From c9ab6352f6ec9bc3947f03481fb8f3aa77ffcf62 Mon Sep 17 00:00:00 2001
From: CTCaer <ctcaer@gmail.com>
Date: Mon, 19 Dec 2022 05:30:23 +0200
Subject: [PATCH] bdk: rtc: add T210B01 R2P

---
 bdk/rtc/max77620-rtc.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 bdk/rtc/max77620-rtc.h | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)

diff --git a/bdk/rtc/max77620-rtc.c b/bdk/rtc/max77620-rtc.c
index 785ab4b..87cc8c4 100644
--- a/bdk/rtc/max77620-rtc.c
+++ b/bdk/rtc/max77620-rtc.c
@@ -153,3 +153,45 @@ u32 max77620_rtc_date_to_epoch(const rtc_time_t *time)
 
 	return epoch;
 }
+
+void max77620_rtc_set_reboot_reason(rtc_reboot_reason_t *rr)
+{
+	max77620_rtc_stop_alarm();
+
+	// Set reboot reason.
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM1_YEAR_REG, rr->enc.val1);
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM2_YEAR_REG, rr->enc.val2);
+
+	// Set reboot reason magic.
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM1_WEEKDAY_REG, RTC_REBOOT_REASON_MAGIC);
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM2_WEEKDAY_REG, RTC_REBOOT_REASON_MAGIC);
+
+	// Update RTC clock from RTC regs.
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_UPDATE0_REG, MAX77620_RTC_WRITE_UPDATE);
+	msleep(16);
+}
+
+bool max77620_rtc_get_reboot_reason(rtc_reboot_reason_t *rr)
+{
+	u8 magic[2];
+
+	// Get reboot reason magic.
+	magic[0] = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM1_WEEKDAY_REG);
+	magic[1] = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM2_WEEKDAY_REG);
+
+	// Magic must be correct and match on both registers.
+	if (magic[0] != RTC_REBOOT_REASON_MAGIC || magic[0] != magic[1])
+		return false;
+
+	// Reboot reason setter is expected to have updated the actual regs already.
+	rr->enc.val1 = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM1_YEAR_REG);
+	rr->enc.val2 = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM2_YEAR_REG);
+
+	// Clear magic and update actual regs.
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM1_WEEKDAY_REG, 0);
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM2_WEEKDAY_REG, 0);
+	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_UPDATE0_REG, MAX77620_RTC_WRITE_UPDATE);
+
+	// Return reboot reason. False if [config] was selected.
+	return true;
+}
diff --git a/bdk/rtc/max77620-rtc.h b/bdk/rtc/max77620-rtc.h
index 48d1b9b..b0d616d 100644
--- a/bdk/rtc/max77620-rtc.h
+++ b/bdk/rtc/max77620-rtc.h
@@ -74,10 +74,45 @@ typedef struct _rtc_time_t {
 	u16 year;
 } rtc_time_t;
 
+#define RTC_REBOOT_REASON_MAGIC 0x77 // 7-bit reg.
+
+enum {
+	REBOOT_REASON_NOP   = 0, // Use [config].
+	REBOOT_REASON_SELF  = 1, // Use autoboot_idx/autoboot_list.
+	REBOOT_REASON_MENU  = 2, // Force menu.
+	REBOOT_REASON_UMS   = 3, // Force selected UMS partition.
+	REBOOT_REASON_REC   = 4, // Set PMC_SCRATCH0_MODE_RECOVERY and reboot to self.
+	REBOOT_REASON_PANIC = 5  // Inform bootloader that panic occured if T210B01.
+};
+
+typedef struct _rtc_rr_decoded_t
+{
+	u16 reason:4;
+	u16 autoboot_idx:4;
+	u16 autoboot_list:1;
+	u16 ums_idx:3;
+} rtc_rr_decoded_t;
+
+typedef struct _rtc_rr_encoded_t
+{
+	u16 val1:6; // 6-bit reg.
+	u16 val2:6; // 6-bit reg.
+} rtc_rr_encoded_t;
+
+typedef struct _rtc_reboot_reason_t
+{
+	union {
+		rtc_rr_decoded_t dec;
+		rtc_rr_encoded_t enc;
+	};
+} rtc_reboot_reason_t;
+
 void max77620_rtc_prep_read();
 void max77620_rtc_get_time(rtc_time_t *time);
 void max77620_rtc_stop_alarm();
 void max77620_rtc_epoch_to_date(u32 epoch, rtc_time_t *time);
 u32  max77620_rtc_date_to_epoch(const rtc_time_t *time);
+void max77620_rtc_set_reboot_reason(rtc_reboot_reason_t *rr);
+bool max77620_rtc_get_reboot_reason(rtc_reboot_reason_t *rr);
 
 #endif /* _MFD_MAX77620_RTC_H_ */