[PATCH v2 0/2] Warm reset support for pm8941-pwrkey

It adds warm reset support for pm8941-pwrkey driver.

Changes for v2:
- Export symbol 'reboot_mode' to fix the build error with pm8941-pwrkey
  being module.  (Thanks Luca Weiss for reporting)

Shawn Guo (2):
  reboot: Export symbol 'reboot_mode'
  Input: pm8941-pwrkey - Respect reboot_mode for warm reset

 drivers/input/misc/pm8941-pwrkey.c | 6 +++++-
 kernel/reboot.c                    | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

-- 
2.17.1

Some drivers like Qualcomm pm8941-pwrkey need to access 'reboot_mode'
for triggering reboot between cold and warm mode.  Export the symbol, so
that drivers built as module can still access the symbol.

Signed-off-by: Shawn Guo <redacted>
---
 kernel/reboot.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/reboot.c b/kernel/reboot.c
index a6ad5eb2fa73..31bf2611ee12 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c

@@ -32,6 +32,7 @@ EXPORT_SYMBOL(cad_pid);
 #define DEFAULT_REBOOT_MODE
 #endif
 enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE;
+EXPORT_SYMBOL_GPL(reboot_mode);
 enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED;
 
 /*

-- 
2.17.1

On some devices, e.g. Sony Xperia M4 Aqua, warm reset is used to reboot
device into bootloader and recovery mode.  Instead of always doing hard
reset, add a check on reboot_mode for possible warm reset.

Signed-off-by: Shawn Guo <redacted>
---
 drivers/input/misc/pm8941-pwrkey.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
index cf8104454e74..9b14d6eb1918 100644
--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c

@@ -27,6 +27,7 @@
 #define PON_PS_HOLD_RST_CTL2		0x5b
 #define  PON_PS_HOLD_ENABLE		BIT(7)
 #define  PON_PS_HOLD_TYPE_MASK		0x0f
+#define  PON_PS_HOLD_TYPE_WARM_RESET	1
 #define  PON_PS_HOLD_TYPE_SHUTDOWN	4
 #define  PON_PS_HOLD_TYPE_HARD_RESET	7
 

@@ -93,7 +94,10 @@ static int pm8941_reboot_notify(struct notifier_block *nb,
 		break;
 	case SYS_RESTART:
 	default:
-		reset_type = PON_PS_HOLD_TYPE_HARD_RESET;
+		if (reboot_mode == REBOOT_WARM)
+			reset_type = PON_PS_HOLD_TYPE_WARM_RESET;
+		else
+			reset_type = PON_PS_HOLD_TYPE_HARD_RESET;
 		break;
 	}
 

-- 
2.17.1

Hi Shawn,

On Mittwoch, 14. Juli 2021 11:58:49 CEST Shawn Guo wrote:

On some devices, e.g. Sony Xperia M4 Aqua, warm reset is used to reboot
device into bootloader and recovery mode.  Instead of always doing hard
reset, add a check on reboot_mode for possible warm reset.

Signed-off-by: Shawn Guo <redacted>

Tested-by: Luca Weiss <redacted>

Rebooting into bootloader works on fairphone-fp2 with these commands now:

$ echo warm > /sys/kernel/reboot/mode
$ reboot-mode bootloader

reboot-mode is this small utility:
https://gitlab.com/postmarketOS/reboot-mode/-/blob/master/reboot-mode.c

Regards
Luca

On Wed, Jul 14, 2021 at 05:58:47PM +0800, Shawn Guo wrote:

It adds warm reset support for pm8941-pwrkey driver.

Changes for v2:
- Export symbol 'reboot_mode' to fix the build error with pm8941-pwrkey
  being module.  (Thanks Luca Weiss for reporting)

Shawn Guo (2):
  reboot: Export symbol 'reboot_mode'
  Input: pm8941-pwrkey - Respect reboot_mode for warm reset

 drivers/input/misc/pm8941-pwrkey.c | 6 +++++-
 kernel/reboot.c                    | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

Hi Dmitry,

Any comments on these patches?

Shawn

On Wed, Jul 14, 2021 at 05:58:48PM +0800, Shawn Guo wrote:

Some drivers like Qualcomm pm8941-pwrkey need to access 'reboot_mode'
for triggering reboot between cold and warm mode.  Export the symbol, so
that drivers built as module can still access the symbol.

Signed-off-by: Shawn Guo <redacted>

Applied, thank you.

-- 
Dmitry

On Wed, Jul 14, 2021 at 05:58:49PM +0800, Shawn Guo wrote:

On some devices, e.g. Sony Xperia M4 Aqua, warm reset is used to reboot
device into bootloader and recovery mode.  Instead of always doing hard
reset, add a check on reboot_mode for possible warm reset.

Signed-off-by: Shawn Guo <redacted>

Applied, thank you.

-- 
Dmitry

On Tue, Aug 24, 2021 at 11:00:59AM +0800, Shawn Guo wrote:

On Wed, Jul 14, 2021 at 05:58:47PM +0800, Shawn Guo wrote:

quoted

It adds warm reset support for pm8941-pwrkey driver.

Changes for v2:
- Export symbol 'reboot_mode' to fix the build error with pm8941-pwrkey
  being module.  (Thanks Luca Weiss for reporting)

Shawn Guo (2):
  reboot: Export symbol 'reboot_mode'
  Input: pm8941-pwrkey - Respect reboot_mode for warm reset

 drivers/input/misc/pm8941-pwrkey.c | 6 +++++-
 kernel/reboot.c                    | 1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

Hi Dmitry,

Any comments on these patches?

Sorry, I was waiting to see if there would be objections to exporting
reboot_mode symbol. Both are applied now.

Thanks.

-- 
Dmitry