drivers/leds/leds-menf21bmc.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  *  MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
0004  *
0005  *  This is the core LED driver of the MEN 14F021P00 BMC.
0006  *  There are four LEDs available which can be switched on and off.
0007  *  STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
0008  *
0009  *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
0010  */
0011
0012 #include <linux/module.h>
0013 #include <linux/kernel.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/leds.h>
0016 #include <linux/i2c.h>
0017
0018 #define BMC_CMD_LED_GET_SET 0xA0
0019 #define BMC_BIT_LED_STATUS  BIT(0)
0020 #define BMC_BIT_LED_HOTSWAP BIT(1)
0021 #define BMC_BIT_LED_USER1   BIT(2)
0022 #define BMC_BIT_LED_USER2   BIT(3)
0023
0024 struct menf21bmc_led {
0025     struct led_classdev cdev;
0026     u8 led_bit;
0027     const char *name;
0028     struct i2c_client *i2c_client;
0029 };
0030
0031 static struct menf21bmc_led leds[] = {
0032     {
0033         .name = "menf21bmc:led_status",
0034         .led_bit = BMC_BIT_LED_STATUS,
0035     },
0036     {
0037         .name = "menf21bmc:led_hotswap",
0038         .led_bit = BMC_BIT_LED_HOTSWAP,
0039     },
0040     {
0041         .name = "menf21bmc:led_user1",
0042         .led_bit = BMC_BIT_LED_USER1,
0043     },
0044     {
0045         .name = "menf21bmc:led_user2",
0046         .led_bit = BMC_BIT_LED_USER2,
0047     }
0048 };
0049
0050 static DEFINE_MUTEX(led_lock);
0051
0052 static void
0053 menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
0054 {
0055     int led_val;
0056     struct menf21bmc_led *led = container_of(led_cdev,
0057                     struct menf21bmc_led, cdev);
0058
0059     mutex_lock(&led_lock);
0060     led_val = i2c_smbus_read_byte_data(led->i2c_client,
0061                        BMC_CMD_LED_GET_SET);
0062     if (led_val < 0)
0063         goto err_out;
0064
0065     if (value == LED_OFF)
0066         led_val &= ~led->led_bit;
0067     else
0068         led_val |= led->led_bit;
0069
0070     i2c_smbus_write_byte_data(led->i2c_client,
0071                   BMC_CMD_LED_GET_SET, led_val);
0072 err_out:
0073     mutex_unlock(&led_lock);
0074 }
0075
0076 static int menf21bmc_led_probe(struct platform_device *pdev)
0077 {
0078     int i;
0079     int ret;
0080     struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
0081
0082     for (i = 0; i < ARRAY_SIZE(leds); i++) {
0083         leds[i].cdev.name = leds[i].name;
0084         leds[i].cdev.brightness_set = menf21bmc_led_set;
0085         leds[i].i2c_client = i2c_client;
0086         ret = devm_led_classdev_register(&pdev->dev, &leds[i].cdev);
0087         if (ret < 0) {
0088             dev_err(&pdev->dev, "failed to register LED device\n");
0089             return ret;
0090         }
0091     }
0092     dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
0093
0094     return 0;
0095
0096 }
0097
0098 static struct platform_driver menf21bmc_led = {
0099     .probe      = menf21bmc_led_probe,
0100     .driver     = {
0101         .name       = "menf21bmc_led",
0102     },
0103 };
0104
0105 module_platform_driver(menf21bmc_led);
0106
0107 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
0108 MODULE_DESCRIPTION("MEN 14F021P00 BMC led driver");
0109 MODULE_LICENSE("GPL v2");
0110 MODULE_ALIAS("platform:menf21bmc_led");