platform/chrome: wilco_ec: Add RTC driver (0d2f2a3d) · Commits · 戴 / test

drivers/platform/chrome/wilco_ec/core.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,7 @@ static int wilco_ec_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct wilco_ec_device *ec;
		int ret;

		ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL);
		if (!ec)
		@@ -78,13 +79,30 @@ static int wilco_ec_probe(struct platform_device *pdev)
		PLATFORM_DEVID_AUTO,
		NULL, 0);

		/* Register a child device that will be found by the RTC driver. */
		ec->rtc_pdev = platform_device_register_data(dev, "rtc-wilco-ec",
		PLATFORM_DEVID_AUTO,
		NULL, 0);
		if (IS_ERR(ec->rtc_pdev)) {
		dev_err(dev, "Failed to create RTC platform device\n");
		ret = PTR_ERR(ec->rtc_pdev);
		goto unregister_debugfs;
		}

		return 0;

		unregister_debugfs:
		if (ec->debugfs_pdev)
		platform_device_unregister(ec->debugfs_pdev);
		cros_ec_lpc_mec_destroy();
		return ret;
		}

		static int wilco_ec_remove(struct platform_device *pdev)
		{
		struct wilco_ec_device *ec = platform_get_drvdata(pdev);

		platform_device_unregister(ec->rtc_pdev);
		if (ec->debugfs_pdev)
		platform_device_unregister(ec->debugfs_pdev);

drivers/rtc/Kconfig

+11 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/rtc/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/rtc/rtc-wilco-ec.c

0 → 100644

+177 −0

Original line number	Diff line number	Diff line
		// 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;

		static 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 = &param,
		.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;
		}

		static 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");

include/linux/platform_data/wilco-ec.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -35,6 +35,7 @@
		* is used to hold the request and the response.
		* @data_size: Size of the data buffer used for EC communication.
		* @debugfs_pdev: The child platform_device used by the debugfs sub-driver.
		* @rtc_pdev: The child platform_device used by the RTC sub-driver.
		*/
		struct wilco_ec_device {
		struct device *dev;
		@@ -45,6 +46,7 @@ struct wilco_ec_device {
		void *data_buffer;
		size_t data_size;
		struct platform_device *debugfs_pdev;
		struct platform_device *rtc_pdev;
		};

		/**

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