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 --- drivers/i2c/mxs_i2c.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)
diff --git a/drivers/i2c/mxs_i2c.c b/drivers/i2c/mxs_i2c.c index 98f6e8c..4152242 100644 --- a/drivers/i2c/mxs_i2c.c +++ b/drivers/i2c/mxs_i2c.c @@ -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;