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12#include <linux/device.h>
13#include <linux/dma-mapping.h>
14#include <linux/err.h>
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/list.h>
18#include <linux/mutex.h>
19#include <linux/slab.h>
20#include <linux/ioport.h>
21#include <linux/acpi.h>
22#include <linux/acpi_dma.h>
23#include <linux/property.h>
24
25static LIST_HEAD(acpi_dma_list);
26static DEFINE_MUTEX(acpi_dma_lock);
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41static 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;
46 struct resource_entry *rentry;
47 resource_size_t mem = 0, irq = 0;
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) {
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;
63 }
64
65 acpi_dev_free_resource_list(&resource_list);
66
67
68 if (mem == 0 && irq == 0)
69 return 0;
70
71 si = (const struct acpi_csrt_shared_info *)&grp[1];
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73
74 if (si->mmio_base_low != lower_32_bits(mem) ||
75 si->mmio_base_high != upper_32_bits(mem) ||
76 si->gsi_interrupt != irq)
77 return 0;
78
79 dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",
80 (char *)&grp->vendor_id, grp->device_id, grp->revision);
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83 if (si->base_request_line == 0 && si->num_handshake_signals == 0)
84 return 0;
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87 ret = dma_coerce_mask_and_coherent(&adev->dev,
88 DMA_BIT_MASK(si->dma_address_width));
89 if (ret)
90 return 0;
91
92 adma->base_request_line = si->base_request_line;
93 adma->end_request_line = si->base_request_line +
94 si->num_handshake_signals - 1;
95
96 dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n",
97 adma->base_request_line, adma->end_request_line);
98
99 return 1;
100}
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115static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma)
116{
117 struct acpi_csrt_group *grp, *end;
118 struct acpi_table_csrt *csrt;
119 acpi_status status;
120 int ret;
121
122 status = acpi_get_table(ACPI_SIG_CSRT, 0,
123 (struct acpi_table_header **)&csrt);
124 if (ACPI_FAILURE(status)) {
125 if (status != AE_NOT_FOUND)
126 dev_warn(&adev->dev, "failed to get the CSRT table\n");
127 return;
128 }
129
130 grp = (struct acpi_csrt_group *)(csrt + 1);
131 end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);
132
133 while (grp < end) {
134 ret = acpi_dma_parse_resource_group(grp, adev, adma);
135 if (ret < 0) {
136 dev_warn(&adev->dev,
137 "error in parsing resource group\n");
138 break;
139 }
140
141 grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
142 }
143
144 acpi_put_table((struct acpi_table_header *)csrt);
145}
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161int acpi_dma_controller_register(struct device *dev,
162 struct dma_chan *(*acpi_dma_xlate)
163 (struct acpi_dma_spec *, struct acpi_dma *),
164 void *data)
165{
166 struct acpi_device *adev;
167 struct acpi_dma *adma;
168
169 if (!dev || !acpi_dma_xlate)
170 return -EINVAL;
171
172
173 adev = ACPI_COMPANION(dev);
174 if (!adev)
175 return -EINVAL;
176
177 adma = kzalloc(sizeof(*adma), GFP_KERNEL);
178 if (!adma)
179 return -ENOMEM;
180
181 adma->dev = dev;
182 adma->acpi_dma_xlate = acpi_dma_xlate;
183 adma->data = data;
184
185 acpi_dma_parse_csrt(adev, adma);
186
187
188 mutex_lock(&acpi_dma_lock);
189 list_add_tail(&adma->dma_controllers, &acpi_dma_list);
190 mutex_unlock(&acpi_dma_lock);
191
192 return 0;
193}
194EXPORT_SYMBOL_GPL(acpi_dma_controller_register);
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205int acpi_dma_controller_free(struct device *dev)
206{
207 struct acpi_dma *adma;
208
209 if (!dev)
210 return -EINVAL;
211
212 mutex_lock(&acpi_dma_lock);
213
214 list_for_each_entry(adma, &acpi_dma_list, dma_controllers)
215 if (adma->dev == dev) {
216 list_del(&adma->dma_controllers);
217 mutex_unlock(&acpi_dma_lock);
218 kfree(adma);
219 return 0;
220 }
221
222 mutex_unlock(&acpi_dma_lock);
223 return -ENODEV;
224}
225EXPORT_SYMBOL_GPL(acpi_dma_controller_free);
226
227static void devm_acpi_dma_release(struct device *dev, void *res)
228{
229 acpi_dma_controller_free(dev);
230}
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245int devm_acpi_dma_controller_register(struct device *dev,
246 struct dma_chan *(*acpi_dma_xlate)
247 (struct acpi_dma_spec *, struct acpi_dma *),
