Root/drivers/misc/isl29003.c

1/*
2 * isl29003.c - Linux kernel module for
3 * Intersil ISL29003 ambient light sensor
4 *
5 * See file:Documentation/misc-devices/isl29003
6 *
7 * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
8 *
9 * Based on code written by
10 * Rodolfo Giometti <giometti@linux.it>
11 * Eurotech S.p.A. <info@eurotech.it>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28#include <linux/module.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/i2c.h>
32#include <linux/mutex.h>
33#include <linux/delay.h>
34
35#define ISL29003_DRV_NAME "isl29003"
36#define DRIVER_VERSION "1.0"
37
38#define ISL29003_REG_COMMAND 0x00
39#define ISL29003_ADC_ENABLED (1 << 7)
40#define ISL29003_ADC_PD (1 << 6)
41#define ISL29003_TIMING_INT (1 << 5)
42#define ISL29003_MODE_SHIFT (2)
43#define ISL29003_MODE_MASK (0x3 << ISL29003_MODE_SHIFT)
44#define ISL29003_RES_SHIFT (0)
45#define ISL29003_RES_MASK (0x3 << ISL29003_RES_SHIFT)
46
47#define ISL29003_REG_CONTROL 0x01
48#define ISL29003_INT_FLG (1 << 5)
49#define ISL29003_RANGE_SHIFT (2)
50#define ISL29003_RANGE_MASK (0x3 << ISL29003_RANGE_SHIFT)
51#define ISL29003_INT_PERSISTS_SHIFT (0)
52#define ISL29003_INT_PERSISTS_MASK (0xf << ISL29003_INT_PERSISTS_SHIFT)
53
54#define ISL29003_REG_IRQ_THRESH_HI 0x02
55#define ISL29003_REG_IRQ_THRESH_LO 0x03
56#define ISL29003_REG_LSB_SENSOR 0x04
57#define ISL29003_REG_MSB_SENSOR 0x05
58#define ISL29003_REG_LSB_TIMER 0x06
59#define ISL29003_REG_MSB_TIMER 0x07
60
61#define ISL29003_NUM_CACHABLE_REGS 4
62
63struct isl29003_data {
64    struct i2c_client *client;
65    struct mutex lock;
66    u8 reg_cache[ISL29003_NUM_CACHABLE_REGS];
67    u8 power_state_before_suspend;
68};
69
70static int gain_range[] = {
71    1000, 4000, 16000, 64000
72};
73
74/*
75 * register access helpers
76 */
77
78static int __isl29003_read_reg(struct i2c_client *client,
79                   u32 reg, u8 mask, u8 shift)
80{
81    struct isl29003_data *data = i2c_get_clientdata(client);
82    return (data->reg_cache[reg] & mask) >> shift;
83}
84
85static int __isl29003_write_reg(struct i2c_client *client,
86                u32 reg, u8 mask, u8 shift, u8 val)
87{
88    struct isl29003_data *data = i2c_get_clientdata(client);
89    int ret = 0;
90    u8 tmp;
91
92    if (reg >= ISL29003_NUM_CACHABLE_REGS)
93        return -EINVAL;
94
95    mutex_lock(&data->lock);
96
97    tmp = data->reg_cache[reg];
98    tmp &= ~mask;
99    tmp |= val << shift;
100
101    ret = i2c_smbus_write_byte_data(client, reg, tmp);
102    if (!ret)
103        data->reg_cache[reg] = tmp;
104
105    mutex_unlock(&data->lock);
106    return ret;
107}
108
109/*
110 * internally used functions
111 */
112
113/* range */
114static int isl29003_get_range(struct i2c_client *client)
115{
116    return __isl29003_read_reg(client, ISL29003_REG_CONTROL,
117        ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT);
118}
119
120static int isl29003_set_range(struct i2c_client *client, int range)
121{
122    return __isl29003_write_reg(client, ISL29003_REG_CONTROL,
123        ISL29003_RANGE_MASK, ISL29003_RANGE_SHIFT, range);
124}
125
126/* resolution */
127static int isl29003_get_resolution(struct i2c_client *client)
128{
129    return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
130        ISL29003_RES_MASK, ISL29003_RES_SHIFT);
131}
132
133static int isl29003_set_resolution(struct i2c_client *client, int res)
134{
135    return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
136        ISL29003_RES_MASK, ISL29003_RES_SHIFT, res);
137}
138
139/* mode */
140static int isl29003_get_mode(struct i2c_client *client)
141{
142    return __isl29003_read_reg(client, ISL29003_REG_COMMAND,
143        ISL29003_RES_MASK, ISL29003_RES_SHIFT);
144}
145
146static int isl29003_set_mode(struct i2c_client *client, int mode)
147{
148    return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
149        ISL29003_RES_MASK, ISL29003_RES_SHIFT, mode);
150}
151
152/* power_state */
153static int isl29003_set_power_state(struct i2c_client *client, int state)
154{
155    return __isl29003_write_reg(client, ISL29003_REG_COMMAND,
156                ISL29003_ADC_ENABLED | ISL29003_ADC_PD, 0,
157                state ? ISL29003_ADC_ENABLED : ISL29003_ADC_PD);
158}
159
160static int isl29003_get_power_state(struct i2c_client *client)
161{
162    struct isl29003_data *data = i2c_get_clientdata(client);
163    u8 cmdreg = data->reg_cache[ISL29003_REG_COMMAND];
164    return ~cmdreg & ISL29003_ADC_PD;
165}
166
167static int isl29003_get_adc_value(struct i2c_client *client)
168{
169    struct isl29003_data *data = i2c_get_clientdata(client);
170    int lsb, msb, range, bitdepth;
171
172    mutex_lock(&data->lock);
173    lsb = i2c_smbus_read_byte_data(client, ISL29003_REG_LSB_SENSOR);
174
175    if (lsb < 0) {
176        mutex_unlock(&data->lock);
177        return lsb;
178    }
179
180    msb = i2c_smbus_read_byte_data(client, ISL29003_REG_MSB_SENSOR);
