Hi, Guenter Best Regards! Anson Huang > -----Original Message----- > From: Guenter Roeck [mailto:groeck7@xxxxxxxxx] On Behalf Of Guenter > Roeck > Sent: 2019年3月21日 8:32 > To: Anson Huang <anson.huang@xxxxxxx> > Cc: wim@xxxxxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; > shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; > festevam@xxxxxxxxx; catalin.marinas@xxxxxxx; will.deacon@xxxxxxx; > Aisheng Dong <aisheng.dong@xxxxxxx>; Daniel Baluta > <daniel.baluta@xxxxxxx>; heiko@xxxxxxxxx; horms+renesas@xxxxxxxxxxxx; > Andy Gross <andy.gross@xxxxxxxxxx>; maxime.ripard@xxxxxxxxxxx; > olof@xxxxxxxxx; bjorn.andersson@xxxxxxxxxx; jagan@xxxxxxxxxxxxxxxxxxxx; > enric.balletbo@xxxxxxxxxxxxx; ezequiel@xxxxxxxxxxxxx; > stefan.wahren@xxxxxxxx; marc.w.gonzalez@xxxxxxx; linux- > watchdog@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx > <linux-imx@xxxxxxx> > Subject: Re: [PATCH V8 2/4] watchdog: imx_sc: Add i.MX system controller > watchdog support > > On 3/20/19 5:22 PM, Anson Huang wrote: > > Hi, Guenter > > > > Best Regards! > > Anson Huang > > > >> -----Original Message----- > >> From: Guenter Roeck [mailto:groeck7@xxxxxxxxx] On Behalf Of Guenter > >> Roeck > >> Sent: 2019年3月20日 21:44 > >> To: Anson Huang <anson.huang@xxxxxxx> > >> Cc: wim@xxxxxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; > mark.rutland@xxxxxxx; > >> shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; > >> festevam@xxxxxxxxx; catalin.marinas@xxxxxxx; will.deacon@xxxxxxx; > >> Aisheng Dong <aisheng.dong@xxxxxxx>; Daniel Baluta > >> <daniel.baluta@xxxxxxx>; heiko@xxxxxxxxx; > horms+renesas@xxxxxxxxxxxx; > >> Andy Gross <andy.gross@xxxxxxxxxx>; maxime.ripard@xxxxxxxxxxx; > >> olof@xxxxxxxxx; bjorn.andersson@xxxxxxxxxx; > >> jagan@xxxxxxxxxxxxxxxxxxxx; enric.balletbo@xxxxxxxxxxxxx; > >> ezequiel@xxxxxxxxxxxxx; stefan.wahren@xxxxxxxx; > >> marc.w.gonzalez@xxxxxxx; linux- watchdog@xxxxxxxxxxxxxxx; > >> devicetree@xxxxxxxxxxxxxxx; linux-arm- kernel@xxxxxxxxxxxxxxxxxxx; > >> linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx> > >> 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 <Anson.Huang@xxxxxxx> > >> > >> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx> > >> > >> 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. > > Even when built as module, the driver will be loaded and instantiated when > its devicetree entry is parsed. That is what devicetree is about, after all. > There will be no insmod. OK, understand now, if there is new version needed, I will change it to be from device-tree, thanks. Anson. > > Guenter > > > 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 <yibin.gong@xxxxxxx>"); > >>> +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver"); > >>> +MODULE_LICENSE("GPL v2");
