Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 1 | /* |
| 2 | * AL3320A - Dyna Image Ambient Light Sensor |
| 3 | * |
| 4 | * Copyright (c) 2014, Intel Corporation. |
| 5 | * |
| 6 | * This file is subject to the terms and conditions of version 2 of |
| 7 | * the GNU General Public License. See the file COPYING in the main |
| 8 | * directory of this archive for more details. |
| 9 | * |
| 10 | * IIO driver for AL3320A (7-bit I2C slave address 0x1C). |
| 11 | * |
| 12 | * TODO: interrupt support, thresholds |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/i2c.h> |
| 19 | |
| 20 | #include <linux/iio/iio.h> |
| 21 | #include <linux/iio/sysfs.h> |
| 22 | |
| 23 | #define AL3320A_DRV_NAME "al3320a" |
| 24 | |
| 25 | #define AL3320A_REG_CONFIG 0x00 |
| 26 | #define AL3320A_REG_STATUS 0x01 |
| 27 | #define AL3320A_REG_INT 0x02 |
| 28 | #define AL3320A_REG_WAIT 0x06 |
| 29 | #define AL3320A_REG_CONFIG_RANGE 0x07 |
| 30 | #define AL3320A_REG_PERSIST 0x08 |
| 31 | #define AL3320A_REG_MEAN_TIME 0x09 |
| 32 | #define AL3320A_REG_ADUMMY 0x0A |
| 33 | #define AL3320A_REG_DATA_LOW 0x22 |
| 34 | |
| 35 | #define AL3320A_REG_LOW_THRESH_LOW 0x30 |
| 36 | #define AL3320A_REG_LOW_THRESH_HIGH 0x31 |
| 37 | #define AL3320A_REG_HIGH_THRESH_LOW 0x32 |
| 38 | #define AL3320A_REG_HIGH_THRESH_HIGH 0x33 |
| 39 | |
| 40 | #define AL3320A_CONFIG_DISABLE 0x00 |
| 41 | #define AL3320A_CONFIG_ENABLE 0x01 |
| 42 | |
| 43 | #define AL3320A_GAIN_SHIFT 1 |
| 44 | #define AL3320A_GAIN_MASK (BIT(2) | BIT(1)) |
| 45 | |
| 46 | /* chip params default values */ |
| 47 | #define AL3320A_DEFAULT_MEAN_TIME 4 |
| 48 | #define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */ |
| 49 | |
| 50 | #define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01" |
| 51 | |
| 52 | enum al3320a_range { |
| 53 | AL3320A_RANGE_1, /* 33.28 Klx */ |
| 54 | AL3320A_RANGE_2, /* 8.32 Klx */ |
| 55 | AL3320A_RANGE_3, /* 2.08 Klx */ |
| 56 | AL3320A_RANGE_4 /* 0.65 Klx */ |
| 57 | }; |
| 58 | |
| 59 | static const int al3320a_scales[][2] = { |
| 60 | {0, 512000}, {0, 128000}, {0, 32000}, {0, 10000} |
| 61 | }; |
| 62 | |
| 63 | struct al3320a_data { |
| 64 | struct i2c_client *client; |
| 65 | }; |
| 66 | |
| 67 | static const struct iio_chan_spec al3320a_channels[] = { |
| 68 | { |
| 69 | .type = IIO_LIGHT, |
| 70 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
| 71 | BIT(IIO_CHAN_INFO_SCALE), |
| 72 | } |
| 73 | }; |
| 74 | |
| 75 | static IIO_CONST_ATTR(in_illuminance_scale_available, AL3320A_SCALE_AVAILABLE); |
| 76 | |
| 77 | static struct attribute *al3320a_attributes[] = { |
| 78 | &iio_const_attr_in_illuminance_scale_available.dev_attr.attr, |
| 79 | NULL, |
| 80 | }; |
| 81 | |
| 82 | static const struct attribute_group al3320a_attribute_group = { |
| 83 | .attrs = al3320a_attributes, |
| 84 | }; |
| 85 | |
| 86 | static int al3320a_init(struct al3320a_data *data) |
| 87 | { |
| 88 | int ret; |
| 89 | |
| 90 | /* power on */ |
| 91 | ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG, |
| 92 | AL3320A_CONFIG_ENABLE); |
| 93 | if (ret < 0) |
| 94 | return ret; |
| 95 | |
| 96 | ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE, |
| 97 | AL3320A_RANGE_3 << AL3320A_GAIN_SHIFT); |
| 98 | if (ret < 0) |
| 99 | return ret; |
| 100 | |
| 101 | ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME, |
| 102 | AL3320A_DEFAULT_MEAN_TIME); |
| 103 | if (ret < 0) |
| 104 | return ret; |
| 105 | |
| 106 | ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT, |
| 107 | AL3320A_DEFAULT_WAIT_TIME); |
| 108 | if (ret < 0) |
| 109 | return ret; |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | static int al3320a_read_raw(struct iio_dev *indio_dev, |
| 115 | struct iio_chan_spec const *chan, int *val, |
| 116 | int *val2, long mask) |
| 117 | { |
