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 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 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 */ 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 struct omnia_leds *leds = i2c_get_clientdata(client); 160 int ret; 161 162 mutex_lock(&leds->lock); 163 ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS); 164 mutex_unlock(&leds->lock); 165 166 if (ret < 0) 167 return ret; 168 169 return sprintf(buf, "%d\n", ret); 170 } 171 172 static ssize_t brightness_store(struct device *dev, struct device_attribute *a, 173 const char *buf, size_t count) 174 { 175 struct i2c_client *client = to_i2c_client(dev); 176 struct omnia_leds *leds = i2c_get_clientdata(client); 177 unsigned long brightness; 178 int ret; 179 180 if (kstrtoul(buf, 10, &brightness)) 181 return -EINVAL; 182 183 if (brightness > 100) 184 return -EINVAL; 185 186 mutex_lock(&leds->lock); 187 ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS, 188 (u8)brightness); 189 mutex_unlock(&leds->lock); 190 191 if (ret < 0) 192 return ret; 193 194 return count; 195 } 196 static DEVICE_ATTR_RW(brightness); 197 198 static struct attribute *omnia_led_controller_attrs[] = { 199 &dev_attr_brightness.attr, 200 NULL, 201 }; 202 ATTRIBUTE_GROUPS(omnia_led_controller); 203 204 static int omnia_leds_probe(struct i2c_client *client, 205 const struct i2c_device_id *id) 206 { 207 struct device *dev = &client->dev; 208 struct device_node *np = dev_of_node(dev), *child; 209 struct omnia_leds *leds; 210 struct omnia_led *led; 211 int ret, count; 212 213 count = of_get_available_child_count(np); 214 if (!count) { 215 dev_err(dev, "LEDs are not defined in device tree!\n"); 216 return -ENODEV; 217 } else if (count > OMNIA_BOARD_LEDS) { 218 dev_err(dev, "Too many LEDs defined in device tree!\n"); 219 return -EINVAL; 220 } 221 222 leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL); 223 if (!leds) 224 return -ENOMEM; 225 226 leds->client = client; 227 i2c_set_clientdata(client, leds); 228 229 mutex_init(&leds->lock); 230 231 led = &leds->leds[0]; 232 for_each_available_child_of_node(np, child) { 233 ret = omnia_led_register(client, led, child); 234 if (ret < 0) { 235 of_node_put(child); 236 return ret; 237 } 238 239 led += ret; 240 } 241 242 if (devm_device_add_groups(dev, omnia_led_controller_groups)) 243 dev_warn(dev, "Could not add attribute group!\n"); 244 245 return 0; 246 } 247 248 static int omnia_leds_remove(struct i2c_client *client) 249 { 250 u8 buf[5]; 251 252 /* put all LEDs into default (HW triggered) mode */ 253 i2c_smbus_write_byte_data(client, CMD_LED_MODE, 254 CMD_LED_MODE_LED(OMNIA_BOARD_LEDS)); 255 256 /* set all LEDs color to [255, 255, 255] */ 257 buf[0] = CMD_LED_COLOR; 258 buf[1] = OMNIA_BOARD_LEDS; 259 buf[2] = 255; 260 buf[3] = 255; 261 buf[4] = 255; 262 263 i2c_master_send(client, buf, 5); 264 265 return 0; 266 } 267 268 static const struct of_device_id of_omnia_leds_match[] = { 269 { .compatible = "cznic,turris-omnia-leds", }, 270 {}, 271 }; 272 273 static const struct i2c_device_id omnia_id[] = { 274 { "omnia", 0 }, 275 { } 276 }; 277 278 static struct i2c_driver omnia_leds_driver = { 279 .probe = omnia_leds_probe, 280 .remove = omnia_leds_remove, 281 .id_table = omnia_id, 282 .driver = { 283 .name = "leds-turris-omnia", 284 .of_match_table = of_omnia_leds_match, 285 }, 286 }; 287 288 module_i2c_driver(omnia_leds_driver); 289 290 MODULE_AUTHOR("Marek Behun <kabel@kernel.org>"); 291 MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs"); 292 MODULE_LICENSE("GPL v2"); 293