diff options
Diffstat (limited to 'drivers/watchdog/simatic-ipc-wdt.c')
| -rw-r--r-- | drivers/watchdog/simatic-ipc-wdt.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/watchdog/simatic-ipc-wdt.c b/drivers/watchdog/simatic-ipc-wdt.c new file mode 100644 index 0000000000..cdc1a2e151 --- /dev/null +++ b/drivers/watchdog/simatic-ipc-wdt.c @@ -0,0 +1,232 @@ +// 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>"); |