From 9fd243c4fb872381830a9c0ceb5d65a47c0d0e0f Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Mon, 29 May 2017 11:28:17 +0200 Subject: [PATCH] iio: adc: stm32: make core adc clock optional by default 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 Signed-off-by: Jonathan Cameron --- 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 22b7c9321e78..597ab7a5def2 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 @@ err_irq_remove: 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; -- 2.39.5