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Diffstat (limited to '')
| -rw-r--r-- | drivers/watchdog/it87_wdt.c | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/drivers/watchdog/it87_wdt.c b/drivers/watchdog/it87_wdt.c new file mode 100644 index 000000000..bb1122909 --- /dev/null +++ b/drivers/watchdog/it87_wdt.c @@ -0,0 +1,354 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Watchdog Timer Driver + * for ITE IT87xx Environment Control - Low Pin Count Input / Output + * + * (c) Copyright 2007 Oliver Schuster <olivers137@aol.com> + * + * Based on softdog.c by Alan Cox, + * 83977f_wdt.c by Jose Goncalves, + * it87.c by Chris Gauthron, Jean Delvare + * + * Data-sheets: Publicly available at the ITE website + * http://www.ite.com.tw/ + * + * Support of the watchdog timers, which are available on + * IT8607, IT8620, IT8622, IT8625, IT8628, IT8655, IT8665, IT8686, + * IT8702, IT8712, IT8716, IT8718, IT8720, IT8721, IT8726, IT8728, + * IT8772, IT8783 and IT8784. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/watchdog.h> + +#define WATCHDOG_NAME "IT87 WDT" + +/* Defaults for Module Parameter */ +#define DEFAULT_TIMEOUT 60 +#define DEFAULT_TESTMODE 0 +#define DEFAULT_NOWAYOUT WATCHDOG_NOWAYOUT + +/* IO Ports */ +#define REG 0x2e +#define VAL 0x2f + +/* Logical device Numbers LDN */ +#define GPIO 0x07 + +/* Configuration Registers and Functions */ +#define LDNREG 0x07 +#define CHIPID 0x20 +#define CHIPREV 0x22 + +/* Chip Id numbers */ +#define NO_DEV_ID 0xffff +#define IT8607_ID 0x8607 +#define IT8620_ID 0x8620 +#define IT8622_ID 0x8622 +#define IT8625_ID 0x8625 +#define IT8628_ID 0x8628 +#define IT8655_ID 0x8655 +#define IT8665_ID 0x8665 +#define IT8686_ID 0x8686 +#define IT8702_ID 0x8702 +#define IT8705_ID 0x8705 +#define IT8712_ID 0x8712 +#define IT8716_ID 0x8716 +#define IT8718_ID 0x8718 +#define IT8720_ID 0x8720 +#define IT8721_ID 0x8721 +#define IT8726_ID 0x8726 /* the data sheet suggest wrongly 0x8716 */ +#define IT8728_ID 0x8728 +#define IT8772_ID 0x8772 +#define IT8783_ID 0x8783 +#define IT8784_ID 0x8784 +#define IT8786_ID 0x8786 + +/* GPIO Configuration Registers LDN=0x07 */ +#define WDTCTRL 0x71 +#define WDTCFG 0x72 +#define WDTVALLSB 0x73 +#define WDTVALMSB 0x74 + +/* GPIO Bits WDTCFG */ +#define WDT_TOV1 0x80 +#define WDT_KRST 0x40 +#define WDT_TOVE 0x20 +#define WDT_PWROK 0x10 /* not in it8721 */ +#define WDT_INT_MASK 0x0f + +static unsigned int max_units, chip_type; + +static unsigned int timeout = DEFAULT_TIMEOUT; +static int testmode = DEFAULT_TESTMODE; +static bool nowayout = DEFAULT_NOWAYOUT; + +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default=" + __MODULE_STRING(DEFAULT_TIMEOUT)); +module_param(testmode, int, 0); +MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default=" + __MODULE_STRING(DEFAULT_TESTMODE)); +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT)); + +/* Superio Chip */ + +static inline int superio_enter(void) +{ + /* + * Try to reserve REG and REG + 1 for exclusive access. + */ + if (!request_muxed_region(REG, 2, WATCHDOG_NAME)) + return -EBUSY; + + outb(0x87, REG); + outb(0x01, REG); + outb(0x55, REG); + outb(0x55, REG); + return 0; +} + +static inline void superio_exit(void) +{ + outb(0x02, REG); + outb(0x02, VAL); + release_region(REG, 2); +} + +static inline void superio_select(int ldn) +{ + outb(LDNREG, REG); + outb(ldn, VAL); +} + +static inline int superio_inb(int reg) +{ + outb(reg, REG); + return inb(VAL); +} + +static inline void superio_outb(int val, int reg) +{ + outb(reg, REG); + outb(val, VAL); +} + +static inline int superio_inw(int reg) +{ + int val; + outb(reg++, REG); + val = inb(VAL) << 8; + outb(reg, REG); + val |= inb(VAL); + return val; +} + +/* Internal function, should be called after superio_select(GPIO) */ +static void _wdt_update_timeout(unsigned int t) +{ + unsigned char cfg = WDT_KRST; + + if (testmode) + cfg = 0; + + if (t <= max_units) + cfg |= WDT_TOV1; + else + t /= 60; + + if (chip_type != IT8721_ID) + cfg |= WDT_PWROK; + + superio_outb(cfg, WDTCFG); + superio_outb(t, WDTVALLSB); + if (max_units > 255) + superio_outb(t >> 8, WDTVALMSB); +} + +static int wdt_update_timeout(unsigned int t) +{ + int ret; + + ret = superio_enter(); + if (ret) + return ret; + + superio_select(GPIO); + _wdt_update_timeout(t); + superio_exit(); + + return 0; +} + +static int wdt_round_time(int t) +{ + t += 59; + t -= t % 60; + return t; +} + +/* watchdog timer handling */ + +static int wdt_start(struct watchdog_device *wdd) +{ + return wdt_update_timeout(wdd->timeout); +} + +static int wdt_stop(struct watchdog_device *wdd) +{ + return wdt_update_timeout(0); +} + +/** + * wdt_set_timeout - set a new timeout value with watchdog ioctl + * @t: timeout value in seconds + * + * The hardware device has a 8 or 16 bit watchdog timer (depends on + * chip version) that can be configured to count seconds or minutes. + * + * Used within WDIOC_SETTIMEOUT watchdog device ioctl. + */ + +static int wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) +{ + int ret = 0; + + if (t > max_units) + t = wdt_round_time(t); + + wdd->timeout = t; + + if (watchdog_hw_running(wdd)) + ret = wdt_update_timeout(t); + + return ret; +} + +static const struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .firmware_version = 1, + .identity = WATCHDOG_NAME, +}; + +static const struct watchdog_ops wdt_ops = { + .owner = THIS_MODULE, + .start = wdt_start, + .stop = wdt_stop, + .set_timeout = wdt_set_timeout, +}; + +static struct watchdog_device wdt_dev = { + .info = &ident, + .ops = &wdt_ops, + .min_timeout = 1, +}; + +static int __init it87_wdt_init(void) +{ + u8 chip_rev; + int rc; + + rc = superio_enter(); + if (rc) + return rc; + + chip_type = superio_inw(CHIPID); + chip_rev = superio_inb(CHIPREV) & 0x0f; + superio_exit(); + + switch (chip_type) { + case IT8702_ID: + max_units = 255; + break; + case IT8712_ID: + max_units = (chip_rev < 8) ? 255 : 65535; + break; + case IT8716_ID: + case IT8726_ID: + max_units = 65535; + break; + case IT8607_ID: + case IT8620_ID: + case IT8622_ID: + case IT8625_ID: + case IT8628_ID: + case IT8655_ID: + case IT8665_ID: + case IT8686_ID: + case IT8718_ID: + case IT8720_ID: + case IT8721_ID: + case IT8728_ID: + case IT8772_ID: + case IT8783_ID: + case IT8784_ID: + case IT8786_ID: + max_units = 65535; + break; + case IT8705_ID: + pr_err("Unsupported Chip found, Chip %04x Revision %02x\n", + chip_type, chip_rev); + return -ENODEV; + case NO_DEV_ID: + pr_err("no device\n"); + return -ENODEV; + default: + pr_err("Unknown Chip found, Chip %04x Revision %04x\n", + chip_type, chip_rev); + return -ENODEV; + } + + rc = superio_enter(); + if (rc) + return rc; + + superio_select(GPIO); + superio_outb(WDT_TOV1, WDTCFG); + superio_outb(0x00, WDTCTRL); + superio_exit(); + + if (timeout < 1 || timeout > max_units * 60) { + timeout = DEFAULT_TIMEOUT; + pr_warn("Timeout value out of range, use default %d sec\n", + DEFAULT_TIMEOUT); + } + + if (timeout > max_units) + timeout = wdt_round_time(timeout); + + wdt_dev.timeout = timeout; + wdt_dev.max_timeout = max_units * 60; + + watchdog_stop_on_reboot(&wdt_dev); + rc = watchdog_register_device(&wdt_dev); + if (rc) { + pr_err("Cannot register watchdog device (err=%d)\n", rc); + return rc; + } + + pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d)\n", + chip_type, chip_rev, timeout, nowayout, testmode); + + return 0; +} + +static void __exit it87_wdt_exit(void) +{ + watchdog_unregister_device(&wdt_dev); +} + +module_init(it87_wdt_init); +module_exit(it87_wdt_exit); + +MODULE_AUTHOR("Oliver Schuster"); +MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O"); +MODULE_LICENSE("GPL"); |