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Tue, 26 Feb 2019 14:38:47 -0800 (PST) Date: Tue, 26 Feb 2019 14:38:46 -0800 From: Guenter Roeck To: Anson Huang 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 , "ulf.hansson@linaro.org" , Daniel Baluta , Andy Gross , "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 Subject: Re: [PATCH V3 2/4] watchdog: imx_sc: Add i.MX system controller watchdog support Message-ID: <20190226223846.GB30985@roeck-us.net> References: <1551060850-22553-1-git-send-email-Anson.Huang@nxp.com> <1551060850-22553-3-git-send-email-Anson.Huang@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1551060850-22553-3-git-send-email-Anson.Huang@nxp.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org 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 > --- > 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. > + 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 > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#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. > +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 ? > +} > + > +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. > + > +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 "); > +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+.