diff options
author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2011-03-25 16:41:20 +0100 |
---|---|---|
committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2011-03-25 16:41:20 +0100 |
commit | 7bf7e370d5919112c223a269462cd0b546903829 (patch) | |
tree | 03ccc715239df14ae168277dbccc9d9cf4d8a2c8 /drivers/watchdog/jz4740_wdt.c | |
parent | mtd: mtdswap: fix compilation warning (diff) | |
parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vir... (diff) | |
download | linux-7bf7e370d5919112c223a269462cd0b546903829.tar.xz linux-7bf7e370d5919112c223a269462cd0b546903829.zip |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus-1
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits)
[media] rc: update for bitop name changes
fs: simplify iget & friends
fs: pull inode->i_lock up out of writeback_single_inode
fs: rename inode_lock to inode_hash_lock
fs: move i_wb_list out from under inode_lock
fs: move i_sb_list out from under inode_lock
fs: remove inode_lock from iput_final and prune_icache
fs: Lock the inode LRU list separately
fs: factor inode disposal
fs: protect inode->i_state with inode->i_lock
lib, arch: add filter argument to show_mem and fix private implementations
SLUB: Write to per cpu data when allocating it
slub: Fix debugobjects with lockless fastpath
autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
autofs4 - remove autofs4_lock
autofs4 - fix d_manage() return on rcu-walk
autofs4 - fix autofs4_expire_indirect() traversal
autofs4 - fix dentry leak in autofs4_expire_direct()
autofs4 - reinstate last used update on access
vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
...
NOTE!
This merge commit was created to fix compilation error. The block
tree was merged upstream and removed the 'elv_queue_empty()'
function which the new 'mtdswap' driver is using. So a simple
merge of the mtd tree with upstream does not compile. And the
mtd tree has already be published, so re-basing it is not an option.
To fix this unfortunate situation, I had to merge upstream into the
mtd-2.6.git tree without committing, put the fixup patch on top of
this, and then commit this. The result is that we do not have commits
which do not compile.
In other words, this merge commit "merges" 3 things: the MTD tree, the
upstream tree, and the fixup patch.
Diffstat (limited to 'drivers/watchdog/jz4740_wdt.c')
-rw-r--r-- | drivers/watchdog/jz4740_wdt.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/watchdog/jz4740_wdt.c b/drivers/watchdog/jz4740_wdt.c new file mode 100644 index 000000000000..684ba01fb540 --- /dev/null +++ b/drivers/watchdog/jz4740_wdt.c @@ -0,0 +1,322 @@ +/* + * Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net> + * JZ4740 Watchdog driver + * + * 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. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/init.h> +#include <linux/bitops.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <linux/device.h> +#include <linux/clk.h> +#include <linux/slab.h> + +#include <asm/mach-jz4740/timer.h> + +#define JZ_REG_WDT_TIMER_DATA 0x0 +#define JZ_REG_WDT_COUNTER_ENABLE 0x4 +#define JZ_REG_WDT_TIMER_COUNTER 0x8 +#define JZ_REG_WDT_TIMER_CONTROL 0xC + +#define JZ_WDT_CLOCK_PCLK 0x1 +#define JZ_WDT_CLOCK_RTC 0x2 +#define JZ_WDT_CLOCK_EXT 0x4 + +#define WDT_IN_USE 0 +#define WDT_OK_TO_CLOSE 1 + +#define JZ_WDT_CLOCK_DIV_SHIFT 3 + +#define JZ_WDT_CLOCK_DIV_1 (0 << JZ_WDT_CLOCK_DIV_SHIFT) +#define JZ_WDT_CLOCK_DIV_4 (1 << JZ_WDT_CLOCK_DIV_SHIFT) +#define JZ_WDT_CLOCK_DIV_16 (2 << JZ_WDT_CLOCK_DIV_SHIFT) +#define JZ_WDT_CLOCK_DIV_64 (3 << JZ_WDT_CLOCK_DIV_SHIFT) +#define JZ_WDT_CLOCK_DIV_256 (4 << JZ_WDT_CLOCK_DIV_SHIFT) +#define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT) + +#define DEFAULT_HEARTBEAT 5 +#define MAX_HEARTBEAT 2048 + +static struct { + void __iomem *base; + struct resource *mem; + struct clk *rtc_clk; + unsigned long status; +} jz4740_wdt; + +static int heartbeat = DEFAULT_HEARTBEAT; + + +static void jz4740_wdt_service(void) +{ + writew(0x0, jz4740_wdt.base + JZ_REG_WDT_TIMER_COUNTER); +} + +static void jz4740_wdt_set_heartbeat(int new_heartbeat) +{ + unsigned int rtc_clk_rate; + unsigned int timeout_value; + unsigned short clock_div = JZ_WDT_CLOCK_DIV_1; + + heartbeat = new_heartbeat; + + rtc_clk_rate = clk_get_rate(jz4740_wdt.rtc_clk); + + timeout_value = rtc_clk_rate * heartbeat; + while (timeout_value > 0xffff) { + if (clock_div == JZ_WDT_CLOCK_DIV_1024) { + /* Requested timeout too high; + * use highest possible value. */ + timeout_value = 0xffff; + break; + } + timeout_value >>= 2; + clock_div += (1 << JZ_WDT_CLOCK_DIV_SHIFT); + } + + writeb(0x0, jz4740_wdt.base + JZ_REG_WDT_COUNTER_ENABLE); + writew(clock_div, jz4740_wdt.base + JZ_REG_WDT_TIMER_CONTROL); + + writew((u16)timeout_value, jz4740_wdt.base + JZ_REG_WDT_TIMER_DATA); + writew(0x0, jz4740_wdt.base + JZ_REG_WDT_TIMER_COUNTER); + writew(clock_div | JZ_WDT_CLOCK_RTC, + jz4740_wdt.base + JZ_REG_WDT_TIMER_CONTROL); + + writeb(0x1, jz4740_wdt.base + JZ_REG_WDT_COUNTER_ENABLE); +} + +static void jz4740_wdt_enable(void) +{ + jz4740_timer_enable_watchdog(); + jz4740_wdt_set_heartbeat(heartbeat); +} + +static void jz4740_wdt_disable(void) +{ + jz4740_timer_disable_watchdog(); + writeb(0x0, jz4740_wdt.base + JZ_REG_WDT_COUNTER_ENABLE); +} + +static int jz4740_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(WDT_IN_USE, &jz4740_wdt.status)) + return -EBUSY; + + jz4740_wdt_enable(); + + return nonseekable_open(inode, file); +} + +static ssize_t jz4740_wdt_write(struct file *file, const char *data, + size_t len, loff_t *ppos) +{ + if (len) { + size_t i; + + clear_bit(WDT_OK_TO_CLOSE, &jz4740_wdt.status); + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, data + i)) + return -EFAULT; + + if (c == 'V') + set_bit(WDT_OK_TO_CLOSE, &jz4740_wdt.status); + } + jz4740_wdt_service(); + } + + return len; +} + +static const struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING, + .identity = "jz4740 Watchdog", +}; + +static long jz4740_wdt_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + int ret = -ENOTTY; + int heartbeat_seconds; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user((struct watchdog_info *)arg, &ident, + sizeof(ident)) ? -EFAULT : 0; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, (int *)arg); + break; + + case WDIOC_KEEPALIVE: + jz4740_wdt_service(); + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(heartbeat_seconds, (int __user *)arg)) + return -EFAULT; + + jz4740_wdt_set_heartbeat(heartbeat_seconds); + return 0; + + case WDIOC_GETTIMEOUT: + return put_user(heartbeat, (int *)arg); + + default: + break; + } + + return ret; +} + +static int jz4740_wdt_release(struct inode *inode, struct file *file) +{ + jz4740_wdt_service(); + + if (test_and_clear_bit(WDT_OK_TO_CLOSE, &jz4740_wdt.status)) + jz4740_wdt_disable(); + + clear_bit(WDT_IN_USE, &jz4740_wdt.status); + return 0; +} + +static const struct file_operations jz4740_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = jz4740_wdt_write, + .unlocked_ioctl = jz4740_wdt_ioctl, + .open = jz4740_wdt_open, + .release = jz4740_wdt_release, +}; + +static struct miscdevice jz4740_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &jz4740_wdt_fops, +}; + +static int __devinit jz4740_wdt_probe(struct platform_device *pdev) +{ + int ret = 0, size; + struct resource *res; + struct device *dev = &pdev->dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (res == NULL) { + dev_err(dev, "failed to get memory region resource\n"); + return -ENXIO; + } + + size = resource_size(res); + jz4740_wdt.mem = request_mem_region(res->start, size, pdev->name); + if (jz4740_wdt.mem == NULL) { + dev_err(dev, "failed to get memory region\n"); + return -EBUSY; + } + + jz4740_wdt.base = ioremap_nocache(res->start, size); + if (jz4740_wdt.base == NULL) { + dev_err(dev, "failed to map memory region\n"); + ret = -EBUSY; + goto err_release_region; + } + + jz4740_wdt.rtc_clk = clk_get(NULL, "rtc"); + if (IS_ERR(jz4740_wdt.rtc_clk)) { + dev_err(dev, "cannot find RTC clock\n"); + ret = PTR_ERR(jz4740_wdt.rtc_clk); + goto err_iounmap; + } + + ret = misc_register(&jz4740_wdt_miscdev); + if (ret < 0) { + dev_err(dev, "cannot register misc device\n"); + goto err_disable_clk; + } + + return 0; + +err_disable_clk: + clk_put(jz4740_wdt.rtc_clk); +err_iounmap: + iounmap(jz4740_wdt.base); +err_release_region: + release_mem_region(jz4740_wdt.mem->start, + resource_size(jz4740_wdt.mem)); + return ret; +} + + +static int __devexit jz4740_wdt_remove(struct platform_device *pdev) +{ + jz4740_wdt_disable(); + misc_deregister(&jz4740_wdt_miscdev); + clk_put(jz4740_wdt.rtc_clk); + + iounmap(jz4740_wdt.base); + jz4740_wdt.base = NULL; + + release_mem_region(jz4740_wdt.mem->start, + resource_size(jz4740_wdt.mem)); + jz4740_wdt.mem = NULL; + + return 0; +} + + +static struct platform_driver jz4740_wdt_driver = { + .probe = jz4740_wdt_probe, + .remove = __devexit_p(jz4740_wdt_remove), + .driver = { + .name = "jz4740-wdt", + .owner = THIS_MODULE, + }, +}; + + +static int __init jz4740_wdt_init(void) +{ + return platform_driver_register(&jz4740_wdt_driver); +} +module_init(jz4740_wdt_init); + +static void __exit jz4740_wdt_exit(void) +{ + platform_driver_unregister(&jz4740_wdt_driver); +} +module_exit(jz4740_wdt_exit); + +MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>"); +MODULE_DESCRIPTION("jz4740 Watchdog Driver"); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, + "Watchdog heartbeat period in seconds from 1 to " + __MODULE_STRING(MAX_HEARTBEAT) ", default " + __MODULE_STRING(DEFAULT_HEARTBEAT)); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS("platform:jz4740-wdt"); |