| Message ID | 1410984726-18944-3-git-send-email-carlo@caione.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 09/17/2014 01:12 PM, Carlo Caione wrote: > This patch adds the watchdog driver for the Amlogic Meson SoCs used also > to reboot the device. > > Signed-off-by: Carlo Caione <carlo@caione.org> > --- > drivers/watchdog/Kconfig | 10 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/meson_wdt.c | 237 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 248 insertions(+) > create mode 100644 drivers/watchdog/meson_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index f57312f..836cb00 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -443,6 +443,16 @@ config TEGRA_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called tegra_wdt. > > +config MESON_WATCHDOG > + tristate "Amlogic Meson SoCs watchdog support" > + depends on ARCH_MESON > + select WATCHDOG_CORE > + help > + Say Y here to include support for the watchdog timer > + in Amlogic Meson SoCs. > + To compile this driver as a module, choose M here: the > + module will be called meson_wdt. > + > # AVR32 Architecture > > config AT32AP700X_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 468c320..e7a9259 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -59,6 +59,7 @@ obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o > obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o > obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o > obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o > +obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/meson_wdt.c b/drivers/watchdog/meson_wdt.c > new file mode 100644 > index 0000000..3fbe147 > --- /dev/null > +++ b/drivers/watchdog/meson_wdt.c > @@ -0,0 +1,237 @@ > +/* > + * Meson Watchdog Driver > + * > + * Copyright (c) 2014 Carlo Caione > + * > + * 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/clk.h> > +#include <linux/delay.h> > +#include <linux/err.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/notifier.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/reboot.h> > +#include <linux/types.h> > +#include <linux/watchdog.h> > + > +#define DRV_NAME "meson_wdt" > + > +#define MESON_WDT_TC 0x00 > +#define MESON_WDT_TC_EN BIT(22) > +#define MESON_WDT_TC_TM_MASK 0x3fffff > +#define MESON_WDT_DC_RESET (3 << 24) > + > +#define MESON_WDT_RESET 0x04 > + Does this all use the same indentation ? Looks a bit odd. > +#define MESON_WDT_TIMEOUT 40 > +#define MESON_WDT_MIN_TIMEOUT 1 > +#define MESON_WDT_MAX_TIMEOUT 30 > + Default timeout is 40 seconds, maximum timeout is 30 seconds ? That doesn't really make much sense. What is the real maximum timeout ? If it is 0x3fffff / 100000, as the code suggests, you should set MAX_TIMEOUT to 41 or possibly (0x3fffff / 100000) so people understand what is going on. > +static bool nowayout = WATCHDOG_NOWAYOUT; > +static unsigned int timeout = MESON_WDT_TIMEOUT; > + > +struct meson_wdt_dev { > + struct watchdog_device wdt_dev; > + void __iomem *wdt_base; > + struct notifier_block restart_handler; > +}; > + > +static int meson_restart_handle(struct notifier_block *this, unsigned long mode, > + void *cmd) > +{ > + u32 tc_reboot = MESON_WDT_DC_RESET | MESON_WDT_TC_EN | 100; What does the magic 100 do ? > + struct meson_wdt_dev *meson_wdt = container_of(this, > + struct meson_wdt_dev, > + restart_handler); > + > + writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); > + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); > + Is this sequence necessary ? Just asking, looks a bit odd. > + while (1) { > + mdelay(5); > + writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); > + } > + > + return NOTIFY_DONE; > +} > + > +static int meson_wdt_ping(struct watchdog_device *wdt_dev) > +{ > + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); > + > + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); > + > + return 0; > +} > + > +static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev, > + unsigned int timeout) > +{ > + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); > + u32 reg; > + > + meson_wdt->wdt_dev.timeout = timeout; > + > + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); > + reg &= ~MESON_WDT_TC_TM_MASK; > + reg |= (timeout * 100 * 1000); A define for the clock rate might be