| 118 | struct al3320a_data *data = iio_priv(indio_dev); |
| 119 | int ret; |
| 120 | |
| 121 | switch (mask) { |
| 122 | case IIO_CHAN_INFO_RAW: |
| 123 | /* |
| 124 | * ALS ADC value is stored in two adjacent registers: |
| 125 | * - low byte of output is stored at AL3320A_REG_DATA_LOW |
| 126 | * - high byte of output is stored at AL3320A_REG_DATA_LOW + 1 |
| 127 | */ |
| 128 | ret = i2c_smbus_read_word_data(data->client, |
| 129 | AL3320A_REG_DATA_LOW); |
| 130 | if (ret < 0) |
| 131 | return ret; |
| 132 | *val = ret; |
| 133 | return IIO_VAL_INT; |
| 134 | case IIO_CHAN_INFO_SCALE: |
| 135 | ret = i2c_smbus_read_byte_data(data->client, |
| 136 | AL3320A_REG_CONFIG_RANGE); |
| 137 | if (ret < 0) |
| 138 | return ret; |
| 139 | |
| 140 | ret = (ret & AL3320A_GAIN_MASK) >> AL3320A_GAIN_SHIFT; |
| 141 | *val = al3320a_scales[ret][0]; |
| 142 | *val2 = al3320a_scales[ret][1]; |
| 143 | |
| 144 | return IIO_VAL_INT_PLUS_MICRO; |
| 145 | } |
| 146 | return -EINVAL; |
| 147 | } |
| 148 | |
| 149 | static int al3320a_write_raw(struct iio_dev *indio_dev, |
| 150 | struct iio_chan_spec const *chan, int val, |
| 151 | int val2, long mask) |
| 152 | { |
| 153 | struct al3320a_data *data = iio_priv(indio_dev); |
| 154 | int i; |
| 155 | |
| 156 | switch (mask) { |
| 157 | case IIO_CHAN_INFO_SCALE: |
| 158 | for (i = 0; i < ARRAY_SIZE(al3320a_scales); i++) { |
| 159 | if (val == al3320a_scales[i][0] && |
| 160 | val2 == al3320a_scales[i][1]) |
| 161 | return i2c_smbus_write_byte_data(data->client, |
| 162 | AL3320A_REG_CONFIG_RANGE, |
| 163 | i << AL3320A_GAIN_SHIFT); |
| 164 | } |
| 165 | break; |
| 166 | } |
| 167 | return -EINVAL; |
| 168 | } |
| 169 | |
| 170 | static const struct iio_info al3320a_info = { |
| 171 | .driver_module = THIS_MODULE, |
| 172 | .read_raw = al3320a_read_raw, |
| 173 | .write_raw = al3320a_write_raw, |
| 174 | .attrs = &al3320a_attribute_group, |
| 175 | }; |
| 176 | |
| 177 | static int al3320a_probe(struct i2c_client *client, |
| 178 | const struct i2c_device_id *id) |
| 179 | { |
| 180 | struct al3320a_data *data; |
| 181 | struct iio_dev *indio_dev; |
| 182 | int ret; |
| 183 | |
| 184 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| 185 | if (!indio_dev) |
| 186 | return -ENOMEM; |
| 187 | |
| 188 | data = iio_priv(indio_dev); |
| 189 | i2c_set_clientdata(client, indio_dev); |
| 190 | data->client = client; |
| 191 | |
| 192 | indio_dev->dev.parent = &client->dev; |
| 193 | indio_dev->info = &al3320a_info; |
| 194 | indio_dev->name = AL3320A_DRV_NAME; |
| 195 | indio_dev->channels = al3320a_channels; |
| 196 | indio_dev->num_channels = ARRAY_SIZE(al3320a_channels); |
| 197 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 198 | |
| 199 | ret = al3320a_init(data); |
| 200 | if (ret < 0) { |
| 201 | dev_err(&client->dev, "al3320a chip init failed\n"); |
| 202 | return ret; |
| 203 | } |
| 204 | return devm_iio_device_register(&client->dev, indio_dev); |
| 205 | } |
| 206 | |
| 207 | static int al3320a_remove(struct i2c_client *client) |
| 208 | { |
| 209 | return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG, |
| 210 | AL3320A_CONFIG_DISABLE); |
| 211 | } |
| 212 | |
| 213 | static const struct i2c_device_id al3320a_id[] = { |
| 214 | {"al3320a", 0}, |
| 215 | {} |
| 216 | }; |
| 217 | MODULE_DEVICE_TABLE(i2c, al3320a_id); |
| 218 | |
| 219 | static struct i2c_driver al3320a_driver = { |
| 220 | .driver = { |
| 221 | .name = AL3320A_DRV_NAME, |
| 222 | }, |
| 223 | .probe = al3320a_probe, |
| 224 | .remove = al3320a_remove, |
| 225 | .id_table = al3320a_id, |
| 226 | }; |
| 227 | |
| 228 | module_i2c_driver(al3320a_driver); |
| 229 | |
| 230 | MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>"); |
| 231 | MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver"); |
| 232 | MODULE_LICENSE("GPL v2"); |