* [PATCH v2 0/2] rtc: provide an emulated RTC
@ 2020-10-25 7:13 Heinrich Schuchardt
2020-10-25 7:13 ` [PATCH v2 1/2] Makefile: provide constant with seconds since epoch Heinrich Schuchardt
` (2 more replies)
0 siblings, 3 replies; 10+ messages in thread
From: Heinrich Schuchardt @ 2020-10-25 7:13 UTC (permalink / raw)
To: u-boot
On a board without hardware clock this software real time clock can be
used. The build time is used to initialize the RTC. So you will have
to adjust the time either manually using the 'date' command or use
the 'sntp' to update the RTC with the time from a network time server.
See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
advanced according to CPU ticks.
v2:
more elaborate Kconfig message
adjust device name properties
use build time as initial time
Heinrich Schuchardt (2):
Makefile: provide constant with seconds since epoch
rtc: provide an emulated RTC
MAINTAINERS | 1 +
Makefile | 2 ++
drivers/rtc/Kconfig | 11 ++++++
drivers/rtc/Makefile | 1 +
drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
5 files changed, 95 insertions(+)
create mode 100644 drivers/rtc/emul_rtc.c
--
2.28.0
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 1/2] Makefile: provide constant with seconds since epoch
2020-10-25 7:13 [PATCH v2 0/2] rtc: provide an emulated RTC Heinrich Schuchardt
@ 2020-10-25 7:13 ` Heinrich Schuchardt
2020-10-27 4:52 ` Simon Glass
2020-10-25 7:13 ` [PATCH v2 2/2] rtc: provide an emulated RTC Heinrich Schuchardt
2020-10-29 10:27 ` [PATCH v2 0/2] " Pablo Sebastián Greco
2 siblings, 1 reply; 10+ messages in thread
From: Heinrich Schuchardt @ 2020-10-25 7:13 UTC (permalink / raw)
To: u-boot
Provide a constant U_BOOT_EPOCH with the number of seconds since
1970-01-01. This constant can be used to initialize a software
real time clock until it is updated via the 'sntp' command.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
v2:
new patch
---
Makefile | 2 ++
1 file changed, 2 insertions(+)
diff --git a/Makefile b/Makefile
index 5a0ef18668..c21729cf52 100644
--- a/Makefile
+++ b/Makefile
@@ -1870,6 +1870,7 @@ define filechk_timestamp.h
LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_TZ "%z"'; \
LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_DMI_DATE "%m/%d/%Y"'; \
LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_BUILD_DATE 0x%Y%m%d'; \
+ LC_ALL=C $${DATE} -u -d "$${SOURCE_DATE}" +'#define U_BOOT_EPOCH %s'; \
else \
return 42; \
fi; \
@@ -1879,6 +1880,7 @@ define filechk_timestamp.h
LC_ALL=C date +'#define U_BOOT_TZ "%z"'; \
LC_ALL=C date +'#define U_BOOT_DMI_DATE "%m/%d/%Y"'; \
LC_ALL=C date +'#define U_BOOT_BUILD_DATE 0x%Y%m%d'; \
+ LC_ALL=C date +'#define U_BOOT_EPOCH %s'; \
fi)
endef
--
2.28.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 2/2] rtc: provide an emulated RTC
2020-10-25 7:13 [PATCH v2 0/2] rtc: provide an emulated RTC Heinrich Schuchardt
2020-10-25 7:13 ` [PATCH v2 1/2] Makefile: provide constant with seconds since epoch Heinrich Schuchardt
@ 2020-10-25 7:13 ` Heinrich Schuchardt
2020-10-26 15:30 ` Grant Likely
2020-10-27 4:52 ` Simon Glass
2020-10-29 10:27 ` [PATCH v2 0/2] " Pablo Sebastián Greco
2 siblings, 2 replies; 10+ messages in thread
From: Heinrich Schuchardt @ 2020-10-25 7:13 UTC (permalink / raw)
To: u-boot
On a board without hardware clock this software real time clock can be
used. The build time is used to initialize the RTC. So you will have
to adjust the time either manually using the 'date' command or use
the 'sntp' to update the RTC with the time from a network time server.