helpful. > + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); > + > + meson_wdt_ping(wdt_dev); > + > + return 0; > +} > + > +static int meson_wdt_stop(struct watchdog_device *wdt_dev) > +{ > + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); > + u32 reg; > + > + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); Is this final ping really needed here ? > + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); > + reg &= ~MESON_WDT_TC_EN; > + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); > + > + return 0; > +} > + > +static int meson_wdt_start(struct watchdog_device *wdt_dev) > +{ > + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); > + u32 reg; > + int ret; > + > + ret = meson_wdt_set_timeout(&meson_wdt->wdt_dev, > + meson_wdt->wdt_dev.timeout); Not really sure if that is such a good idea here, as the set_timeout function does a bit more than just writing the timeout into the register. If you don't want to hard-code it here, I would suggest to write a little helper function which only writes it into the register (which would be called from both here and from meson_wdt_set_timeout). > + if (ret < 0) > + return ret; > + > + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); > + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); > + reg |= MESON_WDT_TC_EN; > + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); > + > + return 0; > +} > + > +static const struct watchdog_info meson_wdt_info = { > + .identity = DRV_NAME, > + .options = WDIOF_SETTIMEOUT | > + WDIOF_KEEPALIVEPING | > + WDIOF_MAGICCLOSE, > +}; > + > +static const struct watchdog_ops meson_wdt_ops = { > + .owner = THIS_MODULE, > + .start = meson_wdt_start, > + .stop = meson_wdt_stop, > + .ping = meson_wdt_ping, > + .set_timeout = meson_wdt_set_timeout, > +}; > + > +static int meson_wdt_probe(struct platform_device *pdev) > +{ > + struct resource *res; > + struct meson_wdt_dev *meson_wdt; > + int err; > + > + meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL); > + if (!meson_wdt) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + meson_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(meson_wdt->wdt_base)) > + return PTR_ERR(meson_wdt->wdt_base); > + > + meson_wdt->wdt_dev.parent = &pdev->dev; > + meson_wdt->wdt_dev.info = &meson_wdt_info; > + meson_wdt->wdt_dev.ops = &meson_wdt_ops; > + meson_wdt->wdt_dev.timeout = MESON_WDT_TIMEOUT; > + meson_wdt->wdt_dev.max_timeout = MESON_WDT_MAX_TIMEOUT; > + meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT; > + > + watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt); > + > + watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev); > + watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout); > + > + meson_wdt_stop(&meson_wdt->wdt_dev); > + > + err = watchdog_register_device(&meson_wdt->wdt_dev); > + if (unlikely(err)) > + return err; Please drop the unlikely. > + > + platform_set_drvdata(pdev, meson_wdt); > + > + meson_wdt->restart_handler.notifier_call = meson_restart_handle; > + meson_wdt->restart_handler.priority = 128; > + err = register_restart_handler(&meson_wdt->restart_handler); > + if (err) > + dev_err(&pdev->dev, > + "cannot register restart handler (err=%d)\n", err); > + > + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", > + meson_wdt->wdt_dev.timeout, nowayout); > + > + return 0; > +} > + > +static int meson_wdt_remove(struct platform_device *pdev) > +{ > + struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev); > + > + unregister_restart_handler(&meson_wdt->restart_handler); > + > + watchdog_unregister_device(&meson_wdt->wdt_dev); > + watchdog_set_drvdata(&meson_wdt->wdt_dev, NULL); Unnecessary. > + > + return 0; > +} > + > +static void meson_wdt_shutdown(struct platform_device *pdev) > +{ > + struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev); > + > + meson_wdt_stop(&meson_wdt->wdt_dev); > +} > + > +static const struct of_device_id meson_wdt_dt_ids[] = { > + { .compatible = "amlogic,meson-wdt" }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids); > + > +static struct platform_driver meson_wdt_driver = { > + .probe = meson_wdt_probe, > + .remove = meson_wdt_remove, > + .shutdown = meson_wdt_shutdown, > + .driver = { > + .owner = THIS_MODULE, > + .name = DRV_NAME, > + .of_match_table = meson_wdt_dt_ids, > + }, > +}; > + > +module_platform_driver(meson_wdt_driver); > + > +module_param(timeout, uint, 0); > +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); > + > +module_param(nowayout, bool, 0); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " > + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Carlo Caione <carlo@caione.org>"); > +MODULE_DESCRIPTION("Meson Watchdog Timer Driver"); >
