1 files changed, 253 insertions, 0 deletions
diff --git a/arch/arm/plat-mxc/gpio.c b/arch/arm/plat-mxc/gpio.c
new file mode 100644
index 00000000000..4a7736717d8
--- /dev/null
+++ b/arch/arm/plat-mxc/gpio.c
@@ -0,0 +1,253 @@
+/*
+ * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
+ * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
+ *
+ * Based on code from Freescale,
+ * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * 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.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <asm/hardware.h>
+#include <asm-generic/bug.h>
+
+static struct mxc_gpio_port *mxc_gpio_ports;
+static int gpio_table_size;
+
+/* Note: This driver assumes 32 GPIOs are handled in one register */
+
+static void _clear_gpio_irqstatus(struct mxc_gpio_port *port, u32 index)
+{
+	__raw_writel(1 << index, port->base + GPIO_ISR);
+}
+
+static void _set_gpio_irqenable(struct mxc_gpio_port *port, u32 index,
+				int enable)
+{
+	u32 l;
+
+	l = __raw_readl(port->base + GPIO_IMR);
+	l = (l & (~(1 << index))) | (!!enable << index);
+	__raw_writel(l, port->base + GPIO_IMR);
+}
+
+static void gpio_ack_irq(u32 irq)
+{
+	u32 gpio = irq_to_gpio(irq);
+	_clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f);
+}
+
+static void gpio_mask_irq(u32 irq)
+{
+	u32 gpio = irq_to_gpio(irq);
+	_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0);
+}
+
+static void gpio_unmask_irq(u32 irq)
+{
+	u32 gpio = irq_to_gpio(irq);
+	_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1);
+}
+
+static int gpio_set_irq_type(u32 irq, u32 type)
+{
+	u32 gpio = irq_to_gpio(irq);
+	struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
+	u32 bit, val;
+	int edge;
+	void __iomem *reg = port->base;
+
+	switch (type) {
+	case IRQT_RISING:
+		edge = GPIO_INT_RISE_EDGE;
+		break;
+	case IRQT_FALLING:
+		edge = GPIO_INT_FALL_EDGE;
+		break;
+	case IRQT_LOW:
+		edge = GPIO_INT_LOW_LEV;
+		break;
+	case IRQT_HIGH:
+		edge = GPIO_INT_HIGH_LEV;
+		break;
+	default:	/* this includes IRQT_BOTHEDGE */
+		return -EINVAL;
+	}
+
+	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
+	bit = gpio & 0xf;
+	val = __raw_readl(reg) & ~(0x3 << (bit << 1));
+	__raw_writel(val | (edge << (bit << 1)), reg);
+	_clear_gpio_irqstatus(port, gpio & 0x1f);
+
+	return 0;
+}
+
+/* handle n interrupts in one status register */
+static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
+{
+	u32 gpio_irq_no;
+
+	gpio_irq_no = port->virtual_irq_start;
+	for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {
+
+		if ((irq_stat & 1) == 0)
+			continue;
+
+		BUG_ON(!(irq_desc[gpio_irq_no].handle_irq));
+		irq_desc[gpio_irq_no].handle_irq(gpio_irq_no,
+				&irq_desc[gpio_irq_no]);
+	}
+}
+
+#ifdef CONFIG_ARCH_MX3
+/* MX3 has one interrupt *per* gpio port */
+static void mx3_gpio_irq_handler(u32 irq, struct irq_desc *desc)
+{
+	u32 irq_stat;
+	struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq);
+
+	irq_stat = __raw_readl(port->base + GPIO_ISR) &
+			__raw_readl(port->base + GPIO_IMR);
+	BUG_ON(!irq_stat);
+	mxc_gpio_irq_handler(port, irq_stat);
+}
+#endif
+
+#ifdef CONFIG_ARCH_MX2
+/* MX2 has one interrupt *for all* gpio ports */