See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
advanced according to CPU ticks.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
v2:
more elaborate Kconfig message
adjust device name properties
use build time as initial time
---
MAINTAINERS | 1 +
drivers/rtc/Kconfig | 11 ++++++
drivers/rtc/Makefile | 1 +
drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 93 insertions(+)
create mode 100644 drivers/rtc/emul_rtc.c
diff --git a/MAINTAINERS b/MAINTAINERS
index fc4fad46ee..a98e0c5b76 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -678,6 +678,7 @@ S: Maintained
T: git https://gitlab.denx.de/u-boot/custodians/u-boot-efi.git
F: doc/api/efi.rst
F: doc/uefi/*
+F: drivers/rtc/emul_rtc.c
F: include/capitalization.h
F: include/charset.h
F: include/cp1250.h
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 63662001c2..d06d272e14 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -63,6 +63,17 @@ config RTC_DS3232
Support for Dallas Semiconductor (now Maxim) DS3232 compatible
Real Time Clock devices.
+config RTC_EMULATION
+ bool "Enable emulated RTC"
+ depends on DM_RTC
+ help
+ On a board without hardware clock this software real time clock can be
+ used. The build time is used to initialize the RTC. So you will have
+ to adjust the time either manually using the 'date' command or use
+ the 'sntp' to update the RTC with the time from a network time server.
+ See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
+ advanced according to CPU ticks.
+
config RTC_ISL1208
bool "Enable ISL1208 driver"
depends on DM_RTC
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 12eb449583..ef66dc4bf0 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_RTC_DS164x) += ds164x.o
obj-$(CONFIG_RTC_DS174x) += ds174x.o
obj-$(CONFIG_RTC_DS3231) += ds3231.o
obj-$(CONFIG_RTC_DS3232) += ds3232.o
+obj-$(CONFIG_RTC_EMULATION) += emul_rtc.o
obj-$(CONFIG_RTC_FTRTC010) += ftrtc010.o
obj-$(CONFIG_SANDBOX) += i2c_rtc_emul.o
obj-$(CONFIG_RTC_IMXDI) += imxdi.o
diff --git a/drivers/rtc/emul_rtc.c b/drivers/rtc/emul_rtc.c
new file mode 100644
index 0000000000..c98c24bbb3
--- /dev/null
+++ b/drivers/rtc/emul_rtc.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
+ *
+ * This driver emulates a real time clock based on timer ticks.
+ */
+
+#include <common.h>
+#include <div64.h>
+#include <dm.h>
+#include <generated/timestamp_autogenerated.h>
+#include <rtc.h>
+
+/**
+ * struct emul_rtc - private data for emulated RTC driver
+ */
+struct emul_rtc {
+ /**
+ * @offset_us: microseconds from 1970-01-01 to timer_get_us() base
+ */
+ u64 offset_us;
+ /**
+ * @isdst: daylight saving time
+ */
+ int isdst;
+};
+
+static int emul_rtc_get(struct udevice *dev, struct rtc_time *time)
+{
+ struct emul_rtc *priv = dev_get_priv(dev);
+ u64 now;
+
+ if (!priv->offset_us) {
+ /* Use the build date as initial time */
+ priv->offset_us = U_BOOT_EPOCH * 1000000ULL - timer_get_us();
+ priv->isdst = -1;
+ }
+
+ now = timer_get_us() + priv->offset_us;
+ do_div(now, 1000000);
+ rtc_to_tm(now, time);
+ time->tm_isdst = priv->isdst;
+
+ return 0;
+}
+
+static int emul_rtc_set(struct udevice *dev, const struct rtc_time *time)
+{
+ struct emul_rtc *priv = dev_get_priv(dev);
+
+ if (time->tm_year < 1970)
+ return -EINVAL;
+
+ priv->offset_us = rtc_mktime(time) * 1000000ULL - timer_get_us();
+
+ if (time->tm_isdst > 0)
+ priv->isdst = 1;
+ else if (time->tm_isdst < 0)
+ priv->isdst = -1;
+ else
+ priv->isdst = 0;
+
+ return 0;
+}
+
+static const struct rtc_ops emul_rtc_ops = {
+ .get = emul_rtc_get,
+ .set = emul_rtc_set,
+};
+
+U_BOOT_DRIVER(rtc_emul) = {
+ .name = "rtc_emul",
+ .id = UCLASS_RTC,
+ .ops = &emul_rtc_ops,
+ .priv_auto_alloc_size = sizeof(struct emul_rtc),
+};
+
+U_BOOT_DEVICE(rtc_emul) = {
+ .name = "rtc_emul",
+};
--
2.28.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 2/2] rtc: provide an emulated RTC
2020-10-25 7:13 ` [PATCH v2 2/2] rtc: provide an emulated RTC Heinrich Schuchardt
@ 2020-10-26 15:30 ` Grant Likely
[not found] ` <CACxGe6uz2_cysTuPC6zZRiTLkPCHbz6+9edqMzktQB3orY1R5w@mail.gmail.com>
2020-10-27 4:52 ` Simon Glass
1 sibling, 1 reply; 10+ messages in thread
From: Grant Likely @ 2020-10-26 15:30 UTC (permalink / raw)
To: u-boot
On Sun, Oct 25, 2020 at 7:13 AM Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>
> On a board without hardware clock this software real time clock can be
> used. The build time is used to initialize the RTC. So you will have
> to adjust the time either manually using the 'date' command or use
> the 'sntp' to update the RTC with the time from a network time server.
