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2874c5fd28
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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
135 lines
3 KiB
C
135 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Loongson-2F/3A/3B GPIO Support
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*
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* Copyright (c) 2008 Richard Liu, STMicroelectronics <richard.liu@st.com>
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* Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com>
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* Copyright (c) 2013 Hongbing Hu <huhb@lemote.com>
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* Copyright (c) 2014 Huacai Chen <chenhc@lemote.com>
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/err.h>
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#include <linux/gpio/driver.h>
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#include <linux/platform_device.h>
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#include <linux/bitops.h>
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#include <asm/types.h>
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#include <loongson.h>
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#define STLS2F_N_GPIO 4
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#define STLS3A_N_GPIO 16
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#ifdef CONFIG_CPU_LOONGSON3
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#define LOONGSON_N_GPIO STLS3A_N_GPIO
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#else
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#define LOONGSON_N_GPIO STLS2F_N_GPIO
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#endif
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/*
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* Offset into the register where we read lines, we write them from offset 0.
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* This offset is the only thing that stand between us and using
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* GPIO_GENERIC.
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*/
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#define LOONGSON_GPIO_IN_OFFSET 16
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static DEFINE_SPINLOCK(gpio_lock);
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static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
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{
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u32 val;
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spin_lock(&gpio_lock);
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val = LOONGSON_GPIODATA;
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spin_unlock(&gpio_lock);
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return !!(val & BIT(gpio + LOONGSON_GPIO_IN_OFFSET));
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}
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static void loongson_gpio_set_value(struct gpio_chip *chip,
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unsigned gpio, int value)
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{
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u32 val;
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spin_lock(&gpio_lock);
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val = LOONGSON_GPIODATA;
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if (value)
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val |= BIT(gpio);
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else
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val &= ~BIT(gpio);
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LOONGSON_GPIODATA = val;
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spin_unlock(&gpio_lock);
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}
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static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
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{
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u32 temp;
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spin_lock(&gpio_lock);
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temp = LOONGSON_GPIOIE;
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temp |= BIT(gpio);
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LOONGSON_GPIOIE = temp;
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spin_unlock(&gpio_lock);
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return 0;
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}
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static int loongson_gpio_direction_output(struct gpio_chip *chip,
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unsigned gpio, int level)
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{
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u32 temp;
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loongson_gpio_set_value(chip, gpio, level);
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spin_lock(&gpio_lock);
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temp = LOONGSON_GPIOIE;
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temp &= ~BIT(gpio);
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LOONGSON_GPIOIE = temp;
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spin_unlock(&gpio_lock);
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return 0;
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}
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static int loongson_gpio_probe(struct platform_device *pdev)
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{
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struct gpio_chip *gc;
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struct device *dev = &pdev->dev;
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gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
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if (!gc)
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return -ENOMEM;
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gc->label = "loongson-gpio-chip";
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gc->base = 0;
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gc->ngpio = LOONGSON_N_GPIO;
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gc->get = loongson_gpio_get_value;
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gc->set = loongson_gpio_set_value;
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gc->direction_input = loongson_gpio_direction_input;
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gc->direction_output = loongson_gpio_direction_output;
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return gpiochip_add_data(gc, NULL);
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}
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static struct platform_driver loongson_gpio_driver = {
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.driver = {
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.name = "loongson-gpio",
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},
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.probe = loongson_gpio_probe,
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};
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static int __init loongson_gpio_setup(void)
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{
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struct platform_device *pdev;
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int ret;
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ret = platform_driver_register(&loongson_gpio_driver);
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if (ret) {
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pr_err("error registering loongson GPIO driver\n");
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return ret;
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}
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pdev = platform_device_register_simple("loongson-gpio", -1, NULL, 0);
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return PTR_ERR_OR_ZERO(pdev);
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}
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postcore_initcall(loongson_gpio_setup);
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