| Message ID | 148dd2d6912211bc468c30acf85a463192576039.1427356791.git.baruch@tkos.co.il (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/26/2015 12:59 AM, Baruch Siach wrote: > This commit add a driver for the watchdog functionality of the Conexant CX92755 > SoC, from the Digicolor series of SoCs. Of 8 system timers provided by the > CX92755, the first one, timer A, can reset the chip when its counter reaches > zero. This driver uses this capability to provide userspace with a standard > watchdog, using the watchdog timer driver core framework. This driver also > implements a reboot handler for the reboot(2) system call. > > The watchdog driver shares the timer registers with the CX92755 timer driver > (drivers/clocksource/timer-digicolor.c). The timer driver, however, uses only > timers other than A, so both drivers should coexist. > > Signed-off-by: Baruch Siach <baruch@tkos.co.il> Almost there. Couple of nitpicks below. Thanks, Guenter > --- > v2: > Address the comments of Guenter Roeck: > > * Set default timeout to max_timeout > * Move watchdog timer set code to a helper routine to avoid code duplication > * Update watchdog timer on .set_timeout callback > * Fix iomap leak on error path > * Change restart registration error message to a warning > * Use devm_clk_get() to acquire the clock > --- > drivers/watchdog/Kconfig | 10 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/digicolor_wdt.c | 206 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 217 insertions(+) > create mode 100644 drivers/watchdog/digicolor_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 16f202350997..7d73d6c78cf6 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -515,6 +515,16 @@ config MEDIATEK_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called mtk_wdt. > > +config DIGICOLOR_WATCHDOG > + tristate "Conexant Digicolor SoCs watchdog support" > + depends on ARCH_DIGICOLOR > + select WATCHDOG_CORE > + help > + Say Y here to include support for the watchdog timer > + in Conexant Digicolor SoCs. > + To compile this driver as a module, choose M here: the > + module will be called digicolor_wdt. > + > # AVR32 Architecture > > config AT32AP700X_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 5c19294d1c30..0721f10e8d13 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -64,6 +64,7 @@ obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o > obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o > obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o > obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o > +obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/digicolor_wdt.c b/drivers/watchdog/digicolor_wdt.c > new file mode 100644 > index 000000000000..99981c54c1b9 > --- /dev/null > +++ b/drivers/watchdog/digicolor_wdt.c > @@ -0,0 +1,206 @@ > +/* > + * Watchdog driver for Conexant Digicolor > + * > + * Copyright (C) 2015 Paradox Innovation 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. > + */ > + > +#include <linux/types.h> > +#include <linux/module.h> > +#include <linux/io.h> > +#include <linux/delay.h> > +#include <linux/clk.h> > +#include <linux/watchdog.h> > +#include <linux/reboot.h> > +#include <linux/platform_device.h> > +#include <linux/of_address.h> > + > +#define TIMER_A_CONTROL 0 > +#define TIMER_A_COUNT 4 > + > +#define TIMER_A_ENABLE_COUNT BIT(0) > +#define TIMER_A_ENABLE_WATCHDOG BIT(1) > + > +struct dc_wdt { > + void __iomem *base; > + struct clk *clk; > + struct notifier_block restart_handler; > + spinlock_t lock; > +}; > + > +static unsigned timeout; > +module_param(timeout, uint, 0); > +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); > + > +static void dc_wdt_set(struct dc_wdt *wdt, u32 ticks) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&wdt->lock, flags); > + > + writel_relaxed(0, wdt->base + TIMER_A_CONTROL); > + writel_relaxed(ticks, wdt->base + TIMER_A_COUNT); > + writel_relaxed(TIMER_A_ENABLE_COUNT | TIMER_A_ENABLE_WATCHDOG, > + wdt->base + TIMER_A_CONTROL); > + > + spin_unlock_irqrestore(&wdt->lock, flags); > +} > + > +static int dc_restart_handler(struct notifier_block *this, unsigned long mode, > + void *cmd) > +{ > + struct dc_wdt *wdt = container_of(this, struct dc_wdt, restart_handler); > + > + dc_wdt_set(wdt, 1); > + /* wait for reset to assert... */ > + mdelay(500); > + > + return NOTIFY_DONE; > +} > + > +static int dc_wdt_start(struct watchdog_device *wdog) > +{ > + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); > + > + dc_wdt_set(wdt, wdog->timeout * clk_get_rate(wdt->clk)); > + > + return 0; > +} > + > +static int dc_wdt_stop(struct watchdog_device *wdog) > +{ > + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); > + > + writel_relaxed(0, wdt->base + TIMER_A_CONTROL); > + > + return 0; > +} > + > +static int dc_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t) > +{ > + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); > + > + dc_wdt_set(wdt, t * clk_get_rate(wdt->clk)); > + wdog->timeout = t; > + > + return 0; > +} > + > +static unsigned int dc_wdt_get_timeleft(struct watchdog_device *wdog) > +{ > + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); > + uint32_t count = readl_relaxed(wdt->base + TIMER_A_COUNT); > + > + return (count / clk_get_rate(wdt->clk)); Unnecessary ( ). > +} > + > +static struct watchdog_ops dc_wdt_ops = { > + .owner = THIS_MODULE, > + .start = dc_wdt_start, > + .stop = dc_wdt_stop, > + .set_timeout = dc_wdt_set_timeout, > + .get_timeleft = dc_wdt_get_timeleft, > +}; > + > +static struct watchdog_info dc_wdt_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE > + | WDIOF_KEEPALIVEPING, > + .identity = "Conexant Digicolor Watchdog", > +}; > + > +static struct watchdog_device dc_wdt_wdd = { > + .info = &dc_wdt_info, > + .ops = &dc_wdt_ops, > + .min_timeout = 1, > +}; > + > +static int dc_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->of_node; > + struct dc_wdt *wdt; > + int ret; > + > + wdt = devm_kzalloc(dev, sizeof(struct dc_wdt), GFP_KERNEL); > + if (!wdt) > + return -ENOMEM; > + platform_set_drvdata(pdev, wdt); > + > + wdt->base = of_iomap(np, 0); > + if (!wdt->base) { > + dev_err(dev, "Failed to remap watchdog regs"); > + return -ENODEV; > + } > + > + wdt->clk = devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(wdt->clk)) { > + ret = PTR_ERR(wdt->clk); > + goto err_clk; > + } > + dc_wdt_wdd.max_timeout = U32_MAX / clk_get_rate(wdt->clk); > + dc_wdt_wdd.timeout = dc_wdt_wdd.max_timeout; > + > + spin_lock_init(&wdt->lock); > + > + watchdog_set_drvdata(&dc_wdt_wdd, wdt); > + watchdog_init_timeout(&dc_wdt_wdd, timeout, dev); > + ret = watchdog_register_device(&dc_wdt_wdd); > + if (ret) { > + dev_err(dev, "Failed to register watchdog device"); > + goto err_wdt; > + } > + > + wdt->restart_handler.notifier_call = dc_restart_handler; > + wdt->restart_handler.priority = 128; > + ret = register_restart_handler(&wdt->restart_handler); > + if (ret) > + dev_warn(&pdev->dev, "cannot register restart handler\n"); > + > + return 0; > + > +err_wdt: > +err_clk: Please use only one label. > + iounmap(wdt->base); > + return ret; > +} > + > +static int dc_wdt_remove(struct platform_device *pdev) > +{ > + struct dc_wdt *wdt = platform_get_drvdata(pdev); > + > + unregister_restart_handler(&wdt->restart_handler); > + watchdog_unregister_device(&dc_wdt_wdd); > + iounmap(wdt->base); > + > + return 0; > +} > + > +static void dc_wdt_shutdown(struct platform_device *pdev) > +{ > + dc_wdt_stop(&dc_wdt_wdd); > +} > + > +static const struct of_device_id dc_wdt_of_match[] = { > + { .compatible = "cnxt,cx92755-wdt", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, dc_wdt_of_match); > + > +static struct platform_driver dc_wdt_driver = { > + .probe = dc_wdt_probe, > + .remove = dc_wdt_remove, > + .shutdown = dc_wdt_shutdown, > + .driver = { > + .name = "digicolor-wdt", > + .of_match_table = dc_wdt_of_match, > + }, > +}; > +module_platform_driver(dc_wdt_driver); > + > +MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); > +MODULE_DESCRIPTION("Driver for Conexant Digicolor watchdog timer"); > +MODULE_LICENSE("GPL"); >
