package/kernel/ubnt-ledbar/src/leds-ubnt-ledbar.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 #include <linux/delay.h>
   4 #include <linux/i2c.h>
   5 #include <linux/init.h>
   6 #include <linux/leds.h>
   7 #include <linux/module.h>
   8 #include <linux/mutex.h>
   9 #include <linux/of.h>
  10 #include <linux/of_gpio.h>
  11 #include <linux/gpio/consumer.h>
  12
  13 /**
  14  * Driver for the Ubiquiti RGB LED controller (LEDBAR).
  15  * This Controller is based on a Holtek HT32F52241 and connected
  16  * via I2C.
  17  *
  18  *  - The Controller needs an enable signal set to high when
  19  *    performing a transaction. On the U6-LR, this is located
  20  *    at Pin 18 (R6902)
  21  *
  22  *  - The Pin is also printed when calling the "usetled" function
  23  *    contained in the ubntapp bootloader application.
  24  */
  25
  26 #define UBNT_LEDBAR_MAX_BRIGHTNESS      0xff
  27
  28 #define UBNT_LEDBAR_TRANSACTION_LENGTH  8
  29 #define UBNT_LEDBAR_TRANSACTION_SUCCESS (char) 0xaa
  30
  31 #define UBNT_LEDBAR_TRANSACTION_BLUE_IDX        2
  32 #define UBNT_LEDBAR_TRANSACTION_GREEN_IDX       3
  33 #define UBNT_LEDBAR_TRANSACTION_RED_IDX         4
  34 #define UBNT_LEDBAR_TRANSACTION_LED_COUNT_IDX   6
  35
  36 struct ubnt_ledbar {
  37         struct mutex lock;
  38         u32 led_count;
  39         struct i2c_client *client;
  40         struct led_classdev led_red;
  41         struct led_classdev led_green;
  42         struct led_classdev led_blue;
  43         struct gpio_desc *enable_gpio;
  44         struct gpio_desc *reset_gpio;
  45 };
  46
  47 static void ubnt_ledbar_perform_transaction(struct ubnt_ledbar *ledbar,
  48                                            const char *transaction, int len,
  49                                            char *result, int result_len)
  50 {
  51         int i;
  52
  53         for (i = 0; i < len; i++)
  54                 i2c_smbus_write_byte(ledbar->client, transaction[i]);
  55
  56         for (i = 0; i < result_len; i++)
  57                 result[i] = i2c_smbus_read_byte(ledbar->client);
  58 }
  59
  60 static int ubnt_ledbar_apply_state(struct ubnt_ledbar *ledbar)
  61 {
  62         char setup_msg[UBNT_LEDBAR_TRANSACTION_LENGTH] = {0x40, 0x10, 0x00, 0x00,
  63                                                           0x00, 0x00, 0x00, 0x11};
  64         char led_msg[UBNT_LEDBAR_TRANSACTION_LENGTH] = {0x40, 0x00, 0x00, 0x00,
  65                                                         0x00, 0x00, 0x00, 0x00};
  66         char i2c_response;
  67         int ret = 0;
  68
  69         mutex_lock(&ledbar->lock);
  70
  71         led_msg[UBNT_LEDBAR_TRANSACTION_BLUE_IDX] = ledbar->led_blue.brightness;
  72         led_msg[UBNT_LEDBAR_TRANSACTION_GREEN_IDX] = ledbar->led_green.brightness;
  73         led_msg[UBNT_LEDBAR_TRANSACTION_RED_IDX] = ledbar->led_red.brightness;
  74         led_msg[UBNT_LEDBAR_TRANSACTION_LED_COUNT_IDX] = ledbar->led_count;
  75
  76         gpiod_set_value(ledbar->enable_gpio, 1);
  77
  78         msleep(10);
  79
  80         ubnt_ledbar_perform_transaction(ledbar, setup_msg, sizeof(setup_msg), &i2c_response, sizeof(i2c_response));
  81         if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
  82                 dev_err(&ledbar->client->dev, "Error initializing LED transaction: %02hhx\n", i2c_response);
  83                 ret = -EINVAL;
  84                 goto out_gpio;
  85         }
  86
  87         ubnt_ledbar_perform_transaction(ledbar, led_msg, sizeof(led_msg), &i2c_response, sizeof(i2c_response));
  88         if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
  89                 dev_err(&ledbar->client->dev, "Failed LED transaction: %02hhx\n", i2c_response);
  90                 ret = -EINVAL;
  91                 goto out_gpio;
  92         }
  93
  94         msleep(10);
  95 out_gpio:
  96         gpiod_set_value(ledbar->enable_gpio, 0);
  97
  98         mutex_unlock(&ledbar->lock);
  99
 100         return ret;
 101 }
 102
 103 static void ubnt_ledbar_reset(struct ubnt_ledbar *ledbar)
 104 {
 105         static const char init_msg[16] = {0x02, 0x81, 0xfd, 0x7e,
 106                                           0x00, 0x00, 0x00, 0x00,
 107                                           0x00, 0x00, 0x00, 0x00,
 108                                           0x00, 0x00, 0x00, 0x00};
 109         char init_response[4];
 110
 111         if (!ledbar->reset_gpio)
 112                 return;
 113
 114         mutex_lock(&ledbar->lock);
 115
 116         gpiod_set_value(ledbar->reset_gpio, 1);
 117         msleep(10);
 118         gpiod_set_value(ledbar->reset_gpio, 0);
 119
 120         msleep(10);
 121
 122         gpiod_set_value(ledbar->enable_gpio, 1);
 123         msleep(10);
