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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /drivers/watchdog/i6300esb.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'drivers/watchdog/i6300esb.c')
-rw-r--r-- | drivers/watchdog/i6300esb.c | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/drivers/watchdog/i6300esb.c b/drivers/watchdog/i6300esb.c new file mode 100644 index 00000000..738032a3 --- /dev/null +++ b/drivers/watchdog/i6300esb.c @@ -0,0 +1,512 @@ +/* + * i6300esb: Watchdog timer driver for Intel 6300ESB chipset + * + * (c) Copyright 2004 Google Inc. + * (c) Copyright 2005 David Härdeman <david@2gen.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * 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 + */ + +/* + * Includes, defines, variables, module parameters, ... + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#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/init.h> +#include <linux/pci.h> +#include <linux/ioport.h> +#include <linux/uaccess.h> +#include <linux/io.h> + +/* Module and version information */ +#define ESB_VERSION "0.05" +#define ESB_MODULE_NAME "i6300ESB timer" +#define ESB_DRIVER_NAME ESB_MODULE_NAME ", v" ESB_VERSION + +/* 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 (BASEADDR + 0x00)/* Timer1 value after each reset */ +#define ESB_TIMER2_REG (BASEADDR + 0x04)/* Timer2 value after each reset */ +#define ESB_GINTSR_REG (BASEADDR + 0x08)/* General Interrupt Status Register */ +#define ESB_RELOAD_REG (BASEADDR + 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 */ + +/* internal variables */ +static void __iomem *BASEADDR; +static DEFINE_SPINLOCK(esb_lock); /* Guards the hardware */ +static unsigned long timer_alive; +static struct pci_dev *esb_pci; +static unsigned short triggered; /* The status of the watchdog upon boot */ +static char esb_expect_close; + +/* We can only use 1 card due to the /dev/watchdog restriction */ +static int cards_found; + +/* module parameters */ +/* 30 sec default heartbeat (1 < heartbeat < 2*1023) */ +#define WATCHDOG_HEARTBEAT 30 +static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */ +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, + "Watchdog heartbeat in seconds. (1<heartbeat<2046, default=" + __MODULE_STRING(WATCHDOG_HEARTBEAT) ")"); + +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) ")"); + +/* + * 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(void) +{ + writew(ESB_UNLOCK1, ESB_RELOAD_REG); + writew(ESB_UNLOCK2, ESB_RELOAD_REG); +} + +static int esb_timer_start(void) +{ + u8 val; + + spin_lock(&esb_lock); + esb_unlock_registers(); + writew(ESB_WDT_RELOAD, ESB_RELOAD_REG); + /* Enable or Enable + Lock? */ + val = ESB_WDT_ENABLE | (nowayout ? ESB_WDT_LOCK : 0x00); + pci_write_config_byte(esb_pci, ESB_LOCK_REG, val); + spin_unlock(&esb_lock); + return 0; +} + +static int esb_timer_stop(void) +{ + u8 val; + + spin_lock(&esb_lock); + /* First, reset timers as suggested by the docs */ + esb_unlock_registers(); + writew(ESB_WDT_RELOAD, ESB_RELOAD_REG); + /* Then disable the WDT */ + pci_write_config_byte(esb_pci, ESB_LOCK_REG, 0x0); + pci_read_config_byte(esb_pci, ESB_LOCK_REG, &val); + spin_unlock(&esb_lock); + + /* Returns 0 if the timer was disabled, non-zero otherwise */ + return val & ESB_WDT_ENABLE; +} + +static void esb_timer_keepalive(void) +{ + spin_lock(&esb_lock); + esb_unlock_registers(); + writew(ESB_WDT_RELOAD, ESB_RELOAD_REG); + /* FIXME: Do we need to flush anything here? */ + spin_unlock(&esb_lock); +} + +static