| Message ID | 1571387622-35132-4-git-send-email-xingyu.chen@amlogic.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | add meson secure watchdog driver | expand |
On 10/18/19 1:33 AM, Xingyu Chen wrote: > The watchdog controller on the Meson-A/C series SoCs is moved to secure > world, watchdog operation needs to be done in secure EL3 mode via ATF, > Non-secure world can call SMC instruction to trap to AFT for watchdog > operation. > > Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com> > --- > drivers/watchdog/Kconfig | 17 ++++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/meson_sec_wdt.c | 187 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 205 insertions(+) > create mode 100644 drivers/watchdog/meson_sec_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 58e7c10..e84be42 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -826,6 +826,23 @@ config MESON_GXBB_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called meson_gxbb_wdt. > > +config MESON_SEC_WATCHDOG > + tristate "Amlogic Meson Secure watchdog support" > + depends on MESON_SM > + depends on ARCH_MESON || COMPILE_TEST This dependency is pointless. MESON_SM already depends on ARCH_MESON, thus specifying "COMPILE_TEST" here adds no value but only creates confusion. > + select WATCHDOG_CORE > + help > + The watchdog controller on the Meson-A/C series SoCs is moved to > + secure world, watchdog operation needs to be done in secure EL3 > + mode via ATF, non-secure world can call SMC instruction to trap > + to ATF for the watchdog operation. > + > + Say Y here if watchdog controller on Meson SoCs is located in > + secure world. > + > + To compile this driver as a module, choose M here: the > + module will be called meson_sec_wdt. > + > config MESON_WATCHDOG > tristate "Amlogic Meson SoCs watchdog support" > depends on ARCH_MESON || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 2ee352b..5e6b73d 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -78,6 +78,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o > obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o > obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o > obj-$(CONFIG_MESON_GXBB_WATCHDOG) += meson_gxbb_wdt.o > +obj-$(CONFIG_MESON_SEC_WATCHDOG) += meson_sec_wdt.o > obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o > obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o > obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o > diff --git a/drivers/watchdog/meson_sec_wdt.c b/drivers/watchdog/meson_sec_wdt.c > new file mode 100644 > index 00000000..86bd87c > --- /dev/null > +++ b/drivers/watchdog/meson_sec_wdt.c > @@ -0,0 +1,187 @@ > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) > +/* > + * Copyright (c) 2019 Amlogic, Inc. All rights reserved. > + * Author: Xingyu Chen <xingyu.chen@amlogic.com> > + * > + */ > +#include <linux/err.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/types.h> > +#include <linux/watchdog.h> > +#include <linux/firmware/meson/meson_sm.h> > + > +#define MESON_SIP_WDT_DISABLE 0x1 > +#define MESON_SIP_WDT_ENABLE 0x2 > +#define MESON_SIP_WDT_PING 0x3 > +#define MESON_SIP_WDT_INIT 0x4 > +#define MESON_SIP_WDT_RESETNOW 0x5 > +#define MESON_SIP_WDT_SETTIMEOUT 0x6 > +#define MESON_SIP_WDT_GETTIMELEFT 0x7 > + > +#define DEFAULT_TIMEOUT 30 /* seconds */ > + > +/* > + * Watchdog timer tick is set to 1ms in secfw side, and tick count is > + * stored in the bit[16-31] of WATCHDOG_CNT register, so the maximum > + * timeout value is 0xffff ms. > + */ > +#define MAX_TIMEOUT_MS 0xFFFF > + > +struct meson_sec_wdt { > + struct watchdog_device wdt_dev; > + struct meson_sm_firmware *fw; > +}; > + > +static int meson_sec_wdt_start(struct watchdog_device *wdt_dev) > +{ > + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); > + > + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, > + MESON_SIP_WDT_ENABLE, 0, 0, 0, 0); > +} > + > +static int meson_sec_wdt_stop(struct watchdog_device *wdt_dev) > +{ > + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); > + > + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, > + MESON_SIP_WDT_DISABLE, 0, 0, 0, 0); > +} > + > +static int meson_sec_wdt_ping(struct watchdog_device *wdt_dev) > +{ > + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); > + > + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, > + MESON_SIP_WDT_PING, 0, 0, 0, 0); > +} > + > +static int meson_sec_wdt_set_timeout(struct watchdog_device *wdt_dev, > + unsigned int timeout) > +{ > + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); > + > + wdt_dev->timeout = timeout; > + > + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, > + MESON_SIP_WDT_SETTIMEOUT, > + wdt_dev->timeout, 0, 0, 0); > +} > + > +static unsigned int meson_sec_wdt_get_timeleft(struct watchdog_device *wdt_dev) > +{ > + int ret; > + unsigned int timeleft; > + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); > + > + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, &timeleft, > + MESON_SIP_WDT_GETTIMELEFT, 0, 0, 0, 0); > + > + if (ret) > + return ret; Meh, that doesn't work. I just realized that the return type is unsigned, so returning a negative error code is pointless. Guess we'll have to live with returning 0 in this case after all. I wonder if we should fix the API and return an integer (with negative error code), but that is a different question. Sorry for the confusion - I should have noticed that before. > + > + return timeleft; > +} > + > +static const struct watchdog_ops meson_sec_wdt_ops = { > + .start = meson_sec_wdt_start, > + .stop = meson_sec_wdt_stop, > + .ping = meson_sec_wdt_ping, > + .set_timeout = meson_sec_wdt_set_timeout, > + .get_timeleft = meson_sec_wdt_get_timeleft, > +}; > + > +static const struct watchdog_info meson_sec_wdt_info = { > + .identity = "Meson Secure Watchdog Timer", > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, > +}; > + > +static int __maybe_unused meson_sec_wdt_resume(struct device *dev) > +{ > + struct meson_sec_wdt *data = dev_get_drvdata(dev); > + > + if (watchdog_active(&data->wdt_dev)) > + return meson_sec_wdt_start(&data->wdt_dev); > + > + return 0; > +} > + > +static int __maybe_unused meson_sec_wdt_suspend(struct device *dev) > +{ > + struct meson_sec_wdt *data = dev_get_drvdata(dev); > + > + if (watchdog_active(&data->wdt_dev)) > + return meson_sec_wdt_stop(&data->wdt_dev); > + > + return 0; > +} > + > +static const struct dev_pm_ops meson_sec_wdt_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(meson_sec_wdt_suspend, meson_sec_wdt_resume) > +}; > + > +static const struct of_device_id meson_sec_wdt_dt_ids[] = { > + { .compatible = "amlogic,meson-sec-wdt", }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, meson_sec_wdt_dt_ids); > + > +static int meson_sec_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct meson_sec_wdt *data; > + struct device_node *sm_np; > + int ret; > + > + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0); > + if (!sm_np) { > + dev_err(&pdev->dev, "no secure-monitor node\n"); > + return -EINVAL; > + } > + > + data->fw = meson_sm_get(sm_np); > + of_node_put(sm_np); > + if (!data->fw) > + return -EPROBE_DEFER; > + > + platform_set_drvdata(pdev, data); > + > + data->wdt_dev.parent = dev; > + data->wdt_dev.info = &meson_sec_wdt_info; > + data->wdt_dev.ops = &meson_sec_wdt_ops; > + data->wdt_dev.max_hw_heartbeat_ms = MAX_TIMEOUT_MS; > + data->wdt_dev.min_timeout = 1; > + data->wdt_dev.timeout = DEFAULT_TIMEOUT; > + watchdog_set_drvdata(&data->wdt_dev, data); > + > + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, > + MESON_SIP_WDT_INIT, > + data->wdt_dev.timeout, 