stm32mp1: save boot information in backup registers

This will be used by BL33 to get boot device and instance.
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Mathieu Belou <mathieu.belou@st.com>
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>

plat/st/stm32mp1/bl2_plat_setup.c

@@ -19,6 +19,7 @@
 #include <stm32mp1_clk.h>
 #include <stm32mp1_dt.h>
 #include <stm32mp1_private.h>
+#include <stm32mp1_context.h>
 #include <stm32mp1_pwr.h>
 #include <stm32mp1_rcc.h>
 #include <string.h>
@@ -37,6 +38,9 @@ void bl2_platform_setup(void)
 
 void bl2_el3_plat_arch_setup(void)
 {
+	boot_api_context_t *boot_context =
+		(boot_api_context_t *)stm32mp1_get_boot_ctx_address();
+
 	/*
 	 * Disable the backup domain write protection.
 	 * The protection is enable at each reset by hardware
@@ -90,5 +94,11 @@ void bl2_el3_plat_arch_setup(void)
 		panic();
 	}
 
+	if (stm32_save_boot_interface(boot_context->boot_interface_selected,
+				      boot_context->boot_interface_instance) !=
+	    0) {
+		ERROR("Cannot save boot interface\n");
+	}
+
 	stm32mp1_io_setup();
 }

plat/st/stm32mp1/include/stm32mp1_context.h

+/*
+ * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __STM32MP1_CONTEXT_H__
+#define __STM32MP1_CONTEXT_H__
+
+#include <stdint.h>
+
+int stm32_save_boot_interface(uint32_t interface, uint32_t instance);
+
+#endif /* __STM32MP1_CONTEXT_H__ */

plat/st/stm32mp1/platform.mk

@@ -43,6 +43,7 @@ PLAT_BL_COMMON_SOURCES	+=	${LIBFDT_SRCS}						\
 				drivers/st/clk/stm32mp1_clkfunc.c			\
 				drivers/st/gpio/stm32_gpio.c				\
 				drivers/st/reset/stm32mp1_reset.c			\
+				plat/st/stm32mp1/stm32mp1_context.c			\
 				plat/st/stm32mp1/stm32mp1_dt.c				\
 				plat/st/stm32mp1/stm32mp1_helper.S
 

plat/st/stm32mp1/stm32mp1_context.c

+/*
+ * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <dt-bindings/clock/stm32mp1-clks.h>
+#include <errno.h>
+#include <mmio.h>
+#include <platform_def.h>
+#include <stm32mp1_clk.h>
+#include <stm32mp1_context.h>
+
+#define TAMP_BOOT_ITF_BACKUP_REG_ID	U(20)
+#define TAMP_BOOT_ITF_MASK		U(0x0000FF00)
+#define TAMP_BOOT_ITF_SHIFT		8
+
+int stm32_save_boot_interface(uint32_t interface, uint32_t instance)
+{
+	uint32_t tamp_clk_off = 0;
+	uint32_t bkpr_itf_idx = tamp_bkpr(TAMP_BOOT_ITF_BACKUP_REG_ID);
+
+	if (!stm32mp1_clk_is_enabled(RTCAPB)) {
+		tamp_clk_off = 1;
+		if (stm32mp1_clk_enable(RTCAPB) != 0) {
+			return -EINVAL;
+		}
+	}
+
+	mmio_clrsetbits_32(bkpr_itf_idx,
+			   TAMP_BOOT_ITF_MASK,
+			   ((interface << 4) | (instance & 0xFU)) <<
+			   TAMP_BOOT_ITF_SHIFT);
+
+	if (tamp_clk_off != 0U) {
+		if (stm32mp1_clk_disable(RTCAPB) != 0) {
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}

plat/st/stm32mp1/stm32mp1_def.h

@@ -157,6 +157,19 @@ enum ddr_type {
 #define STM32MP1_EMMC_NORMAL_SPEED_MAX_FREQ	26000000	/*26 MHz*/
 #define STM32MP1_EMMC_HIGH_SPEED_MAX_FREQ	52000000	/*52 MHz*/
 
+/*******************************************************************************
+ * STM32MP1 TAMP
+ ******************************************************************************/
+#define TAMP_BASE			U(0x5C00A000)
+#define TAMP_BKP_REGISTER_BASE		(TAMP_BASE + U(0x100))
+
+#if !(defined(__LINKER__) || defined(__ASSEMBLY__))
+static inline uint32_t tamp_bkpr(uint32_t idx)
+{
+	return TAMP_BKP_REGISTER_BASE + (idx << 2);
+}
+#endif
+
 /*******************************************************************************
  * STM32MP1 DDRCTRL
  ******************************************************************************/