| 1 | /* |
| 2 | * Moschip MCS814x GPIO support |
| 3 | * |
| 4 | * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org> |
| 5 | * |
| 6 | * Licensed under the GPLv2 |
| 7 | */ |
| 8 | |
| 9 | #include <linux/init.h> |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/platform_device.h> |
| 14 | #include <linux/gpio.h> |
| 15 | #include <linux/io.h> |
| 16 | #include <linux/of.h> |
| 17 | #include <linux/of_address.h> |
| 18 | |
| 19 | struct mcs814x_gpio_chip { |
| 20 | void __iomem *regs; |
| 21 | struct gpio_chip chip; |
| 22 | }; |
| 23 | |
| 24 | #define GPIO_PIN 0x00 |
| 25 | #define GPIO_DIR 0x04 |
| 26 | |
| 27 | #define to_mcs814x_gpio_chip(x) container_of(x, struct mcs814x_gpio_chip, chip) |
| 28 | |
| 29 | static int mcs814x_gpio_get(struct gpio_chip *chip, unsigned offset) |
| 30 | { |
| 31 | struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip); |
| 32 | |
| 33 | return readl_relaxed(mcs814x->regs + GPIO_PIN) & (1 << offset); |
| 34 | } |
| 35 | |
| 36 | static void mcs814x_gpio_set(struct gpio_chip *chip, |
| 37 | unsigned offset, int value) |
| 38 | { |
| 39 | struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip); |
| 40 | u32 mask; |
| 41 | |
| 42 | mask = readl_relaxed(mcs814x->regs + GPIO_PIN); |
| 43 | if (value) |
| 44 | mask |= (1 << offset); |
| 45 | else |
| 46 | mask &= ~(1 << offset); |
| 47 | writel_relaxed(mask, mcs814x->regs + GPIO_PIN); |
| 48 | } |
| 49 | |
| 50 | static int mcs814x_gpio_direction_output(struct gpio_chip *chip, |
| 51 | unsigned offset, int value) |
| 52 | { |
| 53 | struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip); |
| 54 | u32 mask; |
| 55 | |
| 56 | mask = readl_relaxed(mcs814x->regs + GPIO_DIR); |
| 57 | mask &= ~(1 << offset); |
| 58 | writel_relaxed(mask, mcs814x->regs + GPIO_DIR); |
| 59 | |
| 60 | return 0; |
| 61 | } |
| 62 | |
| 63 | static int mcs814x_gpio_direction_input(struct gpio_chip *chip, |
| 64 | unsigned offset) |
| 65 | { |
| 66 | struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip); |
| 67 | u32 mask; |
| 68 | |
| 69 | mask = readl_relaxed(mcs814x->regs + GPIO_DIR); |
| 70 | mask |= (1 << offset); |
| 71 | writel_relaxed(mask, mcs814x->regs + GPIO_DIR); |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | static int __devinit mcs814x_gpio_probe(struct platform_device *pdev) |
| 77 | { |
| 78 | struct resource *res; |
| 79 | struct mcs814x_gpio_chip *mcs814x_chip; |
| 80 | int ret; |
| 81 | const unsigned int *num_gpios; |
| 82 | |
| 83 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 84 | if (!res) |
| 85 | return -ENODEV; |
| 86 | |
| 87 | num_gpios = of_get_property(pdev->dev.of_node, "num-gpios", NULL); |
| 88 | if (!num_gpios) |
| 89 | dev_err(&pdev->dev, "FIXME: no num-gpios property\n"); |
| 90 | |
| 91 | mcs814x_chip = kzalloc(sizeof(*mcs814x_chip), GFP_KERNEL); |
| 92 | if (!mcs814x_chip) |
| 93 | return -ENOMEM; |
| 94 | |
| 95 | mcs814x_chip->regs = devm_request_and_ioremap(&pdev->dev, res); |
| 96 | if (!mcs814x_chip->regs) { |
| 97 | ret = -ENOMEM; |
| 98 | goto out; |
| 99 | } |
| 100 | |
| 101 | platform_set_drvdata(pdev, mcs814x_chip); |
| 102 | |
| 103 | #ifdef CONFIG_OF_GPIO |
| 104 | mcs814x_chip->chip.of_node = pdev->dev.of_node; |
| 105 | #endif |
| 106 | |
| 107 | mcs814x_chip->chip.label = pdev->name; |
| 108 | mcs814x_chip->chip.get = mcs814x_gpio_get; |
| 109 | mcs814x_chip->chip.set = mcs814x_gpio_set; |
| 110 | mcs814x_chip->chip.direction_input = mcs814x_gpio_direction_input; |
| 111 | mcs814x_chip->chip.direction_output = mcs814x_gpio_direction_output; |
| 112 | mcs814x_chip->chip.ngpio = be32_to_cpup(num_gpios); |
| 113 | /* we want dynamic base allocation */ |
| 114 | mcs814x_chip->chip.base = -1; |
| 115 | |
| 116 | ret = gpiochip_add(&mcs814x_chip->chip); |
| 117 | if (ret) { |
| 118 | dev_err(&pdev->dev, "failed to register gpiochip\n"); |
| 119 | goto out; |
| 120 | } |
| 121 | |
| 122 | return 0; |
| 123 | |
| 124 | out: |
| 125 | platform_set_drvdata(pdev, NULL); |
| 126 | kfree(mcs814x_chip); |
| 127 | return ret; |
| 128 | } |
| 129 | |
| 130 | static struct of_device_id mcs814x_gpio_ids[] __devinitdata = { |
| 131 | { .compatible = "moschip,mcs814x-gpio" }, |
| 132 | { /* sentinel */ }, |
| 133 | }; |
| 134 | |
| 135 | static struct platform_driver mcs814x_gpio_driver = { |
| 136 | .driver = { |
| 137 | .name = "mcs814x-gpio", |
| 138 | .owner = THIS_MODULE, |
| 139 | .of_match_table = mcs814x_gpio_ids, |
| 140 | }, |
| 141 | .probe = mcs814x_gpio_probe, |
| 142 | }; |
| 143 | |
| 144 | int __init mcs814x_gpio_init(void) |
| 145 | { |
| 146 | return platform_driver_register(&mcs814x_gpio_driver); |
| 147 | } |
| 148 | postcore_initcall(mcs814x_gpio_init); |
| 149 | |
