[ARM] 4457/2: davinci: GPIO support

Support GPIO driver for TI DaVinci SoC

Signed-off-by: Vladimir Barinov <vbarino@ru.mvista.com>
Acked-by: David Brownell <david-b@pacbell.net>
Acked-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 286 insertions, 0 deletions

diff --git a/arch/arm/mach-davinci/gpio.c b/arch/arm/mach-davinci/gpio.c
new file mode 100644
index 000000000000..9c67886e7189
--- /dev/null
+++ b/arch/arm/mach-davinci/gpio.c
@@ -0,0 +1,286 @@
+/*
+ * TI DaVinci GPIO Support
+ *
+ * Copyright (c) 2006 David Brownell
+ * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
+ *
+ * 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.
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/bitops.h>
+
+#include <asm/arch/irqs.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/gpio.h>
+
+#include <asm/mach/irq.h>
+
+static DEFINE_SPINLOCK(gpio_lock);
+static DECLARE_BITMAP(gpio_in_use, DAVINCI_N_GPIO);
+
+int gpio_request(unsigned gpio, const char *tag)
+{
+	if (gpio >= DAVINCI_N_GPIO)
+		return -EINVAL;
+
+	if (test_and_set_bit(gpio, gpio_in_use))
+		return -EBUSY;
+
+	return 0;
+}
+EXPORT_SYMBOL(gpio_request);
+
+void gpio_free(unsigned gpio)
+{
+	if (gpio >= DAVINCI_N_GPIO)
+		return;
+
+	clear_bit(gpio, gpio_in_use);
+}
+EXPORT_SYMBOL(gpio_free);
+
+/* create a non-inlined version */
+static struct gpio_controller *__iomem gpio2controller(unsigned gpio)
+{
+	return __gpio_to_controller(gpio);
+}
+
+/*
+ * Assuming the pin is muxed as a gpio output, set its output value.
+ */
+void __gpio_set(unsigned gpio, int value)
+{
+	struct gpio_controller *__iomem g = gpio2controller(gpio);
+
+	__raw_writel(__gpio_mask(gpio), value ? &g->set_data : &g->clr_data);
+}
+EXPORT_SYMBOL(__gpio_set);
+
+
+/*
+ * Read the pin's value (works even if it's set up as output);
+ * returns zero/nonzero.
+ *
+ * Note that changes are synched to the GPIO clock, so reading values back
+ * right after you've set them may give old values.
+ */
+int __gpio_get(unsigned gpio)
+{
+	struct gpio_controller *__iomem g = gpio2controller(gpio);
+
+	return !!(__gpio_mask(gpio) & __raw_readl(&g->in_data));
+}
+EXPORT_SYMBOL(__gpio_get);
+
+
+/*--------------------------------------------------------------------------*/
+
+/*
+ * board setup code *MUST* set PINMUX0 and PINMUX1 as
+ * needed, and enable the GPIO clock.
+ */
+
+int gpio_direction_input(unsigned gpio)
+{
+	struct gpio_controller *__iomem g = gpio2controller(gpio);
+	u32 temp;
+	u32 mask;
+
+	if (!g)
+		return -EINVAL;
+
+	spin_lock(&gpio_lock);
+	mask = __gpio_mask(gpio);
+	temp = __raw_readl(&g->dir);
+	temp |= mask;
+	__raw_writel(temp, &g->dir);
+	spin_unlock(&gpio_lock);
+	return 0;
+}
+EXPORT_SYMBOL(gpio_direction_input);
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+	struct gpio_controller *__iomem g = gpio2controller(gpio);
+	u32 temp;
+	u32 mask;
+
+	if (!g)
+		return -EINVAL;
+
+	spin_lock(&gpio_lock);
+	mask = __gpio_mask(gpio);
+	temp = __raw_readl(&g->dir);
+	temp &= ~mask;
+	__raw_writel(mask, value ? &g->set_data : &g->clr_data);
+	__raw_writel(temp, &g->dir);
+	spin_unlock(&gpio_lock);
+	return 0;
+}
+EXPORT_SYMBOL(gpio_direction_output);
+
+/*
+ * We expect irqs will normally be set up as input pins, but they can also be
+ * used as output pins ... which is convenient for testing.
+ *
+ * NOTE:  GPIO0..GPIO7 also have direct INTC hookups, which work in addition
+ * to their GPIOBNK0 irq (but with a bit less overhead).  But we don't have
+ * a good way to hook those up ...
+ *
+ * All those INTC hookups (GPIO0..GPIO7 plus five IRQ banks) can also
+ * serve as EDMA event triggers.
+ */
+
+static void gpio_irq_disable(unsigned irq)
+{
