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> | |
0f6a928d | 13 | #include <linux/err.h> |
1b2e98bc | 14 | #include <linux/module.h> |
f94cf9f4 | 15 | #include <linux/kernel.h> |
1b2e98bc AS |
16 | #include <linux/list.h> |
17 | #include <linux/mutex.h> | |
18 | #include <linux/slab.h> | |
ee8209fd | 19 | #include <linux/ioport.h> |
1b2e98bc AS |
20 | #include <linux/acpi.h> |
21 | #include <linux/acpi_dma.h> | |
3f4232ee | 22 | #include <linux/property.h> |
1b2e98bc AS |
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 | * | |
ee8209fd AS |
33 | * In order to match a device from DSDT table to the corresponding CSRT device |
34 | * we use MMIO address and IRQ. | |
39d14478 AS |
35 | * |
36 | * Return: | |
37 | * 1 on success, 0 when no information is available, or appropriate errno value | |
38 | * on error. | |
ee8209fd AS |
39 | */ |
40 | static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, | |
41 | struct acpi_device *adev, struct acpi_dma *adma) | |
42 | { | |
43 | const struct acpi_csrt_shared_info *si; | |
44 | struct list_head resource_list; | |
90e97820 | 45 | struct resource_entry *rentry; |
ee8209fd | 46 | resource_size_t mem = 0, irq = 0; |
ee8209fd AS |
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) { | |
90e97820 JL |
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; | |
ee8209fd AS |
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 */ | |
f94cf9f4 AS |
73 | if (si->mmio_base_low != lower_32_bits(mem) || |
74 | si->mmio_base_high != upper_32_bits(mem) || | |
75 | si->gsi_interrupt != irq) | |
ee8209fd AS |
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 */ | |
aff1e0ce JN |
164 | adev = ACPI_COMPANION(dev); |
165 | if (!adev) | |
1b2e98bc AS |
166 | return -EINVAL; |
167 | ||
168 | adma = kzalloc(sizeof(*adma), GFP_KERNEL); | |
169 | if (!adma) | |
170 | return -ENOMEM; | |
171 | ||
172 | adma->dev = dev; | |
173 | adma->acpi_dma_xlate = acpi_dma_xlate; | |
174 | adma->data = data; | |
175 | ||
ee8209fd AS |
176 | acpi_dma_parse_csrt(adev, adma); |
177 | ||
1b2e98bc AS |
178 | /* Now queue acpi_dma controller structure in list */ |
179 | mutex_lock(&acpi_dma_lock); | |
180 | list_add_tail(&adma->dma_controllers, &acpi_dma_list); | |
181 | mutex_unlock(&acpi_dma_lock); | |
182 | ||
183 | return 0; | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(acpi_dma_controller_register); | |
186 | ||
187 | /** | |
188 | * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list | |
189 | * @dev: struct device of DMA controller | |
190 | * | |
191 | * Memory allocated by acpi_dma_controller_register() is freed here. | |
39d14478 AS |
192 | * |
193 | * Return: | |
194 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
195 | */ |
196 | int acpi_dma_controller_free(struct device *dev) | |
197 | { | |
198 | struct acpi_dma *adma; | |
199 | ||
200 | if (!dev) | |
201 | return -EINVAL; | |
202 | ||
203 | mutex_lock(&acpi_dma_lock); | |
204 | ||
205 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) | |
206 | if (adma->dev == dev) { | |
207 | list_del(&adma->dma_controllers); | |
208 | mutex_unlock(&acpi_dma_lock); | |
209 | kfree(adma); | |
210 | return 0; | |
211 | } | |
212 | ||
213 | mutex_unlock(&acpi_dma_lock); | |
214 | return -ENODEV; | |
215 | } | |
216 | EXPORT_SYMBOL_GPL(acpi_dma_controller_free); | |
217 | ||
218 | static void devm_acpi_dma_release(struct device *dev, void *res) | |
219 | { | |
220 | acpi_dma_controller_free(dev); | |
221 | } | |
222 | ||
223 | /** | |
224 | * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register() | |
225 | * @dev: device that is registering this DMA controller | |
226 | * @acpi_dma_xlate: translation function | |
227 | * @data pointer to controller specific data | |
228 | * | |
229 | * Managed acpi_dma_controller_register(). DMA controller registered by this | |
230 | * function are automatically freed on driver detach. See | |
231 | * acpi_dma_controller_register() for more information. | |
39d14478 AS |
232 | * |
233 | * Return: | |
234 | * 0 on success or appropriate errno value on error. | |
1b2e98bc AS |
235 | */ |
236 | int devm_acpi_dma_controller_register(struct device *dev, | |
237 | struct dma_chan *(*acpi_dma_xlate) | |
238 | (struct acpi_dma_spec *, struct acpi_dma *), | |
239 | void *data) | |
240 | { | |
241 | void *res; | |