+static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc)
+{
+	int i;
+	u32 irq_msk, irq_stat;
+	struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq);
+
+	/* walk through all interrupt status registers */
+	for (i = 0; i < gpio_table_size; i++) {
+		irq_msk = __raw_readl(port[i].base + GPIO_IMR);
+		if (!irq_msk)
+			continue;
+
+		irq_stat = __raw_readl(port[i].base + GPIO_ISR) & irq_msk;
+		if (irq_stat)
+			mxc_gpio_irq_handler(&port[i], irq_stat);
+	}
+}
+#endif
+
+static struct irq_chip gpio_irq_chip = {
+	.ack = gpio_ack_irq,
+	.mask = gpio_mask_irq,
+	.unmask = gpio_unmask_irq,
+	.set_type = gpio_set_irq_type,
+};
+
+static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset,
+				int dir)
+{
+	struct mxc_gpio_port *port =
+		container_of(chip, struct mxc_gpio_port, chip);
+	u32 l;
+
+	l = __raw_readl(port->base + GPIO_GDIR);
+	if (dir)
+		l |= 1 << offset;
+	else
+		l &= ~(1 << offset);
+	__raw_writel(l, port->base + GPIO_GDIR);
+}
+
+static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct mxc_gpio_port *port =
+		container_of(chip, struct mxc_gpio_port, chip);
+	void __iomem *reg = port->base + GPIO_DR;
+	u32 l;
+
+	l = (__raw_readl(reg) & (~(1 << offset))) | (value << offset);
+	__raw_writel(l, reg);
+}
+
+static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct mxc_gpio_port *port =
+		container_of(chip, struct mxc_gpio_port, chip);
+
+	return (__raw_readl(port->base + GPIO_DR) >> offset) & 1;
+}
+
+static int mxc_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	_set_gpio_direction(chip, offset, 0);
+	return 0;
+}
+
+static int mxc_gpio_direction_output(struct gpio_chip *chip,
+				     unsigned offset, int value)
+{
+	_set_gpio_direction(chip, offset, 1);
+	mxc_gpio_set(chip, offset, value);
+	return 0;
+}
+
+int __init mxc_gpio_init(struct mxc_gpio_port *port, int cnt)
+{
+	int i, j;
+
+	/* save for local usage */
+	mxc_gpio_ports = port;
+	gpio_table_size = cnt;
+
+	printk(KERN_INFO "MXC GPIO hardware\n");
+
+	for (i = 0; i < cnt; i++) {
+		/* disable the interrupt and clear the status */
+		__raw_writel(0, port[i].base + GPIO_IMR);
+		__raw_writel(~0, port[i].base + GPIO_ISR);
+		for (j = port[i].virtual_irq_start;
+			j < port[i].virtual_irq_start + 32; j++) {
+			set_irq_chip(j, &gpio_irq_chip);
+			set_irq_handler(j, handle_edge_irq);
+			set_irq_flags(j, IRQF_VALID);
+		}
+
+		/* register gpio chip */
+		port[i].chip.direction_input = mxc_gpio_direction_input;
+		port[i].chip.direction_output = mxc_gpio_direction_output;
+		port[i].chip.get = mxc_gpio_get;
+		port[i].chip.set = mxc_gpio_set;
+		port[i].chip.base = i * 32;
+		port[i].chip.ngpio = 32;
+
+		/* its a serious configuration bug when it fails */
+		BUG_ON( gpiochip_add(&port[i].chip) < 0 );
+
+#ifdef CONFIG_ARCH_MX3
+		/* setup one handler for each entry */
+		set_irq_chained_handler(port[i].irq, mx3_gpio_irq_handler);
+		set_irq_data(port[i].irq, &port[i]);
+#endif
+	}
+
+#ifdef CONFIG_ARCH_MX2
+	/* setup one handler for all GPIO interrupts */
+	set_irq_chained_handler(port[0].irq, mx2_gpio_irq_handler);
+	set_irq_data(port[0].irq, port);
+#endif
+	return 0;
+}