On Mon, 29 May 2017 11:28:17 +0200
Fabrice Gasnier <fabrice.gasn...@st.com> wrote:
> Analog clock input is mandatory on stm32f4. But newer version of
> ADC hardware block allow to select either bus clock or asynchronous
> clock, for analog circuitry.
>
> So, make it optional by default, but enforce clk presence on stm32f4.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasn...@st.com>
Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/adc/stm32-adc-core.c | 38 ++++++++++++++++++++++++++------------
> 1 file changed, 26 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-adc-core.c
> b/drivers/iio/adc/stm32-adc-core.c
> index 22b7c93..597ab7a 100644
> --- a/drivers/iio/adc/stm32-adc-core.c
> +++ b/drivers/iio/adc/stm32-adc-core.c
> @@ -85,13 +85,21 @@ static int stm32f4_adc_clk_sel(struct platform_device
> *pdev,
> u32 val;
> int i;
>
> + /* stm32f4 has one clk input for analog (mandatory), enforce it here */
> + if (!priv->aclk) {
> + dev_err(&pdev->dev, "No 'adc' clock found\n");
> + return -ENOENT;
> + }
> +
> rate = clk_get_rate(priv->aclk);
> for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) {
> if ((rate / stm32f4_pclk_div[i]) <= STM32F4_ADC_MAX_CLK_RATE)
> break;
> }
> - if (i >= ARRAY_SIZE(stm32f4_pclk_div))
> + if (i >= ARRAY_SIZE(stm32f4_pclk_div)) {
> + dev_err(&pdev->dev, "adc clk selection failed\n");
> return -EINVAL;
> + }
>
> val = readl_relaxed(priv->common.base + STM32F4_ADC_CCR);
> val &= ~STM32F4_ADC_ADCPRE_MASK;
> @@ -227,21 +235,25 @@ static int stm32_adc_probe(struct platform_device *pdev)
> priv->aclk = devm_clk_get(&pdev->dev, "adc");
> if (IS_ERR(priv->aclk)) {
> ret = PTR_ERR(priv->aclk);
> - dev_err(&pdev->dev, "Can't get 'adc' clock\n");
> - goto err_regulator_disable;
> + if (ret == -ENOENT) {
> + priv->aclk = NULL;
> + } else {
> + dev_err(&pdev->dev, "Can't get 'adc' clock\n");
> + goto err_regulator_disable;
> + }
> }
>
> - ret = clk_prepare_enable(priv->aclk);
> - if (ret < 0) {
> - dev_err(&pdev->dev, "adc clk enable failed\n");
> - goto err_regulator_disable;
> + if (priv->aclk) {
> + ret = clk_prepare_enable(priv->aclk);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "adc clk enable failed\n");
> + goto err_regulator_disable;
> + }
> }
>
> ret = stm32f4_adc_clk_sel(pdev, priv);
> - if (ret < 0) {
> - dev_err(&pdev->dev, "adc clk selection failed\n");
> + if (ret < 0)
> goto err_clk_disable;
> - }
>
> ret = stm32_adc_irq_probe(pdev, priv);
> if (ret < 0)
> @@ -261,7 +273,8 @@ static int stm32_adc_probe(struct platform_device *pdev)
> stm32_adc_irq_remove(pdev, priv);
>
> err_clk_disable:
> - clk_disable_unprepare(priv->aclk);
> + if (priv->aclk)
> + clk_disable_unprepare(priv->aclk);
>
> err_regulator_disable:
> regulator_disable(priv->vref);
> @@ -276,7 +289,8 @@ static int stm32_adc_remove(struct platform_device *pdev)
>
> of_platform_depopulate(&pdev->dev);
> stm32_adc_irq_remove(pdev, priv);
> - clk_disable_unprepare(priv->aclk);
> + if (priv->aclk)
> + clk_disable_unprepare(priv->aclk);
> regulator_disable(priv->vref);
>
> return 0;
