--- /dev/null
+/*
+ * VIA Chipset Watchdog Driver
+ *
+ * Copyright (C) 2011 Sigfox
+ * License terms: GNU General Public License (GPL) version 2
+ * Author: Marc Vertes <marc.vertes@sigfox.com>
+ * Based on a preliminary version from Harald Welte <HaraldWelte@viatech.com>
+ * Timer code by Wim Van Sebroeck <wim@iguana.be>
+ *
+ * Caveat: PnP must be enabled in BIOS to allow full access to watchdog
+ * control registers. If not, the watchdog must be configured in BIOS manually.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/timer.h>
+#include <linux/watchdog.h>
+
+/* Configuration registers relative to the pci device */
+#define VIA_WDT_MMIO_BASE 0xe8 /* MMIO region base address */
+#define VIA_WDT_CONF 0xec /* watchdog enable state */
+
+/* Relevant bits for the VIA_WDT_CONF register */
+#define VIA_WDT_CONF_ENABLE 0x01 /* 1: enable watchdog */
+#define VIA_WDT_CONF_MMIO 0x02 /* 1: enable watchdog MMIO */
+
+/*
+ * The MMIO region contains the watchog control register and the
+ * hardware timer counter.
+ */
+#define VIA_WDT_MMIO_LEN 8 /* MMIO region length in bytes */
+#define VIA_WDT_CTL 0 /* MMIO addr+0: state/control reg. */
+#define VIA_WDT_COUNT 4 /* MMIO addr+4: timer counter reg. */
+
+/* Bits for the VIA_WDT_CTL register */
+#define VIA_WDT_RUNNING 0x01 /* 0: stop, 1: running */
+#define VIA_WDT_FIRED 0x02 /* 1: restarted by expired watchdog */
+#define VIA_WDT_PWROFF 0x04 /* 0: reset, 1: poweroff */
+#define VIA_WDT_DISABLED 0x08 /* 1: timer is disabled */
+#define VIA_WDT_TRIGGER 0x80 /* 1: start a new countdown */
+
+/* Hardware heartbeat in seconds */
+#define WDT_HW_HEARTBEAT 1
+
+/* Timer heartbeat (500ms) */
+#define WDT_HEARTBEAT (HZ/2) /* should be <= ((WDT_HW_HEARTBEAT*HZ)/2) */
+
+/* User space timeout in seconds */
+#define WDT_TIMEOUT_MAX 1023 /* approx. 17 min. */
+#define WDT_TIMEOUT 60
+static int timeout = WDT_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, between 1 and 1023 "
+ "(default = " __MODULE_STRING(WDT_TIMEOUT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+ "(default = " __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static struct watchdog_device wdt_dev;
+static struct resource wdt_res;
+static void __iomem *wdt_mem;
+static unsigned int mmio;
+static void wdt_timer_tick(unsigned long data);
+static DEFINE_TIMER(timer, wdt_timer_tick, 0, 0);
+ /* The timer that pings the watchdog */
+static unsigned long next_heartbeat; /* the next_heartbeat for the timer */
+
+static inline void wdt_reset(void)
+{
+ unsigned int ctl = readl(wdt_mem);
+
+ writel(ctl | VIA_WDT_TRIGGER, wdt_mem);
+}
+
+/*
+ * Timer tick: the timer will make sure that the watchdog timer hardware
+ * is being reset in time. The conditions to do this are:
+ * 1) the watchog timer has been started and /dev/watchdog is open
+ * and there is still time left before userspace should send the
+ * next heartbeat/ping. (note: the internal heartbeat is much smaller
+ * then the external/userspace heartbeat).
+ * 2) the watchdog timer has been stopped by userspace.
