On Fri, 25 Jun 2021 10:43:25 +0300
Alexandru Ardelean <aardelean@xxxxxxxxxxx> wrote:
> The driver tries to initialize all possible regulators from the DT, then
> match the external regulators with each channel and then release all unused
> regulators.
>
> We can change the logic a bit to initialize regulators only when at least
> one channel needs them.
>
> This change creates a mx25_gcq_ext_regulator_setup() function that is
> called only for the external regulators. If there's already a reference to
> an external regulator, the function will just exit early with no error.
>
> This way, the driver doesn't need to keep any track of these regulators
> during init.
>
> Signed-off-by: Alexandru Ardelean <aardelean@xxxxxxxxxxx>
whilst I agree this is a bit cleaner, I definitely want to see review from
those more familiar with the device before I take it!
Thanks,
Jonathan
> ---
> drivers/iio/adc/fsl-imx25-gcq.c | 57 ++++++++++++++++-----------------
> 1 file changed, 28 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c
> index ab5139e911c3..31776f80f847 100644
> --- a/drivers/iio/adc/fsl-imx25-gcq.c
> +++ b/drivers/iio/adc/fsl-imx25-gcq.c
> @@ -172,13 +172,37 @@ static const struct regmap_config mx25_gcq_regconfig = {
> .reg_stride = 4,
> };
>
> +static int mx25_gcq_ext_regulator_setup(struct device *dev,
> + struct mx25_gcq_priv *priv, u32 refp)
> +{
> + char reg_name[12];
> + int ret;
> +
> + if (priv->vref[refp])
> + return 0;
> +
> + ret = snprintf(reg_name, sizeof(reg_name), "vref-%s",
> + mx25_gcq_refp_names[refp]);
> + if (ret < 0)
> + return ret;
> +
> + priv->vref[refp] = devm_regulator_get_optional(dev, reg_name);
> + if (IS_ERR(priv->vref[refp])) {
> + dev_err(dev,
> + "Error, trying to use external voltage reference without a %s regulator.",
> + reg_name);
> + return PTR_ERR(priv->vref[refp]);
> + }
> +
> + return 0;
> +}
> +
> static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
> struct mx25_gcq_priv *priv)
> {
> struct device_node *np = pdev->dev.of_node;
> struct device_node *child;
> struct device *dev = &pdev->dev;
> - unsigned int refp_used[4] = {};
> int ret, i;
>
> /*
> @@ -194,19 +218,6 @@ static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
> MX25_ADCQ_CFG_IN(i) |
> MX25_ADCQ_CFG_REFN_NGND2);
>
> - /*
> - * First get all regulators to store them in channel_vref_mv if
> - * necessary. Later we use that information for proper IIO scale
> - * information.
> - */
> - priv->vref[MX25_ADC_REFP_INT] = NULL;
> - priv->vref[MX25_ADC_REFP_EXT] =
> - devm_regulator_get_optional(&pdev->dev, "vref-ext");
> - priv->vref[MX25_ADC_REFP_XP] =
> - devm_regulator_get_optional(&pdev->dev, "vref-xp");
> - priv->vref[MX25_ADC_REFP_YP] =
> - devm_regulator_get_optional(&pdev->dev, "vref-yp");
> -
> for_each_child_of_node(np, child) {
> u32 reg;
> u32 refp = MX25_ADCQ_CFG_REFP_INT;
> @@ -233,11 +244,10 @@ static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
> case MX25_ADC_REFP_EXT:
> case MX25_ADC_REFP_XP:
> case MX25_ADC_REFP_YP:
> - if (IS_ERR(priv->vref[refp])) {
> - dev_err(dev, "Error, trying to use external voltage reference without a vref-%s regulator.",
> - mx25_gcq_refp_names[refp]);
> + ret = mx25_gcq_ext_regulator_setup(&pdev->dev, priv, refp);
> + if (ret) {
> of_node_put(child);
> - return PTR_ERR(priv->vref[refp]);
> + return ret;
> }
> priv->channel_vref_mv[reg] =
> regulator_get_voltage(priv->vref[refp]);
> @@ -253,8 +263,6 @@ static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
> return -EINVAL;
> }
>
> - ++refp_used[refp];
> -
> /*
> * Shift the read values to the correct positions within the
> * register.
> @@ -285,15 +293,6 @@ static int mx25_gcq_setup_cfgs(struct platform_device *pdev,
> regmap_write(priv->regs, MX25_ADCQ_CR,
> MX25_ADCQ_CR_PDMSK | MX25_ADCQ_CR_QSM_FQS);
>
> - /* Remove unused regulators */
> - for (i = 0; i != 4; ++i) {
> - if (!refp_used[i]) {
> - if (!IS_ERR_OR_NULL(priv->vref[i]))
> - devm_regulator_put(priv->vref[i]);
> - priv->vref[i] = NULL;
> - }
> - }
> -
> return 0;
> }
>