0, 0, 0); > + if (ret) > + return ret; > + > + watchdog_stop_on_reboot(&data->wdt_dev); > + > + return devm_watchdog_register_device(dev, &data->wdt_dev); > +} > + > +static struct platform_driver meson_sec_wdt_driver = { > + .probe = meson_sec_wdt_probe, > + .driver = { > + .name = "meson-sec-wdt", > + .pm = &meson_sec_wdt_pm_ops, > + .of_match_table = meson_sec_wdt_dt_ids, > + }, > +}; > + > +module_platform_driver(meson_sec_wdt_driver); > + > +MODULE_AUTHOR("Xingyu Chen <xingyu.chen@amlogic.com>"); > +MODULE_DESCRIPTION("Amlogic Secure Watchdog Timer Driver"); > +MODULE_LICENSE("Dual MIT/GPL"); >
Hi, Guenter On 2019/10/21 0:56, Guenter Roeck wrote: > On 10/18/19 1:33 AM, Xingyu Chen wrote: >> The watchdog controller on the Meson-A/C series SoCs is moved to secure >> world, watchdog operation needs to be done in secure EL3 mode via ATF, >> Non-secure world can call SMC instruction to trap to AFT for watchdog >> operation. >> >> Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com> >> --- >> drivers/watchdog/Kconfig | 17 ++++ >> drivers/watchdog/Makefile | 1 + >> drivers/watchdog/meson_sec_wdt.c | 187 >> +++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 205 insertions(+) >> create mode 100644 drivers/watchdog/meson_sec_wdt.c >> >> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >> index 58e7c10..e84be42 100644 >> --- a/drivers/watchdog/Kconfig >> +++ b/drivers/watchdog/Kconfig >> @@ -826,6 +826,23 @@ config MESON_GXBB_WATCHDOG >> To compile this driver as a module, choose M here: the >> module will be called meson_gxbb_wdt. >> +config MESON_SEC_WATCHDOG >> + tristate "Amlogic Meson Secure watchdog support" >> + depends on MESON_SM >> + depends on ARCH_MESON || COMPILE_TEST > > This dependency is pointless. MESON_SM already depends on ARCH_MESON, > thus specifying "COMPILE_TEST" here adds no value but only > creates confusion. Thanks for your analysis, perhaps i should remove the line below. - depends on ARCH_MESON || COMPILE_TEST Is it ok to modify code above like this ? > >> + select WATCHDOG_CORE >> + help >> + The watchdog controller on the Meson-A/C series SoCs is moved to >> + secure world, watchdog operation needs to be done in secure EL3 >> + mode via ATF, non-secure world can call SMC instruction to trap >> + to ATF for the watchdog operation. >> + >> + Say Y here if watchdog controller on Meson SoCs is located in >> + secure world. >> + >> + To compile this driver as a module, choose M here: the >> + module will be called meson_sec_wdt. >> + >> config MESON_WATCHDOG >> tristate "Amlogic Meson SoCs watchdog support" >> depends on ARCH_MESON || COMPILE_TEST >> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile >> index 2ee352b..5e6b73d 100644 >> --- a/drivers/watchdog/Makefile >> +++ b/drivers/watchdog/Makefile >> @@ -78,6 +78,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o >> obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o >> obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o >> obj-$(CONFIG_MESON_GXBB_WATCHDOG) += meson_gxbb_wdt.o >> +obj-$(CONFIG_MESON_SEC_WATCHDOG) += meson_sec_wdt.o >> obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o >> obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o >> obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o >> diff --git a/drivers/watchdog/meson_sec_wdt.c >> b/drivers/watchdog/meson_sec_wdt.c >> new file mode 100644 >> index 00000000..86bd87c >> --- /dev/null >> +++ b/drivers/watchdog/meson_sec_wdt.c >> @@ -0,0 +1,187 @@ >> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) >> +/* >> + * Copyright (c) 2019 Amlogic, Inc. All rights reserved. >> + * Author: Xingyu Chen <xingyu.chen@amlogic.com> >> + * >> + */ >> +#include <linux/err.h> >> +#include <linux/module.h> >> +#include <linux/of.h> >> +#include <linux/platform_device.h> >> +#include <linux/types.h> >> +#include <linux/watchdog.h> >> +#include <linux/firmware/meson/meson_sm.h> >> + >> +#define MESON_SIP_WDT_DISABLE 0x1 >> +#define MESON_SIP_WDT_ENABLE 0x2 >> +#define MESON_SIP_WDT_PING 0x3 >> +#define MESON_SIP_WDT_INIT 0x4 >> +#define MESON_SIP_WDT_RESETNOW 0x5 >> +#define MESON_SIP_WDT_SETTIMEOUT 0x6 >> +#define MESON_SIP_WDT_GETTIMELEFT 0x7 >> + >> +#define DEFAULT_TIMEOUT 30 /* seconds */ >> + >> +/* >> + * Watchdog timer tick is set to 1ms in secfw side, and tick count is >> + * stored in the bit[16-31] of WATCHDOG_CNT register, so the maximum >> + * timeout value is 0xffff ms. >> + */ >> +#define MAX_TIMEOUT_MS 0xFFFF >> + >> +struct meson_sec_wdt { >> + struct watchdog_device wdt_dev; >> + struct meson_sm_firmware *fw; >> +}; >> + >> +static int meson_sec_wdt_start(struct watchdog_device *wdt_dev) >> +{ >> + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); >> + >> + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, >> + MESON_SIP_WDT_ENABLE, 0, 0, 0, 0); >> +} >> + >> +static int meson_sec_wdt_stop(struct watchdog_device *wdt_dev) >> +{ >> + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); >> + >> + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, >> + MESON_SIP_WDT_DISABLE, 0, 0, 0, 0); >> +} >> + >> +static int meson_sec_wdt_ping(struct watchdog_device *wdt_dev) >> +{ >> + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); >> + >> + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, >> + MESON_SIP_WDT_PING, 0, 0, 0, 0); >> +} >> + >> +static int meson_sec_wdt_set_timeout(struct watchdog_device *wdt_dev, >> + unsigned int timeout) >> +{ >> + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); >> + >> + wdt_dev->timeout = timeout; >> + >> + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, >> + MESON_SIP_WDT_SETTIMEOUT, >> + wdt_dev->timeout, 0, 0, 0); >> +} >> + >> +static unsigned int meson_sec_wdt_get_timeleft(struct watchdog_device >> *wdt_dev) >> +{ >> + int ret; >> + unsigned int timeleft; >> + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); >> + >> + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, &timeleft, >> + MESON_SIP_WDT_GETTIMELEFT, 0, 0, 0, 0); >> + >> + if (ret) >> + return ret; > > Meh, that doesn't work. I just realized that the return type is unsigned, > so returning a negative error code is pointless. Guess we'll have to > live with returning 0 in this case after all. I wonder if we should > fix the API and return an integer (with negative error code), but that > is a different question. Thanks for your review. IMO, if returning an integer, and the value which copy to user buf should be formatted with %d instead of %u (see timeleft_show), it will cause the max value of timeleft is reduced from 4294967295 to 2147483647. but i'am not sure whether it will bring risk. So i also think returning 0 may be better in this case. > > Sorry for the confusion - I should have noticed that before. > >> + >> + return timeleft; >> +} >> + >> +static const struct watchdog_ops meson_sec_wdt_ops = { >> + .start = meson_sec_wdt_start, >> + .stop = meson_sec_wdt_stop, >> + .ping = meson_sec_wdt_ping, >> + .set_timeout = meson_sec_wdt_set_timeout, >> + .get_timeleft = meson_sec_wdt_get_timeleft, >> +}; >> + >> +static const struct watchdog_info meson_sec_wdt_info = { >> + .identity = "Meson Secure Watchdog Timer", >> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | >> WDIOF_MAGICCLOSE, >> +}; >> + >> +static int __maybe_unused meson_sec_wdt_resume(struct device *dev) >> +{ >> + struct meson_sec_wdt *data = dev_get_drvdata(dev); >> + >> + if (watchdog_active(&data->wdt_dev)) >> + return