int esb_timer_set_heartbeat(int time) +{ + u32 val; + + if (time < 0x1 || time > (2 * 0x03ff)) + return -EINVAL; + + spin_lock(&esb_lock); + + /* 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(); + writel(val, ESB_TIMER1_REG); + + /* Write timer 2 */ + esb_unlock_registers(); + writel(val, ESB_TIMER2_REG); + + /* Reload */ + esb_unlock_registers(); + writew(ESB_WDT_RELOAD, ESB_RELOAD_REG); + + /* FIXME: Do we need to flush everything out? */ + + /* Done */ + heartbeat = time; + spin_unlock(&esb_lock); + return 0; +} + +/* + * /dev/watchdog handling + */ + +static int esb_open(struct inode *inode, struct file *file) +{ + /* /dev/watchdog can only be opened once */ + if (test_and_set_bit(0, &timer_alive)) + return -EBUSY; + + /* Reload and activate timer */ + esb_timer_start(); + + return nonseekable_open(inode, file); +} + +static int esb_release(struct inode *inode, struct file *file) +{ + /* Shut off the timer. */ + if (esb_expect_close == 42) + esb_timer_stop(); + else { + pr_crit("Unexpected close, not stopping watchdog!\n"); + esb_timer_keepalive(); + } + clear_bit(0, &timer_alive); + esb_expect_close = 0; + return 0; +} + +static ssize_t esb_write(struct file *file, const char __user *data, + size_t len, loff_t *ppos) +{ + /* See if we got the magic character 'V' and reload the timer */ + if (len) { + if (!nowayout) { + size_t i; + + /* note: just in case someone wrote the magic character + * five months ago... */ + esb_expect_close = 0; + + /* scan to see whether or not we got the + * magic character */ + for (i = 0; i != len; i++) { + char c; + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + esb_expect_close = 42; + } + } + + /* someone wrote to us, we should reload the timer */ + esb_timer_keepalive(); + } + return len; +} + +static long esb_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int new_options, retval = -EINVAL; + int new_heartbeat; + void __user *argp = (void __user *)arg; + int __user *p = argp; + static const struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .firmware_version = 0, + .identity = ESB_MODULE_NAME, + }; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(argp, &ident, + sizeof(ident)) ? -EFAULT : 0; + + case WDIOC_GETSTATUS: + return put_user(0, p); + + case WDIOC_GETBOOTSTATUS: + return put_user(triggered, p); + + case WDIOC_SETOPTIONS: + { + if (get_user(new_options, p)) + return -EFAULT; + + if (new_options & WDIOS_DISABLECARD) { + esb_timer_stop(); + retval = 0; + } + + if (new_options & WDIOS_ENABLECARD) { + esb_timer_start(); + retval = 0; + } + return retval; + } + case WDIOC_KEEPALIVE: + esb_timer_keepalive(); + return 0; + + case WDIOC_SETTIMEOUT: + { + if (get_user(new_heartbeat, p)) + return -EFAULT; + if (esb_timer_set_heartbeat(new_heartbeat)) + return -EINVAL; + esb_timer_keepalive(); + /* Fall */ + } + case WDIOC_GETTIMEOUT: + return put_user(heartbeat, p); + default: + return -ENOTTY; + } +} + +/* + * Kernel Interfaces + */ + +static const struct file_operations esb_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = esb_write, + .unlocked_ioctl = esb_ioctl, + .open = esb_open, + .release = esb_release, +}; + +static struct miscdevice esb_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &esb_fops, +}; + +/* + * Data for PCI driver interface + */ +static DEFINE_PCI_DEVICE_TABLE(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 __devinit esb_getdevice(struct pci_dev *pdev) +{ + if (pci_enable_device(pdev)) { + pr_err("failed to enable device\n"); + goto err_devput; + } + + if (pci_request_region(pdev, 0, ESB_MODULE_NAME)) { + pr_err("failed to request region\n"); + goto err_disable; + } + + BASEADDR = pci_ioremap_bar(pdev, 0); + if (BASEADDR == NULL) { + /* Something's wrong here, BASEADDR has to be set */ + pr_err("failed to get BASEADDR\n"); + goto err_release; + } + + /* Done */ + esb_pci = pdev; + return 1; + +err_release: + pci_release_region(pdev, 0); +err_disable: + pci_disable_device(pdev); +err_devput: + return 0; +} + +static void __devinit esb_initdevice(void) +{ + 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(esb_pci, ESB_CONFIG_REG, 0x0003); + + /* Check that the WDT isn't already locked */ + pci_read_config_byte(esb_pci, ESB_LOCK_REG, &val1); + if (val1 & ESB_WDT_LOCK) + pr_warn("nowayout already set\n"); + + /* Set the timer to watchdog mode and disable it for now */ + pci_write_config_byte(esb_pci, ESB_LOCK_REG, 0x00); + + /* Check if the watchdog was previously triggered */ + esb_unlock_registers(); + val2 = readw(ESB_RELOAD_REG); + if (val2 & ESB_WDT_TIMEOUT) + triggered = WDIOF_CARDRESET; + + /* Reset WDT_TIMEOUT flag and timers */ + esb_unlock_registers(); + writew((ESB_WDT_TIMEOUT | ESB_WDT_RELOAD), ESB_RELOAD_REG); + + /* And set the correct timeout value */ + esb_timer_set_heartbeat(heartbeat); +} + +static int __devinit esb_probe(struct pci_dev *pdev, + const struct pci_device_id *ent) +{ + int ret; + + cards_found++; + if (cards_found == 1) + pr_info("Intel 6300ESB WatchDog Timer Driver v%s\n", + ESB_VERSION); + + if (cards_found > 1) { + pr_err("This driver only supports 1 device\n"); + return -ENODEV; + } + + /* Check whether or not the hardware watchdog is there */ + if (!esb_getdevice(pdev) || esb_pci == NULL) + return -ENODEV; + + /* Check that the heartbeat value is within it's range; + if not reset to the default */ + if (heartbeat < 0x1 || heartbeat > 2 * 0x03ff) { + heartbeat = WATCHDOG_HEARTBEAT; + pr_info("heartbeat value must be 1<heartbeat<2046, using %d\n", + heartbeat); + } + + /* Initialize the watchdog and make sure it does not run */ + esb_initdevice(); + + /* Register the watchdog so that userspace has access to it */ + ret = misc_register(&esb_miscdev); + if (ret != 0) { + pr_err("cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + goto err_unmap; + } + pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n", + BASEADDR, heartbeat, nowayout); + return 0; + +err_unmap: + iounmap(BASEADDR); + pci_release_region(esb_pci, 0); + pci_disable_device(esb_pci); + esb_pci = NULL; + return ret; +} + +static void __devexit esb_remove(struct pci_dev *pdev) +{ + /* Stop the timer before we leave */ + if (!nowayout) + esb_timer_stop(); + + /* Deregister */ + misc_deregister(&esb_miscdev); + iounmap(BASEADDR); + pci_release_region(esb_pci, 0); + pci_disable_device(esb_pci); + esb_pci = NULL; +} + +static void esb_shutdown(struct pci_dev *pdev) +{ + esb_timer_stop(); +} + +static struct pci_driver esb_driver = { + .name = ESB_MODULE_NAME, + .id_table = esb_pci_tbl, + .probe = esb_probe, + .remove = __devexit_p(esb_remove), + .shutdown = esb_shutdown, +}; + +static int __init watchdog_init(void) +{ + return pci_register_driver(&esb_driver); +} + +static void __exit watchdog_cleanup(void) +{ + pci_unregister_driver(&esb_driver); + pr_info("Watchdog Module Unloaded\n"); +} + +module_init(watchdog_init); +module_exit(watchdog_cleanup); + +MODULE_AUTHOR("Ross Biro and David Härdeman"); +MODULE_DESCRIPTION("Watchdog driver for Intel 6300ESB chipsets"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |