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
25struct simatic_ipc_led {
26 unsigned int value; /* mask for io */
27 char *name;
28 struct led_classdev cdev;
29};
30
31static 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
41static struct resource simatic_ipc_led_io_res =
42 DEFINE_RES_IO_NAMED(SIMATIC_IPC_LED_PORT_BASE, SZ_2, KBUILD_MODNAME);
43
44static DEFINE_SPINLOCK(reg_lock);
45
46static 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
51static 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(value: val | led->value, SIMATIC_IPC_LED_PORT_BASE);
63 else
64 outw(value: val & ~led->value, SIMATIC_IPC_LED_PORT_BASE);
65
66 spin_unlock_irqrestore(lock: &reg_lock, flags);
67}
68
69static 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
76static 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(parent: dev, led_cdev: cdev);
115 if (err < 0)
116 return err;
117 ipcled++;
118 }
119
120 return 0;
121}
122
123static struct platform_driver simatic_ipc_led_driver = {
124 .probe = simatic_ipc_leds_probe,
125 .driver = {
126 .name = KBUILD_MODNAME,
127 }
128};
129module_platform_driver(simatic_ipc_led_driver);
130
131MODULE_LICENSE("GPL v2");
132MODULE_ALIAS("platform:" KBUILD_MODNAME);
133MODULE_AUTHOR("Henning Schild <henning.schild@siemens.com>");
134

source code of linux/drivers/leds/simple/simatic-ipc-leds.c