[PATCH 14/41] imx9: add reset cause print

[Peng Fan (OSS)]

From: Peng Fan <peng.fan at nxp.com>

Add reset cause print to u-boot log on i.MX93.
Since the SRC GENERAL registers are read only for non-secure mode.
We have to clear SRSR in secure mode (SPL) and pass the value to
non-secure mode via GPR1 register.

Signed-off-by: Ye Li <ye.li at nxp.com>
Signed-off-by: Peng Fan <peng.fan at nxp.com>
---
 arch/arm/mach-imx/imx9/soc.c | 54 ++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/arch/arm/mach-imx/imx9/soc.c b/arch/arm/mach-imx/imx9/soc.c
index ed75be6e195..60044155a63 100644
--- a/arch/arm/mach-imx/imx9/soc.c
+++ b/arch/arm/mach-imx/imx9/soc.c
@@ -461,10 +461,59 @@ err:
 	printf("%s: fuse read err: %d\n", __func__, ret);
 }
 
+const char *reset_cause[] = {
+	"POR ",
+	"JTAG ",
+	"IPP USER ",
+	"WDOG1 ",
+	"WDOG2 ",
+	"WDOG3 ",
+	"WDOG4 ",
+	"WDOG5 ",
+	"TEMPSENSE ",
+	"CSU ",
+	"JTAG_SW ",
+	"M33_REQ ",
+	"M33_LOCKUP "
+	"UNK ",
+	"UNK ",
+	"UNK "
+};
+
+static void save_reset_cause(void)
+{
+	struct src_general_regs *src = (struct src_general_regs *)SRC_GLOBAL_RBASE;
+	u32 srsr = readl(&src->srsr);
+
+	/* clear srsr in sec mode */
+	writel(srsr, &src->srsr);
+	/* Save value to GPR1 to pass to nonsecure */
+	writel(srsr, &src->gpr[0]);
+}
+
+static const char *get_reset_cause(u32 *srsr_ret)
+{
+	struct src_general_regs *src = (struct src_general_regs *)SRC_GLOBAL_RBASE;
+	u32 srsr;
+	u32 i;
+
+	srsr = readl(&src->gpr[0]);
+	if (srsr_ret)
+		*srsr_ret = srsr;
+
+	for (i = ARRAY_SIZE(reset_cause); i > 0; i--) {
+		if (srsr & (BIT(i - 1)))
+			return reset_cause[i - 1];
+	}
+
+	return "unknown reset";
+}
+
 int print_cpuinfo(void)
 {
 	u32 cpurev, max_freq;
 	int minc, maxc;
+	u32 ssrs_ret;
 
 	cpurev = get_cpu_rev();
 
@@ -495,6 +544,8 @@ int print_cpuinfo(void)
 	}
 	printf("(%dC to %dC)", minc, maxc);
 
+	printf("\nReset cause: %s (0x%x)\n", get_reset_cause(&ssrs_ret), ssrs_ret);
+
 	return 0;
 }
 
@@ -528,6 +579,9 @@ int arch_cpu_init(void)
 		clock_init();
 
 		trdc_early_init();
+
+		/* Save SRC SRSR to GPR1 and clear it */
+		save_reset_cause();
 	}
 
 	return 0;
-- 
2.36.0