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>

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 @@ static struct platform_device jornadakbd_device = {
 	.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)

arch/sh/include/mach-common/mach/hp6xx.h

@@ -29,6 +29,9 @@
 
 #define PKDR_LED_GREEN		0x10
 
+/* HP Palmtop 620lx/660lx speaker on/off */
+#define PKDR_SPEAKER		0x20
+
 #define SCPDR_TS_SCAN_ENABLE	0x20
 #define SCPDR_TS_SCAN_Y		0x02
 #define SCPDR_TS_SCAN_X		0x01
@@ -42,6 +45,7 @@
 #define ADC_CHANNEL_BACKUP	4
 #define ADC_CHANNEL_CHARGE	5
 
+/* HP Jornada 680/690 speaker on/off */
 #define HD64461_GPADR_SPEAKER	0x01
 #define HD64461_GPADR_PCMCIA0	(0x02|0x08)
 

include/sound/sh_dac_audio.h

+/*
+ * SH_DAC specific configuration, for the dac_audio platform_device
+ *
+ * Copyright (C) 2009 Rafael Ignacio Zurita <rizurita@yahoo.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#ifndef __INCLUDE_SH_DAC_AUDIO_H
+#define __INCLUDE_SH_DAC_AUDIO_H
+
+struct dac_audio_pdata {
+	int buffer_size;
+	int channel;
+	void (*start)(struct dac_audio_pdata *pd);
+	void (*stop)(struct dac_audio_pdata *pd);
+};
+
+#endif /* __INCLUDE_SH_DAC_AUDIO_H */

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
 

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