diff options
Diffstat (limited to 'drivers/char/watchdog/mv64x60_wdt.c')
| -rw-r--r-- | drivers/char/watchdog/mv64x60_wdt.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/char/watchdog/mv64x60_wdt.c b/drivers/char/watchdog/mv64x60_wdt.c new file mode 100644 index 000000000000..1436aea3b28f --- /dev/null +++ b/drivers/char/watchdog/mv64x60_wdt.c @@ -0,0 +1,252 @@ +/* + * 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> This file is licensed under + * the terms of the GNU General Public License version 2. This program + * is licensed "as is" without any warranty of any kind, whether express + * or implied. + */ + +#include <linux/config.h> +#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 <asm/mv64x60.h> +#include <asm/uaccess.h> +#include <asm/io.h> + +/* MV64x60 WDC (config) register access definitions */ +#define MV64x60_WDC_CTL1_MASK (3 << 24) +#define MV64x60_WDC_CTL1(val) ((val & 3) << 24) +#define MV64x60_WDC_CTL2_MASK (3 << 26) +#define MV64x60_WDC_CTL2(val) ((val & 3) << 26) + +/* Flags bits */ +#define MV64x60_WDOG_FLAG_OPENED 0 +#define MV64x60_WDOG_FLAG_ENABLED 1 + +static unsigned long wdt_flags; +static int wdt_status; +static void __iomem *mv64x60_regs; +static int mv64x60_wdt_timeout; + +static void mv64x60_wdt_reg_write(u32 val) +{ + /* Allow write only to CTL1 / CTL2 fields, retaining values in + * other fields. + */ + u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC); + data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK); + data |= val; + writel(data, mv64x60_regs + MV64x60_WDT_WDC); +} + +static void mv64x60_wdt_service(void) +{ + /* Write 01 followed by 10 to CTL2 */ + mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01)); + mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02)); +} + +static void mv64x60_wdt_handler_disable(void) +{ + if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { + /* Write 01 followed by 10 to CTL1 */ + mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); + mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); + printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n"); + } +} + +static void mv64x60_wdt_handler_enable(void) +{ + if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) { + /* Write 01 followed by 10 to CTL1 */ + mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01)); + mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02)); + printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n"); + } +} + +static int mv64x60_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags)) + return -EBUSY; + + mv64x60_wdt_service(); + mv64x60_wdt_handler_enable(); + + return 0; +} + +static int mv64x60_wdt_release(struct inode *inode, struct file *file) +{ + mv64x60_wdt_service(); + +#if !defined(CONFIG_WATCHDOG_NOWAYOUT) + mv64x60_wdt_handler_disable(); +#endif + + clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags); + + return 0; +} + +static ssize_t mv64x60_wdt_write(struct file *file, const char *data, + size_t len, loff_t * ppos) +{ + if (*ppos != file->f_pos) + return -ESPIPE; + + if (len) + mv64x60_wdt_service(); + + return len; +} + +static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + int timeout; + static struct watchdog_info info = { + .options = WDIOF_KEEPALIVEPING, + .firmware_version = 0, + .identity = "MV64x60 watchdog", + }; + + switch (cmd) { + case WDIOC_GETSUPPORT: + if (copy_to_user((void *)arg, &info, sizeof(info))) + return -EFAULT; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + if (put_user(wdt_status, (int *)arg)) + return -EFAULT; + wdt_status &= ~WDIOF_KEEPALIVEPING; + break; + + case WDIOC_GETTEMP: + return -EOPNOTSUPP; + + case WDIOC_SETOPTIONS: + return -EOPNOTSUPP; + + case WDIOC_KEEPALIVE: + mv64x60_wdt_service(); + wdt_status |= WDIOF_KEEPALIVEPING; + break; + + case WDIOC_SETTIMEOUT: + return -EOPNOTSUPP; + + case WDIOC_GETTIMEOUT: + timeout = mv64x60_wdt_timeout * HZ; + if (put_user(timeout, (int *)arg)) + return -EFAULT; + break; + + default: + return -ENOIOCTLCMD; + } + + return 0; +} + +static struct file_operations mv64x60_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = mv64x60_wdt_write, + .ioctl = mv64x60_wdt_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 __devinit mv64x60_wdt_probe(struct device *dev) +{ + struct platform_device *pd = to_platform_device(dev); + struct mv64x60_wdt_pdata *pdata = pd->dev.platform_data; + int bus_clk = 133; + + mv64x60_wdt_timeout = 10; + if (pdata) { + mv64x60_wdt_timeout = pdata->timeout; + bus_clk = pdata->bus_clk; + } + + mv64x60_regs = mv64x60_get_bridge_vbase(); + + writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8, + mv64x60_regs + MV64x60_WDT_WDC); + + return misc_register(&mv64x60_wdt_miscdev); +} + +static int __devexit mv64x60_wdt_remove(struct device *dev) +{ + misc_deregister(&mv64x60_wdt_miscdev); + + mv64x60_wdt_service(); + mv64x60_wdt_handler_disable(); + + return 0; +} + +static struct device_driver mv64x60_wdt_driver = { + .name = MV64x60_WDT_NAME, + .bus = &platform_bus_type, + .probe = mv64x60_wdt_probe, + .remove = __devexit_p(mv64x60_wdt_remove), +}; + +static struct platform_device *mv64x60_wdt_dev; + +static int __init mv64x60_wdt_init(void) +{ + int ret; + + printk(KERN_INFO "MV64x60 watchdog driver\n"); + + mv64x60_wdt_dev = platform_device_register_simple(MV64x60_WDT_NAME, + -1, NULL, 0); + if (IS_ERR(mv64x60_wdt_dev)) { + ret = PTR_ERR(mv64x60_wdt_dev); + goto out; + } + + ret = driver_register(&mv64x60_wdt_driver); + out: + return ret; +} + +static void __exit mv64x60_wdt_exit(void) +{ + driver_unregister(&mv64x60_wdt_driver); + platform_device_unregister(mv64x60_wdt_dev); +} + +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_MISCDEV(WATCHDOG_MINOR); |