[ALSA] oxygen: add I2C support

Add a function to write I2C registers.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 22 insertions, 2 deletions

diff --git a/sound/pci/oxygen/oxygen.h b/sound/pci/oxygen/oxygen.h
index 2f25c8dbaf85..d53c18c6fcd8 100644
--- a/sound/pci/oxygen/oxygen.h
+++ b/sound/pci/oxygen/oxygen.h
@@ -146,6 +146,7 @@ void oxygen_write_ac97_masked(struct oxygen *chip, unsigned int codec,
                               unsigned int index, u16 data, u16 mask);
 
 void oxygen_write_spi(struct oxygen *chip, u8 control, unsigned int data);
+void oxygen_write_i2c(struct oxygen *chip, u8 device, u8 map, u8 data);
 
 static inline void oxygen_set_bits8(struct oxygen *chip,
                                     unsigned int reg, u8 value)
diff --git a/sound/pci/oxygen/oxygen_io.c b/sound/pci/oxygen/oxygen_io.c
index 74e23ef9c946..5569606ee87f 100644
--- a/sound/pci/oxygen/oxygen_io.c
+++ b/sound/pci/oxygen/oxygen_io.c
@@ -190,12 +190,31 @@ void oxygen_write_spi(struct oxygen *chip, u8 control, unsigned int data)
                 --count;
         }
 
-        spin_lock_irq(&chip->reg_lock);
         oxygen_write8(chip, OXYGEN_SPI_DATA1, data);
         oxygen_write8(chip, OXYGEN_SPI_DATA2, data >> 8);
         if (control & OXYGEN_SPI_DATA_LENGTH_3)
                 oxygen_write8(chip, OXYGEN_SPI_DATA3, data >> 16);
         oxygen_write8(chip, OXYGEN_SPI_CONTROL, control);
-        spin_unlock_irq(&chip->reg_lock);
 }
 EXPORT_SYMBOL(oxygen_write_spi);
+
+void oxygen_write_i2c(struct oxygen *chip, u8 device, u8 map, u8 data)
+{
+        unsigned long timeout;
+
+        /* should not need more than about 300 us */
+        timeout = jiffies + msecs_to_jiffies(1);
+        do {
+                if (!(oxygen_read16(chip, OXYGEN_2WIRE_BUS_STATUS)
+                      & OXYGEN_2WIRE_BUSY))
+                        break;
+                udelay(1);
+                cond_resched();
+        } while (time_after_eq(timeout, jiffies));
+
+        oxygen_write8(chip, OXYGEN_2WIRE_MAP, map);
+        oxygen_write8(chip, OXYGEN_2WIRE_DATA, data);
+        oxygen_write8(chip, OXYGEN_2WIRE_CONTROL,
+                      device | OXYGEN_2WIRE_DIR_WRITE);
+}
+EXPORT_SYMBOL(oxygen_write_i2c);