1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * CZ.NIC's Turris Omnia LEDs driver
4 *
5 * 2020, 2023 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_cmd_write_u8(const struct i2c_client * client,u8 cmd,u8 val)44 static int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd, u8 val)
45 {
46 u8 buf[2] = { cmd, val };
47
48 return i2c_master_send(client, buf, sizeof(buf));
49 }
50
omnia_cmd_read_u8(const struct i2c_client * client,u8 cmd)51 static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
52 {
53 struct i2c_msg msgs[2];
54 u8 reply;
55 int ret;
56
57 msgs[0].addr = client->addr;
58 msgs[0].flags = 0;
59 msgs[0].len = 1;
60 msgs[0].buf = &cmd;
61 msgs[1].addr = client->addr;
62 msgs[1].flags = I2C_M_RD;
63 msgs[1].len = 1;
64 msgs[1].buf = &reply;
65
66 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
67 if (likely(ret == ARRAY_SIZE(msgs)))
68 return reply;
69 else if (ret < 0)
70 return ret;
71 else
72 return -EIO;
73 }
74
omnia_led_brightness_set_blocking(struct led_classdev * cdev,enum led_brightness brightness)75 static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
76 enum led_brightness brightness)
77 {
78 struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
79 struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
80 struct omnia_led *led = to_omnia_led(mc_cdev);
81 u8 buf[5], state;
82 int ret;
83
84 mutex_lock(&leds->lock);
85
86 led_mc_calc_color_components(&led->mc_cdev, brightness);
87
88 buf[0] = CMD_LED_COLOR;
89 buf[1] = led->reg;
90 buf[2] = mc_cdev->subled_info[0].brightness;
91 buf[3] = mc_cdev->subled_info[1].brightness;
92 buf[4] = mc_cdev->subled_info[2].brightness;
93
94 state = CMD_LED_STATE_LED(led->reg);
95 if (buf[2] || buf[3] || buf[4])
96 state |= CMD_LED_STATE_ON;
97
98 ret = omnia_cmd_write_u8(leds->client, CMD_LED_STATE, state);
99 if (ret >= 0 && (state & CMD_LED_STATE_ON))
100 ret = i2c_master_send(leds->client, buf, 5);
101
102 mutex_unlock(&leds->lock);
103
104 return ret;
105 }
106
omnia_led_register(struct i2c_client * client,struct omnia_led * led,struct device_node * np)107 static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
108 struct device_node *np)
109 {
110 struct led_init_data init_data = {};
111 struct device *dev = &client->dev;
112 struct led_classdev *cdev;
113 int ret, color;
114
115 ret = of_property_read_u32(np, "reg", &led->reg);
116 if (ret || led->reg >= OMNIA_BOARD_LEDS) {
117 dev_warn(dev,
118 "Node %pOF: must contain 'reg' property with values between 0 and %i\n",
119 np, OMNIA_BOARD_LEDS - 1);
120 return 0;
121 }
122
123 ret = of_property_read_u32(np, "color", &color);
124 if (ret || color != LED_COLOR_ID_RGB) {
125 dev_warn(dev,
126 "Node %pOF: must contain 'color' property with value LED_COLOR_ID_RGB\n",
127 np);
128 return 0;
129 }
130
131 led->subled_info[0].color_index = LED_COLOR_ID_RED;
132 led->subled_info[0].channel = 0;
133 led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
134 led->subled_info[1].channel = 1;
135 led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
136 led->subled_info[2].channel = 2;
137
138 led->mc_cdev.subled_info = led->subled_info;
139 led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;
140
141 init_data.fwnode = &np->fwnode;
142
143 cdev = &led->mc_cdev.led_cdev;
144 cdev->max_brightness = 255;
145 cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;
146
147 /* put the LED into software mode */
148 ret = omnia_cmd_write_u8(client, CMD_LED_MODE,
149 CMD_LED_MODE_LED(led->reg) |
150 CMD_LED_MODE_USER);
151 if (ret < 0) {
152 dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
153 ret);
154 return ret;
155 }
156
157 /* disable the LED */
158 ret = omnia_cmd_write_u8(client, CMD_LED_STATE,
159 CMD_LED_STATE_LED(led->reg));
160 if (ret < 0) {
161 dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
162 return ret;
163 }
164
165 ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
166 &init_data);
167 if (ret < 0) {
168 dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
169 return ret;
170 }
171
172 return 1;
173 }
174
175 /*
176 * On the front panel of the Turris Omnia router there is also a button which
177 * can be used to control the intensity of all the LEDs at once, so that if they
178 * are too bright, user can dim them.
179 * The microcontroller cycles between 8 levels of this global brightness (from
180 * 100% to 0%), but this setting can have any integer value between 0 and 100.
181 * It is therefore convenient to be able to change this setting from software.
182 * We expose this setting via a sysfs attribute file called "brightness". This
183 * file lives in the device directory of the LED controller, not an individual
184 * LED, so it should not confuse users.
185 */
brightness_show(struct device * dev,struct device_attribute * a,char * buf)186 static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
187 char *buf)
188 {
189 struct i2c_client *client = to_i2c_client(dev);
190 int ret;
191
192 ret = omnia_cmd_read_u8(client, CMD_LED_GET_BRIGHTNESS);
193
194 if (ret < 0)
195 return ret;
196
197 return sysfs_emit(buf, "%d\n", ret);
198 }
199
brightness_store(struct device * dev,struct device_attribute * a,const char * buf,size_t count)200 static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
201 const char *buf, size_t count)
202 {
203 struct i2c_client *client = to_i2c_client(dev);
204 unsigned long brightness;
205 int ret;
206
207 if (kstrtoul(buf, 10, &brightness))
208 return -EINVAL;
209
210 if (brightness > 100)
211 return -EINVAL;
212
213 ret = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);
214
215 return ret < 0 ? ret : count;
216 }
217 static DEVICE_ATTR_RW(brightness);
218
219 static struct attribute *omnia_led_controller_attrs[] = {
220 &dev_attr_brightness.attr,
221 NULL,
222 };
223 ATTRIBUTE_GROUPS(omnia_led_controller);
224
omnia_leds_probe(struct i2c_client * client)225 static int omnia_leds_probe(struct i2c_client *client)
226 {
227 struct device *dev = &client->dev;
228 struct device_node *np = dev_of_node(dev), *child;
229 struct omnia_leds *leds;
230 struct omnia_led *led;
231 int ret, count;
232
233 count = of_get_available_child_count(np);
234 if (!count) {
235 dev_err(dev, "LEDs are not defined in device tree!\n");
236 return -ENODEV;
237 } else if (count > OMNIA_BOARD_LEDS) {
238 dev_err(dev, "Too many LEDs defined in device tree!\n");
239 return -EINVAL;
240 }
241
242 leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
243 if (!leds)
244 return -ENOMEM;
245
246 leds->client = client;
247 i2c_set_clientdata(client, leds);
248
249 mutex_init(&leds->lock);
250
251 led = &leds->leds[0];
252 for_each_available_child_of_node(np, child) {
253 ret = omnia_led_register(client, led, child);
254 if (ret < 0) {
255 of_node_put(child);
256 return ret;
257 }
258
259 led += ret;
260 }
261
262 return 0;
263 }
264
omnia_leds_remove(struct i2c_client * client)265 static void omnia_leds_remove(struct i2c_client *client)
266 {
267 u8 buf[5];
268
269 /* put all LEDs into default (HW triggered) mode */
270 omnia_cmd_write_u8(client, CMD_LED_MODE,
271 CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));
272
273 /* set all LEDs color to [255, 255, 255] */
274 buf[0] = CMD_LED_COLOR;
275 buf[1] = OMNIA_BOARD_LEDS;
276 buf[2] = 255;
277 buf[3] = 255;
278 buf[4] = 255;
279
280 i2c_master_send(client, buf, 5);
281 }
282
283 static const struct of_device_id of_omnia_leds_match[] = {
284 { .compatible = "cznic,turris-omnia-leds", },
285 {},
286 };
287
288 static const struct i2c_device_id omnia_id[] = {
289 { "omnia", 0 },
290 { }
291 };
292 MODULE_DEVICE_TABLE(i2c, omnia_id);
293
294 static struct i2c_driver omnia_leds_driver = {
295 .probe = omnia_leds_probe,
296 .remove = omnia_leds_remove,
297 .id_table = omnia_id,
298 .driver = {
299 .name = "leds-turris-omnia",
300 .of_match_table = of_omnia_leds_match,
301 .dev_groups = omnia_led_controller_groups,
302 },
303 };
304
305 module_i2c_driver(omnia_leds_driver);
306
307 MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
308 MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs");
309 MODULE_LICENSE("GPL v2");
310