Re: [PATCH 05/07] Watchdog: DA9052/53 watchdog support v1

[Shubhrajyoti <shubhrajyoti@ti.com>]

Hi Ashish,
Some comments / suggestions .

On Friday 30 March 2012 03:02 PM, Ashish Jangam wrote:
> Any update on this patch?
> On Tue, 2012-03-13 at 17:57 +0530, Ashish Jangam wrote:
>> Any update on below patch?
>> On Mon, 2012-02-06 at 18:18 +0530, Ashish Jangam wrote:
>>> 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.
May be you can consider some documentation on module compilation.
>>> +
>>>  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;
So it is initialised regardless of any compile time options?
>>> +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;
Is this needed ?
>>> +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);
Could you explain the delay?
>>> +
>>> +		/* 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);
Did not understand this?
>>> +		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);
Could we move to watchdog registration instead of the misc one ?
>>> +
>>> +	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");
>>>
>>>
>
>
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