ARM: 7103/1: plat-pxa: move PXA GPIO driver to GPIO subsystem

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

Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 337 insertions, 0 deletions

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 84bc7389e36..19c5d27b6d2 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_GPIO_PCA953X)	+= gpio-pca953x.o
 obj-$(CONFIG_GPIO_PCF857X)	+= gpio-pcf857x.o
 obj-$(CONFIG_GPIO_PCH)		+= gpio-pch.o
 obj-$(CONFIG_GPIO_PL061)	+= gpio-pl061.o
+obj-$(CONFIG_PLAT_PXA)		+= gpio-pxa.o
 obj-$(CONFIG_GPIO_RDC321X)	+= gpio-rdc321x.o
 
 obj-$(CONFIG_GPIO_PLAT_SAMSUNG)	+= gpio-plat-samsung.o
diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
new file mode 100644
index 00000000000..5d6a86bfc68
--- /dev/null
+++ b/drivers/gpio/gpio-pxa.c
@@ -0,0 +1,336 @@
+/*
+ *  linux/arch/arm/plat-pxa/gpio.c
+ *
+ *  Generic PXA GPIO handling
+ *
+ *  Author:	Nicolas Pitre
+ *  Created:	Jun 15, 2001
+ *  Copyright:	MontaVista Software Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/syscore_ops.h>
+#include <linux/slab.h>
+
+int pxa_last_gpio;
+
+struct pxa_gpio_chip {
+	struct gpio_chip chip;
+	void __iomem	*regbase;
+	char label[10];
+
+	unsigned long	irq_mask;
+	unsigned long	irq_edge_rise;
+	unsigned long	irq_edge_fall;
+
+#ifdef CONFIG_PM
+	unsigned long	saved_gplr;
+	unsigned long	saved_gpdr;
+	unsigned long	saved_grer;
+	unsigned long	saved_gfer;
+#endif
+};
+
+static DEFINE_SPINLOCK(gpio_lock);
+static struct pxa_gpio_chip *pxa_gpio_chips;
+
+#define for_each_gpio_chip(i, c)			\
+	for (i = 0, c = &pxa_gpio_chips[0]; i <= pxa_last_gpio; i += 32, c++)
+
+static inline void __iomem *gpio_chip_base(struct gpio_chip *c)
+{
+	return container_of(c, struct pxa_gpio_chip, chip)->regbase;
+}
+
+static inline struct pxa_gpio_chip *gpio_to_pxachip(unsigned gpio)
+{
+	return &pxa_gpio_chips[gpio_to_bank(gpio)];
+}
+
+static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	void __iomem *base = gpio_chip_base(chip);
+	uint32_t value, mask = 1 << offset;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gpio_lock, flags);
+
+	value = __raw_readl(base + GPDR_OFFSET);
+	if (__gpio_is_inverted(chip->base + offset))
+		value |= mask;
+	else
+		value &= ~mask;
+	__raw_writel(value, base + GPDR_OFFSET);
+
+	spin_unlock_irqrestore(&gpio_lock, flags);
+	return 0;
+}
+
+static int pxa_gpio_direction_output(struct gpio_chip *chip,
+				     unsigned offset, int value)
+{
+	void __iomem *base = gpio_chip_base(chip);
+	uint32_t tmp, mask = 1 << offset;
+	unsigned long flags;
+
+	__raw_writel(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));
+
+	spin_lock_irqsave(&gpio_lock, flags);
+
+	tmp = __raw_readl(base + GPDR_OFFSET);
+	if (__gpio_is_inverted(chip->base + offset))
+		tmp &= ~mask;
+	else
+		tmp |= mask;
+	__raw_writel(tmp, base + GPDR_OFFSET);
+
+	spin_unlock_irqrestore(&gpio_lock, flags);
+	return 0;
+}
+
+static int pxa_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	return __raw_readl(gpio_chip_base(chip) + GPLR_OFFSET) & (1 << offset);
+}
+
+static void pxa_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	__raw_writel(1 << offset, gpio_chip_base(chip) +
