Re: [RESEND v4 09/15] iio: adc: aspeed: Use devm_add_action_or_reset.

Jonathan Cameron
2021-08-29T15:24:30Z

On Tue, 24 Aug 2021 17:12:37 +0800
Billy Tsai <billy_tsai@aspeedtech.com> wrote:

> This patch use devm_add_action_or_reset to handle the error in probe
> phase.
>
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
> drivers/iio/adc/aspeed_adc.c | 92 +++++++++++++++++++++---------------
> 1 file changed, 55 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
> index 52db38be9699..1c87e12a0cab 100644
> --- a/drivers/iio/adc/aspeed_adc.c
> +++ b/drivers/iio/adc/aspeed_adc.c
> @@ -187,6 +187,27 @@ static const struct iio_info aspeed_adc_iio_info = {
> .debugfs_reg_access = aspeed_adc_reg_access,
> };
>
> +static void aspeed_adc_unregister_divider(void *data)
> +{
> + struct clk_hw *clk = data;
> +
> + clk_hw_unregister_divider(clk);
> +}
> +
> +static void aspeed_adc_reset_assert(void *data)
> +{
> + struct reset_control *rst = data;
> +
> + reset_control_assert(rst);
> +}
> +
> +static void aspeed_adc_clk_disable_unprepare(void *data)
> +{
> + struct clk *clk = data;
> +
> + clk_disable_unprepare(clk);
> +}
> +
> static int aspeed_adc_vref_config(struct iio_dev *indio_dev)
> {
> struct aspeed_adc_data *data = iio_priv(indio_dev);
> @@ -232,6 +253,12 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> &data->clk_lock);
> if (IS_ERR(data->clk_prescaler))
> return PTR_ERR(data->clk_prescaler);
> +
> + ret = devm_add_action_or_reset(data->dev,
> + aspeed_adc_unregister_divider,
> + data->clk_prescaler);
> + if (ret)
> + return ret;
> snprintf(clk_parent_name, 32, clk_name);
> scaler_flags = CLK_SET_RATE_PARENT;
> }
> @@ -244,23 +271,30 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> &pdev->dev, clk_name, clk_parent_name, scaler_flags,
> data->base + ASPEED_REG_CLOCK_CONTROL, 0,
> data->model_data->scaler_bit_width, 0, &data->clk_lock);
> - if (IS_ERR(data->clk_scaler)) {
> - ret = PTR_ERR(data->clk_scaler);
> - goto scaler_error;
> - }
> + if (IS_ERR(data->clk_scaler))
> + return PTR_ERR(data->clk_scaler);
> +
> + ret = devm_add_action_or_reset(data->dev, aspeed_adc_unregister_divider,
> + data->clk_scaler);
> + if (ret)
> + return ret;
>
> data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> if (IS_ERR(data->rst)) {
> dev_err(&pdev->dev,
> "invalid or missing reset controller device tree entry");
> - ret = PTR_ERR(data->rst);
> - goto reset_error;
> + return PTR_ERR(data->rst);
> }
> reset_control_deassert(data->rst);
>
> + ret = devm_add_action_or_reset(data->dev, aspeed_adc_reset_assert,
> + data->rst);
> + if (ret)
> + return ret;
> +
> ret = aspeed_adc_vref_config(indio_dev);
> if (ret)
> - goto vref_config_error;
> + return ret;
>
> if (data->model_data->wait_init_sequence) {
> /* Enable engine in normal mode. */
> @@ -277,13 +311,19 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> ASPEED_ADC_INIT_POLLING_TIME,
> ASPEED_ADC_INIT_TIMEOUT);
> if (ret)
> - goto poll_timeout_error;
> + return ret;
> }
>
> /* Start all channels in normal mode. */
> ret = clk_prepare_enable(data->clk_scaler->clk);
> if (ret)
> - goto clk_enable_error;
> + return ret;
> +
> + ret = devm_add_action_or_reset(data->dev,
> + aspeed_adc_clk_disable_unprepare,
> + data->clk_scaler->clk);
> + if (ret)
> + return ret;
>
> adc_engine_control_reg_val =
> ASPEED_ADC_CTRL_CHANNEL |
> @@ -299,41 +339,19 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> indio_dev->num_channels = data->model_data->num_channels;
>
> ret = iio_device_register(indio_dev);
> - if (ret)
> - goto iio_register_error;
> -
> + if (ret) {
> + writel(FIELD_PREP(ASPEED_ADC_OP_MODE,
> + ASPEED_ADC_OP_MODE_PWR_DOWN),
> + data->base + ASPEED_REG_ENGINE_CONTROL);
> + return ret;
> + }
> return 0;
> -
> -iio_register_error:
> - writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_PWR_DOWN),
> - data->base + ASPEED_REG_ENGINE_CONTROL);
> - clk_disable_unprepare(data->clk_scaler->clk);
> -clk_enable_error:
> -poll_timeout_error:
> -vref_config_error:
> - reset_control_assert(data->rst);
> -reset_error:
> - clk_hw_unregister_divider(data->clk_scaler);
> -scaler_error:
> - if (data->model_data->need_prescaler)
> - clk_hw_unregister_divider(data->clk_prescaler);
> - return ret;
> }
>
> static int aspeed_adc_remove(struct platform_device *pdev)
> {
> struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> - struct aspeed_adc_data *data = iio_priv(indio_dev);
> -
> iio_device_unregister(indio_dev);

Given there is no longer anything here, you should be safe to call
devm_iio_device_unregister() and get rid of this function entirely.

> - writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_PWR_DOWN),
> - data->base + ASPEED_REG_ENGINE_CONTROL);

Unless I'm missing something this is not handled via any of the
devm_add_action_or_reset() callbacks. You handle it in the error paths manually
but if you move this to managed as well you can drop that handling and still
have it automatically called on remove.

> - clk_disable_unprepare(data->clk_scaler->clk);
> - reset_control_assert(data->rst);
> - clk_hw_unregister_divider(data->clk_scaler);
> - if (data->model_data->need_prescaler)
> - clk_hw_unregister_divider(data->clk_prescaler);
> -
> return 0;
> }
>