181    mutex_unlock(&data->lock);
182
183    if (msb < 0)
184        return msb;
185
186    range = isl29003_get_range(client);
187    bitdepth = (4 - isl29003_get_resolution(client)) * 4;
188    return (((msb << 8) | lsb) * gain_range[range]) >> bitdepth;
189}
190
191/*
192 * sysfs layer
193 */
194
195/* range */
196static ssize_t isl29003_show_range(struct device *dev,
197                   struct device_attribute *attr, char *buf)
198{
199    struct i2c_client *client = to_i2c_client(dev);
200    return sprintf(buf, "%i\n", isl29003_get_range(client));
201}
202
203static ssize_t isl29003_store_range(struct device *dev,
204                    struct device_attribute *attr,
205                    const char *buf, size_t count)
206{
207    struct i2c_client *client = to_i2c_client(dev);
208    unsigned long val;
209    int ret;
210
211    if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3))
212        return -EINVAL;
213
214    ret = isl29003_set_range(client, val);
215    if (ret < 0)
216        return ret;
217
218    return count;
219}
220
221static DEVICE_ATTR(range, S_IWUSR | S_IRUGO,
222           isl29003_show_range, isl29003_store_range);
223
224
225/* resolution */
226static ssize_t isl29003_show_resolution(struct device *dev,
227                    struct device_attribute *attr,
228                    char *buf)
229{
230    struct i2c_client *client = to_i2c_client(dev);
231    return sprintf(buf, "%d\n", isl29003_get_resolution(client));
232}
233
234static ssize_t isl29003_store_resolution(struct device *dev,
235                     struct device_attribute *attr,
236                     const char *buf, size_t count)
237{
238    struct i2c_client *client = to_i2c_client(dev);
239    unsigned long val;
240    int ret;
241
242    if ((strict_strtoul(buf, 10, &val) < 0) || (val > 3))
243        return -EINVAL;
244
245    ret = isl29003_set_resolution(client, val);
246    if (ret < 0)
247        return ret;
248
249    return count;
250}
251
252static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO,
253           isl29003_show_resolution, isl29003_store_resolution);
254
255/* mode */
256static ssize_t isl29003_show_mode(struct device *dev,
257                  struct device_attribute *attr, char *buf)
258{
259    struct i2c_client *client = to_i2c_client(dev);
260    return sprintf(buf, "%d\n", isl29003_get_mode(client));
261}
262
263static ssize_t isl29003_store_mode(struct device *dev,
264        struct device_attribute *attr, const char *buf, size_t count)
265{
266    struct i2c_client *client = to_i2c_client(dev);
267    unsigned long val;
268    int ret;
269
270    if ((strict_strtoul(buf, 10, &val) < 0) || (val > 2))
271        return -EINVAL;
272
273    ret = isl29003_set_mode(client, val);
274    if (ret < 0)
275        return ret;
276
277    return count;
278}
279
280static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
281           isl29003_show_mode, isl29003_store_mode);
282
283
284/* power state */
285static ssize_t isl29003_show_power_state(struct device *dev,
286                     struct device_attribute *attr,
287                     char *buf)
288{
289    struct i2c_client *client = to_i2c_client(dev);
290    return sprintf(buf, "%d\n", isl29003_get_power_state(client));
291}
292
293static ssize_t isl29003_store_power_state(struct device *dev,
294                      struct device_attribute *attr,
295                      const char *buf, size_t count)
296{
297    struct i2c_client *client = to_i2c_client(dev);
298    unsigned long val;
299    int ret;
300
301    if ((strict_strtoul(buf, 10, &val) < 0) || (val > 1))
302        return -EINVAL;
303
304    ret = isl29003_set_power_state(client, val);
305    return ret ? ret : count;
306}
307
308static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
309           isl29003_show_power_state, isl29003_store_power_state);
310
311
312/* lux */
313static ssize_t isl29003_show_lux(struct device *dev,
314                 struct device_attribute *attr, char *buf)
315{
316    struct i2c_client *client = to_i2c_client(dev);
317
318    /* No LUX data if not operational */
319    if (!isl29003_get_power_state(client))
320        return -EBUSY;
321
322    return sprintf(buf, "%d\n", isl29003_get_adc_value(client));
323}
324
325static DEVICE_ATTR(lux, S_IRUGO, isl29003_show_lux, NULL);
326
327static struct attribute *isl29003_attributes[] = {
328    &dev_attr_range.attr,
329    &dev_attr_resolution.attr,
330    &dev_attr_mode.attr,
331    &dev_attr_power_state.attr,
332    &dev_attr_lux.attr,
333    NULL
334};
335
336static const struct attribute_group isl29003_attr_group = {
337    .attrs = isl29003_attributes,
338};
339
340static int isl29003_init_client(struct i2c_client *client)
341{
342    struct isl29003_data *data = i2c_get_clientdata(client);
343    int i;
344
345    /* read all the registers once to fill the cache.
