Re: [PATCH v7 2/7] IIO: Ingenic JZ47xx: Error check clk_enable calls.

Jonathan Cameron
2020-05-19T18:15:41Z

On Sun, 17 May 2020 21:48:59 +0200
Artur Rojek <contact@artur-rojek.eu> wrote:

> Introduce error checks for the clk_enable calls used in this driver.
> As part of the changes, move clk_enable/clk_disable calls out of
> ingenic_adc_set_config and into respective logic of its callers.
>
> Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
> Tested-by: Paul Cercueil <paul@crapouillou.net>

One trivial thing inline.

> ---
>
> Changes:
>
> v6: new patch
>
> v7: no change
>
> drivers/iio/adc/ingenic-adc.c | 23 ++++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c
> index 39c0a609fc94..6c3bbba7c44b 100644
> --- a/drivers/iio/adc/ingenic-adc.c
> +++ b/drivers/iio/adc/ingenic-adc.c
> @@ -73,7 +73,6 @@ static void ingenic_adc_set_config(struct ingenic_adc *adc,
> {
> uint32_t cfg;
>
> - clk_enable(adc->clk);
> mutex_lock(&adc->lock);
>
> cfg = readl(adc->base + JZ_ADC_REG_CFG) & ~mask;
> @@ -81,7 +80,6 @@ static void ingenic_adc_set_config(struct ingenic_adc *adc,
> writel(cfg, adc->base + JZ_ADC_REG_CFG);
>
> mutex_unlock(&adc->lock);
> - clk_disable(adc->clk);
> }
>
> static void ingenic_adc_enable(struct ingenic_adc *adc,
> @@ -124,6 +122,8 @@ static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
> long m)
> {
> struct ingenic_adc *adc = iio_priv(iio_dev);
> + struct device *dev = iio_dev->dev.parent;
> + int ret;
>
> switch (m) {
> case IIO_CHAN_INFO_SCALE:
> @@ -131,6 +131,14 @@ static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
> case INGENIC_ADC_BATTERY:
> if (!adc->soc_data->battery_vref_mode)
> return -EINVAL;
> +
> + ret = clk_enable(adc->clk);
> + if (ret) {
> + dev_err(dev, "Failed to enable clock: %d\n",
> + ret);
> + return ret;
> + }
> +
> if (val > JZ_ADC_BATTERY_LOW_VREF) {
> ingenic_adc_set_config(adc,
> JZ_ADC_REG_CFG_BAT_MD,
> @@ -142,6 +150,9 @@ static int ingenic_adc_write_raw(struct iio_dev *iio_dev,
> JZ_ADC_REG_CFG_BAT_MD);
> adc->low_vref_mode = true;
> }
> +
> + clk_disable(adc->clk);
> +
> return 0;
> default:
> return -EINVAL;
> @@ -317,6 +328,13 @@ static int ingenic_adc_read_chan_info_raw(struct ingenic_adc *adc,
> int *val)
> {
> int bit, ret, engine = (chan->channel == INGENIC_ADC_BATTERY);
> + struct device *dev = iio_priv_to_dev(adc)->dev.parent;
> +
> + ret = clk_enable(adc->clk);
> + if (ret) {
> + dev_err(dev, "Failed to enable clock: %d\n", ret);
> + return ret;
> + }

It almost certainly doesn't matter, but if we are going to move the clk enable
outside the lock, we should do the same with the disable.

>
> /* We cannot sample AUX/AUX2 in parallel. */
> mutex_lock(&adc->aux_lock);
> @@ -325,7 +343,6 @@ static int ingenic_adc_read_chan_info_raw(struct ingenic_adc *adc,
> ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_AUX_MD, bit);
> }
>
> - clk_enable(adc->clk);
> ret = ingenic_adc_capture(adc, engine);
> if (ret)
> goto out;