pcm_dmaengine.c 11 KB

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  1. /*
  2. * Copyright (C) 2012, Analog Devices Inc.
  3. * Author: Lars-Peter Clausen <lars@metafoo.de>
  4. *
  5. * Based on:
  6. * imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
  7. * mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
  8. * ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
  9. * Copyright (C) 2006 Applied Data Systems
  10. *
  11. * This program is free software; you can redistribute it and/or modify it
  12. * under the terms of the GNU General Public License as published by the
  13. * Free Software Foundation; either version 2 of the License, or (at your
  14. * option) any later version.
  15. *
  16. * You should have received a copy of the GNU General Public License along
  17. * with this program; if not, write to the Free Software Foundation, Inc.,
  18. * 675 Mass Ave, Cambridge, MA 02139, USA.
  19. *
  20. */
  21. #include <linux/module.h>
  22. #include <linux/init.h>
  23. #include <linux/dmaengine.h>
  24. #include <linux/slab.h>
  25. #include <sound/pcm.h>
  26. #include <sound/pcm_params.h>
  27. #include <sound/soc.h>
  28. #include <sound/dmaengine_pcm.h>
  29. struct dmaengine_pcm_runtime_data {
  30. struct dma_chan *dma_chan;
  31. dma_cookie_t cookie;
  32. unsigned int pos;
  33. };
  34. static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
  35. const struct snd_pcm_substream *substream)
  36. {
  37. return substream->runtime->private_data;
  38. }
  39. struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
  40. {
  41. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  42. return prtd->dma_chan;
  43. }
  44. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
  45. /**
  46. * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
  47. * @substream: PCM substream
  48. * @params: hw_params
  49. * @slave_config: DMA slave config
  50. *
  51. * This function can be used to initialize a dma_slave_config from a substream
  52. * and hw_params in a dmaengine based PCM driver implementation.
  53. */
  54. int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  55. const struct snd_pcm_hw_params *params,
  56. struct dma_slave_config *slave_config)
  57. {
  58. enum dma_slave_buswidth buswidth;
  59. switch (params_format(params)) {
  60. case SNDRV_PCM_FORMAT_S8:
  61. buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
  62. break;
  63. case SNDRV_PCM_FORMAT_S16_LE:
  64. buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
  65. break;
  66. case SNDRV_PCM_FORMAT_S18_3LE:
  67. case SNDRV_PCM_FORMAT_S20_3LE:
  68. case SNDRV_PCM_FORMAT_S24_LE:
  69. case SNDRV_PCM_FORMAT_S32_LE:
  70. buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
  71. break;
  72. default:
  73. return -EINVAL;
  74. }
  75. if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  76. slave_config->direction = DMA_MEM_TO_DEV;
  77. slave_config->dst_addr_width = buswidth;
  78. } else {
  79. slave_config->direction = DMA_DEV_TO_MEM;
  80. slave_config->src_addr_width = buswidth;
  81. }
  82. slave_config->device_fc = false;
  83. return 0;
  84. }
  85. EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
  86. /**
  87. * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
  88. * using DAI DMA data.
  89. * @substream: PCM substream
  90. * @dma_data: DAI DMA data
  91. * @slave_config: DMA slave configuration
  92. *
  93. * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
  94. * slave_id fields of the DMA slave config from the same fields of the DAI DMA
  95. * data struct. The src and dst fields will be initialized depending on the
  96. * direction of the substream. If the substream is a playback stream the dst
  97. * fields will be initialized, if it is a capture stream the src fields will be
  98. * initialized. The {dst,src}_addr_width field will only be initialized if the
  99. * addr_width field of the DAI DMA data struct is not equal to
  100. * DMA_SLAVE_BUSWIDTH_UNDEFINED.
  101. */
  102. void snd_dmaengine_pcm_set_config_from_dai_data(
  103. const struct snd_pcm_substream *substream,
  104. const struct snd_dmaengine_dai_dma_data *dma_data,
  105. struct dma_slave_config *slave_config)
  106. {
  107. if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  108. slave_config->dst_addr = dma_data->addr;
  109. slave_config->dst_maxburst = dma_data->maxburst;
  110. if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
  111. slave_config->dst_addr_width = dma_data->addr_width;
  112. } else {
  113. slave_config->src_addr = dma_data->addr;
  114. slave_config->src_maxburst = dma_data->maxburst;
  115. if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
  116. slave_config->src_addr_width = dma_data->addr_width;
  117. }
  118. slave_config->slave_id = dma_data->slave_id;
  119. }
  120. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
  121. static void dmaengine_pcm_dma_complete(void *arg)
  122. {
  123. struct snd_pcm_substream *substream = arg;
  124. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  125. prtd->pos += snd_pcm_lib_period_bytes(substream);
  126. if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
  127. prtd->pos = 0;
  128. snd_pcm_period_elapsed(substream);
  129. }
  130. static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
  131. {
  132. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  133. struct dma_chan *chan = prtd->dma_chan;
  134. struct dma_async_tx_descriptor *desc;
  135. enum dma_transfer_direction direction;
  136. unsigned long flags = DMA_CTRL_ACK;
  137. direction = snd_pcm_substream_to_dma_direction(substream);
  138. if (!substream->runtime->no_period_wakeup)
  139. flags |= DMA_PREP_INTERRUPT;
  140. prtd->pos = 0;
  141. desc = dmaengine_prep_dma_cyclic(chan,
  142. substream->runtime->dma_addr,
  143. snd_pcm_lib_buffer_bytes(substream),
  144. snd_pcm_lib_period_bytes(substream), direction, flags);
  145. if (!desc)
  146. return -ENOMEM;
  147. desc->callback = dmaengine_pcm_dma_complete;
  148. desc->callback_param = substream;
  149. prtd->cookie = dmaengine_submit(desc);
  150. return 0;
  151. }
  152. /**
  153. * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
  154. * @substream: PCM substream
  155. * @cmd: Trigger command
  156. *
  157. * Returns 0 on success, a negative error code otherwise.
