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![Linus Walleij](/assets/img/avatar_default.png)
This pushes the handling of inversion semantics and open drain settings to the GPIO descriptor and gpiolib. All affected board files are also augmented. This is especially nice since we don't have to have any confusing flags passed around to the left and right littering the fixed and GPIO regulator drivers and the regulator core. It is all just very straight-forward: the core asks the GPIO line to be asserted or deasserted and gpiolib deals with the rest depending on how the platform is configured: if the line is active low, it deals with that, if the line is open drain, it deals with that too. Cc: Alexander Shiyan <shc_work@mail.ru> # i.MX boards user Cc: Haojian Zhuang <haojian.zhuang@gmail.com> # MMP2 maintainer Cc: Aaro Koskinen <aaro.koskinen@iki.fi> # OMAP1 maintainer Cc: Tony Lindgren <tony@atomide.com> # OMAP1,2,3 maintainer Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> # EM-X270 maintainer Cc: Robert Jarzmik <robert.jarzmik@free.fr> # EZX maintainer Cc: Philipp Zabel <philipp.zabel@gmail.com> # Magician maintainer Cc: Petr Cvek <petr.cvek@tul.cz> # Magician Cc: Robert Jarzmik <robert.jarzmik@free.fr> # PXA Cc: Paul Parsons <lost.distance@yahoo.com> # hx4700 Cc: Daniel Mack <zonque@gmail.com> # Raumfeld maintainer Cc: Marc Zyngier <marc.zyngier@arm.com> # Zeus maintainer Cc: Geert Uytterhoeven <geert+renesas@glider.be> # SuperH pinctrl/GPIO maintainer Cc: Russell King <rmk+kernel@armlinux.org.uk> # SA1100 Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Janusz Krzysztofik <jmkrzyszt@gmail.com> #OMAP1 Amstrad Delta Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
227 lines
6.1 KiB
C
227 lines
6.1 KiB
C
/*
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* fixed.c
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*
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* Copyright 2008 Wolfson Microelectronics PLC.
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*
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* Copyright (c) 2009 Nokia Corporation
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* Roger Quadros <ext-roger.quadros@nokia.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This is useful for systems with mixed controllable and
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* non-controllable regulators, as well as for allowing testing on
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* systems with no controllable regulators.
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*/
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/fixed.h>
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#include <linux/gpio/consumer.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#include <linux/regulator/of_regulator.h>
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#include <linux/regulator/machine.h>
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struct fixed_voltage_data {
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struct regulator_desc desc;
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struct regulator_dev *dev;
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};
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/**
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* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
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* @dev: device requesting for fixed_voltage_config
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* @desc: regulator description
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*
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* Populates fixed_voltage_config structure by extracting data from device
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* tree node, returns a pointer to the populated structure of NULL if memory
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* alloc fails.
