T114 has a slightly different I2C clock, with a new divisor for standard/fast mode and HS mode. Tested on my Dalmore, and the I2C clock is 100KHz +/- 3% on my Saleae Logic analyzer.
Signed-off-by: Tom Warren twarren@nvidia.com --- v2: new
arch/arm/include/asm/arch-tegra/tegra_i2c.h | 6 ++++++ drivers/i2c/tegra_i2c.c | 22 +++++++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletions(-)
diff --git a/arch/arm/include/asm/arch-tegra/tegra_i2c.h b/arch/arm/include/asm/arch-tegra/tegra_i2c.h index 2650744..853e59b 100644 --- a/arch/arm/include/asm/arch-tegra/tegra_i2c.h +++ b/arch/arm/include/asm/arch-tegra/tegra_i2c.h @@ -105,6 +105,7 @@ struct i2c_ctlr { u32 sl_delay_count; /* 3C: I2C_I2C_SL_DELAY_COUNT */ u32 reserved_2[4]; /* 40: */ struct i2c_control control; /* 50 ~ 68 */ + u32 clk_div; /* 6C: I2C_I2C_CLOCK_DIVISOR */ };
/* bit fields definitions for IO Packet Header 1 format */ @@ -154,6 +155,11 @@ struct i2c_ctlr { #define I2C_INT_ARBITRATION_LOST_SHIFT 2 #define I2C_INT_ARBITRATION_LOST_MASK (1 << I2C_INT_ARBITRATION_LOST_SHIFT)
+/* I2C_CLK_DIVISOR_REGISTER */ +#define CLK_DIV_STD_FAST_MODE 0x19 +#define CLK_DIV_HS_MODE 1 +#define CLK_MULT_STD_FAST_MODE 8 + /** * Returns the bus number of the DVC controller * diff --git a/drivers/i2c/tegra_i2c.c b/drivers/i2c/tegra_i2c.c index efc77fa..0558648 100644 --- a/drivers/i2c/tegra_i2c.c +++ b/drivers/i2c/tegra_i2c.c @@ -88,7 +88,27 @@ static void i2c_init_controller(struct i2c_bus *i2c_bus) * 16 to get the right frequency. */ clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH, - i2c_bus->speed * 2 * 8); + i2c_bus->speed * 2 * 8); +#if defined(CONFIG_TEGRA114) + /* + * T114 I2C went to a single clock source for standard/fast and + * HS clock speeds. The new clock rate setting calculation is: + * SCL = CLK_SOURCE.I2C / + * (CLK_MULT_STD_FAST_MODE * (I2C_CLK_DIV_STD_FAST_MODE+1) * + * I2C FREQUENCY DIVISOR) as per the T114 TRM (sec 30.3.1). + * + * NOTE: We do this here, after the initial clock/pll start, + * because if we read the clk_div reg before the controller + * is running, we hang, and we need it for the new calc. + */ + int clk_div_std_fast_mode = readl(&i2c_bus->regs->clk_div) >> 16; + debug("%s: CLK_DIV_STD_FAST_MODE setting = %d\n", __func__, + clk_div_std_fast_mode); + + clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH, + CLK_MULT_STD_FAST_MODE * (clk_div_std_fast_mode+1) * + i2c_bus->speed * 2); +#endif /* T114 */
/* Reset I2C controller. */ i2c_reset_controller(i2c_bus);