On 03/26/2015 10:40 PM, Shubhrajyoti Datta wrote: > > + > +static int dc_restart_handler(struct notifier_block *this, unsigned long mode, > + void *cmd) > +{ > + struct dc_wdt *wdt = container_of(this, struct dc_wdt, restart_handler); > + > + dc_wdt_set(wdt, 1); > + /* wait for reset to assert... */ > + mdelay(500); > > > How is the 500 calculated ? > Also is it possible to sleep here? > sleep: No. It would also be pretty pointless, since this is after all the very last step of rebooting the system. Guenter
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 16f202350997..7d73d6c78cf6 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -515,6 +515,16 @@ config MEDIATEK_WATCHDOG To compile this driver as a module, choose M here: the module will be called mtk_wdt. +config DIGICOLOR_WATCHDOG + tristate "Conexant Digicolor SoCs watchdog support" + depends on ARCH_DIGICOLOR + select WATCHDOG_CORE + help + Say Y here to include support for the watchdog timer + in Conexant Digicolor SoCs. + To compile this driver as a module, choose M here: the + module will be called digicolor_wdt. + # AVR32 Architecture config AT32AP700X_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 5c19294d1c30..0721f10e8d13 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o +obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/digicolor_wdt.c b/drivers/watchdog/digicolor_wdt.c new file mode 100644 index 000000000000..99981c54c1b9 --- /dev/null +++ b/drivers/watchdog/digicolor_wdt.c @@ -0,0 +1,206 @@ +/* + * Watchdog driver for Conexant Digicolor + * + * Copyright (C) 2015 Paradox Innovation 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. + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/watchdog.h> +#include <linux/reboot.h> +#include <linux/platform_device.h> +#include <linux/of_address.h> + +#define TIMER_A_CONTROL 0 +#define TIMER_A_COUNT 4 + +#define TIMER_A_ENABLE_COUNT BIT(0) +#define TIMER_A_ENABLE_WATCHDOG BIT(1) + +struct dc_wdt { + void __iomem *base; + struct clk *clk; + struct notifier_block restart_handler; + spinlock_t lock; +}; + +static unsigned timeout; +module_param(timeout, uint, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); + +static void dc_wdt_set(struct dc_wdt *wdt, u32 ticks) +{ + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + + writel_relaxed(0, wdt->base + TIMER_A_CONTROL); + writel_relaxed(ticks, wdt->base + TIMER_A_COUNT); + writel_relaxed(TIMER_A_ENABLE_COUNT | TIMER_A_ENABLE_WATCHDOG, + wdt->base + TIMER_A_CONTROL); + + spin_unlock_irqrestore(&wdt->lock, flags); +} + +static int dc_restart_handler(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + struct dc_wdt *wdt = container_of(this, struct dc_wdt, restart_handler); + + dc_wdt_set(wdt, 1); + /* wait for reset to assert... */ + mdelay(500); + + return NOTIFY_DONE; +} + +static int dc_wdt_start(struct watchdog_device *wdog) +{ + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); + + dc_wdt_set(wdt, wdog->timeout * clk_get_rate(wdt->clk)); + + return 0; +} + +static int dc_wdt_stop(struct watchdog_device *wdog) +{ + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); + + writel_relaxed(0, wdt->base + TIMER_A_CONTROL); + + return 0; +} + +static int dc_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t) +{ + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); + + dc_wdt_set(wdt, t * clk_get_rate(wdt->clk)); + wdog->timeout = t; + + return 0; +} + +static unsigned int dc_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct dc_wdt *wdt = watchdog_get_drvdata(wdog); + uint32_t count = readl_relaxed(wdt->base + TIMER_A_COUNT); + + return (count / clk_get_rate(wdt->clk)); +} + +static struct watchdog_ops dc_wdt_ops = { + .owner = THIS_MODULE, + .start = dc_wdt_start, + .stop = dc_wdt_stop, + .set_timeout = dc_wdt_set_timeout, + .get_timeleft = dc_wdt_get_timeleft, +}; + +static struct watchdog_info dc_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE + | WDIOF_KEEPALIVEPING, + .identity = "Conexant Digicolor Watchdog", +}; + +static struct watchdog_device dc_wdt_wdd = { + .info = &dc_wdt_info, + .ops = &dc_wdt_ops, + .min_timeout = 1, +}; + +static int dc_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct dc_wdt *wdt; + int ret; + + wdt = devm_kzalloc(dev, sizeof(struct dc_wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + platform_set_drvdata(pdev, wdt); + + wdt->base = of_iomap(np, 0); + if (!wdt->base) { + dev_err(dev, "Failed to remap watchdog regs"); + return -ENODEV; + } + + wdt->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(wdt->clk)) { + ret = PTR_ERR(wdt->clk); + goto err_clk; + } + dc_wdt_wdd.max_timeout = U32_MAX / clk_get_rate(wdt->clk); + dc_wdt_wdd.timeout = dc_wdt_wdd.max_timeout; + + spin_lock_init(&wdt->lock); + + watchdog_set_drvdata(&dc_wdt_wdd, wdt); + watchdog_init_timeout(&dc_wdt_wdd, timeout, dev); + ret = watchdog_register_device(&dc_wdt_wdd); + if (ret) { + dev_err(dev, "Failed to register watchdog device"); + goto err_wdt; + } + + wdt->restart_handler.notifier_call = dc_restart_handler; + wdt->restart_handler.priority = 128; + ret = register_restart_handler(&wdt->restart_handler); + if (ret) + dev_warn(&pdev->dev, "cannot register restart handler\n"); + + return 0; + +err_wdt: +err_clk: + iounmap(wdt->base); + return ret; +} + +static int dc_wdt_remove(struct platform_device *pdev) +{ + struct dc_wdt *wdt = platform_get_drvdata(pdev); + + unregister_restart_handler(&wdt->restart_handler); + watchdog_unregister_device(&dc_wdt_wdd); + iounmap(wdt->base); + + return 0; +} + +static void dc_wdt_shutdown(struct platform_device *pdev) +{ + dc_wdt_stop(&dc_wdt_wdd); +} + +static const struct of_device_id dc_wdt_of_match[] = { + { .compatible = "cnxt,cx92755-wdt", }, + {}, +}; +MODULE_DEVICE_TABLE(of, dc_wdt_of_match); + +static struct platform_driver dc_wdt_driver = { + .probe = dc_wdt_probe, + .remove = dc_wdt_remove, + .shutdown = dc_wdt_shutdown, + .driver = { + .name = "digicolor-wdt", + .of_match_table = dc_wdt_of_match, + }, +}; +module_platform_driver(dc_wdt_driver); + +MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); +MODULE_DESCRIPTION("Driver for Conexant Digicolor watchdog timer"); +MODULE_LICENSE("GPL");
This commit add a driver for the watchdog functionality of the Conexant CX92755 SoC, from the Digicolor series of SoCs. Of 8 system timers provided by the CX92755, the first one, timer A, can reset the chip when its counter reaches zero. This driver uses this capability to provide userspace with a standard watchdog, using the watchdog timer driver core framework. This driver also implements a reboot handler for the reboot(2) system call. The watchdog driver shares the timer registers with the CX92755 timer driver (drivers/clocksource/timer-digicolor.c). The timer driver, however, uses only timers other than A, so both drivers should coexist. Signed-off-by: Baruch Siach <baruch@tkos.co.il> --- v2: Address the comments of Guenter Roeck: * Set default timeout to max_timeout * Move watchdog timer set code to a helper routine to avoid code duplication * Update watchdog timer on .set_timeout callback * Fix iomap leak on error path * Change restart registration error message to a warning * Use devm_clk_get() to acquire the clock --- drivers/watchdog/Kconfig | 10 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/digicolor_wdt.c | 206 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 217 insertions(+) create mode 100644 drivers/watchdog/digicolor_wdt.c