[ALSA] oxygen: revert SPI clock frequency change for AK4396/WM8785

While the AK4396 and WM8785 datasheets say that the SPI clock cycle
length must be at least 200 ns, 320 ns seems not to work reliably with
the controller, so we better use 160 ns.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/oxygen/hifier.c

@@ -56,7 +56,7 @@ static void ak4396_write(struct oxygen *chip, u8 reg, u8 value)
 {
 	oxygen_write_spi(chip, OXYGEN_SPI_TRIGGER  |
 			 OXYGEN_SPI_DATA_LENGTH_2 |
-			 OXYGEN_SPI_CLOCK_320 |
+			 OXYGEN_SPI_CLOCK_160 |
 			 (0 << OXYGEN_SPI_CODEC_SHIFT) |
 			 OXYGEN_SPI_CEN_LATCH_CLOCK_HI,
 			 AK4396_WRITE | (reg << 8) | value);

sound/pci/oxygen/oxygen.c

@@ -129,7 +129,7 @@ static void ak4396_write(struct oxygen *chip, unsigned int codec,
 	};
 	oxygen_write_spi(chip, OXYGEN_SPI_TRIGGER |
 			 OXYGEN_SPI_DATA_LENGTH_2 |
-			 OXYGEN_SPI_CLOCK_320 |
+			 OXYGEN_SPI_CLOCK_160 |
 			 (codec_spi_map[codec] << OXYGEN_SPI_CODEC_SHIFT) |
 			 OXYGEN_SPI_CEN_LATCH_CLOCK_HI,
 			 AK4396_WRITE | (reg << 8) | value);
@@ -139,7 +139,7 @@ static void wm8785_write(struct oxygen *chip, u8 reg, unsigned int value)
 {
 	oxygen_write_spi(chip, OXYGEN_SPI_TRIGGER |
 			 OXYGEN_SPI_DATA_LENGTH_2 |
-			 OXYGEN_SPI_CLOCK_320 |
+			 OXYGEN_SPI_CLOCK_160 |
 			 (3 << OXYGEN_SPI_CODEC_SHIFT) |
 			 OXYGEN_SPI_CEN_LATCH_CLOCK_LO,
 			 (reg << 9) | value);