1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * sh_dac_audio.c - SuperH DAC audio driver for ALSA
5 * Copyright (c) 2009 by Rafael Ignacio Zurita <rizurita@yahoo.com>
7 * Based on sh_dac_audio.c (Copyright (C) 2004, 2005 by Andriy Skulysh)
10 #include <linux/hrtimer.h>
11 #include <linux/interrupt.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <sound/core.h>
17 #include <sound/initval.h>
18 #include <sound/pcm.h>
19 #include <sound/sh_dac_audio.h>
20 #include <asm/clock.h>
21 #include <asm/hd64461.h>
22 #include <mach/hp6xx.h>
25 MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
26 MODULE_DESCRIPTION("SuperH DAC audio driver");
27 MODULE_LICENSE("GPL");
28 MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
30 /* Module Parameters */
31 static int index = SNDRV_DEFAULT_IDX1;
32 static char *id = SNDRV_DEFAULT_STR1;
33 module_param(index, int, 0444);
34 MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
35 module_param(id, charp, 0444);
36 MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
40 struct snd_card *card;
41 struct snd_pcm_substream *substream;
42 struct hrtimer hrtimer;
43 ktime_t wakeups_per_second;
47 char *data_buffer, *buffer_begin, *buffer_end;
48 int processed; /* bytes proccesed, to compare with period_size */
50 struct dac_audio_pdata *pdata;
54 static void dac_audio_start_timer(struct snd_sh_dac *chip)
56 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
60 static void dac_audio_stop_timer(struct snd_sh_dac *chip)
62 hrtimer_cancel(&chip->hrtimer);
65 static void dac_audio_reset(struct snd_sh_dac *chip)
67 dac_audio_stop_timer(chip);
68 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
73 static void dac_audio_set_rate(struct snd_sh_dac *chip)
75 chip->wakeups_per_second = 1000000000 / chip->rate;
81 static const struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
82 .info = (SNDRV_PCM_INFO_MMAP |
83 SNDRV_PCM_INFO_MMAP_VALID |
84 SNDRV_PCM_INFO_INTERLEAVED |
85 SNDRV_PCM_INFO_HALF_DUPLEX),
86 .formats = SNDRV_PCM_FMTBIT_U8,
87 .rates = SNDRV_PCM_RATE_8000,
92 .buffer_bytes_max = (48*1024),
93 .period_bytes_min = 1,
94 .period_bytes_max = (48*1024),
99 static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
101 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
102 struct snd_pcm_runtime *runtime = substream->runtime;
104 runtime->hw = snd_sh_dac_pcm_hw;
106 chip->substream = substream;
107 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
111 chip->pdata->start(chip->pdata);
116 static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
118 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
120 chip->substream = NULL;
122 dac_audio_stop_timer(chip);
123 chip->pdata->stop(chip->pdata);
128 static int snd_sh_dac_pcm_hw_params(struct snd_pcm_substream *substream,
129 struct snd_pcm_hw_params *hw_params)
131 return snd_pcm_lib_malloc_pages(substream,
132 params_buffer_bytes(hw_params));
135 static int snd_sh_dac_pcm_hw_free(struct snd_pcm_substream *substream)
137 return snd_pcm_lib_free_pages(substream);
140 static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
142 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
143 struct snd_pcm_runtime *runtime = chip->substream->runtime;
145 chip->buffer_size = runtime->buffer_size;
146 memset(chip->data_buffer, 0, chip->pdata->buffer_size);
151 static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
153 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
156 case SNDRV_PCM_TRIGGER_START:
157 dac_audio_start_timer(chip);
159 case SNDRV_PCM_TRIGGER_STOP:
160 chip->buffer_begin = chip->buffer_end = chip->data_buffer;
163 dac_audio_stop_timer(chip);
172 static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream,
173 int channel, unsigned long pos,
174 void __user *src, unsigned long count)
176 /* channel is not used (interleaved data) */
177 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
178 struct snd_pcm_runtime *runtime = substream->runtime;
180 if (copy_from_user_toio(chip->data_buffer + pos, src, count))
182 chip->buffer_end = chip->data_buffer + pos + count;
186 dac_audio_start_timer(chip);
192 static int snd_sh_dac_pcm_copy_kernel(struct snd_pcm_substream *substream,
193 int channel, unsigned long pos,
194 void *src, unsigned long count)
196 /* channel is not used (interleaved data) */
197 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
198 struct snd_pcm_runtime *runtime = substream->runtime;
