
283 | * Unregister a DMA controller registered with | |
284 | * devm_acpi_dma_controller_register(). Normally this function will not need to | |
285 | * be called and the resource management code will ensure that the resource is | |
286 | * freed. | |
287 | */ | |
288 | void devm_acpi_dma_controller_free(struct device *dev) | |
289 | { | |
8f012583 | 290 | WARN_ON(devres_release(dev, devm_acpi_dma_release, NULL, NULL)); |
1b2e98bc AS |
291 | } |
292 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); | |
293 | ||
ee8209fd AS |
294 | /** |
295 | * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function | |
296 | * @adma: struct acpi_dma of DMA controller | |
297 | * @dma_spec: dma specifier to update | |
298 | * | |
ee8209fd AS |
299 | * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource |
300 | * Descriptor": | |
301 | * DMA Request Line bits is a platform-relative number uniquely | |
302 | * identifying the request line assigned. Request line-to-Controller | |
303 | * mapping is done in a controller-specific OS driver. | |
304 | * That's why we can safely adjust slave_id when the appropriate controller is | |
305 | * found. | |
39d14478 AS |
306 | * |
307 | * Return: | |
308 | * 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. | |
ee8209fd AS |
309 | */ |
310 | static int acpi_dma_update_dma_spec(struct acpi_dma *adma, | |
311 | struct acpi_dma_spec *dma_spec) | |
312 | { | |
313 | /* Set link to the DMA controller device */ | |
314 | dma_spec->dev = adma->dev; | |
315 | ||
316 | /* Check if the request line range is available */ | |
317 | if (adma->base_request_line == 0 && adma->end_request_line == 0) | |
318 | return 0; | |
319 | ||
320 | /* Check if slave_id falls to the range */ | |
321 | if (dma_spec->slave_id < adma->base_request_line || | |
322 | dma_spec->slave_id > adma->end_request_line) | |
323 | return -1; | |
324 | ||
325 | /* | |
326 | * Here we adjust slave_id. It should be a relative number to the base | |
327 | * request line. | |
328 | */ | |
329 | dma_spec->slave_id -= adma->base_request_line; | |
330 | ||
331 | return 1; | |
332 | } | |
333 | ||
1b2e98bc AS |
334 | struct acpi_dma_parser_data { |
335 | struct acpi_dma_spec dma_spec; | |
336 | size_t index; | |
337 | size_t n; | |
338 | }; | |
339 | ||
340 | /** | |
341 | * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier | |
342 | * @res: struct acpi_resource to get FixedDMA resources from | |
343 | * @data: pointer to a helper struct acpi_dma_parser_data | |
344 | */ | |
345 | static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) | |
346 | { | |
347 | struct acpi_dma_parser_data *pdata = data; | |
348 | ||
349 | if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) { | |
350 | struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma; | |
351 | ||
352 | if (pdata->n++ == pdata->index) { | |
353 | pdata->dma_spec.chan_id = dma->channels; | |
354 | pdata->dma_spec.slave_id = dma->request_lines; | |
355 | } | |
356 | } | |
357 | ||
358 | /* Tell the ACPI core to skip this resource */ | |
359 | return 1; | |
360 | } | |
361 | ||
362 | /** | |
363 | * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel | |
364 | * @dev: struct device to get DMA request from | |
365 | * @index: index of FixedDMA descriptor for @dev | |
366 | * | |
39d14478 | 367 | * Return: |
0f6a928d | 368 | * Pointer to appropriate dma channel on success or an error pointer. |
1b2e98bc AS |
369 | */ |
370 | struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, | |
371 | size_t index) | |
372 | { | |
373 | struct acpi_dma_parser_data pdata; | |
374 | struct acpi_dma_spec *dma_spec = &pdata.dma_spec; | |
6915ef1c | 375 | struct acpi_device *adev = ACPI_COMPANION(dev); |
1b2e98bc | 376 | struct list_head resource_list; |
1b2e98bc AS |
377 | struct acpi_dma *adma; |
378 | struct dma_chan *chan = NULL; | |
ee8209fd | 379 | int found; |
6915ef1c | 380 | int ret; |
1b2e98bc AS |
381 | |
382 | memset(&pdata, 0, sizeof(pdata)); | |
