| Message ID | 20210808015659.2955443-4-liambeguin@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | AD7949 Fixes | expand |
On Sat, 7 Aug 2021 21:56:57 -0400 Liam Beguin <liambeguin@gmail.com> wrote: > From: Liam Beguin <lvb@xiphos.com> > > Add support for selecting a custom reference voltage from the > devicetree. If an external source is used, a vref regulator should be > defined in the devicetree. > > Signed-off-by: Liam Beguin <lvb@xiphos.com> Hi Liam, I'm not sure the parsing of the child nodes will work if using an external reference. See below. Jonathan > --- > drivers/iio/adc/ad7949.c | 140 ++++++++++++++++++++++++++++++++++----- > 1 file changed, 122 insertions(+), 18 deletions(-) > > diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c > index 3f94ae639a44..14a7c79d637e 100644 > --- a/drivers/iio/adc/ad7949.c > +++ b/drivers/iio/adc/ad7949.c > @@ -35,7 +35,11 @@ > > /* REF: reference/buffer selection */ > #define AD7949_CFG_BIT_REF GENMASK(5, 3) > -#define AD7949_CFG_VAL_REF_EXT_BUF 7 > +#define AD7949_CFG_VAL_REF_EXT_TEMP_BUF 3 > +#define AD7949_CFG_VAL_REF_EXT_TEMP 2 > +#define AD7949_CFG_VAL_REF_INT_4096 1 > +#define AD7949_CFG_VAL_REF_INT_2500 0 > +#define AD7949_CFG_VAL_REF_EXTERNAL BIT(1) > > /* SEQ: channel sequencer. Allows for scanning channels */ > #define AD7949_CFG_BIT_SEQ GENMASK(2, 1) > @@ -60,6 +64,14 @@ static const struct ad7949_adc_spec ad7949_adc_spec[] = { > [ID_AD7689] = { .num_channels = 8, .resolution = 16 }, > }; > > +/** > + * struct ad7949_channel - ADC Channel parameters > + * @refsel: reference selection > + */ > +struct ad7949_channel { > + u32 refsel; > +}; > + > /** > * struct ad7949_adc_chip - AD ADC chip > * @lock: protects write sequences > @@ -78,6 +90,7 @@ struct ad7949_adc_chip { > struct regulator *vref; > struct iio_dev *indio_dev; > struct spi_device *spi; > + struct ad7949_channel *channels; > u8 resolution; > u8 bits_per_word; > u16 cfg; > @@ -136,6 +149,7 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, > int ret; > int i; > struct spi_message msg; > + struct ad7949_channel *ad7949_chan = &ad7949_adc->channels[channel]; > struct spi_transfer tx[] = { > { > .len = 2, > @@ -156,8 +170,9 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, > */ > for (i = 0; i < 2; i++) { > ret = ad7949_spi_write_cfg(ad7949_adc, > - FIELD_PREP(AD7949_CFG_BIT_INX, channel), > - AD7949_CFG_BIT_INX); > + FIELD_PREP(AD7949_CFG_BIT_INX, channel) | > + FIELD_PREP(AD7949_CFG_BIT_REF, ad7949_chan->refsel), > + AD7949_CFG_BIT_INX | AD7949_CFG_BIT_REF); > if (ret) > return ret; > if (channel == ad7949_adc->current_channel) > @@ -225,6 +240,7 @@ static int ad7949_spi_read_raw(struct iio_dev *indio_dev, > int *val, int *val2, long mask) > { > struct ad7949_adc_chip *ad7949_adc = iio_priv(indio_dev); > + struct ad7949_channel *ad7949_chan = &ad7949_adc->channels[chan->channel]; > int ret; > > if (!val) > @@ -242,12 +258,26 @@ static int ad7949_spi_read_raw(struct iio_dev *indio_dev, > return IIO_VAL_INT; > > case IIO_CHAN_INFO_SCALE: > - ret = regulator_get_voltage(ad7949_adc->vref); > - if (ret < 0) > - return ret; > + switch (ad7949_chan->refsel) { > + case AD7949_CFG_VAL_REF_INT_2500: > + *val = 2500; > + break; > + case AD7949_CFG_VAL_REF_INT_4096: > + *val = 4096; > + break; > + case AD7949_CFG_VAL_REF_EXT_TEMP: > + case AD7949_CFG_VAL_REF_EXT_TEMP_BUF: > + ret = regulator_get_voltage(ad7949_adc->vref); > + if (ret < 0) > + return ret; > + > + /* convert value back to mV */ > + *val = ret / 1000; > + break; > + } > > - *val = ret / 5000; > - return IIO_VAL_INT; > + *val2 = (1 << ad7949_adc->resolution) - 1; > + return IIO_VAL_FRACTIONAL; > } > > return -EINVAL; > @@ -286,7 +316,7 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc) > FIELD_PREP(AD7949_CFG_BIT_INCC, AD7949_CFG_VAL_INCC_UNIPOLAR_GND) | > FIELD_PREP(AD7949_CFG_BIT_INX, ad7949_adc->current_channel) | > FIELD_PREP(AD7949_CFG_BIT_BW_FULL, 1) | > - FIELD_PREP(AD7949_CFG_BIT_REF, AD7949_CFG_VAL_REF_EXT_BUF) | > + FIELD_PREP(AD7949_CFG_BIT_REF, ad7949_adc->channels[0].refsel) | > FIELD_PREP(AD7949_CFG_BIT_SEQ, 0x0) | > FIELD_PREP(AD7949_CFG_BIT_RBN, 1); > > @@ -302,14 +332,24 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc) > return ret; > } > > +static void ad7949_disable_reg(void *reg) > +{ > + regulator_disable(reg); > +} > + > static int ad7949_spi_probe(struct spi_device *spi) > { > u32 spi_ctrl_mask = spi->controller->bits_per_word_mask; > struct device *dev = &spi->dev; > const struct ad7949_adc_spec *spec; > struct ad7949_adc_chip *ad7949_adc; > + struct ad7949_channel *ad7949_chan; > + struct fwnode_handle *child; > struct iio_dev *indio_dev; > + int mode; > + u32 tmp; > int ret; > + int i; > > indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc)); > if (!indio_dev) { > @@ -343,16 +383,82 @@ static int ad7949_spi_probe(struct spi_device *spi) > return -EINVAL; > } > > - ad7949_adc->vref = devm_regulator_get(dev, "vref"); > + /* Setup external voltage ref, buffered? */ > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin"); > if (IS_ERR(ad7949_adc->vref)) { > - dev_err(dev, "fail to request regulator\n"); > - return PTR_ERR(ad7949_adc->vref); > + ret = PTR_ERR(ad7949_adc->vref); > + if (ret != -ENODEV) > + return ret; > + /* unbuffered? */ > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vref"); > + if (IS_ERR(ad7949_adc->vref)) { > + ret = PTR_ERR(ad7949_adc->vref); > + if (ret != -ENODEV) > + return ret; > + /* Internal then */ > + mode = AD7949_CFG_VAL_REF_INT_4096; > + } else { > + mode = AD7949_CFG_VAL_REF_EXT_TEMP; > + } > + } else { > + mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; > } > > - ret = regulator_enable(ad7949_adc->vref); > - if (ret < 0) { > - dev_err(dev, "fail to enable regulator\n"); > - return ret; > + if (mode & AD7949_CFG_VAL_REF_EXTERNAL) { > + ret = regulator_enable(ad7949_adc->vref); > + if (ret < 0) { > + dev_err(dev, "fail to enable regulator\n"); > + return ret; > + } > + > + ret = devm_add_action_or_reset(dev, ad7949_disable_reg, > + ad7949_adc->vref); > + if (ret) > + return ret; > + } > + > + ad7949_adc->channels = devm_kcalloc(dev, spec->num_channels, > + sizeof(*ad7949_adc->channels), > + GFP_KERNEL); > + if (!ad7949_adc->channels) { > + dev_err(dev, "unable to allocate ADC channels\n"); > + return -ENOMEM; > + } > + > + /* Initialize all channel structures */ > + for (i = 0; i < spec->num_channels; i++) > + ad7949_adc->channels[i].refsel = mode; > + > + /* Read channel specific information form the devicetree */ > + device_for_each_child_node(dev, child) { > + ret = fwnode_property_read_u32(child, "reg", &i); > + if (ret) { > + dev_err(dev, "missing reg property in %pfw\n", child); > + fwnode_handle_put(child); > + return ret; > + } > + > + ad7949_chan = &ad7949_adc->channels[i]; > + > + ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > + if (ret < 0 && ret != -EINVAL) { > + dev_err(dev, "invalid internal reference in %pfw\n", child); > + fwnode_handle_put(child); > + return ret; > + } So if we are using external voltage, then we'd not expect this to exist. ret != -EINVAL should deal with that. However, we then hit the following switch and temp isn't set to an appropriate value so we get the error. Am I missing something? > + > + switch (tmp) { > + case 2500000: > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_2500; > + break; > + case 4096000: > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_4096; > + break; > + default: > + dev_err(dev, "unsupported internal voltage reference\n"); > + fwnode_handle_put(child); > + return -EINVAL; > + } > } > > mutex_init(&ad7949_adc->lock); > @@ -373,7 +479,6 @@ static int ad7949_spi_probe(struct spi_device *spi) > > err: > mutex_destroy(&ad7949_adc->lock); > - regulator_disable(ad7949_adc->vref); > > return ret; > } > @@ -385,7 +490,6 @@ static int ad7949_spi_remove(struct spi_device *spi) > > iio_device_unregister(indio_dev); > mutex_destroy(&ad7949_adc->lock); > - regulator_disable(ad7949_adc->vref); > > return 0; > }
On Sun Aug 8, 2021 at 12:36 PM EDT, Jonathan Cameron wrote: > On Sat, 7 Aug 2021 21:56:57 -0400 > Liam Beguin <liambeguin@gmail.com> wrote: > > > From: Liam Beguin <lvb@xiphos.com> > > > > Add support for selecting a custom reference voltage from the > > devicetree. If an external source is used, a vref regulator should be > > defined in the devicetree. > > > > Signed-off-by: Liam Beguin <lvb@xiphos.com> > > Hi Liam, I'm not sure the parsing of the child nodes will work if using > an external reference. See below. > > Jonathan > > > --- > > drivers/iio/adc/ad7949.c | 140 ++++++++++++++++++++++++++++++++++----- > > 1 file changed, 122 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c > > index 3f94ae639a44..14a7c79d637e 100644 > > --- a/drivers/iio/adc/ad7949.c > > +++ b/drivers/iio/adc/ad7949.c > > @@ -35,7 +35,11 @@ > > > > /* REF: reference/buffer selection */ > > #define AD7949_CFG_BIT_REF GENMASK(5, 3) > > -#define AD7949_CFG_VAL_REF_EXT_BUF 7 > > +#define AD7949_CFG_VAL_REF_EXT_TEMP_BUF 3 > > +#define AD7949_CFG_VAL_REF_EXT_TEMP 2 > > +#define AD7949_CFG_VAL_REF_INT_4096 1 > > +#define AD7949_CFG_VAL_REF_INT_2500 0 > > +#define AD7949_CFG_VAL_REF_EXTERNAL BIT(1) > > > > /* SEQ: channel sequencer. Allows for scanning channels */ > > #define AD7949_CFG_BIT_SEQ GENMASK(2, 1) > > @@ -60,6 +64,14 @@ static const struct ad7949_adc_spec ad7949_adc_spec[] = { > > [ID_AD7689] = { .num_channels = 8, .resolution = 16 }, > > }; > > > > +/** > > + * struct ad7949_channel - ADC Channel parameters > > + * @refsel: reference selection > > + */ > > +struct ad7949_channel { > > + u32 refsel; > > +}; > > + > > /** > > * struct ad7949_adc_chip - AD ADC chip > > * @lock: protects write sequences > > @@ -78,6 +90,7 @@ struct