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/mod_devicetable.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 if (ret < 0) 91 return ret; 92 93 ret = devm_add_action_or_reset(&data->client->dev, 94 al3010_set_pwr_off, 95 data); 96 if (ret < 0) 97 return ret; 98 99 ret = i2c_smbus_write_byte_data(data->client, AL3010_REG_CONFIG, 100 FIELD_PREP(AL3010_GAIN_MASK, 101 AL3XXX_RANGE_3)); 102 if (ret < 0) 103 return ret; 104 105 return 0; 106 } 107 108 static int al3010_read_raw(struct iio_dev *indio_dev, 109 struct iio_chan_spec const *chan, int *val, 110 int *val2, long mask) 111 { 112 struct al3010_data *data = iio_priv(indio_dev); 113 int ret; 114 115 switch (mask) { 116 case IIO_CHAN_INFO_RAW: 117 /* 118 * ALS ADC value is stored in two adjacent registers: 119 * - low byte of output is stored at AL3010_REG_DATA_LOW 120 * - high byte of output is stored at AL3010_REG_DATA_LOW + 1 121 */ 122 ret = i2c_smbus_read_word_data(data->client, 123 AL3010_REG_DATA_LOW); 124 if (ret < 0) 125 return ret; 126 *val = ret; 127 return IIO_VAL_INT; 128 case IIO_CHAN_INFO_SCALE: 129 ret = i2c_smbus_read_byte_data(data->client, 130 AL3010_REG_CONFIG); 131 if (ret < 0) 132 return ret; 133 134 ret = FIELD_GET(AL3010_GAIN_MASK, ret); 135 *val = al3010_scales[ret][0]; 136 *val2 = al3010_scales[ret][1]; 137 138 return IIO_VAL_INT_PLUS_MICRO; 139 } 140 return -EINVAL; 141 } 142 143 static int al3010_write_raw(struct iio_dev *indio_dev, 144 struct iio_chan_spec const *chan, int val, 145 int val2, long mask) 146 { 147 struct al3010_data *data = iio_priv(indio_dev); 148 int i; 149 150 switch (mask) { 151 case IIO_CHAN_INFO_SCALE: 152 for (i = 0; i < ARRAY_SIZE(al3010_scales); i++) { 153 if (val != al3010_scales[i][0] || 154 val2 != al3010_scales[i][1]) 155 continue; 156 157 return i2c_smbus_write_byte_data(data->client, 158 AL3010_REG_CONFIG, 159 FIELD_PREP(AL3010_GAIN_MASK, i)); 160 } 161 break; 162 } 163 return -EINVAL; 164 } 165 166 static const struct iio_info al3010_info = { 167 .read_raw = al3010_read_raw, 168 .write_raw = al3010_write_raw, 169 .attrs = &al3010_attribute_group, 170 }; 171 172 static int al3010_probe(struct i2c_client *client) 173 { 174 struct al3010_data *data; 175 struct iio_dev *indio_dev; 176 int ret; 177 178 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 179 if (!indio_dev) 180 return -ENOMEM; 181 182 data = iio_priv(indio_dev); 183 i2c_set_clientdata(client, indio_dev); 184 data->client = client; 185 186 indio_dev->info = &al3010_info; 187 indio_dev->name = AL3010_DRV_NAME; 188 indio_dev->channels = al3010_channels; 189 indio_dev->num_channels = ARRAY_SIZE(al3010_channels); 190 indio_dev->modes = INDIO_DIRECT_MODE; 191 192 ret = al3010_init(data); 193 if (ret < 0) { 194 dev_err(&client->dev, "al3010 chip init failed\n"); 195 return ret; 196 } 197 198 return devm_iio_device_register(&client->dev, indio_dev); 199 } 200 201 static int al3010_suspend(struct device *dev) 202 { 203 return al3010_set_pwr(to_i2c_client(dev), false); 204 } 205 206 static int al3010_resume(struct device *dev) 207 { 208 return al3010_set_pwr(to_i2c_client(dev), true); 209 } 210 211 static DEFINE_SIMPLE_DEV_PM_OPS(al3010_pm_ops, al3010_suspend, al3010_resume); 212 213 static const struct i2c_device_id al3010_id[] = { 214 {"al3010", }, 215 {} 216 }; 217 MODULE_DEVICE_TABLE(i2c, al3010_id); 218 219 static const struct of_device_id al3010_of_match[] = { 220 { .compatible = "dynaimage,al3010", }, 221 {}, 222 }; 223 MODULE_DEVICE_TABLE(of, al3010_of_match); 224 225 static struct i2c_driver al3010_driver = { 226 .driver = { 227 .name = AL3010_DRV_NAME, 228 .of_match_table = al3010_of_match, 229 .pm = pm_sleep_ptr(&al3010_pm_ops), 230 }, 231 .probe = al3010_probe, 232 .id_table = al3010_id, 233 }; 234 module_i2c_driver(al3010_driver); 235 236 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>"); 237 MODULE_AUTHOR("David Heidelberg <david@ixit.cz>"); 238 MODULE_DESCRIPTION("AL3010 Ambient Light Sensor driver"); 239 MODULE_LICENSE("GPL v2"); 240