aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-s3c/gpio.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/plat-s3c/gpio.c')
-rw-r--r--arch/arm/plat-s3c/gpio.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c/gpio.c b/arch/arm/plat-s3c/gpio.c
new file mode 100644
index 0000000..d71dd6d
--- /dev/null
+++ b/arch/arm/plat-s3c/gpio.c
@@ -0,0 +1,147 @@
+/* linux/arch/arm/plat-s3c/gpio.c
+ *
+ * Copyright 2008 Simtec Electronics
+ * Ben Dooks <ben@simtec.co.uk>
+ * http://armlinux.simtec.co.uk/
+ *
+ * S3C series GPIO core
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+
+#include <plat/gpio-core.h>
+
+#ifdef CONFIG_S3C_GPIO_TRACK
+struct s3c_gpio_chip *s3c_gpios[S3C_GPIO_END];
+
+static __init void s3c_gpiolib_track(struct s3c_gpio_chip *chip)
+{
+ unsigned int gpn;
+ int i;
+
+ gpn = chip->chip.base;
+ for (i = 0; i < chip->chip.ngpio; i++, gpn++) {
+ BUG_ON(gpn > ARRAY_SIZE(s3c_gpios));
+ s3c_gpios[gpn] = chip;
+ }
+}
+#endif /* CONFIG_S3C_GPIO_TRACK */
+
+/* Default routines for controlling GPIO, based on the original S3C24XX
+ * GPIO functions which deal with the case where each gpio bank of the
+ * chip is as following:
+ *
+ * base + 0x00: Control register, 2 bits per gpio
+ * gpio n: 2 bits starting at (2*n)
+ * 00 = input, 01 = output, others mean special-function
+ * base + 0x04: Data register, 1 bit per gpio
+ * bit n: data bit n
+*/
+
+static int s3c_gpiolib_input(struct gpio_chip *chip, unsigned offset)
+{
+ struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+ void __iomem *base = ourchip->base;
+ unsigned long flags;
+ unsigned long con;
+
+ local_irq_save(flags);
+
+ con = __raw_readl(base + 0x00);
+ con &= ~(3 << (offset * 2));
+
+ __raw_writel(con, base + 0x00);
+
+ local_irq_restore(flags);
+ return 0;
+}
+
+static int s3c_gpiolib_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+ void __iomem *base = ourchip->base;
+ unsigned long flags;
+ unsigned long dat;
+ unsigned long con;
+
+ local_irq_save(flags);
+
+ dat = __raw_readl(base + 0x04);
+ dat &= ~(1 << offset);
+ if (value)
+ dat |= 1 << offset;
+ __raw_writel(dat, base + 0x04);
+
+ con = __raw_readl(base + 0x00);
+ con &= ~(3 << (offset * 2));
+ con |= 1 << (offset * 2);
+
+ __raw_writel(con, base + 0x00);
+ __raw_writel(dat, base + 0x04);
+
+ local_irq_restore(flags);
+ return 0;
+}
+
+static void s3c_gpiolib_set(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+ void __iomem *base = ourchip->base;
+ unsigned long flags;
+ unsigned long dat;
+
+ local_irq_save(flags);
+
+ dat = __raw_readl(base + 0x04);
+ dat &= ~(1 << offset);
+ if (value)
+ dat |= 1 << offset;
+ __raw_writel(dat, base + 0x04);
+
+ local_irq_restore(flags);
+}
+
+static int s3c_gpiolib_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+ unsigned long val;
+
+ val = __raw_readl(ourchip->base + 0x04);
+ val >>= offset;
+ val &= 1;
+
+ return val;
+}
+
+__init void s3c_gpiolib_add(struct s3c_gpio_chip *chip)
+{
+ struct gpio_chip *gc = &chip->chip;
+ int ret;
+
+ BUG_ON(!chip->base);
+ BUG_ON(!gc->label);
+ BUG_ON(!gc->ngpio);
+
+ if (!gc->direction_input)
+ gc->direction_input = s3c_gpiolib_input;
+ if (!gc->direction_output)
+ gc->direction_output = s3c_gpiolib_output;
+ if (!gc->set)
+ gc->set = s3c_gpiolib_set;
+ if (!gc->get)
+ gc->get = s3c_gpiolib_get;
+
+ /* gpiochip_add() prints own failure message on error. */
+ ret = gpiochip_add(gc);
+ if (ret >= 0)
+ s3c_gpiolib_track(chip);
+}