1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * axp288_adc.c - X-Powers AXP288 PMIC ADC Driver 4 * 5 * Copyright (C) 2014 Intel Corporation 6 * 7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 8 */ 9 10 #include <linux/dmi.h> 11 #include <linux/module.h> 12 #include <linux/kernel.h> 13 #include <linux/device.h> 14 #include <linux/regmap.h> 15 #include <linux/mfd/axp20x.h> 16 #include <linux/platform_device.h> 17 18 #include <linux/iio/iio.h> 19 #include <linux/iio/machine.h> 20 #include <linux/iio/driver.h> 21 22 /* 23 * This mask enables all ADCs except for the battery temp-sensor (TS), that is 24 * left as-is to avoid breaking charging on devices without a temp-sensor. 25 */ 26 #define AXP288_ADC_EN_MASK 0xF0 27 #define AXP288_ADC_TS_ENABLE 0x01 28 29 #define AXP288_ADC_TS_BIAS_MASK GENMASK(5, 4) 30 #define AXP288_ADC_TS_BIAS_20UA (0 << 4) 31 #define AXP288_ADC_TS_BIAS_40UA (1 << 4) 32 #define AXP288_ADC_TS_BIAS_60UA (2 << 4) 33 #define AXP288_ADC_TS_BIAS_80UA (3 << 4) 34 #define AXP288_ADC_TS_CURRENT_ON_OFF_MASK GENMASK(1, 0) 35 #define AXP288_ADC_TS_CURRENT_OFF (0 << 0) 36 #define AXP288_ADC_TS_CURRENT_ON_WHEN_CHARGING (1 << 0) 37 #define AXP288_ADC_TS_CURRENT_ON_ONDEMAND (2 << 0) 38 #define AXP288_ADC_TS_CURRENT_ON (3 << 0) 39 40 enum axp288_adc_id { 41 AXP288_ADC_TS, 42 AXP288_ADC_PMIC, 43 AXP288_ADC_GP, 44 AXP288_ADC_BATT_CHRG_I, 45 AXP288_ADC_BATT_DISCHRG_I, 46 AXP288_ADC_BATT_V, 47 AXP288_ADC_NR_CHAN, 48 }; 49 50 struct axp288_adc_info { 51 int irq; 52 struct regmap *regmap; 53 bool ts_enabled; 54 }; 55 56 static const struct iio_chan_spec axp288_adc_channels[] = { 57 { 58 .indexed = 1, 59 .type = IIO_TEMP, 60 .channel = 0, 61 .address = AXP288_TS_ADC_H, 62 .datasheet_name = "TS_PIN", 63 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 64 }, { 65 .indexed = 1, 66 .type = IIO_TEMP, 67 .channel = 1, 68 .address = AXP288_PMIC_ADC_H, 69 .datasheet_name = "PMIC_TEMP", 70 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 71 }, { 72 .indexed = 1, 73 .type = IIO_TEMP, 74 .channel = 2, 75 .address = AXP288_GP_ADC_H, 76 .datasheet_name = "GPADC", 77 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 78 }, { 79 .indexed = 1, 80 .type = IIO_CURRENT, 81 .channel = 3, 82 .address = AXP20X_BATT_CHRG_I_H, 83 .datasheet_name = "BATT_CHG_I", 84 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 85 }, { 86 .indexed = 1, 87 .type = IIO_CURRENT, 88 .channel = 4, 89 .address = AXP20X_BATT_DISCHRG_I_H, 90 .datasheet_name = "BATT_DISCHRG_I", 91 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 92 }, { 93 .indexed = 1, 94 .type = IIO_VOLTAGE, 95 .channel = 5, 96 .address = AXP20X_BATT_V_H, 97 .datasheet_name = "BATT_V", 98 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 99 }, 100 }; 101 102 /* for consumer drivers */ 103 static struct iio_map axp288_adc_default_maps[] = { 104 IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"), 105 IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"), 106 IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"), 107 IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"), 108 IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"), 109 IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"), 110 {}, 111 }; 112 113 static int axp288_adc_read_channel(int *val, unsigned long address, 114 struct regmap *regmap) 115 { 116 u8 buf[2]; 117 118 if (regmap_bulk_read(regmap, address, buf, 2)) 119 return -EIO; 120 *val = (buf[0] << 4) + ((buf[1] >> 4) & 0x0F); 121 122 return IIO_VAL_INT; 123 } 124 125 /* 126 * The current-source used for the battery temp-sensor (TS) is shared 127 * with the GPADC. For proper fuel-gauge and charger operation the TS 128 * current-source needs to be permanently on. But to read the GPADC we 129 * need to temporary switch the TS current-source to ondemand, so that 130 * the GPADC can use it, otherwise we will always read an all 0 value. 131 */ 132 static int axp288_adc_set_ts(struct axp288_adc_info *info, 133 unsigned int mode, unsigned long address) 134 { 135 int ret; 136 137 /* No need to switch the current-source if the TS pin is disabled */ 138 if (!info->ts_enabled) 139 return 0; 140 141 /* Channels other than GPADC do not need the current source */ 142 if (address != AXP288_GP_ADC_H) 143 return 0; 144 145 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, 146 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, mode); 147 if (ret) 148 return ret; 149 150 /* When switching to the GPADC pin give things some time to settle */ 151 if (mode == AXP288_ADC_TS_CURRENT_ON_ONDEMAND) 152 usleep_range(6000, 10000); 153 154 return 0; 155 } 156 157 static int axp288_adc_read_raw(struct iio_dev *indio_dev, 158 struct iio_chan_spec const *chan, 159 int *val, int *val2, long mask) 160 { 161 int ret; 162 struct axp288_adc_info *info = iio_priv(indio_dev); 163 164 mutex_lock(&indio_dev->mlock); 165 switch (mask) { 166 case IIO_CHAN_INFO_RAW: 167 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND, 168 chan->address)) { 169 dev_err(&indio_dev->dev, "GPADC mode\n"); 170 ret = -EINVAL; 171 break; 172 } 173 ret = axp288_adc_read_channel(val, chan->address, info->regmap); 174 if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON, 175 chan->address)) 176 dev_err(&indio_dev->dev, "TS pin restore\n"); 177 break; 178 default: 179 ret = -EINVAL; 180 } 181 mutex_unlock(&indio_dev->mlock); 182 183 return ret; 184 } 185 186 /* 187 * We rely on the machine's firmware to correctly setup the TS pin bias current 188 * at boot. This lists systems with broken fw where we need to set it ourselves. 189 */ 190 static const struct dmi_system_id axp288_adc_ts_bias_override[] = { 191 { 192 /* Lenovo Ideapad 100S (11 inch) */ 193 .matches = { 194 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), 195 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo ideapad 100S-11IBY"), 196 }, 197 .driver_data = (void *)(uintptr_t)AXP288_ADC_TS_BIAS_80UA, 198 }, 199 {} 200 }; 201 202 static int axp288_adc_initialize(struct axp288_adc_info *info) 203 { 204 const struct dmi_system_id *bias_override; 205 int ret, adc_enable_val; 206 207 bias_override = dmi_first_match(axp288_adc_ts_bias_override); 208 if (bias_override) { 209 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, 210 AXP288_ADC_TS_BIAS_MASK, 211 (uintptr_t)bias_override->driver_data); 212 if (ret) 213 return ret; 214 } 215 216 /* 217 * Determine if the TS pin is enabled and set the TS current-source 218 * accordingly. 219 */ 220 ret = regmap_read(info->regmap, AXP20X_ADC_EN1, &adc_enable_val); 221 if (ret) 222 return ret; 223 224 if (adc_enable_val & AXP288_ADC_TS_ENABLE) { 225 info->ts_enabled = true; 226 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, 227 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, 228 AXP288_ADC_TS_CURRENT_ON); 229 } else { 230 info->ts_enabled = false; 231 ret = regmap_update_bits(info->regmap, AXP288_ADC_TS_PIN_CTRL, 232 AXP288_ADC_TS_CURRENT_ON_OFF_MASK, 233 AXP288_ADC_TS_CURRENT_OFF); 234 } 235 if (ret) 236 return ret; 237 238 /* Turn on the ADC for all channels except TS, leave TS as is */ 239 return regmap_update_bits(info->regmap, AXP20X_ADC_EN1, 240 AXP288_ADC_EN_MASK, AXP288_ADC_EN_MASK); 241 } 242 243 static const struct iio_info axp288_adc_iio_info = { 244 .read_raw = &axp288_adc_read_raw, 245 }; 246 247 static int axp288_adc_probe(struct platform_device *pdev) 248 { 249 int ret; 250 struct axp288_adc_info *info; 251 struct iio_dev *indio_dev; 252 struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent); 253 254 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*info)); 255 if (!indio_dev) 256 return -ENOMEM; 257 258 info = iio_priv(indio_dev); 259 info->irq = platform_get_irq(pdev, 0); 260 if (info->irq < 0) 261 return info->irq; 262 platform_set_drvdata(pdev, indio_dev); 263 info->regmap = axp20x->regmap; 264 /* 265 * Set ADC to enabled state at all time, including system suspend. 266 * otherwise internal fuel gauge functionality may be affected. 267 */ 268 ret = axp288_adc_initialize(info); 269 if (ret) { 270 dev_err(&pdev->dev, "unable to enable ADC device\n"); 271 return ret; 272 } 273 274 indio_dev->name = pdev->name; 275 indio_dev->channels = axp288_adc_channels; 276 indio_dev->num_channels = ARRAY_SIZE(axp288_adc_channels); 277 indio_dev->info = &axp288_adc_iio_info; 278 indio_dev->modes = INDIO_DIRECT_MODE; 279 ret = iio_map_array_register(indio_dev, axp288_adc_default_maps); 280 if (ret < 0) 281 return ret; 282 283 ret = iio_device_register(indio_dev); 284 if (ret < 0) { 285 dev_err(&pdev->dev, "unable to register iio device\n"); 286 goto err_array_unregister; 287 } 288 return 0; 289 290 err_array_unregister: 291 iio_map_array_unregister(indio_dev); 292 293 return ret; 294 } 295 296 static int axp288_adc_remove(struct platform_device *pdev) 297 { 298 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 299 300 iio_device_unregister(indio_dev); 301 iio_map_array_unregister(indio_dev); 302 303 return 0; 304 } 305 306 static const struct platform_device_id axp288_adc_id_table[] = { 307 { .name = "axp288_adc" }, 308 {}, 309 }; 310 311 static struct platform_driver axp288_adc_driver = { 312 .probe = axp288_adc_probe, 313 .remove = axp288_adc_remove, 314 .id_table = axp288_adc_id_table, 315 .driver = { 316 .name = "axp288_adc", 317 }, 318 }; 319 320 MODULE_DEVICE_TABLE(platform, axp288_adc_id_table); 321 322 module_platform_driver(axp288_adc_driver); 323 324 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@linux.intel.com>"); 325 MODULE_DESCRIPTION("X-Powers AXP288 ADC Driver"); 326 MODULE_LICENSE("GPL"); 327