aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/platform/x86/simatic-ipc.c
blob: b599cda5ba3c90f4f7beccb6ff8d227d5e83ffbe (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
// SPDX-License-Identifier: GPL-2.0
/*
 * Siemens SIMATIC IPC platform driver
 *
 * Copyright (c) Siemens AG, 2018-2021
 *
 * Authors:
 *  Henning Schild <henning.schild@siemens.com>
 *  Jan Kiszka <jan.kiszka@siemens.com>
 *  Gerd Haeussler <gerd.haeussler.ext@siemens.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/dmi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_data/x86/simatic-ipc.h>
#include <linux/platform_device.h>

static struct platform_device *ipc_led_platform_device;
static struct platform_device *ipc_wdt_platform_device;

static const struct dmi_system_id simatic_ipc_whitelist[] = {
	{
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "SIEMENS AG"),
		},
	},
	{}
};

static struct simatic_ipc_platform platform_data;

static struct {
	u32 station_id;
	u8 led_mode;
	u8 wdt_mode;
} device_modes[] = {
	{SIMATIC_IPC_IPC127E, SIMATIC_IPC_DEVICE_127E, SIMATIC_IPC_DEVICE_NONE},
	{SIMATIC_IPC_IPC227D, SIMATIC_IPC_DEVICE_227D, SIMATIC_IPC_DEVICE_NONE},
	{SIMATIC_IPC_IPC227E, SIMATIC_IPC_DEVICE_427E, SIMATIC_IPC_DEVICE_227E},
	{SIMATIC_IPC_IPC277E, SIMATIC_IPC_DEVICE_NONE, SIMATIC_IPC_DEVICE_227E},
	{SIMATIC_IPC_IPC427D, SIMATIC_IPC_DEVICE_427E, SIMATIC_IPC_DEVICE_NONE},
	{SIMATIC_IPC_IPC427E, SIMATIC_IPC_DEVICE_427E, SIMATIC_IPC_DEVICE_427E},
	{SIMATIC_IPC_IPC477E, SIMATIC_IPC_DEVICE_NONE, SIMATIC_IPC_DEVICE_427E},
};

static int register_platform_devices(u32 station_id)
{
	u8 ledmode = SIMATIC_IPC_DEVICE_NONE;
	u8 wdtmode = SIMATIC_IPC_DEVICE_NONE;
	int i;

	platform_data.devmode = SIMATIC_IPC_DEVICE_NONE;

	for (i = 0; i < ARRAY_SIZE(device_modes); i++) {
		if (device_modes[i].station_id == station_id) {
			ledmode = device_modes[i].led_mode;
			wdtmode = device_modes[i].wdt_mode;
			break;
		}
	}

	if (ledmode != SIMATIC_IPC_DEVICE_NONE) {
		platform_data.devmode = ledmode;
		ipc_led_platform_device =
			platform_device_register_data(NULL,
				KBUILD_MODNAME "_leds", PLATFORM_DEVID_NONE,
				&platform_data,
				sizeof(struct simatic_ipc_platform));
		if (IS_ERR(ipc_led_platform_device))
			return PTR_ERR(ipc_led_platform_device);

		pr_debug("device=%s created\n",
			 ipc_led_platform_device->name);
	}

	if (wdtmode != SIMATIC_IPC_DEVICE_NONE) {
		platform_data.devmode = wdtmode;
		ipc_wdt_platform_device =
			platform_device_register_data(NULL,
				KBUILD_MODNAME "_wdt", PLATFORM_DEVID_NONE,
				&platform_data,
				sizeof(struct simatic_ipc_platform));
		if (IS_ERR(ipc_wdt_platform_device))
			return PTR_ERR(ipc_wdt_platform_device);

		pr_debug("device=%s created\n",
			 ipc_wdt_platform_device->name);
	}

	if (ledmode == SIMATIC_IPC_DEVICE_NONE &&
	    wdtmode == SIMATIC_IPC_DEVICE_NONE) {
		pr_warn("unsupported IPC detected, station id=%08x\n",
			station_id);
		return -EINVAL;
	}

	return 0;
}

/* FIXME: this should eventually be done with generic P2SB discovery code
 * the individual drivers for watchdogs and LEDs access memory that implements
 * GPIO, but pinctrl will not come up because of missing ACPI entries
 *
 * While there is no conflict a cleaner solution would be to somehow bring up
 * pinctrl even with these ACPI entries missing, and base the drivers on pinctrl.
 * After which the following function could be dropped, together with the code
 * poking the memory.
 */
/*
 * Get membase address from PCI, used in leds and wdt module. Here we read
 * the bar0. The final address calculation is done in the appropriate modules
 */
u32 simatic_ipc_get_membase0(unsigned int p2sb)
{
	struct pci_bus *bus;
	u32 bar0 = 0;
	/*
	 * The GPIO memory is in bar0 of the hidden P2SB device.
	 * Unhide the device to have a quick look at it, before we hide it
	 * again.
	 * Also grab the pci rescan lock so that device does not get discovered
	 * and remapped while it is visible.
	 * This code is inspired by drivers/mfd/lpc_ich.c
	 */
	bus = pci_find_bus(0, 0);
	pci_lock_rescan_remove();
	pci_bus_write_config_byte(bus, p2sb, 0xE1, 0x0);
	pci_bus_read_config_dword(bus, p2sb, PCI_BASE_ADDRESS_0, &bar0);

	bar0 &= ~0xf;
	pci_bus_write_config_byte(bus, p2sb, 0xE1, 0x1);
	pci_unlock_rescan_remove();

	return bar0;
}
EXPORT_SYMBOL(simatic_ipc_get_membase0);

static int __init simatic_ipc_init_module(void)
{
	const struct dmi_system_id *match;
	u32 station_id;
	int err;

	match = dmi_first_match(simatic_ipc_whitelist);
	if (!match)
		return 0;

	err = dmi_walk(simatic_ipc_find_dmi_entry_helper, &station_id);

	if (err || station_id == SIMATIC_IPC_INVALID_STATION_ID) {
		pr_warn("DMI entry %d not found\n", SIMATIC_IPC_DMI_ENTRY_OEM);
		return 0;
	}

	return register_platform_devices(station_id);
}

static void __exit simatic_ipc_exit_module(void)
{
	platform_device_unregister(ipc_led_platform_device);
	ipc_led_platform_device = NULL;

	platform_device_unregister(ipc_wdt_platform_device);
	ipc_wdt_platform_device = NULL;
}

module_init(simatic_ipc_init_module);
module_exit(simatic_ipc_exit_module);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Gerd Haeussler <gerd.haeussler.ext@siemens.com>");
MODULE_ALIAS("dmi:*:svnSIEMENSAG:*");