diff options
| author | Martin Blumenstingl <martin.blumenstingl@googlemail.com> | 2017-10-31 21:01:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-08 16:03:42 +0100 |
| commit | ab569a4c55422c9fb123e9ce8bffd44198724c51 (patch) | |
| tree | d9a0cb398208a94725ef84818e967b19c50e12f9 /drivers/iio | |
| parent | fda29dbac9e6604f8eeb660953a2bef360514dc7 (diff) | |
iio: adc: meson-saradc: program the channel muxes during initialization
On some Meson8 devices the channel muxes are not programmed. This
results in garbage values when trying to read channels that are not set
up.
Fix this by initializing the channel 0 and 1 muxes in
MESON_SAR_ADC_CHAN_10_SW as well as the muxes for all other channels in
MESON_SAR_ADC_AUX_SW based on what the vendor driver does (which is
simply a 1:1 mapping of channel number and channel mux).
This only showed up on Meson8 devices, because for GXBB and newer BL30
is taking care of initializing the channel muxes.
This additionally fixes a typo in the
MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_MASK macro because the old definition
assumed that the register fields were 2 bit wide, while they are
actually 3 bit wide.
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>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/adc/meson_saradc.c | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c index 24025f179621..29fa7736d80c 100644 --- a/drivers/iio/adc/meson_saradc.c +++ b/drivers/iio/adc/meson_saradc.c @@ -96,8 +96,8 @@ #define MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK GENMASK(11, 0) #define MESON_SAR_ADC_AUX_SW 0x1c - #define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_MASK(_chan) \ - (GENMASK(10, 8) << (((_chan) - 2) * 2)) + #define MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(_chan) \ + (8 + (((_chan) - 2) * 3)) #define MESON_SAR_ADC_AUX_SW_VREF_P_MUX BIT(6) #define MESON_SAR_ADC_AUX_SW_VREF_N_MUX BIT(5) #define MESON_SAR_ADC_AUX_SW_MODE_SEL BIT(4) @@ -622,7 +622,7 @@ static int meson_sar_adc_clk_init(struct iio_dev *indio_dev, static int meson_sar_adc_init(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); - int regval, ret; + int regval, i, ret; /* * make sure we start at CH7 input since the other muxes are only used @@ -677,6 +677,32 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev) FIELD_PREP(MESON_SAR_ADC_DELAY_INPUT_DLY_SEL_MASK, 1)); + /* + * set up the input channel muxes in MESON_SAR_ADC_CHAN_10_SW + * (0 = SAR_ADC_CH0, 1 = SAR_ADC_CH1) + */ + regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK, 0); + regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW, + MESON_SAR_ADC_CHAN_10_SW_CHAN0_MUX_SEL_MASK, + regval); + regval = FIELD_PREP(MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK, 1); + regmap_update_bits(priv->regmap, MESON_SAR_ADC_CHAN_10_SW, + MESON_SAR_ADC_CHAN_10_SW_CHAN1_MUX_SEL_MASK, + regval); + + /* + * set up the input channel muxes in MESON_SAR_ADC_AUX_SW + * (2 = SAR_ADC_CH2, 3 = SAR_ADC_CH3, ...) and enable + * MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW and + * MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW like the vendor driver. + */ + regval = 0; + for (i = 2; i <= 7; i++) + regval |= i << MESON_SAR_ADC_AUX_SW_MUX_SEL_CHAN_SHIFT(i); + regval |= MESON_SAR_ADC_AUX_SW_YP_DRIVE_SW; + regval |= MESON_SAR_ADC_AUX_SW_XP_DRIVE_SW; + regmap_write(priv->regmap, MESON_SAR_ADC_AUX_SW, regval); + ret = clk_set_parent(priv->adc_sel_clk, priv->clkin); if (ret) { dev_err(indio_dev->dev.parent, |