mediatek/mt8183: Add RTC support

This patch implements RTC initialization.
1. initialization dcxo
2. rtc clock using dcxo 32k
3. export RTC_32K1V8_0 to SOC, export RTC_32K1V8_1 to WLAN
4. rtc register initialization
5. refactor the driver common part

BUG=b:80501386
BRANCH=none
TEST=Boots correctly on Kukui

Change-Id: Icccb9360a507fcbfd865b107cd3630e71c810d55
Signed-off-by: Ran Bi <ran.bi@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/31046
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/soc/mediatek/common/include/soc/rtc_common.h

@@ -0,0 +1,105 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 MediaTek Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#ifndef SOC_MEDIATEK_RTC_COMMON_H
+#define SOC_MEDIATEK_RTC_COMMON_H
+
+#include <assert.h>
+#include <bcd.h>
+#include <console/console.h>
+#include <delay.h>
+#include <rtc.h>
+#include <timer.h>
+
+/*
+ * Default values for RTC initialization
+ * Year (YEA)        : 1970 ~ 2037
+ * Month (MTH)       : 1 ~ 12
+ * Day of Month (DOM): 1 ~ 31
+ */
+
+enum {
+	RTC_DEFAULT_YEA = 2010,
+	RTC_DEFAULT_MTH = 1,
+	RTC_DEFAULT_DOM = 1,
+	RTC_DEFAULT_DOW = 5
+};
+
+enum {
+	RTC_2SEC_REBOOT_ENABLE  = 1,
+	RTC_2SEC_MODE   = 2
+};
+
+enum {
+	RTC_OSC32CON_UNLOCK1 = 0x1A57,
+	RTC_OSC32CON_UNLOCK2 = 0x2B68
+};
+
+enum {
+	RTC_PROT_UNLOCK1 = 0x586A,
+	RTC_PROT_UNLOCK2 = 0x9136
+};
+
+enum {
+	RTC_BBPU_KEY	= 0x43 << 8
+};
+
+enum {
+	RTC_IRQ_STA_AL	= 1U << 0,
+	RTC_IRQ_STA_TC	= 1U << 1,
+	RTC_IRQ_STA_LP	= 1U << 3
+};
+
+enum {
+	RTC_IRQ_EN_AL		= 1U << 0,
+	RTC_IRQ_EN_TC		= 1U << 1,
+	RTC_IRQ_EN_ONESHOT	= 1U << 2,
+	RTC_IRQ_EN_LP		= 1U << 3,
+	RTC_IRQ_EN_ONESHOT_AL	= RTC_IRQ_EN_ONESHOT | RTC_IRQ_EN_AL
+};
+
+enum {
+	RTC_POWERKEY1_KEY	= 0xA357,
+	RTC_POWERKEY2_KEY	= 0x67D2
+};
+
+enum {
+	RTC_SPAR0_32K_LESS	= 1U << 6
+};
+
+enum {
+	RTC_MIN_YEAR	= 1968,
+	RTC_BASE_YEAR	= 1900,
+	RTC_MIN_YEAR_OFFSET = RTC_MIN_YEAR - RTC_BASE_YEAR,
+
+	RTC_NUM_YEARS	= 128
+};
+
+enum {
+	RTC_STATE_REBOOT	= 0,
+	RTC_STATE_RECOVER	= 1,
+	RTC_STATE_INIT		= 2
+};
+
+/* external API */
+int rtc_busy_wait(void);
+int rtc_write_trigger(void);
+int rtc_writeif_unlock(void);
+void rtc_xosc_write(u16 val);
+int rtc_reg_init(void);
+u8 rtc_check_state(void);
+void rtc_boot_common(void);
+
+#endif /* SOC_MEDIATEK_RTC_COMMON_H */

