1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * apds9802als.c - apds9802 ALS Driver
4 *
5 * Copyright (C) 2009 Intel Corp
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10 */
11
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/i2c.h>
15 #include <linux/err.h>
16 #include <linux/delay.h>
17 #include <linux/mutex.h>
18 #include <linux/sysfs.h>
19 #include <linux/pm_runtime.h>
20
21 #define ALS_MIN_RANGE_VAL 1
22 #define ALS_MAX_RANGE_VAL 2
23 #define POWER_STA_ENABLE 1
24 #define POWER_STA_DISABLE 0
25
26 #define DRIVER_NAME "apds9802als"
27
28 struct als_data {
29 struct mutex mutex;
30 };
31
als_sensing_range_show(struct device * dev,struct device_attribute * attr,char * buf)32 static ssize_t als_sensing_range_show(struct device *dev,
33 struct device_attribute *attr, char *buf)
34 {
35 struct i2c_client *client = to_i2c_client(dev);
36 int val;
37
38 val = i2c_smbus_read_byte_data(client, 0x81);
39 if (val < 0)
40 return val;
41 if (val & 1)
42 return sprintf(buf, "4095\n");
43 else
44 return sprintf(buf, "65535\n");
45 }
46
als_wait_for_data_ready(struct device * dev)47 static int als_wait_for_data_ready(struct device *dev)
48 {
49 struct i2c_client *client = to_i2c_client(dev);
50 int ret;
51 int retry = 10;
52
53 do {
54 msleep(30);
55 ret = i2c_smbus_read_byte_data(client, 0x86);
56 } while (!(ret & 0x80) && retry--);
57
58 if (retry < 0) {
59 dev_warn(dev, "timeout waiting for data ready\n");
60 return -ETIMEDOUT;
61 }
62
63 return 0;
64 }
65
als_lux0_input_data_show(struct device * dev,struct device_attribute * attr,char * buf)66 static ssize_t als_lux0_input_data_show(struct device *dev,
67 struct device_attribute *attr, char *buf)
68 {
69 struct i2c_client *client = to_i2c_client(dev);
70 struct als_data *data = i2c_get_clientdata(client);
71 int ret_val;
72 int temp;
73
74 /* Protect against parallel reads */
75 pm_runtime_get_sync(dev);
76 mutex_lock(&data->mutex);
77
78 /* clear EOC interrupt status */
79 i2c_smbus_write_byte(client, 0x40);
80 /* start measurement */
81 temp = i2c_smbus_read_byte_data(client, 0x81);
82 i2c_smbus_write_byte_data(client, 0x81, temp | 0x08);
83
84 ret_val = als_wait_for_data_ready(dev);
85 if (ret_val < 0)
86 goto failed;
87
88 temp = i2c_smbus_read_byte_data(client, 0x8C); /* LSB data */
89 if (temp < 0) {
90 ret_val = temp;
91 goto failed;
92 }
93 ret_val = i2c_smbus_read_byte_data(client, 0x8D); /* MSB data */
94 if (ret_val < 0)
95 goto failed;
96
97 mutex_unlock(&data->mutex);
98 pm_runtime_put_sync(dev);
99
100 temp = (ret_val << 8) | temp;
101 return sprintf(buf, "%d\n", temp);
102 failed:
103 mutex_unlock(&data->mutex);
104 pm_runtime_put_sync(dev);
105 return ret_val;
106 }
107
als_sensing_range_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)108 static ssize_t als_sensing_range_store(struct device *dev,
109 struct device_attribute *attr, const char *buf, size_t count)
110 {
111 struct i2c_client *client = to_i2c_client(dev);
112 struct als_data *data = i2c_get_clientdata(client);
113 int ret_val;
114 unsigned long val;
115
116 ret_val = kstrtoul(buf, 10, &val);
117 if (ret_val)
118 return ret_val;
119
120 if (val < 4096)
121 val = 1;
122 else if (val < 65536)
123 val = 2;
124 else
125 return -ERANGE;
126
127 pm_runtime_get_sync(dev);
128
129 /* Make sure nobody else reads/modifies/writes 0x81 while we
130 are active */
131 mutex_lock(&data->mutex);
132
133 ret_val = i2c_smbus_read_byte_data(client, 0x81);
134 if (ret_val < 0)
135 goto fail;
136
137 /* Reset the bits before setting them */
138 ret_val = ret_val & 0xFA;
139
140 if (val == 1) /* Setting detection range up to 4k LUX */
141 ret_val = (ret_val | 0x01);
142 else /* Setting detection range up to 64k LUX*/
143 ret_val = (ret_val | 0x00);
144
145 ret_val = i2c_smbus_write_byte_data(client, 0x81, ret_val);
146
147 if (ret_val >= 0) {
148 /* All OK */
149 mutex_unlock(&data->mutex);
150 pm_runtime_put_sync(dev);
151 return count;
152 }
153 fail:
154 mutex_unlock(&data->mutex);
155 pm_runtime_put_sync(dev);
156 return ret_val;
157 }
158
als_set_power_state(struct i2c_client * client,bool on_off)159 static int als_set_power_state(struct i2c_client *client, bool on_off)
160 {
161 int ret_val;
162 struct als_data *data = i2c_get_clientdata(client);
