1 /* 2 * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver 3 * 4 * Copyright (C) 2014 Intel Corporation 5 * 6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; version 2 of the License. 11 * 12 * This program is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * General Public License for more details. 16 * 17 */ 18 19 #include <linux/module.h> 20 #include <linux/kernel.h> 21 #include <linux/device.h> 22 #include <linux/regmap.h> 23 #include <linux/mfd/axp20x.h> 24 #include <linux/platform_device.h> 25 26 #include <linux/iio/iio.h> 27 #include <linux/iio/machine.h> 28 #include <linux/iio/driver.h> 29 30 /* 31 * This mask enables all ADCs except for the battery temp-sensor (TS), that is 32 * left as-is to avoid breaking charging on devices without a temp-sensor. 33 */ 34 #define AXP288_ADC_EN_MASK 0xF0 35 #define AXP288_ADC_TS_ENABLE 0x01 36 37 #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0) 38 #define AXP288_ADC_TS_CURRENT_OFF (0 << 0) 39 #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0) 40 #define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0) 41 #define AXP288_ADC_TS_CURRENT_ON (3 << 0) 42 43 enum axp288_adc_id { 44 AXP288_ADC_TS, 45 AXP288_ADC_PMIC, 46 AXP288_ADC_GP, 47 AXP288_ADC_BATT_CHRG_I, 48 AXP288_ADC_BATT_DISCHRG_I, 49 AXP288_ADC_BATT_V, 50 AXP288_ADC_NR_CHAN, 51 }; 52 53 struct axp288_adc_info { 54 int irq; 55 struct regmap *regmap; 56 bool ts_enabled; 57 }; 58 59 static const struct iio_chan_spec axp288_adc_channels[] = { 60 { 61 .indexed = 1, 62 .type = IIO_TEMP, 63 .channel = 0, 64 .address = AXP288_TS_ADC_H, 65 .datasheet_name = "TS_PIN", 66 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 67 }, { 68 .indexed = 1, 69 .type = IIO_TEMP, 70 .channel = 1, 71 .address = AXP288_PMIC_ADC_H, 72 .datasheet_name = "PMIC_TEMP", 73 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 74 }, { 75 .indexed = 1, 76 .type = IIO_TEMP, 77 .channel = 2, 78 .address = AXP288_GP_ADC_H, 79 .datasheet_name = "GPADC", 80 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 81 }, { 82 .indexed = 1, 83 .type = IIO_CURRENT, 84 .channel = 3, 85 .address = AXP20X_BATT_CHRG_I_H, 86 .datasheet_name = "BATT_CHG_I", 87 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 88 }, { 89 .indexed = 1, 90 .type = IIO_CURRENT, 91 .channel = 4, 92 .address = AXP20X_BATT_DISCHRG_I_H, 93 .datasheet_name = "BATT_DISCHRG_I", 94 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 95 }, { 96 .indexed = 1, 97 .type = IIO_VOLTAGE, 98 .channel = 5, 99 .address = AXP20X_BATT_V_H, 100 .datasheet_name = "BATT_V", 101 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 102 }, 103 }; 104 105 /* for consumer drivers */ 106 static struct iio_map axp288_adc_default_maps[] = { 107 IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"), 108 IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"), 109 IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"), 110 IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"), 111 IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"), 112 IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"), 113 {}, 114 }; 115 116 static int axp288_adc_read_channel(int *val, unsigned long address, 117 struct regmap *regmap) 118 { 119 u8 buf[2]; 120 121 if (regmap_bulk_read(regmap, address, buf, 2)) 122 return -EIO; 123 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F); 124 125 return IIO_VAL_INT; 126 } 127 128 /* 129 * The current-source used for the battery temp-sensor (TS) is shared 130 * with the GPADC. For proper fuel-gauge and charger operation the TS 131 * current-source needs to be permanently on. But to read the GPADC we 132 * need to temporary switch the TS current-source to ondemand, so that 133 * the GPADC can use it, otherwise we will always read an all 0 value. 