blob: 1e506afa33f5e5a9b95753ce0e98ceb2f4ce7e66 [file] [log] [blame]
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +03001/*
2 * ACPI helpers for DMA request / controller
3 *
4 * Based on of-dma.c
5 *
6 * Copyright (C) 2013, Intel Corporation
Andy Shevchenkoee8209f2013-05-08 11:55:48 +03007 * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
8 * Mika Westerberg <mika.westerberg@linux.intel.com>
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +03009 *
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>
Andy Shevchenkoee8209f2013-05-08 11:55:48 +030020#include <linux/ioport.h>
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +030021#include <linux/acpi.h>
22#include <linux/acpi_dma.h>
23
24static LIST_HEAD(acpi_dma_list);
25static DEFINE_MUTEX(acpi_dma_lock);
26
27/**
Andy Shevchenkoee8209f2013-05-08 11:55:48 +030028 * 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 *
Andy Shevchenkoee8209f2013-05-08 11:55:48 +030033 * In order to match a device from DSDT table to the corresponding CSRT device
34 * we use MMIO address and IRQ.
Andy Shevchenko39d14472013-12-02 15:16:28 +020035 *
36 * Return:
37 * 1 on success, 0 when no information is available, or appropriate errno value
38 * on error.
Andy Shevchenkoee8209f2013-05-08 11:55:48 +030039 */
40static 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;
45 struct resource_list_entry *rentry;
46 resource_size_t mem = 0, irq = 0;
Andy Shevchenkoee8209f2013-05-08 11:55:48 +030047 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
Andy Shevchenkoee8209f2013-05-08 11:55:48 +030076 dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",
Andy Shevchenkob4d6d332013-08-21 14:27:06 +030077 (char *)&grp->vendor_id, grp->device_id, grp->revision);
Andy Shevchenkoee8209f2013-05-08 11:55:48 +030078
79 /* Check if the request line range is available */
80 if (si->base_request_line == 0 && si->num_handshake_signals == 0)
81 return 0;
82
83 adma->base_request_line = si->base_request_line;
84 adma->end_request_line = si->base_request_line +
85 si->num_handshake_signals - 1;
86
87 dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n",
88 adma->base_request_line, adma->end_request_line);
89
90 return 1;
91}
92
93/**
94 * acpi_dma_parse_csrt - parse CSRT to exctract additional DMA resources
95 * @adev: ACPI device to match with
96 * @adma: struct acpi_dma of the given DMA controller
97 *
98 * CSRT or Core System Resources Table is a proprietary ACPI table
99 * introduced by Microsoft. This table can contain devices that are not in
100 * the system DSDT table. In particular DMA controllers might be described
101 * here.
102 *
103 * We are using this table to get the request line range of the specific DMA
104 * controller to be used later.
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300105 */
106static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma)
107{
108 struct acpi_csrt_group *grp, *end;
109 struct acpi_table_csrt *csrt;
110 acpi_status status;
111 int ret;
112
113 status = acpi_get_table(ACPI_SIG_CSRT, 0,
114 (struct acpi_table_header **)&csrt);
115 if (ACPI_FAILURE(status)) {
116 if (status != AE_NOT_FOUND)
117 dev_warn(&adev->dev, "failed to get the CSRT table\n");
118 return;
119 }
120
121 grp = (struct acpi_csrt_group *)(csrt + 1);
122 end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);
123
124 while (grp < end) {
125 ret = acpi_dma_parse_resource_group(grp, adev, adma);
126 if (ret < 0) {
127 dev_warn(&adev->dev,
128 "error in parsing resource group\n");
129 return;
130 }
131
132 grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
133 }
134}
135
136/**
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300137 * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers
138 * @dev: struct device of DMA controller
139 * @acpi_dma_xlate: translation function which converts a dma specifier
140 * into a dma_chan structure
141 * @data pointer to controller specific data to be used by
142 * translation function
143 *
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300144 * Allocated memory should be freed with appropriate acpi_dma_controller_free()
145 * call.
Andy Shevchenko39d14472013-12-02 15:16:28 +0200146 *
147 * Return:
148 * 0 on success or appropriate errno value on error.
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300149 */
150int acpi_dma_controller_register(struct device *dev,
151 struct dma_chan *(*acpi_dma_xlate)
152 (struct acpi_dma_spec *, struct acpi_dma *),
153 void *data)
154{
155 struct acpi_device *adev;
156 struct acpi_dma *adma;
157
158 if (!dev || !acpi_dma_xlate)
159 return -EINVAL;
160
161 /* Check if the device was enumerated by ACPI */
162 if (!ACPI_HANDLE(dev))
163 return -EINVAL;
164
165 if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev))
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
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300176 acpi_dma_parse_csrt(adev, adma);
177
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300178 /* 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}
185EXPORT_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.
