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path: root/drivers/gpio/gpio-loongson.c
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Diffstat (limited to 'drivers/gpio/gpio-loongson.c')
-rw-r--r--drivers/gpio/gpio-loongson.c115
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-loongson.c b/drivers/gpio/gpio-loongson.c
new file mode 100644
index 000000000000..ccc65a1aea88
--- /dev/null
+++ b/drivers/gpio/gpio-loongson.c
@@ -0,0 +1,115 @@
+/*
+ * Loongson-2F/3A/3B GPIO Support
+ *
+ * Copyright (c) 2008 Richard Liu, STMicroelectronics <richard.liu@st.com>
+ * Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com>
+ * Copyright (c) 2013 Hongbing Hu <huhb@lemote.com>
+ * Copyright (c) 2014 Huacai Chen <chenhc@lemote.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/err.h>
+#include <asm/types.h>
+#include <loongson.h>
+#include <linux/gpio.h>
+
+#define STLS2F_N_GPIO 4
+#define STLS3A_N_GPIO 16
+
+#ifdef CONFIG_CPU_LOONGSON3
+#define LOONGSON_N_GPIO STLS3A_N_GPIO
+#else
+#define LOONGSON_N_GPIO STLS2F_N_GPIO
+#endif
+
+#define LOONGSON_GPIO_IN_OFFSET 16
+
+static DEFINE_SPINLOCK(gpio_lock);
+
+static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+ u32 temp;
+ u32 mask;
+
+ spin_lock(&gpio_lock);
+ mask = 1 << gpio;
+ temp = LOONGSON_GPIOIE;
+ temp |= mask;
+ LOONGSON_GPIOIE = temp;
+ spin_unlock(&gpio_lock);
+
+ return 0;
+}
+
+static int loongson_gpio_direction_output(struct gpio_chip *chip,
+ unsigned gpio, int level)
+{
+ u32 temp;
+ u32 mask;
+
+ gpio_set_value(gpio, level);
+ spin_lock(&gpio_lock);
+ mask = 1 << gpio;
+ temp = LOONGSON_GPIOIE;
+ temp &= (~mask);
+ LOONGSON_GPIOIE = temp;
+ spin_unlock(&gpio_lock);
+
+ return 0;
+}
+
+static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+ u32 val;
+ u32 mask;
+
+ mask = 1 << (gpio + LOONGSON_GPIO_IN_OFFSET);
+ spin_lock(&gpio_lock);
+ val = LOONGSON_GPIODATA;
+ spin_unlock(&gpio_lock);
+
+ return (val & mask) != 0;
+}
+
+static void loongson_gpio_set_value(struct gpio_chip *chip,
+ unsigned gpio, int value)
+{
+ u32 val;
+ u32 mask;
+
+ mask = 1 << gpio;
+
+ spin_lock(&gpio_lock);
+ val = LOONGSON_GPIODATA;
+ if (value)
+ val |= mask;
+ else
+ val &= (~mask);
+ LOONGSON_GPIODATA = val;
+ spin_unlock(&gpio_lock);
+}
+
+static struct gpio_chip loongson_chip = {
+ .label = "Loongson-gpio-chip",
+ .direction_input = loongson_gpio_direction_input,
+ .get = loongson_gpio_get_value,
+ .direction_output = loongson_gpio_direction_output,
+ .set = loongson_gpio_set_value,
+ .base = 0,
+ .ngpio = LOONGSON_N_GPIO,
+ .can_sleep = false,
+};
+
+static int __init loongson_gpio_setup(void)
+{
+ return gpiochip_add(&loongson_chip);
+}
+postcore_initcall(loongson_gpio_setup);