1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * ADC driver for the RICOH RN5T618 power management chip family 4 * 5 * Copyright (C) 2019 Andreas Kemnade 6 */ 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/slab.h> 20 21 #define RN5T618_ADC_CONVERSION_TIMEOUT (msecs_to_jiffies(500)) 22 #define RN5T618_REFERENCE_VOLT 2500 23 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 31 * in ADCCNT1 32 */ 33 #define RN5T618_ADCCNT3_AUTO BIT(5) 34 #define RN5T618_ADCEND_IRQ BIT(0) 35 36 struct rn5t618_adc_data { 37 struct device *dev; 38 struct rn5t618 *rn5t618; 39 struct completion conv_completion; 40 int irq; 41 }; 42 43 struct rn5t618_channel_ratios { 44 u16 numerator; 45 u16 denominator; 46 }; 47 48 enum rn5t618_channels { 49 LIMMON = 0, 50 VBAT, 51 VADP, 52 VUSB, 53 VSYS, 54 VTHM, 55 AIN1, 56 AIN0 57 }; 58 59 static const struct rn5t618_channel_ratios rn5t618_ratios[8] = { 60 [LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */ 61 [VBAT] = {2, 1}, 62 [VADP] = {3, 1}, 63 [VUSB] = {3, 1}, 64 [VSYS] = {3, 1}, 65 [VTHM] = {1, 1}, 66 [AIN1] = {1, 1}, 67 [AIN0] = {1, 1}, 68 }; 69 70 static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val) 71 { 72 u8 data[2]; 73 int ret; 74 75 ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data)); 76 if (ret < 0) 77 return ret; 78 79 *val = (data[0] << 4) | (data[1] & 0xF); 80 81 return 0; 82 } 83 84 static irqreturn_t rn5t618_adc_irq(int irq, void *data) 85 { 86 struct rn5t618_adc_data *adc = data; 87 unsigned int r = 0; 88 int ret; 89 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); 93 94 ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r); 95 if (ret < 0) 96 dev_err(adc->dev, "failed to read IRQ status: %d\n", ret); 97 98 regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0); 99 100 if (r & RN5T618_ADCEND_IRQ) 101 complete(&adc->conv_completion); 102 103 return IRQ_HANDLED; 104 } 105 106 static int rn5t618_adc_read(struct iio_dev *iio_dev, 107 const struct iio_chan_spec *chan, 108 int *val, int *val2, long mask) 109 { 110 struct rn5t618_adc_data *adc = iio_priv(iio_dev); 111 u16 raw; 112 int ret; 113 114 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; 118 119 return IIO_VAL_FRACTIONAL; 120 } 121 122 /* select channel */ 123 ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, 124 RN5T618_ADCCNT3_CHANNEL_MASK, 125 chan->channel); 126 if (ret < 0) 127 return ret; 128 129 ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3, 130 RN5T618_ADCEND_IRQ); 131 if (ret < 0) 132 return ret; 133 134 ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, 135 RN5T618_ADCCNT3_AVG, 136 mask == IIO_CHAN_INFO_AVERAGE_RAW ? 137 RN5T618_ADCCNT3_AVG : 0); 138 if (ret < 0) 139 return ret; 140 141 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); 146 if (ret < 0) 147 return ret; 148 149 ret = wait_for_completion_timeout(&adc->conv_completion, 150 RN5T618_ADC_CONVERSION_TIMEOUT); 151 if (ret == 0) { 152 dev_warn(adc->dev, "timeout waiting for adc result\n"); 153 return -ETIMEDOUT; 154 } 155 156 ret = rn5t618_read_adc_reg(adc->rn5t618, 157 RN5T618_ILIMDATAH + 2 * chan->channel, 158 &raw); 159 if (ret < 0) 160 return ret; 161 162 *val = raw; 163 164 return IIO_VAL_INT; 165 } 166 167 static const struct iio_info rn5t618_adc_iio_info = { 168 .read_raw = &rn5t618_adc_read, 169 }; 170 171 #define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \ 172 .type = _type, \ 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, \ 178 .indexed = 1. \ 179 } 180 181 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") 190 }; 191 192 static int rn5t618_adc_probe(struct platform_device *pdev) 193 { 194 int ret; 195 struct iio_dev *iio_dev; 196 struct rn5t618_adc_data *adc; 197 struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent); 198 199 iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); 200 if (!iio_dev) { 201 dev_err(&pdev->dev, "failed allocating iio device\n"); 202 return -ENOMEM; 203 } 204 205 adc = iio_priv(iio_dev); 206 adc->dev = &pdev->dev; 207 adc->rn5t618 = rn5t618; 208 209 if (rn5t618->irq_data) 210 adc->irq = regmap_irq_get_virq(rn5t618->irq_data, 211 RN5T618_IRQ_ADC); 212 213 if (adc->irq <= 0) { 214 dev_err(&pdev->dev, "get virq failed\n"); 215 return -EINVAL; 216 } 217 218 init_completion(&adc->conv_completion); 219 220 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); 225 226 /* stop any auto-conversion */ 227 ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0); 228 if (ret < 0) 229 return ret; 230 231 platform_set_drvdata(pdev, iio_dev); 232 233 ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL, 234 rn5t618_adc_irq, 235 IRQF_ONESHOT, dev_name(adc->dev), 236 adc); 237 if (ret < 0) { 238 dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret); 239 return ret; 240 } 241 242 return devm_iio_device_register(adc->dev, iio_dev); 243 } 244 245 static struct platform_driver rn5t618_adc_driver = { 246 .driver = { 247 .name = "rn5t618-adc", 248 }, 249 .probe = rn5t618_adc_probe, 250 }; 251 252 module_platform_driver(rn5t618_adc_driver); 253 MODULE_ALIAS("platform:rn5t618-adc"); 254 MODULE_DESCRIPTION("RICOH RN5T618 ADC driver"); 255 MODULE_LICENSE("GPL"); 256