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1 | /* |
2 | * Copyright 2011 bct electronic GmbH | |
3 | * | |
4 | * Author: Peter Meerwald <p.meerwald@bct-electronic.com> | |
5 | * | |
6 | * Based on leds-pca955x.c | |
7 | * | |
8 | * This file is subject to the terms and conditions of version 2 of | |
9 | * the GNU General Public License. See the file COPYING in the main | |
10 | * directory of this archive for more details. | |
11 | * | |
12 | * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62) | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/module.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/string.h> | |
19 | #include <linux/ctype.h> | |
20 | #include <linux/leds.h> | |
21 | #include <linux/err.h> | |
22 | #include <linux/i2c.h> | |
23 | #include <linux/workqueue.h> | |
24 | #include <linux/slab.h> | |
25 | ||
26 | /* LED select registers determine the source that drives LED outputs */ | |
27 | #define PCA9633_LED_OFF 0x0 /* LED driver off */ | |
28 | #define PCA9633_LED_ON 0x1 /* LED driver on */ | |
29 | #define PCA9633_LED_PWM 0x2 /* Controlled through PWM */ | |
30 | #define PCA9633_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */ | |
31 | ||
32 | #define PCA9633_MODE1 0x00 | |
33 | #define PCA9633_MODE2 0x01 | |
34 | #define PCA9633_PWM_BASE 0x02 | |
35 | #define PCA9633_LEDOUT 0x08 | |
36 | ||
37 | static const struct i2c_device_id pca9633_id[] = { | |
38 | { "pca9633", 0 }, | |
39 | { } | |
40 | }; | |
41 | MODULE_DEVICE_TABLE(i2c, pca9633_id); | |
42 | ||
43 | struct pca9633_led { | |
44 | struct i2c_client *client; | |
45 | struct work_struct work; | |
46 | enum led_brightness brightness; | |
47 | struct led_classdev led_cdev; | |
48 | int led_num; /* 0 .. 3 potentially */ | |
49 | char name[32]; | |
50 | }; | |
51 | ||
52 | static void pca9633_led_work(struct work_struct *work) | |
53 | { | |
54 | struct pca9633_led *pca9633 = container_of(work, | |
55 | struct pca9633_led, work); | |
56 | u8 ledout = i2c_smbus_read_byte_data(pca9633->client, PCA9633_LEDOUT); | |
57 | int shift = 2 * pca9633->led_num; | |
58 | u8 mask = 0x3 << shift; | |
59 | ||
60 | switch (pca9633->brightness) { | |
61 | case LED_FULL: | |
62 | i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT, | |
63 | (ledout & ~mask) | (PCA9633_LED_ON << shift)); | |
64 | break; | |
65 | case LED_OFF: | |
66 | i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT, | |
67 | ledout & ~mask); | |
68 | break; | |
69 | default: | |
70 | i2c_smbus_write_byte_data(pca9633->client, | |
71 | PCA9633_PWM_BASE + pca9633->led_num, | |
72 | pca9633->brightness); | |
73 | i2c_smbus_write_byte_data(pca9633->client, PCA9633_LEDOUT, | |
74 | (ledout & ~mask) | (PCA9633_LED_PWM << shift)); | |
75 | break; | |
76 | } | |
77 | } | |
78 | ||
79 | static void pca9633_led_set(struct led_classdev *led_cdev, | |
80 | enum led_brightness value) | |
81 | { | |
82 | struct pca9633_led *pca9633; | |
83 | ||
84 | pca9633 = container_of(led_cdev, struct pca9633_led, led_cdev); | |
85 | ||
86 | pca9633->brightness = value; | |
87 | ||
88 | /* | |
89 | * Must use workqueue for the actual I/O since I2C operations | |
90 | * can sleep. | |
91 | */ | |
92 | schedule_work(&pca9633->work); | |
