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Based on 1 normalized pattern(s): 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 this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
142 lines
3.3 KiB
C
142 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Generic Syscon LEDs Driver
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*
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* Copyright (c) 2014, Linaro Limited
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* Author: Linus Walleij <linus.walleij@linaro.org>
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*/
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#include <linux/io.h>
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#include <linux/init.h>
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#include <linux/of_device.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/stat.h>
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#include <linux/slab.h>
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#include <linux/mfd/syscon.h>
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#include <linux/regmap.h>
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#include <linux/leds.h>
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/**
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* struct syscon_led - state container for syscon based LEDs
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* @cdev: LED class device for this LED
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* @map: regmap to access the syscon device backing this LED
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* @offset: the offset into the syscon regmap for the LED register
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* @mask: the bit in the register corresponding to the LED
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* @state: current state of the LED
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*/
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struct syscon_led {
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struct led_classdev cdev;
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struct regmap *map;
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u32 offset;
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u32 mask;
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bool state;
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};
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static void syscon_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct syscon_led *sled =
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container_of(led_cdev, struct syscon_led, cdev);
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u32 val;
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int ret;
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if (value == LED_OFF) {
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val = 0;
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sled->state = false;
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} else {
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val = sled->mask;
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sled->state = true;
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}
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ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val);
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if (ret < 0)
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dev_err(sled->cdev.dev, "error updating LED status\n");
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}
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static int syscon_led_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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struct device *parent;
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struct regmap *map;
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struct syscon_led *sled;
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const char *state;
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int ret;
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parent = dev->parent;
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if (!parent) {
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dev_err(dev, "no parent for syscon LED\n");
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return -ENODEV;
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}
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map = syscon_node_to_regmap(parent->of_node);
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if (IS_ERR(map)) {
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dev_err(dev, "no regmap for syscon LED parent\n");
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return PTR_ERR(map);
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}
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sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL);
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if (!sled)
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return -ENOMEM;
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sled->map = map;
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if (of_property_read_u32(np, "offset", &sled->offset))
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return -EINVAL;
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if (of_property_read_u32(np, "mask", &sled->mask))
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return -EINVAL;
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sled->cdev.name =
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of_get_property(np, "label", NULL) ? : np->name;
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sled->cdev.default_trigger =
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of_get_property(np, "linux,default-trigger", NULL);
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state = of_get_property(np, "default-state", NULL);
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if (state) {
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if (!strcmp(state, "keep")) {
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u32 val;
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ret = regmap_read(map, sled->offset, &val);
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if (ret < 0)
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return ret;
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sled->state = !!(val & sled->mask);
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} else if (!strcmp(state, "on")) {
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sled->state = true;
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ret = regmap_update_bits(map, sled->offset,
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sled->mask,
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sled->mask);
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if (ret < 0)
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return ret;
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} else {
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sled->state = false;
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ret = regmap_update_bits(map, sled->offset,
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sled->mask, 0);
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if (ret < 0)
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return ret;
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}
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}
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sled->cdev.brightness_set = syscon_led_set;
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ret = led_classdev_register(dev, &sled->cdev);
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if (ret < 0)
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return ret;
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platform_set_drvdata(pdev, sled);
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dev_info(dev, "registered LED %s\n", sled->cdev.name);
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return 0;
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}
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static const struct of_device_id of_syscon_leds_match[] = {
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{ .compatible = "register-bit-led", },
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{},
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};
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static struct platform_driver syscon_led_driver = {
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.probe = syscon_led_probe,
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.driver = {
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.name = "leds-syscon",
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.of_match_table = of_syscon_leds_match,
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.suppress_bind_attrs = true,
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},
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};
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builtin_platform_driver(syscon_led_driver);
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