diff options
| -rw-r--r-- | Documentation/devicetree/bindings/regulator/regulator.txt | 5 | ||||
| -rw-r--r-- | drivers/regulator/core.c | 76 | ||||
| -rw-r--r-- | drivers/regulator/of_regulator.c | 6 | ||||
| -rw-r--r-- | include/linux/regulator/machine.h | 2 |
4 files changed, 83 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt index 2bd8f0978765..e2c7f1e7251a 100644 --- a/Documentation/devicetree/bindings/regulator/regulator.txt +++ b/Documentation/devicetree/bindings/regulator/regulator.txt @@ -14,6 +14,11 @@ Optional properties: - regulator-ramp-delay: ramp delay for regulator(in uV/uS) For hardwares which support disabling ramp rate, it should be explicitly intialised to zero (regulator-ramp-delay = <0>) for disabling ramp delay. +- regulator-enable-ramp-delay: The time taken, in microseconds, for the supply + rail to reach the target voltage, plus/minus whatever tolerance the board + design requires. This property describes the total system ramp time + required due to the combination of internal ramping of the regulator itself, + and board design issues such as trace capacitance and load on the supply. Deprecated properties: - regulator-compatible: If a regulator chip contains multiple diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 16427de56ce8..916cadf45279 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -919,6 +919,36 @@ static int machine_constraints_voltage(struct regulator_dev *rdev, return 0; } +static int machine_constraints_current(struct regulator_dev *rdev, + struct regulation_constraints *constraints) +{ + struct regulator_ops *ops = rdev->desc->ops; + int ret; + + if (!constraints->min_uA && !constraints->max_uA) + return 0; + + if (constraints->min_uA > constraints->max_uA) { + rdev_err(rdev, "Invalid current constraints\n"); + return -EINVAL; + } + + if (!ops->set_current_limit || !ops->get_current_limit) { + rdev_warn(rdev, "Operation of current configuration missing\n"); + return 0; + } + + /* Set regulator current in constraints range */ + ret = ops->set_current_limit(rdev, constraints->min_uA, + constraints->max_uA); + if (ret < 0) { + rdev_err(rdev, "Failed to set current constraint, %d\n", ret); + return ret; + } + + return 0; +} + /** * set_machine_constraints - sets regulator constraints * @rdev: regulator source @@ -949,6 +979,10 @@ static int set_machine_constraints(struct regulator_dev *rdev, if (ret != 0) goto out; + ret = machine_constraints_current(rdev, rdev->constraints); + if (ret != 0) + goto out; + /* do we need to setup our suspend state */ if (rdev->constraints->initial_state) { ret = suspend_prepare(rdev, rdev->constraints->initial_state); @@ -1182,6 +1216,8 @@ overflow_err: static int _regulator_get_enable_time(struct regulator_dev *rdev) { + if (rdev->constraints && rdev->constraints->enable_time) + return rdev->constraints->enable_time; if (!rdev->desc->ops->enable_time) return rdev->desc->enable_time; return rdev->desc->ops->enable_time(rdev); @@ -1276,7 +1312,7 @@ static struct regulator *_regulator_get(struct device *dev, const char *id, if (id == NULL) { pr_err("get() with no identifier\n"); - return regulator; + return ERR_PTR(-EINVAL); } if (dev) @@ -1733,11 +1769,39 @@ static int _regulator_do_enable(struct regulator_dev *rdev) * together. */ trace_regulator_enable_delay(rdev_get_name(rdev)); - if (delay >= 1000) { - mdelay(delay / 1000); - udelay(delay % 1000); - } else if (delay) { - udelay(delay); + /* + * Delay for the requested amount of time as per the guidelines in: + * + * Documentation/timers/timers-howto.txt + * + * The assumption here is that regulators will never be enabled in + * atomic context and therefore sleeping functions can be used. + */ + if (delay) { + unsigned int ms = delay / 1000; + unsigned int us = delay % 1000; + + if (ms > 0) { + /* + * For small enough values, handle super-millisecond + * delays in the usleep_range() call below. + */ + if (ms < 20) + us += ms * 1000; + else + msleep(ms); + } + + /* + * Give the scheduler some room to coalesce with any other + * wakeup sources. For delays shorter than 10 us, don't even + * bother setting up high-resolution timers and just busy- + * loop. + */ + if (us >= 10) + usleep_range(us, us + 100); + else + udelay(us); } trace_regulator_enable_complete(rdev_get_name(rdev)); diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index 7827384680d6..ea4f36f2cbe2 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -23,6 +23,8 @@ static void of_get_regulation_constraints(struct device_node *np, const __be32 *min_uA, *max_uA, *ramp_delay; struct property *prop; struct regulation_constraints *constraints = &(*init_data)->constraints; + int ret; + u32 pval; constraints->name = of_get_property(np, "regulator-name", NULL); @@ -73,6 +75,10 @@ static void of_get_regulation_constraints(struct device_node *np, else constraints->ramp_disable = true; } + + ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval); + if (!ret) + constraints->enable_time = pval; } /** diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h index 999b20ce06cf..8108751acb86 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -95,6 +95,7 @@ struct regulator_state { * @initial_state: Suspend state to set by default. * @initial_mode: Mode to set at startup. * @ramp_delay: Time to settle down after voltage change (unit: uV/us) + * @enable_time: Turn-on time of the rails (unit: microseconds) */ struct regulation_constraints { @@ -129,6 +130,7 @@ struct regulation_constraints { unsigned int initial_mode; unsigned int ramp_delay; + unsigned int enable_time; /* constraint flags */ unsigned always_on:1; /* regulator never off when system is on */ |