![Thierry Reding](/assets/img/avatar_default.png)
Looking up init data for regulators found on chips is a common operation that can be handled in a generic way. The new helper function introduced by this patch looks up the children of a given node by names specified in a match table and fills that match table with information parsed from the DT. This is based on work by Rhyland Klein <rklein@nvidia.com>. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
135 lines
4.1 KiB
C
135 lines
4.1 KiB
C
/*
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* OF helpers for regulator framework
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*
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* Copyright (C) 2011 Texas Instruments, Inc.
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* Rajendra Nayak <rnayak@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/regulator/machine.h>
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#include <linux/regulator/of_regulator.h>
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static void of_get_regulation_constraints(struct device_node *np,
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struct regulator_init_data **init_data)
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{
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const __be32 *min_uV, *max_uV, *uV_offset;
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const __be32 *min_uA, *max_uA;
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struct regulation_constraints *constraints = &(*init_data)->constraints;
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constraints->name = of_get_property(np, "regulator-name", NULL);
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min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
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if (min_uV)
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constraints->min_uV = be32_to_cpu(*min_uV);
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max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
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if (max_uV)
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constraints->max_uV = be32_to_cpu(*max_uV);
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/* Voltage change possible? */
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if (constraints->min_uV != constraints->max_uV)
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constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
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/* Only one voltage? Then make sure it's set. */
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if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
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constraints->apply_uV = true;
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uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
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if (uV_offset)
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constraints->uV_offset = be32_to_cpu(*uV_offset);
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min_uA = of_get_property(np, "regulator-min-microamp", NULL);
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if (min_uA)
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constraints->min_uA = be32_to_cpu(*min_uA);
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max_uA = of_get_property(np, "regulator-max-microamp", NULL);
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if (max_uA)
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constraints->max_uA = be32_to_cpu(*max_uA);
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/* Current change possible? */
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if (constraints->min_uA != constraints->max_uA)
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constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
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if (of_find_property(np, "regulator-boot-on", NULL))
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constraints->boot_on = true;
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if (of_find_property(np, "regulator-always-on", NULL))
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constraints->always_on = true;
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else /* status change should be possible if not always on. */
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constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
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}
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/**
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* of_get_regulator_init_data - extract regulator_init_data structure info
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* @dev: device requesting for regulator_init_data
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*
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* Populates regulator_init_data structure by extracting data from device
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* tree node, returns a pointer to the populated struture or NULL if memory
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* alloc fails.
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*/
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struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
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struct device_node *node)
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{
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struct regulator_init_data *init_data;
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if (!node)
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return NULL;
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init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
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if (!init_data)
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return NULL; /* Out of memory? */
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of_get_regulation_constraints(node, &init_data);
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return init_data;
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}
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EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
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/**
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* of_regulator_match - extract regulator init data
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* @dev: device requesting the data
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* @node: parent device node of the regulators
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* @matches: match table for the regulators
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* @num_matches: number of entries in match table
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*
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* This function uses a match table specified by the regulator driver and
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* looks up the corresponding init data in the device tree. Note that the
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* match table is modified in place.
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*
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* Returns the number of matches found or a negative error code on failure.
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*/
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int of_regulator_match(struct device *dev, struct device_node *node,
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struct of_regulator_match *matches,
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unsigned int num_matches)
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{
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unsigned int count = 0;
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unsigned int i;
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if (!dev || !node)
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return -EINVAL;
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for (i = 0; i < num_matches; i++) {
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struct of_regulator_match *match = &matches[i];
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struct device_node *child;
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child = of_find_node_by_name(node, match->name);
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if (!child)
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continue;
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match->init_data = of_get_regulator_init_data(dev, child);
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if (!match->init_data) {
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dev_err(dev, "failed to parse DT for regulator %s\n",
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child->name);
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return -EINVAL;
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}
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match->of_node = child;
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count++;
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}
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return count;
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}
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EXPORT_SYMBOL_GPL(of_regulator_match);
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