+				(value ? GPSR_OFFSET : GPCR_OFFSET));
+}
+
+static int __init pxa_init_gpio_chip(int gpio_end)
+{
+	int i, gpio, nbanks = gpio_to_bank(gpio_end) + 1;
+	struct pxa_gpio_chip *chips;
+
+	chips = kzalloc(nbanks * sizeof(struct pxa_gpio_chip), GFP_KERNEL);
+	if (chips == NULL) {
+		pr_err("%s: failed to allocate GPIO chips\n", __func__);
+		return -ENOMEM;
+	}
+
+	for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) {
+		struct gpio_chip *c = &chips[i].chip;
+
+		sprintf(chips[i].label, "gpio-%d", i);
+		chips[i].regbase = (void __iomem *)GPIO_BANK(i);
+
+		c->base  = gpio;
+		c->label = chips[i].label;
+
+		c->direction_input  = pxa_gpio_direction_input;
+		c->direction_output = pxa_gpio_direction_output;
+		c->get = pxa_gpio_get;
+		c->set = pxa_gpio_set;
+
+		/* number of GPIOs on last bank may be less than 32 */
+		c->ngpio = (gpio + 31 > gpio_end) ? (gpio_end - gpio + 1) : 32;
+		gpiochip_add(c);
+	}
+	pxa_gpio_chips = chips;
+	return 0;
+}
+
+/* Update only those GRERx and GFERx edge detection register bits if those
+ * bits are set in c->irq_mask
+ */
+static inline void update_edge_detect(struct pxa_gpio_chip *c)
+{
+	uint32_t grer, gfer;
+
+	grer = __raw_readl(c->regbase + GRER_OFFSET) & ~c->irq_mask;
+	gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~c->irq_mask;
+	grer |= c->irq_edge_rise & c->irq_mask;
+	gfer |= c->irq_edge_fall & c->irq_mask;
+	__raw_writel(grer, c->regbase + GRER_OFFSET);
+	__raw_writel(gfer, c->regbase + GFER_OFFSET);
+}
+
+static int pxa_gpio_irq_type(struct irq_data *d, unsigned int type)
+{
+	struct pxa_gpio_chip *c;
+	int gpio = irq_to_gpio(d->irq);
+	unsigned long gpdr, mask = GPIO_bit(gpio);
+
+	c = gpio_to_pxachip(gpio);
+
+	if (type == IRQ_TYPE_PROBE) {
+		/* Don't mess with enabled GPIOs using preconfigured edges or
+		 * GPIOs set to alternate function or to output during probe
+		 */
+		if ((c->irq_edge_rise | c->irq_edge_fall) & GPIO_bit(gpio))
+			return 0;
+
+		if (__gpio_is_occupied(gpio))
+			return 0;
+
+		type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
+	}
+
+	gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
+
+	if (__gpio_is_inverted(gpio))
+		__raw_writel(gpdr | mask,  c->regbase + GPDR_OFFSET);
+	else
+		__raw_writel(gpdr & ~mask, c->regbase + GPDR_OFFSET);
+
+	if (type & IRQ_TYPE_EDGE_RISING)
+		c->irq_edge_rise |= mask;
+	else
+		c->irq_edge_rise &= ~mask;
+
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		c->irq_edge_fall |= mask;
+	else
+		c->irq_edge_fall &= ~mask;
+
+	update_edge_detect(c);
+
+	pr_debug("%s: IRQ%d (GPIO%d) - edge%s%s\n", __func__, d->irq, gpio,
+		((type & IRQ_TYPE_EDGE_RISING)  ? " rising"  : ""),
+		((type & IRQ_TYPE_EDGE_FALLING) ? " falling" : ""));
+	return 0;
+}
+
+static void pxa_gpio_demux_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct pxa_gpio_chip *c;
+	int loop, gpio, gpio_base, n;
+	unsigned long gedr;
+
+	do {
+		loop = 0;
+		for_each_gpio_chip(gpio, c) {
+			gpio_base = c->chip.base;
+
+			gedr = __raw_readl(c->regbase + GEDR_OFFSET);
+			gedr = gedr & c->irq_mask;
+			__raw_writel(gedr, c->regbase + GEDR_OFFSET);
+
+			n = find_first_bit(&gedr, BITS_PER_LONG);
+			while (n < BITS_PER_LONG) {
