| Message ID | 20190123183325.92946-5-ncrews@chromium.org |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | platform/chrome: rtc: Add support for Wilco EC | expand |
On 23/01/2019 11:33:20-0700, Nick Crews wrote: > From: Duncan Laurie <dlaurie@google.com> > > This Embedded Controller has an internal RTC that is exposed > as a standard RTC class driver with read/write functionality. > > The driver is added to the drivers/rtc/ so that the maintainer of that > directory will be able to comment on this change, as that maintainer is > the expert on this system. In addition, the driver code is called > indirectly after a corresponding device is registered from core.c, > as opposed to core.c registering the driver callbacks directly. > > > hwclock --show --rtc /dev/rtc1 > 2007-12-31 16:01:20.460959-08:00 > > hwclock --systohc --rtc /dev/rtc1 > > hwclock --show --rtc /dev/rtc1 > 2018-11-29 17:08:00.780793-08:00 > > Signed-off-by: Duncan Laurie <dlaurie@google.com> > Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> > Signed-off-by: Nick Crews <ncrews@chromium.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > > Changes in v4: > - Change me email to @chromium.org from @google.com > - Move "Add RTC driver" before "Add sysfs attributes" so that > it could get accepted earlier, since it is less contentious > > Changes in v3: > - rm #define for driver name > - Don't compute weekday when reading from RTC. > Still set weekday when writing, as RTC needs this > to control advanced power scheduling > - rm check for invalid month data > - Set range_min and range_max on rtc_device > > Changes in v2: > - rm license boiler plate > - rm "wilco_ec_rtc -" prefix in docstring > - Make rtc driver its own module within the drivers/rtc/ directory > - Register a rtc device from core.c that is picked up by this driver > > drivers/platform/chrome/wilco_ec/core.c | 14 ++ > drivers/rtc/Kconfig | 11 ++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-wilco-ec.c | 177 ++++++++++++++++++++++++ > 4 files changed, 203 insertions(+) > create mode 100644 drivers/rtc/rtc-wilco-ec.c > > diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c > index e036d88b6dd8..7cfb047e2c89 100644 > --- a/drivers/platform/chrome/wilco_ec/core.c > +++ b/drivers/platform/chrome/wilco_ec/core.c > @@ -87,6 +87,20 @@ static int wilco_ec_probe(struct platform_device *pdev) > goto destroy_mec; > } > > + /* > + * Register a RTC platform device that will get picked up by the RTC > + * subsystem. This platform device will get freed when its parent device > + * dev is unregistered. > + */ > + child_pdev = platform_device_register_data(dev, "rtc-wilco-ec", > + PLATFORM_DEVID_AUTO, > + NULL, 0); > + if (IS_ERR(child_pdev)) { > + dev_err(dev, "Failed to create RTC platform device\n"); > + ret = PTR_ERR(child_pdev); > + goto destroy_mec; > + } > + > return 0; > > destroy_mec: > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 225b0b8516f3..d5063c791515 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -1814,4 +1814,15 @@ config RTC_DRV_GOLDFISH > Goldfish is a code name for the virtual platform developed by Google > for Android emulation. > > +config RTC_DRV_WILCO_EC > + tristate "Wilco EC RTC" > + depends on WILCO_EC > + default m > + help > + If you say yes here, you get read/write support for the Real Time > + Clock on the Wilco Embedded Controller (Wilco is a kind of Chromebook) > + > + This can also be built as a module. If so, the module will > + be named "rtc_wilco_ec". > + > endif # RTC_CLASS > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index df022d820bee..6255ea78da25 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -172,6 +172,7 @@ obj-$(CONFIG_RTC_DRV_V3020) += rtc-v3020.o > obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o > obj-$(CONFIG_RTC_DRV_VRTC) += rtc-mrst.o > obj-$(CONFIG_RTC_DRV_VT8500) += rtc-vt8500.o > +obj-$(CONFIG_RTC_DRV_WILCO_EC) += rtc-wilco-ec.o > obj-$(CONFIG_RTC_DRV_WM831X) += rtc-wm831x.o > obj-$(CONFIG_RTC_DRV_WM8350) += rtc-wm8350.o > obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o > diff --git a/drivers/rtc/rtc-wilco-ec.c b/drivers/rtc/rtc-wilco-ec.c > new file mode 100644 > index 000000000000..35cc56114c1c > --- /dev/null > +++ b/drivers/rtc/rtc-wilco-ec.c > @@ -0,0 +1,177 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * RTC interface for Wilco Embedded Controller with R/W abilities > + * > + * Copyright 2018 Google LLC > + * > + * The corresponding platform device is typically registered in > + * drivers/platform/chrome/wilco_ec/core.c > + */ > + > +#include <linux/bcd.h> > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/platform_data/wilco-ec.h> > +#include <linux/rtc.h> > +#include <linux/timekeeping.h> > + > +#define EC_COMMAND_CMOS 0x7c > +#define EC_CMOS_TOD_WRITE 0x02 > +#define EC_CMOS_TOD_READ 0x08 > + > +/** > + * struct ec_rtc_read - Format of RTC returned by EC. > + * @second: Second value (0..59) > + * @minute: Minute value (0..59) > + * @hour: Hour value (0..23) > + * @day: Day value (1..31) > + * @month: Month value (1..12) > + * @year: Year value (full year % 100) > + * @century: Century value (full year / 100) > + * > + * All values are presented in binary (not BCD). > + */ > +struct ec_rtc_read { > + u8 second; > + u8 minute; > + u8 hour; > + u8 day; > + u8 month; > + u8 year; > + u8 century; > +} __packed; > + > +/** > + * struct ec_rtc_write - Format of RTC sent to the EC. > + * @param: EC_CMOS_TOD_WRITE > + * @century: Century value (full year / 100) > + * @year: Year value (full year % 100) > + * @month: Month value (1..12) > + * @day: Day value (1..31) > + * @hour: Hour value (0..23) > + * @minute: Minute value (0..59) > + * @second: Second value (0..59) > + * @weekday: Day of the week (0=Saturday) > + * > + * All values are presented in BCD. > + */ > +struct ec_rtc_write { > + u8 param; > + u8 century; > + u8 year; > + u8 month; > + u8 day; > + u8 hour; > + u8 minute; > + u8 second; > + u8 weekday; > +} __packed; > + > +int wilco_ec_rtc_read(struct device *dev, struct rtc_time *tm) > +{ > + struct wilco_ec_device *ec = dev_get_drvdata(dev->parent); > + u8 param = EC_CMOS_TOD_READ; > + struct ec_rtc_read rtc; > + struct wilco_ec_message msg = { > + .type = WILCO_EC_MSG_LEGACY, > + .flags = WILCO_EC_FLAG_RAW_RESPONSE, > + .command = EC_COMMAND_CMOS, > + .request_data = ¶m, > + .request_size = sizeof(param), > + .response_data = &rtc, > + .response_size = sizeof(rtc), > + }; > + int ret; > + > + ret = wilco_ec_mailbox(ec, &msg); > + if (ret < 0) > + return ret; > + > + tm->tm_sec = rtc.second; > + tm->tm_min = rtc.minute; > + tm->tm_hour = rtc.hour; > + tm->tm_mday = rtc.day; > + tm->tm_mon = rtc.month - 1; > + tm->tm_year = rtc.year + (rtc.century * 100) - 1900; > + tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); > + > + /* Don't compute day of week, we don't need it. */ > + tm->tm_wday = -1; > + > + return 0; > +} > + > +int wilco_ec_rtc_write(struct device *dev, struct rtc_time *tm) > +{ > + struct wilco_ec_device *ec = dev_get_drvdata(dev->parent); > + struct ec_rtc_write rtc; > + struct wilco_ec_message msg = { > + .type = WILCO_EC_MSG_LEGACY, > + .flags = WILCO_EC_FLAG_RAW_RESPONSE, > + .command = EC_COMMAND_CMOS, > + .request_data = &rtc, > + .request_size = sizeof(rtc), > + }; > + int year = tm->tm_year + 1900; > + /* > + * Convert from 0=Sunday to 0=Saturday for the EC > + * We DO need to set weekday because the EC controls battery charging > + * schedules that depend on the day of the week. > + */ > + int wday = tm->tm_wday == 6 ? 