diff options
Diffstat (limited to 'drivers/iio/adc/ad7949.c')
| -rw-r--r-- | drivers/iio/adc/ad7949.c | 92 |
1 files changed, 76 insertions, 16 deletions
diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c index a263d0fcec75..879bdca35e04 100644 --- a/drivers/iio/adc/ad7949.c +++ b/drivers/iio/adc/ad7949.c @@ -35,7 +35,11 @@ /* REF: reference/buffer selection */ #define AD7949_CFG_MASK_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_MASK_SEQ GENMASK(2, 1) @@ -66,6 +70,7 @@ static const struct ad7949_adc_spec ad7949_adc_spec[] = { * @vref: regulator generating Vref * @indio_dev: reference to iio structure * @spi: reference to spi structure + * @refsel: reference selection * @resolution: resolution of the chip * @cfg: copy of the configuration register * @current_channel: current channel in use @@ -77,6 +82,7 @@ struct ad7949_adc_chip { struct regulator *vref; struct iio_dev *indio_dev; struct spi_device *spi; + u32 refsel; u8 resolution; u16 cfg; unsigned int current_channel; @@ -221,12 +227,26 @@ 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_adc->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; @@ -265,7 +285,7 @@ static int ad7949_spi_init(struct ad7949_adc_chip *ad7949_adc) FIELD_PREP(AD7949_CFG_MASK_INCC, AD7949_CFG_VAL_INCC_UNIPOLAR_GND) | FIELD_PREP(AD7949_CFG_MASK_INX, ad7949_adc->current_channel) | FIELD_PREP(AD7949_CFG_MASK_BW_FULL, 1) | - FIELD_PREP(AD7949_CFG_MASK_REF, AD7949_CFG_VAL_REF_EXT_BUF) | + FIELD_PREP(AD7949_CFG_MASK_REF, ad7949_adc->refsel) | FIELD_PREP(AD7949_CFG_MASK_SEQ, 0x0) | FIELD_PREP(AD7949_CFG_MASK_RBN, 1); @@ -281,6 +301,11 @@ 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; @@ -288,6 +313,7 @@ static int ad7949_spi_probe(struct spi_device *spi) const struct ad7949_adc_spec *spec; struct ad7949_adc_chip *ad7949_adc; struct iio_dev *indio_dev; + u32 tmp; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*ad7949_adc)); @@ -322,16 +348,52 @@ static int ad7949_spi_probe(struct spi_device *spi) return -EINVAL; } - ad7949_adc->vref = devm_regulator_get(dev, "vref"); + /* Setup internal voltage reference */ + tmp = 4096000; + device_property_read_u32(dev, "adi,internal-ref-microvolt", &tmp); + + switch (tmp) { + case 2500000: + ad7949_adc->refsel = AD7949_CFG_VAL_REF_INT_2500; + break; + case 4096000: + ad7949_adc->refsel = AD7949_CFG_VAL_REF_INT_4096; + break; + default: + dev_err(dev, "unsupported internal voltage reference\n"); + return -EINVAL; + } + + /* Setup external voltage reference, 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; + } else { + ad7949_adc->refsel = AD7949_CFG_VAL_REF_EXT_TEMP; + } + } else { + ad7949_adc->refsel = 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 (ad7949_adc->refsel & 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; } mutex_init(&ad7949_adc->lock); @@ -352,7 +414,6 @@ static int ad7949_spi_probe(struct spi_device *spi) err: mutex_destroy(&ad7949_adc->lock); - regulator_disable(ad7949_adc->vref); return ret; } @@ -364,7 +425,6 @@ 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; } |