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authorGuennadi Liakhovetski <lg@denx.de>2009-02-13 09:23:36 +0100
committerHeiko Schocher <hs@denx.de>2009-02-14 10:00:51 +0100
commite7de18afe8ecf96a51ef981d06066eeb6b1254e7 (patch)
tree7bea693fa69e5ed7cab9d1fe7ae96c6c31ece3eb
parent15208ac9eae1c340c4bc11f70cbf5c9da78a57ba (diff)
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i.MX31: Start the I2C clock on driver initialisation
i.MX31 powers on with most clocks running, so, after a power on this explicit clock start up is not required. However, as Linux boots it disables most clocks to save power. This includes the I2C clock. If we then soft reboot from Linux the I2C clock stays off. This breaks the phycore, which has its environment in I2C EEPROM. Fix the problem by explicitly starting the clock in I2C driver initialisation routine. Signed-off-by: Guennadi Liakhovetski <lg@denx.de> Ack-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
-rw-r--r--drivers/i2c/mxc_i2c.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
index eedad06..8e10fbb 100644
--- a/drivers/i2c/mxc_i2c.c
+++ b/drivers/i2c/mxc_i2c.c
@@ -49,10 +49,13 @@
#ifdef CONFIG_SYS_I2C_MX31_PORT1
#define I2C_BASE 0x43f80000
+#define I2C_CLK_OFFSET 26
#elif defined (CONFIG_SYS_I2C_MX31_PORT2)
#define I2C_BASE 0x43f98000
+#define I2C_CLK_OFFSET 28
#elif defined (CONFIG_SYS_I2C_MX31_PORT3)
#define I2C_BASE 0x43f84000
+#define I2C_CLK_OFFSET 30
#else
#error "define CONFIG_SYS_I2C_MX31_PORTx to use the mx31 I2C driver"
#endif
@@ -72,6 +75,9 @@ void i2c_init(int speed, int unused)
int freq = mx31_get_ipg_clk();
int i;
+ /* start the required I2C clock */
+ __REG(CCM_CGR0) = __REG(CCM_CGR0) | (3 << I2C_CLK_OFFSET);
+
for (i = 0; i < 0x1f; i++)
if (freq / div[i] <= speed)
break;