gpio: add lpc18xx gpio driver (13a43fd9) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/gpio/Kconfig

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		@@ -230,6 +230,14 @@ config GPIO_LOONGSON
		help
		driver for GPIO functionality on Loongson-2F/3A/3B processors.

		config GPIO_LPC18XX
		bool "NXP LPC18XX/43XX GPIO support"
		default y if ARCH_LPC18XX
		depends on OF_GPIO && (ARCH_LPC18XX \|\| COMPILE_TEST)
		help
		Select this option to enable GPIO driver for
		NXP LPC18XX/43XX devices.

		config GPIO_LYNXPOINT
		tristate "Intel Lynxpoint GPIO support"
		depends on ACPI && X86

drivers/gpio/Makefile

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		@@ -44,6 +44,7 @@ obj-$(CONFIG_ARCH_KS8695) += gpio-ks8695.o
		obj-$(CONFIG_GPIO_INTEL_MID) += gpio-intel-mid.o
		obj-$(CONFIG_GPIO_LOONGSON) += gpio-loongson.o
		obj-$(CONFIG_GPIO_LP3943) += gpio-lp3943.o
		obj-$(CONFIG_GPIO_LPC18XX) += gpio-lpc18xx.o
		obj-$(CONFIG_ARCH_LPC32XX) += gpio-lpc32xx.o
		obj-$(CONFIG_GPIO_LYNXPOINT) += gpio-lynxpoint.o
		obj-$(CONFIG_GPIO_MAX730X) += gpio-max730x.o

drivers/gpio/gpio-lpc18xx.c

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		/*
		* GPIO driver for NXP LPC18xx/43xx.
		*
		* Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 as
		* published by the Free Software Foundation.
		*
		*/

		#include <linux/clk.h>
		#include <linux/gpio/driver.h>
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/of_gpio.h>
		#include <linux/pinctrl/consumer.h>
		#include <linux/platform_device.h>

		/* LPC18xx GPIO register offsets */
		#define LPC18XX_REG_DIR(n) (0x2000 + n * sizeof(u32))

		#define LPC18XX_MAX_PORTS 8
		#define LPC18XX_PINS_PER_PORT 32

		struct lpc18xx_gpio_chip {
		struct gpio_chip gpio;
		void __iomem *base;
		struct clk *clk;
		spinlock_t lock;
		};

		static inline struct lpc18xx_gpio_chip to_lpc18xx_gpio(struct gpio_chip chip)
		{
		return container_of(chip, struct lpc18xx_gpio_chip, gpio);
		}

		static int lpc18xx_gpio_request(struct gpio_chip *chip, unsigned offset)
		{
		return pinctrl_request_gpio(offset);
		}

		static void lpc18xx_gpio_free(struct gpio_chip *chip, unsigned offset)
		{
		pinctrl_free_gpio(offset);
		}

		static void lpc18xx_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
		{
		struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip);
		writeb(value ? 1 : 0, gc->base + offset);
		}

		static int lpc18xx_gpio_get(struct gpio_chip *chip, unsigned offset)
		{
		struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip);
		return !!readb(gc->base + offset);
		}

		static int lpc18xx_gpio_direction(struct gpio_chip *chip, unsigned offset,
		bool out)
		{
		struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip);
		unsigned long flags;
		u32 port, pin, dir;

		port = offset / LPC18XX_PINS_PER_PORT;
		pin = offset % LPC18XX_PINS_PER_PORT;

		spin_lock_irqsave(&gc->lock, flags);
		dir = readl(gc->base + LPC18XX_REG_DIR(port));
		if (out)
		dir \|= BIT(pin);
		else
		dir &= ~BIT(pin);
		writel(dir, gc->base + LPC18XX_REG_DIR(port));
		spin_unlock_irqrestore(&gc->lock, flags);

		return 0;
		}

		static int lpc18xx_gpio_direction_input(struct gpio_chip *chip,
		unsigned offset)
		{
		return lpc18xx_gpio_direction(chip, offset, false);
		}

		static int lpc18xx_gpio_direction_output(struct gpio_chip *chip,
		unsigned offset, int value)
		{
		lpc18xx_gpio_set(chip, offset, value);
		return lpc18xx_gpio_direction(chip, offset, true);
		}

		static struct gpio_chip lpc18xx_chip = {
		.label = "lpc18xx/43xx-gpio",
		.request = lpc18xx_gpio_request,
		.free = lpc18xx_gpio_free,
		.direction_input = lpc18xx_gpio_direction_input,
		.direction_output = lpc18xx_gpio_direction_output,
		.set = lpc18xx_gpio_set,
		.get = lpc18xx_gpio_get,
		.ngpio = LPC18XX_MAX_PORTS * LPC18XX_PINS_PER_PORT,
		.owner = THIS_MODULE,
		};

		static int lpc18xx_gpio_probe(struct platform_device *pdev)
		{
		struct lpc18xx_gpio_chip *gc;
		struct resource *res;
		int ret;

		gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
		if (!gc)
		return -ENOMEM;

		gc->gpio = lpc18xx_chip;
		platform_set_drvdata(pdev, gc);

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		gc->base = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(gc->base))
		return PTR_ERR(gc->base);

		gc->clk = devm_clk_get(&pdev->dev, NULL);
		if (IS_ERR(gc->clk)) {
		dev_err(&pdev->dev, "input clock not found\n");
		return PTR_ERR(gc->clk);
		}

		ret = clk_prepare_enable(gc->clk);
		if (ret) {
		dev_err(&pdev->dev, "unable to enable clock\n");
		return ret;
		}

		spin_lock_init(&gc->lock);

		gc->gpio.dev = &pdev->dev;

		ret = gpiochip_add(&gc->gpio);
		if (ret) {
		dev_err(&pdev->dev, "failed to add gpio chip\n");
		clk_disable_unprepare(gc->clk);
		return ret;
		}

		return 0;
		}

		static int lpc18xx_gpio_remove(struct platform_device *pdev)
		{
		struct lpc18xx_gpio_chip *gc = platform_get_drvdata(pdev);

		gpiochip_remove(&gc->gpio);
		clk_disable_unprepare(gc->clk);

		return 0;
		}

		static const struct of_device_id lpc18xx_gpio_match[] = {
		{ .compatible = "nxp,lpc1850-gpio" },
		{ }
		};
		MODULE_DEVICE_TABLE(of, lpc18xx_gpio_match);

		static struct platform_driver lpc18xx_gpio_driver = {
		.probe = lpc18xx_gpio_probe,
		.remove = lpc18xx_gpio_remove,
		.driver = {
		.name = "lpc18xx-gpio",
		.of_match_table = lpc18xx_gpio_match,
		},
		};
		module_platform_driver(lpc18xx_gpio_driver);

		MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
		MODULE_DESCRIPTION("GPIO driver for LPC18xx/43xx");
		MODULE_LICENSE("GPL v2");