0 : tm->tm_wday + 1; > + int ret; > + > + rtc.param = EC_CMOS_TOD_WRITE; > + rtc.century = bin2bcd(year / 100); > + rtc.year = bin2bcd(year % 100); > + rtc.month = bin2bcd(tm->tm_mon + 1); > + rtc.day = bin2bcd(tm->tm_mday); > + rtc.hour = bin2bcd(tm->tm_hour); > + rtc.minute = bin2bcd(tm->tm_min); > + rtc.second = bin2bcd(tm->tm_sec); > + rtc.weekday = bin2bcd(wday); > + > + ret = wilco_ec_mailbox(ec, &msg); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static const struct rtc_class_ops wilco_ec_rtc_ops = { > + .read_time = wilco_ec_rtc_read, > + .set_time = wilco_ec_rtc_write, > +}; > + > +static int wilco_ec_rtc_probe(struct platform_device *pdev) > +{ > + struct rtc_device *rtc; > + > + rtc = devm_rtc_allocate_device(&pdev->dev); > + if (IS_ERR(rtc)) > + return PTR_ERR(rtc); > + > + rtc->ops = &wilco_ec_rtc_ops; > + /* EC only supports this century */ > + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; > + rtc->range_max = RTC_TIMESTAMP_END_2099; > + rtc->owner = THIS_MODULE; > + > + return rtc_register_device(rtc); > +} > + > +static struct platform_driver wilco_ec_rtc_driver = { > + .driver = { > + .name = "rtc-wilco-ec", > + }, > + .probe = wilco_ec_rtc_probe, > +}; > + > +module_platform_driver(wilco_ec_rtc_driver); > + > +MODULE_ALIAS("platform:rtc-wilco-ec"); > +MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>"); > +MODULE_LICENSE("GPL v2"); > +MODULE_DESCRIPTION("Wilco EC RTC driver"); > -- > 2.20.1.321.g9e740568ce-goog >
diff --git a/drivers/platform/chrome/wilco_ec/core.c b/drivers/platform/chrome/wilco_ec/core.c index e036d88b6dd8..7cfb047e2c89 100644 --- a/drivers/platform/chrome/wilco_ec/core.c +++ b/drivers/platform/chrome/wilco_ec/core.c @@ -87,6 +87,20 @@ static int wilco_ec_probe(struct platform_device *pdev) goto destroy_mec; } + /* + * Register a RTC platform device that will get picked up by the RTC + * subsystem. This platform device will get freed when its parent device + * dev is unregistered. + */ + child_pdev = platform_device_register_data(dev, "rtc-wilco-ec", + PLATFORM_DEVID_AUTO, + NULL, 0); + if (IS_ERR(child_pdev)) { + dev_err(dev, "Failed to create RTC platform device\n"); + ret = PTR_ERR(child_pdev); + goto destroy_mec; + } + return 0; destroy_mec: diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 225b0b8516f3..d5063c791515 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1814,4 +1814,15 @@ config RTC_DRV_GOLDFISH Goldfish is a code name for the virtual platform developed by Google for Android emulation. +config RTC_DRV_WILCO_EC + tristate "Wilco EC RTC" + depends on WILCO_EC + default m + help + If you say yes here, you get read/write support for the Real Time + Clock on the Wilco Embedded Controller (Wilco is a kind of Chromebook) + + This can also be built as a module. If so, the module will + be named "rtc_wilco_ec". + endif # RTC_CLASS diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index df022d820bee..6255ea78da25 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -172,6 +172,7 @@ obj-$(CONFIG_RTC_DRV_V3020) += rtc-v3020.o obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o obj-$(CONFIG_RTC_DRV_VRTC) += rtc-mrst.o obj-$(CONFIG_RTC_DRV_VT8500) += rtc-vt8500.o +obj-$(CONFIG_RTC_DRV_WILCO_EC) += rtc-wilco-ec.o obj-$(CONFIG_RTC_DRV_WM831X) += rtc-wm831x.o obj-$(CONFIG_RTC_DRV_WM8350) += rtc-wm8350.o obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o diff --git a/drivers/rtc/rtc-wilco-ec.c b/drivers/rtc/rtc-wilco-ec.c new file mode 100644 index 000000000000..35cc56114c1c --- /dev/null +++ b/drivers/rtc/rtc-wilco-ec.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RTC interface for Wilco Embedded Controller with R/W abilities + * + * Copyright 2018 Google LLC + * + * The corresponding platform device is typically registered in + * drivers/platform/chrome/wilco_ec/core.c + */ + +#include <linux/bcd.