mfd: Allow mapping regulator supplies to MFD device from children

Occasionally, it is useful to map supplies from a child device onto the
MFD device. A typical usecase for this would be if the MFD device is
represented as a single node in device tree. All supplies will be
defined in device tree as existing on the MFD device. When a child
depends on frameworks which might have no knowledge of MFD to lookup
supplies on its behalf the supply will not be found.

This patch adds a list of supplies that should be looked up on the
parent rather than the child as part of the mfd_cell structure.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index f421586..adc8ea3 100644 (file)
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/irqdomain.h>
 #include <linux/of.h>
+#include <linux/regulator/consumer.h>
 
 static struct device_type mfd_dev_type = {
        .name   = "mfd_device",
@@ -99,6 +100,13 @@ static int mfd_add_device(struct device *parent, int id,
        pdev->dev.dma_mask = parent->dma_mask;
        pdev->dev.dma_parms = parent->dma_parms;
 
+       ret = devm_regulator_bulk_register_supply_alias(
+                       &pdev->dev, cell->parent_supplies,
+                       parent, cell->parent_supplies,
+                       cell->num_parent_supplies);
+       if (ret < 0)
+               goto fail_res;
+
        if (parent->of_node && cell->of_compatible) {
                for_each_child_of_node(parent->of_node, np) {
                        if (of_device_is_compatible(np, cell->of_compatible)) {
@@ -112,12 +120,12 @@ static int mfd_add_device(struct device *parent, int id,
                ret = platform_device_add_data(pdev,
                                        cell->platform_data, cell->pdata_size);
                if (ret)
-                       goto fail_res;
+                       goto fail_alias;
        }
 
        ret = mfd_platform_add_cell(pdev, cell);
        if (ret)
-               goto fail_res;
+               goto fail_alias;
 
        for (r = 0; r < cell->num_resources; r++) {
                res[r].name = cell->resources[r].name;
@@ -152,17 +160,17 @@ static int mfd_add_device(struct device *parent, int id,
                if (!cell->ignore_resource_conflicts) {
                        ret = acpi_check_resource_conflict(&res[r]);
                        if (ret)
-                               goto fail_res;
+                               goto fail_alias;
                }
        }
 
        ret = platform_device_add_resources(pdev, res, cell->num_resources);
        if (ret)
-               goto fail_res;
+               goto fail_alias;
 
        ret = platform_device_add(pdev);
        if (ret)
-               goto fail_res;
+               goto fail_alias;
 
        if (cell->pm_runtime_no_callbacks)
                pm_runtime_no_callbacks(&pdev->dev);
@@ -171,6 +179,10 @@ static int mfd_add_device(struct device *parent, int id,
 
        return 0;
 
+fail_alias:
+       devm_regulator_bulk_unregister_supply_alias(&pdev->dev,
+                                                   cell->parent_supplies,
+                                                   cell->num_parent_supplies);
 fail_res:
        kfree(res);
 fail_device:

diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
index cebe97e..7314fc4 100644 (file)
--- a/include/linux/mfd/core.h
+++ b/include/linux/mfd/core.h
@@ -59,6 +59,12 @@ struct mfd_cell {
         * pm_runtime_no_callbacks().
         */
        bool                    pm_runtime_no_callbacks;
+
+       /* A list of regulator supplies that should be mapped to the MFD
+        * device rather than the child device when requested
+        */
+       const char              **parent_supplies;
+       int                     num_parent_supplies;
 };
 
 /*