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135 lines
3.0 KiB
135 lines
3.0 KiB
// 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 <[email protected]> |
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* Copyright (c) 2008-2010 Arnaud Patard <[email protected]> |
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* Copyright (c) 2013 Hongbing Hu <[email protected]> |
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* Copyright (c) 2014 Huacai Chen <[email protected]> |
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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_LOONGSON64 |
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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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