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1// SPDX-License-Identifier: GPL-2.0+2/*3 * ADC driver for the RICOH RN5T618 power management chip family4 *5 * Copyright (C) 2019 Andreas Kemnade6 */7 8#include <linux/kernel.h>9#include <linux/device.h>10#include <linux/errno.h>11#include <linux/interrupt.h>12#include <linux/init.h>13#include <linux/module.h>14#include <linux/mfd/rn5t618.h>15#include <linux/platform_device.h>16#include <linux/completion.h>17#include <linux/regmap.h>18#include <linux/iio/iio.h>19#include <linux/iio/driver.h>20#include <linux/iio/machine.h>21#include <linux/slab.h>22 23#define RN5T618_ADC_CONVERSION_TIMEOUT (msecs_to_jiffies(500))24#define RN5T618_REFERENCE_VOLT 250025 26/* mask for selecting channels for single conversion */27#define RN5T618_ADCCNT3_CHANNEL_MASK 0x728/* average 4-time conversion mode */29#define RN5T618_ADCCNT3_AVG BIT(3)30/* set for starting a single conversion, gets cleared by hw when done */31#define RN5T618_ADCCNT3_GODONE BIT(4)32/* automatic conversion, period is in ADCCNT2, selected channels are33 * in ADCCNT134 */35#define RN5T618_ADCCNT3_AUTO BIT(5)36#define RN5T618_ADCEND_IRQ BIT(0)37 38struct rn5t618_adc_data {39 struct device *dev;40 struct rn5t618 *rn5t618;41 struct completion conv_completion;42 int irq;43};44 45enum rn5t618_channels {46 LIMMON = 0,47 VBAT,48 VADP,49 VUSB,50 VSYS,51 VTHM,52 AIN1,53 AIN054};55 56static const struct u16_fract rn5t618_ratios[8] = {57 [LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */58 [VBAT] = {2, 1},59 [VADP] = {3, 1},60 [VUSB] = {3, 1},61 [VSYS] = {3, 1},62 [VTHM] = {1, 1},63 [AIN1] = {1, 1},64 [AIN0] = {1, 1},65};66 67static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val)68{69 u8 data[2];70 int ret;71 72 ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data));73 if (ret < 0)74 return ret;75 76 *val = (data[0] << 4) | (data[1] & 0xF);77 78 return 0;79}80 81static irqreturn_t rn5t618_adc_irq(int irq, void *data)82{83 struct rn5t618_adc_data *adc = data;84 unsigned int r = 0;85 int ret;86 87 /* clear low & high threshold irqs */88 regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0);89 regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0);90 91 ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r);92 if (ret < 0)93 dev_err(adc->dev, "failed to read IRQ status: %d\n", ret);94 95 regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0);96 97 if (r & RN5T618_ADCEND_IRQ)98 complete(&adc->conv_completion);99 100 return IRQ_HANDLED;101}102 103static int rn5t618_adc_read(struct iio_dev *iio_dev,104 const struct iio_chan_spec *chan,105 int *val, int *val2, long mask)106{107 struct rn5t618_adc_data *adc = iio_priv(iio_dev);108 u16 raw;109 int ret;110 111 if (mask == IIO_CHAN_INFO_SCALE) {112 *val = RN5T618_REFERENCE_VOLT *113 rn5t618_ratios[chan->channel].numerator;114 *val2 = rn5t618_ratios[chan->channel].denominator * 4095;115 116 return IIO_VAL_FRACTIONAL;117 }118 119 /* select channel */120 ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,121 RN5T618_ADCCNT3_CHANNEL_MASK,122 chan->channel);123 if (ret < 0)124 return ret;125 126 ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3,127 RN5T618_ADCEND_IRQ);128 if (ret < 0)129 return ret;130 131 ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,132 RN5T618_ADCCNT3_AVG,133 mask == IIO_CHAN_INFO_AVERAGE_RAW ?134 RN5T618_ADCCNT3_AVG : 0);135 if (ret < 0)136 return ret;137 138 init_completion(&adc->conv_completion);139 /* single conversion */140 ret = regmap_set_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,141 RN5T618_ADCCNT3_GODONE);142 if (ret < 0)143 return ret;144 145 ret = wait_for_completion_timeout(&adc->conv_completion,146 RN5T618_ADC_CONVERSION_TIMEOUT);147 if (ret == 0) {148 dev_warn(adc->dev, "timeout waiting for adc result\n");149 return -ETIMEDOUT;150 }151 152 ret = rn5t618_read_adc_reg(adc->rn5t618,153 RN5T618_ILIMDATAH + 2 * chan->channel,154 &raw);155 if (ret < 0)156 return ret;157 158 *val = raw;159 160 return IIO_VAL_INT;161}162 163static const struct iio_info rn5t618_adc_iio_info = {164 .read_raw = &rn5t618_adc_read,165};166 167#define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \168 .type = _type, \169 .channel = _channel, \170 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \171 BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \172 BIT(IIO_CHAN_INFO_SCALE), \173 .datasheet_name = _name, \174 .indexed = 1. \175}176 177static const struct iio_chan_spec rn5t618_adc_iio_channels[] = {178 RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"),179 RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"),180 RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"),181 RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"),182 RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"),183 RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"),184 RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"),185 RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0")186};187 188static struct iio_map rn5t618_maps[] = {189 IIO_MAP("VADP", "rn5t618-power", "vadp"),190 IIO_MAP("VUSB", "rn5t618-power", "vusb"),191 { /* sentinel */ }192};193 194static int rn5t618_adc_probe(struct platform_device *pdev)195{196 int ret;197 struct iio_dev *iio_dev;198 struct rn5t618_adc_data *adc;199 struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);200 201 iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));202 if (!iio_dev) {203 dev_err(&pdev->dev, "failed allocating iio device\n");204 return -ENOMEM;205 }206 207 adc = iio_priv(iio_dev);208 adc->dev = &pdev->dev;209 adc->rn5t618 = rn5t618;210 211 if (rn5t618->irq_data)212 adc->irq = regmap_irq_get_virq(rn5t618->irq_data,213 RN5T618_IRQ_ADC);214 215 if (adc->irq <= 0) {216 dev_err(&pdev->dev, "get virq failed\n");217 return -EINVAL;218 }219 220 init_completion(&adc->conv_completion);221 222 iio_dev->name = dev_name(&pdev->dev);223 iio_dev->info = &rn5t618_adc_iio_info;224 iio_dev->modes = INDIO_DIRECT_MODE;225 iio_dev->channels = rn5t618_adc_iio_channels;226 iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels);227 228 /* stop any auto-conversion */229 ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0);230 if (ret < 0)231 return ret;232 233 platform_set_drvdata(pdev, iio_dev);234 235 ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL,236 rn5t618_adc_irq,237 IRQF_ONESHOT, dev_name(adc->dev),238 adc);239 if (ret < 0) {240 dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret);241 return ret;242 }243 244 ret = devm_iio_map_array_register(adc->dev, iio_dev, rn5t618_maps);245 if (ret < 0)246 return ret;247 248 return devm_iio_device_register(adc->dev, iio_dev);249}250 251static struct platform_driver rn5t618_adc_driver = {252 .driver = {253 .name = "rn5t618-adc",254 },255 .probe = rn5t618_adc_probe,256};257 258module_platform_driver(rn5t618_adc_driver);259MODULE_ALIAS("platform:rn5t618-adc");260MODULE_DESCRIPTION("RICOH RN5T618 ADC driver");261MODULE_LICENSE("GPL");262