From 9a2372fa7a403ba327873d0208a619d781a8a150 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 3 Aug 2009 18:49:57 +0100 Subject: regulator: regulator_enable() permission checking The regulator_enable() code wasn't actually checking that the machine constraints had given permission to enable the regulator. Add code to do that, but only if the regulator is not already on due to something like always_on or being left on at startup since in those cases there's no physical change being introduced and the constraint wouldn't make any sense. Also add matching code for disable(). We need to do less there since either regulator_enable() should have succeeded first or the board setup makes no sense. Signed-off-by: Mark Brown Signed-off-by: Liam Girdwood --- drivers/regulator/core.c | 56 +++++++++++++++++++++++++++++++----------------- 1 file changed, 36 insertions(+), 20 deletions(-) (limited to 'drivers') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 60fcd986ff3f..dbf27bf028c4 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1191,16 +1191,21 @@ void regulator_put(struct regulator *regulator) } EXPORT_SYMBOL_GPL(regulator_put); +static int _regulator_can_change_status(struct regulator_dev *rdev) +{ + if (!rdev->constraints) + return 0; + + if (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_STATUS) + return 1; + else + return 0; +} + /* locks held by regulator_enable() */ static int _regulator_enable(struct regulator_dev *rdev) { - int ret = -EINVAL; - - if (!rdev->constraints) { - printk(KERN_ERR "%s: %s has no constraints\n", - __func__, rdev->desc->name); - return ret; - } + int ret; /* do we need to enable the supply regulator first */ if (rdev->supply) { @@ -1213,24 +1218,34 @@ static int _regulator_enable(struct regulator_dev *rdev) } /* check voltage and requested load before enabling */ - if (rdev->desc->ops->enable) { + if (rdev->constraints && + (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS)) + drms_uA_update(rdev); - if (rdev->constraints && - (rdev->constraints->valid_ops_mask & - REGULATOR_CHANGE_DRMS)) - drms_uA_update(rdev); - - ret = rdev->desc->ops->enable(rdev); - if (ret < 0) { - printk(KERN_ERR "%s: failed to enable %s: %d\n", + if (rdev->use_count == 0) { + /* The regulator may on if it's not switchable or left on */ + ret = _regulator_is_enabled(rdev); + if (ret == -EINVAL || ret == 0) { + if (!_regulator_can_change_status(rdev)) + return -EPERM; + + if (rdev->desc->ops->enable) { + ret = rdev->desc->ops->enable(rdev); + if (ret < 0) + return ret; + } else { + return -EINVAL; + } + } else { + printk(KERN_ERR "%s: is_enabled() failed for %s: %d\n", __func__, rdev->desc->name, ret); return ret; } - rdev->use_count++; - return ret; } - return ret; + rdev->use_count++; + + return 0; } /** @@ -1270,7 +1285,8 @@ static int _regulator_disable(struct regulator_dev *rdev) if (rdev->use_count == 1 && !rdev->constraints->always_on) { /* we are last user */ - if (rdev->desc->ops->disable) { + if (_regulator_can_change_status(rdev) && + rdev->desc->ops->disable) { ret = rdev->desc->ops->disable(rdev); if (ret < 0) { printk(KERN_ERR "%s: failed to disable %s\n", -- cgit v1.2.2