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    SubjectRe: [PATCH 05/07] Watchdog: DA9052/53 watchdog support v1
    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");
    >>>
    >>>
    >
    >
    > _______________________________________________
    > linaro-dev mailing list
    > linaro-dev@lists.linaro.org
    > http://lists.linaro.org/mailman/listinfo/linaro-dev



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