[PATCH 1/5] i2c: stm32f7: fix configuration of the digital filter

[Pierre Yves MORDRET]

Hello all

Looks good to me

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret at foss.st.com>

Regards

On 2/5/21 9:51 AM, Alain Volmat wrote:
> The digital filter related computation are present in the driver
> however the programming of the filter within the IP is missing.
> The maximum value for the DNF is wrong and should be 15 instead of 16.
> 
> Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver")
> 
> Signed-off-by: Alain Volmat <alain.volmat at foss.st.com>
> ---
>  drivers/i2c/busses/i2c-stm32f7.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index 9aa8e65b511e..473fbe144b7e 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -57,6 +57,8 @@
>  #define STM32F7_I2C_CR1_RXDMAEN			BIT(15)
>  #define STM32F7_I2C_CR1_TXDMAEN			BIT(14)
>  #define STM32F7_I2C_CR1_ANFOFF			BIT(12)
> +#define STM32F7_I2C_CR1_DNF_MASK		GENMASK(11, 8)
> +#define STM32F7_I2C_CR1_DNF(n)			(((n) & 0xf) << 8)
>  #define STM32F7_I2C_CR1_ERRIE			BIT(7)
>  #define STM32F7_I2C_CR1_TCIE			BIT(6)
>  #define STM32F7_I2C_CR1_STOPIE			BIT(5)
> @@ -160,7 +162,7 @@ enum {
>  };
>  
>  #define STM32F7_I2C_DNF_DEFAULT			0
> -#define STM32F7_I2C_DNF_MAX			16
> +#define STM32F7_I2C_DNF_MAX			15
>  
>  #define STM32F7_I2C_ANALOG_FILTER_ENABLE	1
>  #define STM32F7_I2C_ANALOG_FILTER_DELAY_MIN	50	/* ns */
> @@ -725,6 +727,13 @@ static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev)
>  	else
>  		stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
>  				     STM32F7_I2C_CR1_ANFOFF);
> +
> +	/* Program the Digital Filter */
> +	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
> +			     STM32F7_I2C_CR1_DNF_MASK);
> +	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
> +			     STM32F7_I2C_CR1_DNF(i2c_dev->setup.dnf));
> +
>  	stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
>  			     STM32F7_I2C_CR1_PE);
>  }
> 

-- 
--
~ Py MORDRET
--