[PATCH v4 3/6] iio: imu: kmx61: Add PM runtime support

Daniel Baluta
2014-12-03T13:36:10Z

By default both sensors are ACTIVE, in this way the driver
will work even if CONFIG_PM_RUNTIME is not selected.

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
---
drivers/iio/imu/kmx61.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 112 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/imu/kmx61.c b/drivers/iio/imu/kmx61.c
index 893f7c8..7536043 100644
--- a/drivers/iio/imu/kmx61.c
+++ b/drivers/iio/imu/kmx61.c
@@ -15,6 +15,8 @@
#include <linux/i2c.h>
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

@@ -69,6 +71,8 @@
#define KMX61_ACC_ODR_MASK 0x0F
#define KMX61_MAG_ODR_MASK 0xF0

+#define KMX61_SLEEP_DELAY_MS 2000
+
#define KMX61_CHIP_ID 0x12

/* KMX61 devices */
@@ -85,6 +89,10 @@ struct kmx61_data {
bool acc_stby;
bool mag_stby;

+ /* power state */
+ bool acc_ps;
+ bool mag_ps;
+
/* config bits */
u8 range;
u8 odr_bits;
@@ -457,6 +465,58 @@ static int kmx61_chip_init(struct kmx61_data *data)
return 0;
}

+/**
+ * kmx61_set_power_state() - set power state for kmx61 @device
+ * @data - kmx61 device private pointer
+ * @on - power state to be set for @device
+ * @device - bitmask indicating device for which @on state needs to be set
+ *
+ * Notice that when ACC power state needs to be set to ON and MAG is in
+ * OPERATION then we know that kmx61_runtime_resume was already called
+ * so we must set ACC OPERATION mode here. The same happens when MAG power
+ * state needs to be set to ON and ACC is in OPERATION.
+ */
+static int kmx61_set_power_state(struct kmx61_data *data, bool on, u8 device)
+{
+#ifdef CONFIG_PM_RUNTIME
+ int ret;
+
+ if (device & KMX61_ACC) {
+ if (on && !data->acc_ps && !data->mag_stby) {
+ ret = kmx61_set_mode(data, 0, KMX61_ACC, true);
+ if (ret < 0)
+ return ret;
+ }
+ data->acc_ps = on;
+ }
+ if (device & KMX61_MAG) {
+ if (on && !data->mag_ps && !data->acc_stby) {
+ ret = kmx61_set_mode(data, 0, KMX61_MAG, true);
+ if (ret < 0)
+ return ret;
+ }
+ data->mag_ps = on;
+ }
+
+ if (on) {
+ ret = pm_runtime_get_sync(&data->client->dev);
+ } else {
+ pm_runtime_mark_last_busy(&data->client->dev);
+ ret = pm_runtime_put_autosuspend(&data->client->dev);
+ }
+ if (ret < 0) {
+ dev_err(&data->client->dev,
+ "Failed: kmx61_set_power_state for %d, ret %d\n",
+ on, ret);
+ if (on)
+ pm_runtime_put_noidle(&data->client->dev);
+
+ return ret;
+ }
+#endif
+ return 0;
+}
+
static int kmx61_read_measurement(struct kmx61_data *data, u8 base, u8 offset)
{
int ret;
@@ -491,13 +551,16 @@ static int kmx61_read_raw(struct iio_dev *indio_dev,
}
mutex_lock(&data->lock);

+ kmx61_set_power_state(data, true, chan->address);
ret = kmx61_read_measurement(data, base_reg, chan->scan_index);
if (ret < 0) {
+ kmx61_set_power_state(data, false, chan->address);
mutex_unlock(&data->lock);
return ret;
}
*val = sign_extend32(ret >> chan->scan_type.shift,
chan->scan_type.realbits - 1);
+ kmx61_set_power_state(data, false, chan->address);

mutex_unlock(&data->lock);
return IIO_VAL_INT;
@@ -693,12 +756,22 @@ static int kmx61_probe(struct i2c_client *client,
ret = iio_device_register(data->mag_indio_dev);
if (ret < 0) {
dev_err(&client->dev, "Failed to register mag iio device\n");
- goto err_iio_unregister;
+ goto err_iio_unregister_acc;
}

+ ret = pm_runtime_set_active(&client->dev);
+ if (ret < 0)
+ goto err_iio_unregister_mag;
+
+ pm_runtime_enable(&client->dev);
+ pm_runtime_set_autosuspend_delay(&client->dev, KMX61_SLEEP_DELAY_MS);
+ pm_runtime_use_autosuspend(&client->dev);
+
return 0;

-err_iio_unregister:
+err_iio_unregister_mag:
+ iio_device_unregister(data->mag_indio_dev);
+err_iio_unregister_acc:
iio_device_unregister(data->acc_indio_dev);
err_chip_uninit:
kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
@@ -709,6 +782,10 @@ static int kmx61_remove(struct i2c_client *client)
{
struct kmx61_data *data = i2c_get_clientdata(client);

+ pm_runtime_disable(&client->dev);
+ pm_runtime_set_suspended(&client->dev);
+ pm_runtime_put_noidle(&client->dev);
+
iio_device_unregister(data->acc_indio_dev);
iio_device_unregister(data->mag_indio_dev);

@@ -719,6 +796,38 @@ static int kmx61_remove(struct i2c_client *client)
return 0;
}

+
+#ifdef CONFIG_PM_RUNTIME
+static int kmx61_runtime_suspend(struct device *dev)
+{
+ struct kmx61_data *data = i2c_get_clientdata(to_i2c_client(dev));
+ int ret;
+
+ mutex_lock(&data->lock);
+ ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static int kmx61_runtime_resume(struct device *dev)
+{
+ struct kmx61_data *data = i2c_get_clientdata(to_i2c_client(dev));
+ u8 stby = 0;
+
+ if (!data->acc_ps)
+ stby |= KMX61_ACC_STBY_BIT;
+ if (!data->mag_ps)
+ stby |= KMX61_MAG_STBY_BIT;
+
+ return kmx61_set_mode(data, stby, KMX61_ACC | KMX61_MAG, true);
+}
+#endif
+
+static const struct dev_pm_ops kmx61_pm_ops = {
+ SET_RUNTIME_PM_OPS(kmx61_runtime_suspend, kmx61_runtime_resume, NULL)
+};
+
static const struct acpi_device_id kmx61_acpi_match[] = {
{"KMX61021", 0},
{}
@@ -737,6 +846,7 @@ static struct i2c_driver kmx61_driver = {
.driver = {
.name = KMX61_DRV_NAME,
.acpi_match_table = ACPI_PTR(kmx61_acpi_match),
+ .pm = &kmx61_pm_ops,
},
.probe = kmx61_probe,
.remove = kmx61_remove,
--
1.9.1