[PATCH 22/42] imx9: soc: support reset cause

[Peng Fan (OSS)]

From: Peng Fan <peng....@nxp.com>

Support print reset cause. Since SRSR is not accessible from non-secure
world, so first save it to grp0, then read it in non-secure world.

Signed-off-by: Peng Fan <peng....@nxp.com>
---
 arch/arm/mach-imx/imx9/soc.c | 59 ++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/arch/arm/mach-imx/imx9/soc.c b/arch/arm/mach-imx/imx9/soc.c
index e4e9eca101e..dcabfe34aca 100644
--- a/arch/arm/mach-imx/imx9/soc.c
+++ b/arch/arm/mach-imx/imx9/soc.c
@@ -19,6 +19,8 @@
 #include <asm/mach-imx/boot_mode.h>
 #include <asm/mach-imx/syscounter.h>
 #include <asm/armv8/mmu.h>
+#include <dm/device.h>
+#include <dm/device_compat.h>
 #include <dm/uclass.h>
 #include <env.h>
 #include <env_internal.h>
@@ -408,6 +410,18 @@ void get_board_serial(struct tag_serialnr *serialnr)
 }
 #endif
 
+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]);
+}
+
 int arch_cpu_init(void)
 {
        if (IS_ENABLED(CONFIG_SPL_BUILD)) {
@@ -417,6 +431,9 @@ int arch_cpu_init(void)
                clock_init();
 
                trdc_early_init();
+
+               /* Save SRC SRSR to GPR1 and clear it */
+               save_reset_cause();
        }
 
        return 0;
@@ -650,3 +667,45 @@ int m33_prepare(void)
 
        return 0;
 }
+
+int psci_sysreset_get_status(struct udevice *dev, char *buf, int size)
+{
+       static const char *reset_cause[] = {
+               "POR ",
+               "JTAG ",
+               "IPP USER ",
+               "WDOG1 ",
+               "WDOG2 ",
+               "WDOG3 ",
+               "WDOG4 ",
+               "WDOG5 ",
+               "TEMPSENSE ",
+               "CSU ",
+               "JTAG_SW ",
+               "M33_REQ ",
+               "M33_LOCKUP ",
+               "UNK ",
+               "UNK ",
+               "UNK "
+       };
+
+       struct src_general_regs *src = (struct src_general_regs 
*)SRC_GLOBAL_RBASE;
+       u32 srsr;
+       u32 i;
+       int res;
+
+       srsr = readl(&src->gpr[0]);
+
+       for (i = ARRAY_SIZE(reset_cause); i > 0; i--) {
+               if (srsr & (BIT(i - 1)))
+                       break;
+       }
+
+       res = snprintf(buf, size, "Reset Status: %s\n", i ? reset_cause[i - 1] 
: "unknown reset");
+       if (res < 0) {
+               dev_err(dev, "Could not write reset status message (err = 
%d)\n", res);
+               return -EIO;
+       }
+
+       return 0;
+}
-- 
2.40.0