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    SubjectRe: [PATCH v2 08/11] iio: adc: sun4i-gpadc-iio: add support for A33 thermal sensor
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    Date
    On 10/03/17 10:39, Quentin Schulz wrote:
    > This adds support for the Allwinner A33 thermal sensor.
    >
    > Unlike the A10, A13 and A31, the Allwinner A33 only has one channel
    > which is dedicated to the thermal sensor. Moreover, its thermal sensor
    > does not generate interruptions, thus we only need to directly read the
    > register storing the temperature value.
    >
    > The MFD used by the A10, A13 and A31, was created to avoid breaking the
    > DT binding, but since the nodes for the ADC weren't there for the A33,
    > it is not needed.
    >
    > Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>

    Talk me through why it makes sense to do this rather than simply spin out
    a really simple thermal driver for the A33?

    I'm not against what you have here, but don't feel it has been fully argued.

    Jonathan
    > ---
    >
    > v2:
    > - removed added comments in Kconfig,
    > - simplified Kconfig depends on condition,
    > - removed THERMAL_OF requirement for sun8i,
    > - renamed sun8i_gpadc_channels to sun8i_a33_gpadc_channels,
    > - renamed use_dt boolean in no_irq as it reflects better why we need it,
    > - removed spurious/unneeded modifications done in v1,
    >
    > drivers/iio/adc/Kconfig | 2 +-
    > drivers/iio/adc/sun4i-gpadc-iio.c | 100 ++++++++++++++++++++++++++++++++++++--
    > include/linux/mfd/sun4i-gpadc.h | 4 ++
    > 3 files changed, 102 insertions(+), 4 deletions(-)
    >
    > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
    > index 9f8b4b1..8c8ead6 100644
    > --- a/drivers/iio/adc/Kconfig
    > +++ b/drivers/iio/adc/Kconfig
    > @@ -562,7 +562,7 @@ config STX104
    > config SUN4I_GPADC
    > tristate "Support for the Allwinner SoCs GPADC"
    > depends on IIO
    > - depends on MFD_SUN4I_GPADC
    > + depends on MFD_SUN4I_GPADC || MACH_SUN8I
    > help
    > Say yes here to build support for Allwinner (A10, A13 and A31) SoCs
    > GPADC. This ADC provides 4 channels which can be used as an ADC or as
    > diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
    > index 7cb997a..70684cd 100644
    > --- a/drivers/iio/adc/sun4i-gpadc-iio.c
    > +++ b/drivers/iio/adc/sun4i-gpadc-iio.c
    > @@ -85,6 +85,12 @@ static const struct gpadc_data sun6i_gpadc_data = {
    > .adc_chan_mask = SUN6I_GPADC_CTRL1_ADC_CHAN_MASK,
    > };
    >
    > +static const struct gpadc_data sun8i_a33_gpadc_data = {
    > + .temp_offset = -1662,
    > + .temp_scale = 162,
    > + .tp_mode_en = SUN8I_GPADC_CTRL1_CHOP_TEMP_EN,
    > +};
    > +
    > struct sun4i_gpadc_iio {
    > struct iio_dev *indio_dev;
    > struct completion completion;
    > @@ -96,6 +102,7 @@ struct sun4i_gpadc_iio {
    > unsigned int temp_data_irq;
    > atomic_t ignore_temp_data_irq;
    > const struct gpadc_data *data;
    > + bool no_irq;
    > /* prevents concurrent reads of temperature and ADC */
    > struct mutex mutex;
    > };
    > @@ -138,6 +145,23 @@ static const struct iio_chan_spec sun4i_gpadc_channels_no_temp[] = {
    > SUN4I_GPADC_ADC_CHANNEL(3, "adc_chan3"),
    > };
    >
    > +static const struct iio_chan_spec sun8i_a33_gpadc_channels[] = {
    > + {
    > + .type = IIO_TEMP,
    > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
    > + BIT(IIO_CHAN_INFO_SCALE) |
    > + BIT(IIO_CHAN_INFO_OFFSET),
    > + .datasheet_name = "temp_adc",
    > + },
    > +};
    > +
    > +static const struct regmap_config sun4i_gpadc_regmap_config = {
    > + .reg_bits = 32,
    > + .val_bits = 32,
    > + .reg_stride = 4,
    > + .fast_io = true,
    > +};
    > +
    > static int sun4i_prepare_for_irq(struct iio_dev *indio_dev, int channel,
    > unsigned int irq)
    > {
    > @@ -247,6 +271,17 @@ static int sun4i_gpadc_temp_read(struct iio_dev *indio_dev, int *val)
    > {
    > struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
    >
    > + if (info->no_irq) {
    > + pm_runtime_get_sync(indio_dev->dev.parent);
    > +
    > + regmap_read(info->regmap, SUN4I_GPADC_TEMP_DATA, val);
    > +
    > + pm_runtime_mark_last_busy(indio_dev->dev.parent);
    > + pm_runtime_put_autosuspend(indio_dev->dev.parent);
    > +
    > + return 0;
    > + }
    > +
    > return sun4i_gpadc_read(indio_dev, 0, val, info->temp_data_irq);
    > }
    >
