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mxc_i2c: prep work for multiple busses support 

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
This commit is contained in:
Troy Kisky 2012-07-19 08:18:18 +00:00 committed by Heiko Schocher
parent 27a5da02c0
commit e4ff525f91
1 changed files with 104 additions and 21 deletions
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125
drivers/i2c/mxc_i2c.c
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@ -59,9 +59,7 @@ struct mxc_i2c_regs {
#define I2SR_IIF (1 << 1)
#define I2SR_RX_NO_AK (1 << 0)
#ifdef CONFIG_SYS_I2C_BASE
#define I2C_BASE CONFIG_SYS_I2C_BASE
#else
#if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE)
#error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver"
#endif
@ -115,11 +113,11 @@ static uint8_t i2c_imx_get_clk(unsigned int rate)
}
/*
* Init I2C Bus
* Set I2C Bus speed
*/
void i2c_init(int speed, int unused)
int bus_i2c_set_bus_speed(void *base, int speed)
{
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
u8 clk_idx = i2c_imx_get_clk(speed);
u8 idx = i2c_clk_div[clk_idx][1];
@ -129,23 +127,15 @@ void i2c_init(int speed, int unused)
/* Reset module */
writeb(0, &i2c_regs->i2cr);
writeb(0, &i2c_regs->i2sr);
}
/*
* Set I2C Speed
*/
int i2c_set_bus_speed(unsigned int speed)
{
i2c_init(speed, 0);
return 0;
}
/*
* Get I2C Speed
*/
unsigned int i2c_get_bus_speed(void)
unsigned int bus_i2c_get_bus_speed(void *base)
{
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
u8 clk_idx = readb(&i2c_regs->ifdr);
u8 clk_div;
@ -287,12 +277,13 @@ static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs,
/*
* Read data from I2C device
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf,
int len)
{
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
int ret;
unsigned int temp;
int i;
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
if (ret < 0)
@ -346,11 +337,12 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
/*
* Write data to I2C device
*/
int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
int bus_i2c_write(void *base, uchar chip, uint addr, int alen,
const uchar *buf, int len)
{
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
int ret;
int i;
struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
if (ret < 0)
@ -365,10 +357,101 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
return ret;
}
struct i2c_parms {
void *base;
void *idle_bus_data;
int (*idle_bus_fn)(void *p);
};
struct sram_data {
unsigned curr_i2c_bus;
struct i2c_parms i2c_data[3];
};
/*
* For SPL boot some boards need i2c before SDRAM is initialized so force
* variables to live in SRAM
*/
static struct sram_data __attribute__((section(".data"))) srdata;
void *get_base(void)
{
#ifdef CONFIG_SYS_I2C_BASE
#ifdef CONFIG_I2C_MULTI_BUS
void *ret = srdata.i2c_data[srdata.curr_i2c_bus].base;
if (ret)
return ret;
#endif
return (void *)CONFIG_SYS_I2C_BASE;
#elif defined(CONFIG_I2C_MULTI_BUS)
return srdata.i2c_data[srdata.curr_i2c_bus].base;
#else
return srdata.i2c_data[0].base;
#endif
}
int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
{
return bus_i2c_read(get_base(), chip, addr, alen, buf, len);
}
int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
{
return bus_i2c_write(get_base(), chip, addr, alen, buf, len);
}
/*
* Test if a chip at a given address responds (probe the chip)
*/
int i2c_probe(uchar chip)
{
return i2c_write(chip, 0, 0, NULL, 0);
return bus_i2c_write(get_base(), chip, 0, 0, NULL, 0);
}
void bus_i2c_init(void *base, int speed, int unused,
int (*idle_bus_fn)(void *p), void *idle_bus_data)
{
int i = 0;
struct i2c_parms *p = srdata.i2c_data;
if (!base)
return;
for (;;) {
if (!p->base || (p->base == base)) {
p->base = base;
if (idle_bus_fn) {
p->idle_bus_fn = idle_bus_fn;
p->idle_bus_data = idle_bus_data;
}
break;
}
p++;
i++;
if (i >= ARRAY_SIZE(srdata.i2c_data))
return;
}
bus_i2c_set_bus_speed(base, speed);
}
/*
* Init I2C Bus
*/
void i2c_init(int speed, int unused)
{
bus_i2c_init(get_base(), speed, unused, NULL, NULL);
}
/*
* Set I2C Speed
*/
int i2c_set_bus_speed(unsigned int speed)
{
return bus_i2c_set_bus_speed(get_base(), speed);
}
/*
* Get I2C Speed
*/
unsigned int i2c_get_bus_speed(void)
{
return bus_i2c_get_bus_speed(get_base());
}