[PATCH v3 4/4] mfd: max8907: Convert to use device managed poweroff handler

[Svyatoslav Ryhel <clamor95@gmail.com>]

Replace the legacy global 'pm_power_off' function pointer assignment with
the devm_register_power_off_handler() helper.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/mfd/max8907.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/mfd/max8907.c b/drivers/mfd/max8907.c
index fab44be7ced57..6d5e6a1556fd5 100644
--- a/drivers/mfd/max8907.c
+++ b/drivers/mfd/max8907.c
@@ -15,6 +15,7 @@
 #include <linux/mfd/max8907.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/reboot.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
@@ -173,11 +174,17 @@ static const struct regmap_irq_chip max8907_rtc_irq_chip = {
 	.num_irqs = ARRAY_SIZE(max8907_rtc_irqs),
 };
 
-static struct max8907 *max8907_pm_off;
-static void max8907_power_off(void)
+static int max8907_power_off(struct sys_off_data *data)
 {
-	regmap_update_bits(max8907_pm_off->regmap_gen, MAX8907_REG_RESET_CNFG,
-			MAX8907_MASK_POWER_OFF, MAX8907_MASK_POWER_OFF);
+	struct max8907 *max8907 = data->cb_data;
+	int ret;
+
+	ret = regmap_update_bits(max8907->regmap_gen, MAX8907_REG_RESET_CNFG,
+				 MAX8907_MASK_POWER_OFF, MAX8907_MASK_POWER_OFF);
+	if (ret)
+		dev_err(max8907->dev, "failed to power off the device!\n");
+
+	return NOTIFY_DONE;
 }
 
 static int max8907_i2c_probe(struct i2c_client *i2c)
@@ -185,8 +192,6 @@ static int max8907_i2c_probe(struct i2c_client *i2c)
 	struct device *dev = &i2c->dev;
 	struct max8907 *max8907;
 	int ret;
-	bool pm_off = of_property_read_bool(dev->of_node,
-					"maxim,system-power-controller");
 
 	max8907 = devm_kzalloc(dev, sizeof(*max8907), GFP_KERNEL);
 	if (!max8907)
@@ -238,9 +243,10 @@ static int max8907_i2c_probe(struct i2c_client *i2c)
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to add MFD devices\n");
 
-	if (pm_off && !pm_power_off) {
-		max8907_pm_off = max8907;
-		pm_power_off = max8907_power_off;
+	if (of_device_is_system_power_controller(dev->of_node)) {
+		ret = devm_register_power_off_handler(dev, max8907_power_off, max8907);
+		if (ret)
+			return dev_err_probe(dev, ret, "failed to register power-off handler\n");
 	}
 
 	return 0;
-- 
2.53.0