ALSA: sh: add SuperH DAC audio driver for ALSA V4

This is a port of the sound/oss/sh_dac_audio.c driver.
The driver uses an on-chip 8-bit D/A converter, which has a speaker connected
to one of its channels, found in several ancient HP machines.
For interrupts it uses a high-resolution timer (hrtimer).
Tested on SH7709 based hp6xx (HP Jornada 680/690 and HP Palmtop 620lx/660lx).

Also, since OSS Emulation works, the old OSS sound/oss/sh_dac_audio.c driver
would be obsolete soon, and it could be removed.

Signed-off-by: Rafael Ignacio Zurita <rizurita@yahoo.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

3 files changed, 463 insertions, 0 deletions

diff --git a/sound/sh/Kconfig b/sound/sh/Kconfig
index aed0f90c3919..61139f3c1614 100644
--- a/sound/sh/Kconfig
+++ b/sound/sh/Kconfig
@@ -19,5 +19,13 @@ config SND_AICA
         help
           ALSA Sound driver for the SEGA Dreamcast console.
 
+config SND_SH_DAC_AUDIO
+        tristate "SuperH DAC audio support"
+        depends on SND
+        depends on CPU_SH3 && HIGH_RES_TIMERS
+        select SND_PCM
+        help
+          Say Y here to include support for the on-chip DAC.
+
 endif   # SND_SUPERH
 
diff --git a/sound/sh/Makefile b/sound/sh/Makefile
index 8fdcb6e26f00..7d09b5188cf7 100644
--- a/sound/sh/Makefile
+++ b/sound/sh/Makefile
@@ -3,6 +3,8 @@
 #
 
