[PATCH 01/12] hwmon: lis3: pm_runtime support

Samu Onkalo
2010-10-22T11:57:23Z

Add pm_runtime support to lis3 core driver.
Add pm_runtime support to lis3 i2c driver.

spi and hp_accel drivers are not yet supported. Old always
on functionality remains for those.

For sysfs there is 5 second delay before turning off the
chip to avoid long ramp up delay.

Signed-off-by: Samu Onkalo <samu.p.onkalo-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
---
drivers/hwmon/lis3lv02d.c | 60 +++++++++++++++++++++++++++++++++++++++++
drivers/hwmon/lis3lv02d.h | 1 +
drivers/hwmon/lis3lv02d_i2c.c | 54 ++++++++++++++++++++++++++++---------
3 files changed, 102 insertions(+), 13 deletions(-)

diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c
index fc591ae..412ddc3 100644
--- a/drivers/hwmon/lis3lv02d.c
+++ b/drivers/hwmon/lis3lv02d.c
@@ -34,6 +34,7 @@
#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
+#include <linux/pm_runtime.h>
#include <asm/atomic.h>
#include "lis3lv02d.h"

@@ -43,6 +44,9 @@
#define MDPS_POLL_INTERVAL 50
#define MDPS_POLL_MIN 0
#define MDPS_POLL_MAX 2000
+
+#define LIS3_SYSFS_POWERDOWN_DELAY 5000 /* In milliseconds */
+
/*
* The sensor can also generate interrupts (DRDY) but it's pretty pointless
* because they are generated even if the data do not change. So it's better
@@ -262,6 +266,18 @@ static void lis3lv02d_joystick_poll(struct input_polled_dev *pidev)
mutex_unlock(&lis3_dev.mutex);
}

+static void lis3lv02d_joystick_open(struct input_polled_dev *pidev)
+{
+ if (lis3_dev.pm_dev)
+ pm_runtime_get_sync(lis3_dev.pm_dev);
+}
+
+static void lis3lv02d_joystick_close(struct input_polled_dev *pidev)
+{
+ if (lis3_dev.pm_dev)
+ pm_runtime_put(lis3_dev.pm_dev);
+}
+
static irqreturn_t lis302dl_interrupt(int irq, void *dummy)
{
if (!test_bit(0, &lis3_dev.misc_opened))
@@ -356,6 +372,9 @@ static int lis3lv02d_misc_open(struct inode *inode, struct file *file)
if (test_and_set_bit(0, &lis3_dev.misc_opened))
return -EBUSY; /* already open */

+ if (lis3_dev.pm_dev)
+ pm_runtime_get_sync(lis3_dev.pm_dev);
+
atomic_set(&lis3_dev.count, 0);
return 0;
}
@@ -364,6 +383,8 @@ static int lis3lv02d_misc_release(struct inode *inode, struct file *file)
{
fasync_helper(-1, file, 0, &lis3_dev.async_queue);
clear_bit(0, &lis3_dev.misc_opened); /* release the device */
+ if (lis3_dev.pm_dev)
+ pm_runtime_put(lis3_dev.pm_dev);
return 0;
}

@@ -460,6 +481,8 @@ int lis3lv02d_joystick_enable(void)
return -ENOMEM;

lis3_dev.idev->poll = lis3lv02d_joystick_poll;
+ lis3_dev.idev->open = lis3lv02d_joystick_open;
+ lis3_dev.idev->close = lis3lv02d_joystick_close;
lis3_dev.idev->poll_interval = MDPS_POLL_INTERVAL;
lis3_dev.idev->poll_interval_min = MDPS_POLL_MIN;
lis3_dev.idev->poll_interval_max = MDPS_POLL_MAX;
@@ -512,12 +535,30 @@ void lis3lv02d_joystick_disable(void)
EXPORT_SYMBOL_GPL(lis3lv02d_joystick_disable);

