Messages in this thread | | | Subject | Re: [PATCH 2/4] watchdog: imx_sc: Add i.MX system controller watchdog support | From | Guenter Roeck <> | Date | Thu, 14 Feb 2019 06:50:33 -0800 |
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On 2/14/19 3:44 AM, Anson Huang wrote: > i.MX8QXP is an ARMv8 SoC which has a Cortex-M4 system controller > inside, the system controller is in charge of controlling power, > clock and watchdog etc.. > > This patch adds i.MX system controller watchdog driver support, > watchdog operation needs to be done in secure EL3 mode via > ARM-Trusted-Firmware, using SMC call, CPU will trap into > ARM-Trusted-Firmware and then it will request system controller > to do watchdog operation via IPC. > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com> > --- > drivers/watchdog/Kconfig | 13 +++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/imx_sc_wdt.c | 210 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 224 insertions(+) > create mode 100644 drivers/watchdog/imx_sc_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 65c3c42..5c5b8ba 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -625,6 +625,19 @@ config IMX2_WDT > To compile this driver as a module, choose M here: the > module will be called imx2_wdt. > > +config IMX_SC_WDT > + tristate "IMX SC Watchdog" > + depends on ARCH_MXC || COMPILE_TEST > + select WATCHDOG_CORE > + help > + This is the driver for the system controller watchdog > + on the NXP i.MX SoCs with system controller inside. > + If you have one of these processors and wish to have > + watchdog support enabled, say Y, otherwise say N. > + > + To compile this driver as a module, choose M here: the > + module will be called imx_sc_wdt. > + > config UX500_WATCHDOG > tristate "ST-Ericsson Ux500 watchdog" > depends on MFD_DB8500_PRCMU > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 4e78a8c..0c9da63 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -68,6 +68,7 @@ obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o > obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o > obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o > obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o > +obj-$(CONFIG_IMX_SC_WDT) += imx_sc_wdt.o > obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o > obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o > obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o > diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c > new file mode 100644 > index 0000000..ae52e34 > --- /dev/null > +++ b/drivers/watchdog/imx_sc_wdt.c > @@ -0,0 +1,210 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Copyright 2018-2019 NXP. > + */ > + > +#include <linux/arm-smccc.h> > +#include <linux/io.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/reboot.h> > +#include <linux/watchdog.h> > + > +#define DEFAULT_TIMEOUT 60 > +/* > + * Software timer tick implemented in scfw side, support 10ms to 0xffffffff ms > + * in theory, but for normal case, 1s~128s is enough, you can change this max > + * value in case it's not enough. > + */ > +#define MAX_TIMEOUT 128 > + > +#define IMX_SIP_TIMER 0xC2000002 > +#define IMX_SIP_TIMER_START_WDOG 0x01 > +#define IMX_SIP_TIMER_STOP_WDOG 0x02 > +#define IMX_SIP_TIMER_SET_WDOG_ACT 0x03 > +#define IMX_SIP_TIMER_PING_WDOG 0x04 > +#define IMX_SIP_TIMER_SET_TIMEOUT_WDOG 0x05 > +#define IMX_SIP_TIMER_GET_WDOG_STAT 0x06 > +#define IMX_SIP_TIMER_SET_PRETIME_WDOG 0x07 > + > +#define SC_TIMER_WDOG_ACTION_PARTITION 0 > + > +static bool nowayout = WATCHDOG_NOWAYOUT; > +module_param(nowayout, bool, 0000); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +static unsigned int timeout = DEFAULT_TIMEOUT; > +module_param(timeout, uint, 0000); > +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=" > + __MODULE_STRING(DEFAULT_TIMEOUT) ")"); > + > +static struct watchdog_device imx_sc_wdd; > + > +static int imx_sc_wdt_ping(struct watchdog_device *wdog) > +{ > + struct arm_smccc_res res; > + > + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_PING_WDOG, > + 0, 0, 0, 0, 0, 0, &res); > + > + return res.a0; > +} > + > +static int imx_sc_wdt_start(struct watchdog_device *wdog) > +{ > + struct arm_smccc_res res; > + > + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_START_WDOG, > + 0, 0, 0, 0, 0, 0, &res); > + if (res.a0) > + return res.a0; > + > + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_WDOG_ACT, > + SC_TIMER_WDOG_ACTION_PARTITION, > + 0, 0, 0, 0, 0, &res); > + > + return res.a0; > +} > + > +static int imx_sc_wdt_stop(struct watchdog_device *wdog) > +{ > + struct arm_smccc_res res; > + > + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_STOP_WDOG, > + 0, 0, 0, 0, 0, 0, &res); > + > + return res.a0; > +} > + > +static int imx_sc_wdt_set_timeout(struct watchdog_device *wdog, > + unsigned int timeout) > +{ > + struct arm_smccc_res res; > + > + wdog->timeout = timeout; > + arm_smccc_smc(IMX_SIP_TIMER, IMX_SIP_TIMER_SET_TIMEOUT_WDOG, > + timeout * 1000, 0, 0, 0, 0, 0, &res); > + > + return res.a0; > +} > + > +static const struct watchdog_ops imx_sc_wdt_ops = { > + .owner = THIS_MODULE, > + .start = imx_sc_wdt_start, > + .stop = imx_sc_wdt_stop, > + .ping = imx_sc_wdt_ping, > + .set_timeout = imx_sc_wdt_set_timeout, > +}; > + > +static const struct watchdog_info imx_sc_wdt_info = { > + .identity = "i.MX SC watchdog timer", > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | > + WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT, > +}; > + > +#ifdef CONFIG_PM_SLEEP > +static int imx_sc_wdt_suspend(struct device *dev) > +{ > + if (test_bit(WDOG_ACTIVE, &imx_sc_wdd.status)) > + imx_sc_wdt_stop(&imx_sc_wdd); > +
What is wrong with watchdog_active() ? It is used below ?
