On Sun, 19 Nov 2017 15:57:01 +0000
Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> On Tue, 31 Oct 2017 21:01:47 +0100
> Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote:
>
> > 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@xxxxxxxxxxxxxx>
>
> I'll go with your opinion on this. We can always request that it is
> added to stable after it has gone in during the next merge window.
>
> Let me know if I seem to have forgotten this once the fixes have
> come back round the loop to my togreg branch.
Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with it.
Thanks,
Jonathan
>
> Thanks,
>
> Jonathan
> > ---
> > drivers/iio/adc/meson_saradc.c | 32 +++++++++++++++++++++++++++++---
> > 1 file changed, 29 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
> > index fa3c1378c2c9..48fb1b642a5e 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)
> > @@ -623,7 +623,7 @@ 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
> > @@ -678,6 +678,32 @@ 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,
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
