| /* |
| * 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) |
| { |
| s64 rc = OPAL_BUSY; |
| int retries = 10; |
| 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) { |
| msleep(OPAL_BUSY_DELAY_MS); |
| opal_poll_events(NULL); |
| } else if (rc == OPAL_BUSY) { |
| msleep(OPAL_BUSY_DELAY_MS); |
| } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { |
| if (retries--) { |
| msleep(10); /* Wait 10ms before retry */ |
| rc = OPAL_BUSY; /* go around again */ |
| } |
| } |
| } |
| |
| 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) |
| { |
| s64 rc = OPAL_BUSY; |
| int retries = 10; |
| 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) { |
| msleep(OPAL_BUSY_DELAY_MS); |
| opal_poll_events(NULL); |
| } else if (rc == OPAL_BUSY) { |
| msleep(OPAL_BUSY_DELAY_MS); |
| } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { |
| if (retries--) { |
| msleep(10); /* Wait 10ms before retry */ |
| rc = OPAL_BUSY; /* go around again */ |
| } |
| } |
| } |
| |
| 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; |
| |
| tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms); |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| 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); |