1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AL3010 - Dyna Image Ambient Light Sensor 4 * 5 * Copyright (c) 2014, Intel Corporation. 6 * Copyright (c) 2016, Dyna-Image Corp. 7 * Copyright (c) 2020, David Heidelberg, Michał Mirosław, Dmitry Osipenko 8 * 9 * IIO driver for AL3010 (7-bit I2C slave address 0x1C). 10 * 11 * TODO: interrupt support, thresholds 12 * When the driver will get support for interrupt handling, then interrupt 13 * will need to be disabled before turning sensor OFF in order to avoid 14 * potential races with the interrupt handling. 15 */ 16 17 #include <linux/bitfield.h> 18 #include <linux/i2c.h> 19 #include <linux/module.h> 20 #include <linux/regmap.h> 21 #include <linux/mod_devicetable.h> 22 23 #include <linux/iio/iio.h> 24 #include <linux/iio/sysfs.h> 25 26 #define AL3010_REG_SYSTEM 0x00 27 #define AL3010_REG_DATA_LOW 0x0c 28 #define AL3010_REG_CONFIG 0x10 29 30 #define AL3010_CONFIG_DISABLE 0x00 31 #define AL3010_CONFIG_ENABLE 0x01 32 33 #define AL3010_GAIN_MASK GENMASK(6,4) 34 35 #define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018" 36 37 enum al3xxxx_range { 38 AL3XXX_RANGE_1, /* 77806 lx */ 39 AL3XXX_RANGE_2, /* 19542 lx */ 40 AL3XXX_RANGE_3, /* 4863 lx */ 41 AL3XXX_RANGE_4 /* 1216 lx */ 42 }; 43 44 static const int al3010_scales[][2] = { 45 {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600} 46 }; 47 48 static const struct regmap_config al3010_regmap_config = { 49 .reg_bits = 8, 50 .val_bits = 8, 51 .max_register = AL3010_REG_CONFIG, 52 }; 53 54 struct al3010_data { 55 struct regmap *regmap; 56 }; 57 58 static const struct iio_chan_spec al3010_channels[] = { 59 { 60 .type = IIO_LIGHT, 61 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 62 BIT(IIO_CHAN_INFO_SCALE), 63 } 64 }; 65 66 static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE); 67 68 static struct attribute *al3010_attributes[] = { 69 &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, 70 NULL, 71 }; 72 73 static const struct attribute_group al3010_attribute_group = { 74 .attrs = al3010_attributes, 75 }; 76 77 static int al3010_set_pwr_on(struct al3010_data *data) 78 { 79 return regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_ENABLE); 80 } 81 82 static void al3010_set_pwr_off(void *_data) 83 { 84 struct al3010_data *data = _data; 85 struct device *dev = regmap_get_device(data->regmap); 86 int ret; 87 88 ret = regmap_write(data->regmap, AL3010_REG_SYSTEM, AL3010_CONFIG_DISABLE); 89 if (ret) 90 dev_err(dev, "failed to write system register\n"); 91 } 92 93 static int al3010_init(struct al3010_data *data) 94 { 95 struct device *dev = regmap_get_device(data->regmap); 96 int ret; 97 98 ret = al3010_set_pwr_on(data); 99 if (ret) 100 return ret; 101 102 ret = devm_add_action_or_reset(dev, al3010_set_pwr_off, data); 103 if (ret) 104 return ret; 105 return regmap_write(data->regmap, AL3010_REG_CONFIG, 106 FIELD_PREP(AL3010_GAIN_MASK, AL3XXX_RANGE_3)); 107 } 108 109 static int al3010_read_raw(struct iio_dev *indio_dev, 110 struct iio_chan_spec const *chan, int *val, 111 int *val2, long mask) 112 { 113 struct al3010_data *data = iio_priv(indio_dev); 114 int ret, gain; 115 __le16 raw; 116 117 switch (mask) { 118 case IIO_CHAN_INFO_RAW: 119 /* 120 * ALS ADC value is stored in two adjacent registers: 121 * - low byte of output is stored at AL3010_REG_DATA_LOW 122 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1 