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/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 2500 25 26 /* mask for selecting channels for single conversion */ 27 #define RN5T618_ADCCNT3_CHANNEL_MASK 0x7 28 /* 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 are 33 * in ADCCNT1 34 */ 35 #define RN5T618_ADCCNT3_AUTO BIT(5) 36 #define RN5T618_ADCEND_IRQ BIT(0) 37 38 struct rn5t618_adc_data { 39 struct device *dev; 40 struct rn5t618 *rn5t618; 41 struct completion conv_completion; 42 int irq; 43 }; 44 45 enum rn5t618_channels { 46 LIMMON = 0, 47 VBAT, 48 VADP, 49 VUSB, 50 VSYS, 51 VTHM, 52 AIN1, 53 AIN0 54 }; 55 56 static 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 67 static 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 81 static 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 } 102 103 static 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_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3, 141 RN5T618_ADCCNT3_GODONE, 142 RN5T618_ADCCNT3_GODONE); 143 if (ret < 0) 144 return ret; 145 146 ret = wait_for_completion_timeout(&adc->conv_completion, 147 RN5T618_ADC_CONVERSION_TIMEOUT); 148 if (ret == 0) { 149 dev_warn(adc->dev, "timeout waiting for adc result\n"); 150 return -ETIMEDOUT; 151 } 152 153 ret = rn5t618_read_adc_reg(adc->rn5t618, 154 RN5T618_ILIMDATAH + 2 * chan->channel, 155 &raw); 156 if (ret < 0) 157 return ret; 158 159 *val = raw; 160 161 return IIO_VAL_INT; 162 } 163 164 static const struct iio_info rn5t618_adc_iio_info = { 165 .read_raw = &rn5t618_adc_read, 166 }; 167 168 #define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \ 169 .type = _type, \ 170 .channel = _channel, \ 171 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 172 BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \ 173 BIT(IIO_CHAN_INFO_SCALE), \ 174 .datasheet_name = _name, \ 175 .indexed = 1. \ 176 } 177 178 static const struct iio_chan_spec rn5t618_adc_iio_channels[] = { 179 RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"), 180 RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"), 181 RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"), 182 RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"), 183 RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"), 184 RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"), 185 RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"), 186 RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0") 187 }; 188 189 static struct iio_map rn5t618_maps[] = { 190 IIO_MAP("VADP", "rn5t618-power", "vadp"), 191 IIO_MAP("VUSB", "rn5t618-power", "vusb"), 192 { /* sentinel */ } 193 }; 194 195 static int rn5t618_adc_probe(struct platform_device *pdev) 196 { 197 int ret; 198 struct iio_dev *iio_dev; 199 struct rn5t618_adc_data *adc; 200 struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent); 201 202 iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); 203 if (!iio_dev) { 204 dev_err(&pdev->dev, "failed allocating iio device\n"); 205 return -ENOMEM; 206 } 207 208 adc = iio_priv(iio_dev); 209 adc->dev = &pdev->dev; 210 adc->rn5t618 = rn5t618; 211 212 if (rn5t618->irq_data) 213 adc->irq = regmap_irq_get_virq(rn5t618->irq_data, 214 RN5T618_IRQ_ADC); 215 216 if (adc->irq <= 0) { 217 dev_err(&pdev->dev, "get virq failed\n"); 218 return -EINVAL; 219 } 220 221 init_completion(&adc->conv_completion); 222 223 iio_dev->name = dev_name(&pdev->dev); 224 iio_dev->info = &rn5t618_adc_iio_info; 225 iio_dev->modes = INDIO_DIRECT_MODE; 226 iio_dev->channels = rn5t618_adc_iio_channels; 227 iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels); 228 229 /* stop any auto-conversion */ 230 ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0); 231 if (ret < 0) 232 return ret; 233 234 platform_set_drvdata(pdev, iio_dev); 235 236 ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL, 237 rn5t618_adc_irq, 238 IRQF_ONESHOT, dev_name(adc->dev), 239 adc); 240 if (ret < 0) { 241 dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret); 242 return ret; 243 } 244 245 ret = devm_iio_map_array_register(adc->dev, iio_dev, rn5t618_maps); 246 if (ret < 0) 247 return ret; 248 249 return devm_iio_device_register(adc->dev, iio_dev); 250 } 251 252 static struct platform_driver rn5t618_adc_driver = { 253 .driver = { 254 .name = "rn5t618-adc", 255 }, 256 .probe = rn5t618_adc_probe, 257 }; 258 259 module_platform_driver(rn5t618_adc_driver); 260 MODULE_ALIAS("platform:rn5t618-adc"); 261 MODULE_DESCRIPTION("RICOH RN5T618 ADC driver"); 262 MODULE_LICENSE("GPL"); 263