regulator: When constraining modes fall back to higher power modes
If a mode requested by a consumer is not allowed by constraints
automatically fall back to a higher power mode if possible. This
ensures that consumers get at least the output they requested while
allowing machine drivers to transparently limit lower power modes
if required.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 0fae51c..7104404a 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -197,9 +197,9 @@
}
/* operating mode constraint check */
-static int regulator_check_mode(struct regulator_dev *rdev, int mode)
+static int regulator_mode_constrain(struct regulator_dev *rdev, int *mode)
{
- switch (mode) {
+ switch (*mode) {
case REGULATOR_MODE_FAST:
case REGULATOR_MODE_NORMAL:
case REGULATOR_MODE_IDLE:
@@ -217,11 +217,17 @@
rdev_err(rdev, "operation not allowed\n");
return -EPERM;
}
- if (!(rdev->constraints->valid_modes_mask & mode)) {
- rdev_err(rdev, "invalid mode %x\n", mode);
- return -EINVAL;
+
+ /* The modes are bitmasks, the most power hungry modes having
+ * the lowest values. If the requested mode isn't supported
+ * try higher modes. */
+ while (*mode) {
+ if (rdev->constraints->valid_modes_mask & *mode)
+ return 0;
+ *mode /= 2;
}
- return 0;
+
+ return -EINVAL;
}
/* dynamic regulator mode switching constraint check */
@@ -612,7 +618,7 @@
output_uV, current_uA);
/* check the new mode is allowed */
- err = regulator_check_mode(rdev, mode);
+ err = regulator_mode_constrain(rdev, &mode);
if (err == 0)
rdev->desc->ops->set_mode(rdev, mode);
}
@@ -2005,7 +2011,7 @@
}
/* constraints check */
- ret = regulator_check_mode(rdev, mode);
+ ret = regulator_mode_constrain(rdev, mode);
if (ret < 0)
goto out;
@@ -2116,7 +2122,7 @@
mode = rdev->desc->ops->get_optimum_mode(rdev,
input_uV, output_uV,
total_uA_load);
- ret = regulator_check_mode(rdev, mode);
+ ret = regulator_mode_constrain(rdev, &mode);
if (ret < 0) {
rdev_err(rdev, "failed to get optimum mode @ %d uA %d -> %d uV\n",
total_uA_load, input_uV, output_uV);