1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ROHM 1780GLI Ambient Light Sensor Driver 4 * 5 * Copyright (C) 2016 Linaro Ltd. 6 * Author: Linus Walleij <linus.walleij@linaro.org> 7 * Loosely based on the previous BH1780 ALS misc driver 8 * Copyright (C) 2010 Texas Instruments 9 * Author: Hemanth V <hemanthv@ti.com> 10 */ 11 #include <linux/i2c.h> 12 #include <linux/slab.h> 13 #include <linux/platform_device.h> 14 #include <linux/delay.h> 15 #include <linux/module.h> 16 #include <linux/mod_devicetable.h> 17 #include <linux/pm_runtime.h> 18 #include <linux/iio/iio.h> 19 #include <linux/iio/sysfs.h> 20 #include <linux/bitops.h> 21 22 #define BH1780_CMD_BIT BIT(7) 23 #define BH1780_REG_CONTROL 0x00 24 #define BH1780_REG_PARTID 0x0A 25 #define BH1780_REG_MANFID 0x0B 26 #define BH1780_REG_DLOW 0x0C 27 #define BH1780_REG_DHIGH 0x0D 28 29 #define BH1780_REVMASK GENMASK(3,0) 30 #define BH1780_POWMASK GENMASK(1,0) 31 #define BH1780_POFF (0x0) 32 #define BH1780_PON (0x3) 33 34 /* power on settling time in ms */ 35 #define BH1780_PON_DELAY 2 36 /* max time before value available in ms */ 37 #define BH1780_INTERVAL 250 38 39 struct bh1780_data { 40 struct i2c_client *client; 41 }; 42 43 static int bh1780_write(struct bh1780_data *bh1780, u8 reg, u8 val) 44 { 45 int ret = i2c_smbus_write_byte_data(bh1780->client, 46 BH1780_CMD_BIT | reg, 47 val); 48 if (ret < 0) 49 dev_err(&bh1780->client->dev, 50 "i2c_smbus_write_byte_data failed error " 51 "%d, register %01x\n", 52 ret, reg); 53 return ret; 54 } 55 56 static int bh1780_read(struct bh1780_data *bh1780, u8 reg) 57 { 58 int ret = i2c_smbus_read_byte_data(bh1780->client, 59 BH1780_CMD_BIT | reg); 60 if (ret < 0) 61 dev_err(&bh1780->client->dev, 62 "i2c_smbus_read_byte_data failed error " 63 "%d, register %01x\n", 64 ret, reg); 65 return ret; 66 } 67 68 static int bh1780_read_word(struct bh1780_data *bh1780, u8 reg) 69 { 70 int ret = i2c_smbus_read_word_data(bh1780->client, 71 BH1780_CMD_BIT | reg); 72 if (ret < 0) 73 dev_err(&bh1780->client->dev, 74 "i2c_smbus_read_word_data failed error " 75 "%d, register %01x\n", 76 ret, reg); 77 return ret; 78 } 79 80 static int bh1780_debugfs_reg_access(struct iio_dev *indio_dev, 81 unsigned int reg, unsigned int writeval, 82 unsigned int *readval) 83 { 84 struct bh1780_data *bh1780 = iio_priv(indio_dev); 85 int ret; 86 87 if (!readval) 88 return bh1780_write(bh1780, (u8)reg, (u8)writeval); 89 90 ret = bh1780_read(bh1780, (u8)reg); 91 if (ret < 0) 92 return ret; 93 94 *readval = ret; 95 96 return 0; 97 } 98 99 static int bh1780_read_raw(struct iio_dev *indio_dev, 100 struct iio_chan_spec const *chan, 101 int *val, int *val2, long mask) 102 { 103 struct bh1780_data *bh1780 = iio_priv(indio_dev); 104 int value; 105 106 switch (mask) { 107 case IIO_CHAN_INFO_RAW: 108 switch (chan->type) { 109 case IIO_LIGHT: 110 pm_runtime_get_sync(&bh1780->client->dev); 111 value = bh1780_read_word(bh1780, BH1780_REG_DLOW); 112 if (value < 0) 113 return value; 114 pm_runtime_put_autosuspend(&bh1780->client->dev); 115 *val = value; 116 117 return IIO_VAL_INT; 118 default: 119 return -EINVAL; 120 } 121 case IIO_CHAN_INFO_INT_TIME: 122 *val = 0; 123 *val2 = BH1780_INTERVAL * 1000; 124 return IIO_VAL_INT_PLUS_MICRO; 125 default: 126 return -EINVAL; 127 } 128 } 129 130 static const struct iio_info bh1780_info = { 131 .read_raw = bh1780_read_raw, 132 .debugfs_reg_access = bh1780_debugfs_reg_access, 133 }; 134 135 static const struct iio_chan_spec bh1780_channels[] = { 136 { 137 .type = IIO_LIGHT, 138 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 139 BIT(IIO_CHAN_INFO_INT_TIME) 140 } 141 }; 142 143 static int bh1780_probe(struct i2c_client *client) 144 { 145 int ret; 146 struct bh1780_data *bh1780; 147 struct i2c_adapter *adapter = client->adapter; 148 struct iio_dev *indio_dev; 149 150 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 