From b67d88aecbd3396ef35c952a1c5af0734f7663aa Mon Sep 17 00:00:00 2001
From: Kapil Porwal <kapilporwal@google.com>
Date: Mon, 25 Aug 2025 09:44:44 +0530
Subject: [PATCH] mb/google/bluey: Enable PMIC based slow charging in romstage

Enable PMIC based slow charging in romstage until we have fast charging
solution enabled.

BUG=b:438004604
TEST=Verify battery charging during romstage.

Change-Id: Idb8ea7151a2a467194aee2b357d8a5f24e691717
Signed-off-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/88928
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
---
 src/mainboard/google/bluey/romstage.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/mainboard/google/bluey/romstage.c b/src/mainboard/google/bluey/romstage.c
index b76dfba1f2..67d19aa1e6 100644
--- a/src/mainboard/google/bluey/romstage.c
+++ b/src/mainboard/google/bluey/romstage.c
@@ -5,9 +5,32 @@
 #include <gpio.h>
 #include <soc/aop_common.h>
 #include <soc/qclib_common.h>
+#include <soc/qcom_spmi.h>
 #include <soc/shrm.h>
 #include <soc/watchdog.h>
 
+#define SMB1_SLAVE_ID 0x07
+#define SMB2_SLAVE_ID 0x0A
+#define SCHG_CHGR_MAX_FAST_CHARGE_CURRENT_CFG 0x2666
+#define SMB1_CHGR_MAX_FCC_CFG ((SMB1_SLAVE_ID << 16) | SCHG_CHGR_MAX_FAST_CHARGE_CURRENT_CFG)
+#define SMB2_CHGR_MAX_FCC_CFG ((SMB2_SLAVE_ID << 16) | SCHG_CHGR_MAX_FAST_CHARGE_CURRENT_CFG)
+#define SCHG_CHGR_CHARGING_ENABLE_CMD 0x2642
+#define SMB1_CHGR_CHRG_EN_CMD ((SMB1_SLAVE_ID << 16) | SCHG_CHGR_CHARGING_ENABLE_CMD)
+#define SMB2_CHGR_CHRG_EN_CMD ((SMB2_SLAVE_ID << 16) | SCHG_CHGR_CHARGING_ENABLE_CMD)
+
+#define FCC_1A_STEP_50MA 0x14
+#define CHRG_ENABLE 0x01
+
+static void enable_battery_charging(void)
+{
+	/* Configure FCC and enable charging */
+	printk(BIOS_INFO, "Use slow charging without fast charge support\n");
+	spmi_write8(SMB1_CHGR_MAX_FCC_CFG, FCC_1A_STEP_50MA);
+	spmi_write8(SMB2_CHGR_MAX_FCC_CFG, FCC_1A_STEP_50MA);
+	spmi_write8(SMB1_CHGR_CHRG_EN_CMD, CHRG_ENABLE);
+	spmi_write8(SMB2_CHGR_CHRG_EN_CMD, CHRG_ENABLE);
+}
+
 void platform_romstage_main(void)
 {
 	/* Watchdog must be checked first to avoid erasing watchdog info later. */
@@ -22,6 +45,8 @@ void platform_romstage_main(void)
 
 	qclib_rerun();
 
+	enable_battery_charging();
+
 	/*
 	 * Enable this power rail now for FPMCU stability prior to
 	 * its reset being deasserted in ramstage. This applies