  158. *
  159. * This function can be used as the PCM trigger callback for dmaengine based PCM
  160. * driver implementations.
  161. */
  162. int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
  163. {
  164. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  165. int ret;
  166. switch (cmd) {
  167. case SNDRV_PCM_TRIGGER_START:
  168. ret = dmaengine_pcm_prepare_and_submit(substream);
  169. if (ret)
  170. return ret;
  171. dma_async_issue_pending(prtd->dma_chan);
  172. break;
  173. case SNDRV_PCM_TRIGGER_RESUME:
  174. case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  175. dmaengine_resume(prtd->dma_chan);
  176. break;
  177. case SNDRV_PCM_TRIGGER_SUSPEND:
  178. case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  179. dmaengine_pause(prtd->dma_chan);
  180. break;
  181. case SNDRV_PCM_TRIGGER_STOP:
  182. dmaengine_terminate_all(prtd->dma_chan);
  183. break;
  184. default:
  185. return -EINVAL;
  186. }
  187. return 0;
  188. }
  189. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
  190. /**
  191. * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
  192. * @substream: PCM substream
  193. *
  194. * This function is deprecated and should not be used by new drivers, as its
  195. * results may be unreliable.
  196. */
  197. snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
  198. {
  199. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  200. return bytes_to_frames(substream->runtime, prtd->pos);
  201. }
  202. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
  203. /**
  204. * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
  205. * @substream: PCM substream
  206. *
  207. * This function can be used as the PCM pointer callback for dmaengine based PCM
  208. * driver implementations.
  209. */
  210. snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
  211. {
  212. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  213. struct dma_tx_state state;
  214. enum dma_status status;
  215. unsigned int buf_size;
  216. unsigned int pos = 0;
  217. status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
  218. if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
  219. buf_size = snd_pcm_lib_buffer_bytes(substream);
  220. if (state.residue > 0 && state.residue <= buf_size)
  221. pos = buf_size - state.residue;
  222. }
  223. return bytes_to_frames(substream->runtime, pos);
  224. }
  225. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
  226. /**
  227. * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
  228. * @filter_fn: Filter function used to request the DMA channel
  229. * @filter_data: Data passed to the DMA filter function
  230. *
  231. * Returns NULL or the requested DMA channel.
  232. *
  233. * This function request a DMA channel for usage with dmaengine PCM.
  234. */
  235. struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
  236. void *filter_data)
  237. {
  238. dma_cap_mask_t mask;
  239. dma_cap_zero(mask);
  240. dma_cap_set(DMA_SLAVE, mask);
  241. dma_cap_set(DMA_CYCLIC, mask);
  242. return dma_request_channel(mask, filter_fn, filter_data);
  243. }
  244. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
  245. /**
  246. * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
  247. * @substream: PCM substream
  248. * @chan: DMA channel to use for data transfers
  249. *
  250. * Returns 0 on success, a negative error code otherwise.
  251. *
  252. * The function should usually be called from the pcm open callback. Note that
  253. * this function will use private_data field of the substream's runtime. So it
  254. * is not availabe to your pcm driver implementation.
  255. */
  256. int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
  257. struct dma_chan *chan)
  258. {
  259. struct dmaengine_pcm_runtime_data *prtd;
  260. int ret;
  261. if (!chan)
  262. return -ENXIO;
  263. ret = snd_pcm_hw_constraint_integer(substream->runtime,
  264. SNDRV_PCM_HW_PARAM_PERIODS);
  265. if (ret < 0)
  266. return ret;
  267. prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
  268. if (!prtd)
  269. return -ENOMEM;
  270. prtd->dma_chan = chan;
  271. substream->runtime->private_data = prtd;
  272. return 0;
  273. }
  274. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
  275. /**
  276. * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
  277. * @substream: PCM substream
  278. * @filter_fn: Filter function used to request the DMA channel
  279. * @filter_data: Data passed to the DMA filter function
  280. *
  281. * Returns 0 on success, a negative error code otherwise.
  282. *
  283. * This function will request a DMA channel using the passed filter function and
  284. * data. The function should usually be called from the pcm open callback. Note
  285. * that this function will use private_data field of the substream's runtime. So
  286. * it is not availabe to your pcm driver implementation.
  287. */
  288. int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
  289. dma_filter_fn filter_fn, void *filter_data)
  290. {
  291. return snd_dmaengine_pcm_open(substream,
  292. snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
  293. }
  294. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
  295. /**
  296. * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
  297. * @substream: PCM substream
  298. */
  299. int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
  300. {
  301. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  302. kfree(prtd);
  303. return 0;
  304. }
  305. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
  306. /**
  307. * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
  308. * @substream: PCM substream
  309. *
  310. * Releases the DMA channel associated with the PCM substream.
  311. */
  312. int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
  313. {
  314. struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
  315. dma_release_channel(prtd->dma_chan);
  316. return snd_dmaengine_pcm_close(substream);
  317. }
  318. EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
  319. MODULE_LICENSE("GPL");