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authorLennert Buytenhek <buytenh@wantstofly.org>2008-10-20 03:51:03 +0400
committerNicolas Pitre <nico@cam.org>2008-12-20 20:21:02 +0300
commit9569dae75f6f6987e79fa26cf6da3fc24006c996 (patch)
treeb5982f41aea6ccee37af54fc8f7750aaff7e0bff /arch/arm/plat-orion/gpio.c
parent6fd7c7fe72a46dfd227fe8db0c7b6863af90a982 (diff)
downloadlinux-9569dae75f6f6987e79fa26cf6da3fc24006c996.tar.xz
[ARM] Orion: share GPIO handling code
Split off Orion GPIO handling code into plat-orion/, and add support for multiple sets of (32) GPIO pins. Signed-off-by: Lennert Buytenhek <buytenh@marvell.com> Signed-off-by: Nicolas Pitre <nico@marvell.com>
Diffstat (limited to 'arch/arm/plat-orion/gpio.c')
-rw-r--r--arch/arm/plat-orion/gpio.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c
new file mode 100644
index 000000000000..d86fc085e489
--- /dev/null
+++ b/arch/arm/plat-orion/gpio.c
@@ -0,0 +1,239 @@
+/*
+ * arch/arm/plat-orion/gpio.c
+ *
+ * Marvell Orion SoC GPIO handling.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <asm/gpio.h>
+
+static DEFINE_SPINLOCK(gpio_lock);
+static const char *gpio_label[GPIO_MAX]; /* non null for allocated GPIOs */
+static unsigned long gpio_valid[BITS_TO_LONGS(GPIO_MAX)];
+
+static inline void __set_direction(unsigned pin, int input)
+{
+ u32 u;
+
+ u = readl(GPIO_IO_CONF(pin));
+ if (input)
+ u |= 1 << (pin & 31);
+ else
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_IO_CONF(pin));
+}
+
+static void __set_level(unsigned pin, int high)
+{
+ u32 u;
+
+ u = readl(GPIO_OUT(pin));
+ if (high)
+ u |= 1 << (pin & 31);
+ else
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_OUT(pin));
+}
+
+
+/*
+ * GENERIC_GPIO primitives.
+ */
+int gpio_direction_input(unsigned pin)
+{
+ unsigned long flags;
+
+ if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
+ pr_debug("%s: invalid GPIO %d\n", __func__, pin);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ /*
+ * Some callers might not have used gpio_request(),
+ * so flag this pin as requested now.
+ */
+ if (gpio_label[pin] == NULL)
+ gpio_label[pin] = "?";
+
+ /*
+ * Configure GPIO direction.
+ */
+ __set_direction(pin, 1);
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(gpio_direction_input);
+
+int gpio_direction_output(unsigned pin, int value)
+{
+ unsigned long flags;
+ u32 u;
+
+ if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
+ pr_debug("%s: invalid GPIO %d\n", __func__, pin);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ /*
+ * Some callers might not have used gpio_request(),
+ * so flag this pin as requested now.
+ */
+ if (gpio_label[pin] == NULL)
+ gpio_label[pin] = "?";
+
+ /*
+ * Disable blinking.
+ */
+ u = readl(GPIO_BLINK_EN(pin));
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_BLINK_EN(pin));
+
+ /*
+ * Configure GPIO output value.
+ */
+ __set_level(pin, value);
+
+ /*
+ * Configure GPIO direction.
+ */
+ __set_direction(pin, 0);
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(gpio_direction_output);
+
+int gpio_get_value(unsigned pin)
+{
+ int val;
+
+ if (readl(GPIO_IO_CONF(pin)) & (1 << (pin & 31)))
+ val = readl(GPIO_DATA_IN(pin)) ^ readl(GPIO_IN_POL(pin));
+ else
+ val = readl(GPIO_OUT(pin));
+
+ return (val >> (pin & 31)) & 1;
+}
+EXPORT_SYMBOL(gpio_get_value);
+
+void gpio_set_value(unsigned pin, int value)
+{
+ unsigned long flags;
+ u32 u;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ /*
+ * Disable blinking.
+ */
+ u = readl(GPIO_BLINK_EN(pin));
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_BLINK_EN(pin));
+
+ /*
+ * Configure GPIO output value.
+ */
+ __set_level(pin, value);
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+}
+EXPORT_SYMBOL(gpio_set_value);
+
+int gpio_request(unsigned pin, const char *label)
+{
+ unsigned long flags;
+ int ret;
+
+ if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
+ pr_debug("%s: invalid GPIO %d\n", __func__, pin);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&gpio_lock, flags);
+ if (gpio_label[pin] == NULL) {
+ gpio_label[pin] = label ? label : "?";
+ ret = 0;
+ } else {
+ pr_debug("%s: GPIO %d already used as %s\n",
+ __func__, pin, gpio_label[pin]);
+ ret = -EBUSY;
+ }
+ spin_unlock_irqrestore(&gpio_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(gpio_request);
+
+void gpio_free(unsigned pin)
+{
+ if (pin >= GPIO_MAX || !test_bit(pin, gpio_valid)) {
+ pr_debug("%s: invalid GPIO %d\n", __func__, pin);
+ return;
+ }
+
+ if (gpio_label[pin] == NULL)
+ pr_warning("%s: GPIO %d already freed\n", __func__, pin);
+ else
+ gpio_label[pin] = NULL;
+}
+EXPORT_SYMBOL(gpio_free);
+
+
+/*
+ * Orion-specific GPIO API extensions.
+ */
+void __init orion_gpio_set_unused(unsigned pin)
+{
+ /*
+ * Configure as output, drive low.
+ */
+ __set_level(pin, 0);
+ __set_direction(pin, 0);
+}
+
+void __init orion_gpio_set_valid(unsigned pin, int valid)
+{
+ if (valid)
+ __set_bit(pin, gpio_valid);
+ else
+ __clear_bit(pin, gpio_valid);
+}
+
+void orion_gpio_set_blink(unsigned pin, int blink)
+{
+ unsigned long flags;
+ u32 u;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ /*
+ * Set output value to zero.
+ */
+ __set_level(pin, 0);
+
+ u = readl(GPIO_BLINK_EN(pin));
+ if (blink)
+ u |= 1 << (pin & 31);
+ else
+ u &= ~(1 << (pin & 31));
+ writel(u, GPIO_BLINK_EN(pin));
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+}
+EXPORT_SYMBOL(orion_gpio_set_blink);