 snd-aica-objs := aica.o
+snd-sh_dac_audio-objs := sh_dac_audio.o
 
 # Toplevel Module Dependency
 obj-$(CONFIG_SND_AICA) += snd-aica.o
+obj-$(CONFIG_SND_SH_DAC_AUDIO) += snd-sh_dac_audio.o
diff --git a/sound/sh/sh_dac_audio.c b/sound/sh/sh_dac_audio.c
new file mode 100644
index 000000000000..76d9ad27d91c
--- /dev/null
+++ b/sound/sh/sh_dac_audio.c
@@ -0,0 +1,453 @@
+/*
+ * sh_dac_audio.c - SuperH DAC audio driver for ALSA
+ *
+ * Copyright (c) 2009 by Rafael Ignacio Zurita <rizurita@yahoo.com>
+ *
+ *
+ * Based on sh_dac_audio.c (Copyright (C) 2004, 2005 by Andriy Skulysh)
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/hrtimer.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/sh_dac_audio.h>
+#include <asm/clock.h>
+#include <asm/hd64461.h>
+#include <mach/hp6xx.h>
+#include <cpu/dac.h>
+
+MODULE_AUTHOR("Rafael Ignacio Zurita <rizurita@yahoo.com>");
+MODULE_DESCRIPTION("SuperH DAC audio driver");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("{{SuperH DAC audio support}}");
+
+/* Module Parameters */
+static int index = SNDRV_DEFAULT_IDX1;
+static char *id = SNDRV_DEFAULT_STR1;
+module_param(index, int, 0444);
+MODULE_PARM_DESC(index, "Index value for SuperH DAC audio.");
+module_param(id, charp, 0444);
+MODULE_PARM_DESC(id, "ID string for SuperH DAC audio.");
+
+/* main struct */
+struct snd_sh_dac {
+        struct snd_card *card;
+        struct snd_pcm_substream *substream;
+        struct hrtimer hrtimer;
+        ktime_t wakeups_per_second;
+
+        int rate;
+        int empty;
+        char *data_buffer, *buffer_begin, *buffer_end;
+        int processed; /* bytes proccesed, to compare with period_size */
+        int buffer_size;
+        struct dac_audio_pdata *pdata;
+};
+
+
+static void dac_audio_start_timer(struct snd_sh_dac *chip)
+{
+        hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
+                      HRTIMER_MODE_REL);
+}
+
+static void dac_audio_stop_timer(struct snd_sh_dac *chip)
+{
+        hrtimer_cancel(&chip->hrtimer);
+}
+
+static void dac_audio_reset(struct snd_sh_dac *chip)
+{
+        dac_audio_stop_timer(chip);
+        chip->buffer_begin = chip->buffer_end = chip->data_buffer;
+        chip->processed = 0;
+        chip->empty = 1;
+}
+
+static void dac_audio_set_rate(struct snd_sh_dac *chip)
+{
+        chip->wakeups_per_second = ktime_set(0, 1000000000 / chip->rate);
+}
+
+
+/* PCM INTERFACE */
+
+static struct snd_pcm_hardware snd_sh_dac_pcm_hw = {
+        .info                   = (SNDRV_PCM_INFO_MMAP |
+                                        SNDRV_PCM_INFO_MMAP_VALID |
+                                        SNDRV_PCM_INFO_INTERLEAVED |
+                                        SNDRV_PCM_INFO_HALF_DUPLEX),
+        .formats                = SNDRV_PCM_FMTBIT_U8,
+        .rates                  = SNDRV_PCM_RATE_8000,
+        .rate_min               = 8000,
+        .rate_max               = 8000,
+        .channels_min           = 1,
+        .channels_max           = 1,
+        .buffer_bytes_max       = (48*1024),
+        .period_bytes_min       = 1,
+        .period_bytes_max       = (48*1024),
+        .periods_min            = 1,
+        .periods_max            = 1024,
+};
+
+static int snd_sh_dac_pcm_open(struct snd_pcm_substream *substream)
+{
+        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
+        struct snd_pcm_runtime *runtime = substream->runtime;
+
+        runtime->hw = snd_sh_dac_pcm_hw;
+
+        chip->substream = substream;
+        chip->buffer_begin = chip->buffer_end = chip->data_buffer;
+        chip->processed = 0;
+        chip->empty = 1;
+
+        chip->pdata->start(chip->pdata);
+
+        return 0;
+}
+
+static int snd_sh_dac_pcm_close(struct snd_pcm_substream *substream)
+{
+        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
+
+        chip->substream = NULL;
+
+        dac_audio_stop_timer(chip);
+        chip->pdata->stop(chip->pdata);
+
+        return 0;
+}
+
+static int snd_sh_dac_pcm_hw_params(struct snd_pcm_substream *substream,
+                                struct snd_pcm_hw_params *hw_params)
+{
+        return snd_pcm_lib_malloc_pages(substream,
+                        params_buffer_bytes(hw_params));
+}
+
+static int snd_sh_dac_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+        return snd_pcm_lib_free_pages(substream);
+}
+
+static int snd_sh_dac_pcm_prepare(struct snd_pcm_substream *substream)
