149 lines
3.4 KiB
C
149 lines
3.4 KiB
C
/*
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* Moschip MCS814x GPIO support
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*
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* Copyright (C) 2012, Florian Fainelli <florian@openwrt.org>
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*
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* Licensed under the GPLv2
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/gpio.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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struct mcs814x_gpio_chip {
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void __iomem *regs;
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struct gpio_chip chip;
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};
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#define GPIO_PIN 0x00
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#define GPIO_DIR 0x04
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#define to_mcs814x_gpio_chip(x) container_of(x, struct mcs814x_gpio_chip, chip)
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static int mcs814x_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
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return readl_relaxed(mcs814x->regs + GPIO_PIN) & (1 << offset);
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}
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static void mcs814x_gpio_set(struct gpio_chip *chip,
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unsigned offset, int value)
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{
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struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
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u32 mask;
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mask = readl_relaxed(mcs814x->regs + GPIO_PIN);
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if (value)
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mask |= (1 << offset);
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else
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mask &= ~(1 << offset);
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writel_relaxed(mask, mcs814x->regs + GPIO_PIN);
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}
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static int mcs814x_gpio_direction_output(struct gpio_chip *chip,
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unsigned offset, int value)
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{
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struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
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u32 mask;
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mask = readl_relaxed(mcs814x->regs + GPIO_DIR);
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mask &= ~(1 << offset);
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writel_relaxed(mask, mcs814x->regs + GPIO_DIR);
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return 0;
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}
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static int mcs814x_gpio_direction_input(struct gpio_chip *chip,
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unsigned offset)
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{
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struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
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u32 mask;
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mask = readl_relaxed(mcs814x->regs + GPIO_DIR);
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mask |= (1 << offset);
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writel_relaxed(mask, mcs814x->regs + GPIO_DIR);
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return 0;
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}
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static int mcs814x_gpio_probe(struct platform_device *pdev)
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{
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struct resource *res;
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struct mcs814x_gpio_chip *mcs814x_chip;
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int ret;
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const unsigned int *num_gpios;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENODEV;
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num_gpios = of_get_property(pdev->dev.of_node, "num-gpios", NULL);
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if (!num_gpios)
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dev_err(&pdev->dev, "FIXME: no num-gpios property\n");
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mcs814x_chip = kzalloc(sizeof(*mcs814x_chip), GFP_KERNEL);
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if (!mcs814x_chip)
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return -ENOMEM;
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mcs814x_chip->regs = devm_ioremap_resource(&pdev->dev, res);
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if (!mcs814x_chip->regs) {
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ret = -ENOMEM;
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goto out;
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}
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platform_set_drvdata(pdev, mcs814x_chip);
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#ifdef CONFIG_OF_GPIO
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mcs814x_chip->chip.of_node = pdev->dev.of_node;
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#endif
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mcs814x_chip->chip.label = pdev->name;
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mcs814x_chip->chip.get = mcs814x_gpio_get;
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mcs814x_chip->chip.set = mcs814x_gpio_set;
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mcs814x_chip->chip.direction_input = mcs814x_gpio_direction_input;
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mcs814x_chip->chip.direction_output = mcs814x_gpio_direction_output;
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mcs814x_chip->chip.ngpio = be32_to_cpup(num_gpios);
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/* we want dynamic base allocation */
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mcs814x_chip->chip.base = -1;
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ret = gpiochip_add(&mcs814x_chip->chip);
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if (ret) {
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dev_err(&pdev->dev, "failed to register gpiochip\n");
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goto out;
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}
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return 0;
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out:
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platform_set_drvdata(pdev, NULL);
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kfree(mcs814x_chip);
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return ret;
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}
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static struct of_device_id mcs814x_gpio_ids[] = {
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{ .compatible = "moschip,mcs814x-gpio" },
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{ /* sentinel */ },
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};
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static struct platform_driver mcs814x_gpio_driver = {
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.driver = {
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.name = "mcs814x-gpio",
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.owner = THIS_MODULE,
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.of_match_table = mcs814x_gpio_ids,
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},
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.probe = mcs814x_gpio_probe,
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};
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int __init mcs814x_gpio_init(void)
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{
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return platform_driver_register(&mcs814x_gpio_driver);
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}
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postcore_initcall(mcs814x_gpio_init);
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