383 | pdata.index = index; | |
384 | ||
385 | /* Initial values for the request line and channel */ | |
386 | dma_spec->chan_id = -1; | |
387 | dma_spec->slave_id = -1; | |
388 | ||
389 | INIT_LIST_HEAD(&resource_list); | |
6915ef1c AS |
390 | ret = acpi_dev_get_resources(adev, &resource_list, |
391 | acpi_dma_parse_fixed_dma, &pdata); | |
1b2e98bc | 392 | acpi_dev_free_resource_list(&resource_list); |
6915ef1c AS |
393 | if (ret < 0) |
394 | return ERR_PTR(ret); | |
1b2e98bc AS |
395 | |
396 | if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) | |
0f6a928d | 397 | return ERR_PTR(-ENODEV); |
1b2e98bc AS |
398 | |
399 | mutex_lock(&acpi_dma_lock); | |
400 | ||
401 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) { | |
ee8209fd AS |
402 | /* |
403 | * We are not going to call translation function if slave_id | |
404 | * doesn't fall to the request range. | |
405 | */ | |
406 | found = acpi_dma_update_dma_spec(adma, dma_spec); | |
407 | if (found < 0) | |
408 | continue; | |
1b2e98bc | 409 | chan = adma->acpi_dma_xlate(dma_spec, adma); |
ee8209fd AS |
410 | /* |
411 | * Try to get a channel only from the DMA controller that | |
412 | * matches the slave_id. See acpi_dma_update_dma_spec() | |
413 | * description for the details. | |
414 | */ | |
415 | if (found > 0 || chan) | |
1b2e98bc AS |
416 | break; |
417 | } | |
418 | ||
419 | mutex_unlock(&acpi_dma_lock); | |
0f6a928d | 420 | return chan ? chan : ERR_PTR(-EPROBE_DEFER); |
1b2e98bc AS |
421 | } |
422 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); | |
423 | ||
424 | /** | |
425 | * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel | |
426 | * @dev: struct device to get DMA request from | |
427 | * @name: represents corresponding FixedDMA descriptor for @dev | |
428 | * | |
429 | * In order to support both Device Tree and ACPI in a single driver we | |
430 | * translate the names "tx" and "rx" here based on the most common case where | |
431 | * the first FixedDMA descriptor is TX and second is RX. | |
432 | * | |
3f4232ee MW |
433 | * If the device has "dma-names" property the FixedDMA descriptor indices |
434 | * are retrieved based on those. Otherwise the function falls back using | |
435 | * hardcoded indices. | |
436 | * | |
39d14478 | 437 | * Return: |
0f6a928d | 438 | * Pointer to appropriate dma channel on success or an error pointer. |
1b2e98bc AS |
439 | */ |
440 | struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, | |
441 | const char *name) | |
442 | { | |
3f4232ee MW |
443 | int index; |
444 | ||
445 | index = device_property_match_string(dev, "dma-names", name); | |
446 | if (index < 0) { | |
447 | if (!strcmp(name, "tx")) | |
448 | index = 0; | |
449 | else if (!strcmp(name, "rx")) | |
450 | index = 1; | |
451 | else | |
452 | return ERR_PTR(-ENODEV); | |
453 | } | |
1b2e98bc | 454 | |
36bf8fc4 | 455 | dev_dbg(dev, "Looking for DMA channel \"%s\" at index %d...\n", name, index); |
1b2e98bc AS |
456 | return acpi_dma_request_slave_chan_by_index(dev, index); |
457 | } | |
458 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name); | |
459 | ||
460 | /** | |
461 | * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper | |
462 | * @dma_spec: pointer to ACPI DMA specifier | |
463 | * @adma: pointer to ACPI DMA controller data | |
464 | * | |
465 | * A simple translation function for ACPI based devices. Passes &struct | |
39d14478 AS |
466 | * dma_spec to the DMA controller driver provided filter function. |
467 | * | |
468 | * Return: | |
469 | * Pointer to the channel if found or %NULL otherwise. | |
1b2e98bc AS |
470 | */ |
471 | struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, | |
472 | struct acpi_dma *adma) | |
473 | { | |
474 | struct acpi_dma_filter_info *info = adma->data; | |
475 | ||
476 | if (!info || !info->filter_fn) | |
477 | return NULL; | |
478 | ||
479 | return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec); | |
480 | } | |
481 | EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate); |