regulator: Allow regulators to register with no init_data

This allows read-only access to the device configuration which may be
useful for diagnostics.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index ca2efca00734b704aa85f8a98191945aecd89a6a..dbdebed660bf35760df1b26abab5bcd560070a9d 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -912,8 +912,12 @@ static int set_machine_constraints(struct regulator_dev *rdev,
        int ret = 0;
        struct regulator_ops *ops = rdev->desc->ops;
 
-       rdev->constraints = kmemdup(constraints, sizeof(*constraints),
-                                   GFP_KERNEL);
+       if (constraints)
+               rdev->constraints = kmemdup(constraints, sizeof(*constraints),
+                                           GFP_KERNEL);
+       else
+               rdev->constraints = kzalloc(sizeof(*constraints),
+                                           GFP_KERNEL);
        if (!rdev->constraints)
                return -ENOMEM;
 
@@ -922,7 +926,7 @@ static int set_machine_constraints(struct regulator_dev *rdev,
                goto out;
 
        /* do we need to setup our suspend state */
-       if (constraints->initial_state) {
+       if (rdev->constraints->initial_state) {
                ret = suspend_prepare(rdev, rdev->constraints->initial_state);
                if (ret < 0) {
                        rdev_err(rdev, "failed to set suspend state\n");
@@ -930,7 +934,7 @@ static int set_machine_constraints(struct regulator_dev *rdev,
                }
        }
 
-       if (constraints->initial_mode) {
+       if (rdev->constraints->initial_mode) {
                if (!ops->set_mode) {
                        rdev_err(rdev, "no set_mode operation\n");
                        ret = -EINVAL;
@@ -2697,6 +2701,7 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
        struct device *dev, const struct regulator_init_data *init_data,
        void *driver_data, struct device_node *of_node)
 {
+       const struct regulation_constraints *constraints = NULL;
        static atomic_t regulator_no = ATOMIC_INIT(0);
        struct regulator_dev *rdev;
        int ret, i;
@@ -2712,9 +2717,6 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
            regulator_desc->type != REGULATOR_CURRENT)
                return ERR_PTR(-EINVAL);
 
-       if (!init_data)
-               return ERR_PTR(-EINVAL);
-
        /* Only one of each should be implemented */
        WARN_ON(regulator_desc->ops->get_voltage &&
                regulator_desc->ops->get_voltage_sel);
@@ -2747,7 +2749,7 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
        INIT_DELAYED_WORK(&rdev->disable_work, regulator_disable_work);
 
        /* preform any regulator specific init */
-       if (init_data->regulator_init) {
+       if (init_data && init_data->regulator_init) {
                ret = init_data->regulator_init(rdev->reg_data);
                if (ret < 0)
                        goto clean;
@@ -2768,7 +2770,10 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
        dev_set_drvdata(&rdev->dev, rdev);
 
        /* set regulator constraints */
-       ret = set_machine_constraints(rdev, &init_data->constraints);
+       if (init_data)
+               constraints = &init_data->constraints;
+
+       ret = set_machine_constraints(rdev, constraints);
        if (ret < 0)
                goto scrub;
 
@@ -2777,7 +2782,7 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
        if (ret < 0)
                goto scrub;
 
-       if (init_data->supply_regulator)
+       if (init_data && init_data->supply_regulator)
                supply = init_data->supply_regulator;
        else if (regulator_desc->supply_name)
                supply = regulator_desc->supply_name;
@@ -2799,15 +2804,17 @@ struct regulator_dev *regulator_register(struct regulator_desc *regulator_desc,
        }
 
        /* add consumers devices */
-       for (i = 0; i < init_data->num_consumer_supplies; i++) {
-               ret = set_consumer_device_supply(rdev,
-                       init_data->consumer_supplies[i].dev,
-                       init_data->consumer_supplies[i].dev_name,
-                       init_data->consumer_supplies[i].supply);
-               if (ret < 0) {
-                       dev_err(dev, "Failed to set supply %s\n",
+       if (init_data) {
+               for (i = 0; i < init_data->num_consumer_supplies; i++) {
+                       ret = set_consumer_device_supply(rdev,
+                               init_data->consumer_supplies[i].dev,
+                               init_data->consumer_supplies[i].dev_name,
                                init_data->consumer_supplies[i].supply);
-                       goto unset_supplies;
+                       if (ret < 0) {
+                               dev_err(dev, "Failed to set supply %s\n",
+                                       init_data->consumer_supplies[i].supply);
+                               goto unset_supplies;
+                       }
                }
        }