meson_sec_wdt_start(&data->wdt_dev); >> + >> + return 0; >> +} >> + >> +static int __maybe_unused meson_sec_wdt_suspend(struct device *dev) >> +{ >> + struct meson_sec_wdt *data = dev_get_drvdata(dev); >> + >> + if (watchdog_active(&data->wdt_dev)) >> + return meson_sec_wdt_stop(&data->wdt_dev); >> + >> + return 0; >> +} >> + >> +static const struct dev_pm_ops meson_sec_wdt_pm_ops = { >> + SET_SYSTEM_SLEEP_PM_OPS(meson_sec_wdt_suspend, meson_sec_wdt_resume) >> +}; >> + >> +static const struct of_device_id meson_sec_wdt_dt_ids[] = { >> + { .compatible = "amlogic,meson-sec-wdt", }, >> + { /* sentinel */ }, >> +}; >> +MODULE_DEVICE_TABLE(of, meson_sec_wdt_dt_ids); >> + >> +static int meson_sec_wdt_probe(struct platform_device *pdev) >> +{ >> + struct device *dev = &pdev->dev; >> + struct meson_sec_wdt *data; >> + struct device_node *sm_np; >> + int ret; >> + >> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); >> + if (!data) >> + return -ENOMEM; >> + >> + sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0); >> + if (!sm_np) { >> + dev_err(&pdev->dev, "no secure-monitor node\n"); >> + return -EINVAL; >> + } >> + >> + data->fw = meson_sm_get(sm_np); >> + of_node_put(sm_np); >> + if (!data->fw) >> + return -EPROBE_DEFER; >> + >> + platform_set_drvdata(pdev, data); >> + >> + data->wdt_dev.parent = dev; >> + data->wdt_dev.info = &meson_sec_wdt_info; >> + data->wdt_dev.ops = &meson_sec_wdt_ops; >> + data->wdt_dev.max_hw_heartbeat_ms = MAX_TIMEOUT_MS; >> + data->wdt_dev.min_timeout = 1; >> + data->wdt_dev.timeout = DEFAULT_TIMEOUT; >> + watchdog_set_drvdata(&data->wdt_dev, data); >> + >> + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, >> + MESON_SIP_WDT_INIT, >> + data->wdt_dev.timeout, 0, 0, 0); >> + if (ret) >> + return ret; >> + >> + watchdog_stop_on_reboot(&data->wdt_dev); >> + >> + return devm_watchdog_register_device(dev, &data->wdt_dev); >> +} >> + >> +static struct platform_driver meson_sec_wdt_driver = { >> + .probe = meson_sec_wdt_probe, >> + .driver = { >> + .name = "meson-sec-wdt", >> + .pm = &meson_sec_wdt_pm_ops, >> + .of_match_table = meson_sec_wdt_dt_ids, >> + }, >> +}; >> + >> +module_platform_driver(meson_sec_wdt_driver); >> + >> +MODULE_AUTHOR("Xingyu Chen <xingyu.chen@amlogic.com>"); >> +MODULE_DESCRIPTION("Amlogic Secure Watchdog Timer Driver"); >> +MODULE_LICENSE("Dual MIT/GPL"); >> > > . >
On 10/21/19 1:03 AM, Xingyu Chen wrote: > Hi, Guenter > > On 2019/10/21 0:56, Guenter Roeck wrote: >> On 10/18/19 1:33 AM, Xingyu Chen wrote: >>> The watchdog controller on the Meson-A/C series SoCs is moved to secure >>> world, watchdog operation needs to be done in secure EL3 mode via ATF, >>> Non-secure world can call SMC instruction to trap to AFT for watchdog >>> operation. >>> >>> Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com> >>> --- >>> drivers/watchdog/Kconfig | 17 ++++ >>> drivers/watchdog/Makefile | 1 + >>> drivers/watchdog/meson_sec_wdt.c | 187 +++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 205 insertions(+) >>> create mode 100644 drivers/watchdog/meson_sec_wdt.c >>> >>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >>> index 58e7c10..e84be42 100644 >>> --- a/drivers/watchdog/Kconfig >>> +++ b/drivers/watchdog/Kconfig >>> @@ -826,6 +826,23 @@ config MESON_GXBB_WATCHDOG >>> To compile this driver as a module, choose M here: the >>> module will be called meson_gxbb_wdt. >>> +config MESON_SEC_WATCHDOG >>> + tristate "Amlogic Meson Secure watchdog support" >>> + depends on MESON_SM >>> + depends on ARCH_MESON || COMPILE_TEST >> >> This dependency is pointless. MESON_SM already depends on ARCH_MESON, >> thus specifying "COMPILE_TEST" here adds no value but only >> creates confusion. > Thanks for your analysis, perhaps i should