drivers/leds/simple/simatic-ipc-leds.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Siemens SIMATIC IPC driver for LEDs
   4  *
   5  * Copyright (c) Siemens AG, 2018-2021
   6  *
   7  * Authors:
   8  *  Henning Schild <henning.schild@siemens.com>
   9  *  Jan Kiszka <jan.kiszka@siemens.com>
  10  *  Gerd Haeussler <gerd.haeussler.ext@siemens.com>
  11  */
  12
  13 #include <linux/ioport.h>
  14 #include <linux/kernel.h>
  15 #include <linux/leds.h>
  16 #include <linux/module.h>
  17 #include <linux/pci.h>
  18 #include <linux/platform_data/x86/simatic-ipc-base.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/sizes.h>
  21 #include <linux/spinlock.h>
  22
  23 #define SIMATIC_IPC_LED_PORT_BASE       0x404E
  24
  25 struct simatic_ipc_led {
  26         unsigned int value; /* mask for io */
  27         char *name;
  28         struct led_classdev cdev;
  29 };
  30
  31 static struct simatic_ipc_led simatic_ipc_leds_io[] = {
  32         {1 << 15, "green:" LED_FUNCTION_STATUS "-1" },
  33         {1 << 7,  "yellow:" LED_FUNCTION_STATUS "-1" },
  34         {1 << 14, "red:" LED_FUNCTION_STATUS "-2" },
  35         {1 << 6,  "yellow:" LED_FUNCTION_STATUS "-2" },
  36         {1 << 13, "red:" LED_FUNCTION_STATUS "-3" },
  37         {1 << 5,  "yellow:" LED_FUNCTION_STATUS "-3" },
  38         { }
  39 };
  40
  41 static struct resource simatic_ipc_led_io_res =
  42         DEFINE_RES_IO_NAMED(SIMATIC_IPC_LED_PORT_BASE, SZ_2, KBUILD_MODNAME);
  43
  44 static DEFINE_SPINLOCK(reg_lock);
  45
  46 static inline struct simatic_ipc_led *cdev_to_led(struct led_classdev *led_cd)
  47 {
  48         return container_of(led_cd, struct simatic_ipc_led, cdev);
  49 }
  50
  51 static void simatic_ipc_led_set_io(struct led_classdev *led_cd,
  52                                    enum led_brightness brightness)
  53 {
  54         struct simatic_ipc_led *led = cdev_to_led(led_cd);
  55         unsigned long flags;
  56         unsigned int val;
  57
  58         spin_lock_irqsave(&reg_lock, flags);
  59
  60         val = inw(SIMATIC_IPC_LED_PORT_BASE);
  61         if (brightness == LED_OFF)
  62                 outw(val | led->value, SIMATIC_IPC_LED_PORT_BASE);
  63         else
  64                 outw(val & ~led->value, SIMATIC_IPC_LED_PORT_BASE);
  65
  66         spin_unlock_irqrestore(&reg_lock, flags);
  67 }
  68
  69 static enum led_brightness simatic_ipc_led_get_io(struct led_classdev *led_cd)
  70 {
  71         struct simatic_ipc_led *led = cdev_to_led(led_cd);
  72
  73         return inw(SIMATIC_IPC_LED_PORT_BASE) & led->value ? LED_OFF : led_cd->max_brightness;
  74 }
  75
  76 static int simatic_ipc_leds_probe(struct platform_device *pdev)
  77 {
  78         const struct simatic_ipc_platform *plat = pdev->dev.platform_data;
  79         struct device *dev = &pdev->dev;
  80         struct simatic_ipc_led *ipcled;
  81         struct led_classdev *cdev;
  82         struct resource *res;
  83         int err;
  84
  85         switch (plat->devmode) {
  86         case SIMATIC_IPC_DEVICE_227D:
  87         case SIMATIC_IPC_DEVICE_427E:
  88                 res = &simatic_ipc_led_io_res;
  89                 ipcled = simatic_ipc_leds_io;
  90                 /* on 227D the two bytes work the other way araound */
  91                 if (plat->devmode == SIMATIC_IPC_DEVICE_227D) {
  92                         while (ipcled->value) {
  93                                 ipcled->value = swab16(ipcled->value);
  94                                 ipcled++;
  95                         }
  96                         ipcled = simatic_ipc_leds_io;
  97                 }
  98                 if (!devm_request_region(dev, res->start, resource_size(res), KBUILD_MODNAME)) {
  99                         dev_err(dev, "Unable to register IO resource at %pR\n", res);
 100                         return -EBUSY;
 101                 }
 102                 break;
 103         default:
 104                 return -ENODEV;
 105         }
 106
 107         while (ipcled->value) {
 108                 cdev = &ipcled->cdev;
 109                 cdev->brightness_set = simatic_ipc_led_set_io;
 110                 cdev->brightness_get = simatic_ipc_led_get_io;
 111                 cdev->max_brightness = LED_ON;
 112                 cdev->name = ipcled->name;
 113
 114                 err = devm_led_classdev_register(dev, cdev);
 115                 if (err < 0)
 116                         return err;
 117                 ipcled++;
 118         }
 119
 120         return 0;
 121 }
 122
 123 static struct platform_driver simatic_ipc_led_driver = {
 124         .probe = simatic_ipc_leds_probe,
 125         .driver = {
 126                 .name = KBUILD_MODNAME,
 127         }
 128 };
 129 module_platform_driver(simatic_ipc_led_driver);
 130
 131 MODULE_LICENSE("GPL v2");
 132 MODULE_ALIAS("platform:" KBUILD_MODNAME);
 133 MODULE_AUTHOR("Henning Schild <henning.schild@siemens.com>");