ARM: OMAP4/5: Add generic board detection hook

Many TI EVMs have capability to store relevant board information
such as DDR description in EEPROM. Further many pad configuration
variations can occur as part of revision changes in the platform.
In-order to support these at runtime, we for a board detection hook
which is available for override from board files that may desire to do
so.

NOTE: All TI EVMs are capable of detecting board information based on
early clocks that are configured. However, in case of additional needs
this can be achieved within the override logic from within the board
file.

Signed-off-by: Steve Kipisz <s-kipisz2@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/cpu/armv7/omap-common/hwinit-common.c

@@ -97,6 +97,16 @@ int arch_cpu_init(void)
 }
 #endif /* CONFIG_ARCH_CPU_INIT */
 
+/**
+ * do_board_detect() - Detect board description
+ *
+ * Function to detect board description. This is expected to be
+ * overridden in the SoC family board file where desired.
+ */
+void __weak do_board_detect(void)
+{
+}
+
 /*
  * Routine: s_init
  * Description: Does early system init of watchdog, muxing,  andclocks
@@ -128,6 +138,7 @@ void s_init(void)
 	do_io_settings();
 #endif
 	setup_early_clocks();
+	do_board_detect();
 	prcm_init();
 }
 

arch/arm/include/asm/arch-omap4/sys_proto.h

@@ -39,6 +39,7 @@ u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
 void setup_early_clocks(void);
 void prcm_init(void);
+void do_board_detect(void);
 void bypass_dpll(u32 const base);
 void freq_update_core(void);
 u32 get_sys_clk_freq(void);

arch/arm/include/asm/arch-omap5/sys_proto.h

@@ -50,6 +50,7 @@ u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
 void setup_early_clocks(void);
 void prcm_init(void);
+void do_board_detect(void);
 void bypass_dpll(u32 const base);
 void freq_update_core(void);
 u32 get_sys_clk_freq(void);