iio/adc/rn5t618-adc.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * ADC driver for the RICOH RN5T618 power management chip family
0004  *
0005  * Copyright (C) 2019 Andreas Kemnade
0006  */
0007
0008 #include <linux/kernel.h>
0009 #include <linux/device.h>
0010 #include <linux/errno.h>
0011 #include <linux/interrupt.h>
0012 #include <linux/init.h>
0013 #include <linux/module.h>
0014 #include <linux/mfd/rn5t618.h>
0015 #include <linux/platform_device.h>
0016 #include <linux/completion.h>
0017 #include <linux/regmap.h>
0018 #include <linux/iio/iio.h>
0019 #include <linux/iio/driver.h>
0020 #include <linux/iio/machine.h>
0021 #include <linux/slab.h>
0022
0023 #define RN5T618_ADC_CONVERSION_TIMEOUT   (msecs_to_jiffies(500))
0024 #define RN5T618_REFERENCE_VOLT 2500
0025
0026 /* mask for selecting channels for single conversion */
0027 #define RN5T618_ADCCNT3_CHANNEL_MASK 0x7
0028 /* average 4-time conversion mode */
0029 #define RN5T618_ADCCNT3_AVG BIT(3)
0030 /* set for starting a single conversion, gets cleared by hw when done */
0031 #define RN5T618_ADCCNT3_GODONE BIT(4)
0032 /* automatic conversion, period is in ADCCNT2, selected channels are
0033  * in ADCCNT1
0034  */
0035 #define RN5T618_ADCCNT3_AUTO BIT(5)
0036 #define RN5T618_ADCEND_IRQ BIT(0)
0037
0038 struct rn5t618_adc_data {
0039     struct device *dev;
0040     struct rn5t618 *rn5t618;
0041     struct completion conv_completion;
0042     int irq;
0043 };
0044
0045 enum rn5t618_channels {
0046     LIMMON = 0,
0047     VBAT,
0048     VADP,
0049     VUSB,
0050     VSYS,
0051     VTHM,
0052     AIN1,
0053     AIN0
0054 };
0055
0056 static const struct u16_fract rn5t618_ratios[8] = {
0057     [LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */
0058     [VBAT] = {2, 1},
0059     [VADP] = {3, 1},
0060     [VUSB] = {3, 1},
0061     [VSYS] = {3, 1},
0062     [VTHM] = {1, 1},
0063     [AIN1] = {1, 1},
0064     [AIN0] = {1, 1},
0065 };
0066
0067 static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val)
0068 {
0069     u8 data[2];
0070     int ret;
0071
0072     ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data));
0073     if (ret < 0)
0074         return ret;
0075
0076     *val = (data[0] << 4) | (data[1] & 0xF);
0077
0078     return 0;
0079 }
0080
0081 static irqreturn_t rn5t618_adc_irq(int irq, void *data)
0082 {
0083     struct rn5t618_adc_data *adc = data;
0084     unsigned int r = 0;
0085     int ret;
0086
0087     /* clear low & high threshold irqs */
0088     regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0);
0089     regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0);
0090
0091     ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r);
0092     if (ret < 0)
0093         dev_err(adc->dev, "failed to read IRQ status: %d\n", ret);
0094
0095     regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0);
0096
0097     if (r & RN5T618_ADCEND_IRQ)
0098         complete(&adc->conv_completion);
0099
0100     return IRQ_HANDLED;
0101 }
0102
0103 static int rn5t618_adc_read(struct iio_dev *iio_dev,
0104                 const struct iio_chan_spec *chan,
0105                 int *val, int *val2, long mask)
0106 {
0107     struct rn5t618_adc_data *adc = iio_priv(iio_dev);
0108     u16 raw;
0109     int ret;
0110
0111     if (mask == IIO_CHAN_INFO_SCALE) {
0112         *val = RN5T618_REFERENCE_VOLT *
0113                rn5t618_ratios[chan->channel].numerator;
0114         *val2 = rn5t618_ratios[chan->channel].denominator * 4095;
0115
0116         return IIO_VAL_FRACTIONAL;
0117     }
0118
0119     /* select channel */
0120     ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
0121                  RN5T618_ADCCNT3_CHANNEL_MASK,
0122                  chan->channel);
0123     if (ret < 0)
0124         return ret;
0125
0126     ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3,
0127                RN5T618_ADCEND_IRQ);
0128     if (ret < 0)
0129         return ret;
0130
0131     ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
0132                  RN5T618_ADCCNT3_AVG,
0133                  mask == IIO_CHAN_INFO_AVERAGE_RAW ?
