ARM: 7038/1: mach-davinci: move GPIO driver to GPIO subsystem

As per example from the other ARM boards, push the DaVinci GPIO
driver down to the GPIO subsystem so it can be consolidated.

Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 458 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c
new file mode 100644
index 00000000000..a8066e8edad
--- /dev/null
+++ b/drivers/gpio/gpio-davinci.c
@@ -0,0 +1,458 @@
+/*
+ * TI DaVinci GPIO Support
+ *
+ * Copyright (c) 2006-2007 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/gpio.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <asm/mach/irq.h>
+
+struct davinci_gpio_regs {
+	u32	dir;
+	u32	out_data;
+	u32	set_data;
+	u32	clr_data;
+	u32	in_data;
+	u32	set_rising;
+	u32	clr_rising;
+	u32	set_falling;
+	u32	clr_falling;
+	u32	intstat;
+};
+
+#define chip2controller(chip)	\
+	container_of(chip, struct davinci_gpio_controller, chip)
+
+static struct davinci_gpio_controller chips[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)];
+static void __iomem *gpio_base;
+
+static struct davinci_gpio_regs __iomem __init *gpio2regs(unsigned gpio)
+{
+	void __iomem *ptr;
+
+	if (gpio < 32 * 1)
+		ptr = gpio_base + 0x10;
+	else if (gpio < 32 * 2)
+		ptr = gpio_base + 0x38;
+	else if (gpio < 32 * 3)
+		ptr = gpio_base + 0x60;
+	else if (gpio < 32 * 4)
+		ptr = gpio_base + 0x88;
+	else if (gpio < 32 * 5)
+		ptr = gpio_base + 0xb0;
+	else
+		ptr = NULL;
+	return ptr;
+}
+
+static inline struct davinci_gpio_regs __iomem *irq2regs(int irq)
+{
+	struct davinci_gpio_regs __iomem *g;
+
+	g = (__force struct davinci_gpio_regs __iomem *)irq_get_chip_data(irq);
+
+	return g;
+}
+
+static int __init davinci_gpio_irq_setup(void);
+
+/*--------------------------------------------------------------------------*/
+
+/* board setup code *MUST* setup pinmux and enable the GPIO clock. */
+static inline int __davinci_direction(struct gpio_chip *chip,
+			unsigned offset, bool out, int value)
+{
+	struct davinci_gpio_controller *d = chip2controller(chip);
+	struct davinci_gpio_regs __iomem *g = d->regs;
+	unsigned long flags;
+	u32 temp;
+	u32 mask = 1 << offset;
+
+	spin_lock_irqsave(&d->lock, flags);
+	temp = __raw_readl(&g->dir);
+	if (out) {
+		temp &= ~mask;
+		__raw_writel(mask, value ? &g->set_data : &g->clr_data);
+	} else {
+		temp |= mask;
+	}
+	__raw_writel(temp, &g->dir);
+	spin_unlock_irqrestore(&d->lock, flags);
+
+	return 0;
+}
+
+static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+	return __davinci_direction(chip, offset, false, 0);
+}
+
+static int
+davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
+{
+	return __davinci_direction(chip, offset, true, value);
+}
+
+/*
+ * 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.
+ */
+static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *d = chip2controller(chip);
+	struct davinci_gpio_regs __iomem *g = d->regs;
+
+	return (1 << offset) & __raw_readl(&g->in_data);
+}
+
+/*
+ * Assuming the pin is muxed as a gpio output, set its output value.
+ */
+static void
+davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct davinci_gpio_controller *d = chip2controller(chip);
+	struct davinci_gpio_regs __iomem *g = d->regs;
+
+	__raw_writel((1 << offset), value ? &g->set_data : &g->clr_data);
+}
+
+static int __init davinci_gpio_setup(void)
+{
+	int i, base;
+	unsigned ngpio;
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+	struct davinci_gpio_regs *regs;
+
+	if (soc_info->gpio_type != GPIO_TYPE_DAVINCI)
+		return 0;
+
+	/*
+	 * The gpio banks conceptually expose a segmented bitmap,
+	 * and "ngpio" is one more than the largest zero-based
+	 * bit index that's valid.
