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 { 206 struct device *dev = &client->dev; 207 struct device_node *np = dev_of_node(dev), *child; 208 struct omnia_leds *leds; 209 struct omnia_led *led; 210 int ret, count; 211 212 count = of_get_available_child_count(np); 213 if (!count) { 214 dev_err(dev, "LEDs are not defined in device tree!\n"); 215 return -ENODEV; 216 } else if (count > OMNIA_BOARD_LEDS) { 217 dev_err(dev, "Too many LEDs defined in device tree!\n"); 218 return -EINVAL; 219 } 220 221 leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL); 222 if (!leds) 223 return -ENOMEM; 224 225 leds->client = client; 226 i2c_set_clientdata(client, leds); 227 228 mutex_init(&leds->lock); 229 230 led = &leds->leds[0]; 231 for_each_available_child_of_node(np, child) { 232 ret = omnia_led_register(client, led, child); 233 if (ret < 0) { 234 of_node_put(child); 235 return ret; 236 } 237 238 led += ret; 239 } 240 241 return 0; 242 } 243 244 static void omnia_leds_remove(struct i2c_client *client) 245 { 246 u8 buf[5]; 247 248 /* put all LEDs into default (HW triggered) mode */ 249 i2c_smbus_write_byte_data(client, CMD_LED_MODE, 250 CMD_LED_MODE_LED(OMNIA_BOARD_LEDS)); 251 252 /* set all LEDs color to [255, 255, 255] */ 253 buf[0] = CMD_LED_COLOR; 254 buf[1] = OMNIA_BOARD_LEDS; 255 buf[2] = 255; 256 buf[3] = 255; 257 buf[4] = 255; 258 259 i2c_master_send(client, buf, 5); 260 } 261 262 static const struct of_device_id of_omnia_leds_match[] = { 263 { .compatible = "cznic,turris-omnia-leds", }, 264 {}, 265 }; 266 267 static const struct i2c_device_id omnia_id[] = { 268 { "omnia", 0 }, 269 { } 270 }; 271 MODULE_DEVICE_TABLE(i2c, omnia_id); 272 273 static struct i2c_driver omnia_leds_driver = { 274 .probe = omnia_leds_probe, 275 .remove = omnia_leds_remove, 276 .id_table = omnia_id, 277 .driver = { 278 .name = "leds-turris-omnia", 279 .of_match_table = of_omnia_leds_match, 280 .dev_groups = omnia_led_controller_groups, 281 }, 282 }; 283 284 module_i2c_driver(omnia_leds_driver); 285 286 MODULE_AUTHOR("Marek Behun <kabel@kernel.org>"); 287 MODULE_DESCRIPTION("CZ.NIC's Turris Omnia LEDs"); 288 MODULE_LICENSE("GPL v2"); 289