242 | int ret; | |
243 | ||
244 | res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL); | |
245 | if (!res) | |
246 | return -ENOMEM; | |
247 | ||
248 | ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data); | |
249 | if (ret) { | |
250 | devres_free(res); | |
251 | return ret; | |
252 | } | |
253 | devres_add(dev, res); | |
254 | return 0; | |
255 | } | |
256 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register); | |
257 | ||
258 | /** | |
259 | * devm_acpi_dma_controller_free - resource managed acpi_dma_controller_free() | |
260 | * | |
261 | * Unregister a DMA controller registered with | |
262 | * devm_acpi_dma_controller_register(). Normally this function will not need to | |
263 | * be called and the resource management code will ensure that the resource is | |
264 | * freed. | |
265 | */ | |
266 | void devm_acpi_dma_controller_free(struct device *dev) | |
267 | { | |
8f012583 | 268 | WARN_ON(devres_release(dev, devm_acpi_dma_release, NULL, NULL)); |
1b2e98bc AS |
269 | } |
270 | EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); | |
271 | ||
ee8209fd AS |
272 | /** |
273 | * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function | |
274 | * @adma: struct acpi_dma of DMA controller | |
275 | * @dma_spec: dma specifier to update | |
276 | * | |
ee8209fd AS |
277 | * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource |
278 | * Descriptor": | |
279 | * DMA Request Line bits is a platform-relative number uniquely | |
280 | * identifying the request line assigned. Request line-to-Controller | |
281 | * mapping is done in a controller-specific OS driver. | |
282 | * That's why we can safely adjust slave_id when the appropriate controller is | |
283 | * found. | |
39d14478 AS |
284 | * |
285 | * Return: | |
286 | * 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. | |
ee8209fd AS |
287 | */ |
288 | static int acpi_dma_update_dma_spec(struct acpi_dma *adma, | |
289 | struct acpi_dma_spec *dma_spec) | |
290 | { | |
291 | /* Set link to the DMA controller device */ | |
292 | dma_spec->dev = adma->dev; | |
293 | ||
294 | /* Check if the request line range is available */ | |
295 | if (adma->base_request_line == 0 && adma->end_request_line == 0) | |
296 | return 0; | |
297 | ||
298 | /* Check if slave_id falls to the range */ | |
299 | if (dma_spec->slave_id < adma->base_request_line || | |
300 | dma_spec->slave_id > adma->end_request_line) | |
301 | return -1; | |
302 | ||
303 | /* | |
304 | * Here we adjust slave_id. It should be a relative number to the base | |
305 | * request line. | |
306 | */ | |
307 | dma_spec->slave_id -= adma->base_request_line; | |
308 | ||
309 | return 1; | |
310 | } | |
311 | ||
1b2e98bc AS |
312 | struct acpi_dma_parser_data { |
313 | struct acpi_dma_spec dma_spec; | |
314 | size_t index; | |
315 | size_t n; | |
316 | }; | |
317 | ||
318 | /** | |
319 | * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier | |
320 | * @res: struct acpi_resource to get FixedDMA resources from | |
321 | * @data: pointer to a helper struct acpi_dma_parser_data | |
322 | */ | |
323 | static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) | |
324 | { | |
325 | struct acpi_dma_parser_data *pdata = data; | |
326 | ||
327 | if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) { | |
328 | struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma; | |
329 | ||
330 | if (pdata->n++ == pdata->index) { | |
331 | pdata->dma_spec.chan_id = dma->channels; | |
332 | pdata->dma_spec.slave_id = dma->request_lines; | |
333 | } | |
334 | } | |
335 | ||
336 | /* Tell the ACPI core to skip this resource */ | |
337 | return 1; | |
338 | } | |
339 | ||
340 | /** | |
341 | * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel | |
342 | * @dev: struct device to get DMA request from | |
343 | * @index: index of FixedDMA descriptor for @dev | |
344 | * | |
39d14478 | 345 | * Return: |
0f6a928d | 346 | * Pointer to appropriate dma channel on success or an error pointer. |
1b2e98bc AS |
347 | */ |
348 | struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, | |
349 | size_t index) | |
350 | { | |
351 | struct acpi_dma_parser_data pdata; | |
352 | struct acpi_dma_spec *dma_spec = &pdata.dma_spec; | |
353 | struct list_head resource_list; | |
354 | struct acpi_device *adev; | |
355 | struct acpi_dma *adma; | |