> See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
> advanced according to CPU ticks.
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Looks good to me, and tested on RockPro64 w/ UEFI SCT.
Tested-by: Grant Likely <grant.likely@arm.com>
g.
> ---
> v2:
> more elaborate Kconfig message
> adjust device name properties
> use build time as initial time
> ---
> MAINTAINERS | 1 +
> drivers/rtc/Kconfig | 11 ++++++
> drivers/rtc/Makefile | 1 +
> drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 93 insertions(+)
> create mode 100644 drivers/rtc/emul_rtc.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index fc4fad46ee..a98e0c5b76 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -678,6 +678,7 @@ S: Maintained
> T: git https://gitlab.denx.de/u-boot/custodians/u-boot-efi.git
> F: doc/api/efi.rst
> F: doc/uefi/*
> +F: drivers/rtc/emul_rtc.c
> F: include/capitalization.h
> F: include/charset.h
> F: include/cp1250.h
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 63662001c2..d06d272e14 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -63,6 +63,17 @@ config RTC_DS3232
> Support for Dallas Semiconductor (now Maxim) DS3232 compatible
> Real Time Clock devices.
>
> +config RTC_EMULATION
> + bool "Enable emulated RTC"
> + depends on DM_RTC
> + help
> + On a board without hardware clock this software real time clock can be
> + used. The build time is used to initialize the RTC. So you will have
> + to adjust the time either manually using the 'date' command or use
> + the 'sntp' to update the RTC with the time from a network time server.
> + See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
> + advanced according to CPU ticks.
> +
> config RTC_ISL1208
> bool "Enable ISL1208 driver"
> depends on DM_RTC
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 12eb449583..ef66dc4bf0 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_RTC_DS164x) += ds164x.o
> obj-$(CONFIG_RTC_DS174x) += ds174x.o
> obj-$(CONFIG_RTC_DS3231) += ds3231.o
> obj-$(CONFIG_RTC_DS3232) += ds3232.o
> +obj-$(CONFIG_RTC_EMULATION) += emul_rtc.o
> obj-$(CONFIG_RTC_FTRTC010) += ftrtc010.o
> obj-$(CONFIG_SANDBOX) += i2c_rtc_emul.o
> obj-$(CONFIG_RTC_IMXDI) += imxdi.o
> diff --git a/drivers/rtc/emul_rtc.c b/drivers/rtc/emul_rtc.c
> new file mode 100644
> index 0000000000..c98c24bbb3
> --- /dev/null
> +++ b/drivers/rtc/emul_rtc.c
> @@ -0,0 +1,80 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
> + *
> + * This driver emulates a real time clock based on timer ticks.
