regulator: core: Support setting suspend_[mode|voltage] if set_suspend_[en|dis]able...

In current implementation, to support set_suspend_voltage and set_suspend_mode
the regulator code needs the regulator driver to implement both
set_suspend_enable and set_suspend_disable callbacks.

This patch removes this limitation. In the case set_suspend_enable and/or
set_suspend_disable are NULL, the regulator code assumes we don't need to
do any thing to enable/disable regulator when system is suspended and
then will continue to handle set_suspend_mode and set_suspend_voltage.

Currently the regulator core creates suspend state related sysfs entries only
if both set_suspend_enable and set_suspend_disable callbacks are not NULL.
A side-effect of this change is that the regulator core will create suspend
state related sysfs entries unconditionally now.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 713981b52f2a10e09f74feb453f178624b96e935..5c0c975e5ac2f5a0bb177abca8e39b4d06195130 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -673,17 +673,14 @@ static int suspend_set_state(struct regulator_dev *rdev,
        struct regulator_state *rstate)
 {
        int ret = 0;
-       bool can_set_state;
-
-       can_set_state = rdev->desc->ops->set_suspend_enable &&
-               rdev->desc->ops->set_suspend_disable;
 
        /* If we have no suspend mode configration don't set anything;
-        * only warn if the driver actually makes the suspend mode
-        * configurable.
+        * only warn if the driver implements set_suspend_voltage or
+        * set_suspend_mode callback.
         */
        if (!rstate->enabled && !rstate->disabled) {
-               if (can_set_state)
+               if (rdev->desc->ops->set_suspend_voltage ||
+                   rdev->desc->ops->set_suspend_mode)
                        rdev_warn(rdev, "No configuration\n");
                return 0;
        }
@@ -693,15 +690,13 @@ static int suspend_set_state(struct regulator_dev *rdev,
                return -EINVAL;
        }
 
-       if (!can_set_state) {
-               rdev_err(rdev, "no way to set suspend state\n");
-               return -EINVAL;
-       }
-
-       if (rstate->enabled)
+       if (rstate->enabled && rdev->desc->ops->set_suspend_enable)
                ret = rdev->desc->ops->set_suspend_enable(rdev);
-       else
+       else if (rstate->disabled && rdev->desc->ops->set_suspend_disable)
                ret = rdev->desc->ops->set_suspend_disable(rdev);
+       else /* OK if set_suspend_enable or set_suspend_disable is NULL */
+               ret = 0;
+
        if (ret < 0) {
                rdev_err(rdev, "failed to enabled/disable\n");
                return ret;
@@ -2776,10 +2771,6 @@ static int add_regulator_attributes(struct regulator_dev *rdev)
                        return status;
        }
 
-       /* suspend mode constraints need multiple supporting methods */
-       if (!(ops->set_suspend_enable && ops->set_suspend_disable))
-               return status;
-
        status = device_create_file(dev, &dev_attr_suspend_standby_state);
        if (status < 0)
                return status;