iio: adc: meson-saradc: initialize the bandgap correctly on older SoCs

commit d85eed9f576369bc90322659de96b7dbea1f9a57 upstream.

Meson8 and Meson8b do not have the MESON_SAR_ADC_REG11 register. The
bandgap setting for these SoCs is configured in the
MESON_SAR_ADC_DELTA_10 register instead.
Make the driver aware of this difference and use the correct bandgap
register depending on the SoC.
This has worked fine on Meson8 and Meson8b because the bootloader is
already initializing the bandgap setting.

Fixes: 6c76ed31cd05 ("iio: adc: meson-saradc: add Meson8b SoC compatibility")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 55611244c7991212b177fe54cf7800f522ec1183..abe9df879b2a2867f43521fe68a3fbacd9bdfd9d 100644 (file)
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -221,6 +221,7 @@ enum meson_sar_adc_chan7_mux_sel {
 
 struct meson_sar_adc_data {
        bool                                    has_bl30_integration;
+       u32                                     bandgap_reg;
        unsigned int                            resolution;
        const char                              *name;
 };
@@ -685,6 +686,20 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev)
        return 0;
 }
 
+static void meson_sar_adc_set_bandgap(struct iio_dev *indio_dev, bool on_off)
+{
+       struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
+       u32 enable_mask;
+
+       if (priv->data->bandgap_reg == MESON_SAR_ADC_REG11)
+               enable_mask = MESON_SAR_ADC_REG11_BANDGAP_EN;
+       else
+               enable_mask = MESON_SAR_ADC_DELTA_10_TS_VBG_EN;
+
+       regmap_update_bits(priv->regmap, priv->data->bandgap_reg, enable_mask,
+                          on_off ? enable_mask : 0);
+}
+
 static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
 {
        struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
@@ -717,9 +732,9 @@ static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
        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);
-       regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
-                          MESON_SAR_ADC_REG11_BANDGAP_EN,
-                          MESON_SAR_ADC_REG11_BANDGAP_EN);
+
+       meson_sar_adc_set_bandgap(indio_dev, true);
+
        regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
                           MESON_SAR_ADC_REG3_ADC_EN,
                           MESON_SAR_ADC_REG3_ADC_EN);
@@ -739,8 +754,7 @@ static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
 err_adc_clk:
        regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
                           MESON_SAR_ADC_REG3_ADC_EN, 0);
-       regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
-                          MESON_SAR_ADC_REG11_BANDGAP_EN, 0);
+       meson_sar_adc_set_bandgap(indio_dev, false);
        clk_disable_unprepare(priv->sana_clk);
 err_sana_clk:
        clk_disable_unprepare(priv->core_clk);
@@ -765,8 +779,8 @@ static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
 
        regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG3,
                           MESON_SAR_ADC_REG3_ADC_EN, 0);
-       regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
-                          MESON_SAR_ADC_REG11_BANDGAP_EN, 0);
+
+       meson_sar_adc_set_bandgap(indio_dev, false);
 
        clk_disable_unprepare(priv->sana_clk);
        clk_disable_unprepare(priv->core_clk);
@@ -845,30 +859,35 @@ static const struct iio_info meson_sar_adc_iio_info = {
 
 static const struct meson_sar_adc_data meson_sar_adc_meson8_data = {
        .has_bl30_integration = false,
+       .bandgap_reg = MESON_SAR_ADC_DELTA_10,
        .resolution = 10,
        .name = "meson-meson8-saradc",
 };
 
 static const struct meson_sar_adc_data meson_sar_adc_meson8b_data = {
        .has_bl30_integration = false,
+       .bandgap_reg = MESON_SAR_ADC_DELTA_10,
        .resolution = 10,
        .name = "meson-meson8b-saradc",
 };
 
 static const struct meson_sar_adc_data meson_sar_adc_gxbb_data = {
        .has_bl30_integration = true,
+       .bandgap_reg = MESON_SAR_ADC_REG11,
        .resolution = 10,
        .name = "meson-gxbb-saradc",
 };
 
 static const struct meson_sar_adc_data meson_sar_adc_gxl_data = {
        .has_bl30_integration = true,
+       .bandgap_reg = MESON_SAR_ADC_REG11,
        .resolution = 12,
        .name = "meson-gxl-saradc",
 };
 
 static const struct meson_sar_adc_data meson_sar_adc_gxm_data = {
        .has_bl30_integration = true,
+       .bandgap_reg = MESON_SAR_ADC_REG11,
        .resolution = 12,
        .name = "meson-gxm-saradc",
 };