Hi, Guenter Best Regards! Anson Huang
> -----Original Message----- > From: Guenter Roeck [mailto:[email protected]] On Behalf Of Guenter > Roeck > Sent: 2019年3月20日 21:44 > To: Anson Huang <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > Aisheng Dong <[email protected]>; Daniel Baluta > <[email protected]>; [email protected]; [email protected]; > Andy Gross <[email protected]>; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; linux- > [email protected]; [email protected]; linux-arm- > [email protected]; [email protected]; dl-linux-imx > <[email protected]> > Subject: Re: [PATCH V8 2/4] watchdog: imx_sc: Add i.MX system controller > watchdog support > > On Fri, Mar 15, 2019 at 06:17:25AM +0000, 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 <[email protected]> > > Reviewed-by: Guenter Roeck <[email protected]> > > Waiting for bindings approval, though. Plus a minor comment below. > > Guenter > > > --- > > Changes since V7: > > - remove the dependence of IMX_SCU as it does NOT call SCU API > directly; > > - add more detail info into the help section of how this module works; > > - add back device id table since now we have watchdog node in DT. > > --- > > drivers/watchdog/Kconfig | 16 ++++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/imx_sc_wdt.c | 182 > > ++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 199 insertions(+) > > create mode 100644 drivers/watchdog/imx_sc_wdt.c > > > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index > > 242eea8..44a3158 100644 > > --- a/drivers/watchdog/Kconfig > > +++ b/drivers/watchdog/Kconfig > > @@ -641,6 +641,22 @@ 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 HAVE_ARM_SMCCC > > + select WATCHDOG_CORE > > + help > > + This is the driver for the system controller watchdog > > + on the NXP i.MX SoCs with system controller inside, the > > + watchdog driver will call ARM SMC API and trap into > > + ARM-Trusted-Firmware for operations, ARM-Trusted-Firmware > > + will request system controller to execute the operations. > > + 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 ba930e4..136d9f0 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..c8a087a > > --- /dev/null > > +++ b/drivers/watchdog/imx_sc_wdt.c > > @@ -0,0 +1,182 @@ > > +// 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; > > I still don't understand why you explicitly disable configuring the watchdog > timeout through devicetree (unless the user explicitly provides a timeout=0 > module parameter). Maybe add some comment if you send another version. I thought this watchdog will be built as module anyway, and user can pass the timeout parameter when insmod this module, so I just choose the way of getting it from module parameter. I will add a comment if there is another version needed. Thanks, Anson. > > > +module_param(timeout, uint, 0000); > > +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=" > > + __MODULE_STRING(DEFAULT_TIMEOUT) ")"); > > + > > +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 0; > > +} > > + > > +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 -EACCES; > > + > > + 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 ? -EACCES : 0; > > +} > > + > > +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 ? -EACCES : 0; > > +} > > + > > +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 ? -EACCES : 0; > > +} > > + > > +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, }; > > + > > +static int imx_sc_wdt_probe(struct platform_device *pdev) { > > + struct watchdog_device *imx_sc_wdd; > > + int ret; > > + > > + imx_sc_wdd = devm_kzalloc(&pdev->dev, sizeof(*imx_sc_wdd), > GFP_KERNEL); > > + if (!imx_sc_wdd) > > + return -ENOMEM; > > + > > + platform_set_drvdata(pdev, imx_sc_wdd); > > + > > + imx_sc_wdd->info = &imx_sc_wdt_info; > > + imx_sc_wdd->ops = &imx_sc_wdt_ops; > > + imx_sc_wdd->min_timeout = 1; > > + imx_sc_wdd->max_timeout = MAX_TIMEOUT; > > + imx_sc_wdd->parent = &pdev->dev; > > + imx_sc_wdd->timeout = DEFAULT_TIMEOUT; > > + > > + ret = watchdog_init_timeout(imx_sc_wdd, timeout, &pdev->dev); > > + if (ret) > > + dev_warn(&pdev->dev, "Failed to set timeout value, using > > +default\n"); > > + > > + watchdog_stop_on_reboot(imx_sc_wdd); > > + watchdog_stop_on_unregister(imx_sc_wdd); > > + > > + ret = devm_watchdog_register_device(&pdev->dev, imx_sc_wdd); > > + if (ret) { > > + dev_err(&pdev->dev, "Failed to register watchdog device\n"); > > + return ret; > > + } > > + > > + return 0; > > +} > > + > > +static int __maybe_unused imx_sc_wdt_suspend(struct device *dev) { > > + struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev); > > + > > + if (watchdog_active(imx_sc_wdd)) > > + imx_sc_wdt_stop(imx_sc_wdd); > > + > > + return 0; > > +} > > + > > +static int __maybe_unused imx_sc_wdt_resume(struct device *dev) { > > + struct watchdog_device *imx_sc_wdd = dev_get_drvdata(dev); > > + > > + if (watchdog_active(imx_sc_wdd)) > > + imx_sc_wdt_start(imx_sc_wdd); > > + > > + return 0; > > +} > > + > > +static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops, > > + imx_sc_wdt_suspend, imx_sc_wdt_resume); > > + > > +static const struct of_device_id imx_sc_wdt_dt_ids[] = { > > + { .compatible = "fsl,imx-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, > > + .driver = { > > + .name = "imx-sc-wdt", > > + .of_match_table = imx_sc_wdt_dt_ids, > > + .pm = &imx_sc_wdt_pm_ops, > > + }, > > +}; > > +module_platform_driver(imx_sc_wdt_driver); > > + > > +MODULE_AUTHOR("Robin Gong <[email protected]>"); > > +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver"); > > +MODULE_LICENSE("GPL v2");
