1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Support for ON Semiconductor NOA1305 ambient light sensor 4 * 5 * Copyright (C) 2016 Emcraft Systems 6 * Copyright (C) 2019 Collabora Ltd. 7 */ 8 9 #include <linux/delay.h> 10 #include <linux/err.h> 11 #include <linux/i2c.h> 12 #include <linux/iio/iio.h> 13 #include <linux/iio/sysfs.h> 14 #include <linux/module.h> 15 #include <linux/regmap.h> 16 #include <linux/regulator/consumer.h> 17 18 #define NOA1305_REG_POWER_CONTROL 0x0 19 #define NOA1305_POWER_CONTROL_DOWN 0x00 20 #define NOA1305_POWER_CONTROL_ON 0x08 21 #define NOA1305_REG_RESET 0x1 22 #define NOA1305_RESET_RESET 0x10 23 #define NOA1305_REG_INTEGRATION_TIME 0x2 24 #define NOA1305_INTEGR_TIME_800MS 0x00 25 #define NOA1305_INTEGR_TIME_400MS 0x01 26 #define NOA1305_INTEGR_TIME_200MS 0x02 27 #define NOA1305_INTEGR_TIME_100MS 0x03 28 #define NOA1305_INTEGR_TIME_50MS 0x04 29 #define NOA1305_INTEGR_TIME_25MS 0x05 30 #define NOA1305_INTEGR_TIME_12_5MS 0x06 31 #define NOA1305_INTEGR_TIME_6_25MS 0x07 32 #define NOA1305_REG_INT_SELECT 0x3 33 #define NOA1305_INT_SEL_ACTIVE_HIGH 0x01 34 #define NOA1305_INT_SEL_ACTIVE_LOW 0x02 35 #define NOA1305_INT_SEL_INACTIVE 0x03 36 #define NOA1305_REG_INT_THRESH_LSB 0x4 37 #define NOA1305_REG_INT_THRESH_MSB 0x5 38 #define NOA1305_REG_ALS_DATA_LSB 0x6 39 #define NOA1305_REG_ALS_DATA_MSB 0x7 40 #define NOA1305_REG_DEVICE_ID_LSB 0x8 41 #define NOA1305_REG_DEVICE_ID_MSB 0x9 42 43 #define NOA1305_DEVICE_ID 0x0519 44 #define NOA1305_DRIVER_NAME "noa1305" 45 46 struct noa1305_priv { 47 struct i2c_client *client; 48 struct regmap *regmap; 49 }; 50 51 static int noa1305_measure(struct noa1305_priv *priv) 52 { 53 __le16 data; 54 int ret; 55 56 ret = regmap_bulk_read(priv->regmap, NOA1305_REG_ALS_DATA_LSB, &data, 57 2); 58 if (ret < 0) 59 return ret; 60 61 return le16_to_cpu(data); 62 } 63 64 static int noa1305_scale(struct noa1305_priv *priv, int *val, int *val2) 65 { 66 int data; 67 int ret; 68 69 ret = regmap_read(priv->regmap, NOA1305_REG_INTEGRATION_TIME, &data); 70 if (ret < 0) 71 return ret; 72 73 /* 74 * Lux = count / (<Integration Constant> * <Integration Time>) 75 * 76 * Integration Constant = 7.7 77 * Integration Time in Seconds 78 */ 79 switch (data) { 80 case NOA1305_INTEGR_TIME_800MS: 81 *val = 100; 82 *val2 = 77 * 8; 83 break; 84 case NOA1305_INTEGR_TIME_400MS: 85 *val = 100; 86 *val2 = 77 * 4; 87 break; 88 case NOA1305_INTEGR_TIME_200MS: 89 *val = 100; 90 *val2 = 77 * 2; 91 break; 92 case NOA1305_INTEGR_TIME_100MS: 93 *val = 100; 94 *val2 = 77; 95 break; 96 case NOA1305_INTEGR_TIME_50MS: 97 *val = 1000; 98 *val2 = 77 * 5; 99 break; 100 case NOA1305_INTEGR_TIME_25MS: 101 *val = 10000; 102 *val2 = 77 * 25; 103 break; 104 case NOA1305_INTEGR_TIME_12_5MS: 105 *val = 100000; 106 *val2 = 77 * 125; 107 break; 108 case NOA1305_INTEGR_TIME_6_25MS: 109 *val = 1000000; 110 *val2 = 77 * 625; 111 break; 112 default: 113 return -EINVAL; 114 } 115 116 return IIO_VAL_FRACTIONAL; 117 } 118 119 static const struct iio_chan_spec noa1305_channels[] = { 120 { 121 .type = IIO_LIGHT, 122 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 123 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), 124 } 125 }; 126 127 static int noa1305_read_raw(struct iio_dev *indio_dev, 128 struct iio_chan_spec const *chan, 129 int *val, int *val2, long mask) 130 { 131 int ret = -EINVAL; 132 struct noa1305_priv *priv = iio_priv(indio_dev); 133 134 switch (mask) { 135 case IIO_CHAN_INFO_RAW: 136 switch (chan->type) { 137 case IIO_LIGHT: 138 ret = noa1305_measure(priv); 139 if (ret < 0) 140 return ret; 141 *val = ret; 142 return IIO_VAL_INT; 143 default: 144 break; 145 } 146 break; 147 case IIO_CHAN_INFO_SCALE: 148 switch (chan->type) { 149 case IIO_LIGHT: 150 return