[PATCH v3 1/5] gpio: gpio-mxc: copy plat-mxc/gpio.c into drivers/gpio

[Shawn Guo]

As the first patch of the series that moves plat-mxc gpio driver into
drivers/gpio, it copies arch/arm/plat-mxc/gpio.c into
drivers/gpio/gpio-mxc.c.  The later patches will make necessary
changes to the driver, migrate the existing users to it, and lastly
deletes plat-mxc gpio driver.

Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
---
 drivers/gpio/gpio-mxc.c |  361 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 361 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/gpio-mxc.c

diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
new file mode 100644
index 0000000..6cd6d7f
--- /dev/null
+++ b/drivers/gpio/gpio-mxc.c
@@ -0,0 +1,361 @@
+/*
+ * MXC GPIO support. (c) 2008 Daniel Mack <daniel@xxxxxxxx>
+ * Copyright 2008 Juergen Beisert, kernel@xxxxxxxxxxxxxx
+ *
+ * Based on code from Freescale,
+ * Copyright (C) 2004-2010 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/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <mach/hardware.h>
+#include <asm-generic/bug.h>
+
+static struct mxc_gpio_port *mxc_gpio_ports;
+static int gpio_table_size;
+
+#define cpu_is_mx1_mx2()	(cpu_is_mx1() || cpu_is_mx2())
+
+#define GPIO_DR		(cpu_is_mx1_mx2() ? 0x1c : 0x00)
+#define GPIO_GDIR	(cpu_is_mx1_mx2() ? 0x00 : 0x04)
+#define GPIO_PSR	(cpu_is_mx1_mx2() ? 0x24 : 0x08)
+#define GPIO_ICR1	(cpu_is_mx1_mx2() ? 0x28 : 0x0C)
+#define GPIO_ICR2	(cpu_is_mx1_mx2() ? 0x2C : 0x10)
+#define GPIO_IMR	(cpu_is_mx1_mx2() ? 0x30 : 0x14)
+#define GPIO_ISR	(cpu_is_mx1_mx2() ? 0x34 : 0x18)
+
+#define GPIO_INT_LOW_LEV	(cpu_is_mx1_mx2() ? 0x3 : 0x0)
+#define GPIO_INT_HIGH_LEV	(cpu_is_mx1_mx2() ? 0x2 : 0x1)
+#define GPIO_INT_RISE_EDGE	(cpu_is_mx1_mx2() ? 0x0 : 0x2)
+#define GPIO_INT_FALL_EDGE	(cpu_is_mx1_mx2() ? 0x1 : 0x3)
+#define GPIO_INT_NONE		0x4
+
+/* 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(struct irq_data *d)
+{
+	u32 gpio = irq_to_gpio(d->irq);
+	_clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f);
+}
+
+static void gpio_mask_irq(struct irq_data *d)
+{
+	u32 gpio = irq_to_gpio(d->irq);
+	_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0);
+}
+
+static void gpio_unmask_irq(struct irq_data *d)
+{
+	u32 gpio = irq_to_gpio(d->irq);
+	_set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1);
+}
+
+static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset);
+
+static int gpio_set_irq_type(struct irq_data *d, u32 type)
+{
+	u32 gpio = irq_to_gpio(d->irq);
+	struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
+	u32 bit, val;
+	int edge;
+	void __iomem *reg = port->base;
+
+	port->both_edges &= ~(1 << (gpio & 31));
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		edge = GPIO_INT_RISE_EDGE;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		edge = GPIO_INT_FALL_EDGE;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		val = mxc_gpio_get(&port->chip, gpio & 31);
+		if (val) {
+			edge = GPIO_INT_LOW_LEV;
+			pr_debug("mxc: set GPIO %d to low trigger\n", gpio);
+		} else {
+			edge = GPIO_INT_HIGH_LEV;
+			pr_debug("mxc: set GPIO %d to high trigger\n", gpio);
+		}
+		port->both_edges |= 1 << (gpio & 31);
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		edge = GPIO_INT_LOW_LEV;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		edge = GPIO_INT_HIGH_LEV;
+		break;
+	default:
+		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;
+}
+
+static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
+{
+	void __iomem *reg = port->base;
+	u32 bit, val;
+	int edge;
+
+	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
+	bit = gpio & 0xf;
+	val = __raw_readl(reg);
+	edge = (val >> (bit << 1)) & 3;
+	val &= ~(0x3 << (bit << 1));
+	if (edge == GPIO_INT_HIGH_LEV) {
+		edge = GPIO_INT_LOW_LEV;
+		pr_debug("mxc: switch GPIO %d to low trigger\n", gpio);
+	} else if (edge == GPIO_INT_LOW_LEV) {
+		edge = GPIO_INT_HIGH_LEV;
+		pr_debug("mxc: switch GPIO %d to high trigger\n", gpio);
+	} else {
+		pr_err("mxc: invalid configuration for GPIO %d: %x\n",
+		       gpio, edge);
+		return;
