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Diffstat (limited to 'drivers/watchdog/it87_wdt.c')
-rw-r--r--drivers/watchdog/it87_wdt.c354
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 0000000000..bb11229093
--- /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");