/* Sysfs stuff */
+static void lis3lv02d_sysfs_poweron(struct lis3lv02d *lis3)
+{
+ /*
+ * SYSFS functions are fast visitors so put-call
+ * immediately after the get-call. However, keep
+ * chip running for a while and schedule delayed
+ * suspend. This way periodic sysfs calls doesn't
+ * suffer from relatively long power up time.
+ */
+
+ if (lis3->pm_dev) {
+ pm_runtime_get_sync(lis3->pm_dev);
+ pm_runtime_put_noidle(lis3->pm_dev);
+ pm_schedule_suspend(lis3->pm_dev, LIS3_SYSFS_POWERDOWN_DELAY);
+ }
+}
+
static ssize_t lis3lv02d_selftest_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int result;
s16 values[3];

+ lis3lv02d_sysfs_poweron(&lis3_dev);
result = lis3lv02d_selftest(&lis3_dev, values);
return sprintf(buf, "%s %d %d %d\n", result == 0 ? "OK" : "FAIL",
values[0], values[1], values[2]);
@@ -528,6 +569,7 @@ static ssize_t lis3lv02d_position_show(struct device *dev,
{
int x, y, z;

+ lis3lv02d_sysfs_poweron(&lis3_dev);
mutex_lock(&lis3_dev.mutex);
lis3lv02d_get_xyz(&lis3_dev, &x, &y, &z);
mutex_unlock(&lis3_dev.mutex);
@@ -537,6 +579,7 @@ static ssize_t lis3lv02d_position_show(struct device *dev,
static ssize_t lis3lv02d_rate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
+ lis3lv02d_sysfs_poweron(&lis3_dev);
return sprintf(buf, "%d\n", lis3lv02d_get_odr());
}

@@ -549,6 +592,7 @@ static ssize_t lis3lv02d_rate_set(struct device *dev,
if (strict_strtoul(buf, 0, &rate))
return -EINVAL;

+ lis3lv02d_sysfs_poweron(&lis3_dev);
if (lis3lv02d_set_odr(rate))
return -EINVAL;

@@ -585,6 +629,17 @@ int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
{
sysfs_remove_group(&lis3->pdev->dev.kobj, &lis3lv02d_attribute_group);
platform_device_unregister(lis3->pdev);
+ if (lis3->pm_dev) {
+ /* Barrier after the sysfs remove */
+ pm_runtime_barrier(lis3->pm_dev);
+
+ /* SYSFS may have left chip running. Turn off if necessary */
+ if (!pm_runtime_suspended(lis3->pm_dev))
+ lis3lv02d_poweroff(&lis3_dev);
+
+ pm_runtime_disable(lis3->pm_dev);
+ pm_runtime_set_suspended(lis3->pm_dev);
+ }
return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
@@ -685,6 +740,11 @@ int lis3lv02d_init_device(struct lis3lv02d *dev)
lis3lv02d_add_fs(dev);
lis3lv02d_poweron(dev);

+ if (dev->pm_dev) {
+ pm_runtime_set_active(dev->pm_dev);
+ pm_runtime_enable(dev->pm_dev);
+ }
+
if (lis3lv02d_joystick_enable())
printk(KERN_ERR DRIVER_NAME ": joystick initialization failed\n");

diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h
index 8540913..3e8a208 100644
--- a/drivers/hwmon/lis3lv02d.h
+++ b/drivers/hwmon/lis3lv02d.h
@@ -214,6 +214,7 @@ struct axis_conversion {

struct lis3lv02d {
void *bus_priv; /* used by the bus layer only */
+ struct device *pm_dev; /* for pm_runtime purposes */
int (*init) (struct lis3lv02d *lis3);
int (*write) (struct lis3lv02d *lis3, int reg, u8 val);
int (*read) (struct lis3lv02d *lis3, int reg, u8 *ret);
diff --git a/drivers/hwmon/lis3lv02d_i2c.c b/drivers/hwmon/lis3lv02d_i2c.c
index 8e5933b..6e965d7 100644
--- a/drivers/hwmon/lis3lv02d_i2c.c
+++ b/drivers/hwmon/lis3lv02d_i2c.c
@@ -29,6 +29,7 @@
#include <linux/init.h>
#include <linux/err.h>
#include <linux/i2c.h>
+#include <linux/pm_runtime.h>
#include "lis3lv02d.h"