 124         ubnt_ledbar_perform_transaction(ledbar, init_msg, sizeof(init_msg), init_response, sizeof(init_response));
 125         msleep(10);
 126         gpiod_set_value(ledbar->enable_gpio, 0);
 127
 128         mutex_unlock(&ledbar->lock);
 129 }
 130
 131 #define UBNT_LEDBAR_CONTROL_RGBS(name)                          \
 132 static int ubnt_ledbar_set_##name##_brightness(struct led_classdev *led_cdev,\
 133                                         enum led_brightness value)      \
 134 {                                                                       \
 135         struct ubnt_ledbar *ledbar = \
 136                         container_of(led_cdev, struct ubnt_ledbar, led_##name); \
 137         int ret; \
 138         led_cdev->brightness = value; \
 139         ret = ubnt_ledbar_apply_state(ledbar); \
 140         return ret; \
 141 }
 142
 143 UBNT_LEDBAR_CONTROL_RGBS(red);
 144 UBNT_LEDBAR_CONTROL_RGBS(green);
 145 UBNT_LEDBAR_CONTROL_RGBS(blue);
 146
 147
 148 static int ubnt_ledbar_init_led(struct device_node *np, struct ubnt_ledbar *ledbar,
 149                                 struct led_classdev *led_cdev)
 150 {
 151         struct led_init_data init_data = {};
 152         int ret;
 153
 154         if (!np)
 155                 return 0;
 156
 157         init_data.fwnode = of_fwnode_handle(np);
 158
 159         led_cdev->max_brightness = UBNT_LEDBAR_MAX_BRIGHTNESS;
 160
 161         ret = devm_led_classdev_register_ext(&ledbar->client->dev, led_cdev,
 162                                              &init_data);
 163         if (ret)
 164                 dev_err(&ledbar->client->dev, "led register err: %d\n", ret);
 165
 166         return ret;
 167 }
 168
 169
 170 static int ubnt_ledbar_probe(struct i2c_client *client,
 171                              const struct i2c_device_id *id)
 172 {
 173         struct device_node *np = client->dev.of_node;
 174         struct ubnt_ledbar *ledbar;
 175         int ret;
 176
 177         ledbar = devm_kzalloc(&client->dev, sizeof(*ledbar), GFP_KERNEL);
 178         if (!ledbar)
 179                 return -ENOMEM;
 180
 181         ledbar->enable_gpio = devm_gpiod_get(&client->dev, "enable", GPIOD_OUT_LOW);
 182
 183         if (IS_ERR(ledbar->enable_gpio)) {
 184                 ret = PTR_ERR(ledbar->enable_gpio);
 185                 dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
 186                 return ret;
 187         }
 188
 189         ledbar->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
 190
 191         if (IS_ERR(ledbar->reset_gpio)) {
 192                 ret = PTR_ERR(ledbar->reset_gpio);
 193                 dev_err(&client->dev, "Failed to get reset gpio: %d\n", ret);
 194                 return ret;
 195         }
 196
 197         ledbar->led_count = 1;
 198         of_property_read_u32(np, "led-count", &ledbar->led_count);
 199
 200         ledbar->client = client;
 201
 202         mutex_init(&ledbar->lock);
 203
 204         i2c_set_clientdata(client, ledbar);
 205
 206         // Reset and initialize the MCU
 207         ubnt_ledbar_reset(ledbar);
 208
 209         ledbar->led_red.brightness_set_blocking = ubnt_ledbar_set_red_brightness;
 210         ubnt_ledbar_init_led(of_get_child_by_name(np, "red"), ledbar, &ledbar->led_red);
 211
 212         ledbar->led_green.brightness_set_blocking = ubnt_ledbar_set_green_brightness;
 213         ubnt_ledbar_init_led(of_get_child_by_name(np, "green"), ledbar, &ledbar->led_green);
 214
 215         ledbar->led_blue.brightness_set_blocking = ubnt_ledbar_set_blue_brightness;
 216         ubnt_ledbar_init_led(of_get_child_by_name(np, "blue"), ledbar, &ledbar->led_blue);
 217
 218         return ubnt_ledbar_apply_state(ledbar);
 219 }
 220
 221 static int ubnt_ledbar_remove(struct i2c_client *client)
 222 {
 223         struct ubnt_ledbar *ledbar = i2c_get_clientdata(client);
 224
 225         mutex_destroy(&ledbar->lock);
 226
 227         return 0;
 228 }
 229
 230 static const struct i2c_device_id ubnt_ledbar_id[] = {
 231         { "ubnt-ledbar", 0 },
 232         { }
 233 };
 234 MODULE_DEVICE_TABLE(i2c, ubnt_ledbar_id);
 235
 236 static const struct of_device_id of_ubnt_ledbar_match[] = {
 237         { .compatible = "ubnt,ledbar", },
 238         {},
 239 };
 240 MODULE_DEVICE_TABLE(of, of_ubnt_ledbar_match);
 241
 242 static struct i2c_driver ubnt_ledbar_driver = {
 243         .driver = {
 244                 .name   = "ubnt-ledbar",
 245                 .of_match_table = of_ubnt_ledbar_match,
 246         },
 247         .probe          = ubnt_ledbar_probe,
 248         .remove         = ubnt_ledbar_remove,
 249         .id_table       = ubnt_ledbar_id,
 250 };
 251 module_i2c_driver(ubnt_ledbar_driver);
 252
 253 MODULE_DESCRIPTION("Ubiquiti LEDBAR driver");
 254 MODULE_AUTHOR("David Bauer <mail@david-bauer.net>");
 255 MODULE_LICENSE("GPL v2");