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![Julia Lawall](/assets/img/avatar_default.png)
These structures are only used to copy into other structures, so declare them as const. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r disable optional_qualifier@ identifier i; position p; @@ static struct gpio_chip i@p = { ... }; @ok@ identifier r.i; expression e; position p; @@ e = i@p; @bad@ position p != {r.p,ok.p}; identifier r.i; struct gpio_chip e; @@ e@i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct gpio_chip i = { ... }; // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Acked-by: Joachim Eastwood <manabian@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
165 lines
4 KiB
C
165 lines
4 KiB
C
/*
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* GPIO driver for NXP LPC18xx/43xx.
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*
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* Copyright (C) 2015 Joachim Eastwood <manabian@gmail.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 version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/clk.h>
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#include <linux/gpio/driver.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_gpio.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/platform_device.h>
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/* LPC18xx GPIO register offsets */
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#define LPC18XX_REG_DIR(n) (0x2000 + n * sizeof(u32))
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#define LPC18XX_MAX_PORTS 8
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#define LPC18XX_PINS_PER_PORT 32
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struct lpc18xx_gpio_chip {
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struct gpio_chip gpio;
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void __iomem *base;
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struct clk *clk;
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spinlock_t lock;
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};
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static void lpc18xx_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
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writeb(value ? 1 : 0, gc->base + offset);
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}
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static int lpc18xx_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
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return !!readb(gc->base + offset);
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}
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static int lpc18xx_gpio_direction(struct gpio_chip *chip, unsigned offset,
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bool out)
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{
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struct lpc18xx_gpio_chip *gc = gpiochip_get_data(chip);
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unsigned long flags;
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u32 port, pin, dir;
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port = offset / LPC18XX_PINS_PER_PORT;
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pin = offset % LPC18XX_PINS_PER_PORT;
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spin_lock_irqsave(&gc->lock, flags);
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dir = readl(gc->base + LPC18XX_REG_DIR(port));
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if (out)
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dir |= BIT(pin);
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else
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dir &= ~BIT(pin);
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writel(dir, gc->base + LPC18XX_REG_DIR(port));
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spin_unlock_irqrestore(&gc->lock, flags);
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return 0;
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}
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static int lpc18xx_gpio_direction_input(struct gpio_chip *chip,
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unsigned offset)
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{
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return lpc18xx_gpio_direction(chip, offset, false);
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}
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static int lpc18xx_gpio_direction_output(struct gpio_chip *chip,
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unsigned offset, int value)
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{
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lpc18xx_gpio_set(chip, offset, value);
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return lpc18xx_gpio_direction(chip, offset, true);
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}
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static const struct gpio_chip lpc18xx_chip = {
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.label = "lpc18xx/43xx-gpio",
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.request = gpiochip_generic_request,
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.free = gpiochip_generic_free,
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.direction_input = lpc18xx_gpio_direction_input,
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.direction_output = lpc18xx_gpio_direction_output,
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.set = lpc18xx_gpio_set,
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.get = lpc18xx_gpio_get,
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.ngpio = LPC18XX_MAX_PORTS * LPC18XX_PINS_PER_PORT,
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.owner = THIS_MODULE,
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};
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static int lpc18xx_gpio_probe(struct platform_device *pdev)
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{
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struct lpc18xx_gpio_chip *gc;
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struct resource *res;
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int ret;
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gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
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if (!gc)
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return -ENOMEM;
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gc->gpio = lpc18xx_chip;
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platform_set_drvdata(pdev, gc);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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gc->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(gc->base))
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return PTR_ERR(gc->base);
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gc->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(gc->clk)) {
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dev_err(&pdev->dev, "input clock not found\n");
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return PTR_ERR(gc->clk);
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}
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ret = clk_prepare_enable(gc->clk);
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if (ret) {
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dev_err(&pdev->dev, "unable to enable clock\n");
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return ret;
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}
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spin_lock_init(&gc->lock);
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gc->gpio.parent = &pdev->dev;
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ret = gpiochip_add_data(&gc->gpio, gc);
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if (ret) {
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dev_err(&pdev->dev, "failed to add gpio chip\n");
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clk_disable_unprepare(gc->clk);
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return ret;
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}
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return 0;
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}
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static int lpc18xx_gpio_remove(struct platform_device *pdev)
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{
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struct lpc18xx_gpio_chip *gc = platform_get_drvdata(pdev);
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gpiochip_remove(&gc->gpio);
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clk_disable_unprepare(gc->clk);
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return 0;
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}
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static const struct of_device_id lpc18xx_gpio_match[] = {
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{ .compatible = "nxp,lpc1850-gpio" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, lpc18xx_gpio_match);
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static struct platform_driver lpc18xx_gpio_driver = {
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.probe = lpc18xx_gpio_probe,
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.remove = lpc18xx_gpio_remove,
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.driver = {
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.name = "lpc18xx-gpio",
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.of_match_table = lpc18xx_gpio_match,
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},
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};
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module_platform_driver(lpc18xx_gpio_driver);
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MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
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MODULE_DESCRIPTION("GPIO driver for LPC18xx/43xx");
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MODULE_LICENSE("GPL v2");
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