302 lines
6.9 KiB
C
302 lines
6.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* IBM OPAL RTC driver
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* Copyright (C) 2014 IBM
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#define DRVNAME "rtc-opal"
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#include <linux/module.h>
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#include <linux/err.h>
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#include <linux/rtc.h>
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#include <linux/delay.h>
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#include <linux/bcd.h>
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#include <linux/platform_device.h>
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#include <linux/of.h>
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#include <asm/opal.h>
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#include <asm/firmware.h>
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static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
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{
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tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +
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bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
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tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1;
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tm->tm_mday = bcd2bin(y_m_d & 0xff);
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tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);
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tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff);
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tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff);
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tm->tm_wday = -1;
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}
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static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms)
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{
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*y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
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*y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
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*y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
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*y_m_d |= ((u32)bin2bcd(tm->tm_mday));
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*h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
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*h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
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*h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
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}
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static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm)
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{
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s64 rc = OPAL_BUSY;
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int retries = 10;
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u32 y_m_d;
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u64 h_m_s_ms;
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__be32 __y_m_d;
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__be64 __h_m_s_ms;
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while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
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rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
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if (rc == OPAL_BUSY_EVENT) {
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msleep(OPAL_BUSY_DELAY_MS);
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opal_poll_events(NULL);
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} else if (rc == OPAL_BUSY) {
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msleep(OPAL_BUSY_DELAY_MS);
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} else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) {
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if (retries--) {
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msleep(10); /* Wait 10ms before retry */
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rc = OPAL_BUSY; /* go around again */
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}
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}
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}
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if (rc != OPAL_SUCCESS)
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return -EIO;
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y_m_d = be32_to_cpu(__y_m_d);
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h_m_s_ms = be64_to_cpu(__h_m_s_ms);
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opal_to_tm(y_m_d, h_m_s_ms, tm);
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return 0;
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}
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static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm)
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{
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s64 rc = OPAL_BUSY;
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int retries = 10;
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u32 y_m_d = 0;
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u64 h_m_s_ms = 0;
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tm_to_opal(tm, &y_m_d, &h_m_s_ms);
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while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
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rc = opal_rtc_write(y_m_d, h_m_s_ms);
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if (rc == OPAL_BUSY_EVENT) {
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msleep(OPAL_BUSY_DELAY_MS);
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opal_poll_events(NULL);
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} else if (rc == OPAL_BUSY) {
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msleep(OPAL_BUSY_DELAY_MS);
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} else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) {
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if (retries--) {
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msleep(10); /* Wait 10ms before retry */
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rc = OPAL_BUSY; /* go around again */
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}
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}
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}
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return rc == OPAL_SUCCESS ? 0 : -EIO;
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}
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/*
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* TPO Timed Power-On
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*
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* TPO get/set OPAL calls care about the hour and min and to make it consistent
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* with the rtc utility time conversion functions, we use the 'u64' to store
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* its value and perform bit shift by 32 before use..
