[U-Boot] [PATCH v1 3/3] imx: cpu.c: give access to reset cause in spl

[Marcel Ziswiler]

From: Max Krummenacher <max.krummenacher at toradex.com>

This makes get_imx_reset_cause() accessible in SPL, but keeps the SRSR
register content intact so that U-Boot proper can evaluated the
reset_cause again should this be needed.

Signed-off-by: Max Krummenacher <max.krummenacher at toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler at toradex.com>

---

 arch/arm/mach-imx/cpu.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/arch/arm/mach-imx/cpu.c b/arch/arm/mach-imx/cpu.c
index 80d9ff48a4..6b83f92662 100644
--- a/arch/arm/mach-imx/cpu.c
+++ b/arch/arm/mach-imx/cpu.c
@@ -25,19 +25,27 @@
 #include <fsl_esdhc.h>
 #endif
 
-#if defined(CONFIG_DISPLAY_CPUINFO) && !defined(CONFIG_SPL_BUILD)
 static u32 reset_cause = -1;
 
-static char *get_reset_cause(void)
+u32 get_imx_reset_cause(void)
 {
-	u32 cause;
 	struct src *src_regs = (struct src *)SRC_BASE_ADDR;
 
-	cause = readl(&src_regs->srsr);
-	writel(cause, &src_regs->srsr);
-	reset_cause = cause;
+	if (reset_cause == -1) {
+		reset_cause = readl(&src_regs->srsr);
+/* preserve the value for U-Boot proper */
+#if !defined(CONFIG_SPL_BUILD)
+		writel(reset_cause, &src_regs->srsr);
+#endif
+	}
+
+	return reset_cause;
+}
 
-	switch (cause) {
+#if defined(CONFIG_DISPLAY_CPUINFO) && !defined(CONFIG_SPL_BUILD)
+static char *get_reset_cause(void)
+{
+	switch (get_imx_reset_cause()) {
 	case 0x00001:
 	case 0x00011:
 		return "POR";
@@ -77,11 +85,6 @@ static char *get_reset_cause(void)
 		return "unknown reset";
 	}
 }
-
-u32 get_imx_reset_cause(void)
-{
-	return reset_cause;
-}
 #endif
 
 #if defined(CONFIG_MX53) || defined(CONFIG_MX6)
-- 
2.20.1