S5L8702: Power down I2C while it's unused

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29241 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 28 insertions, 18 deletions

diff --git a/firmware/target/arm/s5l8702/i2c-s5l8702.c b/firmware/target/arm/s5l8702/i2c-s5l8702.c
index be286b34b7..954bacbd61 100644
--- a/firmware/target/arm/s5l8702/i2c-s5l8702.c
+++ b/firmware/target/arm/s5l8702/i2c-s5l8702.c
@@ -41,33 +41,40 @@
 

 static struct mutex i2c_mtx[2];

 

-void i2c_init(void)

+static void i2c_on(int bus)

 {

-    mutex_init(&i2c_mtx[0]);

-    mutex_init(&i2c_mtx[1]);

+    /* enable I2C clock */

+    PWRCON(1) &= ~(1 << 4);

 

-    /* initial config */

-    IICADD(0) = 0;

-    IICADD(1) = 0;

-    IICCON(0) = (1 << 7) | /* ACK_GEN */

-             (0 << 6) | /* CLKSEL = PCLK/16 */

-             (1 << 5) | /* INT_EN */

-             (1 << 4) | /* IRQ clear */

-             (3 << 0);  /* CK_REG */

-    IICCON(1) = (1 << 7) | /* ACK_GEN */

-             (0 << 6) | /* CLKSEL = PCLK/16 */

-             (1 << 5) | /* INT_EN */

-             (1 << 4) | /* IRQ clear */

-             (3 << 0);  /* CK_REG */

+    IICCON(bus) = (1 << 7) | /* ACK_GEN */

+                  (0 << 6) | /* CLKSEL = PCLK/16 */

+                  (1 << 5) | /* INT_EN */

+                  (1 << 4) | /* IRQ clear */

+                  (7 << 0);  /* CK_REG */

 

     /* serial output on */

-    IICSTAT(0) = (1 << 4);

-    IICSTAT(1) = (1 << 4);

+    IICSTAT(bus) = (1 << 4);

+}

+

+static void i2c_off(int bus)

+{

+    /* serial output off */

+    IICSTAT(bus) = 0;

+

+    /* disable I2C clock */

+    PWRCON(1) |= (1 << 4);

+}

+

+void i2c_init()

+{

+    mutex_init(&i2c_mtx[0]);

+    mutex_init(&i2c_mtx[1]);

 }

 

 int i2c_write(int bus, unsigned char slave, int address, int len, const unsigned char *data)

 {

     mutex_lock(&i2c_mtx[bus]);

+        i2c_on(bus);

     long timeout = current_tick + HZ / 50;

 

     /* START */

@@ -116,6 +123,7 @@ int i2c_write(int bus, unsigned char slave, int address, int len, const unsigned
             return 5;

         }

     

+        i2c_off(bus);

     mutex_unlock(&i2c_mtx[bus]);

     return 0;

 }

@@ -123,6 +131,7 @@ int i2c_write(int bus, unsigned char slave, int address, int len, const unsigned
 int i2c_read(int bus, unsigned char slave, int address, int len, unsigned char *data)

 {

     mutex_lock(&i2c_mtx[bus]);

+        i2c_on(bus);

     long timeout = current_tick + HZ / 50;

 

     if (address >= 0) {

@@ -180,6 +189,7 @@ int i2c_read(int bus, unsigned char slave, int address, int len, unsigned char *
             return 5;

         }

     

+        i2c_off(bus);

     mutex_unlock(&i2c_mtx[bus]);

     return 0;

 }