summaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/i6300esb.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/watchdog/i6300esb.c353
1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/watchdog/i6300esb.c b/drivers/watchdog/i6300esb.c
new file mode 100644
index 000000000..a30835f54
--- /dev/null
+++ b/drivers/watchdog/i6300esb.c
@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * i6300esb: Watchdog timer driver for Intel 6300ESB chipset
+ *
+ * (c) Copyright 2004 Google Inc.
+ * (c) Copyright 2005 David Härdeman <david@2gen.com>
+ *
+ * based on i810-tco.c which is in turn based on softdog.c
+ *
+ * The timer is implemented in the following I/O controller hubs:
+ * (See the intel documentation on http://developer.intel.com.)
+ * 6300ESB chip : document number 300641-004
+ *
+ * 2004YYZZ Ross Biro
+ * Initial version 0.01
+ * 2004YYZZ Ross Biro
+ * Version 0.02
+ * 20050210 David Härdeman <david@2gen.com>
+ * Ported driver to kernel 2.6
+ * 20171016 Radu Rendec <rrendec@arista.com>
+ * Change driver to use the watchdog subsystem
+ * Add support for multiple 6300ESB devices
+ */
+
+/*
+ * Includes, defines, variables, module parameters, ...
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+/* Module and version information */
+#define ESB_MODULE_NAME "i6300ESB timer"
+
+/* PCI configuration registers */
+#define ESB_CONFIG_REG 0x60 /* Config register */
+#define ESB_LOCK_REG 0x68 /* WDT lock register */
+
+/* Memory mapped registers */
+#define ESB_TIMER1_REG(w) ((w)->base + 0x00)/* Timer1 value after each reset */
+#define ESB_TIMER2_REG(w) ((w)->base + 0x04)/* Timer2 value after each reset */
+#define ESB_GINTSR_REG(w) ((w)->base + 0x08)/* General Interrupt Status Reg */
+#define ESB_RELOAD_REG(w) ((w)->base + 0x0c)/* Reload register */
+
+/* Lock register bits */
+#define ESB_WDT_FUNC (0x01 << 2) /* Watchdog functionality */
+#define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */
+#define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */
+
+/* Config register bits */
+#define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */
+#define ESB_WDT_FREQ (0x01 << 2) /* Decrement frequency */
+#define ESB_WDT_INTTYPE (0x03 << 0) /* Interrupt type on timer1 timeout */
+
+/* Reload register bits */
+#define ESB_WDT_TIMEOUT (0x01 << 9) /* Watchdog timed out */
+#define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */
+
+/* Magic constants */
+#define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
+#define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
+
+/* module parameters */
+/* 30 sec default heartbeat (1 < heartbeat < 2*1023) */
+#define ESB_HEARTBEAT_MIN 1
+#define ESB_HEARTBEAT_MAX 2046
+#define ESB_HEARTBEAT_DEFAULT 30
+#define ESB_HEARTBEAT_RANGE __MODULE_STRING(ESB_HEARTBEAT_MIN) \
+ "<heartbeat<" __MODULE_STRING(ESB_HEARTBEAT_MAX)
+static int heartbeat; /* in seconds */
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat,
+ "Watchdog heartbeat in seconds. (" ESB_HEARTBEAT_RANGE
+ ", default=" __MODULE_STRING(ESB_HEARTBEAT_DEFAULT) ")");
+
+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) ")");
+
+/* internal variables */
+struct esb_dev {
+ struct watchdog_device wdd;
+ void __iomem *base;
+ struct pci_dev *pdev;
+};
+
+#define to_esb_dev(wptr) container_of(wptr, struct esb_dev, wdd)
+
+/*
+ * Some i6300ESB specific functions
+ */
+
+/*
+ * Prepare for reloading the timer by unlocking the proper registers.
+ * This is performed by first writing 0x80 followed by 0x86 to the
+ * reload register. After this the appropriate registers can be written
+ * to once before they need to be unlocked again.
