[PATCH v1 6/7] i2c: stm32f7: add support for DNF i2c-digital-filter binding

[Patrice CHOTARD]

HI Patrick

On 8/3/21 12:05 PM, Patrice Chotard wrote:
> From: Patrick Delaunay <patrick.delaunay at foss.st.com>
> 
> Add the support for the i2c-digital-filter binding, allowing to enable
> the digital filter via the device-tree and indicate its value in the DT
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
> ---
> 
>  drivers/i2c/stm32f7_i2c.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/i2c/stm32f7_i2c.c b/drivers/i2c/stm32f7_i2c.c
> index 7e6c65fadc..2b2dae67a3 100644
> --- a/drivers/i2c/stm32f7_i2c.c
> +++ b/drivers/i2c/stm32f7_i2c.c
> @@ -107,7 +107,6 @@ struct stm32_i2c_regs {
>  
>  #define STM32_I2C_MAX_LEN			0xff
>  
> -#define STM32_I2C_DNF_DEFAULT			0
>  #define STM32_I2C_DNF_MAX			15
>  
>  #define STM32_I2C_ANALOG_FILTER_DELAY_MIN	50	/* ns */
> @@ -204,6 +203,7 @@ struct stm32_i2c_timings {
>   * @regmap_sreg: register address for setting Fast Mode Plus bits
>   * @regmap_creg: register address for clearing Fast Mode Plus bits
>   * @regmap_mask: mask for Fast Mode Plus bits
> + * @dnf_dt: value of digital filter requested via dt
>   */
>  struct stm32_i2c_priv {
>  	struct stm32_i2c_regs *regs;
> @@ -214,6 +214,7 @@ struct stm32_i2c_priv {
>  	u32 regmap_sreg;
>  	u32 regmap_creg;
>  	u32 regmap_mask;
> +	u32 dnf_dt;
>  };
>  
>  static const struct stm32_i2c_spec i2c_specs[] = {
> @@ -684,6 +685,7 @@ static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv,
>  	const struct stm32_i2c_spec *specs;
>  	struct stm32_i2c_timings *v, *_v;
>  	struct list_head solutions;
> +	u32 i2cclk = DIV_ROUND_CLOSEST(STM32_NSEC_PER_SEC, setup->clock_src);
>  	int ret;
>  
>  	specs = get_specs(setup->speed_freq);
> @@ -701,6 +703,8 @@ static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv,
>  		return -EINVAL;
>  	}
>  
> +	/*  Analog and Digital Filters */
> +	setup->dnf = DIV_ROUND_CLOSEST(i2c_priv->dnf_dt, i2cclk);
>  	if (setup->dnf > STM32_I2C_DNF_MAX) {
>  		log_err("DNF out of bound %d/%d\n",
>  			setup->dnf, STM32_I2C_DNF_MAX);
> @@ -923,7 +927,10 @@ static int stm32_of_to_plat(struct udevice *dev)
>  	fall_time = dev_read_u32_default(dev, "i2c-scl-falling-time-ns",
>  					 STM32_I2C_FALL_TIME_DEFAULT);
>  
> -	i2c_priv->setup.dnf = STM32_I2C_DNF_DEFAULT;
> +	i2c_priv->dnf_dt = dev_read_u32_default(dev, "i2c-digital-filter-width-ns", 0);
> +	if (!dev_read_bool(dev, "i2c-digital-filter"))
> +		i2c_priv->dnf_dt = 0;
> +
>  	i2c_priv->setup.analog_filter = dev_read_bool(dev, "i2c-analog-filter");
>  
>  	/* Optional */
> 
Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>

Thanks
Patrice