> + */
> +
> +#include <common.h>
> +#include <div64.h>
> +#include <dm.h>
> +#include <generated/timestamp_autogenerated.h>
> +#include <rtc.h>
> +
> +/**
> + * struct emul_rtc - private data for emulated RTC driver
> + */
> +struct emul_rtc {
> + /**
> + * @offset_us: microseconds from 1970-01-01 to timer_get_us() base
> + */
> + u64 offset_us;
> + /**
> + * @isdst: daylight saving time
> + */
> + int isdst;
> +};
> +
> +static int emul_rtc_get(struct udevice *dev, struct rtc_time *time)
> +{
> + struct emul_rtc *priv = dev_get_priv(dev);
> + u64 now;
> +
> + if (!priv->offset_us) {
> + /* Use the build date as initial time */
> + priv->offset_us = U_BOOT_EPOCH * 1000000ULL - timer_get_us();
> + priv->isdst = -1;
> + }
> +
> + now = timer_get_us() + priv->offset_us;
> + do_div(now, 1000000);
> + rtc_to_tm(now, time);
> + time->tm_isdst = priv->isdst;
> +
> + return 0;
> +}
> +
> +static int emul_rtc_set(struct udevice *dev, const struct rtc_time *time)
> +{
> + struct emul_rtc *priv = dev_get_priv(dev);
> +
> + if (time->tm_year < 1970)
> + return -EINVAL;
> +
> + priv->offset_us = rtc_mktime(time) * 1000000ULL - timer_get_us();
> +
> + if (time->tm_isdst > 0)
> + priv->isdst = 1;
> + else if (time->tm_isdst < 0)
> + priv->isdst = -1;
> + else
> + priv->isdst = 0;
> +
> + return 0;
> +}
> +
> +static const struct rtc_ops emul_rtc_ops = {
> + .get = emul_rtc_get,
> + .set = emul_rtc_set,
> +};
> +
> +U_BOOT_DRIVER(rtc_emul) = {
> + .name = "rtc_emul",
> + .id = UCLASS_RTC,
> + .ops = &emul_rtc_ops,
> + .priv_auto_alloc_size = sizeof(struct emul_rtc),
> +};
> +
> +U_BOOT_DEVICE(rtc_emul) = {
> + .name = "rtc_emul",
> +};
> --
> 2.28.0
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 2/2] rtc: provide an emulated RTC
[not found] ` <CACxGe6uz2_cysTuPC6zZRiTLkPCHbz6+9edqMzktQB3orY1R5w@mail.gmail.com>
@ 2020-10-26 19:18 ` Heinrich Schuchardt
0 siblings, 0 replies; 10+ messages in thread
From: Heinrich Schuchardt @ 2020-10-26 19:18 UTC (permalink / raw)
To: u-boot
On 26.10.20 16:31, Grant Likely wrote:
> On Mon, Oct 26, 2020 at 3:30 PM Grant Likely <grant.likely@secretlab.ca> wrote:
>>
>> On Sun, Oct 25, 2020 at 7:13 AM Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>>>
>>> On a board without hardware clock this software real time clock can be
>>> used. The build time is used to initialize the RTC. So you will have
>>> to adjust the time either manually using the 'date' command or use
>>> the 'sntp' to update the RTC with the time from a network time server.
>>> See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
>>> advanced according to CPU ticks.
>>>
>>> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
>>
>> Looks good to me, and tested on RockPro64 w/ UEFI SCT.
>>
>> Tested-by: Grant Likely <grant.likely@arm.com>
>
> One thought: Can this be automatically enabled if no other RTC driver
> is configured in?
* This RTC does not show the correct time unless you use SNTP to set it.
* There is no need for an RTC to boot an OS.
* Many board maintainers struggle with the size of there U-Boot binary.
So it does not make sense to me to enable this driver as fallback by
default.
Best regards
Heinrich
>
> g.
>
>>
>> g.
>>
>>> ---
>>> v2:
>>> more elaborate Kconfig message
>>> adjust device name properties
>>> use build time as initial time
>>> ---
>>> MAINTAINERS | 1 +
>>> drivers/rtc/Kconfig | 11 ++++++
>>> drivers/rtc/Makefile | 1 +
>>> drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
>>> 4 files changed, 93 insertions(+)
>>> create mode 100644 drivers/rtc/emul_rtc.c
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index fc4fad46ee..a98e0c5b76 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -678,6 +678,7 @@ S: Maintained
>>> T: git https://gitlab.denx.de/u-boot/custodians/u-boot-efi.git
>>> F: doc/api/efi.rst
>>> F: doc/uefi/*
>>> +F: drivers/rtc/emul_rtc.c
>>> F: include/capitalization.h
>>> F: include/charset.h
>>> F: include/cp1250.h
>>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>>> index 63662001c2..d06d272e14 100644
>>> --- a/drivers/rtc/Kconfig
>>> +++ b/drivers/rtc/Kconfig
>>> @@ -63,6 +63,17 @@ config RTC_DS3232
>>> Support for Dallas Semiconductor (now Maxim) DS3232 compatible
>>> Real Time Clock devices.
>>>
>>> +config RTC_EMULATION
>>> + bool "Enable emulated RTC"
>>> + depends on DM_RTC
>>> + help
>>> + On a board without hardware clock this software real time clock can be
>>> + used. The build time is used to initialize the RTC. So you will have
>>> + to adjust the time either manually using the 'date' command or use
>>> + the 'sntp' to update the RTC with the time from a network time server.
>>> + See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
>>> + advanced according to CPU ticks.
