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https://github.com/edk2-porting/linux-next.git
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70e703e741
It is pretty helpful to create some kind of device for backing the GPIO chips, especially when preparing the driver for using GENERIC_GPIO, so let's create a simple platform device and a simple platform device driver and create the gpiochip in the .probe() routine for the device driver. Keep all at the core initcall so the behaviour is the same as before. Cc: Keguang Zhang <keguang.zhang@gmail.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: linux-mips@linux-mips.org Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
143 lines
3.1 KiB
C
143 lines
3.1 KiB
C
/*
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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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* 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/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 <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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#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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u32 mask;
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mask = 1 << (gpio + LOONGSON_GPIO_IN_OFFSET);
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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 & mask) != 0;
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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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u32 mask;
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mask = 1 << gpio;
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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 |= mask;
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else
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val &= (~mask);
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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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u32 mask;
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spin_lock(&gpio_lock);
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mask = 1 << gpio;
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temp = LOONGSON_GPIOIE;
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temp |= mask;
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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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u32 mask;
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loongson_gpio_set_value(chip, gpio, level);
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spin_lock(&gpio_lock);
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mask = 1 << gpio;
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temp = LOONGSON_GPIOIE;
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temp &= (~mask);
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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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