[PATCH 13/44] mfd: max8907: Register with kernel poweroff handler

Guenter Roeck
2014-10-07T05:28:15Z

Register with kernel poweroff handler instead of setting pm_power_off
directly. Register with a low priority value of 64 to reflect that
the original code only sets pm_power_off if it was not already set.

Note that this patch fixes a problem on driver unload as side effect:
The old code did not restore or clean up pm_power_off on remove,
meaning the pointer was left in an undefined state.

Cc: Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Samuel Ortiz <sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
---
drivers/mfd/max8907.c | 24 ++++++++++++++++++------
include/linux/mfd/max8907.h | 2 ++
2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/mfd/max8907.c b/drivers/mfd/max8907.c
index 232749c..b8cddc1 100644
--- a/drivers/mfd/max8907.c
+++ b/drivers/mfd/max8907.c
@@ -19,6 +19,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/pm.h>
#include <linux/regmap.h>
#include <linux/slab.h>

@@ -177,11 +178,16 @@ 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 notifier_block *this, unsigned long unused1,
+ void *unused2)
{
- regmap_update_bits(max8907_pm_off->regmap_gen, MAX8907_REG_RESET_CNFG,
+ struct max8907 *max8907 = container_of(this, struct max8907,
+ poweroff_nb);
+
+ regmap_update_bits(max8907->regmap_gen, MAX8907_REG_RESET_CNFG,
MAX8907_MASK_POWER_OFF, MAX8907_MASK_POWER_OFF);
+
+ return NOTIFY_DONE;
}

static int max8907_i2c_probe(struct i2c_client *i2c,
@@ -267,9 +273,13 @@ static int max8907_i2c_probe(struct i2c_client *i2c,
goto err_add_devices;
}

- if (pm_off && !pm_power_off) {
- max8907_pm_off = max8907;
- pm_power_off = max8907_power_off;
+ if (pm_off) {
+ max8907->poweroff_nb.notifier_call = max8907_power_off;
+ max8907->poweroff_nb.priority = 64;
+ ret = register_poweroff_handler(&max8907->poweroff_nb);
+ if (ret)
+ dev_err(&i2c->dev,
+ "Failed to register poweroff handler");
}

return 0;
@@ -293,6 +303,8 @@ static int max8907_i2c_remove(struct i2c_client *i2c)
{
struct max8907 *max8907 = i2c_get_clientdata(i2c);

+ unregister_poweroff_handler(&max8907->poweroff_nb);
+
mfd_remove_devices(max8907->dev);

regmap_del_irq_chip(max8907->i2c_gen->irq, max8907->irqc_rtc);
diff --git a/include/linux/mfd/max8907.h b/include/linux/mfd/max8907.h
index b06f7a6..016428e 100644
--- a/include/linux/mfd/max8907.h
+++ b/include/linux/mfd/max8907.h
@@ -13,6 +13,7 @@
#define __LINUX_MFD_MAX8907_H

#include <linux/mutex.h>
+#include <linux/notifier.h>
#include <linux/pm.h>

#define MAX8907_GEN_I2C_ADDR (0x78 >> 1)
@@ -247,6 +248,7 @@ struct max8907 {
struct regmap_irq_chip_data *irqc_chg;
struct regmap_irq_chip_data *irqc_on_off;
struct regmap_irq_chip_data *irqc_rtc;
+ struct notifier_block poweroff_nb;
};

#endif
--
1.9.1