+				loop = 1;
+
+				generic_handle_irq(gpio_to_irq(gpio_base + n));
+				n = find_next_bit(&gedr, BITS_PER_LONG, n + 1);
+			}
+		}
+	} while (loop);
+}
+
+static void pxa_ack_muxed_gpio(struct irq_data *d)
+{
+	int gpio = irq_to_gpio(d->irq);
+	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);
+
+	__raw_writel(GPIO_bit(gpio), c->regbase + GEDR_OFFSET);
+}
+
+static void pxa_mask_muxed_gpio(struct irq_data *d)
+{
+	int gpio = irq_to_gpio(d->irq);
+	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);
+	uint32_t grer, gfer;
+
+	c->irq_mask &= ~GPIO_bit(gpio);
+
+	grer = __raw_readl(c->regbase + GRER_OFFSET) & ~GPIO_bit(gpio);
+	gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~GPIO_bit(gpio);
+	__raw_writel(grer, c->regbase + GRER_OFFSET);
+	__raw_writel(gfer, c->regbase + GFER_OFFSET);
+}
+
+static void pxa_unmask_muxed_gpio(struct irq_data *d)
+{
+	int gpio = irq_to_gpio(d->irq);
+	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);
+
+	c->irq_mask |= GPIO_bit(gpio);
+	update_edge_detect(c);
+}
+
+static struct irq_chip pxa_muxed_gpio_chip = {
+	.name		= "GPIO",
+	.irq_ack	= pxa_ack_muxed_gpio,
+	.irq_mask	= pxa_mask_muxed_gpio,
+	.irq_unmask	= pxa_unmask_muxed_gpio,
+	.irq_set_type	= pxa_gpio_irq_type,
+};
+
+void __init pxa_init_gpio(int mux_irq, int start, int end, set_wake_t fn)
+{
+	struct pxa_gpio_chip *c;
+	int gpio, irq;
+
+	pxa_last_gpio = end;
+
+	/* Initialize GPIO chips */
+	pxa_init_gpio_chip(end);
+
+	/* clear all GPIO edge detects */
+	for_each_gpio_chip(gpio, c) {
+		__raw_writel(0, c->regbase + GFER_OFFSET);
+		__raw_writel(0, c->regbase + GRER_OFFSET);
+		__raw_writel(~0,c->regbase + GEDR_OFFSET);
+	}
+
+	for (irq  = gpio_to_irq(start); irq <= gpio_to_irq(end); irq++) {
+		irq_set_chip_and_handler(irq, &pxa_muxed_gpio_chip,
+					 handle_edge_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+	}
+
+	/* Install handler for GPIO>=2 edge detect interrupts */
+	irq_set_chained_handler(mux_irq, pxa_gpio_demux_handler);
+	pxa_muxed_gpio_chip.irq_set_wake = fn;
+}
+
+#ifdef CONFIG_PM
+static int pxa_gpio_suspend(void)
+{
+	struct pxa_gpio_chip *c;
+	int gpio;
+
+	for_each_gpio_chip(gpio, c) {
+		c->saved_gplr = __raw_readl(c->regbase + GPLR_OFFSET);
+		c->saved_gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
+		c->saved_grer = __raw_readl(c->regbase + GRER_OFFSET);
+		c->saved_gfer = __raw_readl(c->regbase + GFER_OFFSET);
+
+		/* Clear GPIO transition detect bits */
+		__raw_writel(0xffffffff, c->regbase + GEDR_OFFSET);
+	}
+	return 0;
+}
+
+static void pxa_gpio_resume(void)
+{
+	struct pxa_gpio_chip *c;
+	int gpio;
+
+	for_each_gpio_chip(gpio, c) {
+		/* restore level with set/clear */
+		__raw_writel( c->saved_gplr, c->regbase + GPSR_OFFSET);
+		__raw_writel(~c->saved_gplr, c->regbase + GPCR_OFFSET);
+
+		__raw_writel(c->saved_grer, c->regbase + GRER_OFFSET);
+		__raw_writel(c->saved_gfer, c->regbase + GFER_OFFSET);
+		__raw_writel(c->saved_gpdr, c->regbase + GPDR_OFFSET);
+	}
+}
+#else
+#define pxa_gpio_suspend	NULL
+#define pxa_gpio_resume		NULL
+#endif
+
+struct syscore_ops pxa_gpio_syscore_ops = {
+	.suspend	= pxa_gpio_suspend,
+	.resume		= pxa_gpio_resume,
+};