diff options
Diffstat (limited to 'drivers/watchdog/mv64x60_wdt.c')
| -rw-r--r-- | drivers/watchdog/mv64x60_wdt.c | 324 |
1 files changed, 0 insertions, 324 deletions
diff --git a/drivers/watchdog/mv64x60_wdt.c b/drivers/watchdog/mv64x60_wdt.c deleted file mode 100644 index 894aa63488d3..000000000000 --- a/drivers/watchdog/mv64x60_wdt.c +++ /dev/null @@ -1,324 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface - * - * Author: James Chapman <jchapman@katalix.com> - * - * Platform-specific setup code should configure the dog to generate - * interrupt or reset as required. This code only enables/disables - * and services the watchdog. - * - * Derived from mpc8xx_wdt.c, with the following copyright. - * - * 2002 (c) Florian Schirmer <jolt@tuxbox.org> - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <linux/fs.h> -#include <linux/init.h> -#include <linux/kernel.h> -#include <linux/miscdevice.h> -#include <linux/module.h> -#include <linux/watchdog.h> -#include <linux/platform_device.h> -#include <linux/mv643xx.h> -#include <linux/uaccess.h> -#include <linux/io.h> - -#define MV64x60_WDT_WDC_OFFSET 0 - -/* - * The watchdog configuration register contains a pair of 2-bit fields, - * 1. a reload field, bits 27-26, which triggers a reload of - * the countdown register, and - * 2. an enable field, bits 25-24, which toggles between - * enabling and disabling the watchdog timer. - * Bit 31 is a read-only field which indicates whether the - * watchdog timer is currently enabled. - * - * The low 24 bits contain the timer reload value. - */ -#define MV64x60_WDC_ENABLE_SHIFT 24 -#define MV64x60_WDC_SERVICE_SHIFT 26 -#define MV64x60_WDC_ENABLED_SHIFT 31 - -#define MV64x60_WDC_ENABLED_TRUE 1 -#define MV64x60_WDC_ENABLED_FALSE 0 - -/* Flags bits */ -#define MV64x60_WDOG_FLAG_OPENED 0 - -static unsigned long wdt_flags; -static int wdt_status; -static void __iomem *mv64x60_wdt_regs; -static int mv64x60_wdt_timeout; -static int mv64x60_wdt_count; -static unsigned int bus_clk; -static char expect_close; -static DEFINE_SPINLOCK(mv64x60_wdt_spinlock); - -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 int mv64x60_wdt_toggle_wdc(int enabled_predicate, int field_shift) -{ - u32 data; - u32 enabled; - int ret = 0; - - spin_lock(&mv64x60_wdt_spinlock); - data = readl(mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET); - enabled = (data >> MV64x60_WDC_ENABLED_SHIFT) & 1; - - /* only toggle the requested field if enabled state matches predicate */ - if ((enabled ^ enabled_predicate) == 0) { - /* We write a 1, then a 2 -- to the appropriate field */ - data = (1 << field_shift) | mv64x60_wdt_count; - writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET); - - data = (2 << field_shift) | mv64x60_wdt_count; - writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET); - ret = 1; - } - spin_unlock(&mv64x60_wdt_spinlock); - - return ret; -} - -static void mv64x60_wdt_service(void) -{ - mv64x60_wdt_toggle_wdc(MV64x60_WDC_ENABLED_TRUE, - MV64x60_WDC_SERVICE_SHIFT); -} - -static void mv64x60_wdt_handler_enable(void) -{ - if (mv64x60_wdt_toggle_wdc(MV64x60_WDC_ENABLED_FALSE, - MV64x60_WDC_ENABLE_SHIFT)) { - mv64x60_wdt_service(); - pr_notice("watchdog activated\n"); - } -} - -static void mv64x60_wdt_handler_disable(void) -{ - if (mv64x60_wdt_toggle_wdc(MV64x60_WDC_ENABLED_TRUE, - MV64x60_WDC_ENABLE_SHIFT)) - pr_notice("watchdog deactivated\n"); -} - -static void mv64x60_wdt_set_timeout(unsigned int timeout) -{ - /* maximum bus cycle count is 0xFFFFFFFF */ - if (timeout > 0xFFFFFFFF / bus_clk) - timeout = 0xFFFFFFFF / bus_clk; - - mv64x60_wdt_count = timeout * bus_clk >> 8; - mv64x60_wdt_timeout = timeout; -} - -static int mv64x60_wdt_open(struct inode *inode, struct file *file) -{ - if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags)) - return -EBUSY; - - if (nowayout) - __module_get(THIS_MODULE); - - mv64x60_wdt_handler_enable(); - - return stream_open(inode, file); -} - -static int mv64x60_wdt_release(struct inode *inode, struct file *file) -{ - if (expect_close == 42) - mv64x60_wdt_handler_disable(); - else { - pr_crit("unexpected close, not stopping timer!