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/platform_data/wilco-ec.h> +#include <linux/rtc.h> +#include <linux/timekeeping.h> + +#define EC_COMMAND_CMOS 0x7c +#define EC_CMOS_TOD_WRITE 0x02 +#define EC_CMOS_TOD_READ 0x08 + +/** + * struct ec_rtc_read - Format of RTC returned by EC. + * @second: Second value (0..59) + * @minute: Minute value (0..59) + * @hour: Hour value (0..23) + * @day: Day value (1..31) + * @month: Month value (1..12) + * @year: Year value (full year % 100) + * @century: Century value (full year / 100) + * + * All values are presented in binary (not BCD). + */ +struct ec_rtc_read { + u8 second; + u8 minute; + u8 hour; + u8 day; + u8 month; + u8 year; + u8 century; +} __packed; + +/** + * struct ec_rtc_write - Format of RTC sent to the EC. + * @param: EC_CMOS_TOD_WRITE + * @century: Century value (full year / 100) + * @year: Year value (full year % 100) + * @month: Month value (1..12) + * @day: Day value (1..31) + * @hour: Hour value (0..23) + * @minute: Minute value (0..59) + * @second: Second value (0..59) + * @weekday: Day of the week (0=Saturday) + * + * All values are presented in BCD. + */ +struct ec_rtc_write { + u8 param; + u8 century; + u8 year; + u8 month; + u8 day; + u8 hour; + u8 minute; + u8 second; + u8 weekday; +} __packed; + +int wilco_ec_rtc_read(struct device *dev, struct rtc_time *tm) +{ + struct wilco_ec_device *ec = dev_get_drvdata(dev->parent); + u8 param = EC_CMOS_TOD_READ; + struct ec_rtc_read rtc; + struct wilco_ec_message msg = { + .type = WILCO_EC_MSG_LEGACY, + .flags = WILCO_EC_FLAG_RAW_RESPONSE, + .command = EC_COMMAND_CMOS, + .request_data = ¶m, + .request_size = sizeof(param), + .response_data = &rtc, + .response_size = sizeof(rtc), + }; + int ret; + + ret = wilco_ec_mailbox(ec, &msg); + if (ret < 0) + return ret; + + tm->tm_sec = rtc.second; + tm->tm_min = rtc.minute; + tm->tm_hour = rtc.hour; + tm->tm_mday = rtc.day; + tm->tm_mon = rtc.month - 1; + tm->tm_year = rtc.year + (rtc.century * 100) - 1900; + tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); + + /* Don't compute day of week, we don't need it. */ + tm->tm_wday = -1; + + return 0; +} + +int wilco_ec_rtc_write(struct device *dev, struct rtc_time *tm) +{ + struct wilco_ec_device *ec = dev_get_drvdata(dev->parent); + struct ec_rtc_write rtc; + struct wilco_ec_message msg = { + .type = WILCO_EC_MSG_LEGACY, + .flags = WILCO_EC_FLAG_RAW_RESPONSE, + .command = EC_COMMAND_CMOS, + .request_data = &rtc, + .request_size = sizeof(rtc), + }; + int year = tm->tm_year + 1900; + /* + * Convert from 0=Sunday to 0=Saturday for the EC + * We DO need to set weekday because the EC controls battery charging + * schedules that depend on the day of the week. + */ + int wday = tm->tm_wday == 6 ? 0 : tm->tm_wday + 1; + int ret; + + rtc.param = EC_CMOS_TOD_WRITE; + rtc.century = bin2bcd(year / 100); + rtc.year = bin2bcd(year % 100); + rtc.month = bin2bcd(tm->tm_mon + 1); + rtc.day = bin2bcd(tm->tm_mday); + rtc.hour = bin2bcd(tm->tm_hour); + rtc.minute = bin2bcd(tm->tm_min); + rtc.second = bin2bcd(tm->tm_sec); + rtc.weekday = bin2bcd(wday); + + ret = wilco_ec_mailbox(ec, &msg); + if (ret < 0) + return ret; + + return 0; +} + +static const struct rtc_class_ops wilco_ec_rtc_ops = { + .read_time = wilco_ec_rtc_read, + .set_time = wilco_ec_rtc_write, +}; + +static int wilco_ec_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &wilco_ec_rtc_ops; + /* EC only supports this century */ + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + rtc->owner = THIS_MODULE; + + return rtc_register_device(rtc); +} + +static struct platform_driver wilco_ec_rtc_driver = { + .driver = { + .name = "rtc-wilco-ec", + }, + .probe = wilco_ec_rtc_probe, +}; + +module_platform_driver(wilco_ec_rtc_driver); + +MODULE_ALIAS("platform:rtc-wilco-ec"); +MODULE_AUTHOR("Nick Crews <ncrews@chromium.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Wilco EC RTC driver");