93 | } | |
94 | ||
95 | static int __devinit pca9633_probe(struct i2c_client *client, | |
96 | const struct i2c_device_id *id) | |
97 | { | |
98 | struct pca9633_led *pca9633; | |
99 | struct i2c_adapter *adapter; | |
100 | struct led_platform_data *pdata; | |
101 | int i, err; | |
102 | ||
103 | adapter = to_i2c_adapter(client->dev.parent); | |
104 | pdata = client->dev.platform_data; | |
105 | ||
106 | if (pdata) { | |
107 | if (pdata->num_leds <= 0 || pdata->num_leds > 4) { | |
108 | dev_err(&client->dev, "board info must claim at most 4 LEDs"); | |
109 | return -EINVAL; | |
110 | } | |
111 | } | |
112 | ||
113 | pca9633 = kcalloc(4, sizeof(*pca9633), GFP_KERNEL); | |
114 | if (!pca9633) | |
115 | return -ENOMEM; | |
116 | ||
117 | i2c_set_clientdata(client, pca9633); | |
118 | ||
119 | for (i = 0; i < 4; i++) { | |
120 | pca9633[i].client = client; | |
121 | pca9633[i].led_num = i; | |
122 | ||
123 | /* Platform data can specify LED names and default triggers */ | |
124 | if (pdata && i < pdata->num_leds) { | |
125 | if (pdata->leds[i].name) | |
126 | snprintf(pca9633[i].name, | |
127 | sizeof(pca9633[i].name), "pca9633:%s", | |
128 | pdata->leds[i].name); | |
129 | if (pdata->leds[i].default_trigger) | |
130 | pca9633[i].led_cdev.default_trigger = | |
131 | pdata->leds[i].default_trigger; | |
132 | } else { | |
133 | snprintf(pca9633[i].name, sizeof(pca9633[i].name), | |
134 | "pca9633:%d", i); | |
135 | } | |
136 | ||
137 | pca9633[i].led_cdev.name = pca9633[i].name; | |
138 | pca9633[i].led_cdev.brightness_set = pca9633_led_set; | |
139 | ||
140 | INIT_WORK(&pca9633[i].work, pca9633_led_work); | |
141 | ||
142 | err = led_classdev_register(&client->dev, &pca9633[i].led_cdev); | |
143 | if (err < 0) | |
144 | goto exit; | |
145 | } | |
146 | ||
147 | /* Disable LED all-call address and set normal mode */ | |
148 | i2c_smbus_write_byte_data(client, PCA9633_MODE1, 0x00); | |
149 | ||
150 | /* Turn off LEDs */ | |
151 | i2c_smbus_write_byte_data(client, PCA9633_LEDOUT, 0x00); | |
152 | ||
153 | return 0; | |
154 | ||
155 | exit: | |
156 | while (i--) { | |
157 | led_classdev_unregister(&pca9633[i].led_cdev); | |
158 | cancel_work_sync(&pca9633[i].work); | |
159 | } | |
160 | ||
161 | kfree(pca9633); | |
162 | ||
163 | return err; | |
164 | } | |
165 | ||
166 | static int __devexit pca9633_remove(struct i2c_client *client) | |
167 | { | |
168 | struct pca9633_led *pca9633 = i2c_get_clientdata(client); | |
169 | int i; | |
170 | ||
171 | for (i = 0; i < 4; i++) { | |
172 | led_classdev_unregister(&pca9633[i].led_cdev); | |
173 | cancel_work_sync(&pca9633[i].work); | |
174 | } | |
175 | ||
176 | kfree(pca9633); | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | static struct i2c_driver pca9633_driver = { | |
182 | .driver = { | |
183 | .name = "leds-pca9633", | |
184 | .owner = THIS_MODULE, | |
185 | }, | |
186 | .probe = pca9633_probe, | |
187 | .remove = __devexit_p(pca9633_remove), | |
188 | .id_table = pca9633_id, | |
189 | }; | |
190 | ||
191 | module_i2c_driver(pca9633_driver); | |
192 | ||
193 | MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>"); | |
194 | MODULE_DESCRIPTION("PCA9633 LED driver"); | |
195 | MODULE_LICENSE("GPL v2"); |