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authorMarek Vasut <marek.vasut@gmail.com>2011-10-26 00:05:44 +0000
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2011-11-03 22:56:19 +0100
commitbf0783df0d64772706db4bda0eec7197ea3bf21b (patch)
tree342c7baa6f16efd7f2219b9824d3810b1d4d4a6a
parentd28d6a96192d69acd99ebe7031908f18f8765262 (diff)
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I2C: Fix mxc_i2c.c problem on imx31_phycore
The problem was caused by a global variable being used early in the boot process. The symptoms were on imx31_phycore board, reading the environment from I2C EEPROM didn't work correctly and causes default environment to be loaded. Signed-off-by: Marek Vasut <marek.vasut@gmail.com> Cc: Wolfgang Denk <wd@denx.de> Cc: Albert ARIBAUD <albert.u.boot@aribaud.net> Cc: Heiko Schocher <hs@denx.de> Cc: Stefano Babic <sbabic@denx.de> Acked-by: Heiko Schocher <hs@denx.de> Tested-by: Anatolij Gustschin <agust@denx.de> Tested-by: Stefano Babic <sbabic@denx.de>
-rw-r--r--drivers/i2c/mxc_i2c.c37
1 files changed, 26 insertions, 11 deletions
diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
index bf3ad95..c88ac7c 100644
--- a/drivers/i2c/mxc_i2c.c
+++ b/drivers/i2c/mxc_i2c.c
@@ -37,6 +37,7 @@
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
+#include <i2c.h>
struct mxc_i2c_regs {
uint32_t iadr;
@@ -99,16 +100,14 @@ static u16 i2c_clk_div[50][2] = {
{ 3072, 0x1E }, { 3840, 0x1F }
};
-static u8 clk_div;
-
/*
* Calculate and set proper clock divider
*/
-static void i2c_imx_set_clk(unsigned int rate)
+static uint8_t i2c_imx_get_clk(unsigned int rate)
{
- struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
unsigned int i2c_clk_rate;
unsigned int div;
+ u8 clk_div;
#if defined(CONFIG_MX31)
struct clock_control_regs *sc_regs =
@@ -131,7 +130,7 @@ static void i2c_imx_set_clk(unsigned int rate)
;
/* Store divider value */
- writeb(i2c_clk_div[clk_div][1], &i2c_regs->ifdr);
+ return clk_div;
}
/*
@@ -150,7 +149,13 @@ void i2c_reset(void)
*/
void i2c_init(int speed, int unused)
{
- i2c_imx_set_clk(speed);
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
+ u8 clk_idx = i2c_imx_get_clk(speed);
+ u8 idx = i2c_clk_div[clk_idx][1];
+
+ /* Store divider value */
+ writeb(idx, &i2c_regs->ifdr);
+
i2c_reset();
}
@@ -168,6 +173,13 @@ int i2c_set_bus_speed(unsigned int speed)
*/
unsigned int i2c_get_bus_speed(void)
{
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
+ u8 clk_idx = readb(&i2c_regs->ifdr);
+ u8 clk_div;
+
+ for (clk_div = 0; i2c_clk_div[clk_div][1] != clk_idx; clk_div++)
+ ;
+
return mxc_get_clock(MXC_IPG_PERCLK) / i2c_clk_div[clk_div][0];
}
@@ -236,8 +248,12 @@ int i2c_imx_start(void)
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
unsigned int temp = 0;
int result;
+ int speed = i2c_get_bus_speed();
+ u8 clk_idx = i2c_imx_get_clk(speed);
+ u8 idx = i2c_clk_div[clk_idx][1];
- writeb(i2c_clk_div[clk_div][1], &i2c_regs->ifdr);
+ /* Store divider value */
+ writeb(idx, &i2c_regs->ifdr);
/* Enable I2C controller */
writeb(0, &i2c_regs->i2sr);
@@ -310,11 +326,10 @@ int i2c_imx_set_chip_addr(uchar chip, int read)
int i2c_imx_set_reg_addr(uint addr, int alen)
{
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
- int ret;
- int i;
+ int ret = 0;
- for (i = 0; i < (8 * alen); i += 8) {
- writeb((addr >> i) & 0xff, &i2c_regs->i2dr);
+ while (alen--) {
+ writeb((addr >> (alen * 8)) & 0xff, &i2c_regs->i2dr);
ret = i2c_imx_trx_complete();
if (ret)