123 */ 124 ret = regmap_bulk_read(data->regmap, AL3010_REG_DATA_LOW, 125 &raw, sizeof(raw)); 126 if (ret) 127 return ret; 128 129 *val = le16_to_cpu(raw); 130 131 return IIO_VAL_INT; 132 case IIO_CHAN_INFO_SCALE: 133 ret = regmap_read(data->regmap, AL3010_REG_CONFIG, &gain); 134 if (ret) 135 return ret; 136 137 gain = FIELD_GET(AL3010_GAIN_MASK, gain); 138 *val = al3010_scales[gain][0]; 139 *val2 = al3010_scales[gain][1]; 140 141 return IIO_VAL_INT_PLUS_MICRO; 142 } 143 return -EINVAL; 144 } 145 146 static int al3010_write_raw(struct iio_dev *indio_dev, 147 struct iio_chan_spec const *chan, int val, 148 int val2, long mask) 149 { 150 struct al3010_data *data = iio_priv(indio_dev); 151 unsigned int i; 152 153 switch (mask) { 154 case IIO_CHAN_INFO_SCALE: 155 for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) { 156 if (val != al3010_scales[i][0] || 157 val2 != al3010_scales[i][1]) 158 continue; 159 160 return regmap_write(data->regmap, AL3010_REG_CONFIG, 161 FIELD_PREP(AL3010_GAIN_MASK, i)); 162 } 163 break; 164 } 165 return -EINVAL; 166 } 167 168 static const struct iio_info al3010_info = { 169 .read_raw = al3010_read_raw, 170 .write_raw = al3010_write_raw, 171 .attrs = &al3010_attribute_group, 172 }; 173 174 static int al3010_probe(struct i2c_client *client) 175 { 176 struct al3010_data *data; 177 struct device *dev = &client->dev; 178 struct iio_dev *indio_dev; 179 int ret; 180 181 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 182 if (!indio_dev) 183 return -ENOMEM; 184 185 data = iio_priv(indio_dev); 186 i2c_set_clientdata(client, indio_dev); 187 data->regmap = devm_regmap_init_i2c(client, &al3010_regmap_config); 188 if (IS_ERR(data->regmap)) 189 return dev_err_probe(dev, PTR_ERR(data->regmap), 190 "cannot allocate regmap\n"); 191 192 indio_dev->info = &al3010_info; 193 indio_dev->name = "al3010"; 194 indio_dev->channels = al3010_channels; 195 indio_dev->num_channels = ARRAY_SIZE(al3010_channels); 196 indio_dev->modes = INDIO_DIRECT_MODE; 197 198 ret = al3010_init(data); 199 if (ret) 200 return dev_err_probe(dev, ret, "failed to init ALS\n"); 201 202 return devm_iio_device_register(dev, indio_dev); 203 } 204 205 static int al3010_suspend(struct device *dev) 206 { 207 struct al3010_data *data = iio_priv(dev_get_drvdata(dev)); 208 209 al3010_set_pwr_off(data); 210 return 0; 211 } 212 213 static int al3010_resume(struct device *dev) 214 { 215 struct al3010_data *data = iio_priv(dev_get_drvdata(dev)); 216 217 return al3010_set_pwr_on(data); 218 } 219 220 static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume); 221 222 static const struct i2c_device_id al3010_id[] = { 223 { .name = "al3010" }, 224 { } 225 }; 226 MODULE_DEVICE_TABLE(i2c, al3010_id); 227 228 static const struct of_device_id al3010_of_match[] = { 229 { .compatible = "dynaimage,al3010", }, 230 { } 231 }; 232 MODULE_DEVICE_TABLE(of, al3010_of_match); 233 234 static struct i2c_driver al3010_driver = { 235 .driver = { 236 .name = "al3010", 237 .of_match_table = al3010_of_match, 238 .pm = pm_sleep_ptr(&al3010_pm_ops), 239 }, 240 .probe = al3010_probe, 241 .id_table = al3010_id, 242 }; 243 module_i2c_driver(al3010_driver); 244 245 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>"); 246 MODULE_AUTHOR("David Heidelberg <david@ixit.cz>"); 247 MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver"); 248 MODULE_LICENSE("GPL v2"); 249