Initial version of tinyalsa
From git://github.com/tinyalsa/tinyalsa.git 193b1c3b
Change-Id: I8971581d4867bd785ac628638679d2c09c79169f
diff --git a/pcm.c b/pcm.c
new file mode 100644
index 0000000..1fab6f4
--- /dev/null
+++ b/pcm.c
@@ -0,0 +1,350 @@
+/* pcm.c
+**
+** Copyright 2011, The Android Open Source Project
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are met:
+** * Redistributions of source code must retain the above copyright
+** notice, this list of conditions and the following disclaimer.
+** * Redistributions in binary form must reproduce the above copyright
+** notice, this list of conditions and the following disclaimer in the
+** documentation and/or other materials provided with the distribution.
+** * Neither the name of The Android Open Source Project nor the names of
+** its contributors may be used to endorse or promote products derived
+** from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND
+** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE
+** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+** DAMAGE.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+
+#include <linux/ioctl.h>
+#define __force
+#define __bitwise
+#define __user
+#include <sound/asound.h>
+
+#include <tinyalsa/asoundlib.h>
+
+#define PARAM_MAX SNDRV_PCM_HW_PARAM_LAST_INTERVAL
+
+static inline int param_is_mask(int p)
+{
+ return (p >= SNDRV_PCM_HW_PARAM_FIRST_MASK) &&
+ (p <= SNDRV_PCM_HW_PARAM_LAST_MASK);
+}
+
+static inline int param_is_interval(int p)
+{
+ return (p >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL) &&
+ (p <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL);
+}
+
+static inline struct snd_interval *param_to_interval(struct snd_pcm_hw_params *p, int n)
+{
+ return &(p->intervals[n - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL]);
+}
+
+static inline struct snd_mask *param_to_mask(struct snd_pcm_hw_params *p, int n)
+{
+ return &(p->masks[n - SNDRV_PCM_HW_PARAM_FIRST_MASK]);
+}
+
+static void param_set_mask(struct snd_pcm_hw_params *p, int n, unsigned int bit)
+{
+ if (bit >= SNDRV_MASK_MAX)
+ return;
+ if (param_is_mask(n)) {
+ struct snd_mask *m = param_to_mask(p, n);
+ m->bits[0] = 0;
+ m->bits[1] = 0;
+ m->bits[bit >> 5] |= (1 << (bit & 31));
+ }
+}
+
+static void param_set_min(struct snd_pcm_hw_params *p, int n, unsigned int val)
+{
+ if (param_is_interval(n)) {
+ struct snd_interval *i = param_to_interval(p, n);
+ i->min = val;
+ }
+}
+
+static void param_set_max(struct snd_pcm_hw_params *p, int n, unsigned int val)
+{
+ if (param_is_interval(n)) {
+ struct snd_interval *i = param_to_interval(p, n);
+ i->max = val;
+ }
+}
+
+static void param_set_int(struct snd_pcm_hw_params *p, int n, unsigned int val)
+{
+ if (param_is_interval(n)) {
+ struct snd_interval *i = param_to_interval(p, n);
+ i->min = val;
+ i->max = val;
+ i->integer = 1;
+ }
+}
+
+static void param_init(struct snd_pcm_hw_params *p)
+{
+ int n;
+
+ memset(p, 0, sizeof(*p));
+ for (n = SNDRV_PCM_HW_PARAM_FIRST_MASK;
+ n <= SNDRV_PCM_HW_PARAM_LAST_MASK; n++) {
+ struct snd_mask *m = param_to_mask(p, n);
+ m->bits[0] = ~0;
+ m->bits[1] = ~0;
+ }
+ for (n = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL;
+ n <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; n++) {
+ struct snd_interval *i = param_to_interval(p, n);
+ i->min = 0;
+ i->max = ~0;
+ }
+}
+
+#define PCM_ERROR_MAX 128
+
+struct pcm {
+ int fd;
+ unsigned int flags;
+ int running:1;
+ int underruns;
+ unsigned int buffer_size;
+ char error[PCM_ERROR_MAX];
+ struct pcm_config config;
+};
+
+unsigned int pcm_get_buffer_size(struct pcm *pcm)
+{
+ return pcm->buffer_size;
+}
+
+const char* pcm_get_error(struct pcm *pcm)
+{
+ return pcm->error;
+}
+
+static int oops(struct pcm *pcm, int e, const char *fmt, ...)
