1 // SPDX-License-Identifier: GPL-2.0+
3 * ADC driver for the RICOH RN5T618 power management chip family
5 * Copyright (C) 2019 Andreas Kemnade
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/slab.h>
21 #define RN5T618_ADC_CONVERSION_TIMEOUT (msecs_to_jiffies(500))
22 #define RN5T618_REFERENCE_VOLT 2500
24 /* mask for selecting channels for single conversion */
25 #define RN5T618_ADCCNT3_CHANNEL_MASK 0x7
26 /* average 4-time conversion mode */
27 #define RN5T618_ADCCNT3_AVG BIT(3)
28 /* set for starting a single conversion, gets cleared by hw when done */
29 #define RN5T618_ADCCNT3_GODONE BIT(4)
30 /* automatic conversion, period is in ADCCNT2, selected channels are
33 #define RN5T618_ADCCNT3_AUTO BIT(5)
34 #define RN5T618_ADCEND_IRQ BIT(0)
36 struct rn5t618_adc_data {
38 struct rn5t618 *rn5t618;
39 struct completion conv_completion;
43 struct rn5t618_channel_ratios {
48 enum rn5t618_channels {
59 static const struct rn5t618_channel_ratios rn5t618_ratios[8] = {
60 [LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */
70 static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val)
75 ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data));
79 *val = (data[0] << 4) | (data[1] & 0xF);
84 static irqreturn_t rn5t618_adc_irq(int irq, void *data)
86 struct rn5t618_adc_data *adc = data;
90 /* clear low & high threshold irqs */
91 regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0);
92 regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0);
94 ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r);
96 dev_err(adc->dev, "failed to read IRQ status: %d\n", ret);
98 regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0);
100 if (r & RN5T618_ADCEND_IRQ)
101 complete(&adc->conv_completion);
106 static int rn5t618_adc_read(struct iio_dev *iio_dev,
107 const struct iio_chan_spec *chan,
108 int *val, int *val2, long mask)
110 struct rn5t618_adc_data *adc = iio_priv(iio_dev);
114 if (mask == IIO_CHAN_INFO_SCALE) {
115 *val = RN5T618_REFERENCE_VOLT *
116 rn5t618_ratios[chan->channel].numerator;
117 *val2 = rn5t618_ratios[chan->channel].denominator * 4095;
119 return IIO_VAL_FRACTIONAL;
123 ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
124 RN5T618_ADCCNT3_CHANNEL_MASK,
129 ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3,
134 ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
136 mask == IIO_CHAN_INFO_AVERAGE_RAW ?
137 RN5T618_ADCCNT3_AVG : 0);
141 init_completion(&adc->conv_completion);
142 /* single conversion */
143 ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
144 RN5T618_ADCCNT3_GODONE,
145 RN5T618_ADCCNT3_GODONE);
149 ret = wait_for_completion_timeout(&adc->conv_completion,
150 RN5T618_ADC_CONVERSION_TIMEOUT);
152 dev_warn(adc->dev, "timeout waiting for adc result\n");
156 ret = rn5t618_read_adc_reg(adc->rn5t618,
157 RN5T618_ILIMDATAH + 2 * chan->channel,
167 static const struct iio_info rn5t618_adc_iio_info = {
168 .read_raw = &rn5t618_adc_read,
171 #define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \
173 .channel = _channel, \
174 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
175 BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
176 BIT(IIO_CHAN_INFO_SCALE), \
177 .datasheet_name = _name, \
181 static const struct iio_chan_spec rn5t618_adc_iio_channels[] = {
182 RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"),
183 RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"),
184 RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"),
185 RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"),
186 RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"),
187 RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"),
188 RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"),
189 RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0")
192 static int rn5t618_adc_probe(struct platform_device *pdev)
195 struct iio_dev *iio_dev;
196 struct rn5t618_adc_data *adc;
197 struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
199 iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
201 dev_err(&pdev->dev, "failed allocating iio device\n");
205 adc = iio_priv(iio_dev);
206 adc->dev = &pdev->dev;
207 adc->rn5t618 = rn5t618;
209 if (rn5t618->irq_data)
210 adc->irq = regmap_irq_get_virq(rn5t618->irq_data,
214 dev_err(&pdev->dev, "get virq failed\n");
218 init_completion(&adc->conv_completion);
220 iio_dev->name = dev_name(&pdev->dev);
221 iio_dev->info = &rn5t618_adc_iio_info;
222 iio_dev->modes = INDIO_DIRECT_MODE;
223 iio_dev->channels = rn5t618_adc_iio_channels;
224 iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels);
226 /* stop any auto-conversion */
227 ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0);
231 platform_set_drvdata(pdev, iio_dev);
233 ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL,
235 IRQF_ONESHOT, dev_name(adc->dev),
238 dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret);
242 return devm_iio_device_register(adc->dev, iio_dev);
245 static struct platform_driver rn5t618_adc_driver = {
247 .name = "rn5t618-adc",
249 .probe = rn5t618_adc_probe,
252 module_platform_driver(rn5t618_adc_driver);
253 MODULE_ALIAS("platform:rn5t618-adc");
254 MODULE_DESCRIPTION("RICOH RN5T618 ADC driver");
255 MODULE_LICENSE("GPL");