248 void *data)
249{
250 void *res;
251 int ret;
252
253 res = devres_alloc(devm_acpi_dma_release, 0, GFP_KERNEL);
254 if (!res)
255 return -ENOMEM;
256
257 ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data);
258 if (ret) {
259 devres_free(res);
260 return ret;
261 }
262 devres_add(dev, res);
263 return 0;
264}
265EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register);
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276void devm_acpi_dma_controller_free(struct device *dev)
277{
278 WARN_ON(devres_release(dev, devm_acpi_dma_release, NULL, NULL));
279}
280EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free);
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298static int acpi_dma_update_dma_spec(struct acpi_dma *adma,
299 struct acpi_dma_spec *dma_spec)
300{
301
302 dma_spec->dev = adma->dev;
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305 if (adma->base_request_line == 0 && adma->end_request_line == 0)
306 return 0;
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309 if (dma_spec->slave_id < adma->base_request_line ||
310 dma_spec->slave_id > adma->end_request_line)
311 return -1;
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317 dma_spec->slave_id -= adma->base_request_line;
318
319 return 1;
320}
321
322struct acpi_dma_parser_data {
323 struct acpi_dma_spec dma_spec;
324 size_t index;
325 size_t n;
326};
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333static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data)
334{
335 struct acpi_dma_parser_data *pdata = data;
336
337 if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) {
338 struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma;
339
340 if (pdata->n++ == pdata->index) {
341 pdata->dma_spec.chan_id = dma->channels;
342 pdata->dma_spec.slave_id = dma->request_lines;
343 }
344 }
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347 return 1;
348}
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358struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
359 size_t index)
360{
361 struct acpi_dma_parser_data pdata;
362 struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
363 struct acpi_device *adev = ACPI_COMPANION(dev);
364 struct list_head resource_list;
365 struct acpi_dma *adma;
366 struct dma_chan *chan = NULL;
367 int found;
368 int ret;
369
370 memset(&pdata, 0, sizeof(pdata));
371 pdata.index = index;
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373
374 dma_spec->chan_id = -1;
375 dma_spec->slave_id = -1;
376
377 INIT_LIST_HEAD(&resource_list);
378 ret = acpi_dev_get_resources(adev, &resource_list,
379 acpi_dma_parse_fixed_dma, &pdata);
380 acpi_dev_free_resource_list(&resource_list);
381 if (ret < 0)
382 return ERR_PTR(ret);
383
384 if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
385 return ERR_PTR(-ENODEV);
386
387 mutex_lock(&acpi_dma_lock);
388
389 list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
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394 found = acpi_dma_update_dma_spec(adma, dma_spec);
395 if (found < 0)
396 continue;
397 chan = adma->acpi_dma_xlate(dma_spec, adma);
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403 if (found > 0 || chan)
404 break;
405 }
406
407 mutex_unlock(&acpi_dma_lock);
408 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
409}
410EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
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428struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
429 const char *name)
430{
431 int index;
432
433 index = device_property_match_string(dev, "dma-names", name);
434 if (index < 0) {
435 if (!strcmp(name, "tx"))
436 index = 0;
437 else if (!strcmp(name, "rx"))
438 index = 1;
439 else
440 return ERR_PTR(-ENODEV);
441 }
442
443 dev_dbg(dev, "Looking for DMA channel \"%s\" at index %d...\n", name, index);
444 return acpi_dma_request_slave_chan_by_index(dev, index);
445}
446EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name);
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459struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
460 struct acpi_dma *adma)
461{
462 struct acpi_dma_filter_info *info = adma->data;
463
464 if (!info || !info->filter_fn)
465 return NULL;
466
467 return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);
468}
469EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate);
470