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*/
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static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
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{
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__be32 __y_m_d, __h_m;
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struct opal_msg msg;
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int rc, token;
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u64 h_m_s_ms;
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u32 y_m_d;
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token = opal_async_get_token_interruptible();
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if (token < 0) {
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if (token != -ERESTARTSYS)
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pr_err("Failed to get the async token\n");
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return token;
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}
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rc = opal_tpo_read(token, &__y_m_d, &__h_m);
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if (rc != OPAL_ASYNC_COMPLETION) {
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rc = -EIO;
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goto exit;
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}
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rc = opal_async_wait_response(token, &msg);
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if (rc) {
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rc = -EIO;
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goto exit;
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}
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rc = opal_get_async_rc(msg);
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if (rc != OPAL_SUCCESS) {
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rc = -EIO;
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goto exit;
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}
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y_m_d = be32_to_cpu(__y_m_d);
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h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32);
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/* check if no alarm is set */
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if (y_m_d == 0 && h_m_s_ms == 0) {
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pr_debug("No alarm is set\n");
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rc = -ENOENT;
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goto exit;
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} else {
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pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms);
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}
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opal_to_tm(y_m_d, h_m_s_ms, &alarm->time);
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exit:
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opal_async_release_token(token);
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return rc;
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}
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/* Set Timed Power-On */
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static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
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{
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u64 h_m_s_ms = 0;
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struct opal_msg msg;
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u32 y_m_d = 0;
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int token, rc;
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/* if alarm is enabled */
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if (alarm->enabled) {
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tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms);
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pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms);
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} else {
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pr_debug("Alarm getting disabled\n");
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}
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token = opal_async_get_token_interruptible();
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if (token < 0) {
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if (token != -ERESTARTSYS)
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pr_err("Failed to get the async token\n");
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return token;
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}
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/* TPO, we care about hour and minute */
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rc = opal_tpo_write(token, y_m_d,
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(u32)((h_m_s_ms >> 32) & 0xffff0000));
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if (rc != OPAL_ASYNC_COMPLETION) {
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rc = -EIO;
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goto exit;
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}
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rc = opal_async_wait_response(token, &msg);
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if (rc) {
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rc = -EIO;
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goto exit;
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}
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rc = opal_get_async_rc(msg);
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if (rc != OPAL_SUCCESS)
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rc = -EIO;
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exit:
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opal_async_release_token(token);
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return rc;
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}
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static int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled)
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{
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struct rtc_wkalrm alarm = { .enabled = 0 };
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/*
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* TPO is automatically enabled when opal_set_tpo_time() is called with
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* non-zero rtc-time. We only handle disable case which needs to be
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* explicitly told to opal.
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*/
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return enabled ? 0 : opal_set_tpo_time(dev, &alarm);
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}
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static const struct rtc_class_ops opal_rtc_ops = {
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.read_time = opal_get_rtc_time,
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.set_time = opal_set_rtc_time,
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.read_alarm = opal_get_tpo_time,
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.set_alarm = opal_set_tpo_time,
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.alarm_irq_enable = opal_tpo_alarm_irq_enable,
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};
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static int opal_rtc_probe(struct platform_device *pdev)
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{
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struct rtc_device *rtc;
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rtc = devm_rtc_allocate_device(&pdev->dev);
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if (IS_ERR(rtc))
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return PTR_ERR(rtc);
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if (pdev->dev.of_node &&
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(of_property_read_bool(pdev->dev.of_node, "wakeup-source") ||
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of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */))
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device_set_wakeup_capable(&pdev->dev, true);
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else
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clear_bit(RTC_FEATURE_ALARM, rtc->features);
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rtc->ops = &opal_rtc_ops;
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rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
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rtc->range_max = RTC_TIMESTAMP_END_9999;
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clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
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return devm_rtc_register_device(rtc);
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}
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static const struct of_device_id opal_rtc_match[] = {
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{
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.compatible = "ibm,opal-rtc",
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},
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{ }
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};
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MODULE_DEVICE_TABLE(of, opal_rtc_match);
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static const struct platform_device_id opal_rtc_driver_ids[] = {
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{
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.name = "opal-rtc",
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},
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{ }
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};
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MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids);
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static struct platform_driver opal_rtc_driver = {
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.probe = opal_rtc_probe,
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.id_table = opal_rtc_driver_ids,
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.driver = {
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.name = DRVNAME,
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.of_match_table = opal_rtc_match,
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},
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};
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static int __init opal_rtc_init(void)
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{
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if (!firmware_has_feature(FW_FEATURE_OPAL))
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return -ENODEV;
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return platform_driver_register(&opal_rtc_driver);
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}
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static void __exit opal_rtc_exit(void)
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{
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platform_driver_unregister(&opal_rtc_driver);
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}
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MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
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MODULE_DESCRIPTION("IBM OPAL RTC driver");
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MODULE_LICENSE("GPL");
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module_init(opal_rtc_init);
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module_exit(opal_rtc_exit);
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