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1// SPDX-License-Identifier: GPL-2.02/*3 * Siemens SIMATIC IPC driver for Watchdogs4 *5 * Copyright (c) Siemens AG, 2020-20216 *7 * Authors:8 * Gerd Haeussler <gerd.haeussler.ext@siemens.com>9 */10 11#include <linux/device.h>12#include <linux/errno.h>13#include <linux/init.h>14#include <linux/io.h>15#include <linux/ioport.h>16#include <linux/kernel.h>17#include <linux/module.h>18#include <linux/pci.h>19#include <linux/platform_data/x86/p2sb.h>20#include <linux/platform_data/x86/simatic-ipc-base.h>21#include <linux/platform_device.h>22#include <linux/sizes.h>23#include <linux/util_macros.h>24#include <linux/watchdog.h>25 26#define WD_ENABLE_IOADR 0x6227#define WD_TRIGGER_IOADR 0x6628#define GPIO_COMMUNITY0_PORT_ID 0xaf29#define PAD_CFG_DW0_GPP_A_23 0x4b830#define SAFE_EN_N_427E 0x0131#define SAFE_EN_N_227E 0x0432#define WD_ENABLED 0x0133#define WD_TRIGGERED 0x8034#define WD_MACROMODE 0x0235 36#define TIMEOUT_MIN 237#define TIMEOUT_DEF 6438#define TIMEOUT_MAX 6439 40#define GP_STATUS_REG_227E 0x404D /* IO PORT for SAFE_EN_N on 227E */41 42static bool nowayout = WATCHDOG_NOWAYOUT;43module_param(nowayout, bool, 0000);44MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="45 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");46 47static struct resource gp_status_reg_227e_res =48 DEFINE_RES_IO_NAMED(GP_STATUS_REG_227E, SZ_1, KBUILD_MODNAME);49 50static struct resource io_resource_enable =51 DEFINE_RES_IO_NAMED(WD_ENABLE_IOADR, SZ_1,52 KBUILD_MODNAME " WD_ENABLE_IOADR");53 54static struct resource io_resource_trigger =55 DEFINE_RES_IO_NAMED(WD_TRIGGER_IOADR, SZ_1,56 KBUILD_MODNAME " WD_TRIGGER_IOADR");57 58/* the actual start will be discovered with p2sb, 0 is a placeholder */59static struct resource mem_resource =60 DEFINE_RES_MEM_NAMED(0, 0, "WD_RESET_BASE_ADR");61 62static u32 wd_timeout_table[] = {2, 4, 6, 8, 16, 32, 48, 64 };63static void __iomem *wd_reset_base_addr;64 65static int wd_start(struct watchdog_device *wdd)66{67 outb(inb(WD_ENABLE_IOADR) | WD_ENABLED, WD_ENABLE_IOADR);68 return 0;69}70 71static int wd_stop(struct watchdog_device *wdd)72{73 outb(inb(WD_ENABLE_IOADR) & ~WD_ENABLED, WD_ENABLE_IOADR);74 return 0;75}76 77static int wd_ping(struct watchdog_device *wdd)78{79 inb(WD_TRIGGER_IOADR);80 return 0;81}82 83static int wd_set_timeout(struct watchdog_device *wdd, unsigned int t)84{85 int timeout_idx = find_closest(t, wd_timeout_table,86 ARRAY_SIZE(wd_timeout_table));87 88 outb((inb(WD_ENABLE_IOADR) & 0xc7) | timeout_idx << 3, WD_ENABLE_IOADR);89 wdd->timeout = wd_timeout_table[timeout_idx];90 return 0;91}92 93static const struct watchdog_info wdt_ident = {94 .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |95 WDIOF_SETTIMEOUT,96 .identity = KBUILD_MODNAME,97};98 99static const struct watchdog_ops wdt_ops = {100 .owner = THIS_MODULE,101 .start = wd_start,102 .stop = wd_stop,103 .ping = wd_ping,104 .set_timeout = wd_set_timeout,105};106 107static void wd_secondary_enable(u32 wdtmode)108{109 u16 resetbit;110 111 /* set safe_en_n so we are not just WDIOF_ALARMONLY */112 if (wdtmode == SIMATIC_IPC_DEVICE_227E) {113 /* enable SAFE_EN_N on GP_STATUS_REG_227E */114 resetbit = inb(GP_STATUS_REG_227E);115 outb(resetbit & ~SAFE_EN_N_227E, GP_STATUS_REG_227E);116 } else {117 /* enable SAFE_EN_N on PCH D1600 */118 resetbit = ioread16(wd_reset_base_addr);119 iowrite16(resetbit & ~SAFE_EN_N_427E, wd_reset_base_addr);120 }121}122 123static int wd_setup(u32 wdtmode)124{125 unsigned int bootstatus = 0;126 int timeout_idx;127 128 timeout_idx = find_closest(TIMEOUT_DEF, wd_timeout_table,129 ARRAY_SIZE(wd_timeout_table));130 131 if (inb(WD_ENABLE_IOADR) & WD_TRIGGERED)132 bootstatus |= WDIOF_CARDRESET;133 134 /* reset alarm bit, set macro mode, and set timeout */135 outb(WD_TRIGGERED | WD_MACROMODE | timeout_idx << 3, WD_ENABLE_IOADR);136 137 wd_secondary_enable(wdtmode);138 139 return bootstatus;140}141 142static struct watchdog_device wdd_data = {143 .info = &wdt_ident,144 .ops = &wdt_ops,145 .min_timeout = TIMEOUT_MIN,146 .max_timeout = TIMEOUT_MAX147};148 149static int simatic_ipc_wdt_probe(struct platform_device *pdev)150{151 struct simatic_ipc_platform *plat = pdev->dev.platform_data;152 struct device *dev = &pdev->dev;153 struct resource *res;154 int ret;155 156 switch (plat->devmode) {157 case SIMATIC_IPC_DEVICE_227E:158 res = &gp_status_reg_227e_res;159 if (!request_muxed_region(res->start, resource_size(res), res->name)) {160 dev_err(dev,161 "Unable to register IO resource at %pR\n",162 &gp_status_reg_227e_res);163 return -EBUSY;164 }165 fallthrough;166 case SIMATIC_IPC_DEVICE_427E:167 wdd_data.parent = dev;168 break;169 default:170 return -EINVAL;171 }172 173 if (!devm_request_region(dev, io_resource_enable.start,174 resource_size(&io_resource_enable),175 io_resource_enable.name)) {176 dev_err(dev,177 "Unable to register IO resource at %#x\n",178 WD_ENABLE_IOADR);179 return -EBUSY;180 }181 182 if (!devm_request_region(dev, io_resource_trigger.start,183 resource_size(&io_resource_trigger),184 io_resource_trigger.name)) {185 dev_err(dev,186 "Unable to register IO resource at %#x\n",187 WD_TRIGGER_IOADR);188 return -EBUSY;189 }190 191 if (plat->devmode == SIMATIC_IPC_DEVICE_427E) {192 res = &mem_resource;193 194 ret = p2sb_bar(NULL, 0, res);195 if (ret)196 return ret;197 198 /* do the final address calculation */199 res->start = res->start + (GPIO_COMMUNITY0_PORT_ID << 16) +200 PAD_CFG_DW0_GPP_A_23;201 res->end = res->start + SZ_4 - 1;202 203 wd_reset_base_addr = devm_ioremap_resource(dev, res);204 if (IS_ERR(wd_reset_base_addr))205 return PTR_ERR(wd_reset_base_addr);206 }207 208 wdd_data.bootstatus = wd_setup(plat->devmode);209 if (wdd_data.bootstatus)210 dev_warn(dev, "last reboot caused by watchdog reset\n");211 212 if (plat->devmode == SIMATIC_IPC_DEVICE_227E)213 release_region(gp_status_reg_227e_res.start,214 resource_size(&gp_status_reg_227e_res));215 216 watchdog_set_nowayout(&wdd_data, nowayout);217 watchdog_stop_on_reboot(&wdd_data);218 return devm_watchdog_register_device(dev, &wdd_data);219}220 221static struct platform_driver simatic_ipc_wdt_driver = {222 .probe = simatic_ipc_wdt_probe,223 .driver = {224 .name = KBUILD_MODNAME,225 },226};227 228module_platform_driver(simatic_ipc_wdt_driver);229 230MODULE_DESCRIPTION("Siemens SIMATIC IPC driver for Watchdogs");231MODULE_LICENSE("GPL v2");232MODULE_ALIAS("platform:" KBUILD_MODNAME);233MODULE_AUTHOR("Gerd Haeussler <gerd.haeussler.ext@siemens.com>");234