+	 */
+	ngpio = soc_info->gpio_num;
+	if (ngpio == 0) {
+		pr_err("GPIO setup:  how many GPIOs?\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON(DAVINCI_N_GPIO < ngpio))
+		ngpio = DAVINCI_N_GPIO;
+
+	gpio_base = ioremap(soc_info->gpio_base, SZ_4K);
+	if (WARN_ON(!gpio_base))
+		return -ENOMEM;
+
+	for (i = 0, base = 0; base < ngpio; i++, base += 32) {
+		chips[i].chip.label = "DaVinci";
+
+		chips[i].chip.direction_input = davinci_direction_in;
+		chips[i].chip.get = davinci_gpio_get;
+		chips[i].chip.direction_output = davinci_direction_out;
+		chips[i].chip.set = davinci_gpio_set;
+
+		chips[i].chip.base = base;
+		chips[i].chip.ngpio = ngpio - base;
+		if (chips[i].chip.ngpio > 32)
+			chips[i].chip.ngpio = 32;
+
+		spin_lock_init(&chips[i].lock);
+
+		regs = gpio2regs(base);
+		chips[i].regs = regs;
+		chips[i].set_data = &regs->set_data;
+		chips[i].clr_data = &regs->clr_data;
+		chips[i].in_data = &regs->in_data;
+
+		gpiochip_add(&chips[i].chip);
+	}
+
+	soc_info->gpio_ctlrs = chips;
+	soc_info->gpio_ctlrs_num = DIV_ROUND_UP(ngpio, 32);
+
+	davinci_gpio_irq_setup();
+	return 0;
+}
+pure_initcall(davinci_gpio_setup);
+
+/*--------------------------------------------------------------------------*/
+/*
+ * 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:  The first few GPIOs also have direct INTC hookups in addition
+ * to their GPIOBNK0 irq, with a bit less overhead.
+ *
+ * All those INTC hookups (direct, plus several IRQ banks) can also
+ * serve as EDMA event triggers.
+ */
+
+static void gpio_irq_disable(struct irq_data *d)
+{
+	struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
+	u32 mask = (u32) irq_data_get_irq_handler_data(d);
+
+	__raw_writel(mask, &g->clr_falling);
+	__raw_writel(mask, &g->clr_rising);
+}
+
+static void gpio_irq_enable(struct irq_data *d)
+{
+	struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
+	u32 mask = (u32) irq_data_get_irq_handler_data(d);
+	unsigned status = irqd_get_trigger_type(d);
+
+	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
+	if (!status)
+		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
+
+	if (status & IRQ_TYPE_EDGE_FALLING)
+		__raw_writel(mask, &g->set_falling);
+	if (status & IRQ_TYPE_EDGE_RISING)
+		__raw_writel(mask, &g->set_rising);
+}
+
+static int gpio_irq_type(struct irq_data *d, unsigned trigger)
+{
+	struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
+	u32 mask = (u32) irq_data_get_irq_handler_data(d);
+
+	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct irq_chip gpio_irqchip = {
+	.name		= "GPIO",
+	.irq_enable	= gpio_irq_enable,
+	.irq_disable	= gpio_irq_disable,
+	.irq_set_type	= gpio_irq_type,
+	.flags		= IRQCHIP_SET_TYPE_MASKED,
+};
+
+static void
+gpio_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+	struct davinci_gpio_regs __iomem *g;
+	u32 mask = 0xffff;
+	struct davinci_gpio_controller *d;
+
+	d = (struct davinci_gpio_controller *)irq_desc_get_handler_data(desc);
+	g = (struct davinci_gpio_regs __iomem *)d->regs;
+
+	/* we only care about one bank */
+	if (irq & 1)
+		mask <<= 16;
+
+	/* temporarily mask (level sensitive) parent IRQ */
+	desc->irq_data.chip->irq_mask(&desc->irq_data);
+	desc->irq_data.chip->irq_ack(&desc->irq_data);
+	while (1) {
+		u32		status;
+		int		n;
+		int		res;
+
+		/* ack any irqs */
+		status = __raw_readl(&g->intstat) & mask;
+		if (!status)
+			break;
+		__raw_writel(status, &g->intstat);
+
+		/* now demux them to the right lowlevel handler */
+		n = d->irq_base;
+		if (irq & 1) {
+			n += 16;
+			status >>= 16;
+		}
+
+		while (status) {
+			res = ffs(status);
+			n += res;
+			generic_handle_irq(n - 1);
+			status >>= res;
+		}
+	}
+	desc->irq_data.chip->irq_unmask(&desc->irq_data);
+	/* now it may re-trigger */
+}
+
+static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *d = chip2controller(chip);
+
+	if (d->irq_base >= 0)
+		return d->irq_base + offset;
+	else
+		return -ENODEV;
+}
+
+static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+
+	/* NOTE:  we assume for now that only irqs in the first gpio_chip
+	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
+	 */
+	if (offset < soc_info->gpio_unbanked)
+		return soc_info->gpio_irq + offset;
+	else
+		return -ENODEV;
+}
+
+static int gpio_irq_type_unbanked(struct irq_data *d, unsigned trigger)
+{
+	struct davinci_gpio_regs __iomem *g = irq2regs(d->irq);
+	u32 mask = (u32) irq_data_get_irq_handler_data(d);
+
+	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+		return -EINVAL;
+
+	__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;
+}
+
+/*
+ * NOTE:  for suspend/resume, probably best to make a platform_device with
+ * suspend_late/resume_resume calls hooking into 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
+ * (dm6446) can be set appropriately for GPIOV33 pins.