>>> +
>>> config RTC_ISL1208
>>> bool "Enable ISL1208 driver"
>>> depends on DM_RTC
>>> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
>>> index 12eb449583..ef66dc4bf0 100644
>>> --- a/drivers/rtc/Makefile
>>> +++ b/drivers/rtc/Makefile
>>> @@ -22,6 +22,7 @@ obj-$(CONFIG_RTC_DS164x) += ds164x.o
>>> obj-$(CONFIG_RTC_DS174x) += ds174x.o
>>> obj-$(CONFIG_RTC_DS3231) += ds3231.o
>>> obj-$(CONFIG_RTC_DS3232) += ds3232.o
>>> +obj-$(CONFIG_RTC_EMULATION) += emul_rtc.o
>>> obj-$(CONFIG_RTC_FTRTC010) += ftrtc010.o
>>> obj-$(CONFIG_SANDBOX) += i2c_rtc_emul.o
>>> obj-$(CONFIG_RTC_IMXDI) += imxdi.o
>>> diff --git a/drivers/rtc/emul_rtc.c b/drivers/rtc/emul_rtc.c
>>> new file mode 100644
>>> index 0000000000..c98c24bbb3
>>> --- /dev/null
>>> +++ b/drivers/rtc/emul_rtc.c
>>> @@ -0,0 +1,80 @@
>>> +// SPDX-License-Identifier: GPL-2.0+
>>> +/*
>>> + * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
>>> + *
>>> + * This driver emulates a real time clock based on timer ticks.
>>> + */
>>> +
>>> +#include <common.h>
>>> +#include <div64.h>
>>> +#include <dm.h>
>>> +#include <generated/timestamp_autogenerated.h>
>>> +#include <rtc.h>
>>> +
>>> +/**
>>> + * struct emul_rtc - private data for emulated RTC driver
>>> + */
>>> +struct emul_rtc {
>>> + /**
>>> + * @offset_us: microseconds from 1970-01-01 to timer_get_us() base
>>> + */
>>> + u64 offset_us;
>>> + /**
>>> + * @isdst: daylight saving time
>>> + */
>>> + int isdst;
>>> +};
>>> +
>>> +static int emul_rtc_get(struct udevice *dev, struct rtc_time *time)
>>> +{
>>> + struct emul_rtc *priv = dev_get_priv(dev);
>>> + u64 now;
>>> +
>>> + if (!priv->offset_us) {
>>> + /* Use the build date as initial time */
>>> + priv->offset_us = U_BOOT_EPOCH * 1000000ULL - timer_get_us();
>>> + priv->isdst = -1;
>>> + }
>>> +
>>> + now = timer_get_us() + priv->offset_us;
>>> + do_div(now, 1000000);
>>> + rtc_to_tm(now, time);
>>> + time->tm_isdst = priv->isdst;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int emul_rtc_set(struct udevice *dev, const struct rtc_time *time)
>>> +{
>>> + struct emul_rtc *priv = dev_get_priv(dev);
>>> +
>>> + if (time->tm_year < 1970)
>>> + return -EINVAL;
>>> +
>>> + priv->offset_us = rtc_mktime(time) * 1000000ULL - timer_get_us();
>>> +
>>> + if (time->tm_isdst > 0)
>>> + priv->isdst = 1;
>>> + else if (time->tm_isdst < 0)
>>> + priv->isdst = -1;
>>> + else
>>> + priv->isdst = 0;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct rtc_ops emul_rtc_ops = {
>>> + .get = emul_rtc_get,
>>> + .set = emul_rtc_set,
>>> +};
>>> +
>>> +U_BOOT_DRIVER(rtc_emul) = {
>>> + .name = "rtc_emul",
>>> + .id = UCLASS_RTC,
>>> + .ops = &emul_rtc_ops,
>>> + .priv_auto_alloc_size = sizeof(struct emul_rtc),
>>> +};
>>> +
>>> +U_BOOT_DEVICE(rtc_emul) = {
>>> + .name = "rtc_emul",
>>> +};
>>> --
>>> 2.28.0
>>>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 1/2] Makefile: provide constant with seconds since epoch
2020-10-25 7:13 ` [PATCH v2 1/2] Makefile: provide constant with seconds since epoch Heinrich Schuchardt
@ 2020-10-27 4:52 ` Simon Glass
0 siblings, 0 replies; 10+ messages in thread
From: Simon Glass @ 2020-10-27 4:52 UTC (permalink / raw)
To: u-boot
On Sun, 25 Oct 2020 at 01:13, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>
> Provide a constant U_BOOT_EPOCH with the number of seconds since
> 1970-01-01. This constant can be used to initialize a software
> real time clock until it is updated via the 'sntp' command.