+ */
+static inline void esb_unlock_registers(struct esb_dev *edev)
+{
+ writew(ESB_UNLOCK1, ESB_RELOAD_REG(edev));
+ writew(ESB_UNLOCK2, ESB_RELOAD_REG(edev));
+}
+
+static int esb_timer_start(struct watchdog_device *wdd)
+{
+ struct esb_dev *edev = to_esb_dev(wdd);
+ int _wdd_nowayout = test_bit(WDOG_NO_WAY_OUT, &wdd->status);
+ u8 val;
+
+ esb_unlock_registers(edev);
+ writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
+ /* Enable or Enable + Lock? */
+ val = ESB_WDT_ENABLE | (_wdd_nowayout ? ESB_WDT_LOCK : 0x00);
+ pci_write_config_byte(edev->pdev, ESB_LOCK_REG, val);
+ return 0;
+}
+
+static int esb_timer_stop(struct watchdog_device *wdd)
+{
+ struct esb_dev *edev = to_esb_dev(wdd);
+ u8 val;
+
+ /* First, reset timers as suggested by the docs */
+ esb_unlock_registers(edev);
+ writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
+ /* Then disable the WDT */
+ pci_write_config_byte(edev->pdev, ESB_LOCK_REG, 0x0);
+ pci_read_config_byte(edev->pdev, ESB_LOCK_REG, &val);
+
+ /* Returns 0 if the timer was disabled, non-zero otherwise */
+ return val & ESB_WDT_ENABLE;
+}
+
+static int esb_timer_keepalive(struct watchdog_device *wdd)
+{
+ struct esb_dev *edev = to_esb_dev(wdd);
+
+ esb_unlock_registers(edev);
+ writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
+ /* FIXME: Do we need to flush anything here? */
+ return 0;
+}
+
+static int esb_timer_set_heartbeat(struct watchdog_device *wdd,
+ unsigned int time)
+{
+ struct esb_dev *edev = to_esb_dev(wdd);
+ u32 val;
+
+ /* We shift by 9, so if we are passed a value of 1 sec,
+ * val will be 1 << 9 = 512, then write that to two
+ * timers => 2 * 512 = 1024 (which is decremented at 1KHz)
+ */
+ val = time << 9;
+
+ /* Write timer 1 */
+ esb_unlock_registers(edev);
+ writel(val, ESB_TIMER1_REG(edev));
+
+ /* Write timer 2 */
+ esb_unlock_registers(edev);
+ writel(val, ESB_TIMER2_REG(edev));
+
+ /* Reload */
+ esb_unlock_registers(edev);
+ writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
+
+ /* FIXME: Do we need to flush everything out? */
+
+ /* Done */
+ wdd->timeout = time;
+ return 0;
+}
+
+/*
+ * Watchdog Subsystem Interfaces
+ */
+
+static struct watchdog_info esb_info = {
+ .identity = ESB_MODULE_NAME,
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops esb_ops = {
+ .owner = THIS_MODULE,
+ .start = esb_timer_start,
+ .stop = esb_timer_stop,
+ .set_timeout = esb_timer_set_heartbeat,
+ .ping = esb_timer_keepalive,
+};
+
+/*
+ * Data for PCI driver interface
+ */
+static const struct pci_device_id esb_pci_tbl[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_9), },
+ { 0, }, /* End of list */
+};
+MODULE_DEVICE_TABLE(pci, esb_pci_tbl);
+
+/*
+ * Init & exit routines
+ */
+
+static unsigned char esb_getdevice(struct esb_dev *edev)
+{
+ if (pci_enable_device(edev->pdev)) {
+ dev_err(&edev->pdev->dev, "failed to enable device\n");
+ goto err_devput;
+ }
+
+ if (pci_request_region(edev->pdev, 0, ESB_MODULE_NAME)) {
+ dev_err(&edev->pdev->dev, "failed to request region\n");
+ goto err_disable;
+ }
+
+ edev->base = pci_ioremap_bar(edev->pdev, 0);
+ if (edev->base == NULL) {
+ /* Something's wrong here, BASEADDR has to be set */
+ dev_err(&edev->pdev->dev, "failed to get BASEADDR\n");
+ goto err_release;
+ }
+
+ /* Done */
+ dev_set_drvdata(&edev->pdev->dev, edev);
+ return 1;
+
+err_release:
+ pci_release_region(edev->pdev, 0);
+err_disable:
+ pci_disable_device(edev->pdev);
+err_devput:
+ return 0;
+}
+
+static void esb_initdevice(struct esb_dev *edev)
+{
+ u8 val1;
+ u16 val2;
+
+ /*
+ * Config register:
+ * Bit 5 : 0 = Enable WDT_OUTPUT
+ * Bit 2 : 0 = set the timer frequency to the PCI clock
+ * divided by 2^15 (approx 1KHz).
+ * Bits 1:0 : 11 = WDT_INT_TYPE Disabled.
+ * The watchdog has two timers, it can be setup so that the
+ * expiry of timer1 results in an interrupt and the expiry of
+ * timer2 results in a reboot. We set it to not generate
+ * any interrupts as there is not much we can do with it
+ * right now.
+ */
+ pci_write_config_word(edev->pdev, ESB_CONFIG_REG, 0x0003);
+
+ /* Check that the WDT isn't already locked */
+ pci_read_config_byte(edev->pdev, ESB_LOCK_REG, &val1);
+ if (val1 & ESB_WDT_LOCK)
+ dev_warn(&edev->pdev->dev, "nowayout already set\n");
+
+ /* Set the timer to watchdog mode and disable it for now */
+ pci_write_config_byte(edev->pdev, ESB_LOCK_REG, 0x00);
+
+ /* Check if the watchdog was previously triggered */
+ esb_unlock_registers(edev);
+ val2 = readw(ESB_RELOAD_REG(edev));
+ if (val2 & ESB_WDT_TIMEOUT)
+ edev->wdd.bootstatus = WDIOF_CARDRESET;
+
+ /* Reset WDT_TIMEOUT flag and timers */
+ esb_unlock_registers(edev);
+ writew((ESB_WDT_TIMEOUT | ESB_WDT_RELOAD), ESB_RELOAD_REG(edev));
+
+ /* And set the correct timeout value */
+ esb_timer_set_heartbeat(&edev->wdd, edev->wdd.timeout);
+}
+
+static int esb_probe(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ struct esb_dev *edev;
+ int ret;
+
+ edev = devm_kzalloc(&pdev->dev, sizeof(*edev), GFP_KERNEL);
+ if (!edev)
+ return -ENOMEM;
+
+ /* Check whether or not the hardware watchdog is there */
+ edev->pdev = pdev;
+ if (!esb_getdevice(edev))
+ return -ENODEV;
+
+ /* Initialize the watchdog and make sure it does not run */
+ edev->wdd.info = &esb_info;
+ edev->wdd.ops = &esb_ops;
+ edev->wdd.min_timeout = ESB_HEARTBEAT_MIN;
+ edev->wdd.max_timeout = ESB_HEARTBEAT_MAX;
+ edev->wdd.timeout = ESB_HEARTBEAT_DEFAULT;
+ watchdog_init_timeout(&edev->wdd, heartbeat, NULL);
+ watchdog_set_nowayout(&edev->wdd, nowayout);
+ watchdog_stop_on_reboot(&edev->wdd);
+ watchdog_stop_on_unregister(&edev->wdd);
+ esb_initdevice(edev);
+
+ /* Register the watchdog so that userspace has access to it */
+ ret = watchdog_register_device(&edev->wdd);
+ if (ret != 0)
+ goto err_unmap;
+ dev_info(&pdev->dev,
+ "initialized. heartbeat=%d sec (nowayout=%d)\n",
+ edev->wdd.timeout, nowayout);
+ return 0;
+
+err_unmap:
+ iounmap(edev->base);
+ pci_release_region(edev->pdev, 0);
+ pci_disable_device(edev->pdev);
+ return ret;
+}
+
+static void esb_remove(struct pci_dev *pdev)
+{
+ struct esb_dev *edev = dev_get_drvdata(&pdev->dev);
+
+ watchdog_unregister_device(&edev->wdd);
+ iounmap(edev->base);
+ pci_release_region(edev->pdev, 0);
+ pci_disable_device(edev->pdev);
+}
+
+static struct pci_driver esb_driver = {
+ .name = ESB_MODULE_NAME,
+ .id_table = esb_pci_tbl,
+ .probe = esb_probe,
+ .remove = esb_remove,
+};
+
+module_pci_driver(esb_driver);
+
+MODULE_AUTHOR("Ross Biro and David Härdeman");
+MODULE_DESCRIPTION("Watchdog driver for Intel 6300ESB chipsets");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 08:08:21 +0000