This source file includes following definitions.
- gpio_trig_irq
- gpio_trig_brightness_show
- gpio_trig_brightness_store
- gpio_trig_inverted_show
- gpio_trig_inverted_store
- gpio_trig_gpio_show
- gpio_trig_gpio_store
- gpio_trig_activate
- gpio_trig_deactivate
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8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/gpio.h>
12 #include <linux/interrupt.h>
13 #include <linux/leds.h>
14 #include <linux/slab.h>
15 #include "../leds.h"
16
17 struct gpio_trig_data {
18 struct led_classdev *led;
19
20 unsigned desired_brightness;
21 unsigned inverted;
22 unsigned gpio;
23 };
24
25 static irqreturn_t gpio_trig_irq(int irq, void *_led)
26 {
27 struct led_classdev *led = _led;
28 struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
29 int tmp;
30
31 tmp = gpio_get_value_cansleep(gpio_data->gpio);
32 if (gpio_data->inverted)
33 tmp = !tmp;
34
35 if (tmp) {
36 if (gpio_data->desired_brightness)
37 led_set_brightness_nosleep(gpio_data->led,
38 gpio_data->desired_brightness);
39 else
40 led_set_brightness_nosleep(gpio_data->led, LED_FULL);
41 } else {
42 led_set_brightness_nosleep(gpio_data->led, LED_OFF);
43 }
44
45 return IRQ_HANDLED;
46 }
47
48 static ssize_t gpio_trig_brightness_show(struct device *dev,
49 struct device_attribute *attr, char *buf)
50 {
51 struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
52
53 return sprintf(buf, "%u\n", gpio_data->desired_brightness);
54 }
55
56 static ssize_t gpio_trig_brightness_store(struct device *dev,
57 struct device_attribute *attr, const char *buf, size_t n)
58 {
59 struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
60 unsigned desired_brightness;
61 int ret;
62
63 ret = sscanf(buf, "%u", &desired_brightness);
64 if (ret < 1 || desired_brightness > 255) {
65 dev_err(dev, "invalid value\n");
66 return -EINVAL;
67 }
68
69 gpio_data->desired_brightness = desired_brightness;
70
71 return n;
72 }
73 static DEVICE_ATTR(desired_brightness, 0644, gpio_trig_brightness_show,
74 gpio_trig_brightness_store);
75
76 static ssize_t gpio_trig_inverted_show(struct device *dev,
77 struct device_attribute *attr, char *buf)
78 {
79 struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
80
81 return sprintf(buf, "%u\n", gpio_data->inverted);
82 }
83
84 static ssize_t gpio_trig_inverted_store(struct device *dev,
85 struct device_attribute *attr, const char *buf, size_t n)
86 {
87 struct led_classdev *led = led_trigger_get_led(dev);
88 struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
89 unsigned long inverted;
90 int ret;
91
92 ret = kstrtoul(buf, 10, &inverted);
93 if (ret < 0)
94 return ret;
95
96 if (inverted > 1)
97 return -EINVAL;
98
99 gpio_data->inverted = inverted;
100
101
102 gpio_trig_irq(0, led);
103
104 return n;
105 }
106 static DEVICE_ATTR(inverted, 0644, gpio_trig_inverted_show,
107 gpio_trig_inverted_store);
108
109 static ssize_t gpio_trig_gpio_show(struct device *dev,
110 struct device_attribute *attr, char *buf)
111 {
112 struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
113
114 return sprintf(buf, "%u\n", gpio_data->gpio);
115 }
116
117 static ssize_t gpio_trig_gpio_store(struct device *dev,
118 struct device_attribute *attr, const char *buf, size_t n)
119 {
120 struct led_classdev *led = led_trigger_get_led(dev);
121 struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
122 unsigned gpio;
123 int ret;
124
125 ret = sscanf(buf, "%u", &gpio);
126 if (ret < 1) {
127 dev_err(dev, "couldn't read gpio number\n");
128 return -EINVAL;
129 }
130
131 if (gpio_data->gpio == gpio)
132 return n;
133
134 if (!gpio_is_valid(gpio)) {
135 if (gpio_is_valid(gpio_data->gpio))
136 free_irq(gpio_to_irq(gpio_data->gpio), led);
137 gpio_data->gpio = gpio;
138 return n;
139 }
140
141 ret = request_threaded_irq(gpio_to_irq(gpio), NULL, gpio_trig_irq,
142 IRQF_ONESHOT | IRQF_SHARED | IRQF_TRIGGER_RISING
143 | IRQF_TRIGGER_FALLING, "ledtrig-gpio", led);
144 if (ret) {
145 dev_err(dev, "request_irq failed with error %d\n", ret);
146 } else {
147 if (gpio_is_valid(gpio_data->gpio))
148 free_irq(gpio_to_irq(gpio_data->gpio), led);
149 gpio_data->gpio = gpio;
150
151 gpio_trig_irq(0, led);
152 }
153
154 return ret ? ret : n;
155 }
156 static DEVICE_ATTR(gpio, 0644, gpio_trig_gpio_show, gpio_trig_gpio_store);
157
158 static struct attribute *gpio_trig_attrs[] = {
159 &dev_attr_desired_brightness.attr,
160 &dev_attr_inverted.attr,
161 &dev_attr_gpio.attr,
162 NULL
163 };
164 ATTRIBUTE_GROUPS(gpio_trig);
165
166 static int gpio_trig_activate(struct led_classdev *led)
167 {
168 struct gpio_trig_data *gpio_data;
169
170 gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
171 if (!gpio_data)
172 return -ENOMEM;
173
174 gpio_data->led = led;
175 gpio_data->gpio = -ENOENT;
176
177 led_set_trigger_data(led, gpio_data);
178
179 return 0;
180 }
181
182 static void gpio_trig_deactivate(struct led_classdev *led)
183 {
184 struct gpio_trig_data *gpio_data = led_get_trigger_data(led);
185
186 if (gpio_is_valid(gpio_data->gpio))
187 free_irq(gpio_to_irq(gpio_data->gpio), led);
188 kfree(gpio_data);
189 }
190
191 static struct led_trigger gpio_led_trigger = {
192 .name = "gpio",
193 .activate = gpio_trig_activate,
194 .deactivate = gpio_trig_deactivate,
195 .groups = gpio_trig_groups,
196 };
197 module_led_trigger(gpio_led_trigger);
198
199 MODULE_AUTHOR("Felipe Balbi <me@felipebalbi.com>");
200 MODULE_DESCRIPTION("GPIO LED trigger");
201 MODULE_LICENSE("GPL v2");