On Sat, 25 Mar 2017, Martin Blumenstingl wrote: nitpicking below > Meson GX SoCs however use some magic bits to prevent simultaneous (= > conflicting, because only consumer should use the FIFO buffer with the > ADC results) usage by the Linux kernel and the bootloader (the BL30 > bootloader uses the SAR ADC to read the CPU temperature). > This patch changes guards all BL30 functionality so it is skipped on > SoCs which don't have it. Since the hardware itself doesn't know whether > BL30 is available the internal meson_sar_adc_data is extended so this > information can be provided per of_device_id.data inside the driver. > > Additionally the clocks "adc_clk" and "adc_sel" are not provided by the > clock-controller itself. "adc_sel" is not available at all. "adc_clk" > is provided by the SAR ADC IP block itself on Meson8b (and earlier). > This is already supported by the meson_saradc driver. > > Finally a new of_device_id for the Meson8b SoC is added so it can be > wired up in the corresponding DT. > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> > --- > drivers/iio/adc/meson_saradc.c | 70 +++++++++++++++++++++++++++--------------- > 1 file changed, 46 insertions(+), 24 deletions(-) > > diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c > index dd4190b50df6..f78fe66e0ec8 100644 > --- a/drivers/iio/adc/meson_saradc.c > +++ b/drivers/iio/adc/meson_saradc.c > @@ -220,6 +220,7 @@ enum meson_sar_adc_chan7_mux_sel { > }; > > struct meson_sar_adc_data { > + char has_bl30_integration; bool? > unsigned int resolution; > const char *name; > }; > @@ -437,19 +438,24 @@ static int meson_sar_adc_lock(struct iio_dev *indio_dev) > > mutex_lock(&indio_dev->mlock); > > - /* prevent BL30 from using the SAR ADC while we are using it */ > - regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, > - MESON_SAR_ADC_DELAY_KERNEL_BUSY, > - MESON_SAR_ADC_DELAY_KERNEL_BUSY); > - > - /* wait until BL30 releases it's lock (so we can use the SAR ADC) */ > - do { > - udelay(1); > - regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val); > - } while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--); > - > - if (timeout < 0) > - return -ETIMEDOUT; > + if (priv->data->has_bl30_integration) { > + /* prevent BL30 from using the SAR ADC while we are using it */ > + regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, > + MESON_SAR_ADC_DELAY_KERNEL_BUSY, > + MESON_SAR_ADC_DELAY_KERNEL_BUSY); > + > + /* > + * wait until BL30 releases it's lock (so we can use the SAR its > + * ADC) > + */ > + do { > + udelay(1); > + regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val); > + } while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--); > + > + if (timeout < 0) > + return -ETIMEDOUT; > + } > > return 0; > } > @@ -458,9 +464,10 @@ static void meson_sar_adc_unlock(struct iio_dev *indio_dev) > { > struct meson_sar_adc_priv *priv = iio_priv(indio_dev); > > - /* allow BL30 to use the SAR ADC again */ > - regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, > - MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0); > + if (priv->data->has_bl30_integration) > + /* allow BL30 to use the SAR ADC again */ > + regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY, > + MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0); > > mutex_unlock(&indio_dev->mlock); > } > @@ -614,14 +621,16 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev) > */ > meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT); > > - /* > - * leave sampling delay and the input clocks as configured by BL30 to > - * make sure BL30 gets the values it expects when reading the > - * temperature sensor. > - */ > - regmap_read(priv->regmap, MESON_SAR_ADC_REG3, ®val); > - if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED) > - return 0; > + if (priv->data->has_bl30_integration) { > + /* > + * leave sampling delay and the input clocks as configured by > + * BL30 to make sure BL30 gets the values it expects when > + * reading the temperature sensor. > + */ > + regmap_read(priv->regmap, MESON_SAR_ADC_REG3, ®val); > + if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED) > + return 0; > + } > > meson_sar_adc_stop_sample_engine(indio_dev); > > @@ -834,23 +843,36 @@ static const struct iio_info meson_sar_adc_iio_info = { > .driver_module = THIS_MODULE, > }; > > +struct meson_sar_adc_data meson_sar_adc_meson8b_data = { > + .has_bl30_integration = 0, = false > + .resolution = 10, > + .name = "meson-meson8b-saradc", > +}; > + > struct meson_sar_adc_data meson_sar_adc_gxbb_data = { > + .has_bl30_integration = 1, = true > .resolution = 10, > .name = "meson-gxbb-saradc", > }; > > struct meson_sar_adc_data meson_sar_adc_gxl_data = { > + .has_bl30_integration = 1, > .resolution = 12, > .name = "meson-gxl-saradc", > }; > > struct meson_sar_adc_data meson_sar_adc_gxm_data = { > + .has_bl30_integration = 1, > .resolution = 12, > .name = "meson-gxm-saradc", > }; > > static const struct of_device_id meson_sar_adc_of_match[] = { > { > + .compatible = "amlogic,meson8b-saradc", > + .data = &meson_sar_adc_meson8b_data, > + }, > + { > .compatible = "amlogic,meson-gxbb-saradc", > .data = &meson_sar_adc_gxbb_data, > }, { > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418 -- 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