diff options
| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-03-30 01:29:12 +0400 |
|---|---|---|
| committer | Liam Girdwood <lrg@slimlogic.co.uk> | 2011-05-27 13:34:35 +0400 |
| commit | 2c6082341d1896218ca974cc2bb6876e36fcba5c (patch) | |
| tree | f5ca00b3402eb36a0581c4481787ede5a4be5c72 | |
| parent | dc7acbb2518f250050179c8581a972df3b6a24f1 (diff) | |
| download | linux-2c6082341d1896218ca974cc2bb6876e36fcba5c.tar.xz | |
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>
| -rw-r--r-- | drivers/regulator/core.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 0fae51c4845a..7104404a9fa7 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -197,9 +197,9 @@ static int regulator_check_current_limit(struct regulator_dev *rdev, } /* 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 @@ static int regulator_check_mode(struct regulator_dev *rdev, int mode) 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 @@ static void drms_uA_update(struct regulator_dev *rdev) 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 @@ int regulator_set_mode(struct regulator *regulator, unsigned int mode) } /* constraints check */ - ret = regulator_check_mode(rdev, mode); + ret = regulator_mode_constrain(rdev, mode); if (ret < 0) goto out; @@ -2116,7 +2122,7 @@ int regulator_set_optimum_mode(struct regulator *regulator, int uA_load) 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); |