On Fri, Sep 19, 2014 at 5:31 AM, Guenter Roeck <linux@roeck-us.net> wrote: > On 09/17/2014 01:12 PM, Carlo Caione wrote: >> >> This patch adds the watchdog driver for the Amlogic Meson SoCs used also >> to reboot the device. >> >> Signed-off-by: Carlo Caione <carlo@caione.org> >> --- >> drivers/watchdog/Kconfig | 10 ++ >> drivers/watchdog/Makefile | 1 + >> drivers/watchdog/meson_wdt.c | 237 >> +++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 248 insertions(+) >> create mode 100644 drivers/watchdog/meson_wdt.c >> >> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >> index f57312f..836cb00 100644 >> --- a/drivers/watchdog/Kconfig >> +++ b/drivers/watchdog/Kconfig >> @@ -443,6 +443,16 @@ config TEGRA_WATCHDOG >> To compile this driver as a module, choose M here: the >> module will be called tegra_wdt. >> >> +config MESON_WATCHDOG >> + tristate "Amlogic Meson SoCs watchdog support" >> + depends on ARCH_MESON >> + select WATCHDOG_CORE >> + help >> + Say Y here to include support for the watchdog timer >> + in Amlogic Meson SoCs. >> + To compile this driver as a module, choose M here: the >> + module will be called meson_wdt. >> + >> # AVR32 Architecture >> >> config AT32AP700X_WDT >> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile >> index 468c320..e7a9259 100644 >> --- a/drivers/watchdog/Makefile >> +++ b/drivers/watchdog/Makefile >> @@ -59,6 +59,7 @@ obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o >> obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o >> obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o >> obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o >> +obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o >> >> # AVR32 Architecture >> obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o >> diff --git a/drivers/watchdog/meson_wdt.c b/drivers/watchdog/meson_wdt.c >> new file mode 100644 >> index 0000000..3fbe147 >> --- /dev/null >> +++ b/drivers/watchdog/meson_wdt.c >> @@ -0,0 +1,237 @@ >> +/* >> + * Meson Watchdog Driver >> + * >> + * Copyright (c) 2014 Carlo Caione >> + * >> + * 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/clk.h> >> +#include <linux/delay.h> >> +#include <linux/err.h> >> +#include <linux/init.h> >> +#include <linux/io.h> >> +#include <linux/kernel.h> >> +#include <linux/module.h> >> +#include <linux/moduleparam.h> >> +#include <linux/notifier.h> >> +#include <linux/of.h> >> +#include <linux/platform_device.h> >> +#include <linux/reboot.h> >> +#include <linux/types.h> >> +#include <linux/watchdog.h> >> + >> +#define DRV_NAME "meson_wdt" >> + >> +#define MESON_WDT_TC 0x00 >> +#define MESON_WDT_TC_EN BIT(22) >> +#define MESON_WDT_TC_TM_MASK 0x3fffff >> +#define MESON_WDT_DC_RESET (3 << 24) >> + >> +#define MESON_WDT_RESET 0x04 >> + > > Does this all use the same indentation ? Looks a bit odd. It does actually. >> +#define MESON_WDT_TIMEOUT 40 >> +#define MESON_WDT_MIN_TIMEOUT 1 >> +#define MESON_WDT_MAX_TIMEOUT 30 >> + > > > Default timeout is 40 seconds, maximum timeout is 30 seconds ? > That doesn't really make much sense. What is the real maximum timeout ? > If it is 0x3fffff / 100000, as the code suggests, you should set > MAX_TIMEOUT to 41 or possibly (0x3fffff / 100000) so people understand > what is going on. I swapped the values, you are right. About the maximum values I wish I had proper documentation to answer your question. Anyway your guessing is probably right so I'll change it. >> +static bool nowayout = WATCHDOG_NOWAYOUT; >> +static unsigned int timeout = MESON_WDT_TIMEOUT; >> + >> +struct meson_wdt_dev { >> + struct watchdog_device wdt_dev; >> + void __iomem *wdt_base; >> + struct notifier_block restart_handler; >> +}; >> + >> +static int meson_restart_handle(struct notifier_block *this, unsigned >> long mode, >> + void *cmd) >> +{ >> + u32 tc_reboot = MESON_WDT_DC_RESET | MESON_WDT_TC_EN | 100; > > > What does the magic 100 do ? Just setting a really small timeout (I'm still not sure if 100 means actually 1ms timeout or just "the minimum