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