151 return -EIO; 152 153 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*bh1780)); 154 if (!indio_dev) 155 return -ENOMEM; 156 157 bh1780 = iio_priv(indio_dev); 158 bh1780->client = client; 159 i2c_set_clientdata(client, indio_dev); 160 161 /* Power up the device */ 162 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON); 163 if (ret < 0) 164 return ret; 165 msleep(BH1780_PON_DELAY); 166 pm_runtime_get_noresume(&client->dev); 167 pm_runtime_set_active(&client->dev); 168 pm_runtime_enable(&client->dev); 169 170 ret = bh1780_read(bh1780, BH1780_REG_PARTID); 171 if (ret < 0) 172 goto out_disable_pm; 173 dev_info(&client->dev, 174 "Ambient Light Sensor, Rev : %lu\n", 175 (ret & BH1780_REVMASK)); 176 177 /* 178 * As the device takes 250 ms to even come up with a fresh 179 * measurement after power-on, do not shut it down unnecessarily. 180 * Set autosuspend to a five seconds. 181 */ 182 pm_runtime_set_autosuspend_delay(&client->dev, 5000); 183 pm_runtime_use_autosuspend(&client->dev); 184 pm_runtime_put(&client->dev); 185 186 indio_dev->info = &bh1780_info; 187 indio_dev->name = "bh1780"; 188 indio_dev->channels = bh1780_channels; 189 indio_dev->num_channels = ARRAY_SIZE(bh1780_channels); 190 indio_dev->modes = INDIO_DIRECT_MODE; 191 192 ret = iio_device_register(indio_dev); 193 if (ret) 194 goto out_disable_pm; 195 return 0; 196 197 out_disable_pm: 198 pm_runtime_put_noidle(&client->dev); 199 pm_runtime_disable(&client->dev); 200 return ret; 201 } 202 203 static void bh1780_remove(struct i2c_client *client) 204 { 205 struct iio_dev *indio_dev = i2c_get_clientdata(client); 206 struct bh1780_data *bh1780 = iio_priv(indio_dev); 207 int ret; 208 209 iio_device_unregister(indio_dev); 210 pm_runtime_get_sync(&client->dev); 211 pm_runtime_put_noidle(&client->dev); 212 pm_runtime_disable(&client->dev); 213 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF); 214 if (ret < 0) 215 dev_err(&client->dev, "failed to power off (%pe)\n", 216 ERR_PTR(ret)); 217 } 218 219 static int bh1780_runtime_suspend(struct device *dev) 220 { 221 struct i2c_client *client = to_i2c_client(dev); 222 struct iio_dev *indio_dev = i2c_get_clientdata(client); 223 struct bh1780_data *bh1780 = iio_priv(indio_dev); 224 int ret; 225 226 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF); 227 if (ret < 0) { 228 dev_err(dev, "failed to runtime suspend\n"); 229 return ret; 230 } 231 232 return 0; 233 } 234 235 static int bh1780_runtime_resume(struct device *dev) 236 { 237 struct i2c_client *client = to_i2c_client(dev); 238 struct iio_dev *indio_dev = i2c_get_clientdata(client); 239 struct bh1780_data *bh1780 = iio_priv(indio_dev); 240 int ret; 241 242 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON); 243 if (ret < 0) { 244 dev_err(dev, "failed to runtime resume\n"); 245 return ret; 246 } 247 248 /* Wait for power on, then for a value to be available */ 249 msleep(BH1780_PON_DELAY + BH1780_INTERVAL); 250 251 return 0; 252 } 253 254 static DEFINE_RUNTIME_DEV_PM_OPS(bh1780_dev_pm_ops, bh1780_runtime_suspend, 255 bh1780_runtime_resume, NULL); 256 257 static const struct i2c_device_id bh1780_id[] = { 258 { "bh1780" }, 259 { } 260 }; 261 262 MODULE_DEVICE_TABLE(i2c, bh1780_id); 263 264 static const struct of_device_id of_bh1780_match[] = { 265 { .compatible = "rohm,bh1780gli", }, 266 { } 267 }; 268 MODULE_DEVICE_TABLE(of, of_bh1780_match); 269 270 static struct i2c_driver bh1780_driver = { 271 .probe = bh1780_probe, 272 .remove = bh1780_remove, 273 .id_table = bh1780_id, 274 .driver = { 275 .name = "bh1780", 276 .pm = pm_ptr(&bh1780_dev_pm_ops), 277 .of_match_table = of_bh1780_match, 278 }, 279 }; 280 281 module_i2c_driver(bh1780_driver); 282 283 MODULE_DESCRIPTION("ROHM BH1780GLI Ambient Light Sensor Driver"); 284 MODULE_LICENSE("GPL"); 285 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); 286