+	}
+	__raw_writel(val | (edge << (bit << 1)), reg);
+}
+
+/* handle 32 interrupts in one status register */
+static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
+{
+	u32 gpio_irq_no_base = port->virtual_irq_start;
+
+	while (irq_stat != 0) {
+		int irqoffset = fls(irq_stat) - 1;
+
+		if (port->both_edges & (1 << irqoffset))
+			mxc_flip_edge(port, irqoffset);
+
+		generic_handle_irq(gpio_irq_no_base + irqoffset);
+
+		irq_stat &= ~(1 << irqoffset);
+	}
+}
+
+/* MX1 and 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 = irq_get_handler_data(irq);
+
+	irq_stat = __raw_readl(port->base + GPIO_ISR) &
+			__raw_readl(port->base + GPIO_IMR);
+
+	mxc_gpio_irq_handler(port, irq_stat);
+}
+
+/* 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 = irq_get_handler_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);
+	}
+}
+
+/*
+ * Set interrupt number "irq" in the GPIO as a wake-up source.
+ * While system is running, all registered GPIO interrupts need to have
+ * wake-up enabled. When system is suspended, only selected GPIO interrupts
+ * need to have wake-up enabled.
+ * @param  irq          interrupt source number
+ * @param  enable       enable as wake-up if equal to non-zero
+ * @return       This function returns 0 on success.
+ */
+static int gpio_set_wake_irq(struct irq_data *d, u32 enable)
+{
+	u32 gpio = irq_to_gpio(d->irq);
+	u32 gpio_idx = gpio & 0x1F;
+	struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32];
+
+	if (enable) {
+		if (port->irq_high && (gpio_idx >= 16))
+			enable_irq_wake(port->irq_high);
+		else
+			enable_irq_wake(port->irq);
+	} else {
+		if (port->irq_high && (gpio_idx >= 16))
+			disable_irq_wake(port->irq_high);
+		else
+			disable_irq_wake(port->irq);
+	}
+
+	return 0;
+}
+
+static struct irq_chip gpio_irq_chip = {
+	.name = "GPIO",
+	.irq_ack = gpio_ack_irq,
+	.irq_mask = gpio_mask_irq,
+	.irq_unmask = gpio_unmask_irq,
+	.irq_set_type = gpio_set_irq_type,
+	.irq_set_wake = gpio_set_wake_irq,
+};
+
+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;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	l = __raw_readl(port->base + GPIO_GDIR);
+	if (dir)
+		l |= 1 << offset;
+	else
+		l &= ~(1 << offset);
+	__raw_writel(l, port->base + GPIO_GDIR);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+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;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	l = (__raw_readl(reg) & (~(1 << offset))) | (!!value << offset);
+	__raw_writel(l, reg);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+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_PSR) >> 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)
+{
+	mxc_gpio_set(chip, offset, value);
+	_set_gpio_direction(chip, offset, 1);
+	return 0;
+}
+
+/*
+ * This lock class tells lockdep that GPIO irqs are in a different
+ * category than their parents, so it won't report false recursion.
+ */
+static struct lock_class_key gpio_lock_class;
+
+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++) {
+			irq_set_lockdep_class(j, &gpio_lock_class);
+			irq_set_chip_and_handler(j, &gpio_irq_chip,
+						 handle_level_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;
+
+		spin_lock_init(&port[i].lock);
+
+		/* its a serious configuration bug when it fails */
+		BUG_ON( gpiochip_add(&port[i].chip) < 0 );
+
+		if (cpu_is_mx1() || cpu_is_mx3() || cpu_is_mx25() || cpu_is_mx51()) {
+			/* setup one handler for each entry */
+			irq_set_chained_handler(port[i].irq,
+						mx3_gpio_irq_handler);
+			irq_set_handler_data(port[i].irq, &port[i]);
+			if (port[i].irq_high) {
+				/* setup handler for GPIO 16 to 31 */
+				irq_set_chained_handler(port[i].irq_high,
+							mx3_gpio_irq_handler);
+				irq_set_handler_data(port[i].irq_high,
+						     &port[i]);
+			}
+		}
+	}
+
+	if (cpu_is_mx2()) {
+		/* setup one handler for all GPIO interrupts */
+		irq_set_chained_handler(port[0].irq, mx2_gpio_irq_handler);
+		irq_set_handler_data(port[0].irq, port);
+	}
+
+	return 0;
+}
-- 
1.7.4.1

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