+{
+ va_list ap;
+ int sz;
+
+ va_start(ap, fmt);
+ vsnprintf(pcm->error, PCM_ERROR_MAX, fmt, ap);
+ va_end(ap);
+ sz = strlen(pcm->error);
+
+ if (errno)
+ snprintf(pcm->error + sz, PCM_ERROR_MAX - sz,
+ ": %s", strerror(e));
+ return -1;
+}
+
+int pcm_write(struct pcm *pcm, void *data, unsigned int count)
+{
+ struct snd_xferi x;
+
+ if (pcm->flags & PCM_IN)
+ return -EINVAL;
+
+ x.buf = data;
+ x.frames = count / (pcm->config.channels * 2); /* TODO: handle 32bit */
+
+ for (;;) {
+ if (!pcm->running) {
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE))
+ return oops(pcm, errno, "cannot prepare channel");
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x))
+ return oops(pcm, errno, "cannot write initial data");
+ pcm->running = 1;
+ return 0;
+ }
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_WRITEI_FRAMES, &x)) {
+ pcm->running = 0;
+ if (errno == EPIPE) {
+ /* we failed to make our window -- try to restart */
+ pcm->underruns++;
+ continue;
+ }
+ return oops(pcm, errno, "cannot write stream data");
+ }
+ return 0;
+ }
+}
+
+int pcm_read(struct pcm *pcm, void *data, unsigned int count)
+{
+ struct snd_xferi x;
+
+ if (!(pcm->flags & PCM_IN))
+ return -EINVAL;
+
+ x.buf = data;
+ x.frames = count / (pcm->config.channels * 2); /* TODO: handle 32bit */
+
+ for (;;) {
+ if (!pcm->running) {
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_PREPARE))
+ return oops(pcm, errno, "cannot prepare channel");
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_START))
+ return oops(pcm, errno, "cannot start channel");
+ pcm->running = 1;
+ }
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_READI_FRAMES, &x)) {
+ pcm->running = 0;
+ if (errno == EPIPE) {
+ /* we failed to make our window -- try to restart */
+ pcm->underruns++;
+ continue;
+ }
+ return oops(pcm, errno, "cannot read stream data");
+ }
+ return 0;
+ }
+}
+
+static struct pcm bad_pcm = {
+ .fd = -1,
+};
+
+int pcm_close(struct pcm *pcm)
+{
+ if (pcm == &bad_pcm)
+ return 0;
+
+ if (pcm->fd >= 0)
+ close(pcm->fd);
+ pcm->running = 0;
+ pcm->buffer_size = 0;
+ pcm->fd = -1;
+ return 0;
+}
+
+static unsigned int pcm_format_to_alsa(enum pcm_format format)
+{
+ switch (format) {
+ case PCM_FORMAT_S32_LE:
+ return SNDRV_PCM_FORMAT_S32_LE;
+ default:
+ case PCM_FORMAT_S16_LE:
+ return SNDRV_PCM_FORMAT_S16_LE;
+ };
+}
+
+static unsigned int pcm_format_to_bits(enum pcm_format format)
+{
+ switch (format) {
+ case PCM_FORMAT_S32_LE:
+ return 32;
+ default:
+ case PCM_FORMAT_S16_LE:
+ return 16;
+ };
+}
+
+struct pcm *pcm_open(unsigned int card, unsigned int device,
+ unsigned int flags, struct pcm_config *config)
+{
+ struct pcm *pcm;
+ struct snd_pcm_info info;
+ struct snd_pcm_hw_params params;
+ struct snd_pcm_sw_params sparams;
+ char fn[256];
+
+ pcm = calloc(1, sizeof(struct pcm));
+ if (!pcm || !config)
+ return &bad_pcm; /* TODO: could support default config here */
+
+ pcm->config = *config;
+
+ snprintf(fn, sizeof(fn), "/dev/snd/pcmC%uD%u%c", card, device,
+ flags & PCM_IN ? 'c' : 'p');
+
+ pcm->flags = flags;
+ pcm->fd = open(fn, O_RDWR);
+ if (pcm->fd < 0) {
+ oops(pcm, errno, "cannot open device '%s'", fn);
+ return pcm;
+ }
+
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_INFO, &info)) {
+ oops(pcm, errno, "cannot get info");
+ goto fail;
+ }
+
+ param_init(¶ms);
+ param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_ACCESS,
+ SNDRV_PCM_ACCESS_RW_INTERLEAVED);
+ param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_FORMAT,
+ pcm_format_to_alsa(config->format));
+ param_set_mask(¶ms, SNDRV_PCM_HW_PARAM_SUBFORMAT,
+ SNDRV_PCM_SUBFORMAT_STD);
+ param_set_min(¶ms, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, config->period_size);
+ param_set_int(¶ms, SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
+ pcm_format_to_bits(config->format));
+ param_set_int(¶ms, SNDRV_PCM_HW_PARAM_FRAME_BITS,
+ pcm_format_to_bits(config->format) * config->channels);
+ param_set_int(¶ms, SNDRV_PCM_HW_PARAM_CHANNELS,
+ config->channels);
+ param_set_int(¶ms, SNDRV_PCM_HW_PARAM_PERIODS, config->period_count);
+ param_set_int(¶ms, SNDRV_PCM_HW_PARAM_RATE, config->rate);
+
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_HW_PARAMS, ¶ms)) {
+ oops(pcm, errno, "cannot set hw params");
+ goto fail;
+ }
+
+ memset(&sparams, 0, sizeof(sparams));
+ sparams.tstamp_mode = SNDRV_PCM_TSTAMP_NONE;
+ sparams.period_step = 1;
+ sparams.avail_min = 1;
+ sparams.start_threshold = config->period_count * config->period_size;
+ sparams.stop_threshold = config->period_count * config->period_size;
+ sparams.xfer_align = config->period_size / 2; /* needed for old kernels */
+ sparams.silence_size = 0;
+ sparams.silence_threshold = 0;
+
+ if (ioctl(pcm->fd, SNDRV_PCM_IOCTL_SW_PARAMS, &sparams)) {
+ oops(pcm, errno, "cannot set sw params");
+ goto fail;
+ }
+
+ pcm->buffer_size = config->period_count * config->period_size;
+ pcm->underruns = 0;
+ return pcm;
+
+fail:
+ close(pcm->fd);
+ pcm->fd = -1;
+ return pcm;
+}
+
+int pcm_is_ready(struct pcm *pcm)
+{
+ return pcm->fd >= 0;
+}