noa1305_scale(priv, val, val2); 151 default: 152 break; 153 } 154 break; 155 default: 156 break; 157 } 158 159 return ret; 160 } 161 162 static const struct iio_info noa1305_info = { 163 .read_raw = noa1305_read_raw, 164 }; 165 166 static bool noa1305_writable_reg(struct device *dev, unsigned int reg) 167 { 168 switch (reg) { 169 case NOA1305_REG_POWER_CONTROL: 170 case NOA1305_REG_RESET: 171 case NOA1305_REG_INTEGRATION_TIME: 172 case NOA1305_REG_INT_SELECT: 173 case NOA1305_REG_INT_THRESH_LSB: 174 case NOA1305_REG_INT_THRESH_MSB: 175 return true; 176 default: 177 return false; 178 } 179 } 180 181 static const struct regmap_config noa1305_regmap_config = { 182 .name = NOA1305_DRIVER_NAME, 183 .reg_bits = 8, 184 .val_bits = 8, 185 .max_register = NOA1305_REG_DEVICE_ID_MSB, 186 .writeable_reg = noa1305_writable_reg, 187 }; 188 189 static int noa1305_probe(struct i2c_client *client) 190 { 191 struct noa1305_priv *priv; 192 struct iio_dev *indio_dev; 193 struct regmap *regmap; 194 __le16 data; 195 unsigned int dev_id; 196 int ret; 197 198 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*priv)); 199 if (!indio_dev) 200 return -ENOMEM; 201 202 regmap = devm_regmap_init_i2c(client, &noa1305_regmap_config); 203 if (IS_ERR(regmap)) { 204 dev_err(&client->dev, "Regmap initialization failed.\n"); 205 return PTR_ERR(regmap); 206 } 207 208 priv = iio_priv(indio_dev); 209 210 ret = devm_regulator_get_enable(&client->dev, "vin"); 211 if (ret) 212 return dev_err_probe(&client->dev, ret, 213 "get regulator vin failed\n"); 214 215 i2c_set_clientdata(client, indio_dev); 216 priv->client = client; 217 priv->regmap = regmap; 218 219 ret = regmap_bulk_read(regmap, NOA1305_REG_DEVICE_ID_LSB, &data, 2); 220 if (ret < 0) { 221 dev_err(&client->dev, "ID reading failed: %d\n", ret); 222 return ret; 223 } 224 225 dev_id = le16_to_cpu(data); 226 if (dev_id != NOA1305_DEVICE_ID) { 227 dev_err(&client->dev, "Unknown device ID: 0x%x\n", dev_id); 228 return -ENODEV; 229 } 230 231 ret = regmap_write(regmap, NOA1305_REG_POWER_CONTROL, 232 NOA1305_POWER_CONTROL_ON); 233 if (ret < 0) { 234 dev_err(&client->dev, "Enabling power control failed\n"); 235 return ret; 236 } 237 238 ret = regmap_write(regmap, NOA1305_REG_RESET, NOA1305_RESET_RESET); 239 if (ret < 0) { 240 dev_err(&client->dev, "Device reset failed\n"); 241 return ret; 242 } 243 244 ret = regmap_write(regmap, NOA1305_REG_INTEGRATION_TIME, 245 NOA1305_INTEGR_TIME_800MS); 246 if (ret < 0) { 247 dev_err(&client->dev, "Setting integration time failed\n"); 248 return ret; 249 } 250 251 indio_dev->info = &noa1305_info; 252 indio_dev->channels = noa1305_channels; 253 indio_dev->num_channels = ARRAY_SIZE(noa1305_channels); 254 indio_dev->name = NOA1305_DRIVER_NAME; 255 indio_dev->modes = INDIO_DIRECT_MODE; 256 257 ret = devm_iio_device_register(&client->dev, indio_dev); 258 if (ret) 259 dev_err(&client->dev, "registering device failed\n"); 260 261 return ret; 262 } 263 264 static const struct of_device_id noa1305_of_match[] = { 265 { .compatible = "onnn,noa1305" }, 266 { } 267 }; 268 MODULE_DEVICE_TABLE(of, noa1305_of_match); 269 270 static const struct i2c_device_id noa1305_ids[] = { 271 { "noa1305", 0 }, 272 { } 273 }; 274 MODULE_DEVICE_TABLE(i2c, noa1305_ids); 275 276 static struct i2c_driver noa1305_driver = { 277 .driver = { 278 .name = NOA1305_DRIVER_NAME, 279 .of_match_table = noa1305_of_match, 280 }, 281 .probe_new = noa1305_probe, 282 .id_table = noa1305_ids, 283 }; 284 285 module_i2c_driver(noa1305_driver); 286 287 MODULE_AUTHOR("Sergei Miroshnichenko <sergeimir@emcraft.com>"); 288 MODULE_AUTHOR("Martyn Welch <martyn.welch@collabora.com"); 289 MODULE_DESCRIPTION("ON Semiconductor NOA1305 ambient light sensor"); 290 MODULE_LICENSE("GPL"); 291