ad7949_adc_chip { > > struct regulator *vref; > > struct iio_dev *indio_dev; > > struct spi_device *spi; > > + struct ad7949_channel *channels; > > u8 resolution; > > u8 bits_per_word; > > u16 cfg; > > @@ -136,6 +149,7 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, > > int ret; > > int i; > > struct spi_message msg; > > + struct ad7949_channel *ad7949_chan = &ad7949_adc->channels[channel]; > > struct spi_transfer tx[] = { > > { > > .len = 2, > > @@ -156,8 +170,9 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, > > */ > > for (i = 0; i < 2; i++) { > > ret = ad7949_spi_write_cfg(ad7949_adc, > > - FIELD_PREP(AD7949_CFG_BIT_INX, channel), > > - AD7949_CFG_BIT_INX); > > + FIELD_PREP(AD7949_CFG_BIT_INX, channel) | > > + FIELD_PREP(AD7949_CFG_BIT_REF, ad7949_chan->refsel), > > + AD7949_CFG_BIT_INX | AD7949_CFG_BIT_REF); > > if (ret) > > return ret; > > if (channel == ad7949_adc->current_channel) > > @@ -225,6 +240,7 @@ static int ad7949_spi_read_raw(struct iio_dev *indio_dev, > > int *val, int *val2, long mask) > > { > > struct ad7949_adc_chip *ad7949_adc = iio_priv(indio_dev); > > + struct ad7949_channel *ad7949_chan = &ad7949_adc->channels[chan->channel]; > > int ret; > > > > if (!val) > > @@ -242,12 +258,26 @@ static int ad7949_spi_read_raw(struct iio_dev *indio_dev, > > return IIO_VAL_INT; > > > > case IIO_CHAN_INFO_SCALE: > > - ret = regulator_get_voltage(ad7949_adc->vref); > > - if (ret < 0) > > - return ret; > > + switch (ad7949_chan->refsel) { > > + case AD7949_CFG_VAL_REF_INT_2500: > > + *val = 2500; > > + break; > > + case AD7949_CFG_VAL_REF_INT_4096: > > + *val = 4096; > > + break; > > + case AD7949_CFG_VAL_REF_EXT_TEMP: > > + case AD7949_CFG_VAL_REF_EXT_TEMP_BUF: > > + ret = regulator_get_voltage(ad7949_adc->vref); > > + if (ret < 0) > > + return ret; > > + > > + /* convert value back to mV */ > > + *val = ret / 1000; > > + break; > > + } > > > > - *val = ret / 5000; > > - return IIO_VAL_INT; > > + *val2 = (1 << ad7949_adc->resolution) - 1; > > + return IIO_VAL_FRACTIONAL; > > } > > > > return -EINVAL; > > @@ -286,7 +316,7 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc) > > FIELD_PREP(AD7949_CFG_BIT_INCC, AD7949_CFG_VAL_INCC_UNIPOLAR_GND) | > > FIELD_PREP(AD7949_CFG_BIT_INX, ad7949_adc->current_channel) | > > FIELD_PREP(AD7949_CFG_BIT_BW_FULL, 1) | > > - FIELD_PREP(AD7949_CFG_BIT_REF, AD7949_CFG_VAL_REF_EXT_BUF) | > > + FIELD_PREP(AD7949_CFG_BIT_REF, ad7949_adc->channels[0].refsel) | > > FIELD_PREP(AD7949_CFG_BIT_SEQ, 0x0) | > > FIELD_PREP(AD7949_CFG_BIT_RBN, 1); > > > > @@ -302,14 +332,24 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc) > > return ret; > > } > > > > +static void ad7949_disable_reg(void *reg) > > +{ > > + regulator_disable(reg); > > +} > > + > > static int ad7949_spi_probe(struct spi_device *spi) > > { > > u32 spi_ctrl_mask = spi->controller->bits_per_word_mask; > > struct device *dev = &spi->dev; > > const struct ad7949_adc_spec *spec; > > struct ad7949_adc_chip *ad7949_adc; > > + struct ad7949_channel *ad7949_chan; > > + struct fwnode_handle *child; > > struct iio_dev *indio_dev; > > + int mode; > > + u32 tmp; > > int ret; > > + int i; > > > > indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc)); > > if (!indio_dev) { > > @@ -343,16 +383,82 @@ static int ad7949_spi_probe(struct spi_device *spi) > > return -EINVAL; > > } > > > > - ad7949_adc->vref = devm_regulator_get(dev, "vref"); > > + /* Setup external voltage ref, buffered? */ > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin"); > > if (IS_ERR(ad7949_adc->vref)) { > > - dev_err(dev, "fail to request regulator\n"); > > - return PTR_ERR(ad7949_adc->vref); > > + ret = PTR_ERR(ad7949_adc->vref); > > + if (ret != -ENODEV) > > + return ret; > > + /* unbuffered? */ > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vref"); > > + if (IS_ERR(ad7949_adc->vref)) { > > + ret = PTR_ERR(ad7949_adc->vref); > > + if (ret != -ENODEV) > > + return ret; > > + /* Internal then */ > > + mode = AD7949_CFG_VAL_REF_INT_4096; > > + } else { > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP; > > + } > > + } else { > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; > > } > > > > - ret = regulator_enable(ad7949_adc->vref); > > - if (ret < 0) { > > - dev_err(dev, "fail to enable regulator\n"); > > - return ret; > > + if (mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > + ret = regulator_enable(ad7949_adc->vref); > > + if (ret < 0) { > > + dev_err(dev, "fail to enable regulator\n"); > > + return ret; > > + } > > + > > + ret = devm_add_action_or_reset(dev, ad7949_disable_reg, > > + ad7949_adc->vref); > > + if (ret) > > + return ret; > > + } > > + > > + ad7949_adc->channels = devm_kcalloc(dev, spec->num_channels, > > + sizeof(*ad7949_adc->channels), > > + GFP_KERNEL); > > + if (!ad7949_adc->channels) { > > + dev_err(dev, "unable to allocate ADC channels\n"); > > + return -ENOMEM; > > + } > > + > > + /* Initialize all channel structures */ > > + for (i = 0; i < spec->num_channels; i++) > > + ad7949_adc->channels[i].refsel = mode; > > + > > + /* Read channel specific information form the devicetree */ > > + device_for_each_child_node(dev, child) { > > + ret = fwnode_property_read_u32(child, "reg", &i); > > + if (ret) { > > + dev_err(dev, "missing reg property in %pfw\n", child); > > + fwnode_handle_put(child); > > + return ret; > > + } > > + > > + ad7949_chan = &ad7949_adc->channels[i]; > > + > > + ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > + if (ret < 0 && ret != -EINVAL) { > > + dev_err(dev, "invalid internal reference in %pfw\n", child); > > + fwnode_handle_put(child); > > + return ret; > > + } Hi Jonathan, > > So if we are using external voltage, then we'd not expect this to exist. > ret != -EINVAL should deal with that. However, we then hit the following > switch > and temp isn't set to an appropriate value so we get the error. > > Am I missing something? You're right that using an external reference, will cause this to fail. My apologies, I've done a poor job of testing the last two revisions of this patch. I'll do better. Since a regulator is also required when we're using an external source, I'll add a check for that. Something like this: ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { continue; } else if (ret < 0) { dev_err(dev, "invalid voltage reference in %pfw\n", child); fwnode_handle_put(child); return ret; } Given that we can now have a different scale for each channel based on the vref source, should BIT(IIO_CHAN_INFO_SCALE) be moved to .info_mask_separate in the channel definition? Thanks, Liam > > > + > > + switch (tmp) { > > + case 2500000: > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_2500; > > + break; > > + case 4096000: > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_4096; > > + break; > > + default: > > + dev_err(dev, "unsupported internal voltage reference\n"); > > + fwnode_handle_put(child); > > + return -EINVAL; > > + } > > } > > > > mutex_init(&ad7949_adc->lock); > > @@ -373,7 +479,6 @@ static int ad7949_spi_probe(struct spi_device *spi) > > > > err: > > mutex_destroy(&ad7949_adc->lock); > > - regulator_disable(ad7949_adc->vref); > > > > return ret; > > } > > @@ -385,7 +490,6 @@ static int ad7949_spi_remove(struct spi_device *spi) > > > > iio_device_unregister(indio_dev); > > mutex_destroy(&ad7949_adc->lock); > > - regulator_disable(ad7949_adc->vref); > > > > return 0; > > }
... > + > > > static int ad7949_spi_probe(struct spi_device *spi) > > > { > > > u32 spi_ctrl_mask = spi->controller->bits_per_word_mask; > > > struct device *dev = &spi->dev; > > > const struct ad7949_adc_spec *spec; > > > struct ad7949_adc_chip *ad7949_adc; > > > + struct ad7949_channel *ad7949_chan; > > > + struct fwnode_handle *child; > > > struct iio_dev *indio_dev; > > > + int mode; > > > + u32 tmp; > > > int ret; > > > + int i; > > > > > > indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc)); > > > if (!indio_dev) { > > > @@ -343,16 +383,82 @@ static int ad7949_spi_probe(struct spi_device *spi) > > > return -EINVAL; > > > } > > > > > > - ad7949_adc->vref = devm_regulator_get(dev, "vref"); > > > + /* Setup external voltage ref, buffered? */ > > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin"); > > > if (IS_ERR(ad7949_adc->vref)) { > > > - dev_err(dev, "fail to request regulator\n"); > > > - return PTR_ERR(ad7949_adc->vref); > > > + ret = PTR_ERR(ad7949_adc->vref); > > > + if (ret != -ENODEV) > > > + return ret; > > > + /* unbuffered? */ > > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vref"); > > > + if (IS_ERR(ad7949_adc->vref)) { > > > + ret = PTR_ERR(ad7949_adc->vref); > > > + if (ret != -ENODEV) > > > + return ret; > > > + /* Internal then */ > > > + mode = AD7949_CFG_VAL_REF_INT_4096; > > > + } else { > > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP; > > > + } > > > + } else { > > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; > > > } > > > > > > - ret = regulator_enable(ad7949_adc->vref); > > > - if (ret < 0) { > > > - dev_err(dev, "fail to enable regulator\n"); > > > - return ret; > > > + if (mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > > + ret = regulator_enable(ad7949_adc->vref); > > > + if (ret < 0) { > > > + dev_err(dev, "fail to enable regulator\n"); > > > + return ret; > > > + } > > > + > > > + ret = devm_add_action_or_reset(dev, ad7949_disable_reg, > > > + ad7949_adc->vref); > > > + if (ret) > > > + return ret; > > > + } > > > + > > > + ad7949_adc->channels = devm_kcalloc(dev, spec->num_channels, > > > + sizeof(*ad7949_adc->channels), > > > + GFP_KERNEL); > > > + if (!ad7949_adc->channels) { > > > + dev_err(dev, "unable to allocate ADC channels\n"); > > > + return -ENOMEM; > > > + } > > > + > > > + /* Initialize all channel structures */ > > > + for (i = 0; i < spec->num_channels; i++) > > > + ad7949_adc->channels[i].refsel = mode; > > > + > > > + /* Read channel specific information form the devicetree */ > > > + device_for_each_child_node(dev, child) { > > > + ret = fwnode_property_read_u32(child, "reg", &i); > > > + if (ret) { > > > + dev_err(dev, "missing reg property in %pfw\n", child); > > > + fwnode_handle_put(child); > > > + return ret; > > > + } > > > + > > > + ad7949_chan = &ad7949_adc->channels[i]; > > > + > > > + ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > > + if (ret < 0 && ret != -EINVAL) { > > > + dev_err(dev, "invalid internal reference in %pfw\n", child); > > > + fwnode_handle_put(child); > > > + return ret; > > > + } > > Hi Jonathan, > > > > > So if we are using external voltage, then we'd not expect this to exist. > > ret != -EINVAL should deal with that. However, we then hit the following > > switch > > and temp isn't set to an appropriate value so we get the error. > > > > Am I missing something? > > You're right that using an external reference, will cause this to fail. > My apologies, I've done a poor job of testing the last two revisions of > this patch. I'll do better. > > Since a regulator is also required when we're using an external source, > I'll add a check for that. Something like this: > > ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { > continue; > } else if (ret < 0) { > dev_err(dev, "invalid voltage reference in %pfw\n", child); > fwnode_handle_put(child); > return ret; > } Makes sense. > > Given that we can now have a different scale for each channel based on > the vref source, should BIT(IIO_CHAN_INFO_SCALE) be moved to > .info_mask_separate in the channel definition? Yes, good point. Hopefully no one will notice the ABI change *crosses fingers*. Jonathan > > Thanks, > Liam > > > > > > + > > > + switch (tmp) { > > > + case 2500000: > > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_2500; > > > + break; > > > + case 4096000: > > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_4096; > > > + break; > > > + default: > > > + dev_err(dev, "unsupported internal voltage reference\n"); > > > + fwnode_handle_put(child); > > > + return -EINVAL; > > > + } > > > } > > > > > > mutex_init(&ad7949_adc->lock); > > > @@ -373,7 +479,6 @@ static int ad7949_spi_probe(struct spi_device *spi) > > > > > > err: > > > mutex_destroy(&ad7949_adc->lock); > > > - regulator_disable(ad7949_adc->vref); > > > > > > return ret; > > > } > > > @@ -385,7 +490,6 @@ static int ad7949_spi_remove(struct spi_device *spi) > > > > > > iio_device_unregister(indio_dev); > > > mutex_destroy(&ad7949_adc->lock); > > > - regulator_disable(ad7949_adc->vref); > > > > > > return 0; > > > } >
On Mon, Aug 9, 2021 at 1:50 AM Liam Beguin <liambeguin@gmail.com> wrote: > On Sun Aug 8, 2021 at 12:36 PM EDT, Jonathan Cameron wrote: > > On Sat, 7 Aug 2021 21:56:57 -0400 > ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { > continue; > } else if (ret < 0) { Side note, redundant 'else' > dev_err(dev, "invalid voltage reference in %pfw\n", child); > fwnode_handle_put(child); > return ret; > }
On Tue Aug 10, 2021 at 8:15 AM EDT, Andy Shevchenko wrote: > On Mon, Aug 9, 2021 at 1:50 AM Liam Beguin <liambeguin@gmail.com> wrote: > > On Sun Aug 8, 2021 at 12:36 PM EDT, Jonathan Cameron wrote: > > > On Sat, 7 Aug 2021 21:56:57 -0400 > > ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > continue; > > > } else if (ret < 0) { > Hi Andy, > Side note, redundant 'else' Are you asking to add an 'else' statement? because, unless I'm mistaken, in this case ret can have other negative values that we want to catch with this 'else if'. Thanks for your time, Liam > > > dev_err(dev, "invalid voltage reference in %pfw\n", child); > > fwnode_handle_put(child); > > return ret; > > } > > > -- > With Best Regards, > Andy Shevchenko
On Tue, Aug 10, 2021 at 10:46 PM Liam Beguin <liambeguin@gmail.com> wrote: > On Tue Aug 10, 2021 at 8:15 AM EDT, Andy Shevchenko wrote: > > On Mon, Aug 9, 2021 at 1:50 AM Liam Beguin <liambeguin@gmail.com> wrote: > > > On Sun Aug 8, 2021 at 12:36 PM EDT, Jonathan Cameron wrote: > > > > On Sat, 7 Aug 2021 21:56:57 -0400 > > > ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > > if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > > continue; > > > > > } else if (ret < 0) { > > Side note, redundant 'else' > > Are you asking to add an 'else' statement? > > because, unless I'm mistaken, in this case ret can have other negative values > that we want to catch with this 'else if'. You lost me, I have no idea what "to add" and "other" mean here. No, I asked to remove it. It's redundant. > > > dev_err(dev, "invalid voltage reference in %pfw\n", child); > > > fwnode_handle_put(child); > > > return ret; > > > }
