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>
diff --git a/arch/sh/boards/mach-hp6xx/setup.c b/arch/sh/boards/mach-hp6xx/setup.c
index 8f305b3..e6dd5e9 100644
--- a/arch/sh/boards/mach-hp6xx/setup.c
+++ b/arch/sh/boards/mach-hp6xx/setup.c
@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/irq.h>
+#include <sound/sh_dac_audio.h>
 #include <asm/hd64461.h>
 #include <asm/io.h>
 #include <mach/hp6xx.h>
@@ -51,9 +52,63 @@
 	.id		= -1,
 };
 
+static void dac_audio_start(struct dac_audio_pdata *pdata)
+{
+	u16 v;
+	u8 v8;
+
+	/* HP Jornada 680/690 speaker on */
+	v = inw(HD64461_GPADR);
+	v &= ~HD64461_GPADR_SPEAKER;
+	outw(v, HD64461_GPADR);
+
+	/* HP Palmtop 620lx/660lx speaker on */
+	v8 = inb(PKDR);
+	v8 &= ~PKDR_SPEAKER;
+	outb(v8, PKDR);
+
+	sh_dac_enable(pdata->channel);
+}
+
+static void dac_audio_stop(struct dac_audio_pdata *pdata)
+{
+	u16 v;
+	u8 v8;
+
+	/* HP Jornada 680/690 speaker off */
+	v = inw(HD64461_GPADR);
+	v |= HD64461_GPADR_SPEAKER;
+	outw(v, HD64461_GPADR);
+
+	/* HP Palmtop 620lx/660lx speaker off */
+	v8 = inb(PKDR);
+	v8 |= PKDR_SPEAKER;
+	outb(v8, PKDR);
+
+	sh_dac_output(0, pdata->channel);
+	sh_dac_disable(pdata->channel);
+}
+
+static struct dac_audio_pdata dac_audio_platform_data = {
+	.buffer_size		= 64000,
+	.channel		= 1,
+	.start			= dac_audio_start,
+	.stop			= dac_audio_stop,
+};
+
+static struct platform_device dac_audio_device = {
+	.name		= "dac_audio",
+	.id		= -1,
+	.dev		= {
+		.platform_data	= &dac_audio_platform_data,
+	}
+
+};
+
 static struct platform_device *hp6xx_devices[] __initdata = {
 	&cf_ide_device,
 	&jornadakbd_device,
+	&dac_audio_device,
 };
 
 static void __init hp6xx_init_irq(void)