    > @@ -454,6 +489,58 @@ static int sun4i_irq_init(struct platform_device *pdev, const char *name,
    > return 0;
    > }
    >
    > +static const struct of_device_id sun4i_gpadc_of_id[] = {
    > + {
    > + .compatible = "allwinner,sun8i-a33-gpadc-iio",
    > + .data = &sun8i_a33_gpadc_data,
    > + },
    > + { /* sentinel */ }
    > +};
    > +
    > +static int sun4i_gpadc_probe_dt(struct platform_device *pdev,
    > + struct iio_dev *indio_dev)
    > +{
    > + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
    > + const struct of_device_id *of_dev;
    > + struct thermal_zone_device *tzd;
    > + struct resource *mem;
    > + void __iomem *base;
    > + int ret;
    > +
    > + of_dev = of_match_device(sun4i_gpadc_of_id, &pdev->dev);
    > + if (!of_dev)
    > + return -ENODEV;
    > +
    > + info->no_irq = true;
    > + info->data = (struct gpadc_data *)of_dev->data;
    > + indio_dev->num_channels = ARRAY_SIZE(sun8i_a33_gpadc_channels);
    > + indio_dev->channels = sun8i_a33_gpadc_channels;
    > +
    > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    > + base = devm_ioremap_resource(&pdev->dev, mem);
    > + if (IS_ERR(base))
    > + return PTR_ERR(base);
    > +
    > + info->regmap = devm_regmap_init_mmio(&pdev->dev, base,
    > + &sun4i_gpadc_regmap_config);
    > + if (IS_ERR(info->regmap)) {
    > + ret = PTR_ERR(info->regmap);
    > + dev_err(&pdev->dev, "failed to init regmap: %d\n", ret);
    > + return ret;
    > + }
    > +
    > + if (!IS_ENABLED(THERMAL_OF))
    > + return 0;
    > +
    > + tzd = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, info,
    > + &sun4i_ts_tz_ops);
    > + if (IS_ERR(tzd))
    > + dev_err(&pdev->dev, "could not register thermal sensor: %ld\n",
    > + PTR_ERR(tzd));
    > +
    > + return PTR_ERR_OR_ZERO(tzd);
    > +}
    > +
    > static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
    > struct iio_dev *indio_dev)
    > {
    > @@ -462,6 +549,7 @@ static int sun4i_gpadc_probe_mfd(struct platform_device *pdev,
    > dev_get_drvdata(pdev->dev.parent);
    > int ret;
    >
    > + info->no_irq = false;
    > info->regmap = sun4i_gpadc_dev->regmap;
    >
    > indio_dev->num_channels = ARRAY_SIZE(sun4i_gpadc_channels);
    > @@ -561,7 +649,11 @@ static int sun4i_gpadc_probe(struct platform_device *pdev)
    > indio_dev->info = &sun4i_gpadc_iio_info;
    > indio_dev->modes = INDIO_DIRECT_MODE;
    >
    > - ret = sun4i_gpadc_probe_mfd(pdev, indio_dev);
    > + if (pdev->dev.of_node)
    > + ret = sun4i_gpadc_probe_dt(pdev, indio_dev);
    > + else
    > + ret = sun4i_gpadc_probe_mfd(pdev, indio_dev);
    > +
    > if (ret)
    > return ret;
    >
    > @@ -580,7 +672,7 @@ static int sun4i_gpadc_probe(struct platform_device *pdev)
    > return 0;
    >
    > err_map:
    > - if (IS_ENABLED(CONFIG_THERMAL_OF))
    > + if (!info->no_irq && IS_ENABLED(CONFIG_THERMAL_OF))
    > iio_map_array_unregister(indio_dev);
    >
    > pm_runtime_put(&pdev->dev);
    > @@ -592,10 +684,11 @@ static int sun4i_gpadc_probe(struct platform_device *pdev)
    > static int sun4i_gpadc_remove(struct platform_device *pdev)
    > {
    > struct iio_dev *indio_dev = platform_get_drvdata(pdev);
    > + struct sun4i_gpadc_iio *info = iio_priv(indio_dev);
    >
    > pm_runtime_put(&pdev->dev);
    > pm_runtime_disable(&pdev->dev);
    > - if (IS_ENABLED(CONFIG_THERMAL_OF))
    > + if (!info->no_irq && IS_ENABLED(CONFIG_THERMAL_OF))
    > iio_map_array_unregister(indio_dev);
    >
    > return 0;
    > @@ -611,6 +704,7 @@ static const struct platform_device_id sun4i_gpadc_id[] = {
    > static struct platform_driver sun4i_gpadc_driver = {
    > .driver = {
    > .name = "sun4i-gpadc-iio",
    > + .of_match_table = sun4i_gpadc_of_id,
    > .pm = &sun4i_gpadc_pm_ops,
    > },
    > .id_table = sun4i_gpadc_id,
    > diff --git a/include/linux/mfd/sun4i-gpadc.h b/include/linux/mfd/sun4i-gpadc.h
    > index 509e736..139872c 100644
    > --- a/include/linux/mfd/sun4i-gpadc.h
    > +++ b/include/linux/mfd/sun4i-gpadc.h
    > @@ -38,6 +38,10 @@
    > #define SUN6I_GPADC_CTRL1_ADC_CHAN_SELECT(x) (GENMASK(3, 0) & BIT(x))
    > #define SUN6I_GPADC_CTRL1_ADC_CHAN_MASK GENMASK(3, 0)
    >
    > +/* TP_CTRL1 bits for sun8i SoCs */
    > +#define SUN8I_GPADC_CTRL1_CHOP_TEMP_EN BIT(8)
    > +#define SUN8I_GPADC_CTRL1_GPADC_CALI_EN BIT(7)
    > +
    > #define SUN4I_GPADC_CTRL2 0x08
    >
    > #define SUN4I_GPADC_CTRL2_TP_SENSITIVE_ADJUST(x) ((GENMASK(3, 0) & (x)) << 28)
    >

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