200 memcpy_toio(chip->data_buffer + pos, src, count);
201 chip->buffer_end = chip->data_buffer + pos + count;
205 dac_audio_start_timer(chip);
211 static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
212 int channel, unsigned long pos,
215 /* channel is not used (interleaved data) */
216 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
217 struct snd_pcm_runtime *runtime = substream->runtime;
219 memset_io(chip->data_buffer + pos, 0, count);
220 chip->buffer_end = chip->data_buffer + pos + count;
224 dac_audio_start_timer(chip);
231 snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
233 struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
234 int pointer = chip->buffer_begin - chip->data_buffer;
240 static const struct snd_pcm_ops snd_sh_dac_pcm_ops = {
241 .open = snd_sh_dac_pcm_open,
242 .close = snd_sh_dac_pcm_close,
243 .ioctl = snd_pcm_lib_ioctl,
244 .hw_params = snd_sh_dac_pcm_hw_params,
245 .hw_free = snd_sh_dac_pcm_hw_free,
246 .prepare = snd_sh_dac_pcm_prepare,
247 .trigger = snd_sh_dac_pcm_trigger,
248 .pointer = snd_sh_dac_pcm_pointer,
249 .copy_user = snd_sh_dac_pcm_copy,
250 .copy_kernel = snd_sh_dac_pcm_copy_kernel,
251 .fill_silence = snd_sh_dac_pcm_silence,
252 .mmap = snd_pcm_lib_mmap_iomem,
255 static int snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
260 /* device should be always 0 for us */
261 err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
265 pcm->private_data = chip;
266 strcpy(pcm->name, "SH_DAC PCM");
267 snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
269 /* buffer size=48K */
270 snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
277 /* END OF PCM INTERFACE */
280 /* driver .remove -- destructor */
281 static int snd_sh_dac_remove(struct platform_device *devptr)
283 snd_card_free(platform_get_drvdata(devptr));
287 /* free -- it has been defined by create */
288 static int snd_sh_dac_free(struct snd_sh_dac *chip)
290 /* release the data */
291 kfree(chip->data_buffer);
297 static int snd_sh_dac_dev_free(struct snd_device *device)
299 struct snd_sh_dac *chip = device->device_data;
301 return snd_sh_dac_free(chip);
304 static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
306 struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
308 struct snd_pcm_runtime *runtime = chip->substream->runtime;
309 ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
312 sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
313 chip->buffer_begin++;
316 if (chip->processed >= b_ps) {
317 chip->processed -= b_ps;
318 snd_pcm_period_elapsed(chip->substream);
321 if (chip->buffer_begin == (chip->data_buffer +
322 chip->buffer_size - 1))
323 chip->buffer_begin = chip->data_buffer;
325 if (chip->buffer_begin == chip->buffer_end)
331 hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
334 return HRTIMER_NORESTART;
337 /* create -- chip-specific constructor for the cards components */
338 static int snd_sh_dac_create(struct snd_card *card,
339 struct platform_device *devptr,
340 struct snd_sh_dac **rchip)
342 struct snd_sh_dac *chip;
345 static struct snd_device_ops ops = {
346 .dev_free = snd_sh_dac_dev_free,
351 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
357 hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
358 chip->hrtimer.function = sh_dac_audio_timer;
360 dac_audio_reset(chip);
362 dac_audio_set_rate(chip);
364 chip->pdata = devptr->dev.platform_data;
366 chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
367 if (chip->data_buffer == NULL) {
372 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
374 snd_sh_dac_free(chip);
383 /* driver .probe -- constructor */
384 static int snd_sh_dac_probe(struct platform_device *devptr)
386 struct snd_sh_dac *chip;
387 struct snd_card *card;
390 err = snd_card_new(&devptr->dev, index, id, THIS_MODULE, 0, &card);
392 snd_printk(KERN_ERR "cannot allocate the card\n");
396 err = snd_sh_dac_create(card, devptr, &chip);
400 err = snd_sh_dac_pcm(chip, 0);
404 strcpy(card->driver, "snd_sh_dac");
405 strcpy(card->shortname, "SuperH DAC audio driver");
406 printk(KERN_INFO "%s %s", card->longname, card->shortname);
408 err = snd_card_register(card);
412 snd_printk(KERN_INFO "ALSA driver for SuperH DAC audio");
414 platform_set_drvdata(devptr, card);
423 * "driver" definition
425 static struct platform_driver sh_dac_driver = {
426 .probe = snd_sh_dac_probe,
427 .remove = snd_sh_dac_remove,
433 module_platform_driver(sh_dac_driver);