+{
+        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
+        struct snd_pcm_runtime *runtime = chip->substream->runtime;
+
+        chip->buffer_size = runtime->buffer_size;
+        memset(chip->data_buffer, 0, chip->pdata->buffer_size);
+
+        return 0;
+}
+
+static int snd_sh_dac_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
+
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+                dac_audio_start_timer(chip);
+                break;
+        case SNDRV_PCM_TRIGGER_STOP:
+                chip->buffer_begin = chip->buffer_end = chip->data_buffer;
+                chip->processed = 0;
+                chip->empty = 1;
+                dac_audio_stop_timer(chip);
+                break;
+        default:
+                 return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int snd_sh_dac_pcm_copy(struct snd_pcm_substream *substream, int channel,
+        snd_pcm_uframes_t pos, void __user *src, snd_pcm_uframes_t count)
+{
+        /* channel is not used (interleaved data) */
+        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        ssize_t b_count = frames_to_bytes(runtime , count);
+        ssize_t b_pos = frames_to_bytes(runtime , pos);
+
+        if (count < 0)
+                return -EINVAL;
+
+        if (!count)
+                return 0;
+
+        memcpy_toio(chip->data_buffer + b_pos, src, b_count);
+        chip->buffer_end = chip->data_buffer + b_pos + b_count;
+
+        if (chip->empty) {
+                chip->empty = 0;
+                dac_audio_start_timer(chip);
+        }
+
+        return 0;
+}
+
+static int snd_sh_dac_pcm_silence(struct snd_pcm_substream *substream,
+                                  int channel, snd_pcm_uframes_t pos,
+                                  snd_pcm_uframes_t count)
+{
+        /* channel is not used (interleaved data) */
+        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        ssize_t b_count = frames_to_bytes(runtime , count);
+        ssize_t b_pos = frames_to_bytes(runtime , pos);
+
+        if (count < 0)
+                return -EINVAL;
+
+        if (!count)
+                return 0;
+
+        memset_io(chip->data_buffer + b_pos, 0, b_count);
+        chip->buffer_end = chip->data_buffer + b_pos + b_count;
+
+        if (chip->empty) {
+                chip->empty = 0;
+                dac_audio_start_timer(chip);
+        }
+
+        return 0;
+}
+
+static
+snd_pcm_uframes_t snd_sh_dac_pcm_pointer(struct snd_pcm_substream *substream)
+{
+        struct snd_sh_dac *chip = snd_pcm_substream_chip(substream);
+        int pointer = chip->buffer_begin - chip->data_buffer;
+
+        return pointer;
+}
+
+/* pcm ops */
+static struct snd_pcm_ops snd_sh_dac_pcm_ops = {
+        .open           = snd_sh_dac_pcm_open,
+        .close          = snd_sh_dac_pcm_close,
+        .ioctl          = snd_pcm_lib_ioctl,
+        .hw_params      = snd_sh_dac_pcm_hw_params,
+        .hw_free        = snd_sh_dac_pcm_hw_free,
+        .prepare        = snd_sh_dac_pcm_prepare,
+        .trigger        = snd_sh_dac_pcm_trigger,
+        .pointer        = snd_sh_dac_pcm_pointer,
+        .copy           = snd_sh_dac_pcm_copy,
+        .silence        = snd_sh_dac_pcm_silence,
+        .mmap           = snd_pcm_lib_mmap_iomem,
+};
+
+static int __devinit snd_sh_dac_pcm(struct snd_sh_dac *chip, int device)
+{
+        int err;
+        struct snd_pcm *pcm;
+
+        /* device should be always 0 for us */
+        err = snd_pcm_new(chip->card, "SH_DAC PCM", device, 1, 0, &pcm);
+        if (err < 0)
+                return err;
+
+        pcm->private_data = chip;
+        strcpy(pcm->name, "SH_DAC PCM");
+        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_sh_dac_pcm_ops);
+
+        /* buffer size=48K */
+        snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
+                                          snd_dma_continuous_data(GFP_KERNEL),
+                                                        48 * 1024,
+                                                        48 * 1024);
+
+        return 0;
+}
+/* END OF PCM INTERFACE */
+
+
+/* driver .remove  --  destructor */
+static int snd_sh_dac_remove(struct platform_device *devptr)
+{
+        snd_card_free(platform_get_drvdata(devptr));
+        platform_set_drvdata(devptr, NULL);
+
+        return 0;
+}
+
+/* free -- it has been defined by create */
+static int snd_sh_dac_free(struct snd_sh_dac *chip)