163
164 mutex_lock(&data->mutex);
165 ret_val = i2c_smbus_read_byte_data(client, 0x80);
166 if (ret_val < 0)
167 goto fail;
168 if (on_off)
169 ret_val = ret_val | 0x01;
170 else
171 ret_val = ret_val & 0xFE;
172 ret_val = i2c_smbus_write_byte_data(client, 0x80, ret_val);
173 fail:
174 mutex_unlock(&data->mutex);
175 return ret_val;
176 }
177
178 static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
179 als_sensing_range_show, als_sensing_range_store);
180 static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux0_input_data_show, NULL);
181
182 static struct attribute *mid_att_als[] = {
183 &dev_attr_lux0_sensor_range.attr,
184 &dev_attr_lux0_input.attr,
185 NULL
186 };
187
188 static const struct attribute_group m_als_gr = {
189 .name = "apds9802als",
190 .attrs = mid_att_als
191 };
192
als_set_default_config(struct i2c_client * client)193 static int als_set_default_config(struct i2c_client *client)
194 {
195 int ret_val;
196 /* Write the command and then switch on */
197 ret_val = i2c_smbus_write_byte_data(client, 0x80, 0x01);
198 if (ret_val < 0) {
199 dev_err(&client->dev, "failed default switch on write\n");
200 return ret_val;
201 }
202 /* detection range: 1~64K Lux, maunal measurement */
203 ret_val = i2c_smbus_write_byte_data(client, 0x81, 0x08);
204 if (ret_val < 0)
205 dev_err(&client->dev, "failed default LUX on write\n");
206
207 /* We always get 0 for the 1st measurement after system power on,
208 * so make sure it is finished before user asks for data.
209 */
210 als_wait_for_data_ready(&client->dev);
211
212 return ret_val;
213 }
214
apds9802als_probe(struct i2c_client * client,const struct i2c_device_id * id)215 static int apds9802als_probe(struct i2c_client *client,
216 const struct i2c_device_id *id)
217 {
218 int res;
219 struct als_data *data;
220
221 data = kzalloc(sizeof(struct als_data), GFP_KERNEL);
222 if (data == NULL) {
223 dev_err(&client->dev, "Memory allocation failed\n");
224 return -ENOMEM;
225 }
226 i2c_set_clientdata(client, data);
227 res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
228 if (res) {
229 dev_err(&client->dev, "device create file failed\n");
230 goto als_error1;
231 }
232 dev_info(&client->dev, "ALS chip found\n");
233 als_set_default_config(client);
234 mutex_init(&data->mutex);
235
236 pm_runtime_set_active(&client->dev);
237 pm_runtime_enable(&client->dev);
238
239 return res;
240 als_error1:
241 kfree(data);
242 return res;
243 }
244
apds9802als_remove(struct i2c_client * client)245 static int apds9802als_remove(struct i2c_client *client)
246 {
247 struct als_data *data = i2c_get_clientdata(client);
248
249 pm_runtime_get_sync(&client->dev);
250
251 als_set_power_state(client, false);
252 sysfs_remove_group(&client->dev.kobj, &m_als_gr);
253
254 pm_runtime_disable(&client->dev);
255 pm_runtime_set_suspended(&client->dev);
256 pm_runtime_put_noidle(&client->dev);
257
258 kfree(data);
259 return 0;
260 }
261
262 #ifdef CONFIG_PM
263
apds9802als_suspend(struct device * dev)264 static int apds9802als_suspend(struct device *dev)
265 {
266 struct i2c_client *client = to_i2c_client(dev);
267
268 als_set_power_state(client, false);
269 return 0;
270 }
271
apds9802als_resume(struct device * dev)272 static int apds9802als_resume(struct device *dev)
273 {
274 struct i2c_client *client = to_i2c_client(dev);
275
276 als_set_power_state(client, true);
277 return 0;
278 }
279
280 static UNIVERSAL_DEV_PM_OPS(apds9802als_pm_ops, apds9802als_suspend,
281 apds9802als_resume, NULL);
282
283 #define APDS9802ALS_PM_OPS (&apds9802als_pm_ops)
284
285 #else /* CONFIG_PM */
286 #define APDS9802ALS_PM_OPS NULL
287 #endif /* CONFIG_PM */
288
289 static const struct i2c_device_id apds9802als_id[] = {
290 { DRIVER_NAME, 0 },
291 { }
292 };
293
294 MODULE_DEVICE_TABLE(i2c, apds9802als_id);
295
296 static struct i2c_driver apds9802als_driver = {
297 .driver = {
298 .name = DRIVER_NAME,
299 .pm = APDS9802ALS_PM_OPS,
300 },
301 .probe = apds9802als_probe,
302 .remove = apds9802als_remove,
303 .id_table = apds9802als_id,
304 };
305
306 module_i2c_driver(apds9802als_driver);
307
308 MODULE_AUTHOR("Anantha Narayanan <Anantha.Narayanan@intel.com");
309 MODULE_DESCRIPTION("Avago apds9802als ALS Driver");
310 MODULE_LICENSE("GPL v2");
311