[PATCH 2/7] sandbox: power: handle missing stickypage gracefully

[Ahmad Fatoum <ahmad@a3f.at>]

To enable simulation of $global.system.reset in sandbox, the power
driver writes the reset-source into the stickypage for readout during
subsequent barebox startup. This is an optional feature, so it should
happen before watchdog registration, but not break watchdog operation if
not available.

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
---
 arch/sandbox/board/power.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/sandbox/board/power.c b/arch/sandbox/board/power.c
index 51f0968447c4..4adc8d7455fc 100644
--- a/arch/sandbox/board/power.c
+++ b/arch/sandbox/board/power.c
@@ -5,7 +5,7 @@
 #include <poweroff.h>
 #include <restart.h>
 #include <mach/linux.h>
-#include <reset_source.h>
+#include <asm/reset_source.h>
 #include <linux/nvmem-consumer.h>
 
 struct sandbox_power {
@@ -18,7 +18,8 @@ static void sandbox_poweroff(struct poweroff_handler *poweroff)
 {
 	struct sandbox_power *power = container_of(poweroff, struct sandbox_power, poweroff);
 
-	nvmem_cell_write(power->reset_source_cell, &(u8) { RESET_POR }, 1);
+	sandbox_save_reset_source(power->reset_source_cell, RESET_POR);
+
 	linux_exit();
 }
 
@@ -29,11 +30,9 @@ static void sandbox_rst_hang(struct restart_handler *rst)
 
 static void sandbox_rst_reexec(struct restart_handler *rst)
 {
-	u8 reason = RESET_RST;
 	struct sandbox_power *power = container_of(rst, struct sandbox_power, rst_reexec);
 
-	if (!IS_ERR(power->reset_source_cell))
-		WARN_ON(nvmem_cell_write(power->reset_source_cell, &reason, 1) <= 0);
+	sandbox_save_reset_source(power->reset_source_cell, RESET_RST);
 
 	linux_reexec();
 }
@@ -69,7 +68,10 @@ static int sandbox_power_probe(struct device *dev)
 	power->reset_source_cell = of_nvmem_cell_get(dev->of_node,
 						     "reset-source");
 	if (IS_ERR(power->reset_source_cell)) {
-		dev_warn(dev, "No reset source info available: %pe\n", power->reset_source_cell);
+		if (PTR_ERR(power->reset_source_cell) != -EPROBE_DEFER)
+			dev_warn(dev, "No reset source info available: %pe\n",
+				 power->reset_source_cell);
+		power->reset_source_cell = NULL;
 		return 0;
 	}
 
-- 
2.38.4