+	struct gpio_controller *__iomem g = get_irq_chip_data(irq);
+	u32 mask = __gpio_mask(irq_to_gpio(irq));
+
+	__raw_writel(mask, &g->clr_falling);
+	__raw_writel(mask, &g->clr_rising);
+}
+
+static void gpio_irq_enable(unsigned irq)
+{
+	struct gpio_controller *__iomem g = get_irq_chip_data(irq);
+	u32 mask = __gpio_mask(irq_to_gpio(irq));
+
+	if (irq_desc[irq].status & IRQ_TYPE_EDGE_FALLING)
+		__raw_writel(mask, &g->set_falling);
+	if (irq_desc[irq].status & IRQ_TYPE_EDGE_RISING)
+		__raw_writel(mask, &g->set_rising);
+}
+
+static int gpio_irq_type(unsigned irq, unsigned trigger)
+{
+	struct gpio_controller *__iomem g = get_irq_chip_data(irq);
+	u32 mask = __gpio_mask(irq_to_gpio(irq));
+
+	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+		return -EINVAL;
+
+	irq_desc[irq].status &= ~IRQ_TYPE_SENSE_MASK;
+	irq_desc[irq].status |= trigger;
+
+	__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
+		     ? &g->set_falling : &g->clr_falling);
+	__raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING)
+		     ? &g->set_rising : &g->clr_rising);
+	return 0;
+}
+
+static struct irq_chip gpio_irqchip = {
+	.name		= "GPIO",
+	.enable		= gpio_irq_enable,
+	.disable	= gpio_irq_disable,
+	.set_type	= gpio_irq_type,
+};
+
+static void
+gpio_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+	struct gpio_controller *__iomem g = get_irq_chip_data(irq);
+	u32 mask = 0xffff;
+
+	/* we only care about one bank */
+	if (irq & 1)
+		mask <<= 16;
+
+	/* temporarily mask (level sensitive) parent IRQ */
+	desc->chip->ack(irq);
+	while (1) {
+		u32		status;
+		struct irq_desc	*gpio;
+		int		n;
+		int		res;
+
+		/* ack any irqs */
+		status = __raw_readl(&g->intstat) & mask;
+		if (!status)
+			break;
+		__raw_writel(status, &g->intstat);
+		if (irq & 1)
+			status >>= 16;
+
+		/* now demux them to the right lowlevel handler */
+		n = (int)get_irq_data(irq);
+		gpio = &irq_desc[n];
+		while (status) {
+			res = ffs(status);
+			n += res;
+			gpio += res;
+			desc_handle_irq(n - 1, gpio - 1);
+			status >>= res;
+		}
+	}
+	desc->chip->unmask(irq);
+	/* now it may re-trigger */
+}
+
+/*
+ * NOTE:  for suspend/resume, probably best to make a sysdev (and class)
+ * with its suspend/resume calls hooking into the results of the set_wake()
+ * calls ... so if no gpios are wakeup events the clock can be disabled,
+ * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
+ * can be set appropriately for GPIOV33 pins.
+ */
+
+static int __init davinci_gpio_irq_setup(void)
+{
+	unsigned	gpio, irq, bank;
+	struct clk	*clk;
+
+	clk = clk_get(NULL, "gpio");
+	if (IS_ERR(clk)) {
+		printk(KERN_ERR "Error %ld getting gpio clock?\n",
+		       PTR_ERR(clk));
+		return 0;
+	}
+
+	clk_enable(clk);
+
+	for (gpio = 0, irq = gpio_to_irq(0), bank = IRQ_GPIOBNK0;
+	     gpio < DAVINCI_N_GPIO; bank++) {
+		struct gpio_controller	*__iomem g = gpio2controller(gpio);
+		unsigned		i;
+
+		__raw_writel(~0, &g->clr_falling);
+		__raw_writel(~0, &g->clr_rising);
+
+		/* set up all irqs in this bank */
+		set_irq_chained_handler(bank, gpio_irq_handler);
+		set_irq_chip_data(bank, g);
+		set_irq_data(bank, (void *)irq);
+
+		for (i = 0; i < 16 && gpio < DAVINCI_N_GPIO;
+		     i++, irq++, gpio++) {
+			set_irq_chip(irq, &gpio_irqchip);
+			set_irq_chip_data(irq, g);
+			set_irq_handler(irq, handle_simple_irq);
+			set_irq_flags(irq, IRQF_VALID);
+		}
+	}
+
+	/* BINTEN -- per-bank interrupt enable. genirq would also let these
+	 * bits be set/cleared dynamically.
+	 */
+	__raw_writel(0x1f, (void *__iomem)
+		     IO_ADDRESS(DAVINCI_GPIO_BASE + 0x08));
+
+	printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0));
+
+	return 0;
+}
+
+arch_initcall(davinci_gpio_irq_setup);