0134                  RN5T618_ADCCNT3_AVG : 0);
0135     if (ret < 0)
0136         return ret;
0137
0138     init_completion(&adc->conv_completion);
0139     /* single conversion */
0140     ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
0141                  RN5T618_ADCCNT3_GODONE,
0142                  RN5T618_ADCCNT3_GODONE);
0143     if (ret < 0)
0144         return ret;
0145
0146     ret = wait_for_completion_timeout(&adc->conv_completion,
0147                       RN5T618_ADC_CONVERSION_TIMEOUT);
0148     if (ret == 0) {
0149         dev_warn(adc->dev, "timeout waiting for adc result\n");
0150         return -ETIMEDOUT;
0151     }
0152
0153     ret = rn5t618_read_adc_reg(adc->rn5t618,
0154                    RN5T618_ILIMDATAH + 2 * chan->channel,
0155                    &raw);
0156     if (ret < 0)
0157         return ret;
0158
0159     *val = raw;
0160
0161     return IIO_VAL_INT;
0162 }
0163
0164 static const struct iio_info rn5t618_adc_iio_info = {
0165     .read_raw = &rn5t618_adc_read,
0166 };
0167
0168 #define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \
0169     .type = _type, \
0170     .channel = _channel, \
0171     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
0172                   BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
0173                   BIT(IIO_CHAN_INFO_SCALE), \
0174     .datasheet_name = _name, \
0175     .indexed = 1. \
0176 }
0177
0178 static const struct iio_chan_spec rn5t618_adc_iio_channels[] = {
0179     RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"),
0180     RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"),
0181     RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"),
0182     RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"),
0183     RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"),
0184     RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"),
0185     RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"),
0186     RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0")
0187 };
0188
0189 static struct iio_map rn5t618_maps[] = {
0190     IIO_MAP("VADP", "rn5t618-power", "vadp"),
0191     IIO_MAP("VUSB", "rn5t618-power", "vusb"),
0192     { /* sentinel */ }
0193 };
0194
0195 static int rn5t618_adc_probe(struct platform_device *pdev)
0196 {
0197     int ret;
0198     struct iio_dev *iio_dev;
0199     struct rn5t618_adc_data *adc;
0200     struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
0201
0202     iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
0203     if (!iio_dev) {
0204         dev_err(&pdev->dev, "failed allocating iio device\n");
0205         return -ENOMEM;
0206     }
0207
0208     adc = iio_priv(iio_dev);
0209     adc->dev = &pdev->dev;
0210     adc->rn5t618 = rn5t618;
0211
0212     if (rn5t618->irq_data)
0213         adc->irq = regmap_irq_get_virq(rn5t618->irq_data,
0214                            RN5T618_IRQ_ADC);
0215
0216     if (adc->irq <= 0) {
0217         dev_err(&pdev->dev, "get virq failed\n");
0218         return -EINVAL;
0219     }
0220
0221     init_completion(&adc->conv_completion);
0222
0223     iio_dev->name = dev_name(&pdev->dev);
0224     iio_dev->info = &rn5t618_adc_iio_info;
0225     iio_dev->modes = INDIO_DIRECT_MODE;
0226     iio_dev->channels = rn5t618_adc_iio_channels;
0227     iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels);
0228
0229     /* stop any auto-conversion */
0230     ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0);
0231     if (ret < 0)
0232         return ret;
0233
0234     platform_set_drvdata(pdev, iio_dev);
0235
0236     ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL,
0237                     rn5t618_adc_irq,
0238                     IRQF_ONESHOT, dev_name(adc->dev),
0239                     adc);
0240     if (ret < 0) {
0241         dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret);
0242         return ret;
0243     }
0244
0245     ret = devm_iio_map_array_register(adc->dev, iio_dev, rn5t618_maps);
0246     if (ret < 0)
0247         return ret;
0248
0249     return devm_iio_device_register(adc->dev, iio_dev);
0250 }
0251
0252 static struct platform_driver rn5t618_adc_driver = {
0253     .driver = {
0254         .name   = "rn5t618-adc",
0255     },
0256     .probe = rn5t618_adc_probe,
0257 };
0258
0259 module_platform_driver(rn5t618_adc_driver);
0260 MODULE_ALIAS("platform:rn5t618-adc");
0261 MODULE_DESCRIPTION("RICOH RN5T618 ADC driver");
0262 MODULE_LICENSE("GPL");