134 */ 135 static int axp288_adc_set_ts(struct axp288_adc_info *info, 136 unsigned int mode, unsigned long address) 137 { 138 int ret; 139 140 /* No need to switch the current-source if the TS pin is disabled */ 141 if (!info->ts_enabled) 142 return 0; 143 144 /* Channels other than GPADC do not need the current source */ 145 if (address != AXP288_GP_ADC_H) 146 return 0; 147 148 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, 149 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode); 150 if (ret) 151 return ret; 152 153 /* When switching to the GPADC pin give things some time to settle */ 154 if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND) 155 usleep_range(6000, 10000); 156 157 return 0; 158 } 159 160 static int axp288_adc_read_raw(struct iio_dev *indio_dev, 161 struct iio_chan_spec const *chan, 162 int *val, int *val2, long mask) 163 { 164 int ret; 165 struct axp288_adc_info *info = iio_priv(indio_dev); 166 167 mutex_lock(&indio_dev->mlock); 168 switch (mask) { 169 case IIO_CHAN_INFO_RAW: 170 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND, 171 chan->address)) { 172 dev_err(&indio_dev->dev, "GPADC mode\n"); 173 ret = -EINVAL; 174 break; 175 } 176 ret = axp288_adc_read_channel(val, chan->address, info->regmap); 177 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON, 178 chan->address)) 179 dev_err(&indio_dev->dev, "TS pin restore\n"); 180 break; 181 default: 182 ret = -EINVAL; 183 } 184 mutex_unlock(&indio_dev->mlock); 185 186 return ret; 187 } 188 189 static int axp288_adc_initialize(struct axp288_adc_info *info) 190 { 191 int ret, adc_enable_val; 192 193 /* 194 * Determine if the TS pin is enabled and set the TS current-source 195 * accordingly. 196 */ 197 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val); 198 if (ret) 199 return ret; 200 201 if (adc_enable_val & AXP288_ADC_TS_ENABLE) { 202 info->ts_enabled = true; 203 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, 204 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, 205 AXP288_ADC_TS_CURRENT_ON); 206 } else { 207 info->ts_enabled = false; 208 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, 209 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, 210 AXP288_ADC_TS_CURRENT_OFF); 211 } 212 if (ret) 213 return ret; 214 215 /* Turn on the ADC for all channels except TS, leave TS as is */ 216 return regmap_update_bits(info->regmap, AXP20X_ADC_EN1, 217 AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK); 218 } 219 220 static const struct iio_info axp288_adc_iio_info = { 221 .read_raw = &axp288_adc_read_raw, 222 }; 223 224 static int axp288_adc_probe(struct platform_device *pdev) 225 { 226 int ret; 227 struct axp288_adc_info *info; 228 struct iio_dev *indio_dev; 229 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent); 230 231 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info)); 232 if (!indio_dev) 233 return -ENOMEM; 234 235 info = iio_priv(indio_dev); 236 info->irq = platform_get_irq(pdev, 0); 237 if (info->irq < 0) { 238 dev_err(&pdev->dev, "no irq resource?\n"); 239 return info->irq; 240 } 241 platform_set_drvdata(pdev, indio_dev); 242 info->regmap = axp20x->regmap; 243 /* 244 * Set ADC to enabled state at all time, including system suspend. 245 * otherwise internal fuel gauge functionality may be affected. 246 */ 247 ret = axp288_adc_initialize(info); 248 if (ret) { 249 dev_err(&pdev->dev, "unable to enable ADC device\n"); 250 return ret; 251 } 252 253 indio_dev->dev.parent = &pdev->dev; 254 indio_dev->name = pdev->name; 255 indio_dev->channels = axp288_adc_channels; 256 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels); 257 indio_dev->info = &axp288_adc_iio_info; 258 indio_dev->modes = INDIO_DIRECT_MODE; 259 ret = iio_map_array_register(indio_dev, axp288_adc_default_maps); 260 if (ret < 0) 261 return ret; 262 263 ret = iio_device_register(indio_dev); 264 if (ret < 0) { 265 dev_err(&pdev->dev, "unable to register iio device\n"); 266 goto err_array_unregister; 267 } 268 return 0; 269 270 err_array_unregister: 271 iio_map_array_unregister(indio_dev); 272 273 return ret; 274 } 275 276 static int axp288_adc_remove(struct platform_device *pdev) 277 { 278 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 279 280 iio_device_unregister(indio_dev); 281 iio_map_array_unregister(indio_dev); 282 283 return 0; 284 } 285 286 static const struct platform_device_id axp288_adc_id_table[] = { 287 { .name = "axp288_adc" }, 288 {}, 289 }; 290 291 static struct platform_driver axp288_adc_driver = { 292 .probe = axp288_adc_probe, 293 .remove = axp288_adc_remove, 294 .id_table = axp288_adc_id_table, 295 .driver = { 296 .name = "axp288_adc", 297 }, 298 }; 299 300 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table); 301 302 module_platform_driver(axp288_adc_driver); 303 304 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>"); 305 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver"); 306 MODULE_LICENSE("GPL"); 307