#define DRV_NAME "lis3lv02d_i2c"
@@ -95,6 +96,7 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
lis3_dev.write = lis3_i2c_write;
lis3_dev.irq = client->irq;
lis3_dev.ac = lis3lv02d_axis_map;
+ lis3_dev.pm_dev = &client->dev;

i2c_set_clientdata(client, &lis3_dev);
ret = lis3lv02d_init_device(&lis3_dev);
@@ -104,21 +106,20 @@ fail:

static int __devexit lis3lv02d_i2c_remove(struct i2c_client *client)
{
- struct lis3lv02d *lis3 = i2c_get_clientdata(client);
struct lis3lv02d_platform_data *pdata = client->dev.platform_data;

if (pdata && pdata->release_resources)
pdata->release_resources();

lis3lv02d_joystick_disable();
- lis3lv02d_poweroff(lis3);

return lis3lv02d_remove_fs(&lis3_dev);
}

#ifdef CONFIG_PM
-static int lis3lv02d_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
+static int lis3lv02d_i2c_suspend(struct device *dev)
{
+ struct i2c_client *client = container_of(dev, struct i2c_client, dev);
struct lis3lv02d *lis3 = i2c_get_clientdata(client);

if (!lis3->pdata || !lis3->pdata->wakeup_flags)
@@ -126,18 +127,21 @@ static int lis3lv02d_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
return 0;
}

-static int lis3lv02d_i2c_resume(struct i2c_client *client)
+static int lis3lv02d_i2c_resume(struct device *dev)
{
+ struct i2c_client *client = container_of(dev, struct i2c_client, dev);
struct lis3lv02d *lis3 = i2c_get_clientdata(client);

- if (!lis3->pdata || !lis3->pdata->wakeup_flags)
+ /*
+ * pm_runtime documentation says that devices should always
+ * be powered on at resume. Pm_runtime turns them off after system
+ * wide resume is complete.
+ */
+ if (!lis3->pdata || !lis3->pdata->wakeup_flags ||
+ pm_runtime_suspended(dev))
lis3lv02d_poweron(lis3);
- return 0;
-}

-static void lis3lv02d_i2c_shutdown(struct i2c_client *client)
-{
- lis3lv02d_i2c_suspend(client, PMSG_SUSPEND);
+ return 0;
}
#else
#define lis3lv02d_i2c_suspend NULL
@@ -145,6 +149,24 @@ static void lis3lv02d_i2c_shutdown(struct i2c_client *client)
#define lis3lv02d_i2c_shutdown NULL
#endif

+static int lis3_i2c_runtime_suspend(struct device *dev)
+{
+ struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+ struct lis3lv02d *lis3 = i2c_get_clientdata(client);
+
+ lis3lv02d_poweroff(lis3);
+ return 0;
+}
+
+static int lis3_i2c_runtime_resume(struct device *dev)
+{
+ struct i2c_client *client = container_of(dev, struct i2c_client, dev);
+ struct lis3lv02d *lis3 = i2c_get_clientdata(client);
+
+ lis3lv02d_poweron(lis3);
+ return 0;
+}
+
static const struct i2c_device_id lis3lv02d_id[] = {
{"lis3lv02d", 0 },
{}
@@ -152,14 +174,20 @@ static const struct i2c_device_id lis3lv02d_id[] = {

MODULE_DEVICE_TABLE(i2c, lis3lv02d_id);

+static const struct dev_pm_ops lis3_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(lis3lv02d_i2c_suspend,
+ lis3lv02d_i2c_resume)
+ SET_RUNTIME_PM_OPS(lis3_i2c_runtime_suspend,
+ lis3_i2c_runtime_resume,
+ NULL)
+};
+
static struct i2c_driver lis3lv02d_i2c_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
+ .pm = &lis3_pm_ops,
},
- .suspend = lis3lv02d_i2c_suspend,
- .shutdown = lis3lv02d_i2c_shutdown,
- .resume = lis3lv02d_i2c_resume,
.probe = lis3lv02d_i2c_probe,
.remove = __devexit_p(lis3lv02d_i2c_remove),
.id_table = lis3lv02d_id,
--
1.6.0.4