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i2c: mxs: Implement i2c_get/set_bus_speed()

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This patch implements the setup and retrieval functions for the I2C
bus speed on the MXS I2C IP.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
This commit is contained in:
Marek Vasut 2012-11-12 14:34:29 +00:00 • committed by Tom Rini
parent f32a470ed3
commit a06f590f7f
1 changed files with 45 additions and 0 deletions
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45
drivers/i2c/mxs_i2c.c
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@ -240,6 +240,51 @@ static struct mxs_i2c_speed_table *mxs_i2c_speed_to_cfg(uint32_t speed)
return NULL;
}
static uint32_t mxs_i2c_cfg_to_speed(uint32_t timing0, uint32_t timing1)
{
int i;
for (i = 0; i < ARRAY_SIZE(mxs_i2c_tbl); i++) {
if (mxs_i2c_tbl[i].timing0 != timing0)
continue;
if (mxs_i2c_tbl[i].timing1 != timing1)
continue;
return mxs_i2c_tbl[i].speed;
}
return 0;
}
int i2c_set_bus_speed(unsigned int speed)
{
struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
struct mxs_i2c_speed_table *spd = mxs_i2c_speed_to_cfg(speed);
if (!spd) {
printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed);
return -EINVAL;
}
writel(spd->timing0, &i2c_regs->hw_i2c_timing0);
writel(spd->timing1, &i2c_regs->hw_i2c_timing1);
writel((0x0015 << I2C_TIMING2_BUS_FREE_OFFSET) |
(0x000d << I2C_TIMING2_LEADIN_COUNT_OFFSET),
&i2c_regs->hw_i2c_timing2);
return 0;
}
unsigned int i2c_get_bus_speed(void)
{
struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
uint32_t timing0, timing1;
timing0 = readl(&i2c_regs->hw_i2c_timing0);
timing1 = readl(&i2c_regs->hw_i2c_timing1);
return mxs_i2c_cfg_to_speed(timing0, timing1);
}
void i2c_init(int speed, int slaveadd)
{
struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;