src/soc/mediatek/common/rtc.c

@@ -0,0 +1,194 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 MediaTek Inc.
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <soc/rtc_common.h>
+#include <soc/rtc.h>
+#include <soc/pmic_wrap.h>
+
+/* ensure rtc write success */
+int rtc_busy_wait(void)
+{
+	struct stopwatch sw;
+	u16 bbpu;
+
+	stopwatch_init_usecs_expire(&sw, RTC_CBUSY_TIMEOUT_US);
+
+	do {
+		pwrap_read(RTC_BBPU, &bbpu);
+		/* Time > 1sec, time out and set recovery mode enable.*/
+		if (stopwatch_expired(&sw)) {
+			printk(BIOS_INFO, "[RTC] BBPU CBUSY time out !!\n");
+			return 0;
+		}
+	} while (bbpu & RTC_BBPU_CBUSY);
+
+	return 1;
+}
+
+int rtc_write_trigger(void)
+{
+	pwrap_write(RTC_WRTGR, 1);
+	return rtc_busy_wait();
+}
+
+/* unlock rtc write interface */
+int rtc_writeif_unlock(void)
+{
+	pwrap_write(RTC_PROT, RTC_PROT_UNLOCK1);
+	if (!rtc_write_trigger())
+		return 0;
+	pwrap_write(RTC_PROT, RTC_PROT_UNLOCK2);
+	if (!rtc_write_trigger())
+		return 0;
+
+	return 1;
+}
+
+/* set rtc time */
+int rtc_set(const struct rtc_time *time)
+{
+	return -1;
+}
+
+/* get rtc time */
+int rtc_get(struct rtc_time *time)
+{
+	u16 value;
+
+	pwrap_read(RTC_TC_SEC, &value);
+	time->sec = value;
+	pwrap_read(RTC_TC_MIN, &value);
+	time->min = value;
+	pwrap_read(RTC_TC_HOU, &value);
+	time->hour = value;
+	pwrap_read(RTC_TC_DOM, &value);
+	time->mday = value;
+	pwrap_read(RTC_TC_MTH, &value);
+	time->mon = value;
+	pwrap_read(RTC_TC_YEA, &value);
+	time->year = (value + RTC_MIN_YEAR_OFFSET) % 100;
+
+	return 0;
+}
+
+/* set rtc xosc setting */
+void rtc_xosc_write(u16 val)
+{
+	u16 bbpu;
+
+	pwrap_write(RTC_OSC32CON, RTC_OSC32CON_UNLOCK1);
+	udelay(200);
+	pwrap_write(RTC_OSC32CON, RTC_OSC32CON_UNLOCK2);
+	udelay(200);
+
+	pwrap_write(RTC_OSC32CON, val);
+	udelay(200);
+
+	pwrap_read(RTC_BBPU, &bbpu);
+	bbpu |= RTC_BBPU_KEY | RTC_BBPU_RELOAD;
+	pwrap_write(RTC_BBPU, bbpu);
+	rtc_write_trigger();
+}
+
+/* initialize rtc related registers */
+int rtc_reg_init(void)
+{
+	u16 irqsta;
+
+	pwrap_write(RTC_IRQ_EN, 0);
+	pwrap_write(RTC_CII_EN, 0);
+	pwrap_write(RTC_AL_MASK, 0);
+	pwrap_write(RTC_AL_YEA, 1970 - RTC_MIN_YEAR);
+	pwrap_write(RTC_AL_MTH, 1);
+	pwrap_write(RTC_AL_DOM, 1);
+	pwrap_write(RTC_AL_DOW, 4);
+	pwrap_write(RTC_AL_HOU, 0);
+	pwrap_write(RTC_AL_MIN, 0);
+	pwrap_write(RTC_AL_SEC, 0);
+
+	pwrap_write(RTC_DIFF, 0);
+	pwrap_write(RTC_CALI, 0);
+	if (!rtc_write_trigger())
+		return 0;
+
+	pwrap_read(RTC_IRQ_STA, &irqsta);  /* read clear */
+
+	/* init time counters after resetting RTC_DIFF and RTC_CALI */
+	pwrap_write(RTC_TC_YEA, RTC_DEFAULT_YEA - RTC_MIN_YEAR);
+	pwrap_write(RTC_TC_MTH, RTC_DEFAULT_MTH);
+	pwrap_write(RTC_TC_DOM, RTC_DEFAULT_DOM);
+	pwrap_write(RTC_TC_DOW, RTC_DEFAULT_DOW);
+	pwrap_write(RTC_TC_HOU, 0);
+	pwrap_write(RTC_TC_MIN, 0);
+	pwrap_write(RTC_TC_SEC, 0);
+
+	return rtc_write_trigger();
+}
+
+u8 rtc_check_state(void)
+{
+	u16 con;
+	u16 pwrky1;
+	u16 pwrky2;
+
+	pwrap_read(RTC_CON, &con);
+	pwrap_read(RTC_POWERKEY1, &pwrky1);
+	pwrap_read(RTC_POWERKEY2, &pwrky2);
+
+	if (con & RTC_CON_LPSTA_RAW)
+		return RTC_STATE_INIT;
+
+	if (!rtc_busy_wait())
+		return RTC_STATE_RECOVER;
+
+	if (!rtc_writeif_unlock())
+		return RTC_STATE_RECOVER;
+
+	if (pwrky1 != RTC_POWERKEY1_KEY || pwrky2 != RTC_POWERKEY2_KEY)
+		return RTC_STATE_INIT;
+	else
+		return RTC_STATE_REBOOT;
+}
+
+void rtc_boot_common(void)
+{
+	u16 bbpu;
+	u16 con;
+	u16 irqsta;
+
+	switch (rtc_check_state()) {
+	case RTC_STATE_REBOOT:
+		pwrap_write_field(RTC_BBPU, RTC_BBPU_KEY | RTC_BBPU_RELOAD,
+				  0xFFFF, 0);
+		rtc_write_trigger();
+		rtc_osc_init();
+		break;
+	case RTC_STATE_RECOVER:
+		rtc_init(1);
+		break;
+	case RTC_STATE_INIT:
+	default:
+		if (!rtc_init(0))
+			rtc_init(1);
+		break;
+	}
+
+	pwrap_read(RTC_IRQ_STA, &irqsta);  /* Read clear */
+	pwrap_read(RTC_BBPU, &bbpu);
+	pwrap_read(RTC_CON, &con);
+
+	printk(BIOS_INFO, "[RTC] irqsta = %x", irqsta);
+	printk(BIOS_INFO, " bbpu = %#x, con = %#x\n", bbpu, con);
+}