Re: [PATCH 26/40] mfd: ti_am335x_tscadc: Introduce has_tsc

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 25 Aug 2021 17:25:04 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> One way of knowing which hardware we are dealing with is to check its
> compatible. When this must be done at several places, it's best to use a
> proper boolean for that. ->has_tsc indicates if there is a touchscreen
> controller available (meaning it's a am33xx-like ADC) or not but does
> not indicate if it is actually used (that is the purpose of the use_tsc
> boolean in the probe).
> 
> Introducing this boolean helps making a difference in the code between
> what is generic to both types of ADCs and what is specific to the am33xx
> hardware before introducing support for the am437x hardware.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Seems sensible to me.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/mfd/ti_am335x_tscadc.c       | 37 +++++++++++++++++-----------
>  include/linux/mfd/ti_am335x_tscadc.h |  1 +
>  2 files changed, 23 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
> index 30f53cdb41f8..a40091830cea 100644
> --- a/drivers/mfd/ti_am335x_tscadc.c
> +++ b/drivers/mfd/ti_am335x_tscadc.c
> @@ -105,8 +105,9 @@ static void tscadc_idle_config(struct ti_tscadc_dev *tscadc)
>  {
>  	unsigned int idleconfig;
>  
> -	idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
> -			STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
> +	idleconfig = STEPCONFIG_INM_ADCREFM | STEPCONFIG_INP_ADCREFM;
> +	if (tscadc->data->has_tsc)
> +		idleconfig |= STEPCONFIG_YNN | STEPCONFIG_YPN;
>  
>  	regmap_write(tscadc->regmap, REG_IDLECONFIG, idleconfig);
>  }
> @@ -139,11 +140,13 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
>  
>  	tscadc->data = of_device_get_match_data(&pdev->dev);
>  
> -	node = of_get_child_by_name(pdev->dev.of_node, "tsc");
> -	of_property_read_u32(node, "ti,wires", &tscmag_wires);
> -	of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
> -	if (tscmag_wires)
> -		use_tsc = true;
> +	if (tscadc->data->has_tsc) {
> +		node = of_get_child_by_name(pdev->dev.of_node, "tsc");
> +		of_property_read_u32(node, "ti,wires", &tscmag_wires);
> +		of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
> +		if (tscmag_wires)
> +			use_tsc = true;
> +	}
>  
>  	node = of_get_child_by_name(pdev->dev.of_node, "adc");
>  	of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
> @@ -218,15 +221,18 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
>  	regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
>  
>  	/* Set the control register bits */
> -	tscadc->ctrl = CNTRLREG_TSC_STEPCONFIGWRT | CNTRLREG_STEPID;
> -	regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
> +	tscadc->ctrl = CNTRLREG_STEPID;
> +	if (tscadc->data->has_tsc) {
> +		tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT;
> +		regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
> +		if (use_tsc) {
> +			tscadc->ctrl |= CNTRLREG_TSC_ENB;
> +			if (tscmag_wires == 5)
> +				tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
> +			else
> +				tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
> +		}
>  
> -	if (use_tsc) {
> -		tscadc->ctrl |= CNTRLREG_TSC_ENB;
> -		if (tscmag_wires == 5)
> -			tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
> -		else
> -			tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
>  	}
>  
>  	tscadc_idle_config(tscadc);
> @@ -321,6 +327,7 @@ static int __maybe_unused tscadc_resume(struct device *dev)
>  static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume);
>  
>  static const struct ti_tscadc_data tscdata = {
> +	.has_tsc = true,
>  	.name_tscmag = "TI-am335x-tsc",
>  	.compat_tscmag = "ti,am3359-tsc",
>  	.name_adc = "TI-am335x-adc",
> diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
> index d5e2ff8dc84a..082b2af94263 100644
> --- a/include/linux/mfd/ti_am335x_tscadc.h
> +++ b/include/linux/mfd/ti_am335x_tscadc.h
> @@ -163,6 +163,7 @@
>  #define TSCADC_CELLS		2
>  
>  struct ti_tscadc_data {
> +	bool has_tsc;
>  	char *name_tscmag;
>  	char *compat_tscmag;
>  	char *name_adc;