Joachim Eastwood | 13a43fd | 2015-05-02 23:11:34 +0200 | [diff] [blame] | 1 | /* |
| 2 | * GPIO driver for NXP LPC18xx/43xx. |
| 3 | * |
| 4 | * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <linux/clk.h> |
| 13 | #include <linux/gpio/driver.h> |
| 14 | #include <linux/io.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/of.h> |
| 17 | #include <linux/of_gpio.h> |
| 18 | #include <linux/pinctrl/consumer.h> |
| 19 | #include <linux/platform_device.h> |
| 20 | |
| 21 | /* LPC18xx GPIO register offsets */ |
| 22 | #define LPC18XX_REG_DIR(n) (0x2000 + n * sizeof(u32)) |
| 23 | |
| 24 | #define LPC18XX_MAX_PORTS 8 |
| 25 | #define LPC18XX_PINS_PER_PORT 32 |
| 26 | |
| 27 | struct lpc18xx_gpio_chip { |
| 28 | struct gpio_chip gpio; |
| 29 | void __iomem *base; |
| 30 | struct clk *clk; |
| 31 | spinlock_t lock; |
| 32 | }; |
| 33 | |
| 34 | static inline struct lpc18xx_gpio_chip *to_lpc18xx_gpio(struct gpio_chip *chip) |
| 35 | { |
| 36 | return container_of(chip, struct lpc18xx_gpio_chip, gpio); |
| 37 | } |
| 38 | |
Joachim Eastwood | 13a43fd | 2015-05-02 23:11:34 +0200 | [diff] [blame] | 39 | static void lpc18xx_gpio_set(struct gpio_chip *chip, unsigned offset, int value) |
| 40 | { |
| 41 | struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip); |
| 42 | writeb(value ? 1 : 0, gc->base + offset); |
| 43 | } |
| 44 | |
| 45 | static int lpc18xx_gpio_get(struct gpio_chip *chip, unsigned offset) |
| 46 | { |
| 47 | struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip); |
| 48 | return !!readb(gc->base + offset); |
| 49 | } |
| 50 | |
| 51 | static int lpc18xx_gpio_direction(struct gpio_chip *chip, unsigned offset, |
| 52 | bool out) |
| 53 | { |
| 54 | struct lpc18xx_gpio_chip *gc = to_lpc18xx_gpio(chip); |
| 55 | unsigned long flags; |
| 56 | u32 port, pin, dir; |
| 57 | |
| 58 | port = offset / LPC18XX_PINS_PER_PORT; |
| 59 | pin = offset % LPC18XX_PINS_PER_PORT; |
| 60 | |
| 61 | spin_lock_irqsave(&gc->lock, flags); |
| 62 | dir = readl(gc->base + LPC18XX_REG_DIR(port)); |
| 63 | if (out) |
| 64 | dir |= BIT(pin); |
| 65 | else |
| 66 | dir &= ~BIT(pin); |
| 67 | writel(dir, gc->base + LPC18XX_REG_DIR(port)); |
| 68 | spin_unlock_irqrestore(&gc->lock, flags); |
| 69 | |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | static int lpc18xx_gpio_direction_input(struct gpio_chip *chip, |
| 74 | unsigned offset) |
| 75 | { |
| 76 | return lpc18xx_gpio_direction(chip, offset, false); |
| 77 | } |
| 78 | |
| 79 | static int lpc18xx_gpio_direction_output(struct gpio_chip *chip, |
| 80 | unsigned offset, int value) |
| 81 | { |
| 82 | lpc18xx_gpio_set(chip, offset, value); |
| 83 | return lpc18xx_gpio_direction(chip, offset, true); |
| 84 | } |
| 85 | |
| 86 | static struct gpio_chip lpc18xx_chip = { |
| 87 | .label = "lpc18xx/43xx-gpio", |
Jonas Gorski | 203f0da | 2015-10-11 17:34:16 +0200 | [diff] [blame] | 88 | .request = gpiochip_generic_request, |
