Mirrors/u-boot
2
0
Fork 0
mirror of https://github.com/AsahiLinux/u-boot synced 2024-11-24 21:54:01 +00:00
Code Issues Projects Releases Packages Wiki Activity

i.MX31: Start the I2C clock on driver initialisation

Browse source 
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>
This commit is contained in:
Guennadi Liakhovetski 2009-02-13 09:23:36 +01:00 committed by Heiko Schocher
parent 15208ac9ea
commit e7de18afe8
1 changed files with 6 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/i2c/mxc_i2c.c
View file

@ -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;