blob: cdc1a2e1518051c212e64214086f071ac3bde61e [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Siemens SIMATIC IPC driver for Watchdogs
*
* Copyright (c) Siemens AG, 2020-2021
*
* Authors:
* Gerd Haeussler <gerd.haeussler.ext@siemens.com>
*/
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_data/x86/p2sb.h>
#include <linux/platform_data/x86/simatic-ipc-base.h>
#include <linux/platform_device.h>
#include <linux/sizes.h>
#include <linux/util_macros.h>
#include <linux/watchdog.h>
#define WD_ENABLE_IOADR 0x62
#define WD_TRIGGER_IOADR 0x66
#define GPIO_COMMUNITY0_PORT_ID 0xaf
#define PAD_CFG_DW0_GPP_A_23 0x4b8
#define SAFE_EN_N_427E 0x01
#define SAFE_EN_N_227E 0x04
#define WD_ENABLED 0x01
#define WD_TRIGGERED 0x80
#define WD_MACROMODE 0x02
#define TIMEOUT_MIN 2
#define TIMEOUT_DEF 64
#define TIMEOUT_MAX 64
#define GP_STATUS_REG_227E 0x404D /* IO PORT for SAFE_EN_N on 227E */
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0000);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static struct resource gp_status_reg_227e_res =
DEFINE_RES_IO_NAMED(GP_STATUS_REG_227E, SZ_1, KBUILD_MODNAME);
static struct resource io_resource_enable =
DEFINE_RES_IO_NAMED(WD_ENABLE_IOADR, SZ_1,
KBUILD_MODNAME " WD_ENABLE_IOADR");
static struct resource io_resource_trigger =
DEFINE_RES_IO_NAMED(WD_TRIGGER_IOADR, SZ_1,
KBUILD_MODNAME " WD_TRIGGER_IOADR");
/* the actual start will be discovered with p2sb, 0 is a placeholder */
static struct resource mem_resource =
DEFINE_RES_MEM_NAMED(0, 0, "WD_RESET_BASE_ADR");
static u32 wd_timeout_table[] = {2, 4, 6, 8, 16, 32, 48, 64 };
static void __iomem *wd_reset_base_addr;
static int wd_start(struct watchdog_device *wdd)
{
outb(inb(WD_ENABLE_IOADR) | WD_ENABLED, WD_ENABLE_IOADR);
return 0;
}
static int wd_stop(struct watchdog_device *wdd)
{
outb(inb(WD_ENABLE_IOADR) & ~WD_ENABLED, WD_ENABLE_IOADR);
return 0;
}
static int wd_ping(struct watchdog_device *wdd)
{
inb(WD_TRIGGER_IOADR);
return 0;
}
static int wd_set_timeout(struct watchdog_device *wdd, unsigned int t)
{
int timeout_idx = find_closest(t, wd_timeout_table,
ARRAY_SIZE(wd_timeout_table));
outb((inb(WD_ENABLE_IOADR) & 0xc7) | timeout_idx << 3, WD_ENABLE_IOADR);
wdd->timeout = wd_timeout_table[timeout_idx];
return 0;
}
static const struct watchdog_info wdt_ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT,
.identity = KBUILD_MODNAME,
};
static const struct watchdog_ops wdt_ops = {
.owner = THIS_MODULE,
.start = wd_start,
.stop = wd_stop,
.ping = wd_ping,
.set_timeout = wd_set_timeout,
};
static void wd_secondary_enable(u32 wdtmode)
{
u16 resetbit;
/* set safe_en_n so we are not just WDIOF_ALARMONLY */
if (wdtmode == SIMATIC_IPC_DEVICE_227E) {
/* enable SAFE_EN_N on GP_STATUS_REG_227E */
resetbit = inb(GP_STATUS_REG_227E);
outb(resetbit & ~SAFE_EN_N_227E, GP_STATUS_REG_227E);
} else {
/* enable SAFE_EN_N on PCH D1600 */
resetbit = ioread16(wd_reset_base_addr);
iowrite16(resetbit & ~SAFE_EN_N_427E, wd_reset_base_addr);
}
}
static int wd_setup(u32 wdtmode)
{
unsigned int bootstatus = 0;
int timeout_idx;
timeout_idx = find_closest(TIMEOUT_DEF, wd_timeout_table,
ARRAY_SIZE(wd_timeout_table));
if (inb(WD_ENABLE_IOADR) & WD_TRIGGERED)
bootstatus |= WDIOF_CARDRESET;
/* reset alarm bit, set macro mode, and set timeout */
outb(WD_TRIGGERED | WD_MACROMODE | timeout_idx << 3, WD_ENABLE_IOADR);
wd_secondary_enable(wdtmode);
return bootstatus;
}
static struct watchdog_device wdd_data = {
.info = &wdt_ident,
.ops = &wdt_ops,
.min_timeout = TIMEOUT_MIN,
.max_timeout = TIMEOUT_MAX
};
static int simatic_ipc_wdt_probe(struct platform_device *pdev)
{
struct simatic_ipc_platform *plat = pdev->dev.platform_data;
struct device *dev = &pdev->dev;
struct resource *res;
int ret;
switch (plat->devmode) {
case SIMATIC_IPC_DEVICE_227E:
res = &gp_status_reg_227e_res;
if (!request_muxed_region(res->start, resource_size(res), res->name)) {
dev_err(dev,
"Unable to register IO resource at %pR\n",
&gp_status_reg_227e_res);
return -EBUSY;
}
fallthrough;
case SIMATIC_IPC_DEVICE_427E:
wdd_data.parent = dev;
break;
default:
return -EINVAL;
}
if (!devm_request_region(dev, io_resource_enable.start,
resource_size(&io_resource_enable),
io_resource_enable.name)) {
dev_err(dev,
"Unable to register IO resource at %#x\n",
WD_ENABLE_IOADR);
return -EBUSY;
}
if (!devm_request_region(dev, io_resource_trigger.start,
resource_size(&io_resource_trigger),
io_resource_trigger.name)) {
dev_err(dev,
"Unable to register IO resource at %#x\n",
WD_TRIGGER_IOADR);
return -EBUSY;
}
if (plat->devmode == SIMATIC_IPC_DEVICE_427E) {
res = &mem_resource;
ret = p2sb_bar(NULL, 0, res);
if (ret)
return ret;
/* do the final address calculation */
res->start = res->start + (GPIO_COMMUNITY0_PORT_ID << 16) +
PAD_CFG_DW0_GPP_A_23;
res->end = res->start + SZ_4 - 1;
wd_reset_base_addr = devm_ioremap_resource(dev, res);
if (IS_ERR(wd_reset_base_addr))
return PTR_ERR(wd_reset_base_addr);
}
wdd_data.bootstatus = wd_setup(plat->devmode);
if (wdd_data.bootstatus)
dev_warn(dev, "last reboot caused by watchdog reset\n");
if (plat->devmode == SIMATIC_IPC_DEVICE_227E)
release_region(gp_status_reg_227e_res.start,
resource_size(&gp_status_reg_227e_res));
watchdog_set_nowayout(&wdd_data, nowayout);
watchdog_stop_on_reboot(&wdd_data);
return devm_watchdog_register_device(dev, &wdd_data);
}
static struct platform_driver simatic_ipc_wdt_driver = {
.probe = simatic_ipc_wdt_probe,
.driver = {
.name = KBUILD_MODNAME,
},
};
module_platform_driver(simatic_ipc_wdt_driver);
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" KBUILD_MODNAME);
MODULE_AUTHOR("Gerd Haeussler <gerd.haeussler.ext@siemens.com>");