iio: adc: meson: fix core clock enable/disable moment

Enable core clock at probe stage and disable it at remove stage.
Core clock is responsible for turning on/off the entire SoC module so
it should be on before the first module register is touched and be off
at very last moment.

Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs")
Signed-off-by: George Stark <gnstark@sberdevices.ru>
Link: https://lore.kernel.org/r/20230721102413.255726-2-gnstark@sberdevices.ru
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index af6bfcc190752e9b674a5294004dcd6a35b51dd0..eb78a6f17fd07c1f40bbf87b66bff245a816a3ae 100644 (file)
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -916,12 +916,6 @@ static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
                goto err_vref;
        }
 
-       ret = clk_prepare_enable(priv->core_clk);
-       if (ret) {
-               dev_err(dev, "failed to enable core clk\n");
-               goto err_core_clk;
-       }
-
        regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
        regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
                           MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
@@ -948,8 +942,6 @@ err_adc_clk:
        regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
                           MESON_SAR_ADC_REG3_ADC_EN, 0);
        meson_sar_adc_set_bandgap(indio_dev, false);
-       clk_disable_unprepare(priv->core_clk);
-err_core_clk:
        regulator_disable(priv->vref);
 err_vref:
        meson_sar_adc_unlock(indio_dev);
@@ -977,8 +969,6 @@ static void meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
 
        meson_sar_adc_set_bandgap(indio_dev, false);
 
-       clk_disable_unprepare(priv->core_clk);
-
        regulator_disable(priv->vref);
 
        if (!ret)
@@ -1211,7 +1201,7 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
        if (IS_ERR(priv->clkin))
                return dev_err_probe(dev, PTR_ERR(priv->clkin), "failed to get clkin\n");
 
-       priv->core_clk = devm_clk_get(dev, "core");
+       priv->core_clk = devm_clk_get_enabled(dev, "core");
        if (IS_ERR(priv->core_clk))
                return dev_err_probe(dev, PTR_ERR(priv->core_clk), "failed to get core clk\n");
 
@@ -1294,15 +1284,26 @@ static int meson_sar_adc_remove(struct platform_device *pdev)
 static int meson_sar_adc_suspend(struct device *dev)
 {
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 
        meson_sar_adc_hw_disable(indio_dev);
 
+       clk_disable_unprepare(priv->core_clk);
+
        return 0;
 }
 
 static int meson_sar_adc_resume(struct device *dev)
 {
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
+       struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
+       int ret;
+
+       ret = clk_prepare_enable(priv->core_clk);
+       if (ret) {
+               dev_err(dev, "failed to enable core clk\n");
+               return ret;
+       }
 
        return meson_sar_adc_hw_enable(indio_dev);
 }