timeout") >> + struct meson_wdt_dev *meson_wdt = container_of(this, >> + struct >> meson_wdt_dev, >> + restart_handler); >> + >> + writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); >> + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); >> + > > Is this sequence necessary ? Just asking, looks a bit odd. It was like that in the original code. I'll check if it is necessary. > >> + while (1) { >> + mdelay(5); >> + writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); >> + } >> + >> + return NOTIFY_DONE; >> +} >> + >> +static int meson_wdt_ping(struct watchdog_device *wdt_dev) >> +{ >> + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); >> + >> + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); >> + >> + return 0; >> +} >> + >> +static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev, >> + unsigned int timeout) >> +{ >> + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); >> + u32 reg; >> + >> + meson_wdt->wdt_dev.timeout = timeout; >> + >> + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); >> + reg &= ~MESON_WDT_TC_TM_MASK; >> + reg |= (timeout * 100 * 1000); > > > A define for the clock rate might be helpful. Agree >> + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); >> + >> + meson_wdt_ping(wdt_dev); >> + >> + return 0; >> +} >> + >> +static int meson_wdt_stop(struct watchdog_device *wdt_dev) >> +{ >> + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); >> + u32 reg; >> + >> + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); > > > Is this final ping really needed here ? I'll check it. >> + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); >> + reg &= ~MESON_WDT_TC_EN; >> + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); >> + >> + return 0; >> +} >> + >> +static int meson_wdt_start(struct watchdog_device *wdt_dev) >> +{ >> + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); >> + u32 reg; >> + int ret; >> + >> + ret = meson_wdt_set_timeout(&meson_wdt->wdt_dev, >> + meson_wdt->wdt_dev.timeout); > > > Not really sure if that is such a good idea here, as the set_timeout > function does a bit more than just writing the timeout into the register. > If you don't want to hard-code it here, I would suggest to write a > little helper function which only writes it into the register > (which would be called from both here and from meson_wdt_set_timeout). Ok. I'll fix it in v3. > >> + if (ret < 0) >> + return ret; >> + >> + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); >> + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); >> + reg |= MESON_WDT_TC_EN; >> + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); >> + >> + return 0; >> +} >> + >> +static const struct watchdog_info meson_wdt_info = { >> + .identity = DRV_NAME, >> + .options = WDIOF_SETTIMEOUT | >> + WDIOF_KEEPALIVEPING | >> + WDIOF_MAGICCLOSE, >> +}; >> + >> +static const struct watchdog_ops meson_wdt_ops = { >> + .owner = THIS_MODULE, >> + .start = meson_wdt_start, >> + .stop = meson_wdt_stop, >> + .ping = meson_wdt_ping, >> + .set_timeout = meson_wdt_set_timeout, >> +}; >> + >> +static int meson_wdt_probe(struct platform_device *pdev) >> +{ >> + struct resource *res; >> + struct meson_wdt_dev *meson_wdt; >> + int err; >> + >> + meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), >> GFP_KERNEL); >> + if (!meson_wdt) >> + return -ENOMEM; >> + >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + meson_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); >> + if (IS_ERR(meson_wdt->wdt_base)) >> + return PTR_ERR(meson_wdt->wdt_base); >> + >> + meson_wdt->wdt_dev.parent = &pdev->dev; >> + meson_wdt->wdt_dev.info = &meson_wdt_info; >> + meson_wdt->wdt_dev.ops = &meson_wdt_ops; >> + meson_wdt->wdt_dev.timeout = MESON_WDT_TIMEOUT; >> + meson_wdt->wdt_dev.max_timeout = MESON_WDT_MAX_TIMEOUT; >> + meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT; >> + >> + watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt); >> + >> + watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev); >> + watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout); >> + >> + meson_wdt_stop(&meson_wdt->wdt_dev); >> + >> + err = watchdog_register_device(&meson_wdt->wdt_dev); >> + if (unlikely(err)) >> + return err; > > > Please drop the unlikely. Ok >> + >> + platform_set_drvdata(pdev, meson_wdt); >> + >> + meson_wdt->restart_handler.notifier_call = meson_restart_handle; >> + meson_wdt->restart_handler.priority = 128; >> + err = register_restart_handler(&meson_wdt->restart_handler); >> + if (err) >> + dev_err(&pdev->dev, >> + "cannot register restart handler (err=%d)\n", >> err); >> + >> + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, >> nowayout=%d)", >> + meson_wdt->wdt_dev.timeout, nowayout); >> + >> + return 0; >> +} >> + >> +static int meson_wdt_remove(struct platform_device *pdev) >> +{ >> + struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev); >> + >> + unregister_restart_handler(&meson_wdt->restart_handler); >> + >> + watchdog_unregister_device(&meson_wdt->wdt_dev); >> + watchdog_set_drvdata(&meson_wdt->wdt_dev, NULL); > > > Unnecessary. Ok > >> + >> + return 0; >> +} >> + >> +static void meson_wdt_shutdown(struct platform_device *pdev) >> +{ >> + struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev); >> + >> + meson_wdt_stop(&meson_wdt->wdt_dev); >> +} >> + >> +static const struct of_device_id meson_wdt_dt_ids[] = { >> + { .compatible = "amlogic,meson-wdt" }, >> + { /* sentinel */ } >> +}; >> +MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids); >> + >> +static struct platform_driver meson_wdt_driver = { >> + .probe = meson_wdt_probe, >> + .remove = meson_wdt_remove, >> + .shutdown = meson_wdt_shutdown, >> + .driver = { >> + .owner = THIS_MODULE, >> + .name = DRV_NAME, >> + .of_match_table = meson_wdt_dt_ids, >> + }, >> +}; >> + >> +module_platform_driver(meson_wdt_driver); >> + >> +module_param(timeout, uint, 0); >> +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); >> + >> +module_param(nowayout, bool, 0); >> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " >> + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); >> + >> +MODULE_LICENSE("GPL"); >> +MODULE_AUTHOR("Carlo Caione <carlo@caione.org>"); >> +MODULE_DESCRIPTION("Meson Watchdog Timer Driver"); Thank you for the review.
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index f57312f..836cb00 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -443,6 +443,16 @@ config TEGRA_WATCHDOG To compile this driver as a module, choose M here: the module will be called tegra_wdt. +config MESON_WATCHDOG + tristate "Amlogic Meson SoCs watchdog support" + depends on ARCH_MESON + select WATCHDOG_CORE + help + Say Y here to include support for the watchdog timer + in Amlogic Meson SoCs. + To compile this driver as a module, choose M here: the + module will be called meson_wdt. + # AVR32 Architecture config AT32AP700X_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 468c320..e7a9259 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o +obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/meson_wdt.c b/drivers/watchdog/meson_wdt.c new file mode 100644 index 0000000..3fbe147 --- /dev/null +++ b/drivers/watchdog/meson_wdt.c @@ -0,0 +1,237 @@ +/* + * Meson Watchdog Driver + * + * Copyright (c) 2014 Carlo Caione + * + * 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/clk.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/notifier.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/types.h> +#include <linux/watchdog.h> + +#define DRV_NAME "meson_wdt" + +#define MESON_WDT_TC 0x00 +#define MESON_WDT_TC_EN BIT(22) +#define MESON_WDT_TC_TM_MASK 0x3fffff +#define MESON_WDT_DC_RESET (3 << 24) + +#define MESON_WDT_RESET 0x04 + +#define MESON_WDT_TIMEOUT 40 +#define MESON_WDT_MIN_TIMEOUT 1 +#define MESON_WDT_MAX_TIMEOUT 30 + +static bool nowayout = WATCHDOG_NOWAYOUT; +static unsigned int timeout = MESON_WDT_TIMEOUT; + +struct meson_wdt_dev { + struct watchdog_device wdt_dev; + void __iomem *wdt_base; + struct notifier_block restart_handler; +}; + +static int meson_restart_handle(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + u32 tc_reboot = MESON_WDT_DC_RESET | MESON_WDT_TC_EN | 100; + struct meson_wdt_dev *meson_wdt = container_of(this, + struct meson_wdt_dev, + restart_handler); + + writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); + + while (1) { + mdelay(5); + writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC); + } + + return NOTIFY_DONE; +} + +static int meson_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); + + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); + + return 