This driver adds support for the watchdog functionality provided by the Dialog Semiconductor DA9052/53 PMIC chip.
This patch is functionally tested on Samsung SMDKV6410.
Signed-off-by: David Dajun Chen dchen@diasemi.com Signed-off-by: Ashish Jangam ashish.jangam@kpitcummins.com --- Documentation/watchdog/watchdog-parameters.txt | 5 + drivers/watchdog/Kconfig | 6 + drivers/watchdog/Makefile | 1 + drivers/watchdog/da9052_wdt.c | 333 ++++++++++++++++++++++++ 4 files changed, 345 insertions(+), 0 deletions(-) create mode 100644 drivers/watchdog/da9052_wdt.c diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt index 17ddd82..04fddba 100644 --- a/Documentation/watchdog/watchdog-parameters.txt +++ b/Documentation/watchdog/watchdog-parameters.txt @@ -78,6 +78,11 @@ wd0_timeout: Default watchdog0 timeout in 1/10secs wd1_timeout: Default watchdog1 timeout in 1/10secs wd2_timeout: Default watchdog2 timeout in 1/10secs ------------------------------------------------- +da9052wdt: +timeout: Watchdog timeout in seconds. 2<= timeout <=131, default=2.048s +nowayout: Watchdog cannot be stopped once started + (default=kernel config parameter) +------------------------------------------------- davinci_wdt: heartbeat: Watchdog heartbeat period in seconds from 1 to 600, default 60 ------------------------------------------------- diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 877b107..3fb9633 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -63,6 +63,12 @@ config SOFT_WATCHDOG To compile this driver as a module, choose M here: the module will be called softdog.
+config DA9052_WATCHDOG + tristate "Dialog DA9052/DA9053 Watchdog" + depends on PMIC_DA9052 + help + Support for the watchdog in the DA9052-BC and DA9053-AA/Bx PMICs. + config WM831X_WATCHDOG tristate "WM831x watchdog" depends on MFD_WM831X diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index e8f479a..0ecbe5a 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -166,4 +166,5 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o +obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o diff --git a/drivers/watchdog/da9052_wdt.c b/drivers/watchdog/da9052_wdt.c new file mode 100644 index 0000000..b08091e --- /dev/null +++ b/drivers/watchdog/da9052_wdt.c @@ -0,0 +1,333 @@ +/* + * System monitoring driver for DA9052 PMICs. + * + * Copyright(c) 2012 Dialog Semiconductor Ltd. + * + * Author: Dajun Chen dchen@diasemi.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. + * + */ + +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/uaccess.h> +#include <linux/platform_device.h> +#include <linux/time.h> +#include <linux/watchdog.h> +#include <linux/types.h> +#include <linux/kernel.h> + +#include <linux/mfd/da9052/reg.h> +#include <linux/mfd/da9052/da9052.h> + +static int nowayout = WATCHDOG_NOWAYOUT; +static int wdt_state = WDIOS_DISABLECARD; +static struct miscdevice da9052_wdt_miscdev; +static unsigned long da9052_wdt_users; +static int da9052_wdt_expect_close; +struct da9052 *da9052; +static DEFINE_MUTEX(wdt_mutex); + +static struct { + u8 reg_val; + int time; /* Seconds */ +} da9052_wdt_maps[] = { + { 1, 2 }, + { 2, 4 }, + { 3, 8 }, + { 4, 16 }, + { 5, 32 }, + { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ + { 6, 65 }, + { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ + { 7, 131 }, +}; + +static int da9052_wdt_set_timeout(struct da9052 *da9052, unsigned char timeout) +{ + int ret; + + /* Disable the Watchdog timer for 150us before changing the + * time out value + */ + ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, + DA9052_CONTROLD_TWDSCALE, 0); + if (ret < 0) { + dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n", + ret); + return ret; + } + + mutex_lock(&wdt_mutex); + wdt_state = (timeout == 0) ? WDIOS_DISABLECARD : WDIOS_ENABLECARD; + mutex_unlock(&wdt_mutex); + + if (timeout) { + udelay(150); + + /* Set the desired timeout */ + ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, + DA9052_CONTROLD_TWDSCALE, timeout); + if (ret < 0) { + dev_err(da9052->dev, + "Failed to update timescale bit, %d\n", ret); + return ret; + } + } + + return 0; +} + +static int da9052_wdt_start(struct da9052 *da9052) +{ + int ret = 0; + + + if (wdt_state == WDIOS_DISABLECARD) { + /* Default 2.048s */ + ret = da9052_wdt_set_timeout(da9052, 1); + if (ret <= 0) + goto err; + + mutex_lock(&wdt_mutex); + wdt_state = WDIOS_ENABLECARD; + mutex_unlock(&wdt_mutex); + } + +err: + return ret; +} + +static int da9052_wdt_stop(struct da9052 *da9052) +{ + int ret = 0; + + mutex_lock(&wdt_mutex); + + if (wdt_state == WDIOS_ENABLECARD) { + ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, + DA9052_CONTROLD_TWDSCALE, 0); + if (ret < 0) { + dev_err(da9052->dev, + "Failed to disable watchdog bit strobe bit, %d\n", + ret); + goto err; + } + + wdt_state = WDIOS_DISABLECARD; + } + +err: + mutex_unlock(&wdt_mutex); + return ret; +} + +static void da9052_wdt_strobe(struct da9052 *da9052) +{ + int ret; + + if (wdt_state == WDIOS_ENABLECARD) { + ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, + DA9052_CONTROLD_WATCHDOG, 1 << 7); + if (ret < 0) { + dev_err(da9052->dev, + "Failed to update watchdog strobe bit, %d\n", + ret); + return; + } + } +} + +static int da9052_wdt_open(struct inode *inode, struct file *file) +{ + int ret; + + if (test_and_set_bit(0, &da9052_wdt_users)) + return -EBUSY; + + ret = da9052_wdt_start(da9052); + if (ret < 0) + return ret; + + return nonseekable_open(inode, file); +} + +static int da9052_wdt_release(struct inode *inode, struct file *file) +{ + int ret = 0; + + if (da9052_wdt_expect_close == 42) + ret = da9052_wdt_stop(da9052); + else + da9052_wdt_strobe(da9052); + + da9052_wdt_expect_close = 0; + clear_bit(0, &da9052_wdt_users); + + return ret; +} + +static struct watchdog_info da9052_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "DA9052 Watchdog", +}; + +static long da9052_wdt_ioctl(struct file *file, uint cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int ret = 0, timeout, i, __user *p = argp; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user(argp, &da9052_wdt_info, + sizeof(da9052_wdt_info)) ? -EFAULT : 0; + break; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, p); + break; + case WDIOC_SETOPTIONS: + { + int options; + ret = get_user(options, p); + if (ret) + break; + + if (options == WDIOS_ENABLECARD) + ret = da9052_wdt_start(da9052); + + if (options == WDIOS_DISABLECARD) + ret = da9052_wdt_stop(da9052); + + break; + } + case WDIOC_KEEPALIVE: + da9052_wdt_strobe(da9052); + break; + case WDIOC_SETTIMEOUT: + ret = get_user(timeout, p); + if (ret) + break; + + for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) + if (da9052_wdt_maps[i].time == timeout) + break; + if (i == ARRAY_SIZE(da9052_wdt_maps)) + ret = -EINVAL; + else + ret = da9052_wdt_set_timeout(da9052, + da9052_wdt_maps[i].reg_val); + + break; + case WDIOC_GETTIMEOUT: + ret = da9052_reg_read(da9052, DA9052_CONTROL_D_REG); + if (ret < 0) + break; + + ret &= DA9052_CONTROLD_TWDSCALE; + for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) + if (da9052_wdt_maps[i].reg_val == ret) + break; + if (i == ARRAY_SIZE(da9052_wdt_maps)) + ret = -EINVAL; + else + ret = put_user(da9052_wdt_maps[i].time, p); + + break; + default: + return -ENOTTY; + } + + return ret; +} + +static ssize_t da9052_wdt_write(struct file *file, + const char __user *data, size_t count, + loff_t *ppos) +{ + size_t i; + + /* Check the magic character 'V' and reload the timer */ + if (count) { + if (!nowayout) { + da9052_wdt_expect_close = 0; + + /* scan for magic character */ + for (i = 0; i != count; i++) { + char c; + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + da9052_wdt_expect_close = 42; + } + /* someone wrote to us, we should reload the timer */ + da9052_wdt_strobe(da9052); + } + } + return count; +} + +static const struct file_operations da9052_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .unlocked_ioctl = da9052_wdt_ioctl, + .write = da9052_wdt_write, + .open = da9052_wdt_open, + .release = da9052_wdt_release, +}; + +static struct miscdevice da9052_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "da9052-wdt", + .fops = &da9052_wdt_fops, +}; + +static int __devinit da9052_wdt_probe(struct platform_device *pdev) +{ + int ret; + + da9052 = dev_get_drvdata(pdev->dev.parent); + + ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, + DA9052_CONTROLD_TWDSCALE, 0); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n", + ret); + return ret; + } + + da9052_wdt_miscdev.parent = &pdev->dev; + + ret = misc_register(&da9052_wdt_miscdev); + + return ret; +} + +static int __devexit da9052_wdt_remove(struct platform_device *dev) +{ + misc_deregister(&da9052_wdt_miscdev); + + return 0; +} + +static struct platform_driver da9052_wdt_driver = { + .probe = da9052_wdt_probe, + .remove = __devexit_p(da9052_wdt_remove), + .driver = { + .name = "da9052-watchdog", + .owner = THIS_MODULE, + }, +}; + +module_platform_driver(da9052_wdt_driver); + +MODULE_AUTHOR("David Dajun Chen dchen@diasemi.com"); +MODULE_DESCRIPTION("DA9052 SM Device Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:da9052-wdt");