[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>

3 files changed, 273 insertions, 0 deletions

diff --git a/arch/arm/plat-orion/Makefile b/arch/arm/plat-orion/Makefile
index 198f3dd..56021a7 100644
--- a/arch/arm/plat-orion/Makefile
+++ b/arch/arm/plat-orion/Makefile
@@ -6,3 +6,5 @@ obj-y	:= irq.o pcie.o time.o
 obj-m	:=
 obj-n	:=
 obj-	:=
+
+obj-$(CONFIG_GENERIC_GPIO) += gpio.o
diff --git a/arch/arm/plat-orion/gpio.c b/arch/arm/plat-orion/gpio.c
new file mode 100644
index 0000000..d86fc08
--- /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);
diff --git a/arch/arm/plat-orion/include/plat/gpio.h b/arch/arm/plat-orion/include/plat/gpio.h
new file mode 100644
index 0000000..956658d
--- /dev/null
+++ b/arch/arm/plat-orion/include/plat/gpio.h
@@ -0,0 +1,32 @@
+/*
+ * arch/arm/plat-orion/include/plat/gpio.h
+ *
+ * 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.
+ */
+
+#ifndef __PLAT_GPIO_H
+#define __PLAT_GPIO_H
+
+/*
+ * GENERIC_GPIO primitives.
+ */
+int gpio_request(unsigned pin, const char *label);
+void gpio_free(unsigned pin);
+int gpio_direction_input(unsigned pin);
+int gpio_direction_output(unsigned pin, int value);
+int gpio_get_value(unsigned pin);
+void gpio_set_value(unsigned pin, int value);
+
+/*
+ * Orion-specific GPIO API extensions.
+ */
+void orion_gpio_set_unused(unsigned pin);
+void orion_gpio_set_valid(unsigned pin, int valid);
+void orion_gpio_set_blink(unsigned pin, int blink);
+
+
+#endif