[PATCH v5 13/48] mfd: max8907: Register with kernel power-off handler

Guenter Roeck
2014-11-06T17:02:12Z

directly. Register with low priority 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@linaro.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v5:
- Rebase to v3.18-rc3
v4:
- Do not use notifiers but internal functions and data structures to manage
the list of power-off handlers. Drop unused parameters from callbacks, and
make the power-off function type void
v3:
- Replace poweroff in all newly introduced variables and in text
with power_off or power-off as appropriate
- Replace POWEROFF_PRIORITY_xxx with POWER_OFF_PRIORITY_xxx
v2:
- Use define to specify poweroff handler priority
- Use dev_warn instead of dev_err

drivers/mfd/max8907.c | 21 +++++++++++++++------
include/linux/mfd/max8907.h | 1 +
2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/mfd/max8907.c b/drivers/mfd/max8907.c
index 232749c..84f8afd 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>

@@ -177,10 +178,12 @@ 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 void max8907_power_off(struct power_off_handler_block *this)
{
- regmap_update_bits(max8907_pm_off->regmap_gen, MAX8907_REG_RESET_CNFG,
+ struct max8907 *max8907 = container_of(this, struct max8907,
+ power_off_hb);
+
+ regmap_update_bits(max8907->regmap_gen, MAX8907_REG_RESET_CNFG,
MAX8907_MASK_POWER_OFF, MAX8907_MASK_POWER_OFF);
}

@@ -267,9 +270,13 @@ 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->power_off_hb.handler = max8907_power_off;
+ max8907->power_off_hb.priority = POWER_OFF_PRIORITY_LOW;
+ ret = register_power_off_handler(&max8907->power_off_hb);
+ if (ret)
+ dev_warn(&i2c->dev,
+ "Failed to register power-off handler");
}

return 0;
@@ -293,6 +300,8 @@ static int max8907_i2c_remove(struct i2c_client *i2c)
{
struct max8907 *max8907 = i2c_get_clientdata(i2c);

+ unregister_power_off_handler(&max8907->power_off_hb);
+
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..18a4c68 100644
--- a/include/linux/mfd/max8907.h
+++ b/include/linux/mfd/max8907.h
@@ -247,6 +247,7 @@ 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 power_off_handler_block power_off_hb;
};

#endif
--
1.9.1