1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * CZ.NIC's Turris Omnia LEDs driver
4 *
5 * 2020 by Marek Behun <marek.behun@nic.cz>
6 */
7
8 #include <linux/i2c.h>
9 #include <linux/led-class-multicolor.h>
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/of.h>
13 #include "leds.h"
14
15 #define OMNIA_BOARD_LEDS 12
16 #define OMNIA_LED_NUM_CHANNELS 3
17
18 #define CMD_LED_MODE 3
19 #define CMD_LED_MODE_LED(l) ((l) & 0x0f)
20 #define CMD_LED_MODE_USER 0x10
21
22 #define CMD_LED_STATE 4
23 #define CMD_LED_STATE_LED(l) ((l) & 0x0f)
24 #define CMD_LED_STATE_ON 0x10
25
26 #define CMD_LED_COLOR 5
27 #define CMD_LED_SET_BRIGHTNESS 7
28 #define CMD_LED_GET_BRIGHTNESS 8
29
30 #define OMNIA_CMD 0
31
32 #define OMNIA_CMD_LED_COLOR_LED 1
33 #define OMNIA_CMD_LED_COLOR_R 2
34 #define OMNIA_CMD_LED_COLOR_G 3
35 #define OMNIA_CMD_LED_COLOR_B 4
36 #define OMNIA_CMD_LED_COLOR_LEN 5
37
38 struct omnia_led {
39 struct led_classdev_mc mc_cdev;
40 struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
41 int reg;
42 };
43
44 #define to_omnia_led(l) container_of(l, struct omnia_led, mc_cdev)
45
46 struct omnia_leds {
47 struct i2c_client *client;
48 struct mutex lock;
49 struct omnia_led leds[];
50 };
51
omnia_led_brightness_set_blocking(struct led_classdev * cdev,enum led_brightness brightness)52 static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
53 enum led_brightness brightness)
54 {
55 struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
56 struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
57 struct omnia_led *led = to_omnia_led(mc_cdev);
58 u8 buf[OMNIA_CMD_LED_COLOR_LEN], state;
59 int ret;
60
61 mutex_lock(&leds->lock);
62
63 led_mc_calc_color_components(&led->mc_cdev, brightness);
64
65 buf[OMNIA_CMD] = CMD_LED_COLOR;
66 buf[OMNIA_CMD_LED_COLOR_LED] = led->reg;
67 buf[OMNIA_CMD_LED_COLOR_R] = mc_cdev->subled_info[0].brightness;
68 buf[OMNIA_CMD_LED_COLOR_G] = mc_cdev->subled_info[1].brightness;
69 buf[OMNIA_CMD_LED_COLOR_B] = mc_cdev->subled_info[2].brightness;
70
71 state = CMD_LED_STATE_LED(led->reg);
72 if (buf[OMNIA_CMD_LED_COLOR_R] || buf[OMNIA_CMD_LED_COLOR_G] || buf[OMNIA_CMD_LED_COLOR_B])
73 state |= CMD_LED_STATE_ON;
74
75 ret = i2c_smbus_write_byte_data(leds->client, CMD_LED_STATE, state);
76 if (ret >= 0 && (state & CMD_LED_STATE_ON))
77 ret = i2c_master_send(leds->client, buf, 5);
78
79 mutex_unlock(&leds->lock);
80
81 return ret;
82 }
83
omnia_led_register(struct i2c_client * client,struct omnia_led * led,struct device_node * np)84 static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
85 struct device_node *np)
86 {
87 struct led_init_data init_data = {};
88 struct device *dev = &client->dev;
89 struct led_classdev *cdev;
90 int ret, color;
91
92 ret = of_property_read_u32(np, "reg", &led->reg);
93 if (ret || led->reg >= OMNIA_BOARD_LEDS) {
94 dev_warn(dev,
95 "Node %pOF: must contain 'reg' property with values between 0 and %i\n",
96 np, OMNIA_BOARD_LEDS - 1);
97 return 0;
98 }
99
100 ret = of_property_read_u32(np, "color", &color);
101 if (ret || color != LED_COLOR_ID_MULTI) {
102 dev_warn(dev,
103 "Node %pOF: must contain 'color' property with value LED_COLOR_ID_MULTI\n",
104 np);
105 return 0;
106 }
107
108 led->subled_info[0].color_index = LED_COLOR_ID_RED;
109 led->subled_info[0].channel = 0;
110 led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
111 led->subled_info[1].channel = 1;
112 led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
113 led->subled_info[2].channel = 2;
114
115 led->mc_cdev.subled_info = led->subled_info;
116 led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;
117
118 init_data.fwnode = &np->fwnode;
119
120 cdev = &led->mc_cdev.led_cdev;
121 cdev->max_brightness = 255;
122 cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;
123
124 /* put the LED into software mode */
125 ret = i2c_smbus_write_byte_data(client, CMD_LED_MODE,
126 CMD_LED_MODE_LED(led->reg) |
127 CMD_LED_MODE_USER);
128 if (ret < 0) {
129 dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np, ret);
130 return ret;
131 }
132
133 /* disable the LED */
134 ret = i2c_smbus_write_byte_data(client, CMD_LED_STATE, CMD_LED_STATE_LED(led->reg));
135 if (ret < 0) {
136 dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
137 return ret;
138 }
139
140 ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev, &init_data);
141 if (ret < 0) {
142 dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
143 return ret;
144 }
145
146 return 1;
147 }
148
149 /*
150 * On the front panel of the Turris Omnia router there is also a button which
151 * can be used to control the intensity of all the LEDs at once, so that if they
152 * are too bright, user can dim them.