+ */
+static void wdt_timer_tick(unsigned long data)
+{
+ if (time_before(jiffies, next_heartbeat) ||
+ (!watchdog_active(&wdt_dev))) {
+ wdt_reset();
+ mod_timer(&timer, jiffies + WDT_HEARTBEAT);
+ } else
+ pr_crit("I will reboot your machine !\n");
+}
+
+static int wdt_ping(struct watchdog_device *wdd)
+{
+ /* calculate when the next userspace timeout will be */
+ next_heartbeat = jiffies + wdd->timeout * HZ;
+ return 0;
+}
+
+static int wdt_start(struct watchdog_device *wdd)
+{
+ unsigned int ctl = readl(wdt_mem);
+
+ writel(wdd->timeout, wdt_mem + VIA_WDT_COUNT);
+ writel(ctl | VIA_WDT_RUNNING | VIA_WDT_TRIGGER, wdt_mem);
+ wdt_ping(wdd);
+ mod_timer(&timer, jiffies + WDT_HEARTBEAT);
+ return 0;
+}
+
+static int wdt_stop(struct watchdog_device *wdd)
+{
+ unsigned int ctl = readl(wdt_mem);
+
+ writel(ctl & ~VIA_WDT_RUNNING, wdt_mem);
+ return 0;
+}
+
+static int wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int new_timeout)
+{
+ writel(new_timeout, wdt_mem + VIA_WDT_COUNT);
+ wdd->timeout = new_timeout;
+ return 0;
+}
+
+static const struct watchdog_info wdt_info = {
+ .identity = "VIA watchdog",
+ .options = WDIOF_CARDRESET |
+ WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE |
+ WDIOF_KEEPALIVEPING,
+};
+
+static const struct watchdog_ops wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = wdt_start,
+ .stop = wdt_stop,
+ .ping = wdt_ping,
+ .set_timeout = wdt_set_timeout,
+};
+
+static struct watchdog_device wdt_dev = {
+ .info = &wdt_info,
+ .ops = &wdt_ops,
+ .min_timeout = 1,
+ .max_timeout = WDT_TIMEOUT_MAX,
+};
+
+static int wdt_probe(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ unsigned char conf;
+ int ret = -ENODEV;
+
+ if (pci_enable_device(pdev)) {
+ dev_err(&pdev->dev, "cannot enable PCI device\n");
+ return -ENODEV;
+ }
+
+ /*
+ * Allocate a MMIO region which contains watchdog control register
+ * and counter, then configure the watchdog to use this region.
+ * This is possible only if PnP is properly enabled in BIOS.
+ * If not, the watchdog must be configured in BIOS manually.
+ */
+ if (allocate_resource(&iomem_resource, &wdt_res, VIA_WDT_MMIO_LEN,
+ 0xf0000000, 0xffffff00, 0xff, NULL, NULL)) {
+ dev_err(&pdev->dev, "MMIO allocation failed\n");
+ goto err_out_disable_device;
+ }
+
+ pci_write_config_dword(pdev, VIA_WDT_MMIO_BASE, wdt_res.start);
+ pci_read_config_byte(pdev, VIA_WDT_CONF, &conf);
+ conf |= VIA_WDT_CONF_ENABLE | VIA_WDT_CONF_MMIO;
+ pci_write_config_byte(pdev, VIA_WDT_CONF, conf);
+
+ pci_read_config_dword(pdev, VIA_WDT_MMIO_BASE, &mmio);
+ if (mmio) {
+ dev_info(&pdev->dev, "VIA Chipset watchdog MMIO: %x\n", mmio);
+ } else {
+ dev_err(&pdev->dev, "MMIO setting failed. Check BIOS.\n");
+ goto err_out_resource;
+ }
+
+ if (!request_mem_region(mmio, VIA_WDT_MMIO_LEN, "via_wdt")) {
+ dev_err(&pdev->dev, "MMIO region busy\n");
+ goto err_out_resource;
+ }
+
+ wdt_mem = ioremap(mmio, VIA_WDT_MMIO_LEN);
+ if (wdt_mem == NULL) {
+ dev_err(&pdev->dev, "cannot remap VIA wdt MMIO registers\n");
+ goto err_out_release;
+ }
+
+ if (timeout < 1 || timeout > WDT_TIMEOUT_MAX)
+ timeout = WDT_TIMEOUT;
+
+ wdt_dev.timeout = timeout;
+ watchdog_set_nowayout(&wdt_dev, nowayout);
+ if (readl(wdt_mem) & VIA_WDT_FIRED)
+ wdt_dev.bootstatus |= WDIOF_CARDRESET;
+
+ ret = watchdog_register_device(&wdt_dev);
+ if (ret)
+ goto err_out_iounmap;
+
+ /* start triggering, in case of watchdog already enabled by BIOS */
+ mod_timer(&timer, jiffies + WDT_HEARTBEAT);
+ return 0;
+
+err_out_iounmap:
+ iounmap(wdt_mem);
+err_out_release:
+ release_mem_region(mmio, VIA_WDT_MMIO_LEN);
+err_out_resource:
+ release_resource(&wdt_res);
+err_out_disable_device:
+ pci_disable_device(pdev);
+ return ret;
+}
+
+static void wdt_remove(struct pci_dev *pdev)
+{
+ watchdog_unregister_device(&wdt_dev);
+ del_timer_sync(&timer);
+ iounmap(wdt_mem);
+ release_mem_region(mmio, VIA_WDT_MMIO_LEN);
+ release_resource(&wdt_res);
+ pci_disable_device(pdev);
+}
+
+static const struct pci_device_id wdt_pci_table[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_CX700) },
+ { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX800) },
+ { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
+ { 0 }
+};
+
+static struct pci_driver wdt_driver = {
+ .name = "via_wdt",
+ .id_table = wdt_pci_table,
+ .probe = wdt_probe,
+ .remove = wdt_remove,
+};
+
+module_pci_driver(wdt_driver);
+
+MODULE_AUTHOR("Marc Vertes");
+MODULE_DESCRIPTION("Driver for watchdog timer on VIA chipset");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff