linux/linux-5.18.11/drivers/platform/x86/simatic-ipc.c

177 lines
5.0 KiB
C

// 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:*");