0; +} + +static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int timeout) +{ + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); + u32 reg; + + meson_wdt->wdt_dev.timeout = timeout; + + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); + reg &= ~MESON_WDT_TC_TM_MASK; + reg |= (timeout * 100 * 1000); + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); + + meson_wdt_ping(wdt_dev); + + return 0; +} + +static int meson_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); + u32 reg; + + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); + reg &= ~MESON_WDT_TC_EN; + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); + + return 0; +} + +static int meson_wdt_start(struct watchdog_device *wdt_dev) +{ + struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev); + u32 reg; + int ret; + + ret = meson_wdt_set_timeout(&meson_wdt->wdt_dev, + meson_wdt->wdt_dev.timeout); + if (ret < 0) + return ret; + + writel(0, meson_wdt->wdt_base + MESON_WDT_RESET); + reg = readl(meson_wdt->wdt_base + MESON_WDT_TC); + reg |= MESON_WDT_TC_EN; + writel(reg, meson_wdt->wdt_base + MESON_WDT_TC); + + return 0; +} + +static const struct watchdog_info meson_wdt_info = { + .identity = DRV_NAME, + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops meson_wdt_ops = { + .owner = THIS_MODULE, + .start = meson_wdt_start, + .stop = meson_wdt_stop, + .ping = meson_wdt_ping, + .set_timeout = meson_wdt_set_timeout, +}; + +static int meson_wdt_probe(struct platform_device *pdev) +{ + struct resource *res; + struct meson_wdt_dev *meson_wdt; + int err; + + meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL); + if (!meson_wdt) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + meson_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(meson_wdt->wdt_base)) + return PTR_ERR(meson_wdt->wdt_base); + + meson_wdt->wdt_dev.parent = &pdev->dev; + meson_wdt->wdt_dev.info = &meson_wdt_info; + meson_wdt->wdt_dev.ops = &meson_wdt_ops; + meson_wdt->wdt_dev.timeout = MESON_WDT_TIMEOUT; + meson_wdt->wdt_dev.max_timeout = MESON_WDT_MAX_TIMEOUT; + meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT; + + watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt); + + watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev); + watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout); + + meson_wdt_stop(&meson_wdt->wdt_dev); + + err = watchdog_register_device(&meson_wdt->wdt_dev); + if (unlikely(err)) + return err; + + platform_set_drvdata(pdev, meson_wdt); + + meson_wdt->restart_handler.notifier_call = meson_restart_handle; + meson_wdt->restart_handler.priority = 128; + err = register_restart_handler(&meson_wdt->restart_handler); + if (err) + dev_err(&pdev->dev, + "cannot register restart handler (err=%d)\n", err); + + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", + meson_wdt->wdt_dev.timeout, nowayout); + + return 0; +} + +static int meson_wdt_remove(struct platform_device *pdev) +{ + struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev); + + unregister_restart_handler(&meson_wdt->restart_handler); + + watchdog_unregister_device(&meson_wdt->wdt_dev); + watchdog_set_drvdata(&meson_wdt->wdt_dev, NULL); + + return 0; +} + +static void meson_wdt_shutdown(struct platform_device *pdev) +{ + struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev); + + meson_wdt_stop(&meson_wdt->wdt_dev); +} + +static const struct of_device_id meson_wdt_dt_ids[] = { + { .compatible = "amlogic,meson-wdt" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids); + +static struct platform_driver meson_wdt_driver = { + .probe = meson_wdt_probe, + .remove = meson_wdt_remove, + .shutdown = meson_wdt_shutdown, + .driver = { + .owner = THIS_MODULE, + .name = DRV_NAME, + .of_match_table = meson_wdt_dt_ids, + }, +}; + +module_platform_driver(meson_wdt_driver); + +module_param(timeout, uint, 0); +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Carlo Caione <carlo@caione.org>"); +MODULE_DESCRIPTION("Meson Watchdog Timer Driver");
This patch adds the watchdog driver for the Amlogic Meson SoCs used also to reboot the device. Signed-off-by: Carlo Caione <carlo@caione.org> --- drivers/watchdog/Kconfig | 10 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/meson_wdt.c | 237 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 248 insertions(+) create mode 100644 drivers/watchdog/meson_wdt.c