Messages in this thread | | | Date | Sat, 18 Apr 2015 08:52:58 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH V1 5/6] watchdog: da9062: DA9062 watchdog driver |
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On 04/17/2015 07:23 AM, S Twiss wrote: > From: S Twiss <stwiss.opensource@diasemi.com> > > Add watchdog driver support for DA9062 > > Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com> > Hi Steve,
Key question here is if the da9062 is really so much different to the da9062 that you can not use the same driver. I am especially concerned about the added da9062_reset_watchdog_timer(), given the delay it introduces.
Comments below.
Thanks, Guenter
> --- > > This patch applies against linux-next and v4.0 > > > > drivers/watchdog/Kconfig | 9 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/da9062_wdt.c | 249 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 259 insertions(+) > create mode 100644 drivers/watchdog/da9062_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 16f2023..62232d7 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -96,6 +96,15 @@ config DA9063_WATCHDOG > > This driver can be built as a module. The module name is da9063_wdt. > > +config DA9062_WATCHDOG > + tristate "Dialog DA9062 Watchdog" > + depends on MFD_DA9062 > + select WATCHDOG_CORE > + help > + Support for the watchdog in the DA9062 PMIC. > + > + This driver can be built as a module. The module name is da9062_wdt. > + > config GPIO_WATCHDOG > tristate "Watchdog device controlled through GPIO-line" > depends on OF_GPIO > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 5c19294..57ba815 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -179,6 +179,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o > # Architecture Independent > obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o > obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o > +obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o > obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o > obj-$(CONFIG_GPIO_WATCHDOG) += gpio_wdt.o > obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o > diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c > new file mode 100644 > index 0000000..ac4c255 > --- /dev/null > +++ b/drivers/watchdog/da9062_wdt.c > @@ -0,0 +1,249 @@ > +/* > + * da9062_wdt.c - WDT device driver for DA9062 > + * Copyright (C) 2015 Dialog Semiconductor Ltd. > + * > + * 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. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/watchdog.h> > +#include <linux/platform_device.h> > +#include <linux/uaccess.h> > +#include <linux/slab.h> > +#include <linux/delay.h> > +#include <linux/mfd/da9062/registers.h> > +#include <linux/mfd/da9062/core.h> > +#include <linux/regmap.h> > +#include <linux/of.h> > + > +static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; > +#define DA9062_TWDSCALE_DISABLE 0 > +#define DA9062_TWDSCALE_MIN 1 > +#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) > +#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN] > +#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX] > +#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1] > + > +struct da9062_watchdog { > + struct da9062 *hw; > + struct watchdog_device wdtdev; > +}; > + > +static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs) > +{ > + unsigned int i; > + > + for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) { > + if (wdt_timeout[i] >= secs) > + return i; > + } > + > + return DA9062_TWDSCALE_MAX; > +} > + > +static int da9062_reset_watchdog_timer(struct da9062 *hw) > +{ > + int ret; > + > + ret = regmap_update_bits(hw->regmap, > + DA9062AA_CONTROL_F, > + DA9062AA_WATCHDOG_MASK, > + DA9062AA_WATCHDOG_MASK); > + > + mdelay(300);
Really ? That seems to be excessive, especially given how often this function is called (for each ping!).
> + > + return ret; > +} > + > +static int da9062_wdt_update_timeout_register(struct da9062 *chip, > + unsigned int regval) > +{ > + int ret; > + > + ret = da9062_reset_watchdog_timer(chip); > + if (ret) > + dev_err(chip->dev, "Failed to ping the watchdog (err = %d)\n", > + ret); > + And no impact, so this doesn't really matter ?
> + return regmap_update_bits(chip->regmap, > + DA9062AA_CONTROL_D, > + DA9062AA_TWDSCALE_MASK, > + regval); > +} > + > +static int da9062_wdt_start(struct watchdog_device *wdd) > +{ > + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); > + unsigned int selector; > + int ret; > + > + selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout); > + ret = da9062_wdt_update_timeout_register(wdt->hw, selector); > + if (ret) > + dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n", > + ret); > + > + return ret; > +} > + > +static int da9062_wdt_stop(struct watchdog_device *wdd) > +{ > + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); > + int ret; > + > + ret = da9062_reset_watchdog_timer(wdt->hw); > + if (ret) > + dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n", > + ret); > + ping or reset ? And no impact, ie you just ignore the error ?
> + ret = regmap_update_bits(wdt->hw->regmap, > + DA9062AA_CONTROL_D, > + DA9062AA_TWDSCALE_MASK, > + DA9062_TWDSCALE_DISABLE); > + if (ret) > + dev_alert(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n", > + ret); > + > + return ret; > +} > + > +static int da9062_wdt_ping(struct watchdog_device *wdd) > +{ > + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); > + int ret; > + > + dev_dbg(wdt->hw->dev, "watchdog ping\n"); > + > + ret = da9062_reset_watchdog_timer(wdt->hw); > + if (ret) > + dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n", > + ret); > + > + return ret; > +} > + > +static int da9062_wdt_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) > +{ > + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); > + unsigned int selector; > + int ret; > + > + selector = da9062_wdt_timeout_to_sel(timeout); > + ret = da9062_wdt_update_timeout_register(wdt->hw, selector); > + if (ret) > + dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n", > + ret); > + else > + wdd->timeout = wdt_timeout[selector]; > + > + return ret; > +} > + > +/* E_WDG_WARN interrupt handler */ > +static irqreturn_t da9062_wdt_wdg_warn_irq_handler(int irq, void *data) > +{ > + struct da9062_watchdog *wdt = data; > + > + dev_notice(wdt->hw->dev, "Watchdog timeout warning trigger.\n"); > + return IRQ_HANDLED; > +} > + > +static const struct watchdog_info da9062_watchdog_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, > + .identity = "DA9062 WDT", > +}; > + > +static const struct watchdog_ops da9062_watchdog_ops = { > + .owner = THIS_MODULE, > + .start = da9062_wdt_start, > + .stop = da9062_wdt_stop, > + .ping = da9062_wdt_ping, > + .set_timeout = da9062_wdt_set_timeout, > +}; > + > +static int da9062_wdt_probe(struct platform_device *pdev) > +{ > + int ret; > + struct da9062 *chip; > + struct da9062_watchdog *wdt; > + int irq; > + > + chip = dev_get_drvdata(pdev->dev.parent); > + if (!chip) > + return -EINVAL; > + > + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); > + if (!wdt) > + return -ENOMEM; > + > + wdt->hw = chip; > + > + wdt->wdtdev.info = &da9062_watchdog_info; > + wdt->wdtdev.ops = &da9062_watchdog_ops; > + wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT; > + wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT; > + wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT; > + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; > + > + watchdog_set_drvdata(&wdt->wdtdev, wdt); > + dev_set_drvdata(&pdev->dev, wdt); > + > + irq = platform_get_irq_byname(pdev, "WDG_WARN"); > + if (irq < 0) > + dev_err(wdt->hw->dev, "Failed to get IRQ.\n");
But you still request the negative irq.
> + > + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, > + da9062_wdt_wdg_warn_irq_handler, > + IRQF_TRIGGER_LOW | IRQF_ONESHOT | IRQF_SHARED, > + "WDG_WARN", wdt); > + if (ret) { > + dev_err(wdt->hw->dev, > + "Failed to request watchdog device IRQ.\n");
Either this is an error, or it isn't. If it is, I would expect the driver to abort loading. If not, please don't use dev_err.
> + } > + > + ret = watchdog_register_device(&wdt->wdtdev); > + if (ret < 0) > + dev_err(wdt->hw->dev, > + "watchdog registration incomplete (%d)\n", ret);
incomplete ?
> + else > + dev_info(wdt->hw->dev, "installed DA9062 watchdog\n");
Please rop this message.
> + > + da9062_wdt_ping(&wdt->wdtdev); > + if (ret < 0) > + dev_err(wdt->hw->dev, > + "failed to ping the watchdog (%d)\n", ret); > + That ping is asking for an explanation. Does it imply that the watchdog is known to be running and can not be stopped ?
Also, the ping function already creates an error message. Please be less noisy with your messages.
> + return ret;
If the above ping fails, this will return an error without unregistering the watchdog device.
> +} > + > +static int da9062_wdt_remove(struct platform_device *pdev) > +{ > + struct da9062_watchdog *wdt = dev_get_drvdata(&pdev->dev); > + > + watchdog_unregister_device(&wdt->wdtdev); > + return 0; > +} > + > +static struct platform_driver da9062_wdt_driver = { > + .probe = da9062_wdt_probe, > + .remove = da9062_wdt_remove, > + .driver = { > + .name = "da9062-watchdog", > + }, > +}; > +module_platform_driver(da9062_wdt_driver); > + > +MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>"); > +MODULE_DESCRIPTION("WDT device driver for Dialog DA9062"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform: da9062-watchdog"); >
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