| 1 | /* |
| 2 | * Loongson-2F/3A/3B GPIO Support |
| 3 | * |
| 4 | * Copyright (c) 2008 Richard Liu, STMicroelectronics <richard.liu@st.com> |
| 5 | * Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com> |
| 6 | * Copyright (c) 2013 Hongbing Hu <huhb@lemote.com> |
| 7 | * Copyright (c) 2014 Huacai Chen <chenhc@lemote.com> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/spinlock.h> |
| 19 | #include <linux/err.h> |
| 20 | #include <asm/types.h> |
| 21 | #include <loongson.h> |
| 22 | #include <linux/gpio.h> |
| 23 | |
| 24 | #define STLS2F_N_GPIO 4 |
| 25 | #define STLS3A_N_GPIO 16 |
| 26 | |
| 27 | #ifdef CONFIG_CPU_LOONGSON3 |
| 28 | #define LOONGSON_N_GPIO STLS3A_N_GPIO |
| 29 | #else |
| 30 | #define LOONGSON_N_GPIO STLS2F_N_GPIO |
| 31 | #endif |
| 32 | |
| 33 | #define LOONGSON_GPIO_IN_OFFSET 16 |
| 34 | |
| 35 | static DEFINE_SPINLOCK(gpio_lock); |
| 36 | |
| 37 | static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) |
| 38 | { |
| 39 | u32 temp; |
| 40 | u32 mask; |
| 41 | |
| 42 | spin_lock(&gpio_lock); |
| 43 | mask = 1 << gpio; |
| 44 | temp = LOONGSON_GPIOIE; |
| 45 | temp |= mask; |
| 46 | LOONGSON_GPIOIE = temp; |
| 47 | spin_unlock(&gpio_lock); |
| 48 | |
| 49 | return 0; |
| 50 | } |
| 51 | |
| 52 | static int loongson_gpio_direction_output(struct gpio_chip *chip, |
| 53 | unsigned gpio, int level) |
| 54 | { |
| 55 | u32 temp; |
| 56 | u32 mask; |
| 57 | |
| 58 | gpio_set_value(gpio, level); |
| 59 | spin_lock(&gpio_lock); |
| 60 | mask = 1 << gpio; |
| 61 | temp = LOONGSON_GPIOIE; |
| 62 | temp &= (~mask); |
| 63 | LOONGSON_GPIOIE = temp; |
| 64 | spin_unlock(&gpio_lock); |
| 65 | |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio) |
| 70 | { |
| 71 | u32 val; |
| 72 | u32 mask; |
| 73 | |
| 74 | mask = 1 << (gpio + LOONGSON_GPIO_IN_OFFSET); |
| 75 | spin_lock(&gpio_lock); |
| 76 | val = LOONGSON_GPIODATA; |
| 77 | spin_unlock(&gpio_lock); |
| 78 | |
| 79 | return (val & mask) != 0; |
| 80 | } |
| 81 | |
| 82 | static void loongson_gpio_set_value(struct gpio_chip *chip, |
| 83 | unsigned gpio, int value) |
| 84 | { |
| 85 | u32 val; |
| 86 | u32 mask; |
| 87 | |
| 88 | mask = 1 << gpio; |
| 89 | |
| 90 | spin_lock(&gpio_lock); |
| 91 | val = LOONGSON_GPIODATA; |
| 92 | if (value) |
| 93 | val |= mask; |
| 94 | else |
| 95 | val &= (~mask); |
| 96 | LOONGSON_GPIODATA = val; |
| 97 | spin_unlock(&gpio_lock); |
| 98 | } |
| 99 | |
| 100 | static struct gpio_chip loongson_chip = { |
| 101 | .label = "Loongson-gpio-chip", |
| 102 | .direction_input = loongson_gpio_direction_input, |
| 103 | .get = loongson_gpio_get_value, |
| 104 | .direction_output = loongson_gpio_direction_output, |
| 105 | .set = loongson_gpio_set_value, |
| 106 | .base = 0, |
| 107 | .ngpio = LOONGSON_N_GPIO, |
| 108 | .can_sleep = false, |
| 109 | }; |
| 110 | |
| 111 | static int __init loongson_gpio_setup(void) |
| 112 | { |
| 113 | return gpiochip_add(&loongson_chip); |
| 114 | } |
| 115 | postcore_initcall(loongson_gpio_setup); |