346     * if one of the reads fails, we consider the init failed */
347    for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
348        int v = i2c_smbus_read_byte_data(client, i);
349        if (v < 0)
350            return -ENODEV;
351
352        data->reg_cache[i] = v;
353    }
354
355    /* set defaults */
356    isl29003_set_range(client, 0);
357    isl29003_set_resolution(client, 0);
358    isl29003_set_mode(client, 0);
359    isl29003_set_power_state(client, 0);
360
361    return 0;
362}
363
364/*
365 * I2C layer
366 */
367
368static int __devinit isl29003_probe(struct i2c_client *client,
369                    const struct i2c_device_id *id)
370{
371    struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
372    struct isl29003_data *data;
373    int err = 0;
374
375    if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
376        return -EIO;
377
378    data = kzalloc(sizeof(struct isl29003_data), GFP_KERNEL);
379    if (!data)
380        return -ENOMEM;
381
382    data->client = client;
383    i2c_set_clientdata(client, data);
384    mutex_init(&data->lock);
385
386    /* initialize the ISL29003 chip */
387    err = isl29003_init_client(client);
388    if (err)
389        goto exit_kfree;
390
391    /* register sysfs hooks */
392    err = sysfs_create_group(&client->dev.kobj, &isl29003_attr_group);
393    if (err)
394        goto exit_kfree;
395
396    dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
397    return 0;
398
399exit_kfree:
400    kfree(data);
401    return err;
402}
403
404static int __devexit isl29003_remove(struct i2c_client *client)
405{
406    sysfs_remove_group(&client->dev.kobj, &isl29003_attr_group);
407    isl29003_set_power_state(client, 0);
408    kfree(i2c_get_clientdata(client));
409    return 0;
410}
411
412#ifdef CONFIG_PM
413static int isl29003_suspend(struct i2c_client *client, pm_message_t mesg)
414{
415    struct isl29003_data *data = i2c_get_clientdata(client);
416
417    data->power_state_before_suspend = isl29003_get_power_state(client);
418    return isl29003_set_power_state(client, 0);
419}
420
421static int isl29003_resume(struct i2c_client *client)
422{
423    int i;
424    struct isl29003_data *data = i2c_get_clientdata(client);
425
426    /* restore registers from cache */
427    for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
428        if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
429            return -EIO;
430
431    return isl29003_set_power_state(client,
432        data->power_state_before_suspend);
433}
434
435#else
436#define isl29003_suspend NULL
437#define isl29003_resume NULL
438#endif /* CONFIG_PM */
439
440static const struct i2c_device_id isl29003_id[] = {
441    { "isl29003", 0 },
442    {}
443};
444MODULE_DEVICE_TABLE(i2c, isl29003_id);
445
446static struct i2c_driver isl29003_driver = {
447    .driver = {
448        .name = ISL29003_DRV_NAME,
449        .owner = THIS_MODULE,
450    },
451    .suspend = isl29003_suspend,
452    .resume = isl29003_resume,
453    .probe = isl29003_probe,
454    .remove = __devexit_p(isl29003_remove),
455    .id_table = isl29003_id,
456};
457
458module_i2c_driver(isl29003_driver);
459
460MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
461MODULE_DESCRIPTION("ISL29003 ambient light sensor driver");
462MODULE_LICENSE("GPL v2");
463MODULE_VERSION(DRIVER_VERSION);
464

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9



interactive