153 * The microcontroller cycles between 8 levels of this global brightness (from
154 * 100% to 0%), but this setting can have any integer value between 0 and 100.
155 * It is therefore convenient to be able to change this setting from software.
156 * We expose this setting via a sysfs attribute file called "brightness". This
157 * file lives in the device directory of the LED controller, not an individual
158 * LED, so it should not confuse users.
159 */
brightness_show(struct device * dev,struct device_attribute * a,char * buf)160 static ssize_t brightness_show(struct device *dev, struct device_attribute *a, char *buf)
161 {
162 struct i2c_client *client = to_i2c_client(dev);
163 struct omnia_leds *leds = i2c_get_clientdata(client);
164 int ret;
165
166 mutex_lock(&leds->lock);
167 ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS);
168 mutex_unlock(&leds->lock);
169
170 if (ret < 0)
171 return ret;
172
173 return sprintf(buf, "%d\n", ret);
174 }
175
brightness_store(struct device * dev,struct device_attribute * a,const char * buf,size_t count)176 static ssize_t brightness_store(struct device *dev, struct device_attribute *a, const char *buf,
177 size_t count)
178 {
179 struct i2c_client *client = to_i2c_client(dev);
180 struct omnia_leds *leds = i2c_get_clientdata(client);
181 unsigned int brightness;
182 int ret;
183
184 if (sscanf(buf, "%u", &brightness) != 1)
185 return -EINVAL;
186
187 if (brightness > 100)
188 return -EINVAL;
189
190 mutex_lock(&leds->lock);
191 ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS, (u8) brightness);
192 mutex_unlock(&leds->lock);
193
194 if (ret < 0)
195 return ret;
196
197 return count;
198 }
199 static DEVICE_ATTR_RW(brightness);
200
201 static struct attribute *omnia_led_controller_attrs[] = {
202 &dev_attr_brightness.attr,
203 NULL,
204 };
205 ATTRIBUTE_GROUPS(omnia_led_controller);
206
omnia_leds_probe(struct i2c_client * client,const struct i2c_device_id * id)207 static int omnia_leds_probe(struct i2c_client *client,
208 const struct i2c_device_id *id)
209 {
210 struct device *dev = &client->dev;
211 struct device_node *np = dev_of_node(dev), *child;
212 struct omnia_leds *leds;
213 struct omnia_led *led;
214 int ret, count;
215
216 count = of_get_available_child_count(np);
217 if (!count) {
218 dev_err(dev, "LEDs are not defined in device tree!\n");
219 return -ENODEV;
220 } else if (count > OMNIA_BOARD_LEDS) {
221 dev_err(dev, "Too many LEDs defined in device tree!\n");
222 return -EINVAL;
223 }
224
225 leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
226 if (!leds)
227 return -ENOMEM;
228
229 leds->client = client;
230 i2c_set_clientdata(client, leds);
231
232 mutex_init(&leds->lock);
233
234 led = &leds->leds[0];
235 for_each_available_child_of_node(np, child) {
236 ret = omnia_led_register(client, led, child);
237 if (ret < 0) {
238 of_node_put(child);
239 return ret;
240 }
241
242 led += ret;
243 }
244
245 if (devm_device_add_groups(dev, omnia_led_controller_groups))
246 dev_warn(dev, "Could not add attribute group!\n");
247
248 return 0;
249 }
250
omnia_leds_remove(struct i2c_client * client)251 static int omnia_leds_remove(struct i2c_client *client)
252 {
253 u8 buf[OMNIA_CMD_LED_COLOR_LEN];
254
255 /* put all LEDs into default (HW triggered) mode */
256 i2c_smbus_write_byte_data(client, CMD_LED_MODE,
257 CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));
258
259 /* set all LEDs color to [255, 255, 255] */
260 buf[OMNIA_CMD] = CMD_LED_COLOR;
261 buf[OMNIA_CMD_LED_COLOR_LED] = OMNIA_BOARD_LEDS;
262 buf[OMNIA_CMD_LED_COLOR_R] = 255;
263 buf[OMNIA_CMD_LED_COLOR_G] = 255;
264 buf[OMNIA_CMD_LED_COLOR_B] = 255;
265
266 i2c_master_send(client, buf, 5);
267
268 return 0;
269 }
270
271 static const struct of_device_id of_omnia_leds_match[] = {
272 { .compatible = "cznic,turris-omnia-leds", },
273 {},
274 };
275
276 static const struct i2c_device_id omnia_id[] = {
277 { "omnia", 0 },
278 { }
279 };
280
281 static struct i2c_driver omnia_leds_driver = {
282 .probe = omnia_leds_probe,
283 .remove = omnia_leds_remove,
284 .id_table = omnia_id,
285 .driver = {
286 .name = "leds-turris-omnia",
287 .of_match_table = of_omnia_leds_match,
288 },
289 };
290
291 module_i2c_driver(omnia_leds_driver);
292
293 MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
294 MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs");
295 MODULE_LICENSE("GPL v2");
296