356 | struct dma_chan *chan = NULL; | |
ee8209fd | 357 | int found; |
1b2e98bc AS |
358 | |
359 | /* Check if the device was enumerated by ACPI */ | |
aff1e0ce | 360 | if (!dev) |
0f6a928d | 361 | return ERR_PTR(-ENODEV); |
1b2e98bc | 362 | |
aff1e0ce JN |
363 | adev = ACPI_COMPANION(dev); |
364 | if (!adev) | |
0f6a928d | 365 | return ERR_PTR(-ENODEV); |
1b2e98bc AS |
366 | |
367 | memset(&pdata, 0, sizeof(pdata)); | |
368 | pdata.index = index; | |
369 | ||
370 | /* Initial values for the request line and channel */ | |
371 | dma_spec->chan_id = -1; | |
372 | dma_spec->slave_id = -1; | |
373 | ||
374 | INIT_LIST_HEAD(&resource_list); | |
375 | acpi_dev_get_resources(adev, &resource_list, | |
376 | acpi_dma_parse_fixed_dma, &pdata); | |
377 | acpi_dev_free_resource_list(&resource_list); | |
378 | ||
379 | if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) | |
0f6a928d | 380 | return ERR_PTR(-ENODEV); |
1b2e98bc AS |
381 | |
382 | mutex_lock(&acpi_dma_lock); | |
383 | ||
384 | list_for_each_entry(adma, &acpi_dma_list, dma_controllers) { | |
ee8209fd AS |
385 | /* |
386 | * We are not going to call translation function if slave_id | |
387 | * doesn't fall to the request range. | |
388 | */ | |
389 | found = acpi_dma_update_dma_spec(adma, dma_spec); | |
390 | if (found < 0) | |
391 | continue; | |
1b2e98bc | 392 | chan = adma->acpi_dma_xlate(dma_spec, adma); |
ee8209fd AS |
393 | /* |
394 | * Try to get a channel only from the DMA controller that | |
395 | * matches the slave_id. See acpi_dma_update_dma_spec() | |
396 | * description for the details. | |
397 | */ | |
398 | if (found > 0 || chan) | |
1b2e98bc AS |
399 | break; |
400 | } | |
401 | ||
402 | mutex_unlock(&acpi_dma_lock); | |
0f6a928d | 403 | return chan ? chan : ERR_PTR(-EPROBE_DEFER); |
1b2e98bc AS |
404 | } |
405 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); | |
406 | ||
407 | /** | |
408 | * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel | |
409 | * @dev: struct device to get DMA request from | |
410 | * @name: represents corresponding FixedDMA descriptor for @dev | |
411 | * | |
412 | * In order to support both Device Tree and ACPI in a single driver we | |
413 | * translate the names "tx" and "rx" here based on the most common case where | |
414 | * the first FixedDMA descriptor is TX and second is RX. | |
415 | * | |
3f4232ee MW |
416 | * If the device has "dma-names" property the FixedDMA descriptor indices |
417 | * are retrieved based on those. Otherwise the function falls back using | |
418 | * hardcoded indices. | |
419 | * | |
39d14478 | 420 | * Return: |
0f6a928d | 421 | * Pointer to appropriate dma channel on success or an error pointer. |
1b2e98bc AS |
422 | */ |
423 | struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, | |
424 | const char *name) | |
425 | { | |
3f4232ee MW |
426 | int index; |
427 | ||
428 | index = device_property_match_string(dev, "dma-names", name); | |
429 | if (index < 0) { | |
430 | if (!strcmp(name, "tx")) | |
431 | index = 0; | |
432 | else if (!strcmp(name, "rx")) | |
433 | index = 1; | |
434 | else | |
435 | return ERR_PTR(-ENODEV); | |
436 | } | |
1b2e98bc | 437 | |
36bf8fc4 | 438 | dev_dbg(dev, "Looking for DMA channel \"%s\" at index %d...\n", name, index); |
1b2e98bc AS |
439 | return acpi_dma_request_slave_chan_by_index(dev, index); |
440 | } | |
441 | EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name); | |
442 | ||
443 | /** | |
444 | * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper | |
445 | * @dma_spec: pointer to ACPI DMA specifier | |
446 | * @adma: pointer to ACPI DMA controller data | |
447 | * | |
448 | * A simple translation function for ACPI based devices. Passes &struct | |
39d14478 AS |
449 | * dma_spec to the DMA controller driver provided filter function. |
450 | * | |
451 | * Return: | |
452 | * Pointer to the channel if found or %NULL otherwise. | |
1b2e98bc AS |
453 | */ |
454 | struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, | |
455 | struct acpi_dma *adma) | |
456 | { | |
457 | struct acpi_dma_filter_info *info = adma->data; | |
458 | ||
459 | if (!info || !info->filter_fn) | |
460 | return NULL; | |
461 | ||
462 | return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec); | |
463 | } | |
464 | EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate); |