From: Jonathan Santos Date: Wed, 11 Jun 2025 11:50:44 +0000 (-0300) Subject: iio: adc: ad7768-1: add regulator to control VCM output X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=96b6e814afd2ac475f96e52fcf38673c3631b6df;p=users%2Fhch%2Fmisc.git iio: adc: ad7768-1: add regulator to control VCM output The VCM output voltage can be used as a common-mode voltage within the amplifier preconditioning circuits external to the AD7768-1. This change allows the user to configure VCM output using the regulator framework. Acked-by: Marcelo Schmitt Reviewed-by: David Lechner Reviewed-by: Andy Shevchenko Signed-off-by: Jonathan Santos Link: https://patch.msgid.link/1f02312fdc4131168b194d59f4b1688dc68ea36e.1749569957.git.Jonathan.Santos@analog.com Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 799437f918df..7ad58ca5173f 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -354,6 +354,7 @@ config AD7766 config AD7768_1 tristate "Analog Devices AD7768-1 ADC driver" depends on SPI + select REGULATOR select REGMAP_SPI select IIO_BUFFER select IIO_TRIGGER diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index 8b414a102864..68f876e5d31c 100644 --- a/drivers/iio/adc/ad7768-1.c +++ b/drivers/iio/adc/ad7768-1.c @@ -13,9 +13,11 @@ #include #include #include +#include #include #include #include +#include #include #include @@ -82,6 +84,12 @@ #define AD7768_CONV_MODE_MSK GENMASK(2, 0) #define AD7768_CONV_MODE(x) FIELD_PREP(AD7768_CONV_MODE_MSK, x) +/* AD7768_REG_ANALOG2 */ +#define AD7768_REG_ANALOG2_VCM_MSK GENMASK(2, 0) +#define AD7768_REG_ANALOG2_VCM(x) FIELD_PREP(AD7768_REG_ANALOG2_VCM_MSK, (x)) + +#define AD7768_VCM_OFF 0x07 + enum ad7768_conv_mode { AD7768_CONTINUOUS, AD7768_ONE_SHOT, @@ -159,6 +167,8 @@ struct ad7768_state { struct regmap *regmap; struct regmap *regmap24; struct regulator *vref; + struct regulator_dev *vcm_rdev; + unsigned int vcm_output_sel; struct clk *mclk; unsigned int mclk_freq; unsigned int samp_freq; @@ -662,6 +672,150 @@ static int ad7768_triggered_buffer_alloc(struct iio_dev *indio_dev) &ad7768_buffer_ops); } +static int ad7768_vcm_enable(struct regulator_dev *rdev) +{ + struct iio_dev *indio_dev = rdev_get_drvdata(rdev); + struct ad7768_state *st = iio_priv(indio_dev); + int ret, regval; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + /* To enable, set the last selected output */ + regval = AD7768_REG_ANALOG2_VCM(st->vcm_output_sel + 1); + ret = regmap_update_bits(st->regmap, AD7768_REG_ANALOG2, + AD7768_REG_ANALOG2_VCM_MSK, regval); + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad7768_vcm_disable(struct regulator_dev *rdev) +{ + struct iio_dev *indio_dev = rdev_get_drvdata(rdev); + struct ad7768_state *st = iio_priv(indio_dev); + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_update_bits(st->regmap, AD7768_REG_ANALOG2, + AD7768_REG_ANALOG2_VCM_MSK, AD7768_VCM_OFF); + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad7768_vcm_is_enabled(struct regulator_dev *rdev) +{ + struct iio_dev *indio_dev = rdev_get_drvdata(rdev); + struct ad7768_state *st = iio_priv(indio_dev); + int ret, val; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_read(st->regmap, AD7768_REG_ANALOG2, &val); + iio_device_release_direct(indio_dev); + if (ret) + return ret; + + return FIELD_GET(AD7768_REG_ANALOG2_VCM_MSK, val) != AD7768_VCM_OFF; +} + +static int ad7768_set_voltage_sel(struct regulator_dev *rdev, + unsigned int selector) +{ + unsigned int regval = AD7768_REG_ANALOG2_VCM(selector + 1); + struct iio_dev *indio_dev = rdev_get_drvdata(rdev); + struct ad7768_state *st = iio_priv(indio_dev); + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_update_bits(st->regmap, AD7768_REG_ANALOG2, + AD7768_REG_ANALOG2_VCM_MSK, regval); + iio_device_release_direct(indio_dev); + if (ret) + return ret; + + st->vcm_output_sel = selector; + + return 0; +} + +static int ad7768_get_voltage_sel(struct regulator_dev *rdev) +{ + struct iio_dev *indio_dev = rdev_get_drvdata(rdev); + struct ad7768_state *st = iio_priv(indio_dev); + int ret, val; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_read(st->regmap, AD7768_REG_ANALOG2, &val); + iio_device_release_direct(indio_dev); + if (ret) + return ret; + + val = FIELD_GET(AD7768_REG_ANALOG2_VCM_MSK, val); + + return clamp(val, 1, rdev->desc->n_voltages) - 1; +} + +static const struct regulator_ops vcm_regulator_ops = { + .enable = ad7768_vcm_enable, + .disable = ad7768_vcm_disable, + .is_enabled = ad7768_vcm_is_enabled, + .list_voltage = regulator_list_voltage_table, + .set_voltage_sel = ad7768_set_voltage_sel, + .get_voltage_sel = ad7768_get_voltage_sel, +}; + +static const unsigned int vcm_voltage_table[] = { + 2500000, + 2050000, + 1650000, + 1900000, + 1100000, + 900000, +}; + +static const struct regulator_desc vcm_desc = { + .name = "ad7768-1-vcm", + .of_match = "vcm-output", + .regulators_node = "regulators", + .n_voltages = ARRAY_SIZE(vcm_voltage_table), + .volt_table = vcm_voltage_table, + .ops = &vcm_regulator_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, +}; + +static int ad7768_register_regulators(struct device *dev, struct ad7768_state *st, + struct iio_dev *indio_dev) +{ + struct regulator_config config = { + .dev = dev, + .driver_data = indio_dev, + }; + int ret; + + /* Disable the regulator before registering it */ + ret = regmap_update_bits(st->regmap, AD7768_REG_ANALOG2, + AD7768_REG_ANALOG2_VCM_MSK, AD7768_VCM_OFF); + if (ret) + return ret; + + st->vcm_rdev = devm_regulator_register(dev, &vcm_desc, &config); + if (IS_ERR(st->vcm_rdev)) + return dev_err_probe(dev, PTR_ERR(st->vcm_rdev), + "failed to register VCM regulator\n"); + + return 0; +} + static int ad7768_probe(struct spi_device *spi) { struct ad7768_state *st; @@ -726,6 +880,11 @@ static int ad7768_probe(struct spi_device *spi) indio_dev->info = &ad7768_info; indio_dev->modes = INDIO_DIRECT_MODE; + /* Register VCM output regulator */ + ret = ad7768_register_regulators(&spi->dev, st, indio_dev); + if (ret) + return ret; + ret = ad7768_setup(st); if (ret < 0) { dev_err(&spi->dev, "AD7768 setup failed\n");