ALSA: tea575x: unify read/write functions

Implement generic read/write functions to access TEA575x tuners. They're now
implemented 4 times (once in es1968 and 3 times in fm801).
This also allows mute to work on all cards.
Also improve tuner detection/initialization.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/tea575x-tuner.h b/include/sound/tea575x-tuner.h
index 5aade56..e50cb29 100644
--- a/include/sound/tea575x-tuner.h
+++ b/include/sound/tea575x-tuner.h
@@ -26,12 +26,17 @@
 #include <media/v4l2-dev.h>
 #include <media/v4l2-ioctl.h>
 
+#define TEA575X_DATA	(1 << 0)
+#define TEA575X_CLK	(1 << 1)
+#define TEA575X_WREN	(1 << 2)
+#define TEA575X_MOST	(1 << 3)
+
 struct snd_tea575x;
 
 struct snd_tea575x_ops {
-	void (*write)(struct snd_tea575x *tea, unsigned int val);
-	unsigned int (*read)(struct snd_tea575x *tea);
-	void (*mute)(struct snd_tea575x *tea, unsigned int mute);
+	void (*set_pins)(struct snd_tea575x *tea, u8 pins);
+	u8 (*get_pins)(struct snd_tea575x *tea);
+	void (*set_direction)(struct snd_tea575x *tea, bool output);
 };
 
 struct snd_tea575x {
@@ -49,7 +54,7 @@
 	void *private_data;
 };
 
-void snd_tea575x_init(struct snd_tea575x *tea);
+int snd_tea575x_init(struct snd_tea575x *tea);
 void snd_tea575x_exit(struct snd_tea575x *tea);
 
 #endif /* __SOUND_TEA575X_TUNER_H */