remove the line below. > - depends on ARCH_MESON || COMPILE_TEST > > Is it ok to modify code above like this ? Yes. [ ... ] >>> +static unsigned int meson_sec_wdt_get_timeleft(struct watchdog_device *wdt_dev) >>> +{ >>> + int ret; >>> + unsigned int timeleft; >>> + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); >>> + >>> + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, &timeleft, >>> + MESON_SIP_WDT_GETTIMELEFT, 0, 0, 0, 0); >>> + >>> + if (ret) >>> + return ret; >> >> Meh, that doesn't work. I just realized that the return type is unsigned, >> so returning a negative error code is pointless. Guess we'll have to >> live with returning 0 in this case after all. I wonder if we should >> fix the API and return an integer (with negative error code), but that >> is a different question. > Thanks for your review. > > IMO, if returning an integer, and the value which copy to user buf should be formatted with %d instead of %u (see timeleft_show), it will cause the max value of timeleft is reduced from 4294967295 to 2147483647. but i'am not sure whether it will bring risk. Not that it matters right now, but I don't think that limiting 'timeleft' reporting to 2147483647 seconds, or ~68 years, would cause any risk. It would just be a large patch changing several drivers all at once, that is all. > > So i also think returning 0 may be better in this case. Yes, please do that. Thanks, Guenter
Hi, Guenter On 2019/10/21 21:38, Guenter Roeck wrote: > On 10/21/19 1:03 AM, Xingyu Chen wrote: >> Hi, Guenter >> >> On 2019/10/21 0:56, Guenter Roeck wrote: >>> On 10/18/19 1:33 AM, Xingyu Chen wrote: >>>> The watchdog controller on the Meson-A/C series SoCs is moved to secure >>>> world, watchdog operation needs to be done in secure EL3 mode via ATF, >>>> Non-secure world can call SMC instruction to trap to AFT for watchdog >>>> operation. >>>> >>>> Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com> >>>> --- >>>> drivers/watchdog/Kconfig | 17 ++++ >>>> drivers/watchdog/Makefile | 1 + >>>> drivers/watchdog/meson_sec_wdt.c | 187 >>>> +++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 205 insertions(+) >>>> create mode 100644 drivers/watchdog/meson_sec_wdt.c >>>> >>>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >>>> index 58e7c10..e84be42 100644 >>>> --- a/drivers/watchdog/Kconfig >>>> +++ b/drivers/watchdog/Kconfig >>>> @@ -826,6 +826,23 @@ config MESON_GXBB_WATCHDOG >>>> To compile this driver as a module, choose M here: the >>>> module will be called meson_gxbb_wdt. >>>> +config MESON_SEC_WATCHDOG >>>> + tristate "Amlogic Meson Secure watchdog support" >>>> + depends on MESON_SM >>>> + depends on ARCH_MESON || COMPILE_TEST >>> >>> This dependency is pointless. MESON_SM already depends on ARCH_MESON, >>> thus specifying "COMPILE_TEST" here adds no value but only >>> creates confusion. >> Thanks for your analysis, perhaps i should remove the line below. >> - depends on ARCH_MESON || COMPILE_TEST >> >> Is it ok to modify code above like this ? > > Yes. Thanks, fix it in next version. > [ ... ] > >>>> +static unsigned int meson_sec_wdt_get_timeleft(struct >>>> watchdog_device *wdt_dev) >>>> +{ >>>> + int ret; >>>> + unsigned int timeleft; >>>> + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); >>>> + >>>> + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, Thanks&timeleft, >>>> + MESON_SIP_WDT_GETTIMELEFT, 0, 0, 0, 0); >>>> + >>>> + if (ret) >>>> + return ret; >>> >>> Meh, that doesn't work. I just realized that the return type is >>> unsigned, >>> so returning a negative error code is pointless. Guess we'll have to >>> live with returning 0 in this case after all. I wonder if we should >>> fix the API and return an integer (with negative error code), but that >>> is a different