+{
+        /* release the data */
+        kfree(chip->data_buffer);
+        kfree(chip);
+
+        return 0;
+}
+
+static int snd_sh_dac_dev_free(struct snd_device *device)
+{
+        struct snd_sh_dac *chip = device->device_data;
+
+        return snd_sh_dac_free(chip);
+}
+
+static enum hrtimer_restart sh_dac_audio_timer(struct hrtimer *handle)
+{
+        struct snd_sh_dac *chip = container_of(handle, struct snd_sh_dac,
+                                               hrtimer);
+        struct snd_pcm_runtime *runtime = chip->substream->runtime;
+        ssize_t b_ps = frames_to_bytes(runtime, runtime->period_size);
+
+        if (!chip->empty) {
+                sh_dac_output(*chip->buffer_begin, chip->pdata->channel);
+                chip->buffer_begin++;
+
+                chip->processed++;
+                if (chip->processed >= b_ps) {
+                        chip->processed -= b_ps;
+                        snd_pcm_period_elapsed(chip->substream);
+                }
+
+                if (chip->buffer_begin == (chip->data_buffer +
+                                           chip->buffer_size - 1))
+                        chip->buffer_begin = chip->data_buffer;
+
+                if (chip->buffer_begin == chip->buffer_end)
+                        chip->empty = 1;
+
+        }
+
+        if (!chip->empty)
+                hrtimer_start(&chip->hrtimer, chip->wakeups_per_second,
+                              HRTIMER_MODE_REL);
+
+        return HRTIMER_NORESTART;
+}
+
+/* create  --  chip-specific constructor for the cards components */
+static int __devinit snd_sh_dac_create(struct snd_card *card,
+                                       struct platform_device *devptr,
+                                       struct snd_sh_dac **rchip)
+{
+        struct snd_sh_dac *chip;
+        int err;
+
+        static struct snd_device_ops ops = {
+                   .dev_free = snd_sh_dac_dev_free,
+        };
+
+        *rchip = NULL;
+
+        chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+        if (chip == NULL)
+                return -ENOMEM;
+
+        chip->card = card;
+
+        hrtimer_init(&chip->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        chip->hrtimer.function = sh_dac_audio_timer;
+
+        dac_audio_reset(chip);
+        chip->rate = 8000;
+        dac_audio_set_rate(chip);
+
+        chip->pdata = devptr->dev.platform_data;
+
+        chip->data_buffer = kmalloc(chip->pdata->buffer_size, GFP_KERNEL);
+        if (chip->data_buffer == NULL) {
+                kfree(chip);
+                return -ENOMEM;
+        }
+
+        err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops);
+        if (err < 0) {
+                snd_sh_dac_free(chip);
+                return err;
+        }
+
+        *rchip = chip;
+
+        return 0;
+}
+
+/* driver .probe  --  constructor */
+static int __devinit snd_sh_dac_probe(struct platform_device *devptr)
+{
+        struct snd_sh_dac *chip;
+        struct snd_card *card;
+        int err;
+
+        err = snd_card_create(index, id, THIS_MODULE, 0, &card);
+        if (err < 0) {
+                        snd_printk(KERN_ERR "cannot allocate the card\n");
+                        return err;
+        }
+
+        err = snd_sh_dac_create(card, devptr, &chip);
+        if (err < 0)
+                goto probe_error;
+
+        err = snd_sh_dac_pcm(chip, 0);
+        if (err < 0)
+                goto probe_error;
+
+        strcpy(card->driver, "snd_sh_dac");
+        strcpy(card->shortname, "SuperH DAC audio driver");
+        printk(KERN_INFO "%s %s", card->longname, card->shortname);
+
+        err = snd_card_register(card);
+        if (err < 0)
+                goto probe_error;
+
+        snd_printk("ALSA driver for SuperH DAC audio");
+
+        platform_set_drvdata(devptr, card);
+        return 0;
+
+probe_error:
+        snd_card_free(card);
+        return err;
+}
+
+/*
+ * "driver" definition
+ */
+static struct platform_driver driver = {
+        .probe  = snd_sh_dac_probe,
+        .remove = snd_sh_dac_remove,
+        .driver = {
+                .name = "dac_audio",
+        },
+};
+
+static int __init sh_dac_init(void)
+{
+        return platform_driver_register(&driver);
+}
+
+static void __exit sh_dac_exit(void)
+{
+        platform_driver_unregister(&driver);
+}
+
+module_init(sh_dac_init);
+module_exit(sh_dac_exit);