diff options
Diffstat (limited to 'drivers/iio/adc/rn5t618-adc.c')
| -rw-r--r-- | drivers/iio/adc/rn5t618-adc.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/iio/adc/rn5t618-adc.c b/drivers/iio/adc/rn5t618-adc.c new file mode 100644 index 000000000000..f21027e4e26a --- /dev/null +++ b/drivers/iio/adc/rn5t618-adc.c @@ -0,0 +1,256 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ADC driver for the RICOH RN5T618 power management chip family + * + * Copyright (C) 2019 Andreas Kemnade + */ + +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mfd/rn5t618.h> +#include <linux/platform_device.h> +#include <linux/completion.h> +#include <linux/regmap.h> +#include <linux/iio/iio.h> +#include <linux/slab.h> + +#define RN5T618_ADC_CONVERSION_TIMEOUT (msecs_to_jiffies(500)) +#define RN5T618_REFERENCE_VOLT 2500 + +/* mask for selecting channels for single conversion */ +#define RN5T618_ADCCNT3_CHANNEL_MASK 0x7 +/* average 4-time conversion mode */ +#define RN5T618_ADCCNT3_AVG BIT(3) +/* set for starting a single conversion, gets cleared by hw when done */ +#define RN5T618_ADCCNT3_GODONE BIT(4) +/* automatic conversion, period is in ADCCNT2, selected channels are + * in ADCCNT1 + */ +#define RN5T618_ADCCNT3_AUTO BIT(5) +#define RN5T618_ADCEND_IRQ BIT(0) + +struct rn5t618_adc_data { + struct device *dev; + struct rn5t618 *rn5t618; + struct completion conv_completion; + int irq; +}; + +struct rn5t618_channel_ratios { + u16 numerator; + u16 denominator; +}; + +enum rn5t618_channels { + LIMMON = 0, + VBAT, + VADP, + VUSB, + VSYS, + VTHM, + AIN1, + AIN0 +}; + +static const struct rn5t618_channel_ratios rn5t618_ratios[8] = { + [LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */ + [VBAT] = {2, 1}, + [VADP] = {3, 1}, + [VUSB] = {3, 1}, + [VSYS] = {3, 1}, + [VTHM] = {1, 1}, + [AIN1] = {1, 1}, + [AIN0] = {1, 1}, +}; + +static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val) +{ + u8 data[2]; + int ret; + + ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data)); + if (ret < 0) + return ret; + + *val = (data[0] << 4) | (data[1] & 0xF); + + return 0; +} + +static irqreturn_t rn5t618_adc_irq(int irq, void *data) +{ + struct rn5t618_adc_data *adc = data; + unsigned int r = 0; + int ret; + + /* clear low & high threshold irqs */ + regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0); + regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0); + + ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r); + if (ret < 0) + dev_err(adc->dev, "failed to read IRQ status: %d\n", ret); + + regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0); + + if (r & RN5T618_ADCEND_IRQ) + complete(&adc->conv_completion); + + return IRQ_HANDLED; +} + +static int rn5t618_adc_read(struct iio_dev *iio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long mask) +{ + struct rn5t618_adc_data *adc = iio_priv(iio_dev); + u16 raw; + int ret; + + if (mask == IIO_CHAN_INFO_SCALE) { + *val = RN5T618_REFERENCE_VOLT * + rn5t618_ratios[chan->channel].numerator; + *val2 = rn5t618_ratios[chan->channel].denominator * 4095; + + return IIO_VAL_FRACTIONAL; + } + + /* select channel */ + ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, + RN5T618_ADCCNT3_CHANNEL_MASK, + chan->channel); + if (ret < 0) + return ret; + + ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3, + RN5T618_ADCEND_IRQ); + if (ret < 0) + return ret; + + ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, + RN5T618_ADCCNT3_AVG, + mask == IIO_CHAN_INFO_AVERAGE_RAW ? + RN5T618_ADCCNT3_AVG : 0); + if (ret < 0) + return ret; + + init_completion(&adc->conv_completion); + /* single conversion */ + ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, + RN5T618_ADCCNT3_GODONE, + RN5T618_ADCCNT3_GODONE); + if (ret < 0) + return ret; + + ret = wait_for_completion_timeout(&adc->conv_completion, + RN5T618_ADC_CONVERSION_TIMEOUT); + if (ret == 0) { + dev_warn(adc->dev, "timeout waiting for adc result\n"); + return -ETIMEDOUT; + } + + ret = rn5t618_read_adc_reg(adc->rn5t618, + RN5T618_ILIMDATAH + 2 * chan->channel, + &raw); + if (ret < 0) + return ret; + + *val = raw; + + return IIO_VAL_INT; +} + +static const struct iio_info rn5t618_adc_iio_info = { + .read_raw = &rn5t618_adc_read, +}; + +#define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \ + .type = _type, \ + .channel = _channel, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .datasheet_name = _name, \ + .indexed = 1. \ +} + +static const struct iio_chan_spec rn5t618_adc_iio_channels[] = { + RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"), + RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"), + RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"), + RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"), + RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"), + RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"), + RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"), + RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0") +}; + +static int rn5t618_adc_probe(struct platform_device *pdev) +{ + int ret; + struct iio_dev *iio_dev; + struct rn5t618_adc_data *adc; + struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent); + + iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); + if (!iio_dev) { + dev_err(&pdev->dev, "failed allocating iio device\n"); + return -ENOMEM; + } + + adc = iio_priv(iio_dev); + adc->dev = &pdev->dev; + adc->rn5t618 = rn5t618; + + if (rn5t618->irq_data) + adc->irq = regmap_irq_get_virq(rn5t618->irq_data, + RN5T618_IRQ_ADC); + + if (adc->irq <= 0) { + dev_err(&pdev->dev, "get virq failed\n"); + return -EINVAL; + } + + init_completion(&adc->conv_completion); + + iio_dev->name = dev_name(&pdev->dev); + iio_dev->dev.parent = &pdev->dev; + iio_dev->info = &rn5t618_adc_iio_info; + iio_dev->modes = INDIO_DIRECT_MODE; + iio_dev->channels = rn5t618_adc_iio_channels; + iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels); + + /* stop any auto-conversion */ + ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0); + if (ret < 0) + return ret; + + platform_set_drvdata(pdev, iio_dev); + + ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL, + rn5t618_adc_irq, + IRQF_ONESHOT, dev_name(adc->dev), + adc); + if (ret < 0) { + dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret); + return ret; + } + + return devm_iio_device_register(adc->dev, iio_dev); +} + +static struct platform_driver rn5t618_adc_driver = { + .driver = { + .name = "rn5t618-adc", + }, + .probe = rn5t618_adc_probe, +}; + +module_platform_driver(rn5t618_adc_driver); +MODULE_ALIAS("platform:rn5t618-adc"); +MODULE_DESCRIPTION("RICOH RN5T618 ADC driver"); +MODULE_LICENSE("GPL"); |