> + return 0; > +} > + > +static int imx_sc_wdt_resume(struct device *dev) > +{ > + if (test_bit(WDOG_ACTIVE, &imx_sc_wdd.status)) > + imx_sc_wdt_start(&imx_sc_wdd); > + > + return 0; > +} > + > +static const struct dev_pm_ops imx_sc_wdt_pm_ops = { > + .suspend = imx_sc_wdt_suspend, > + .resume = imx_sc_wdt_resume, > +}; > + > +#define IMX_SC_WDT_PM_OPS (&imx_sc_wdt_pm_ops) > + > +#else > + > +#define IMX_SC_WDT_PM_OPS NULL > + > +#endif > + > +static int imx_sc_wdt_probe(struct platform_device *pdev) > +{ > + struct watchdog_device *wdt = &imx_sc_wdd;
Please use devm_kzalloc() and drop the static variable. You can use dev_get_drvdata() to access it where needed.
> + int err; > + > + platform_set_drvdata(pdev, wdt); > + > + wdt->info = &imx_sc_wdt_info; > + wdt->ops = &imx_sc_wdt_ops; > + wdt->min_timeout = 1; > + wdt->max_timeout = MAX_TIMEOUT; > + wdt->parent = &pdev->dev; > + watchdog_set_drvdata(wdt, NULL); > + This is quite pointless.
> + err = watchdog_init_timeout(wdt, DEFAULT_TIMEOUT, &pdev->dev); > + if (err) { > + dev_err(&pdev->dev, "Failed to init the wdog timeout:%d\n", > + err); > + return err; > + } > + > + err = watchdog_register_device(wdt); > + if (err) { > + dev_err(&pdev->dev, "Failed to register watchdog device\n"); > + return err; > + } > + > + return 0; > +} > + > +static int imx_sc_wdt_remove(struct platform_device *pdev) > +{ > + struct watchdog_device *wdt = platform_get_drvdata(pdev); > + > + imx_sc_wdt_stop(wdt);
Any reason for not using watchdog_stop_on_unregister() ?
> + > + watchdog_unregister_device(wdt); > + > + return 0; > +} > + > +static void imx_sc_wdt_shutdown(struct platform_device *pdev) > +{ > + struct watchdog_device *wdt = platform_get_drvdata(pdev); > + > + if (watchdog_active(wdt)) > + imx_sc_wdt_stop(wdt); > +} > + Any reason for not using watchdog_stop_on_reboot() ?
> +static const struct of_device_id imx_sc_wdt_dt_ids[] = { > + { .compatible = "fsl,imx8qxp-sc-wdt", }, > + { /*sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, imx_sc_wdt_dt_ids); > + > +static struct platform_driver imx_sc_wdt_driver = { > + .probe = imx_sc_wdt_probe, > + .remove = imx_sc_wdt_remove, > + .shutdown = imx_sc_wdt_shutdown, > + .driver = { > + .name = "imx-sc-wdt", > + .of_match_table = imx_sc_wdt_dt_ids, > + .pm = IMX_SC_WDT_PM_OPS,
I prefer the use of SIMPLE_DEV_PM_OPS() together with __maybe_unused for the pm functions instead of #ifdef. This ensures that the unused code compiles even if PM_SLEEP is not enabled.
Thanks, Guenter
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