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S5L8702: Power down I2C while it's unused

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29241 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Michael Sparmann 2011-02-07 18:43:05 +00:00
parent 37e2c9c313
commit 87da25c87c
1 changed files with 29 additions and 19 deletions
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48
firmware/target/arm/s5l8702/i2c-s5l8702.c
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@ -41,33 +41,40 @@
static struct mutex i2c_mtx[2];
void i2c_init(void)
static void i2c_on(int bus)
{
/* enable I2C clock */
PWRCON(1) &= ~(1 << 4);
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(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]);
/* 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 */
/* serial output on */
IICSTAT(0) = (1 << 4);
IICSTAT(1) = (1 << 4);
}
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;
}