From 8dd52f15df34c13a3987c401ec025039c35ba930 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Lothar=20Wa=C3=9Fmann?= <LW@KARO-electronics.de>
Date: Thu, 9 May 2019 15:47:12 +0200
Subject: [PATCH] arm: mx6: implement refcounting for the ocotp clock and use
 'fuse_read()' rather than 'readl()' to access the HAB fuses

---
 arch/arm/cpu/armv7/mx6/clock.c | 10 ++++++++++
 arch/arm/cpu/armv7/mx6/hab.c   | 16 +++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c
index c3c9c5e651..4f2a4b97b7 100644
--- a/arch/arm/cpu/armv7/mx6/clock.c
+++ b/arch/arm/cpu/armv7/mx6/clock.c
@@ -138,6 +138,16 @@ static inline int wait_pll_lock(u32 *reg)
 void enable_ocotp_clk(unsigned char enable)
 {
 	u32 reg;
+	static int enabled __attribute__((section(".data")));
+
+	if (enabled < 0) {
+		printf("ERROR: unbalanced enable/disable ocotp_clk\n");
+		hang();
+	}
+	if (enable && enabled++)
+		return;
+	if (!enable && --enabled)
+		return;
 
 	reg = __raw_readl(&imx_ccm->CCGR2);
 	if (enable)
diff --git a/arch/arm/cpu/armv7/mx6/hab.c b/arch/arm/cpu/armv7/mx6/hab.c
index aaf0d33a42..83b1e26a10 100644
--- a/arch/arm/cpu/armv7/mx6/hab.c
+++ b/arch/arm/cpu/armv7/mx6/hab.c
@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <fuse.h>
 #include <asm/io.h>
 #include <asm/system.h>
 #include <asm/arch/clock.h>
@@ -175,13 +176,14 @@ uint8_t hab_engines[ARRAY_SIZE(eng_str)] = {
 
 bool is_hab_enabled(void)
 {
-	struct ocotp_regs *ocotp = (struct ocotp_regs *)OCOTP_BASE_ADDR;
-	struct fuse_bank *bank = &ocotp->bank[0];
-	struct fuse_bank0_regs *fuse =
-		(struct fuse_bank0_regs *)bank->fuse_regs;
-	uint32_t reg = readl(&fuse->cfg5);
+	uint32_t reg;
 	static int first = 1;
 
+	if (fuse_read(0, 6, &reg)) {
+		printf("Failed to read SECURE_BOOT fuse\n");
+		return 0;
+	}
+
 	if (first) {
 		debug("rvt_base=%p\n", hab_rvt_base());
 		debug("hab_rvt_entry=%p\n", hab_rvt_entry_p);
@@ -253,8 +255,10 @@ int get_hab_status(void)
 		puts("Secure boot disabled\n");
 
 	/* Check HAB status */
+	enable_ocotp_clk(1);
 	config = state = 0; /* ROM code assumes short enums! */
 	ret = hab_rvt_report_status(&config, &state);
+	enable_ocotp_clk(0);
 	printf("HAB Configuration: 0x%02x, HAB State: 0x%02x\n",
 		config, state);
 	if (ret != HAB_SUCCESS) {
@@ -284,6 +288,7 @@ static inline enum hab_status hab_init(void)
 {
 	enum hab_status ret;
 
+	enable_ocotp_clk(1);
 	if (!is_hab_enabled()) {
 		puts("hab fuse not enabled\n");
 		return HAB_FAILURE;
@@ -310,6 +315,7 @@ static inline enum hab_status hab_exit(void)
 		printf("hab exit function failed: %02x\n", ret);
 
 	hab_caam_clock_enable(0);
+	enable_ocotp_clk(0);
 
 	return ret;
 }
-- 
2.39.2