On Tue Aug 10, 2021 at 3:55 PM EDT, Andy Shevchenko wrote: > On Tue, Aug 10, 2021 at 10:46 PM Liam Beguin <liambeguin@gmail.com> > wrote: > > On Tue Aug 10, 2021 at 8:15 AM EDT, Andy Shevchenko wrote: > > > On Mon, Aug 9, 2021 at 1:50 AM Liam Beguin <liambeguin@gmail.com> wrote: > > > > On Sun Aug 8, 2021 at 12:36 PM EDT, Jonathan Cameron wrote: > > > > > On Sat, 7 Aug 2021 21:56:57 -0400 > > > > ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > > > if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > > > continue; > > > > > > > } else if (ret < 0) { > > > > Side note, redundant 'else' > > > > Are you asking to add an 'else' statement? > > > > because, unless I'm mistaken, in this case ret can have other negative values > > that we want to catch with this 'else if'. > > You lost me, I have no idea what "to add" and "other" mean here. No, I > asked to remove it. It's redundant. > Oh, I see what you meant now. I'll fix it. Thanks! Liam > > > > dev_err(dev, "invalid voltage reference in %pfw\n", child); > > > > fwnode_handle_put(child); > > > > return ret; > > > > } > > -- > With Best Regards, > Andy Shevchenko
On Mon Aug 9, 2021 at 3:42 PM EDT, Jonathan Cameron wrote: > ... > > + > > > > static int ad7949_spi_probe(struct spi_device *spi) > > > > { > > > > u32 spi_ctrl_mask = spi->controller->bits_per_word_mask; > > > > struct device *dev = &spi->dev; > > > > const struct ad7949_adc_spec *spec; > > > > struct ad7949_adc_chip *ad7949_adc; > > > > + struct ad7949_channel *ad7949_chan; > > > > + struct fwnode_handle *child; > > > > struct iio_dev *indio_dev; > > > > + int mode; > > > > + u32 tmp; > > > > int ret; > > > > + int i; > > > > > > > > indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc)); > > > > if (!indio_dev) { > > > > @@ -343,16 +383,82 @@ static int ad7949_spi_probe(struct spi_device *spi) > > > > return -EINVAL; > > > > } > > > > > > > > - ad7949_adc->vref = devm_regulator_get(dev, "vref"); > > > > + /* Setup external voltage ref, buffered? */ > > > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin"); > > > > if (IS_ERR(ad7949_adc->vref)) { > > > > - dev_err(dev, "fail to request regulator\n"); > > > > - return PTR_ERR(ad7949_adc->vref); > > > > + ret = PTR_ERR(ad7949_adc->vref); > > > > + if (ret != -ENODEV) > > > > + return ret; > > > > + /* unbuffered? */ > > > > + ad7949_adc->vref = devm_regulator_get_optional(dev, "vref"); > > > > + if (IS_ERR(ad7949_adc->vref)) { > > > > + ret = PTR_ERR(ad7949_adc->vref); > > > > + if (ret != -ENODEV) > > > > + return ret; > > > > + /* Internal then */ > > > > + mode = AD7949_CFG_VAL_REF_INT_4096; > > > > + } else { > > > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP; > > > > + } > > > > + } else { > > > > + mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; > > > > } > > > > > > > > - ret = regulator_enable(ad7949_adc->vref); > > > > - if (ret < 0) { > > > > - dev_err(dev, "fail to enable regulator\n"); > > > > - return ret; > > > > + if (mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > > > + ret = regulator_enable(ad7949_adc->vref); > > > > + if (ret < 0) { > > > > + dev_err(dev, "fail to enable regulator\n"); > > > > + return ret; > > > > + } > > > > + > > > > + ret = devm_add_action_or_reset(dev, ad7949_disable_reg, > > > > + ad7949_adc->vref); > > > > + if (ret) > > > > + return ret; > > > > + } > > > > + > > > > + ad7949_adc->channels = devm_kcalloc(dev, spec->num_channels, > > > > + sizeof(*ad7949_adc->channels), > > > > + GFP_KERNEL); > > > > + if (!ad7949_adc->channels) { > > > > + dev_err(dev, "unable to allocate ADC channels\n"); > > > > + return -ENOMEM; > > > > + } > > > > + > > > > + /* Initialize all channel structures */ > > > > + for (i = 0; i < spec->num_channels; i++) > > > > + ad7949_adc->channels[i].refsel = mode; > > > > + > > > > + /* Read channel specific information form the devicetree */ > > > > + device_for_each_child_node(dev, child) { > > > > + ret = fwnode_property_read_u32(child, "reg", &i); > > > > + if (ret) { > > > > + dev_err(dev, "missing reg property in %pfw\n", child); > > > > + fwnode_handle_put(child); > > > > + return ret; > > > > + } > > > > + > > > > + ad7949_chan = &ad7949_adc->channels[i]; > > > > + > > > > + ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > > > + if (ret < 0 && ret != -EINVAL) { > > > > + dev_err(dev, "invalid internal reference in %pfw\n", child); > > > > + fwnode_handle_put(child); > > > > + return ret; > > > > + } > > > > Hi Jonathan, > > > > > > > > So if we are using external voltage, then we'd not expect this to exist. > > > ret != -EINVAL should deal with that. However, we then hit the following > > > switch > > > and temp isn't set to an appropriate value so we get the error. > > > > > > Am I missing something? > > > > You're right that using an external reference, will cause this to fail. > > My apologies, I've done a poor job of testing the last two revisions of > > this patch. I'll do better. > > > > Since a regulator