diff options
Diffstat (limited to 'kernel/drivers/rtc/rtc-opal.c')
| -rw-r--r-- | kernel/drivers/rtc/rtc-opal.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/kernel/drivers/rtc/rtc-opal.c b/kernel/drivers/rtc/rtc-opal.c new file mode 100644 index 000000000..7061dcae2 --- /dev/null +++ b/kernel/drivers/rtc/rtc-opal.c @@ -0,0 +1,262 @@ +/* + * 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); + + GregorianDay(tm); +} + +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 = be64_to_cpu(msg.params[1]); + 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); + 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, token; + struct opal_msg msg; + u32 y_m_d = 0; + int 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 = be64_to_cpu(msg.params[1]); + if (rc != OPAL_SUCCESS) + rc = -EIO; + +exit: + opal_async_release_token(token); + return rc; +} + +static const struct rtc_class_ops opal_rtc_ops = { + .read_time = opal_get_rtc_time, + .set_time = opal_set_rtc_time, + .read_alarm = opal_get_tpo_time, + .set_alarm = opal_set_tpo_time, +}; + +static int opal_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtc; + + if (pdev->dev.of_node && of_get_property(pdev->dev.of_node, "has-tpo", + NULL)) + device_set_wakeup_capable(&pdev->dev, true); + + 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, + .owner = THIS_MODULE, + .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); |