question. >> Thanks for your review. >> >> IMO, if returning an integer, and the value which copy to user buf >> should be formatted with %d instead of %u (see timeleft_show), it will >> cause the max value of timeleft is reduced from 4294967295 to >> 2147483647. but i'am not sure whether it will bring risk. > > Not that it matters right now, but I don't think that limiting 'timeleft' > reporting to 2147483647 seconds, or ~68 years, would cause any risk. > It would just be a large patch changing several drivers all at once, > that is all. > >> >> So i also think returning 0 may be better in this case. > > Yes, please do that. Thanks, fix it in next version. > > Thanks, > Guenter > > . >
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 58e7c10..e84be42 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -826,6 +826,23 @@ config MESON_GXBB_WATCHDOG To compile this driver as a module, choose M here: the module will be called meson_gxbb_wdt. +config MESON_SEC_WATCHDOG + tristate "Amlogic Meson Secure watchdog support" + depends on MESON_SM + depends on ARCH_MESON || COMPILE_TEST + select WATCHDOG_CORE + help + The watchdog controller on the Meson-A/C series SoCs is moved to + secure world, watchdog operation needs to be done in secure EL3 + mode via ATF, non-secure world can call SMC instruction to trap + to ATF for the watchdog operation. + + Say Y here if watchdog controller on Meson SoCs is located in + secure world. + + To compile this driver as a module, choose M here: the + module will be called meson_sec_wdt. + config MESON_WATCHDOG tristate "Amlogic Meson SoCs watchdog support" depends on ARCH_MESON || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2ee352b..5e6b73d 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -78,6 +78,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o obj-$(CONFIG_MESON_GXBB_WATCHDOG) += meson_gxbb_wdt.o +obj-$(CONFIG_MESON_SEC_WATCHDOG) += meson_sec_wdt.o obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o diff --git a/drivers/watchdog/meson_sec_wdt.c b/drivers/watchdog/meson_sec_wdt.c new file mode 100644 index 00000000..86bd87c --- /dev/null +++ b/drivers/watchdog/meson_sec_wdt.c @@ -0,0 +1,187 @@ +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) +/* + * Copyright (c) 2019 Amlogic, Inc. All rights reserved. + * Author: Xingyu Chen <xingyu.chen@amlogic.com> + * + */ +#include <linux/err.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/types.h> +#include <linux/watchdog.h> +#include <linux/firmware/meson/meson_sm.h> + +#define MESON_SIP_WDT_DISABLE 0x1 +#define MESON_SIP_WDT_ENABLE 0x2 +#define MESON_SIP_WDT_PING 0x3 +#define MESON_SIP_WDT_INIT 0x4 +#define MESON_SIP_WDT_RESETNOW 0x5 +#define MESON_SIP_WDT_SETTIMEOUT 0x6 +#define MESON_SIP_WDT_GETTIMELEFT 0x7 + +#define DEFAULT_TIMEOUT 30 /* seconds */ + +/* + * Watchdog timer tick is set to 1ms in secfw side, and tick count is + * stored in the bit[16-31] of WATCHDOG_CNT register, so the maximum + * timeout value is 0xffff ms. + */ +#define MAX_TIMEOUT_MS 0xFFFF + +struct meson_sec_wdt { + struct watchdog_device wdt_dev; + struct meson_sm_firmware *fw; +}; + +static int meson_sec_wdt_start(struct watchdog_device *wdt_dev) +{ + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); + + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, + MESON_SIP_WDT_ENABLE, 0, 0, 0, 0); +} + +static int meson_sec_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); + + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, + MESON_SIP_WDT_DISABLE, 0, 0, 0, 0); +} + +static int meson_sec_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); + + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, + MESON_SIP_WDT_PING, 0, 0, 0, 0); +} + +static int meson_sec_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int