diff options
Diffstat (limited to 'drivers/watchdog/i6300esb.c')
| -rw-r--r-- | drivers/watchdog/i6300esb.c | 353 |
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"); |