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> ---
> v2:
> new patch
> ---
> Makefile | 2 ++
> 1 file changed, 2 insertions(+)
>
Reviewed-by: Simon Glass <sjg@chromium.org>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 2/2] rtc: provide an emulated RTC
2020-10-25 7:13 ` [PATCH v2 2/2] rtc: provide an emulated RTC Heinrich Schuchardt
2020-10-26 15:30 ` Grant Likely
@ 2020-10-27 4:52 ` Simon Glass
1 sibling, 0 replies; 10+ messages in thread
From: Simon Glass @ 2020-10-27 4:52 UTC (permalink / raw)
To: u-boot
Hi Heinrich,
On Sun, 25 Oct 2020 at 01:13, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>
> On a board without hardware clock this software real time clock can be
> used. The build time is used to initialize the RTC. So you will have
> to adjust the time either manually using the 'date' command or use
> the 'sntp' to update the RTC with the time from a network time server.
> See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
> advanced according to CPU ticks.
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
> ---
> v2:
> more elaborate Kconfig message
> adjust device name properties
> use build time as initial time
> ---
> MAINTAINERS | 1 +
> drivers/rtc/Kconfig | 11 ++++++
> drivers/rtc/Makefile | 1 +
> drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 93 insertions(+)
> create mode 100644 drivers/rtc/emul_rtc.c
>
Reviewed-by: Simon Glass <sjg@chromium.org>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index fc4fad46ee..a98e0c5b76 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -678,6 +678,7 @@ S: Maintained
> T: git https://gitlab.denx.de/u-boot/custodians/u-boot-efi.git
> F: doc/api/efi.rst
> F: doc/uefi/*
> +F: drivers/rtc/emul_rtc.c
> F: include/capitalization.h
> F: include/charset.h
> F: include/cp1250.h
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 63662001c2..d06d272e14 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -63,6 +63,17 @@ config RTC_DS3232
> Support for Dallas Semiconductor (now Maxim) DS3232 compatible
> Real Time Clock devices.
>
> +config RTC_EMULATION
> + bool "Enable emulated RTC"
> + depends on DM_RTC
> + help
> + On a board without hardware clock this software real time clock can be
> + used. The build time is used to initialize the RTC. So you will have
> + to adjust the time either manually using the 'date' command or use
> + the 'sntp' to update the RTC with the time from a network time server.
> + See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
> + advanced according to CPU ticks.
> +
> config RTC_ISL1208
> bool "Enable ISL1208 driver"
> depends on DM_RTC
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 12eb449583..ef66dc4bf0 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_RTC_DS164x) += ds164x.o
> obj-$(CONFIG_RTC_DS174x) += ds174x.o
> obj-$(CONFIG_RTC_DS3231) += ds3231.o
> obj-$(CONFIG_RTC_DS3232) += ds3232.o
> +obj-$(CONFIG_RTC_EMULATION) += emul_rtc.o
> obj-$(CONFIG_RTC_FTRTC010) += ftrtc010.o
> obj-$(CONFIG_SANDBOX) += i2c_rtc_emul.o
> obj-$(CONFIG_RTC_IMXDI) += imxdi.o
> diff --git a/drivers/rtc/emul_rtc.c b/drivers/rtc/emul_rtc.c
> new file mode 100644
> index 0000000000..c98c24bbb3
> --- /dev/null
> +++ b/drivers/rtc/emul_rtc.c
> @@ -0,0 +1,80 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2020, Heinrich Schuchardt <xypron.glpk@gmx.de>
> + *
> + * This driver emulates a real time clock based on timer ticks.
> + */
> +
> +#include <common.h>
> +#include <div64.h>
> +#include <dm.h>
> +#include <generated/timestamp_autogenerated.h>
put at end
> +#include <rtc.h>
> +
> +/**
> + * struct emul_rtc - private data for emulated RTC driver
> + */
> +struct emul_rtc {
> + /**
> + * @offset_us: microseconds from 1970-01-01 to timer_get_us() base
> + */
> + u64 offset_us;
> + /**
> + * @isdst: daylight saving time
> + */
why not:
/** @.... */
> + int isdst;
> +};
> +
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 0/2] rtc: provide an emulated RTC
2020-10-25 7:13 [PATCH v2 0/2] rtc: provide an emulated RTC Heinrich Schuchardt
2020-10-25 7:13 ` [PATCH v2 1/2] Makefile: provide constant with seconds since epoch Heinrich Schuchardt
2020-10-25 7:13 ` [PATCH v2 2/2] rtc: provide an emulated RTC Heinrich Schuchardt
@ 2020-10-29 10:27 ` Pablo Sebastián Greco
2020-10-29 11:36 ` Heinrich Schuchardt
2 siblings, 1 reply; 10+ messages in thread
From: Pablo Sebastián Greco @ 2020-10-29 10:27 UTC (permalink / raw)
To: u-boot
Can I suggest as a future enhancement adding an option to also be able
to read U_BOOT_EPOCH from env? Userspace tools could write the time on
shutdown (like fakehwclock).
