V4L/DVB (9747): em28xx: Properly handles XCLK and I2C speed

The previous patches removed XCLK and I2C magic. Now, we finally know
what those registers do. Also, only a very few cards need different
setups for those.

Instead of keeping the setups for those values inside the per-device
hack magic switch, move the uncommon values to the board-specific
struct, and have a common setup for all other boards.

So, almost 100 lines of hacking magic were removed.

A co-lateral effect of this patch is that it also fixes a bug at em28xx-core, where xclk
were set, without taking any care about not overriding a previous xclk setup.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/em28xx/em28xx-core.c

@@ -399,7 +399,7 @@ struct em28xx_vol_table outputs[] = {
 int em28xx_audio_analog_set(struct em28xx *dev)
 {
 	int ret, i;
-	u8 xclk = 0x07;
+	u8 xclk;
 
 	if (!dev->audio_mode.has_audio)
 		return 0;
@@ -417,13 +417,11 @@ int em28xx_audio_analog_set(struct em28xx *dev)
 		}
 	}
 
-	if (dev->has_12mhz_i2s)
-		xclk |= 0x20;
-
+	xclk = dev->xclk & 0x7f;
 	if (!dev->mute)
 		xclk |= 0x80;
 
-	ret = em28xx_write_reg_bits(dev, EM28XX_R0F_XCLK, xclk, 0xa7);
+	ret = em28xx_write_reg(dev, EM28XX_R0F_XCLK, xclk);
 	if (ret < 0)
 		return ret;
 	msleep(10);

drivers/media/video/em28xx/em28xx.h

@@ -338,12 +338,13 @@ struct em28xx_board {
 	unsigned int is_em2800:1;
 	unsigned int has_msp34xx:1;
 	unsigned int mts_firmware:1;
-	unsigned int has_12mhz_i2s:1;
 	unsigned int max_range_640_480:1;
 	unsigned int has_dvb:1;
 	unsigned int has_snapshot_button:1;
 	unsigned int valid:1;
 
+	unsigned char xclk, i2c_speed;
+
 	enum em28xx_decoder decoder;
 
 	struct em28xx_input       input[MAX_EM28XX_INPUT];
@@ -422,12 +423,13 @@ struct em28xx {
 	unsigned int stream_on:1;	/* Locks streams */
 	unsigned int has_audio_class:1;
 	unsigned int has_alsa_audio:1;
-	unsigned int has_12mhz_i2s:1;
 	unsigned int max_range_640_480:1;
 	unsigned int has_dvb:1;
 	unsigned int has_snapshot_button:1;
 	unsigned int valid:1;		/* report for validated boards */
 
+	unsigned char xclk, i2c_speed;
+
 	struct em28xx_IR *ir;
 
 	/* Some older em28xx chips needs a waiting time after writing */