linux-kernel - [PATCH] mfd: axp20x: Switch to the sys-off handler API

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Date:   Wed, 28 Dec 2022 10:27:52 -0600
From:   Samuel Holland <samuel@...lland.org>
To:     Chen-Yu Tsai <wens@...e.org>, Lee Jones <lee@...nel.org>
Cc:     Samuel Holland <samuel@...lland.org>, linux-kernel@...r.kernel.org
Subject: [PATCH] mfd: axp20x: Switch to the sys-off handler API

This removes a layer of indirection through pm_power_off() and allows
the PMIC handler to be used as a fallback when firmware power off fails.
This happens on boards like the Clockwork DevTerm R-01 where OpenSBI
does not know how to use the PMIC to power off the board.

Move the check for AXP288 to avoid registering a dummy handler.

Signed-off-by: Samuel Holland <samuel@...lland.org>
---
Note: this patch depends on updating the PSCI driver first[1] to keep
the existing callback priority.

[1]: https://lore.kernel.org/lkml/20221105214841.7828-1-samuel@sholland.org/

 drivers/mfd/axp20x.c | 26 +++++++++++---------------
 1 file changed, 11 insertions(+), 15 deletions(-)

diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
index 47fd700f284f..58f82f1f4b43 100644
--- a/drivers/mfd/axp20x.c
+++ b/drivers/mfd/axp20x.c
@@ -23,7 +23,7 @@
 #include <linux/mfd/core.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
-#include <linux/pm_runtime.h>
+#include <linux/reboot.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 
@@ -825,17 +825,17 @@ static const struct mfd_cell axp813_cells[] = {
 	},
 };
 
-static struct axp20x_dev *axp20x_pm_power_off;
-static void axp20x_power_off(void)
+static int axp20x_power_off(struct sys_off_data *data)
 {
-	if (axp20x_pm_power_off->variant == AXP288_ID)
-		return;
+	struct axp20x_dev *axp20x = data->cb_data;
 
-	regmap_write(axp20x_pm_power_off->regmap, AXP20X_OFF_CTRL,
+	regmap_write(axp20x->regmap, AXP20X_OFF_CTRL,
 		     AXP20X_OFF);
 
 	/* Give capacitors etc. time to drain to avoid kernel panic msg. */
 	mdelay(500);
+
+	return NOTIFY_DONE;
 }
 
 int axp20x_match_device(struct axp20x_dev *axp20x)
@@ -1002,10 +1002,11 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
 		return ret;
 	}
 
-	if (!pm_power_off) {
-		axp20x_pm_power_off = axp20x;
-		pm_power_off = axp20x_power_off;
-	}
+	if (axp20x->variant != AXP288_ID)
+		devm_register_sys_off_handler(axp20x->dev,
+					      SYS_OFF_MODE_POWER_OFF,
+					      SYS_OFF_PRIO_DEFAULT,
+					      axp20x_power_off, axp20x);
 
 	dev_info(axp20x->dev, "AXP20X driver loaded\n");
 
@@ -1015,11 +1016,6 @@ EXPORT_SYMBOL(axp20x_device_probe);
 
 void axp20x_device_remove(struct axp20x_dev *axp20x)
 {
-	if (axp20x == axp20x_pm_power_off) {
-		axp20x_pm_power_off = NULL;
-		pm_power_off = NULL;
-	}
-
 	mfd_remove_devices(axp20x->dev);
 	regmap_del_irq_chip(axp20x->irq, axp20x->regmap_irqc);
 }
-- 
2.37.4