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/of.h> 21 22 #include <linux/iio/iio.h> 23 #include <linux/iio/sysfs.h> 24 25 #define AL3010_DRV_NAME "al3010" 26 27 #define AL3010_REG_SYSTEM 0x00 28 #define AL3010_REG_DATA_LOW 0x0c 29 #define AL3010_REG_CONFIG 0x10 30 31 #define AL3010_CONFIG_DISABLE 0x00 32 #define AL3010_CONFIG_ENABLE 0x01 33 34 #define AL3010_GAIN_MASK GENMASK(6,4) 35 36 #define AL3010_SCALE_AVAILABLE "1.1872 0.2968 0.0742 0.018" 37 38 enum al3xxxx_range { 39 AL3XXX_RANGE_1, /* 77806 lx */ 40 AL3XXX_RANGE_2, /* 19542 lx */ 41 AL3XXX_RANGE_3, /* 4863 lx */ 42 AL3XXX_RANGE_4 /* 1216 lx */ 43 }; 44 45 static const int al3010_scales[][2] = { 46 {0, 1187200}, {0, 296800}, {0, 74200}, {0, 18600} 47 }; 48 49 struct al3010_data { 50 struct i2c_client *client; 51 }; 52 53 static const struct iio_chan_spec al3010_channels[] = { 54 { 55 .type = IIO_LIGHT, 56 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 57 BIT(IIO_CHAN_INFO_SCALE), 58 } 59 }; 60 61 static IIO_CONST_ATTR(in_illuminance_scale_available, AL3010_SCALE_AVAILABLE); 62 63 static struct attribute *al3010_attributes[] = { 64 &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, 65 NULL, 66 }; 67 68 static const struct attribute_group al3010_attribute_group = { 69 .attrs = al3010_attributes, 70 }; 71 72 static int al3010_set_pwr(struct i2c_client *client, bool pwr) 73 { 74 u8 val = pwr ? AL3010_CONFIG_ENABLE : AL3010_CONFIG_DISABLE; 75 return i2c_smbus_write_byte_data(client, AL3010_REG_SYSTEM, val); 76 } 77 78 static void al3010_set_pwr_off(void *_data) 79 { 80 struct al3010_data *data = _data; 81 82 al3010_set_pwr(data->client, false); 83 } 84 85 static int al3010_init(struct al3010_data *data) 86 { 87 int ret; 88 89 ret = al3010_set_pwr(data->client, true); 90 91 if (ret < 0) 92 return ret; 93 94 ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG, 95 FIELD_PREP(AL3010_GAIN_MASK, 96 AL3XXX_RANGE_3)); 97 if (ret < 0) 98 return ret; 99 100 return 0; 101 } 102 103 static int al3010_read_raw(struct iio_dev *indio_dev, 104 struct iio_chan_spec const *chan, int *val, 105 int *val2, long mask) 106 { 107 struct al3010_data *data = iio_priv(indio_dev); 108 int ret; 109 110 switch (mask) { 111 case IIO_CHAN_INFO_RAW: 112 /* 113 * ALS ADC value is stored in two adjacent registers: 114 * - low byte of output is stored at AL3010_REG_DATA_LOW 115 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1 116 */ 117 ret = i2c_smbus_read_word_data(data->client, 118 AL3010_REG_DATA_LOW); 119 if (ret < 0) 120 return ret; 121 *val = ret; 122 return IIO_VAL_INT; 123 case IIO_CHAN_INFO_SCALE: 124 ret = i2c_smbus_read_byte_data(data->client, 125 AL3010_REG_CONFIG); 126 if (ret < 0) 127 return ret; 128 129 ret = FIELD_GET(AL3010_GAIN_MASK, ret); 130 *val = al3010_scales[ret][0]; 131 *val2 = al3010_scales[ret][1]; 132 133 return IIO_VAL_INT_PLUS_MICRO; 134 } 135 return -EINVAL; 136 } 137 138 static int al3010_write_raw(struct iio_dev *indio_dev, 139 struct iio_chan_spec const *chan, int val, 140 int val2, long mask) 141 { 142 struct al3010_data *data = iio_priv(indio_dev); 143 int i; 144 145 switch (mask) { 146 case IIO_CHAN_INFO_SCALE: 147 for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) { 148 if (val != al3010_scales[i][0] || 149 val2 != al3010_scales[i][1]) 150 continue; 151 152 return i2c_smbus_write_byte_data(data->client, 153 AL3010_REG_CONFIG, 154 FIELD_PREP(AL3010_GAIN_MASK, i)); 155 } 156 break; 157 } 158 return -EINVAL; 159 } 160 161 static const struct iio_info al3010_info = { 162 .read_raw = al3010_read_raw, 163 .write_raw = al3010_write_raw, 164 .attrs = &al3010_attribute_group, 165 }; 166 167 static int al3010_probe(struct i2c_client *client, 168 const struct i2c_device_id *id) 169 { 170 struct al3010_data *data; 171 struct iio_dev *indio_dev; 172 int ret; 173 174 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 175 if (!indio_dev) 176 return -ENOMEM; 177 178 data = iio_priv(indio_dev); 179 i2c_set_clientdata(client, indio_dev); 180 data->client = client; 181 182 indio_dev->info = &al3010_info; 183 indio_dev->name = AL3010_DRV_NAME; 184 indio_dev->channels = al3010_channels; 185 indio_dev->num_channels = ARRAY_SIZE(al3010_channels); 186 indio_dev->modes = INDIO_DIRECT_MODE; 187 188 ret = al3010_init(data); 189 if (ret < 0) { 190 dev_err(&client->dev, "al3010 chip init failed\n"); 191 return ret; 192 } 193 194 ret = devm_add_action_or_reset(&client->dev, 195 al3010_set_pwr_off, 196 data); 197 if (ret < 0) 198 return ret; 199 200 return devm_iio_device_register(&client->dev, indio_dev); 201 } 202 203 static int al3010_suspend(struct device *dev) 204 { 205 return al3010_set_pwr(to_i2c_client(dev), false); 206 } 207 208 static int al3010_resume(struct device *dev) 209 { 210 return al3010_set_pwr(to_i2c_client(dev), true); 211 } 212 213 static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume); 214 215 static const struct i2c_device_id al3010_id[] = { 216 {"al3010", }, 217 {} 218 }; 219 MODULE_DEVICE_TABLE(i2c, al3010_id); 220 221 static const struct of_device_id al3010_of_match[] = { 222 { .compatible = "dynaimage,al3010", }, 223 {}, 224 }; 225 MODULE_DEVICE_TABLE(of, al3010_of_match); 226 227 static struct i2c_driver al3010_driver = { 228 .driver = { 229 .name = AL3010_DRV_NAME, 230 .of_match_table = al3010_of_match, 231 .pm = pm_sleep_ptr(&al3010_pm_ops), 232 }, 233 .probe = al3010_probe, 234 .id_table = al3010_id, 235 }; 236 module_i2c_driver(al3010_driver); 237 238 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>"); 239 MODULE_AUTHOR("David Heidelberg <david@ixit.cz>"); 240 MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver"); 241 MODULE_LICENSE("GPL v2"); 242