| Paul Mundt | 5505911 | 2010-10-04 02:59:29 +0900 | [diff] [blame^] | 1 | /* |
| 2 | * arch/sh/boards/mach-x3proto/gpio.c |
| 3 | * |
| 4 | * Renesas SH-X3 Prototype Baseboard GPIO Support. |
| 5 | * |
| 6 | * Copyright (C) 2010 Paul Mundt |
| 7 | * |
| 8 | * This file is subject to the terms and conditions of the GNU General Public |
| 9 | * License. See the file "COPYING" in the main directory of this archive |
| 10 | * for more details. |
| 11 | */ |
| 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 13 | |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/interrupt.h> |
| 16 | #include <linux/gpio.h> |
| 17 | #include <linux/irq.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/io.h> |
| 21 | #include <mach/ilsel.h> |
| 22 | #include <mach/hardware.h> |
| 23 | |
| 24 | #define KEYCTLR 0xb81c0000 |
| 25 | #define KEYOUTR 0xb81c0002 |
| 26 | #define KEYDETR 0xb81c0004 |
| 27 | |
| 28 | static DEFINE_SPINLOCK(x3proto_gpio_lock); |
| 29 | static unsigned int x3proto_gpio_irq_map[NR_BASEBOARD_GPIOS] = { 0, }; |
| 30 | |
| 31 | static int x3proto_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) |
| 32 | { |
| 33 | unsigned long flags; |
| 34 | unsigned int data; |
| 35 | |
| 36 | spin_lock_irqsave(&x3proto_gpio_lock, flags); |
| 37 | data = __raw_readw(KEYCTLR); |
| 38 | data |= (1 << gpio); |
| 39 | __raw_writew(data, KEYCTLR); |
| 40 | spin_unlock_irqrestore(&x3proto_gpio_lock, flags); |
| 41 | |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | static int x3proto_gpio_get(struct gpio_chip *chip, unsigned gpio) |
| 46 | { |
| 47 | return !!(__raw_readw(KEYDETR) & (1 << gpio)); |
| 48 | } |
| 49 | |
| 50 | static int x3proto_gpio_to_irq(struct gpio_chip *chip, unsigned gpio) |
| 51 | { |
| 52 | return x3proto_gpio_irq_map[gpio]; |
| 53 | } |
| 54 | |
| 55 | static void x3proto_gpio_irq_handler(unsigned int irq, struct irq_desc *desc) |
| 56 | { |
| 57 | struct irq_chip *chip = get_irq_desc_chip(desc); |
| 58 | unsigned long mask; |
| 59 | int pin; |
| 60 | |
| 61 | chip->mask_ack(irq); |
| 62 | |
| 63 | mask = __raw_readw(KEYDETR); |
| 64 | |
| 65 | for_each_set_bit(pin, &mask, NR_BASEBOARD_GPIOS) |
| 66 | generic_handle_irq(x3proto_gpio_to_irq(NULL, pin)); |
| 67 | |
| 68 | chip->unmask(irq); |
| 69 | } |
| 70 | |
| 71 | struct gpio_chip x3proto_gpio_chip = { |
| 72 | .label = "x3proto-gpio", |
| 73 | .direction_input = x3proto_gpio_direction_input, |
| 74 | .get = x3proto_gpio_get, |
| 75 | .to_irq = x3proto_gpio_to_irq, |
| 76 | .base = -1, |
| 77 | .ngpio = NR_BASEBOARD_GPIOS, |
| 78 | }; |
| 79 | |
| 80 | int __init x3proto_gpio_setup(void) |
| 81 | { |
| 82 | unsigned int ilsel; |
| 83 | int ret, i; |
| 84 | |
| 85 | ilsel = ilsel_enable(ILSEL_KEY); |
| 86 | if (unlikely(ilsel < 0)) |
| 87 | return ilsel; |
| 88 | |
| 89 | ret = gpiochip_add(&x3proto_gpio_chip); |
| 90 | if (unlikely(ret)) |
| 91 | goto err_gpio; |
| 92 | |
| 93 | for (i = 0; i < NR_BASEBOARD_GPIOS; i++) { |
| 94 | unsigned long flags; |
| 95 | unsigned int irq = create_irq(); |
| 96 | |
| 97 | if (unlikely(irq < 0)) { |
| 98 | ret = -EINVAL; |
| 99 | goto err_irq; |
| 100 | } |
| 101 | |
| 102 | spin_lock_irqsave(&x3proto_gpio_lock, flags); |
| 103 | x3proto_gpio_irq_map[i] = irq; |
| 104 | set_irq_chip_and_handler_name(irq, &dummy_irq_chip, |
| 105 | handle_simple_irq, "gpio"); |
| 106 | spin_unlock_irqrestore(&x3proto_gpio_lock, flags); |
| 107 | } |
| 108 | |
| 109 | pr_info("registering '%s' support, handling GPIOs %u -> %u, " |
| 110 | "bound to IRQ %u\n", |
| 111 | x3proto_gpio_chip.label, x3proto_gpio_chip.base, |
| 112 | x3proto_gpio_chip.base + x3proto_gpio_chip.ngpio, |
| 113 | ilsel); |
| 114 | |
| 115 | set_irq_chained_handler(ilsel, x3proto_gpio_irq_handler); |
| 116 | set_irq_wake(ilsel, 1); |
| 117 | |
| 118 | return 0; |
| 119 | |
| 120 | err_irq: |
| 121 | for (; i >= 0; --i) |
| 122 | if (x3proto_gpio_irq_map[i]) |
| 123 | destroy_irq(x3proto_gpio_irq_map[i]); |
| 124 | |
| 125 | ret = gpiochip_remove(&x3proto_gpio_chip); |
| 126 | if (unlikely(ret)) |
| 127 | pr_err("Failed deregistering GPIO\n"); |
| 128 | |
| 129 | err_gpio: |
| 130 | synchronize_irq(ilsel); |
| 131 | |
| 132 | ilsel_disable(ILSEL_KEY); |
| 133 | |
| 134 | return ret; |
| 135 | } |