is also required when we're using an external source, > > I'll add a check for that. Something like this: > > > > ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > if (ret == -EINVAL && mode & AD7949_CFG_VAL_REF_EXTERNAL) { > > continue; > > } else if (ret < 0) { > > dev_err(dev, "invalid voltage reference in %pfw\n", child); > > fwnode_handle_put(child); > > return ret; > > } > > Makes sense. Hi Jonathan, After getting access to another setup to run more tests, I noticed that setting the reference per channel isn't really feasible. It take a little while for the reference to be updated internally even though the request is sent out properly, and reading channels in a sequence returns bad values. I'll resend this without the per-channel configuration and make adi,internal-ref-microvolt a global parameter. Sorry about that, Liam > > > > > Given that we can now have a different scale for each channel based on > > the vref source, should BIT(IIO_CHAN_INFO_SCALE) be moved to > > .info_mask_separate in the channel definition? > Yes, good point. > > Hopefully no one will notice the ABI change *crosses fingers*. > > Jonathan > > > > > Thanks, > > Liam > > > > > > > > > + > > > > + switch (tmp) { > > > > + case 2500000: > > > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_2500; > > > > + break; > > > > + case 4096000: > > > > + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_4096; > > > > + break; > > > > + default: > > > > + dev_err(dev, "unsupported internal voltage reference\n"); > > > > + fwnode_handle_put(child); > > > > + return -EINVAL; > > > > + } > > > > } > > > > > > > > mutex_init(&ad7949_adc->lock); > > > > @@ -373,7 +479,6 @@ static int ad7949_spi_probe(struct spi_device *spi) > > > > > > > > err: > > > > mutex_destroy(&ad7949_adc->lock); > > > > - regulator_disable(ad7949_adc->vref); > > > > > > > > return ret; > > > > } > > > > @@ -385,7 +490,6 @@ static int ad7949_spi_remove(struct spi_device *spi) > > > > > > > > iio_device_unregister(indio_dev); > > > > mutex_destroy(&ad7949_adc->lock); > > > > - regulator_disable(ad7949_adc->vref); > > > > > > > > return 0; > > > > } > >
On Fri, Aug 13, 2021 at 11:51 PM Liam Beguin <liambeguin@gmail.com> wrote: > On Mon Aug 9, 2021 at 3:42 PM EDT, Jonathan Cameron wrote: ... > > > > > + /* Read channel specific information form the devicetree */ from > > > > > + device_for_each_child_node(dev, child) { > > > > > + ret = fwnode_property_read_u32(child, "reg", &i); > > > > > + if (ret) { > > > > > + dev_err(dev, "missing reg property in %pfw\n", child); > > > > > + fwnode_handle_put(child); > > > > > + return ret; > > > > > + } > > > > > + > > > > > + ad7949_chan = &ad7949_adc->channels[i]; > > > > > + > > > > > + ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); > > > > > + if (ret < 0 && ret != -EINVAL) { > > > > > + dev_err(dev, "invalid internal reference in %pfw\n", child); > > > > > + fwnode_handle_put(child); > > > > > + return ret; > > > > > + } > After getting access to another setup to run more tests, I noticed > that setting the reference per channel isn't really feasible. Is it a hardware limitation?
diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c index 3f94ae639a44..14a7c79d637e 100644 --- a/drivers/iio/adc/ad7949.c +++ b/drivers/iio/adc/ad7949.c @@ -35,7 +35,11 @@ /* REF: reference/buffer selection */ #define AD7949_CFG_BIT_REF GENMASK(5, 3) -#define AD7949_CFG_VAL_REF_EXT_BUF 7 +#define AD7949_CFG_VAL_REF_EXT_TEMP_BUF 3 +#define AD7949_CFG_VAL_REF_EXT_TEMP 2 +#define AD7949_CFG_VAL_REF_INT_4096 1 +#define AD7949_CFG_VAL_REF_INT_2500 0 +#define AD7949_CFG_VAL_REF_EXTERNAL BIT(1) /* SEQ: channel sequencer. Allows for scanning channels */ #define AD7949_CFG_BIT_SEQ GENMASK(2, 1) @@ -60,6 +64,14 @@ static const struct ad7949_adc_spec ad7949_adc_spec[] = { [ID_AD7689] = { .num_channels = 8, .resolution = 16 }, }; +/** + * struct ad7949_channel - ADC Channel parameters + * @refsel: reference selection + */ +struct ad7949_channel { + u32 refsel; +}; + /** * struct ad7949_adc_chip - AD ADC chip * @lock: protects write sequences @@ -78,6 +90,7 @@ struct ad7949_adc_chip { struct regulator *vref; struct iio_dev *indio_dev; struct spi_device *spi; + struct ad7949_channel *channels; u8 resolution; u8 bits_per_word; u16 cfg; @@ -136,6 +149,7 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, int ret; int i; struct spi_message msg; + struct ad7949_channel *ad7949_chan = &ad7949_adc->channels[channel]; struct spi_transfer tx[] = { { .len = 2, @@ -156,8 +170,9 @@ static int ad7949_spi_read_channel(struct ad7949_adc_chip *ad7949_adc, int *val, */ for (i = 0; i < 2; i++) { ret = ad7949_spi_write_cfg(ad7949_adc, - FIELD_PREP(AD7949_CFG_BIT_INX, channel), - AD7949_CFG_BIT_INX); + FIELD_PREP(AD7949_CFG_BIT_INX, channel) | + FIELD_PREP(AD7949_CFG_BIT_REF, ad7949_chan->refsel), + AD7949_CFG_BIT_INX | AD7949_CFG_BIT_REF); if (ret) return ret; if (channel == ad7949_adc->current_channel) @@ -225,6 +240,7 @@ static int ad7949_spi_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct ad7949_adc_chip *ad7949_adc = iio_priv(indio_dev); + struct ad7949_channel *ad7949_chan = &ad7949_adc->channels[chan->channel]; int ret; if (!val) @@ -242,12 +258,26 @@ static int ad7949_spi_read_raw(struct iio_dev *indio_dev, return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: - ret = regulator_get_voltage(ad7949_adc->vref); - if (ret < 0) - return ret; + switch (ad7949_chan->refsel) { + case AD7949_CFG_VAL_REF_INT_2500: + *val = 2500; + break; + case AD7949_CFG_VAL_REF_INT_4096: + *val = 4096; + break; + case AD7949_CFG_VAL_REF_EXT_TEMP: + case AD7949_CFG_VAL_REF_EXT_TEMP_BUF: + ret = regulator_get_voltage(ad7949_adc->vref); + if (ret < 0) + return ret; + + /* convert value back to mV */ + *val = ret / 1000; + break; + } - *val = ret / 5000; - return IIO_VAL_INT; + *val2 = (1 << ad7949_adc->resolution) - 1; + return IIO_VAL_FRACTIONAL; } return -EINVAL; @@ -286,7 +316,7 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc) FIELD_PREP(AD7949_CFG_BIT_INCC, AD7949_CFG_VAL_INCC_UNIPOLAR_GND) | FIELD_PREP(AD7949_CFG_BIT_INX, ad7949_adc->current_channel) | FIELD_PREP(AD7949_CFG_BIT_BW_FULL, 1) | - FIELD_PREP(AD7949_CFG_BIT_REF, AD7949_CFG_VAL_REF_EXT_BUF) | + FIELD_PREP(AD7949_CFG_BIT_REF, ad7949_adc->channels[0].refsel) | FIELD_PREP(AD7949_CFG_BIT_SEQ, 0x0) | FIELD_PREP(AD7949_CFG_BIT_RBN, 1); @@ -302,14 +332,24 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc) return ret; } +static void ad7949_disable_reg(void *reg) +{ + regulator_disable(reg); +} + static int ad7949_spi_probe(struct spi_device *spi) { u32 spi_ctrl_mask = spi->controller->bits_per_word_mask; struct device *dev = &spi->dev; const struct ad7949_adc_spec *spec; struct ad7949_adc_chip *ad7949_adc; + struct ad7949_channel *ad7949_chan; + struct fwnode_handle *child; struct iio_dev *indio_dev; + int mode; + u32 tmp; int ret; + int i; indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc)); if (!indio_dev) { @@ -343,16 +383,82 @@ static int ad7949_spi_probe(struct spi_device *spi) return -EINVAL; } - ad7949_adc->vref = devm_regulator_get(dev, "vref"); + /* Setup external voltage ref, buffered? */ + ad7949_adc->vref = devm_regulator_get_optional(dev, "vrefin"); if (IS_ERR(ad7949_adc->vref)) { - dev_err(dev, "fail to request regulator\n"); - return PTR_ERR(ad7949_adc->vref); + ret = PTR_ERR(ad7949_adc->vref); + if (ret != -ENODEV) + return ret; + /* unbuffered? */ + ad7949_adc->vref = devm_regulator_get_optional(dev, "vref"); + if (IS_ERR(ad7949_adc->vref)) { + ret = PTR_ERR(ad7949_adc->vref); + if (ret != -ENODEV) + return ret; + /* Internal then */ + mode = AD7949_CFG_VAL_REF_INT_4096; + } else { + mode = AD7949_CFG_VAL_REF_EXT_TEMP; + } + } else { + mode = AD7949_CFG_VAL_REF_EXT_TEMP_BUF; } - ret = regulator_enable(ad7949_adc->vref); - if (ret < 0) { - dev_err(dev, "fail to enable regulator\n"); - return ret; + if (mode & AD7949_CFG_VAL_REF_EXTERNAL) { + ret = regulator_enable(ad7949_adc->vref); + if (ret < 0) { + dev_err(dev, "fail to enable regulator\n"); + return ret; + } + + ret = devm_add_action_or_reset(dev, ad7949_disable_reg, + ad7949_adc->vref); + if (ret) + return ret; + } + + ad7949_adc->channels = devm_kcalloc(dev, spec->num_channels, + sizeof(*ad7949_adc->channels), + GFP_KERNEL); + if (!ad7949_adc->channels) { + dev_err(dev, "unable to allocate ADC channels\n"); + return -ENOMEM; + } + + /* Initialize all channel structures */ + for (i = 0; i < spec->num_channels; i++) + ad7949_adc->channels[i].refsel = mode; + + /* Read channel specific information form the devicetree */ + device_for_each_child_node(dev, child) { + ret = fwnode_property_read_u32(child, "reg", &i); + if (ret) { + dev_err(dev, "missing reg property in %pfw\n", child); + fwnode_handle_put(child); + return ret; + } + + ad7949_chan = &ad7949_adc->channels[i]; + + ret = fwnode_property_read_u32(child, "adi,internal-ref-microvolt", &tmp); + if (ret < 0 && ret != -EINVAL) { + dev_err(dev, "invalid internal reference in %pfw\n", child); + fwnode_handle_put(child); + return ret; + } + + switch (tmp) { + case 2500000: + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_2500; + break; + case 4096000: + ad7949_chan->refsel = AD7949_CFG_VAL_REF_INT_4096; + break; + default: + dev_err(dev, "unsupported internal voltage reference\n"); + fwnode_handle_put(child); + return -EINVAL; + } } mutex_init(&ad7949_adc->lock); @@ -373,7 +479,6 @@ static int ad7949_spi_probe(struct spi_device *spi) err: mutex_destroy(&ad7949_adc->lock); - regulator_disable(ad7949_adc->vref); return ret; } @@ -385,7 +490,6 @@ static int ad7949_spi_remove(struct spi_device *spi) iio_device_unregister(indio_dev); mutex_destroy(&ad7949_adc->lock); - regulator_disable(ad7949_adc->vref); return 0; }