Register the SD modulator as an IIO backend device instead of a standard IIO device. Expose scale and offset information to IIO backend consumer. Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxxxxxxx> --- drivers/iio/adc/sd_adc_modulator.c | 106 +++++++++++++++++++++++------ 1 file changed, 86 insertions(+), 20 deletions(-) diff --git a/drivers/iio/adc/sd_adc_modulator.c b/drivers/iio/adc/sd_adc_modulator.c index 327cc2097f6c..e77e7884c403 100644 --- a/drivers/iio/adc/sd_adc_modulator.c +++ b/drivers/iio/adc/sd_adc_modulator.c @@ -6,44 +6,110 @@ * Author: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>. */ +#include <linux/iio/backend.h> #include <linux/iio/iio.h> #include <linux/iio/triggered_buffer.h> #include <linux/module.h> #include <linux/mod_devicetable.h> #include <linux/platform_device.h> +#include <linux/regulator/consumer.h> -static const struct iio_info iio_sd_mod_iio_info; +struct iio_sd_mod_priv { + struct regulator *vref; + int vref_mv; +}; -static const struct iio_chan_spec iio_sd_mod_ch = { - .type = IIO_VOLTAGE, - .indexed = 1, - .scan_type = { - .sign = 'u', - .realbits = 1, - .shift = 0, - }, +static int sd_mod_enable(struct iio_backend *backend) +{ + struct iio_sd_mod_priv *priv = backend->priv; + int ret; + + ret = regulator_enable(priv->vref); + if (ret) { + dev_err(&backend->dev, "Failed to enable regulator: %d\n", ret); + return ret; + } + + ret = regulator_get_voltage(priv->vref); + priv->vref_mv = ret / 1000; + + return 0; +}; + +static int sd_mod_disable(struct iio_backend *backend) +{ + struct iio_sd_mod_priv *priv = backend->priv; + + return regulator_disable(priv->vref); +}; + +static int sd_mod_read(struct iio_backend *backend, int *val, int *val2, long mask) +{ + struct iio_sd_mod_priv *priv = backend->priv; + + switch (mask) { + case IIO_CHAN_INFO_SCALE: + *val = priv->vref_mv; + *val2 = 0; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_OFFSET: + *val = 0; + *val2 = 0; + return IIO_VAL_INT; + } + + return -EINVAL; +}; + +static const struct iio_backend_ops sd_mod_ops = { + .enable = sd_mod_enable, + .disable = sd_mod_disable, + .read_raw = sd_mod_read, }; static int iio_sd_mod_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; - struct iio_dev *iio; + struct regulator *vref; + struct iio_backend *backend; + struct iio_sd_mod_priv *priv; + int ret; - iio = devm_iio_device_alloc(dev, 0); - if (!iio) + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) return -ENOMEM; - iio->name = dev_name(dev); - iio->info = &iio_sd_mod_iio_info; - iio->modes = INDIO_BUFFER_HARDWARE; + vref = devm_regulator_get_optional(dev, "vref"); + if (IS_ERR(vref)) { + if (PTR_ERR(vref) != -ENODEV) + return dev_err_probe(dev, PTR_ERR(vref), "Failed to get vref\n"); + } else { + priv->vref = vref; + } - iio->num_channels = 1; - iio->channels = &iio_sd_mod_ch; + backend = iio_backend_alloc(dev); + if (!backend) { + dev_err(dev, "Failed to allocate sd modulator backend data\n"); + return -ENOMEM; + } + + backend->priv = priv; + backend->ops = &sd_mod_ops; + + ret = iio_backend_register(backend); + if (ret) { + dev_err(dev, "Failed to register backend: %d\n", ret); + goto err_free_backend; + } - platform_set_drvdata(pdev, iio); + return 0; - return devm_iio_device_register(&pdev->dev, iio); -} +err_free_backend: + iio_backend_free(&backend->dev); + + return ret; +}; static const struct of_device_id sd_adc_of_match[] = { { .compatible = "sd-modulator" }, -- 2.25.1