diff options
Diffstat (limited to 'drivers/iio/adc/apalis-tk1-k20_adc.c')
| -rw-r--r-- | drivers/iio/adc/apalis-tk1-k20_adc.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/iio/adc/apalis-tk1-k20_adc.c b/drivers/iio/adc/apalis-tk1-k20_adc.c new file mode 100644 index 000000000000..b08f09141cdc --- /dev/null +++ b/drivers/iio/adc/apalis-tk1-k20_adc.c @@ -0,0 +1,200 @@ +/* + * Copyright 2016 Toradex AG + * Dominik Sliwa <dominik.sliwa@toradex.com> + * + * This program is free software; you can redistribute it and/or modify it under + * the terms of the GNU General Public License version 2 as published by the + * Free Software Foundation. + */ + +#include <linux/mfd/apalis-tk1-k20.h> +#include <linux/delay.h> +#include <linux/iio/iio.h> +#include <linux/iio/driver.h> +#include <linux/iio/machine.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +struct apalis_tk1_k20_adc { + struct iio_dev chip; + struct apalis_tk1_k20_regmap *apalis_tk1_k20; +}; + +static int apalis_tk1_k20_get_adc_result(struct apalis_tk1_k20_adc *adc, int id, + int *val) +{ + uint8_t adc_read[2]; + int adc_register; + + switch (id) { + case APALIS_TK1_K20_ADC1: + adc_register = APALIS_TK1_K20_ADC_CH0L; + break; + case APALIS_TK1_K20_ADC2: + adc_register = APALIS_TK1_K20_ADC_CH1L; + break; + case APALIS_TK1_K20_ADC3: + adc_register = APALIS_TK1_K20_ADC_CH2L; + break; + case APALIS_TK1_K20_ADC4: + adc_register = APALIS_TK1_K20_ADC_CH3L; + break; + default: + return -ENODEV; + } + + apalis_tk1_k20_lock(adc->apalis_tk1_k20); + + if (apalis_tk1_k20_reg_read_bulk(adc->apalis_tk1_k20, adc_register, + adc_read, 2) < 0) { + apalis_tk1_k20_unlock(adc->apalis_tk1_k20); + return -EIO; + } + *val = (adc_read[1] << 8) + adc_read[0]; + + apalis_tk1_k20_unlock(adc->apalis_tk1_k20); + + return 0; +} + +static int apalis_tk1_k20_adc_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct apalis_tk1_k20_adc *adc = iio_priv(indio_dev); + enum apalis_tk1_k20_adc_id id = chan->channel; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = apalis_tk1_k20_get_adc_result(adc, id, val) ? + -EIO : IIO_VAL_INT; + break; + case IIO_CHAN_INFO_SCALE: + *val = APALIS_TK1_K20_VADC_MILI; + *val2 = APALIS_TK1_K20_ADC_BITS; + ret = IIO_VAL_FRACTIONAL_LOG2; + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static const struct iio_info apalis_tk1_k20_adc_info = { + .read_raw = &apalis_tk1_k20_adc_read_raw, + .driver_module = THIS_MODULE, +}; + +#define APALIS_TK1_K20_CHAN(_id, _type) { \ + .type = _type, \ + .indexed = 1, \ + .channel = APALIS_TK1_K20_##_id, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .datasheet_name = #_id, \ +} + +static const struct iio_chan_spec apalis_tk1_k20_adc_channels[] = { + [APALIS_TK1_K20_ADC1] = APALIS_TK1_K20_CHAN(ADC1, IIO_VOLTAGE), + [APALIS_TK1_K20_ADC2] = APALIS_TK1_K20_CHAN(ADC2, IIO_VOLTAGE), + [APALIS_TK1_K20_ADC3] = APALIS_TK1_K20_CHAN(ADC3, IIO_VOLTAGE), + [APALIS_TK1_K20_ADC4] = APALIS_TK1_K20_CHAN(ADC4, IIO_VOLTAGE), +}; + + +static int __init apalis_tk1_k20_adc_probe(struct platform_device *pdev) +{ + struct apalis_tk1_k20_adc *priv; + struct apalis_tk1_k20_regmap *apalis_tk1_k20; + struct iio_dev *indio_dev; + int ret; + + indio_dev = iio_device_alloc(sizeof(*priv)); + if (!indio_dev) + return -ENOMEM; + + apalis_tk1_k20 = dev_get_drvdata(pdev->dev.parent); + if (!apalis_tk1_k20) { + ret = -ENODEV; + goto err_iio_device; + } + + priv = iio_priv(indio_dev); + priv->apalis_tk1_k20 = apalis_tk1_k20; + + apalis_tk1_k20_lock(apalis_tk1_k20); + + /* Enable ADC */ + apalis_tk1_k20_reg_write(apalis_tk1_k20, APALIS_TK1_K20_ADCREG, 0x01); + + apalis_tk1_k20_unlock(apalis_tk1_k20); + + platform_set_drvdata(pdev, indio_dev); + + indio_dev->dev.of_node = pdev->dev.of_node; + indio_dev->dev.parent = &pdev->dev; + indio_dev->name = pdev->name; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &apalis_tk1_k20_adc_info; + indio_dev->channels = apalis_tk1_k20_adc_channels; + indio_dev->num_channels = ARRAY_SIZE(apalis_tk1_k20_adc_channels); + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&pdev->dev, "iio dev register err: %d\n", ret); + goto err_iio_device; + } + + return 0; + +err_iio_device: + iio_device_free(indio_dev); + return ret; +} + +static int __exit apalis_tk1_k20_adc_remove(struct platform_device *pdev) +{ + struct iio_dev *indio_dev = platform_get_drvdata(pdev); + struct apalis_tk1_k20_regmap *apalis_tk1_k20 = dev_get_drvdata( + pdev->dev.parent); + + apalis_tk1_k20_lock(apalis_tk1_k20); + + /* Disable ADC */ + apalis_tk1_k20_reg_write(apalis_tk1_k20, APALIS_TK1_K20_ADCREG, 0x00); + + apalis_tk1_k20_unlock(apalis_tk1_k20); + + iio_device_unregister(indio_dev); + iio_device_free(indio_dev); + + return 0; +} + +static const struct platform_device_id apalis_tk1_k20_adc_idtable[] = { + { + .name = "apalis-tk1-k20-adc", + }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, apalis_tk1_k20_adc_idtable); + +static struct platform_driver apalis_tk1_k20_adc_driver = { + .id_table = apalis_tk1_k20_adc_idtable, + .remove = __exit_p(apalis_tk1_k20_adc_remove), + .driver = { + .name = "apalis-tk1-k20-adc", + .owner = THIS_MODULE, + }, +}; +module_platform_driver_probe(apalis_tk1_k20_adc_driver, + &apalis_tk1_k20_adc_probe); + +MODULE_DESCRIPTION("K20 ADCs on Apalis TK1"); +MODULE_AUTHOR("Dominik Sliwa"); +MODULE_LICENSE("GPL"); |