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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * IBM OPAL RTC driver4 * Copyright (C) 2014 IBM5 */6 7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt8 9#define DRVNAME "rtc-opal"10 11#include <linux/module.h>12#include <linux/err.h>13#include <linux/rtc.h>14#include <linux/delay.h>15#include <linux/bcd.h>16#include <linux/platform_device.h>17#include <linux/of.h>18#include <asm/opal.h>19#include <asm/firmware.h>20 21static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)22{23 tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +24 bcd2bin((y_m_d >> 16) & 0xff)) - 1900;25 tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1;26 tm->tm_mday = bcd2bin(y_m_d & 0xff);27 tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);28 tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff);29 tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff);30 31 tm->tm_wday = -1;32}33 34static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms)35{36 *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;37 *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;38 *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;39 *y_m_d |= ((u32)bin2bcd(tm->tm_mday));40 41 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;42 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;43 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;44}45 46static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm)47{48 s64 rc = OPAL_BUSY;49 int retries = 10;50 u32 y_m_d;51 u64 h_m_s_ms;52 __be32 __y_m_d;53 __be64 __h_m_s_ms;54 55 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {56 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);57 if (rc == OPAL_BUSY_EVENT) {58 msleep(OPAL_BUSY_DELAY_MS);59 opal_poll_events(NULL);60 } else if (rc == OPAL_BUSY) {61 msleep(OPAL_BUSY_DELAY_MS);62 } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) {63 if (retries--) {64 msleep(10); /* Wait 10ms before retry */65 rc = OPAL_BUSY; /* go around again */66 }67 }68 }69 70 if (rc != OPAL_SUCCESS)71 return -EIO;72 73 y_m_d = be32_to_cpu(__y_m_d);74 h_m_s_ms = be64_to_cpu(__h_m_s_ms);75 opal_to_tm(y_m_d, h_m_s_ms, tm);76 77 return 0;78}79 80static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm)81{82 s64 rc = OPAL_BUSY;83 int retries = 10;84 u32 y_m_d = 0;85 u64 h_m_s_ms = 0;86 87 tm_to_opal(tm, &y_m_d, &h_m_s_ms);88 89 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {90 rc = opal_rtc_write(y_m_d, h_m_s_ms);91 if (rc == OPAL_BUSY_EVENT) {92 msleep(OPAL_BUSY_DELAY_MS);93 opal_poll_events(NULL);94 } else if (rc == OPAL_BUSY) {95 msleep(OPAL_BUSY_DELAY_MS);96 } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) {97 if (retries--) {98 msleep(10); /* Wait 10ms before retry */99 rc = OPAL_BUSY; /* go around again */100 }101 }102 }103 104 return rc == OPAL_SUCCESS ? 0 : -EIO;105}106 107/*108 * TPO Timed Power-On109 *110 * TPO get/set OPAL calls care about the hour and min and to make it consistent111 * with the rtc utility time conversion functions, we use the 'u64' to store112 * its value and perform bit shift by 32 before use..113 */114static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)115{116 __be32 __y_m_d, __h_m;117 struct opal_msg msg;118 int rc, token;119 u64 h_m_s_ms;120 u32 y_m_d;121 122 token = opal_async_get_token_interruptible();123 if (token < 0) {124 if (token != -ERESTARTSYS)125 pr_err("Failed to get the async token\n");126 127 return token;128 }129 130 rc = opal_tpo_read(token, &__y_m_d, &__h_m);131 if (rc != OPAL_ASYNC_COMPLETION) {132 rc = -EIO;133 goto exit;134 }135 136 rc = opal_async_wait_response(token, &msg);137 if (rc) {138 rc = -EIO;139 goto exit;140 }141 142 rc = opal_get_async_rc(msg);143 if (rc != OPAL_SUCCESS) {144 rc = -EIO;145 goto exit;146 }147 148 y_m_d = be32_to_cpu(__y_m_d);149 h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32);150 151 /* check if no alarm is set */152 if (y_m_d == 0 && h_m_s_ms == 0) {153 pr_debug("No alarm is set\n");154 rc = -ENOENT;155 goto exit;156 } else {157 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms);158 }159 160 opal_to_tm(y_m_d, h_m_s_ms, &alarm->time);161 162exit:163 opal_async_release_token(token);164 return rc;165}166 167/* Set Timed Power-On */168static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)169{170 u64 h_m_s_ms = 0;171 struct opal_msg msg;172 u32 y_m_d = 0;173 int token, rc;174 175 /* if alarm is enabled */176 if (alarm->enabled) {177 tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);178 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms);179 180 } else {181 pr_debug("Alarm getting disabled\n");182 }183 184 token = opal_async_get_token_interruptible();185 if (token < 0) {186 if (token != -ERESTARTSYS)187 pr_err("Failed to get the async token\n");188 189 return token;190 }191 192 /* TPO, we care about hour and minute */193 rc = opal_tpo_write(token, y_m_d,194 (u32)((h_m_s_ms >> 32) & 0xffff0000));195 if (rc != OPAL_ASYNC_COMPLETION) {196 rc = -EIO;197 goto exit;198 }199 200 rc = opal_async_wait_response(token, &msg);201 if (rc) {202 rc = -EIO;203 goto exit;204 }205 206 rc = opal_get_async_rc(msg);207 if (rc != OPAL_SUCCESS)208 rc = -EIO;209 210exit:211 opal_async_release_token(token);212 return rc;213}214 215static int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled)216{217 struct rtc_wkalrm alarm = { .enabled = 0 };218 219 /*220 * TPO is automatically enabled when opal_set_tpo_time() is called with221 * non-zero rtc-time. We only handle disable case which needs to be222 * explicitly told to opal.223 */224 return enabled ? 0 : opal_set_tpo_time(dev, &alarm);225}226 227static const struct rtc_class_ops opal_rtc_ops = {228 .read_time = opal_get_rtc_time,229 .set_time = opal_set_rtc_time,230 .read_alarm = opal_get_tpo_time,231 .set_alarm = opal_set_tpo_time,232 .alarm_irq_enable = opal_tpo_alarm_irq_enable,233};234 235static int opal_rtc_probe(struct platform_device *pdev)236{237 struct rtc_device *rtc;238 239 rtc = devm_rtc_allocate_device(&pdev->dev);240 if (IS_ERR(rtc))241 return PTR_ERR(rtc);242 243 if (pdev->dev.of_node &&244 (of_property_read_bool(pdev->dev.of_node, "wakeup-source") ||245 of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */))246 device_set_wakeup_capable(&pdev->dev, true);247 else248 clear_bit(RTC_FEATURE_ALARM, rtc->features);249 250 rtc->ops = &opal_rtc_ops;251 rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;252 rtc->range_max = RTC_TIMESTAMP_END_9999;253 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);254 255 return devm_rtc_register_device(rtc);256}257 258static const struct of_device_id opal_rtc_match[] = {259 {260 .compatible = "ibm,opal-rtc",261 },262 { }263};264MODULE_DEVICE_TABLE(of, opal_rtc_match);265 266static const struct platform_device_id opal_rtc_driver_ids[] = {267 {268 .name = "opal-rtc",269 },270 { }271};272MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids);273 274static struct platform_driver opal_rtc_driver = {275 .probe = opal_rtc_probe,276 .id_table = opal_rtc_driver_ids,277 .driver = {278 .name = DRVNAME,279 .of_match_table = opal_rtc_match,280 },281};282 283static int __init opal_rtc_init(void)284{285 if (!firmware_has_feature(FW_FEATURE_OPAL))286 return -ENODEV;287 288 return platform_driver_register(&opal_rtc_driver);289}290 291static void __exit opal_rtc_exit(void)292{293 platform_driver_unregister(&opal_rtc_driver);294}295 296MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");297MODULE_DESCRIPTION("IBM OPAL RTC driver");298MODULE_LICENSE("GPL");299 300module_init(opal_rtc_init);301module_exit(opal_rtc_exit);302