+ */
+
+static int __init davinci_gpio_irq_setup(void)
+{
+	unsigned	gpio, irq, bank;
+	struct clk	*clk;
+	u32		binten = 0;
+	unsigned	ngpio, bank_irq;
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+	struct davinci_gpio_regs	__iomem *g;
+
+	ngpio = soc_info->gpio_num;
+
+	bank_irq = soc_info->gpio_irq;
+	if (bank_irq == 0) {
+		printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
+		return -EINVAL;
+	}
+
+	clk = clk_get(NULL, "gpio");
+	if (IS_ERR(clk)) {
+		printk(KERN_ERR "Error %ld getting gpio clock?\n",
+		       PTR_ERR(clk));
+		return PTR_ERR(clk);
+	}
+	clk_enable(clk);
+
+	/* Arrange gpio_to_irq() support, handling either direct IRQs or
+	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct
+	 * IRQs, while the others use banked IRQs, would need some setup
+	 * tweaks to recognize hardware which can do that.
+	 */
+	for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
+		chips[bank].chip.to_irq = gpio_to_irq_banked;
+		chips[bank].irq_base = soc_info->gpio_unbanked
+			? -EINVAL
+			: (soc_info->intc_irq_num + gpio);
+	}
+
+	/*
+	 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
+	 * controller only handling trigger modes.  We currently assume no
+	 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
+	 */
+	if (soc_info->gpio_unbanked) {
+		static struct irq_chip gpio_irqchip_unbanked;
+
+		/* pass "bank 0" GPIO IRQs to AINTC */
+		chips[0].chip.to_irq = gpio_to_irq_unbanked;
+		binten = BIT(0);
+
+		/* AINTC handles mask/unmask; GPIO handles triggering */
+		irq = bank_irq;
+		gpio_irqchip_unbanked = *irq_get_chip(irq);
+		gpio_irqchip_unbanked.name = "GPIO-AINTC";
+		gpio_irqchip_unbanked.irq_set_type = gpio_irq_type_unbanked;
+
+		/* default trigger: both edges */
+		g = gpio2regs(0);
+		__raw_writel(~0, &g->set_falling);
+		__raw_writel(~0, &g->set_rising);
+
+		/* set the direct IRQs up to use that irqchip */
+		for (gpio = 0; gpio < soc_info->gpio_unbanked; gpio++, irq++) {
+			irq_set_chip(irq, &gpio_irqchip_unbanked);
+			irq_set_handler_data(irq, (void *)__gpio_mask(gpio));
+			irq_set_chip_data(irq, (__force void *)g);
+			irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH);
+		}
+
+		goto done;
+	}
+
+	/*
+	 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
+	 * then chain through our own handler.
+	 */
+	for (gpio = 0, irq = gpio_to_irq(0), bank = 0;
+			gpio < ngpio;
+			bank++, bank_irq++) {
+		unsigned		i;
+
+		/* disabled by default, enabled only as needed */
+		g = gpio2regs(gpio);
+		__raw_writel(~0, &g->clr_falling);
+		__raw_writel(~0, &g->clr_rising);
+
+		/* set up all irqs in this bank */
+		irq_set_chained_handler(bank_irq, gpio_irq_handler);
+
+		/*
+		 * Each chip handles 32 gpios, and each irq bank consists of 16
+		 * gpio irqs. Pass the irq bank's corresponding controller to
+		 * the chained irq handler.
+		 */
+		irq_set_handler_data(bank_irq, &chips[gpio / 32]);
+
+		for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) {
+			irq_set_chip(irq, &gpio_irqchip);
+			irq_set_chip_data(irq, (__force void *)g);
+			irq_set_handler_data(irq, (void *)__gpio_mask(gpio));
+			irq_set_handler(irq, handle_simple_irq);
+			set_irq_flags(irq, IRQF_VALID);
+		}
+
+		binten |= BIT(bank);
+	}
+
+done:
+	/* BINTEN -- per-bank interrupt enable. genirq would also let these
+	 * bits be set/cleared dynamically.
+	 */
+	__raw_writel(binten, gpio_base + 0x08);
+
+	printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0));
+
+	return 0;
+}