[PATCH v6 02/23] mfd: max77686: Add power management support

Javier Martinez Canillas
2014-07-04T09:55:01Z

The driver doesn't have PM operations defined so add a suspend
and resume function handlers to allow the PMIC IRQ to wakeup
the system when it is put into a sleep state.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
---
drivers/mfd/max77686.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)

diff --git a/drivers/mfd/max77686.c b/drivers/mfd/max77686.c
index 3cb41d0..a38e9ee 100644
--- a/drivers/mfd/max77686.c
+++ b/drivers/mfd/max77686.c
@@ -240,10 +240,50 @@ static const struct i2c_device_id max77686_i2c_id[] = {
};
MODULE_DEVICE_TABLE(i2c, max77686_i2c_id);

+#ifdef CONFIG_PM_SLEEP
+static int max77686_suspend(struct device *dev)
+{
+ struct i2c_client *i2c = container_of(dev, struct i2c_client, dev);
+ struct max77686_dev *max77686 = i2c_get_clientdata(i2c);
+
+ if (device_may_wakeup(dev))
+ enable_irq_wake(max77686->irq);
+
+ /*
+ * IRQ must be disabled during suspend because if it happens
+ * while suspended it will be handled before resuming I2C.
+ *
+ * When device is woken up from suspend (e.g. by RTC wake alarm),
+ * an interrupt occurs before resuming I2C bus controller.
+ * Interrupt handler tries to read registers but this read
+ * will fail because I2C is still suspended.
+ */
+ disable_irq(max77686->irq);
+
+ return 0;
+}
+
+static int max77686_resume(struct device *dev)
+{
+ struct i2c_client *i2c = container_of(dev, struct i2c_client, dev);
+ struct max77686_dev *max77686 = i2c_get_clientdata(i2c);
+
+ if (device_may_wakeup(dev))
+ disable_irq_wake(max77686->irq);
+
+ enable_irq(max77686->irq);
+
+ return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(max77686_pm, max77686_suspend, max77686_resume);
+
static struct i2c_driver max77686_i2c_driver = {
.driver = {
.name = "max77686",
.owner = THIS_MODULE,
+ .pm = &max77686_pm,
.of_match_table = of_match_ptr(max77686_pmic_dt_match),
},
.probe = max77686_i2c_probe,
--
2.0.0.rc2