linux-kernel - Re: [PATCH 2/2] iio: ad74413r: wire up support for drive-strength-microamp property

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Message-ID: <20230303151438.00003842@Huawei.com>
Date:   Fri, 3 Mar 2023 15:14:38 +0000
From:   Jonathan Cameron <Jonathan.Cameron@...wei.com>
To:     Rasmus Villemoes <linux@...musvillemoes.dk>
CC:     Lars-Peter Clausen <lars@...afoo.de>,
        Michael Hennerich <Michael.Hennerich@...log.com>,
        Cosmin Tanislav <cosmin.tanislav@...log.com>,
        Jonathan Cameron <jic23@...nel.org>,
        <devicetree@...r.kernel.org>, Rob Herring <robh+dt@...nel.org>,
        <linux-iio@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] iio: ad74413r: wire up support for
 drive-strength-microamp property

On Thu,  2 Mar 2023 14:49:21 +0100
Rasmus Villemoes <linux@...musvillemoes.dk> wrote:

> Use the value specified in the channel configuration node to populate
> the DIN_SINK field of the DIN_CONFIGx register.
> 
> Signed-off-by: Rasmus Villemoes <linux@...musvillemoes.dk>
Hi Rasmus,

 Given you are doing a v2 for the binding issue
Rob's bot noted. One trivial comment inline.
(I'd have ignored it if everything else was fine!)

Thanks,

Jonathan

> ---
>  drivers/iio/addac/ad74413r.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
> index f32c8c2fb26d..cbf0f66fdc74 100644
> --- a/drivers/iio/addac/ad74413r.c
> +++ b/drivers/iio/addac/ad74413r.c
> @@ -39,6 +39,7 @@ struct ad74413r_chip_info {
>  
>  struct ad74413r_channel_config {
>  	u32		func;
> +	u32		drive_strength;
>  	bool		gpo_comparator;
>  	bool		initialized;
>  };
> @@ -111,6 +112,7 @@ struct ad74413r_state {
>  #define AD74413R_REG_DIN_CONFIG_X(x)	(0x09 + (x))
>  #define AD74413R_DIN_DEBOUNCE_MASK	GENMASK(4, 0)
>  #define AD74413R_DIN_DEBOUNCE_LEN	BIT(5)
> +#define AD74413R_DIN_SINK_MASK		GENMASK(9, 6)
>  
>  #define AD74413R_REG_DAC_CODE_X(x)	(0x16 + (x))
>  #define AD74413R_DAC_CODE_MAX		GENMASK(12, 0)
> @@ -261,6 +263,19 @@ static int ad74413r_set_comp_debounce(struct ad74413r_state *st,
>  				  val);
>  }
>  
> +static int ad74413r_set_comp_drive_strength(struct ad74413r_state *st,
> +					    unsigned int offset,
> +					    unsigned int strength)
> +{
> +	if (strength > 1800)
> +		strength = 1800;

trivial but I think
	strength = min(strength, 1800);
is perhaps a little more readable?

> +
> +	return regmap_update_bits(st->regmap, AD74413R_REG_DIN_CONFIG_X(offset),
> +				  AD74413R_DIN_SINK_MASK,
> +				  FIELD_PREP(AD74413R_DIN_SINK_MASK, strength / 120));
> +}
> +
> +
>  static void ad74413r_gpio_set(struct gpio_chip *chip,
>  			      unsigned int offset, int val)
>  {
> @@ -1190,6 +1205,9 @@ static int ad74413r_parse_channel_config(struct iio_dev *indio_dev,
>  	config->gpo_comparator = fwnode_property_read_bool(channel_node,
>  		"adi,gpo-comparator");
>  
> +	fwnode_property_read_u32(channel_node, "drive-strength-microamp",
> +				 &config->drive_strength);
> +
>  	if (!config->gpo_comparator)
>  		st->num_gpo_gpios++;
>  
> @@ -1269,6 +1287,7 @@ static int ad74413r_setup_gpios(struct ad74413r_state *st)
>  	unsigned int gpo_gpio_i = 0;
>  	unsigned int i;
>  	u8 gpo_config;
> +	u32 strength;
>  	int ret;
>  
>  	for (i = 0; i < AD74413R_CHANNEL_MAX; i++) {
> @@ -1285,6 +1304,11 @@ static int ad74413r_setup_gpios(struct ad74413r_state *st)
>  		    config->func == CH_FUNC_DIGITAL_INPUT_LOOP_POWER)
>  			st->comp_gpio_offsets[comp_gpio_i++] = i;
>  
> +		strength = config->drive_strength;
> +		ret = ad74413r_set_comp_drive_strength(st, i, strength);
> +		if (ret)
> +			return ret;
> +
>  		ret = ad74413r_set_gpo_config(st, i, gpo_config);
>  		if (ret)
>  			return ret;