/* * IBM OPAL RTC driver * Copyright (C) 2014 IBM * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #define DRVNAME		"rtc-opal" #include <linux/module.h>#include <linux/err.h>#include <linux/rtc.h>#include <linux/delay.h>#include <linux/bcd.h>#include <linux/platform_device.h>#include <linux/of.h>#include <asm/opal.h>#include <asm/firmware.h> static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm){	tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +		       bcd2bin((y_m_d >> 16) & 0xff)) - 1900;	tm->tm_mon  = bcd2bin((y_m_d >> 8) & 0xff) - 1;	tm->tm_mday = bcd2bin(y_m_d & 0xff);	tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);	tm->tm_min  = bcd2bin((h_m_s_ms >> 48) & 0xff);	tm->tm_sec  = bcd2bin((h_m_s_ms >> 40) & 0xff); 	tm->tm_wday = -1;} static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms){	*y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;	*y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;	*y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;	*y_m_d |= ((u32)bin2bcd(tm->tm_mday)); 	*h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;	*h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;	*h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;} static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm){	long rc = OPAL_BUSY;	u32 y_m_d;	u64 h_m_s_ms;	__be32 __y_m_d;	__be64 __h_m_s_ms; 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {		rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);		if (rc == OPAL_BUSY_EVENT)			opal_poll_events(NULL);		else			msleep(10);	} 	if (rc != OPAL_SUCCESS)		return -EIO; 	y_m_d = be32_to_cpu(__y_m_d);	h_m_s_ms = be64_to_cpu(__h_m_s_ms);	opal_to_tm(y_m_d, h_m_s_ms, tm); 	return 0;} static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm){	long rc = OPAL_BUSY;	u32 y_m_d = 0;	u64 h_m_s_ms = 0; 	tm_to_opal(tm, &y_m_d, &h_m_s_ms);	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {		rc = opal_rtc_write(y_m_d, h_m_s_ms);		if (rc == OPAL_BUSY_EVENT)			opal_poll_events(NULL);		else			msleep(10);	} 	return rc == OPAL_SUCCESS ? 0 : -EIO;} /* * TPO	Timed Power-On * * TPO get/set OPAL calls care about the hour and min and to make it consistent * with the rtc utility time conversion functions, we use the 'u64' to store * its value and perform bit shift by 32 before use.. */static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm){	__be32 __y_m_d, __h_m;	struct opal_msg msg;	int rc, token;	u64 h_m_s_ms;	u32 y_m_d; 	token = opal_async_get_token_interruptible();	if (token < 0) {		if (token != -ERESTARTSYS)			pr_err("Failed to get the async token\n"); 		return token;	} 	rc = opal_tpo_read(token, &__y_m_d, &__h_m);	if (rc != OPAL_ASYNC_COMPLETION) {		rc = -EIO;		goto exit;	} 	rc = opal_async_wait_response(token, &msg);	if (rc) {		rc = -EIO;		goto exit;	} 	rc = opal_get_async_rc(msg);	if (rc != OPAL_SUCCESS) {		rc = -EIO;		goto exit;	} 	y_m_d = be32_to_cpu(__y_m_d);	h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); 	/* check if no alarm is set */	if (y_m_d == 0 && h_m_s_ms == 0) {		pr_debug("No alarm is set\n");		rc = -ENOENT;		goto exit;	} else {		pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms);	} 	opal_to_tm(y_m_d, h_m_s_ms, &alarm->time); exit:	opal_async_release_token(token);	return rc;} /* Set Timed Power-On */static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm){	u64 h_m_s_ms = 0;	struct opal_msg msg;	u32 y_m_d = 0;	int token, rc; 	/* if alarm is enabled */	if (alarm->enabled) {		tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);		pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); 	} else {		pr_debug("Alarm getting disabled\n");	} 	token = opal_async_get_token_interruptible();	if (token < 0) {		if (token != -ERESTARTSYS)			pr_err("Failed to get the async token\n"); 		return token;	} 	/* TPO, we care about hour and minute */	rc = opal_tpo_write(token, y_m_d,			    (u32)((h_m_s_ms >> 32) & 0xffff0000));	if (rc != OPAL_ASYNC_COMPLETION) {		rc = -EIO;		goto exit;	} 	rc = opal_async_wait_response(token, &msg);	if (rc) {		rc = -EIO;		goto exit;	} 	rc = opal_get_async_rc(msg);	if (rc != OPAL_SUCCESS)		rc = -EIO; exit:	opal_async_release_token(token);	return rc;} int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled){	struct rtc_wkalrm alarm = { .enabled = 0 }; 	/*	 * TPO is automatically enabled when opal_set_tpo_time() is called with	 * non-zero rtc-time. We only handle disable case which needs to be	 * explicitly told to opal.	 */	return enabled ? 0 : opal_set_tpo_time(dev, &alarm);} static struct rtc_class_ops opal_rtc_ops = {	.read_time	= opal_get_rtc_time,	.set_time	= opal_set_rtc_time,}; static int opal_rtc_probe(struct platform_device *pdev){	struct rtc_device *rtc; 	if (pdev->dev.of_node &&	    (of_property_read_bool(pdev->dev.of_node, "wakeup-source") ||	     of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */)) {		device_set_wakeup_capable(&pdev->dev, true);		opal_rtc_ops.read_alarm	= opal_get_tpo_time;		opal_rtc_ops.set_alarm = opal_set_tpo_time;		opal_rtc_ops.alarm_irq_enable = opal_tpo_alarm_irq_enable;	} 	rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops,				       THIS_MODULE);	if (IS_ERR(rtc))		return PTR_ERR(rtc); 	rtc->uie_unsupported = 1; 	return 0;} static const struct of_device_id opal_rtc_match[] = {	{		.compatible	= "ibm,opal-rtc",	},	{ }};MODULE_DEVICE_TABLE(of, opal_rtc_match); static const struct platform_device_id opal_rtc_driver_ids[] = {	{		.name		= "opal-rtc",	},	{ }};MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids); static struct platform_driver opal_rtc_driver = {	.probe		= opal_rtc_probe,	.id_table	= opal_rtc_driver_ids,	.driver		= {		.name		= DRVNAME,		.of_match_table	= opal_rtc_match,	},}; static int __init opal_rtc_init(void){	if (!firmware_has_feature(FW_FEATURE_OPAL))		return -ENODEV; 	return platform_driver_register(&opal_rtc_driver);} static void __exit opal_rtc_exit(void){	platform_driver_unregister(&opal_rtc_driver);} MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");MODULE_DESCRIPTION("IBM OPAL RTC driver");MODULE_LICENSE("GPL"); module_init(opal_rtc_init);module_exit(opal_rtc_exit);