target/linux/mediatek/files/drivers/leds/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
  35 struct ubnt_ledbar {
  36         struct mutex lock;
  37         struct i2c_client *client;
  38         struct led_classdev led_red;
  39         struct led_classdev led_green;
  40         struct led_classdev led_blue;
  41         struct gpio_desc *enable_gpio;
  42 };
  43
  44 static void ubnt_ledbar_perform_transaction(struct ubnt_ledbar *ledbar,
  45                                            const char *transaction, int len,
  46                                            char *result, int result_len)
  47 {
  48         int i;
  49
  50         for (i = 0; i < len; i++)
  51                 i2c_smbus_write_byte(ledbar->client, transaction[i]);
  52
  53         for (i = 0; i < result_len; i++)
  54                 result[i] = i2c_smbus_read_byte(ledbar->client);
  55 }
  56
  57 static int ubnt_ledbar_apply_state(struct ubnt_ledbar *ledbar)
  58 {
  59         char setup_msg[UBNT_LEDBAR_TRANSACTION_LENGTH] = {0x40, 0x10, 0x00, 0x00,
  60                                                           0x00, 0x00, 0x00, 0x11};
  61         char led_msg[UBNT_LEDBAR_TRANSACTION_LENGTH] = {0x40, 0x00, 0x00, 0x00,
  62                                                         0x00, 0x00, 0x01, 0x00};
  63         char i2c_response;
  64         int ret = 0;
  65
  66         mutex_lock(&ledbar->lock);
  67
  68         led_msg[UBNT_LEDBAR_TRANSACTION_BLUE_IDX] = ledbar->led_blue.brightness;
  69         led_msg[UBNT_LEDBAR_TRANSACTION_GREEN_IDX] = ledbar->led_green.brightness;
  70         led_msg[UBNT_LEDBAR_TRANSACTION_RED_IDX] = ledbar->led_red.brightness;
  71
  72         gpiod_set_value(ledbar->enable_gpio, 1);
  73
  74         msleep(10);
  75
  76         ubnt_ledbar_perform_transaction(ledbar, setup_msg, sizeof(setup_msg), &i2c_response, sizeof(i2c_response));
  77         if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
  78                 dev_err(&ledbar->client->dev, "Error initializing LED transaction: %02hhx\n", i2c_response);
  79                 ret = -EINVAL;
  80                 goto out_gpio;
  81         }
  82
  83         ubnt_ledbar_perform_transaction(ledbar, led_msg, sizeof(led_msg), &i2c_response, sizeof(i2c_response));
  84         if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
  85                 dev_err(&ledbar->client->dev, "Failed LED transaction: %02hhx\n", i2c_response);
  86                 ret = -EINVAL;
  87                 goto out_gpio;
  88         }
  89
  90         msleep(10);
  91 out_gpio:
  92         gpiod_set_value(ledbar->enable_gpio, 0);
  93
  94         mutex_unlock(&ledbar->lock);
  95
  96         return ret;
  97 }
  98
  99 #define UBNT_LEDBAR_CONTROL_RGBS(name)                          \
 100 static int ubnt_ledbar_set_##name##_brightness(struct led_classdev *led_cdev,\
 101                                         enum led_brightness value)      \
 102 {                                                                       \
 103         struct ubnt_ledbar *ledbar = \
 104                         container_of(led_cdev, struct ubnt_ledbar, led_##name); \
 105         int ret; \
 106         led_cdev->brightness = value; \
 107         ret = ubnt_ledbar_apply_state(ledbar); \
 108         return ret; \
 109 }
 110
 111 UBNT_LEDBAR_CONTROL_RGBS(red);
 112 UBNT_LEDBAR_CONTROL_RGBS(green);
