[PATCH] AC97 bus interface for ad-hoc drivers

[Liam Girdwood <liam.girdwood@wolfsonmicro.com>]

[-- Attachment #1: Type: text/plain, Size: 446 bytes --]

This patch adds support for ad-hoc AC97 device drivers (e.g WM97xx and
UCB touchscreen drivers) and was originally posted to the list by
Nicolas Pitre as an RFC. 

Changes from RFC version :-

  o Now matches codec name within codec group.
  o Added ac97_dev_release() to stop kernel complaining about no release
method for device.

Liam

Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Nicolas Pitre <nico@cam.org>


[-- Attachment #2: ac97-bus.diff --]
[-- Type: text/x-patch, Size: 4501 bytes --]

diff --git a/include/sound/ac97_codec.h b/include/sound/ac97_codec.h
--- a/include/sound/ac97_codec.h
+++ b/include/sound/ac97_codec.h
@@ -26,6 +26,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/device.h>
 #include "pcm.h"
 #include "control.h"
 #include "info.h"
@@ -520,6 +521,7 @@ struct _snd_ac97 {
 	/* jack-sharing info */
 	unsigned char indep_surround;
 	unsigned char channel_mode;
+	struct device dev;
 };
 
 /* conditions */
@@ -599,4 +601,8 @@ struct ac97_enum {
 	unsigned short mask;
 	const char **texts;
 };
+
+/* ad hoc AC97 device driver access */
+extern struct bus_type ac97_bus_type;
+
 #endif /* __SOUND_AC97_CODEC_H */
diff --git a/sound/pci/ac97/Makefile b/sound/pci/ac97/Makefile
--- a/sound/pci/ac97/Makefile
+++ b/sound/pci/ac97/Makefile
@@ -12,7 +12,7 @@ endif
 snd-ak4531-codec-objs := ak4531_codec.o
 
 # Toplevel Module Dependency
-obj-$(CONFIG_SND_AC97_CODEC) += snd-ac97-codec.o
+obj-$(CONFIG_SND_AC97_CODEC) += snd-ac97-codec.o ac97_bus.o
 obj-$(CONFIG_SND_ENS1370) += snd-ak4531-codec.o
 
 obj-m := $(sort $(obj-m))
diff --git a/sound/pci/ac97/ac97_bus.c b/sound/pci/ac97/ac97_bus.c
new file mode 100644
--- /dev/null
+++ b/sound/pci/ac97/ac97_bus.c
@@ -0,0 +1,83 @@
+/*
+ * Linux driver model AC97 bus interface
+ *
+ * Author:	Nicolas Pitre
+ * Created:	Jan 14, 2005
+ * Copyright:	(C) MontaVista Software Inc.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/string.h>
+
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/ac97_codec.h>
+
+/*
+ * Codec families have names seperated by commas, so we search for an
+ * individual codec name within the family string. 
+ */
+static int ac97_bus_match(struct device *dev, struct device_driver *drv)
+{
+	return (strstr(dev->bus_id, drv->name) != NULL);
+}
+
+static int ac97_bus_suspend(struct device *dev, pm_message_t state)
+{
+	int ret = 0;
+
+	if (dev->driver && dev->driver->suspend) {
+		ret = dev->driver->suspend(dev, state, SUSPEND_DISABLE);
+		if (ret == 0)
+			ret = dev->driver->suspend(dev, state, SUSPEND_SAVE_STATE);
+		if (ret == 0)
+			ret = dev->driver->suspend(dev, state, SUSPEND_POWER_DOWN);
+	}
+	return ret;
+}
+
+static int ac97_bus_resume(struct device *dev)
+{
+	int ret = 0;
+
+	if (dev->driver && dev->driver->resume) {
+		ret = dev->driver->resume(dev, RESUME_POWER_ON);
+		if (ret == 0)
+			ret = dev->driver->resume(dev, RESUME_RESTORE_STATE);
+		if (ret == 0)
+			ret = dev->driver->resume(dev, RESUME_ENABLE);
+	}
+	return ret;
+}
+
+struct bus_type ac97_bus_type = {
+	.name		= "ac97",
+	.match		= ac97_bus_match,
+	.suspend	= ac97_bus_suspend,
+	.resume		= ac97_bus_resume,
+};
+
+static int __init ac97_bus_init(void)
+{
+	return bus_register(&ac97_bus_type);
+}
+
+subsys_initcall(ac97_bus_init);
+
+static void __exit ac97_bus_exit(void)
+{
+	bus_unregister(&ac97_bus_type);
+}
+
+module_exit(ac97_bus_exit);
+
+EXPORT_SYMBOL(ac97_bus_type);
+
+MODULE_LICENSE("GPL");
diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
--- a/sound/pci/ac97/ac97_codec.c
+++ b/sound/pci/ac97/ac97_codec.c
@@ -992,6 +992,8 @@ static int snd_ac97_free(ac97_t *ac97)
 {
 	if (ac97) {
 		snd_ac97_proc_done(ac97);
+		if (ac97->dev.bus)
+			device_unregister(&ac97->dev);
 		if (ac97->bus) {
 			ac97->bus->codec[ac97->num] = NULL;
 			if (ac97->bus->shared_type) {
@@ -1007,6 +1009,11 @@ static int snd_ac97_free(ac97_t *ac97)
 	return 0;
 }
 
+/* Stops no dev release warning */
+static void ac97_dev_release(struct device * dev)
+{
+}
+
 static int snd_ac97_dev_free(snd_device_t *device)
 {
 	ac97_t *ac97 = device->device_data;
@@ -2117,6 +2124,14 @@ int snd_ac97_mixer(ac97_bus_t *bus, ac97
 		snd_ac97_free(ac97);
 		return err;
 	}
+
+	ac97->dev.bus = &ac97_bus_type;
+	ac97->dev.parent = ac97->bus->card->dev;
+	ac97->dev.platform_data = ac97;
+	ac97->dev.release = ac97_dev_release;
+	strncpy(ac97->dev.bus_id, snd_ac97_get_short_name(ac97), BUS_ID_SIZE);
+	if ((err = device_register(&ac97->dev)) < 0)
+		return err;
 	*rac97 = ac97;
 
 	if (bus->shared_type) {