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*/
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static struct fixed_voltage_config *
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of_get_fixed_voltage_config(struct device *dev,
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const struct regulator_desc *desc)
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{
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struct fixed_voltage_config *config;
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struct device_node *np = dev->of_node;
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struct regulator_init_data *init_data;
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config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
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GFP_KERNEL);
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if (!config)
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return ERR_PTR(-ENOMEM);
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config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
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if (!config->init_data)
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return ERR_PTR(-EINVAL);
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init_data = config->init_data;
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init_data->constraints.apply_uV = 0;
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config->supply_name = init_data->constraints.name;
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if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
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config->microvolts = init_data->constraints.min_uV;
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} else {
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dev_err(dev,
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"Fixed regulator specified with variable voltages\n");
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return ERR_PTR(-EINVAL);
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}
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if (init_data->constraints.boot_on)
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config->enabled_at_boot = true;
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of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
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if (of_find_property(np, "vin-supply", NULL))
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config->input_supply = "vin";
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return config;
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}
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static struct regulator_ops fixed_voltage_ops = {
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};
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static int reg_fixed_voltage_probe(struct platform_device *pdev)
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{
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struct fixed_voltage_config *config;
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struct fixed_voltage_data *drvdata;
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struct regulator_config cfg = { };
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enum gpiod_flags gflags;
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int ret;
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drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
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GFP_KERNEL);
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if (!drvdata)
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return -ENOMEM;
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if (pdev->dev.of_node) {
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config = of_get_fixed_voltage_config(&pdev->dev,
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&drvdata->desc);
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if (IS_ERR(config))
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return PTR_ERR(config);
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} else {
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config = dev_get_platdata(&pdev->dev);
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}
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if (!config)
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return -ENOMEM;
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drvdata->desc.name = devm_kstrdup(&pdev->dev,
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config->supply_name,
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GFP_KERNEL);
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if (drvdata->desc.name == NULL) {
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dev_err(&pdev->dev, "Failed to allocate supply name\n");
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return -ENOMEM;
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}
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drvdata->desc.type = REGULATOR_VOLTAGE;
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drvdata->desc.owner = THIS_MODULE;
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drvdata->desc.ops = &fixed_voltage_ops;
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drvdata->desc.enable_time = config->startup_delay;
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if (config->input_supply) {
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drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
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config->input_supply,
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GFP_KERNEL);
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if (!drvdata->desc.supply_name) {
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dev_err(&pdev->dev,
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"Failed to allocate input supply\n");
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return -ENOMEM;
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}
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}
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if (config->microvolts)
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drvdata->desc.n_voltages = 1;
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drvdata->desc.fixed_uV = config->microvolts;
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/*
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* The signal will be inverted by the GPIO core if flagged so in the
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* decriptor.
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*/
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if (config->enabled_at_boot)
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gflags = GPIOD_OUT_HIGH;
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else
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gflags = GPIOD_OUT_LOW;
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/*
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* Some fixed regulators share the enable line between two
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* regulators which makes it necessary to get a handle on the
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* same descriptor for two different consumers. This will get
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* the GPIO descriptor, but only the first call will initialize
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* it so any flags such as inversion or open drain will only
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* be set up by the first caller and assumed identical on the
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* next caller.
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*
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* FIXME: find a better way to deal with this.
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*/
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gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
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/*
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* Do not use devm* here: the regulator core takes over the
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* lifecycle management of the GPIO descriptor.
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*/
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cfg.ena_gpiod = gpiod_get_optional(&pdev->dev, NULL, gflags);
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if (IS_ERR(cfg.ena_gpiod))
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return PTR_ERR(cfg.ena_gpiod);
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cfg.dev = &pdev->dev;
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cfg.init_data = config->init_data;
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cfg.driver_data = drvdata;
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cfg.of_node = pdev->dev.of_node;
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drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
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&cfg);
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if (IS_ERR(drvdata->dev)) {
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ret = PTR_ERR(drvdata->dev);
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dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
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return ret;
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}
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platform_set_drvdata(pdev, drvdata);
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dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
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drvdata->desc.fixed_uV);
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return 0;
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}
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#if defined(CONFIG_OF)
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static const struct of_device_id fixed_of_match[] = {
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{ .compatible = "regulator-fixed", },
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{},
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};
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MODULE_DEVICE_TABLE(of, fixed_of_match);
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#endif
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static struct platform_driver regulator_fixed_voltage_driver = {
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.probe = reg_fixed_voltage_probe,
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.driver = {
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.name = "reg-fixed-voltage",
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.of_match_table = of_match_ptr(fixed_of_match),
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},
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};
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static int __init regulator_fixed_voltage_init(void)
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{
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return platform_driver_register(®ulator_fixed_voltage_driver);
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}
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subsys_initcall(regulator_fixed_voltage_init);
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static void __exit regulator_fixed_voltage_exit(void)
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{
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platform_driver_unregister(®ulator_fixed_voltage_driver);
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}
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module_exit(regulator_fixed_voltage_exit);
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MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
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MODULE_DESCRIPTION("Fixed voltage regulator");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:reg-fixed-voltage");
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