 113 UBNT_LEDBAR_CONTROL_RGBS(blue);
 114
 115
 116 static int ubnt_ledbar_init_led(struct device_node *np, struct ubnt_ledbar *ledbar,
 117                                 struct led_classdev *led_cdev)
 118 {
 119         struct led_init_data init_data = {};
 120         int ret;
 121
 122         if (!np)
 123                 return 0;
 124
 125         init_data.fwnode = of_fwnode_handle(np);
 126
 127         led_cdev->max_brightness = UBNT_LEDBAR_MAX_BRIGHTNESS;
 128
 129         ret = devm_led_classdev_register_ext(&ledbar->client->dev, led_cdev,
 130                                              &init_data);
 131         if (ret)
 132                 dev_err(&ledbar->client->dev, "led register err: %d\n", ret);
 133
 134         return ret;
 135 }
 136
 137
 138 static int ubnt_ledbar_probe(struct i2c_client *client,
 139                              const struct i2c_device_id *id)
 140 {
 141         struct device_node *np = client->dev.of_node;
 142         struct ubnt_ledbar *ledbar;
 143         int ret;
 144
 145         ledbar = devm_kzalloc(&client->dev, sizeof(*ledbar), GFP_KERNEL);
 146         if (!ledbar)
 147                 return -ENOMEM;
 148
 149         ledbar->enable_gpio = devm_gpiod_get(&client->dev, "enable", GPIOD_OUT_LOW);
 150
 151         if (IS_ERR(ledbar->enable_gpio)) {
 152                 ret = PTR_ERR(ledbar->enable_gpio);
 153                 dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret);
 154                 return ret;
 155         }
 156
 157         ledbar->client = client;
 158
 159         mutex_init(&ledbar->lock);
 160
 161         i2c_set_clientdata(client, ledbar);
 162
 163         ledbar->led_red.brightness_set_blocking = ubnt_ledbar_set_red_brightness;
 164         ubnt_ledbar_init_led(of_get_child_by_name(np, "red"), ledbar, &ledbar->led_red);
 165
 166         ledbar->led_green.brightness_set_blocking = ubnt_ledbar_set_green_brightness;
 167         ubnt_ledbar_init_led(of_get_child_by_name(np, "green"), ledbar, &ledbar->led_green);
 168
 169         ledbar->led_blue.brightness_set_blocking = ubnt_ledbar_set_blue_brightness;
 170         ubnt_ledbar_init_led(of_get_child_by_name(np, "blue"), ledbar, &ledbar->led_blue);
 171
 172         return ubnt_ledbar_apply_state(ledbar);
 173 }
 174
 175 static int ubnt_ledbar_remove(struct i2c_client *client)
 176 {
 177         struct ubnt_ledbar *ledbar = i2c_get_clientdata(client);
 178
 179         mutex_destroy(&ledbar->lock);
 180
 181         return 0;
 182 }
 183
 184 static const struct i2c_device_id ubnt_ledbar_id[] = {
 185         { "ubnt-ledbar", 0 },
 186         { }
 187 };
 188 MODULE_DEVICE_TABLE(i2c, ubnt_ledbar_id);
 189
 190 static const struct of_device_id of_ubnt_ledbar_match[] = {
 191         { .compatible = "ubnt,ledbar", },
 192         {},
 193 };
 194 MODULE_DEVICE_TABLE(of, of_ubnt_ledbar_match);
 195
 196 static struct i2c_driver ubnt_ledbar_driver = {
 197         .driver = {
 198                 .name   = "ubnt-ledbar",
 199                 .of_match_table = of_ubnt_ledbar_match,
 200         },
 201         .probe          = ubnt_ledbar_probe,
 202         .remove         = ubnt_ledbar_remove,
 203         .id_table       = ubnt_ledbar_id,
 204 };
 205 module_i2c_driver(ubnt_ledbar_driver);
 206
 207 MODULE_DESCRIPTION("Ubiquiti LEDBAR driver");
 208 MODULE_AUTHOR("David Bauer <mail@david-bauer.net>");
 209 MODULE_LICENSE("GPL v2");