timeout) +{ + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); + + wdt_dev->timeout = timeout; + + return meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, + MESON_SIP_WDT_SETTIMEOUT, + wdt_dev->timeout, 0, 0, 0); +} + +static unsigned int meson_sec_wdt_get_timeleft(struct watchdog_device *wdt_dev) +{ + int ret; + unsigned int timeleft; + struct meson_sec_wdt *data = watchdog_get_drvdata(wdt_dev); + + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, &timeleft, + MESON_SIP_WDT_GETTIMELEFT, 0, 0, 0, 0); + + if (ret) + return ret; + + return timeleft; +} + +static const struct watchdog_ops meson_sec_wdt_ops = { + .start = meson_sec_wdt_start, + .stop = meson_sec_wdt_stop, + .ping = meson_sec_wdt_ping, + .set_timeout = meson_sec_wdt_set_timeout, + .get_timeleft = meson_sec_wdt_get_timeleft, +}; + +static const struct watchdog_info meson_sec_wdt_info = { + .identity = "Meson Secure Watchdog Timer", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; + +static int __maybe_unused meson_sec_wdt_resume(struct device *dev) +{ + struct meson_sec_wdt *data = dev_get_drvdata(dev); + + if (watchdog_active(&data->wdt_dev)) + return meson_sec_wdt_start(&data->wdt_dev); + + return 0; +} + +static int __maybe_unused meson_sec_wdt_suspend(struct device *dev) +{ + struct meson_sec_wdt *data = dev_get_drvdata(dev); + + if (watchdog_active(&data->wdt_dev)) + return meson_sec_wdt_stop(&data->wdt_dev); + + return 0; +} + +static const struct dev_pm_ops meson_sec_wdt_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(meson_sec_wdt_suspend, meson_sec_wdt_resume) +}; + +static const struct of_device_id meson_sec_wdt_dt_ids[] = { + { .compatible = "amlogic,meson-sec-wdt", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, meson_sec_wdt_dt_ids); + +static int meson_sec_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct meson_sec_wdt *data; + struct device_node *sm_np; + int ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + sm_np = of_parse_phandle(pdev->dev.of_node, "secure-monitor", 0); + if (!sm_np) { + dev_err(&pdev->dev, "no secure-monitor node\n"); + return -EINVAL; + } + + data->fw = meson_sm_get(sm_np); + of_node_put(sm_np); + if (!data->fw) + return -EPROBE_DEFER; + + platform_set_drvdata(pdev, data); + + data->wdt_dev.parent = dev; + data->wdt_dev.info = &meson_sec_wdt_info; + data->wdt_dev.ops = &meson_sec_wdt_ops; + data->wdt_dev.max_hw_heartbeat_ms = MAX_TIMEOUT_MS; + data->wdt_dev.min_timeout = 1; + data->wdt_dev.timeout = DEFAULT_TIMEOUT; + watchdog_set_drvdata(&data->wdt_dev, data); + + ret = meson_sm_call(data->fw, SM_WATCHDOG_OPS, NULL, + MESON_SIP_WDT_INIT, + data->wdt_dev.timeout, 0, 0, 0); + if (ret) + return ret; + + watchdog_stop_on_reboot(&data->wdt_dev); + + return devm_watchdog_register_device(dev, &data->wdt_dev); +} + +static struct platform_driver meson_sec_wdt_driver = { + .probe = meson_sec_wdt_probe, + .driver = { + .name = "meson-sec-wdt", + .pm = &meson_sec_wdt_pm_ops, + .of_match_table = meson_sec_wdt_dt_ids, + }, +}; + +module_platform_driver(meson_sec_wdt_driver); + +MODULE_AUTHOR("Xingyu Chen <xingyu.chen@amlogic.com>"); +MODULE_DESCRIPTION("Amlogic Secure Watchdog Timer Driver"); +MODULE_LICENSE("Dual MIT/GPL");
The watchdog controller on the Meson-A/C series SoCs is moved to secure world, watchdog operation needs to be done in secure EL3 mode via ATF, Non-secure world can call SMC instruction to trap to AFT for watchdog operation. Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com> --- drivers/watchdog/Kconfig | 17 ++++ drivers/watchdog/Makefile | 1 + drivers/watchdog/meson_sec_wdt.c | 187 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 205 insertions(+) create mode 100644 drivers/watchdog/meson_sec_wdt.c