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drivers: i2c: mxc: Add early init 

Add early i2c init function with conservative divider when the exact
clock rate is not available.

Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
This commit is contained in:
Yuan Yao 2016-06-08 18:24:51 +08:00 committed by York Sun
parent 30677deefd
commit 9d10c2d3fe
3 changed files with 35 additions and 0 deletions
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5
drivers/i2c/i2c_core.c
View File

@ -233,6 +233,11 @@ __weak void i2c_init_board(void)
{
}
/* implement possible for i2c specific early i2c init */
__weak void i2c_early_init_f(void)
{
}
/*
* i2c_init_all():
*

27
drivers/i2c/mxc_i2c.c
View File

@ -32,6 +32,14 @@ DECLARE_GLOBAL_DATA_PTR;
#define IMX_I2C_REGSHIFT 2
#define VF610_I2C_REGSHIFT 0
#define I2C_EARLY_INIT_INDEX 0
#ifdef CONFIG_SYS_I2C_IFDR_DIV
#define I2C_IFDR_DIV_CONSERVATIVE CONFIG_SYS_I2C_IFDR_DIV
#else
#define I2C_IFDR_DIV_CONSERVATIVE 0x7e
#endif
/* Register index */
#define IADR 0
#define IFDR 1
@ -659,6 +667,25 @@ void bus_i2c_init(int index, int speed, int unused,
bus_i2c_set_bus_speed(&mxc_i2c_buses[index], speed);
}
/*
* Early init I2C for prepare read the clk through I2C.
*/
void i2c_early_init_f(void)
{
ulong base = mxc_i2c_buses[I2C_EARLY_INIT_INDEX].base;
bool quirk = mxc_i2c_buses[I2C_EARLY_INIT_INDEX].driver_data
& I2C_QUIRK_FLAG ? true : false;
int reg_shift = quirk ? VF610_I2C_REGSHIFT : IMX_I2C_REGSHIFT;
/* Set I2C divider value */
writeb(I2C_IFDR_DIV_CONSERVATIVE, base + (IFDR << reg_shift));
/* Reset module */
writeb(I2CR_IDIS, base + (I2CR << reg_shift));
writeb(0, base + (I2SR << reg_shift));
/* Enable I2C */
writeb(I2CR_IEN, base + (I2CR << reg_shift));
}
/*
* Init I2C Bus
*/

3
include/i2c.h
View File

@ -701,6 +701,9 @@ extern struct i2c_bus_hose i2c_bus[];
* Initialization, must be called once on start up, may be called
* repeatedly to change the speed and slave addresses.
*/
#ifdef CONFIG_SYS_I2C_EARLY_INIT
void i2c_early_init_f(void);
#endif
void i2c_init(int speed, int slaveaddr);
void i2c_init_board(void);
#ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT