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 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 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 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 } 106 107 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 */ 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 } 199 200 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); 224 225 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 } 264 265 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