Ok, adding `date xxxxx` to the start script could work too, but it seems
messy.
Pablo.
On 25/10/20 04:13, Heinrich Schuchardt wrote:
> On a board without hardware clock this software real time clock can be
> used. The build time is used to initialize the RTC. So you will have
> to adjust the time either manually using the 'date' command or use
> the 'sntp' to update the RTC with the time from a network time server.
> See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
> advanced according to CPU ticks.
>
> v2:
> more elaborate Kconfig message
> adjust device name properties
> use build time as initial time
>
> Heinrich Schuchardt (2):
> Makefile: provide constant with seconds since epoch
> rtc: provide an emulated RTC
>
> MAINTAINERS | 1 +
> Makefile | 2 ++
> drivers/rtc/Kconfig | 11 ++++++
> drivers/rtc/Makefile | 1 +
> drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
> 5 files changed, 95 insertions(+)
> create mode 100644 drivers/rtc/emul_rtc.c
>
> --
> 2.28.0
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 0/2] rtc: provide an emulated RTC
2020-10-29 10:27 ` [PATCH v2 0/2] " Pablo Sebastián Greco
@ 2020-10-29 11:36 ` Heinrich Schuchardt
2020-10-30 1:44 ` Pablo Sebastián Greco
0 siblings, 1 reply; 10+ messages in thread
From: Heinrich Schuchardt @ 2020-10-29 11:36 UTC (permalink / raw)
To: u-boot
On 10/29/20 11:27 AM, Pablo Sebasti?n Greco wrote:
> Can I suggest as a future enhancement adding an option to also be able
> to read U_BOOT_EPOCH from env? Userspace tools could write the time on
> shutdown (like fakehwclock).
Thank you for your suggestion.
What does fakehwclock relate to?
> Ok, adding `date xxxxx` to the start script could work too, but it seems
> messy.
If you have network, you should use CONFIG_CMD_SNTP=Y and
CONFIG_BOOTP_NTPSERVER=y and add "setenv autoload no && dhcp && sntp" to
your script.
This is why I submitted the following patch:
net: sntp: remove CONFIG_TIMESTAMP constraint
https://lists.denx.de/pipermail/u-boot/2020-October/430445.html
If we want to follow you idea, we would have a probe() and a remove()
method to the driver for managing the environment variable.
One problem with saving the time on shutdown to the environment is that
save_env() always saves the complete environment and not a single
variable. Saving the complete environment may save changes that you do
not want to persist.
So a complete solution will require:
* Create a function to save a single environment variable selectively.
This will be the part with the biggest effort.
* Implement the probe() and remove() methods
* Add a Kconfig option to enable the usage of the environment variable.
But is this worth the effort if you have SNTP?
Best regards
Heinrich
>
> On 25/10/20 04:13, Heinrich Schuchardt wrote:
>> On a board without hardware clock this software real time clock can be
>> used. The build time is used to initialize the RTC. So you will have
>> to adjust the time either manually using the 'date' command or use
>> the 'sntp' to update the RTC with the time from a network time server.
>> See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
>> advanced according to CPU ticks.
>>
>> v2:
>> more elaborate Kconfig message
>> adjust device name properties
>> use build time as initial time
>>
>> Heinrich Schuchardt (2):
>> Makefile: provide constant with seconds since epoch
>> rtc: provide an emulated RTC
>>
>> MAINTAINERS | 1 +
>> Makefile | 2 ++
>> drivers/rtc/Kconfig | 11 ++++++
>> drivers/rtc/Makefile | 1 +
>> drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
>> 5 files changed, 95 insertions(+)
>> create mode 100644 drivers/rtc/emul_rtc.c
>>
>> --
>> 2.28.0
>>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 0/2] rtc: provide an emulated RTC
2020-10-29 11:36 ` Heinrich Schuchardt
@ 2020-10-30 1:44 ` Pablo Sebastián Greco
0 siblings, 0 replies; 10+ messages in thread
From: Pablo Sebastián Greco @ 2020-10-30 1:44 UTC (permalink / raw)
To: u-boot
On 29/10/20 08:36, Heinrich Schuchardt wrote:
> On 10/29/20 11:27 AM, Pablo Sebasti?n Greco wrote:
>> Can I suggest as a future enhancement adding an option to also be able
>> to read U_BOOT_EPOCH from env? Userspace tools could write the time on
>> shutdown (like fakehwclock).
