Messages in this thread | | | Subject | Re: [PATCH V3 2/4] watchdog: imx_sc: Add i.MX system controller watchdog support | From | Guenter Roeck <> | Date | Thu, 28 Feb 2019 06:25:22 -0800 |
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On 2/27/19 10:15 PM, Anson Huang wrote: > Hi, Guenter > > Best Regards! > Anson Huang > >> -----Original Message----- >> From: Guenter Roeck [mailto:groeck7@gmail.com] On Behalf Of Guenter >> Roeck >> Sent: 2019年2月27日 6:39 >> To: Anson Huang <anson.huang@nxp.com> >> Cc: robh+dt@kernel.org; mark.rutland@arm.com; shawnguo@kernel.org; >> s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com; >> catalin.marinas@arm.com; will.deacon@arm.com; wim@linux-watchdog.org; >> Aisheng Dong <aisheng.dong@nxp.com>; ulf.hansson@linaro.org; Daniel >> Baluta <daniel.baluta@nxp.com>; Andy Gross <andy.gross@linaro.org>; >> horms+renesas@verge.net.au; heiko@sntech.de; arnd@arndb.de; >> olof@lixom.net; bjorn.andersson@linaro.org; jagan@amarulasolutions.com; >> enric.balletbo@collabora.com; marc.w.gonzalez@free.fr; >> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm- >> kernel@lists.infradead.org; linux-watchdog@vger.kernel.org; dl-linux-imx >> <linux-imx@nxp.com> >> Subject: Re: [PATCH V3 2/4] watchdog: imx_sc: Add i.MX system controller >> watchdog support >> >> On Mon, Feb 25, 2019 at 02:19:10AM +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@nxp.com> >>> --- >>> Changes since V2: >>> - improve watchdog_init_timeout() operation and error check, >> setting it >>> via module parameter "timeout", if it is invalid, roll back to use >> defaul >>> timeout value DEFAULT_TIMEOUT; >>> - change compatible string to "fsl,imx-sc-wdt" to make driver more >> generic >>> for all i.MX platforms with system controller watchdog inside. >>> --- >>> drivers/watchdog/Kconfig | 13 +++ >>> drivers/watchdog/Makefile | 1 + >>> drivers/watchdog/imx_sc_wdt.c | 183 >>> ++++++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 197 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 >> >> Wondering: Did you test on other architectures ? The code calls >> arm_smccc_smc(), which is unlikely to be available on non-ARM platforms, >> and I don't see a dummy declaration for those. > > Although the ARCH_MXC means for Freescale i.MX SoCs which are all with > ARM platforms, but since this driver is targeted for i.MX SoC ARMv8 with system > controller inside, so I will add ARM64 dependency here. > > + depends on (ARCH_MXC && ARM64) || COMPILE_TEST >
You are missing my point. It will still try to compile with, say, alpha:allmodconfig (or x86_64:allmodconfig). Did you try that ?
Guenter
>> >>> + 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..7b22575 >>> --- /dev/null >>> +++ b/drivers/watchdog/imx_sc_wdt.c >>> @@ -0,0 +1,183 @@ >>> +// 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 assume this means that you specifically do _not_ want to support timeout >> configuration via devicetree (unless the user explicitly sets the timeout to 0 >> here). >> >> Not that it really matters, since it looks like Rob won't accept a watchdog >> node anyway. > > Yes, currently we will NOT get it from devicetree, although user can still pass > it via insmod parameter, but if the parameter is NOT specified or is invalid, > default value will be used. > >> >>> +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 res.a0; >> >> I didn't comment on this before, but I am wondering: Does the system >> controller code return Linux error codes ? Is this documented somewhere ? > > I checked our system controller firmware, the ONLY possible error code system controller > returns is SC_ERR_NOACCESS, so I will make it return -EACCES if error happen, for the > ping operation, system controller always returns 0, so I will make it 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 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, }; >>> + >>> +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 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); >> >> I assume this will be dropped and replaced with platform code, per feedback >> from Rob. > > Yes, I will remove it in V4, just register platform device in driver directly. > >> >>> + >>> +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 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@nxp.com>"); >>> +MODULE_DESCRIPTION("NXP i.MX system controller watchdog driver"); >>> +MODULE_LICENSE("GPL v2"); >> >> The module license conflicts with the SPDX license which says 2.0+. > > OK, I will change the SPDX license to 2.0. > > Please help review V4 patch series, the dt-binding and dts patch will be removed. > > Thanks, > Anson. >
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