\n"); - mv64x60_wdt_service(); - } - expect_close = 0; - - clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags); - - return 0; -} - -static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data, - size_t len, loff_t *ppos) -{ - if (len) { - if (!nowayout) { - size_t i; - - expect_close = 0; - - for (i = 0; i != len; i++) { - char c; - if (get_user(c, data + i)) - return -EFAULT; - if (c == 'V') - expect_close = 42; - } - } - mv64x60_wdt_service(); - } - - return len; -} - -static long mv64x60_wdt_ioctl(struct file *file, - unsigned int cmd, unsigned long arg) -{ - int timeout; - int options; - void __user *argp = (void __user *)arg; - static const struct watchdog_info info = { - .options = WDIOF_SETTIMEOUT | - WDIOF_MAGICCLOSE | - WDIOF_KEEPALIVEPING, - .firmware_version = 0, - .identity = "MV64x60 watchdog", - }; - - switch (cmd) { - case WDIOC_GETSUPPORT: - if (copy_to_user(argp, &info, sizeof(info))) - return -EFAULT; - break; - - case WDIOC_GETSTATUS: - case WDIOC_GETBOOTSTATUS: - if (put_user(wdt_status, (int __user *)argp)) - return -EFAULT; - wdt_status &= ~WDIOF_KEEPALIVEPING; - break; - - case WDIOC_GETTEMP: - return -EOPNOTSUPP; - - case WDIOC_SETOPTIONS: - if (get_user(options, (int __user *)argp)) - return -EFAULT; - - if (options & WDIOS_DISABLECARD) - mv64x60_wdt_handler_disable(); - - if (options & WDIOS_ENABLECARD) - mv64x60_wdt_handler_enable(); - break; - - case WDIOC_KEEPALIVE: - mv64x60_wdt_service(); - wdt_status |= WDIOF_KEEPALIVEPING; - break; - - case WDIOC_SETTIMEOUT: - if (get_user(timeout, (int __user *)argp)) - return -EFAULT; - mv64x60_wdt_set_timeout(timeout); - fallthrough; - - case WDIOC_GETTIMEOUT: - if (put_user(mv64x60_wdt_timeout, (int __user *)argp)) - return -EFAULT; - break; - - default: - return -ENOTTY; - } - - return 0; -} - -static const struct file_operations mv64x60_wdt_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .write = mv64x60_wdt_write, - .unlocked_ioctl = mv64x60_wdt_ioctl, - .compat_ioctl = compat_ptr_ioctl, - .open = mv64x60_wdt_open, - .release = mv64x60_wdt_release, -}; - -static struct miscdevice mv64x60_wdt_miscdev = { - .minor = WATCHDOG_MINOR, - .name = "watchdog", - .fops = &mv64x60_wdt_fops, -}; - -static int mv64x60_wdt_probe(struct platform_device *dev) -{ - struct mv64x60_wdt_pdata *pdata = dev_get_platdata(&dev->dev); - struct resource *r; - int timeout = 10; - - bus_clk = 133; /* in MHz */ - if (pdata) { - timeout = pdata->timeout; - bus_clk = pdata->bus_clk; - } - - /* Since bus_clk is truncated MHz, actual frequency could be - * up to 1MHz higher. Round up, since it's better to time out - * too late than too soon. - */ - bus_clk++; - bus_clk *= 1000000; /* convert to Hz */ - - r = platform_get_resource(dev, IORESOURCE_MEM, 0); - if (!r) - return -ENODEV; - - mv64x60_wdt_regs = devm_ioremap(&dev->dev, r->start, resource_size(r)); - if (mv64x60_wdt_regs == NULL) - return -ENOMEM; - - mv64x60_wdt_set_timeout(timeout); - - mv64x60_wdt_handler_disable(); /* in case timer was already running */ - - return misc_register(&mv64x60_wdt_miscdev); -} - -static int mv64x60_wdt_remove(struct platform_device *dev) -{ - misc_deregister(&mv64x60_wdt_miscdev); - - mv64x60_wdt_handler_disable(); - - return 0; -} - -static struct platform_driver mv64x60_wdt_driver = { - .probe = mv64x60_wdt_probe, - .remove = mv64x60_wdt_remove, - .driver = { - .name = MV64x60_WDT_NAME, - }, -}; - -static int __init mv64x60_wdt_init(void) -{ - pr_info("MV64x60 watchdog driver\n"); - - return platform_driver_register(&mv64x60_wdt_driver); -} - -static void __exit mv64x60_wdt_exit(void) -{ - platform_driver_unregister(&mv64x60_wdt_driver); -} - -module_init(mv64x60_wdt_init); -module_exit(mv64x60_wdt_exit); - -MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); -MODULE_DESCRIPTION("MV64x60 watchdog driver"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:" MV64x60_WDT_NAME); |