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