linux-stable/drivers/regulator/of_regulator.c
Stephen Warren 13511def87 regulator: deprecate regulator-compatible DT property
When the bindings for the TPS6586x regulator were being proposed, I
asserted that DT node naming rules for bus child nodes should also be
applied to nodes inside the TPS6586x regulator node itself. In other
words, that each node providing regulator init data should be named
after the type of object it represented ("regulator") and hence that
some other property was required to indicate which regulator the node
described ("regulator-compatible"). In turn this led to multiple nodes
having the same name, thus requiring node names to use a unit address
to make them unique, thus requiring reg properties within the nodes and

However, subsequent discussion indicates that the rules I was asserting
only applies to standardized bus nodes, and within a device's own node,
the binding can basically do anything sane that it wants.

Hence, this change deprecates the register-compatible property, and
instead uses node names to replace this functionality. This greatly
simplifies the device tree content, making them smaller and more legible.

The code is changed such that old device trees continue to work.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-09-25 13:44:47 +01:00

152 lines
4.7 KiB
C

/*
* OF helpers for regulator framework
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Rajendra Nayak <rnayak@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
static void of_get_regulation_constraints(struct device_node *np,
struct regulator_init_data **init_data)
{
const __be32 *min_uV, *max_uV, *uV_offset;
const __be32 *min_uA, *max_uA, *ramp_delay;
struct regulation_constraints *constraints = &(*init_data)->constraints;
constraints->name = of_get_property(np, "regulator-name", NULL);
min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
if (min_uV)
constraints->min_uV = be32_to_cpu(*min_uV);
max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
if (max_uV)
constraints->max_uV = be32_to_cpu(*max_uV);
/* Voltage change possible? */
if (constraints->min_uV != constraints->max_uV)
constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
/* Only one voltage? Then make sure it's set. */
if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
constraints->apply_uV = true;
uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
if (uV_offset)
constraints->uV_offset = be32_to_cpu(*uV_offset);
min_uA = of_get_property(np, "regulator-min-microamp", NULL);
if (min_uA)
constraints->min_uA = be32_to_cpu(*min_uA);
max_uA = of_get_property(np, "regulator-max-microamp", NULL);
if (max_uA)
constraints->max_uA = be32_to_cpu(*max_uA);
/* Current change possible? */
if (constraints->min_uA != constraints->max_uA)
constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
if (of_find_property(np, "regulator-boot-on", NULL))
constraints->boot_on = true;
if (of_find_property(np, "regulator-always-on", NULL))
constraints->always_on = true;
else /* status change should be possible if not always on. */
constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL);
if (ramp_delay)
constraints->ramp_delay = be32_to_cpu(*ramp_delay);
}
/**
* of_get_regulator_init_data - extract regulator_init_data structure info
* @dev: device requesting for regulator_init_data
*
* Populates regulator_init_data structure by extracting data from device
* tree node, returns a pointer to the populated struture or NULL if memory
* alloc fails.
*/
struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
struct device_node *node)
{
struct regulator_init_data *init_data;
if (!node)
return NULL;
init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
if (!init_data)
return NULL; /* Out of memory? */
of_get_regulation_constraints(node, &init_data);
return init_data;
}
EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
/**
* of_regulator_match - extract multiple regulator init data from device tree.
* @dev: device requesting the data
* @node: parent device node of the regulators
* @matches: match table for the regulators
* @num_matches: number of entries in match table
*
* This function uses a match table specified by the regulator driver to
* parse regulator init data from the device tree. @node is expected to
* contain a set of child nodes, each providing the init data for one
* regulator. The data parsed from a child node will be matched to a regulator
* based on either the deprecated property regulator-compatible if present,
* or otherwise the child node's name. Note that the match table is modified
* in place.
*
* Returns the number of matches found or a negative error code on failure.
*/
int of_regulator_match(struct device *dev, struct device_node *node,
struct of_regulator_match *matches,
unsigned int num_matches)
{
unsigned int count = 0;
unsigned int i;
const char *name;
struct device_node *child;
if (!dev || !node)
return -EINVAL;
for_each_child_of_node(node, child) {
name = of_get_property(child,
"regulator-compatible", NULL);
if (!name)
name = child->name;
for (i = 0; i < num_matches; i++) {
struct of_regulator_match *match = &matches[i];
if (match->of_node)
continue;
if (strcmp(match->name, name))
continue;
match->init_data =
of_get_regulator_init_data(dev, child);
if (!match->init_data) {
dev_err(dev,
"failed to parse DT for regulator %s\n",
child->name);
return -EINVAL;
}
match->of_node = child;
count++;
break;
}
}
return count;
}
EXPORT_SYMBOL_GPL(of_regulator_match);