| 89 | .free = gpiochip_generic_free, |
Joachim Eastwood | 13a43fd | 2015-05-02 23:11:34 +0200 | [diff] [blame] | 90 | .direction_input = lpc18xx_gpio_direction_input, |
| 91 | .direction_output = lpc18xx_gpio_direction_output, |
| 92 | .set = lpc18xx_gpio_set, |
| 93 | .get = lpc18xx_gpio_get, |
| 94 | .ngpio = LPC18XX_MAX_PORTS * LPC18XX_PINS_PER_PORT, |
| 95 | .owner = THIS_MODULE, |
| 96 | }; |
| 97 | |
| 98 | static int lpc18xx_gpio_probe(struct platform_device *pdev) |
| 99 | { |
| 100 | struct lpc18xx_gpio_chip *gc; |
| 101 | struct resource *res; |
| 102 | int ret; |
| 103 | |
| 104 | gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL); |
| 105 | if (!gc) |
| 106 | return -ENOMEM; |
| 107 | |
| 108 | gc->gpio = lpc18xx_chip; |
| 109 | platform_set_drvdata(pdev, gc); |
| 110 | |
| 111 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 112 | gc->base = devm_ioremap_resource(&pdev->dev, res); |
| 113 | if (IS_ERR(gc->base)) |
| 114 | return PTR_ERR(gc->base); |
| 115 | |
| 116 | gc->clk = devm_clk_get(&pdev->dev, NULL); |
| 117 | if (IS_ERR(gc->clk)) { |
| 118 | dev_err(&pdev->dev, "input clock not found\n"); |
| 119 | return PTR_ERR(gc->clk); |
| 120 | } |
| 121 | |
| 122 | ret = clk_prepare_enable(gc->clk); |
| 123 | if (ret) { |
| 124 | dev_err(&pdev->dev, "unable to enable clock\n"); |
| 125 | return ret; |
| 126 | } |
| 127 | |
| 128 | spin_lock_init(&gc->lock); |
| 129 | |
Linus Walleij | 58383c7 | 2015-11-04 09:56:26 +0100 | [diff] [blame^] | 130 | gc->gpio.parent = &pdev->dev; |
Joachim Eastwood | 13a43fd | 2015-05-02 23:11:34 +0200 | [diff] [blame] | 131 | |
| 132 | ret = gpiochip_add(&gc->gpio); |
| 133 | if (ret) { |
| 134 | dev_err(&pdev->dev, "failed to add gpio chip\n"); |
| 135 | clk_disable_unprepare(gc->clk); |
| 136 | return ret; |
| 137 | } |
| 138 | |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | static int lpc18xx_gpio_remove(struct platform_device *pdev) |
| 143 | { |
| 144 | struct lpc18xx_gpio_chip *gc = platform_get_drvdata(pdev); |
| 145 | |
| 146 | gpiochip_remove(&gc->gpio); |
| 147 | clk_disable_unprepare(gc->clk); |
| 148 | |
| 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | static const struct of_device_id lpc18xx_gpio_match[] = { |
| 153 | { .compatible = "nxp,lpc1850-gpio" }, |
| 154 | { } |
| 155 | }; |
| 156 | MODULE_DEVICE_TABLE(of, lpc18xx_gpio_match); |
| 157 | |
| 158 | static struct platform_driver lpc18xx_gpio_driver = { |
| 159 | .probe = lpc18xx_gpio_probe, |
| 160 | .remove = lpc18xx_gpio_remove, |
| 161 | .driver = { |
| 162 | .name = "lpc18xx-gpio", |
| 163 | .of_match_table = lpc18xx_gpio_match, |
| 164 | }, |
| 165 | }; |
| 166 | module_platform_driver(lpc18xx_gpio_driver); |
| 167 | |
| 168 | MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>"); |
| 169 | MODULE_DESCRIPTION("GPIO driver for LPC18xx/43xx"); |
| 170 | MODULE_LICENSE("GPL v2"); |