[PATCH 02/20] global: k3: use gd to store the resume state

[Richard Genoud (TI)]

For J7200, J784s4, J721e, j722s, j721s2 SoCs, the everything is shutdown
at suspend but the PMIC and the DDR.
In order for U-Boot SPL to know that it is resuming from suspend and not
booting, a flag is set in a PMIC register.
So, at startup, U-Boot will read the PMIC register and deduce if the
board is resuming from suspend or not.

This state (resuming or not) is consulted at several places (in
board_init_f() and in k3_ddrss_probe().
As it takes some time to read a i2c register, it's best to cache the
information.
But, as stated by the README, in board_init_f(), the BSS is not
available, so we cannot use global/static variables, only stack
variables and global_data.

Thus, we use gd to store the resume state of the board.

Signed-off-by: Richard Genoud (TI) <richard.genoud at bootlin.com>
---
 arch/arm/include/asm/global_data.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index b2ec450f9002..f343d3396c1c 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -14,6 +14,14 @@
 #include <linux/types.h>
 #include <asm/u-boot.h>
 
+#if (IS_ENABLED(CONFIG_SPL_BUILD) && IS_ENABLED(CONFIG_ARCH_K3))
+enum k3_resume_state {
+	K3_RESUME_STATE_UNKNOWN = 0,
+	K3_RESUME_STATE_BOOTING,
+	K3_RESUME_STATE_RESUMING
+};
+#endif
+
 /* Architecture-specific global data */
 struct arch_global_data {
 #if defined(CONFIG_FSL_ESDHC) || defined(CONFIG_FSL_ESDHC_IMX)
@@ -108,8 +116,19 @@ struct arch_global_data {
 #ifdef CONFIG_SMBIOS
 	ulong smbios_start;		/* Start address of SMBIOS table */
 #endif
+#if (IS_ENABLED(CONFIG_SPL_BUILD) && IS_ENABLED(CONFIG_ARCH_K3))
+	enum k3_resume_state k3_resuming;
+#endif
 };
 
+#if (IS_ENABLED(CONFIG_SPL_BUILD) && IS_ENABLED(CONFIG_ARCH_K3))
+#define gd_k3_resuming() gd->arch.k3_resuming
+#define gd_set_k3_resuming(state) gd->arch.k3_resuming = (state)
+#else
+#define gd_k3_resuming() 0
+#define gd_set_k3_resuming(state)
+#endif
+
 #include <asm-generic/global_data.h>
 
 #if defined(__clang__) || defined(LTO_ENABLE)