aboutsummaryrefslogtreecommitdiff
path: root/drivers/leds/leds-turris-omnia.c
blob: 7b2f4d0ae3fe90bc69efc57bec01e56196b6d3c3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
// SPDX-License-Identifier: GPL-2.0
/*
 * CZ.NIC's Turris Omnia LEDs driver
 *
 * 2020 by Marek Behun <marek.behun@nic.cz>
 */

#include <linux/i2c.h>
#include <linux/led-class-multicolor.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include "leds.h"

#define OMNIA_BOARD_LEDS	12
#define OMNIA_LED_NUM_CHANNELS	3

#define CMD_LED_MODE		3
#define CMD_LED_MODE_LED(l)	((l) & 0x0f)
#define CMD_LED_MODE_USER	0x10

#define CMD_LED_STATE		4
#define CMD_LED_STATE_LED(l)	((l) & 0x0f)
#define CMD_LED_STATE_ON	0x10

#define CMD_LED_COLOR		5
#define CMD_LED_SET_BRIGHTNESS	7
#define CMD_LED_GET_BRIGHTNESS	8

struct omnia_led {
	struct led_classdev_mc mc_cdev;
	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
	int reg;
};

#define to_omnia_led(l)		container_of(l, struct omnia_led, mc_cdev)

struct omnia_leds {
	struct i2c_client *client;
	struct mutex lock;
	struct omnia_led leds[];
};

static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
					     enum led_brightness brightness)
{
	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
	struct omnia_led *led = to_omnia_led(mc_cdev);
	u8 buf[5], state;
	int ret;

	mutex_lock(&leds->lock);

	led_mc_calc_color_components(&led->mc_cdev, brightness);

	buf[0] = CMD_LED_COLOR;
	buf[1] = led->reg;
	buf[2] = mc_cdev->subled_info[0].brightness;
	buf[3] = mc_cdev->subled_info[1].brightness;
	buf[4] = mc_cdev->subled_info[2].brightness;

	state = CMD_LED_STATE_LED(led->reg);
	if (buf[2] || buf[3] || buf[4])
		state |= CMD_LED_STATE_ON;

	ret = i2c_smbus_write_byte_data(leds->client, CMD_LED_STATE, state);
	if (ret >= 0 && (state & CMD_LED_STATE_ON))
		ret = i2c_master_send(leds->client, buf, 5);

	mutex_unlock(&leds->lock);

	return ret;
}

static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
			      struct device_node *np)
{
	struct led_init_data init_data = {};
	struct device *dev = &client->dev;
	struct led_classdev *cdev;
	int ret, color;

	ret = of_property_read_u32(np, "reg", &led->reg);
	if (ret || led->reg >= OMNIA_BOARD_LEDS) {
		dev_warn(dev,
			 "Node %pOF: must contain 'reg' property with values between 0 and %i\n",
			 np, OMNIA_BOARD_LEDS - 1);
		return 0;
	}

	ret = of_property_read_u32(np, "color", &color);
	if (ret || color != LED_COLOR_ID_RGB) {
		dev_warn(dev,
			 "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
			 np);
		return 0;
	}

	led->subled_info[0].color_index = LED_COLOR_ID_RED;
	led->subled_info[0].channel = 0;
	led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
	led->subled_info[1].channel = 1;
	led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
	led->subled_info[2].channel = 2;

	led->mc_cdev.subled_info = led->subled_info;
	led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;

	init_data.fwnode = &np->fwnode;

	cdev = &led->mc_cdev.led_cdev;
	cdev->max_brightness = 255;
	cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;

	/* put the LED into software mode */
	ret = i2c_smbus_write_byte_data(client, CMD_LED_MODE,
					CMD_LED_MODE_LED(led->reg) |
					CMD_LED_MODE_USER);
	if (ret < 0) {
		dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
			ret);
		return ret;
	}

	/* disable the LED */
	ret = i2c_smbus_write_byte_data(client, CMD_LED_STATE,
					CMD_LED_STATE_LED(led->reg));
	if (ret < 0) {
		dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
		return ret;
	}

	ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
							&init_data);
	if (ret < 0) {
		dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
		return ret;
	}

	return 1;
}

/*
 * On the front panel of the Turris Omnia router there is also a button which
 * can be used to control the intensity of all the LEDs at once, so that if they
 * are too bright, user can dim them.
 * The microcontroller cycles between 8 levels of this global brightness (from
 * 100% to 0%), but this setting can have any integer value between 0 and 100.
 * It is therefore convenient to be able to change this setting from software.
 * We expose this setting via a sysfs attribute file called "brightness". This
 * file lives in the device directory of the LED controller, not an individual
 * LED, so it should not confuse users.
 */
static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
			       char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct omnia_leds *leds = i2c_get_clientdata(client);
	int ret;

	mutex_lock(&leds->lock);
	ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS);
	mutex_unlock(&leds->lock);

	if (ret < 0)
		return ret;

	return sprintf(buf, "%d\n", ret);
}

static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
				const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct omnia_leds *leds = i2c_get_clientdata(client);
	unsigned long brightness;
	int ret;

	if (kstrtoul(buf, 10, &brightness))
		return -EINVAL;

	if (brightness > 100)
		return -EINVAL;

	mutex_lock(&leds->lock);
	ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS,
					(u8)brightness);
	mutex_unlock(&leds->lock);

	if (ret < 0)
		return ret;

	return count;
}
static DEVICE_ATTR_RW(brightness);

static struct attribute *omnia_led_controller_attrs[] = {
	&dev_attr_brightness.attr,
	NULL,
};
ATTRIBUTE_GROUPS(omnia_led_controller);

static int omnia_leds_probe(struct i2c_client *client,
			    const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct device_node *np = dev_of_node(dev), *child;
	struct omnia_leds *leds;
	struct omnia_led *led;
	int ret, count;

	count = of_get_available_child_count(np);
	if (!count) {
		dev_err(dev, "LEDs are not defined in device tree!\n");
		return -ENODEV;
	} else if (count > OMNIA_BOARD_LEDS) {
		dev_err(dev, "Too many LEDs defined in device tree!\n");
		return -EINVAL;
	}

	leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
	if (!leds)
		return -ENOMEM;

	leds->client = client;
	i2c_set_clientdata(client, leds);

	mutex_init(&leds->lock);

	led = &leds->leds[0];
	for_each_available_child_of_node(np, child) {
		ret = omnia_led_register(client, led, child);
		if (ret < 0) {
			of_node_put(child);
			return ret;
		}

		led += ret;
	}

	if (devm_device_add_groups(dev, omnia_led_controller_groups))
		dev_warn(dev, "Could not add attribute group!\n");

	return 0;
}

static int omnia_leds_remove(struct i2c_client *client)
{
	u8 buf[5];

	/* put all LEDs into default (HW triggered) mode */
	i2c_smbus_write_byte_data(client, CMD_LED_MODE,
				  CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));

	/* set all LEDs color to [255, 255, 255] */
	buf[0] = CMD_LED_COLOR;
	buf[1] = OMNIA_BOARD_LEDS;
	buf[2] = 255;
	buf[3] = 255;
	buf[4] = 255;

	i2c_master_send(client, buf, 5);

	return 0;
}

static const struct of_device_id of_omnia_leds_match[] = {
	{ .compatible = "cznic,turris-omnia-leds", },
	{},
};

static const struct i2c_device_id omnia_id[] = {
	{ "omnia", 0 },
	{ }
};

static struct i2c_driver omnia_leds_driver = {
	.probe		= omnia_leds_probe,
	.remove		= omnia_leds_remove,
	.id_table	= omnia_id,
	.driver		= {
		.name	= "leds-turris-omnia",
		.of_match_table = of_omnia_leds_match,
	},
};

module_i2c_driver(omnia_leds_driver);

MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs");
MODULE_LICENSE("GPL v2");