> Thank you for your suggestion.
>
> What does fakehwclock relate to?
fake-hwclock is a userspace linux tool that saves the current time in a
file, in case ntp is not available at reboot time, so the clock will not
be perfect, but it may be "good enough"
>
>> Ok, adding `date xxxxx` to the start script could work too, but it seems
>> messy.
> If you have network, you should use CONFIG_CMD_SNTP=Y and
> CONFIG_BOOTP_NTPSERVER=y and add "setenv autoload no && dhcp && sntp" to
> your script.
>
> This is why I submitted the following patch:
>
> net: sntp: remove CONFIG_TIMESTAMP constraint
> https://lists.denx.de/pipermail/u-boot/2020-October/430445.html
>
> If we want to follow you idea, we would have a probe() and a remove()
> method to the driver for managing the environment variable.
>
> One problem with saving the time on shutdown to the environment is that
> save_env() always saves the complete environment and not a single
> variable. Saving the complete environment may save changes that you do
> not want to persist.
>
> So a complete solution will require:
>
> * Create a function to save a single environment variable selectively.
> This will be the part with the biggest effort.
That would be nice to have, even if not related to this.
> * Implement the probe() and remove() methods
> * Add a Kconfig option to enable the usage of the environment variable.
>
> But is this worth the effort if you have SNTP?
If SNTP is available, I agree that it makes no sense. but may not always
be the case (as noted before), and some programs don't react too kindly
to the clock jumping ahead several years during boot, so it would be
nice to have a "good enough" clock before the kernel takes over,
Also, as was mentioned in other parts of the thread, some devices may be
too close to the size limit, but I'd happily exchange network in uboot
for this driver.
I know the idea is a bit wacky, but thought it could be useful ;)
>
> Best regards
>
> Heinrich
>
>> On 25/10/20 04:13, Heinrich Schuchardt wrote:
>>> On a board without hardware clock this software real time clock can be
>>> used. The build time is used to initialize the RTC. So you will have
>>> to adjust the time either manually using the 'date' command or use
>>> the 'sntp' to update the RTC with the time from a network time server.
>>> See CONFIG_CMD_SNTP and CONFIG_BOOTP_NTPSERVER. The RTC time is
>>> advanced according to CPU ticks.
>>>
>>> v2:
>>> more elaborate Kconfig message
>>> adjust device name properties
>>> use build time as initial time
>>>
>>> Heinrich Schuchardt (2):
>>> Makefile: provide constant with seconds since epoch
>>> rtc: provide an emulated RTC
>>>
>>> MAINTAINERS | 1 +
>>> Makefile | 2 ++
>>> drivers/rtc/Kconfig | 11 ++++++
>>> drivers/rtc/Makefile | 1 +
>>> drivers/rtc/emul_rtc.c | 80 ++++++++++++++++++++++++++++++++++++++++++
>>> 5 files changed, 95 insertions(+)
>>> create mode 100644 drivers/rtc/emul_rtc.c
>>>
>>> --
>>> 2.28.0
>>>
Pablo
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2020-10-30 1:44 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-25 7:13 [PATCH v2 0/2] rtc: provide an emulated RTC Heinrich Schuchardt
2020-10-25 7:13 ` [PATCH v2 1/2] Makefile: provide constant with seconds since epoch Heinrich Schuchardt
2020-10-27 4:52 ` Simon Glass
2020-10-25 7:13 ` [PATCH v2 2/2] rtc: provide an emulated RTC Heinrich Schuchardt
2020-10-26 15:30 ` Grant Likely
[not found] ` <CACxGe6uz2_cysTuPC6zZRiTLkPCHbz6+9edqMzktQB3orY1R5w@mail.gmail.com>
2020-10-26 19:18 ` Heinrich Schuchardt
2020-10-27 4:52 ` Simon Glass
2020-10-29 10:27 ` [PATCH v2 0/2] " Pablo Sebastián Greco
2020-10-29 11:36 ` Heinrich Schuchardt
2020-10-30 1:44 ` Pablo Sebastián Greco
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