Andy Shevchenko39d14472013-12-02 15:16:28 +0200192 *
193 * Return:
194 * 0 on success or appropriate errno value on error.
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300195 */
196int 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}
216EXPORT_SYMBOL_GPL(acpi_dma_controller_free);
217
218static 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.
Andy Shevchenko39d14472013-12-02 15:16:28 +0200232 *
233 * Return:
234 * 0 on success or appropriate errno value on error.
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300235 */
236int 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}
256EXPORT_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 */
266void devm_acpi_dma_controller_free(struct device *dev)
267{
268 WARN_ON(devres_destroy(dev, devm_acpi_dma_release, NULL, NULL));
269}
270EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free);
271
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300272/**
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 *
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300277 * 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.
Andy Shevchenko39d14472013-12-02 15:16:28 +0200284 *
285 * Return:
286 * 0, if no information is avaiable, -1 on mismatch, and 1 otherwise.
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300287 */
288static 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
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300312struct 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 */
323static 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 *
Andy Shevchenko39d14472013-12-02 15:16:28 +0200345 * Return:
346 * Pointer to appropriate dma channel on success or NULL on error.
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300347 */
348struct 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;
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300357 int found;
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300358
359 /* Check if the device was enumerated by ACPI */
360 if (!dev || !ACPI_HANDLE(dev))
361 return NULL;
362
363 if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev))
364 return NULL;
365
366 memset(&pdata, 0, sizeof(pdata));
367 pdata.index = index;
368
369 /* Initial values for the request line and channel */
370 dma_spec->chan_id = -1;
371 dma_spec->slave_id = -1;
372
373 INIT_LIST_HEAD(&resource_list);
374 acpi_dev_get_resources(adev, &resource_list,
375 acpi_dma_parse_fixed_dma, &pdata);
376 acpi_dev_free_resource_list(&resource_list);
377
378 if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
379 return NULL;
380
381 mutex_lock(&acpi_dma_lock);
382
383 list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300384 /*
385 * We are not going to call translation function if slave_id
386 * doesn't fall to the request range.
387 */
388 found = acpi_dma_update_dma_spec(adma, dma_spec);
389 if (found < 0)
390 continue;
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300391 chan = adma->acpi_dma_xlate(dma_spec, adma);
Andy Shevchenkoee8209f2013-05-08 11:55:48 +0300392 /*
393 * Try to get a channel only from the DMA controller that
394 * matches the slave_id. See acpi_dma_update_dma_spec()
395 * description for the details.
396 */
397 if (found > 0 || chan)
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300398 break;
399 }
400
401 mutex_unlock(&acpi_dma_lock);
402 return chan;
403}
404EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
405
406/**
407 * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel
408 * @dev: struct device to get DMA request from
409 * @name: represents corresponding FixedDMA descriptor for @dev
410 *
411 * In order to support both Device Tree and ACPI in a single driver we
412 * translate the names "tx" and "rx" here based on the most common case where
413 * the first FixedDMA descriptor is TX and second is RX.
414 *
Andy Shevchenko39d14472013-12-02 15:16:28 +0200415 * Return:
416 * Pointer to appropriate dma channel on success or NULL on error.
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300417 */
418struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
419 const char *name)
420{
421 size_t index;
422
423 if (!strcmp(name, "tx"))
424 index = 0;
425 else if (!strcmp(name, "rx"))
426 index = 1;
427 else
428 return NULL;
429
430 return acpi_dma_request_slave_chan_by_index(dev, index);
431}
432EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name);
433
434/**
435 * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper
436 * @dma_spec: pointer to ACPI DMA specifier
437 * @adma: pointer to ACPI DMA controller data
438 *
439 * A simple translation function for ACPI based devices. Passes &struct
Andy Shevchenko39d14472013-12-02 15:16:28 +0200440 * dma_spec to the DMA controller driver provided filter function.
441 *
442 * Return:
443 * Pointer to the channel if found or %NULL otherwise.
Andy Shevchenko1b2e98b2013-04-09 14:05:43 +0300444 */
445struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
446 struct acpi_dma *adma)
447{
448 struct acpi_dma_filter_info *info = adma->data;
449
450 if (!info || !info->filter_fn)
451 return NULL;
452
453 return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);
454}
455EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate);