pinctrl: add bcm2835 driver

The BCM2835 GPIO module is a combined GPIO controller, (GPIO) interrupt
controller, and pinmux/control device.

Original driver by Simon Arlott.
Rewrite including GPIO chip device by Chris Boot.

Upstreaming changes by Stephen Warren:
* Wrote DT binding documentation.
* Changed brcm,function to an integer to more directly match the
  datasheet, and to match brcm,pins being an integer.
* Implemented pull-up/down pin config.
* Removed read-only DT property and related code. The restriction this
  implemented are driven by the board, not the GPIO HW block, so don't
  really make sense of a HW block binding, were in general incomplete
  (since they could only know about the few pins hard-coded into the
  Raspberry Pi B board design and not the uncommitted GPIOS), and are
  better represented simply by not writing incorrect data into pin
  configuration nodes.
* Don't set GPIO_IN function select in gpio_request_enable() to avoid
  glitches; defer this to gpio_set_direction(). Consequently, removed
  empty bcm2835_pmx_gpio_request_enable().
* Simplified enabled_irq_map[]; make it explicitly 1 entry per bank.
* Lifted use of enabled_irq_map[] outside the per-interrupt loop in
  IRQ handler, thus fixing an issue where the code was indexing into
  enabled_irq_map[] by intra-bank GPIO ID, not global GPIO ID.
* Removed locking in IRQ handler, since all other code uses
  spin_lock_irqsave() and so guarantees it doesn't run concurrently
  with the handler.
* Moved duplicated BUILD_BUG_ON()s into probe(). Also check size of
  bcm2835_gpio_pins[].
* Remove range-checking from bcm2835_pctl_get_groups_count() since we've
  decided to trust the pinctrl core.
* Made bcm2835_pmx_gpio_disable_free() call bcm2835_pinctrl_fsel_set()
  directly for simplicity.
* Fixed body of dt_free_map() to match latest dt_node_to_map().
* Removed GPIO ownership check from bcm2835_pmx_enable() since the pinctrl
  core owns doing this.
* Made irq_chip and pinctrl_gpio_range .name == MODULE_NAME so it's more
  descriptive.
* Simplified remove(); removed call to non-existent
  pinctrl_remove_gpio_range(), remove early return on error.
* Don't force gpiochip's base to 0. Set gpio_range.base to gpiochip's
  base GPIO number.
* Error-handling cleanups in probe().
* Switched to module_platform_driver() rather than open-coding.
* Made pin, group, and function names lower-case.
* s/broadcom/brcm/ in DT property names.
* s/2708/2835/.
* Fixed a couple minor checkpatch warnings, and other minor cleanup.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 1081 insertions, 0 deletions

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 73aafd96271f..0cf12896a6f2 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -26,6 +26,11 @@ config DEBUG_PINCTRL
 	help
 	  Say Y here to add some extra checks and diagnostics to PINCTRL calls.
 
+config PINCTRL_BCM2835
+	bool
+	select PINMUX
+	select PINCONF
+
 config PINCTRL_IMX
 	bool
 	select PINMUX
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index cda3984951e2..84952a2db83c 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -9,6 +9,7 @@ ifeq ($(CONFIG_OF),y)
 obj-$(CONFIG_PINCTRL)		+= devicetree.o
 endif
 obj-$(CONFIG_GENERIC_PINCONF)	+= pinconf-generic.o
+obj-$(CONFIG_PINCTRL_BCM2835)	+= pinctrl-bcm2835.o
 obj-$(CONFIG_PINCTRL_IMX)	+= pinctrl-imx.o
 obj-$(CONFIG_PINCTRL_IMX35)	+= pinctrl-imx35.o
 obj-$(CONFIG_PINCTRL_IMX51)	+= pinctrl-imx51.o
diff --git a/drivers/pinctrl/pinctrl-bcm2835.c b/drivers/pinctrl/pinctrl-bcm2835.c
new file mode 100644
index 000000000000..a4adee633fa9
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-bcm2835.c
@@ -0,0 +1,1075 @@
+/*
+ * Driver for Broadcom BCM2835 GPIO unit (pinctrl + GPIO)
+ *
+ * Copyright (C) 2012 Chris Boot, Simon Arlott, Stephen Warren
+ *
+ * This driver is inspired by:
+ * pinctrl-nomadik.c, please see original file for copyright information
+ * pinctrl-tegra.c, please see original file for copyright information
+ *
+ * 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.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/bug.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdesc.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/platform_device.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define MODULE_NAME "pinctrl-bcm2835"
+#define BCM2835_NUM_GPIOS 54
+#define BCM2835_NUM_BANKS 2
+
+#define BCM2835_PIN_BITMAP_SZ \
+	DIV_ROUND_UP(BCM2835_NUM_GPIOS, sizeof(unsigned long) * 8)
+
+/* GPIO register offsets */
+#define GPFSEL0		0x0	/* Function Select */
+#define GPSET0		0x1c	/* Pin Output Set */
+#define GPCLR0		0x28	/* Pin Output Clear */
+#define GPLEV0		0x34	/* Pin Level */
+#define GPEDS0		0x40	/* Pin Event Detect Status */
+#define GPREN0		0x4c	/* Pin Rising Edge Detect Enable */
+#define GPFEN0		0x58	/* Pin Falling Edge Detect Enable */
+#define GPHEN0		0x64	/* Pin High Detect Enable */
+#define GPLEN0		0x70	/* Pin Low Detect Enable */
+#define GPAREN0		0x7c	/* Pin Async Rising Edge Detect */
+#define GPAFEN0		0x88	/* Pin Async Falling Edge Detect */
+#define GPPUD		0x94	/* Pin Pull-up/down Enable */
+#define GPPUDCLK0	0x98	/* Pin Pull-up/down Enable Clock */
+
+#define FSEL_REG(p)		(GPFSEL0 + (((p) / 10) * 4))
+#define FSEL_SHIFT(p)		(((p) % 10) * 3)
+#define GPIO_REG_OFFSET(p)	((p) / 32)
+#define GPIO_REG_SHIFT(p)	((p) % 32)
+
+enum bcm2835_pinconf_param {
+	/* argument: bcm2835_pinconf_pull */
+	BCM2835_PINCONF_PARAM_PULL,
+};
+
+enum bcm2835_pinconf_pull {
+	BCM2835_PINCONFIG_PULL_NONE,
+	BCM2835_PINCONFIG_PULL_DOWN,
+	BCM2835_PINCONFIG_PULL_UP,
+};
+
+#define BCM2835_PINCONF_PACK(_param_, _arg_) ((_param_) << 16 | (_arg_))
+#define BCM2835_PINCONF_UNPACK_PARAM(_conf_) ((_conf_) >> 16)
+#define BCM2835_PINCONF_UNPACK_ARG(_conf_) ((_conf_) & 0xffff)
+
+struct bcm2835_gpio_irqdata {
+	struct bcm2835_pinctrl *pc;
+	int bank;
+};
+
+struct bcm2835_pinctrl {
+	struct device *dev;
+	void __iomem *base;
+	int irq[BCM2835_NUM_BANKS];
+
+	/* note: locking assumes each bank will have its own unsigned long */
+	unsigned long enabled_irq_map[BCM2835_NUM_BANKS];
+	unsigned int irq_type[BCM2835_NUM_GPIOS];
+
+	struct pinctrl_dev *pctl_dev;
+	struct irq_domain *irq_domain;
+	struct gpio_chip gpio_chip;
+	struct pinctrl_gpio_range gpio_range;
+
+	struct bcm2835_gpio_irqdata irq_data[BCM2835_NUM_BANKS];
+	spinlock_t irq_lock[BCM2835_NUM_BANKS];
+};
+
+static struct lock_class_key gpio_lock_class;
+
+/* pins are just named GPIO0..GPIO53 */
+#define BCM2835_GPIO_PIN(a) PINCTRL_PIN(a, "gpio" #a)
+struct pinctrl_pin_desc bcm2835_gpio_pins[] = {
+	BCM2835_GPIO_PIN(0),
+	BCM2835_GPIO_PIN(1),
+	BCM2835_GPIO_PIN(2),
+	BCM2835_GPIO_PIN(3),
+	BCM2835_GPIO_PIN(4),
+	BCM2835_GPIO_PIN(5),
+	BCM2835_GPIO_PIN(6),
+	BCM2835_GPIO_PIN(7),
+	BCM2835_GPIO_PIN(8),
+	BCM2835_GPIO_PIN(9),
+	BCM2835_GPIO_PIN(10),
+	BCM2835_GPIO_PIN(11),
+	BCM2835_GPIO_PIN(12),
+	BCM2835_GPIO_PIN(13),
+	BCM2835_GPIO_PIN(14),
+	BCM2835_GPIO_PIN(15),
+	BCM2835_GPIO_PIN(16),
+	BCM2835_GPIO_PIN(17),
+	BCM2835_GPIO_PIN(18),
+	BCM2835_GPIO_PIN(19),
+	BCM2835_GPIO_PIN(20),
+	BCM2835_GPIO_PIN(21),
+	BCM2835_GPIO_PIN(22),
+	BCM2835_GPIO_PIN(23),
+	BCM2835_GPIO_PIN(24),
+	BCM2835_GPIO_PIN(25),
+	BCM2835_GPIO_PIN(26),
+	BCM2835_GPIO_PIN(27),
+	BCM2835_GPIO_PIN(28),
+	BCM2835_GPIO_PIN(29),
+	BCM2835_GPIO_PIN(30),
+	BCM2835_GPIO_PIN(31),
+	BCM2835_GPIO_PIN(32),
+	BCM2835_GPIO_PIN(33),
+	BCM2835_GPIO_PIN(34),
+	BCM2835_GPIO_PIN(35),
+	BCM2835_GPIO_PIN(36),
+	BCM2835_GPIO_PIN(37),
+	BCM2835_GPIO_PIN(38),
+	BCM2835_GPIO_PIN(39),
+	BCM2835_GPIO_PIN(40),
+	BCM2835_GPIO_PIN(41),
+	BCM2835_GPIO_PIN(42),
+	BCM2835_GPIO_PIN(43),
+	BCM2835_GPIO_PIN(44),
+	BCM2835_GPIO_PIN(45),
+	BCM2835_GPIO_PIN(46),
+	BCM2835_GPIO_PIN(47),
+	BCM2835_GPIO_PIN(48),
+	BCM2835_GPIO_PIN(49),
+	BCM2835_GPIO_PIN(50),
+	BCM2835_GPIO_PIN(51),
+	BCM2835_GPIO_PIN(52),
+	BCM2835_GPIO_PIN(53),
+};
+
+/* one pin per group */
+static const char * const bcm2835_gpio_groups[] = {
+	"gpio0",
+	"gpio1",
+	"gpio2",
+	"gpio3",
+	"gpio4",
+	"gpio5",
+	"gpio6",
+	"gpio7",
+	"gpio8",
+	"gpio9",
+	"gpio10",
+	"gpio11",
+	"gpio12",
+	"gpio13",
+	"gpio14",
+	"gpio15",
+	"gpio16",
+	"gpio17",
+	"gpio18",
+	"gpio19",
+	"gpio20",
+	"gpio21",
+	"gpio22",
+	"gpio23",
+	"gpio24",
+	"gpio25",
+	"gpio26",
+	"gpio27",
+	"gpio28",
+	"gpio29",
+	"gpio30",
+	"gpio31",
+	"gpio32",
+	"gpio33",
+	"gpio34",
+	"gpio35",
+	"gpio36",
+	"gpio37",
+	"gpio38",
+	"gpio39",
+	"gpio40",
+	"gpio41",
+	"gpio42",
+	"gpio43",
+	"gpio44",
+	"gpio45",
+	"gpio46",
+	"gpio47",
+	"gpio48",
+	"gpio49",
+	"gpio50",
+	"gpio51",
+	"gpio52",
+	"gpio53",
+};
+
+enum bcm2835_fsel {
+	BCM2835_FSEL_GPIO_IN = 0,
+	BCM2835_FSEL_GPIO_OUT = 1,
+	BCM2835_FSEL_ALT0 = 4,
+	BCM2835_FSEL_ALT1 = 5,
+	BCM2835_FSEL_ALT2 = 6,
+	BCM2835_FSEL_ALT3 = 7,
+	BCM2835_FSEL_ALT4 = 3,
+	BCM2835_FSEL_ALT5 = 2,
+	BCM2835_FSEL_COUNT = 8,
+	BCM2835_FSEL_MASK = 0x7,
+};
+
+static const char * const bcm2835_functions[BCM2835_FSEL_COUNT] = {
+	[BCM2835_FSEL_GPIO_IN] = "gpio_in",
+	[BCM2835_FSEL_GPIO_OUT] = "gpio_out",
+	[BCM2835_FSEL_ALT0] = "alt0",
+	[BCM2835_FSEL_ALT1] = "alt1",
+	[BCM2835_FSEL_ALT2] = "alt2",
+	[BCM2835_FSEL_ALT3] = "alt3",
+	[BCM2835_FSEL_ALT4] = "alt4",
+	[BCM2835_FSEL_ALT5] = "alt5",
+};
+
+static const char * const irq_type_names[] = {
+	[IRQ_TYPE_NONE] = "none",
+	[IRQ_TYPE_EDGE_RISING] = "edge-rising",
+	[IRQ_TYPE_EDGE_FALLING] = "edge-falling",
+	[IRQ_TYPE_EDGE_BOTH] = "edge-both",
+	[IRQ_TYPE_LEVEL_HIGH] = "level-high",
+	[IRQ_TYPE_LEVEL_LOW] = "level-low",
+};
+
+static inline u32 bcm2835_gpio_rd(struct bcm2835_pinctrl *pc, unsigned reg)
+{
+	return readl(pc->base + reg);
+}
+
+static inline void bcm2835_gpio_wr(struct bcm2835_pinctrl *pc, unsigned reg,
+		u32 val)
+{
+	writel(val, pc->base + reg);
+}
+
+static inline int bcm2835_gpio_get_bit(struct bcm2835_pinctrl *pc, unsigned reg,
+		unsigned bit)
+{
+	reg += GPIO_REG_OFFSET(bit) * 4;
+	return (bcm2835_gpio_rd(pc, reg) >> GPIO_REG_SHIFT(bit)) & 1;
+}
+
+/* note NOT a read/modify/write cycle */
+static inline void bcm2835_gpio_set_bit(struct bcm2835_pinctrl *pc,
+		unsigned reg, unsigned bit)
+{
+	reg += GPIO_REG_OFFSET(bit) * 4;
+	bcm2835_gpio_wr(pc, reg, BIT(GPIO_REG_SHIFT(bit)));
+}
+
+static inline enum bcm2835_fsel bcm2835_pinctrl_fsel_get(
+		struct bcm2835_pinctrl *pc, unsigned pin)
+{
+	u32 val = bcm2835_gpio_rd(pc, FSEL_REG(pin));
+	enum bcm2835_fsel status = (val >> FSEL_SHIFT(pin)) & BCM2835_FSEL_MASK;
+
+	dev_dbg(pc->dev, "get %08x (%u => %s)\n", val, pin,
+			bcm2835_functions[status]);
+
+	return status;
+}
+
+static inline void bcm2835_pinctrl_fsel_set(
+		struct bcm2835_pinctrl *pc, unsigned pin,
+		enum bcm2835_fsel fsel)
+{
+	u32 val = bcm2835_gpio_rd(pc, FSEL_REG(pin));
+	enum bcm2835_fsel cur = (val >> FSEL_SHIFT(pin)) & BCM2835_FSEL_MASK;
+
+	dev_dbg(pc->dev, "read %08x (%u => %s)\n", val, pin,
+			bcm2835_functions[cur]);
+
+	if (cur == fsel)
+		return;
+
+	if (cur != BCM2835_FSEL_GPIO_IN && fsel != BCM2835_FSEL_GPIO_IN) {
+		/* always transition through GPIO_IN */
+		val &= ~(BCM2835_FSEL_MASK << FSEL_SHIFT(pin));
+		val |= BCM2835_FSEL_GPIO_IN << FSEL_SHIFT(pin);
+
+		dev_dbg(pc->dev, "trans %08x (%u <= %s)\n", val, pin,
+				bcm2835_functions[BCM2835_FSEL_GPIO_IN]);
+		bcm2835_gpio_wr(pc, FSEL_REG(pin), val);
+	}
+
+	val &= ~(BCM2835_FSEL_MASK << FSEL_SHIFT(pin));
+	val |= fsel << FSEL_SHIFT(pin);
+
+	dev_dbg(pc->dev, "write %08x (%u <= %s)\n", val, pin,
+			bcm2835_functions[fsel]);
+	bcm2835_gpio_wr(pc, FSEL_REG(pin), val);
+}
+
+static int bcm2835_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void bcm2835_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	pinctrl_free_gpio(chip->base + offset);
+}
+
+static int bcm2835_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	return pinctrl_gpio_direction_input(chip->base + offset);
+}
+
+static int bcm2835_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct bcm2835_pinctrl *pc = dev_get_drvdata(chip->dev);
+
+	return bcm2835_gpio_get_bit(pc, GPLEV0, offset);
+}
+
+static int bcm2835_gpio_direction_output(struct gpio_chip *chip,
+		unsigned offset, int value)
+{
+	return pinctrl_gpio_direction_output(chip->base + offset);
+}
+
+static void bcm2835_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct bcm2835_pinctrl *pc = dev_get_drvdata(chip->dev);
+
+	bcm2835_gpio_set_bit(pc, value ? GPSET0 : GPCLR0, offset);
+}
+
+static int bcm2835_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct bcm2835_pinctrl *pc = dev_get_drvdata(chip->dev);
+
+	return irq_linear_revmap(pc->irq_domain, offset);
+}
+
+static struct gpio_chip bcm2835_gpio_chip __devinitconst = {
+	.label = MODULE_NAME,
+	.owner = THIS_MODULE,
+	.request = bcm2835_gpio_request,
+	.free = bcm2835_gpio_free,
+	.direction_input = bcm2835_gpio_direction_input,
+	.direction_output = bcm2835_gpio_direction_output,
+	.get = bcm2835_gpio_get,
+	.set = bcm2835_gpio_set,
+	.to_irq = bcm2835_gpio_to_irq,
+	.base = -1,
+	.ngpio = BCM2835_NUM_GPIOS,
+	.can_sleep = 0,
+};
+
+static irqreturn_t bcm2835_gpio_irq_handler(int irq, void *dev_id)
+{
+	struct bcm2835_gpio_irqdata *irqdata = dev_id;
+	struct bcm2835_pinctrl *pc = irqdata->pc;
+	int bank = irqdata->bank;
+	unsigned long events;
+	unsigned offset;
+	unsigned gpio;
+	unsigned int type;
+
+	events = bcm2835_gpio_rd(pc, GPEDS0 + bank * 4);
+	events &= pc->enabled_irq_map[bank];
+	for_each_set_bit(offset, &events, 32) {
+		gpio = (32 * bank) + offset;
+		type = pc->irq_type[gpio];
+
+		/* ack edge triggered IRQs immediately */
+		if (!(type & IRQ_TYPE_LEVEL_MASK))
+			bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
+
+		generic_handle_irq(irq_linear_revmap(pc->irq_domain, gpio));
+
+		/* ack level triggered IRQ after handling them */
+		if (type & IRQ_TYPE_LEVEL_MASK)
+			bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
+	}
+	return events ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static inline void __bcm2835_gpio_irq_config(struct bcm2835_pinctrl *pc,
+	unsigned reg, unsigned offset, bool enable)
+{
+	u32 value;
+	reg += GPIO_REG_OFFSET(offset) * 4;
+	value = bcm2835_gpio_rd(pc, reg);
+	if (enable)
+		value |= BIT(GPIO_REG_SHIFT(offset));
+	else
+		value &= ~(BIT(GPIO_REG_SHIFT(offset)));
+	bcm2835_gpio_wr(pc, reg, value);
+}
+
+/* fast path for IRQ handler */
+static void bcm2835_gpio_irq_config(struct bcm2835_pinctrl *pc,
+	unsigned offset, bool enable)
+{
+	switch (pc->irq_type[offset]) {
+	case IRQ_TYPE_EDGE_RISING:
+		__bcm2835_gpio_irq_config(pc, GPREN0, offset, enable);
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		__bcm2835_gpio_irq_config(pc, GPFEN0, offset, enable);
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		__bcm2835_gpio_irq_config(pc, GPREN0, offset, enable);
+		__bcm2835_gpio_irq_config(pc, GPFEN0, offset, enable);
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		__bcm2835_gpio_irq_config(pc, GPHEN0, offset, enable);
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		__bcm2835_gpio_irq_config(pc, GPLEN0, offset, enable);
+		break;
+	}
+}
+
+static void bcm2835_gpio_irq_enable(struct irq_data *data)
+{
+	struct bcm2835_pinctrl *pc = irq_data_get_irq_chip_data(data);
+	unsigned gpio = irqd_to_hwirq(data);
+	unsigned offset = GPIO_REG_SHIFT(gpio);
+	unsigned bank = GPIO_REG_OFFSET(gpio);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pc->irq_lock[bank], flags);
+	set_bit(offset, &pc->enabled_irq_map[bank]);
+	bcm2835_gpio_irq_config(pc, gpio, true);
+	spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
+}
+
+static void bcm2835_gpio_irq_disable(struct irq_data *data)
+{
+	struct bcm2835_pinctrl *pc = irq_data_get_irq_chip_data(data);
+	unsigned gpio = irqd_to_hwirq(data);
+	unsigned offset = GPIO_REG_SHIFT(gpio);
+	unsigned bank = GPIO_REG_OFFSET(gpio);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pc->irq_lock[bank], flags);
+	bcm2835_gpio_irq_config(pc, gpio, false);
+	clear_bit(offset, &pc->enabled_irq_map[bank]);
+	spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
+}
+
+static int __bcm2835_gpio_irq_set_type_disabled(struct bcm2835_pinctrl *pc,
+	unsigned offset, unsigned int type)
+{
+	switch (type) {
+	case IRQ_TYPE_NONE:
+	case IRQ_TYPE_EDGE_RISING:
+	case IRQ_TYPE_EDGE_FALLING:
+	case IRQ_TYPE_EDGE_BOTH:
+	case IRQ_TYPE_LEVEL_HIGH:
+	case IRQ_TYPE_LEVEL_LOW:
+		pc->irq_type[offset] = type;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/* slower path for reconfiguring IRQ type */
+static int __bcm2835_gpio_irq_set_type_enabled(struct bcm2835_pinctrl *pc,
+	unsigned offset, unsigned int type)
+{
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		if (pc->irq_type[offset] != type) {
+			bcm2835_gpio_irq_config(pc, offset, false);
+			pc->irq_type[offset] = type;
+		}
+		break;
+
+	case IRQ_TYPE_EDGE_RISING:
+		if (pc->irq_type[offset] == IRQ_TYPE_EDGE_BOTH) {
+			/* RISING already enabled, disable FALLING */
+			pc->irq_type[offset] = IRQ_TYPE_EDGE_FALLING;
+			bcm2835_gpio_irq_config(pc, offset, false);
+			pc->irq_type[offset] = type;
+		} else if (pc->irq_type[offset] != type) {
+			bcm2835_gpio_irq_config(pc, offset, false);
+			pc->irq_type[offset] = type;
+			bcm2835_gpio_irq_config(pc, offset, true);
+		}
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		if (pc->irq_type[offset] == IRQ_TYPE_EDGE_BOTH) {
+			/* FALLING already enabled, disable RISING */
+			pc->irq_type[offset] = IRQ_TYPE_EDGE_RISING;
+			bcm2835_gpio_irq_config(pc, offset, false);
+			pc->irq_type[offset] = type;
+		} else if (pc->irq_type[offset] != type) {
+			bcm2835_gpio_irq_config(pc, offset, false);
+			pc->irq_type[offset] = type;
+			bcm2835_gpio_irq_config(pc, offset, true);
+		}
+		break;
+
+	case IRQ_TYPE_EDGE_BOTH:
+		if (pc->irq_type[offset] == IRQ_TYPE_EDGE_RISING) {
+			/* RISING already enabled, enable FALLING too */
+			pc->irq_type[offset] = IRQ_TYPE_EDGE_FALLING;
+			bcm2835_gpio_irq_config(pc, offset, true);
+			pc->irq_type[offset] = type;
+		} else if (pc->irq_type[offset] == IRQ_TYPE_EDGE_FALLING) {
+			/* FALLING already enabled, enable RISING too */
+			pc->irq_type[offset] = IRQ_TYPE_EDGE_RISING;
+			bcm2835_gpio_irq_config(pc, offset, true);
+			pc->irq_type[offset] = type;
+		} else if (pc->irq_type[offset] != type) {
+			bcm2835_gpio_irq_config(pc, offset, false);
+			pc->irq_type[offset] = type;
+			bcm2835_gpio_irq_config(pc, offset, true);
+		}
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+	case IRQ_TYPE_LEVEL_LOW:
+		if (pc->irq_type[offset] != type) {
+			bcm2835_gpio_irq_config(pc, offset, false);
+			pc->irq_type[offset] = type;
+			bcm2835_gpio_irq_config(pc, offset, true);
+		}
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int bcm2835_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+	struct bcm2835_pinctrl *pc = irq_data_get_irq_chip_data(data);
+	unsigned gpio = irqd_to_hwirq(data);
+	unsigned offset = GPIO_REG_SHIFT(gpio);
+	unsigned bank = GPIO_REG_OFFSET(gpio);
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&pc->irq_lock[bank], flags);
+
+	if (test_bit(offset, &pc->enabled_irq_map[bank]))
+		ret = __bcm2835_gpio_irq_set_type_enabled(pc, gpio, type);
+	else
+		ret = __bcm2835_gpio_irq_set_type_disabled(pc, gpio, type);
+
+	spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
+
+	return ret;
+}
+
+static struct irq_chip bcm2835_gpio_irq_chip = {
+	.name = MODULE_NAME,
+	.irq_enable = bcm2835_gpio_irq_enable,
+	.irq_disable = bcm2835_gpio_irq_disable,
+	.irq_set_type = bcm2835_gpio_irq_set_type,
+};
+
+static int bcm2835_pctl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	return ARRAY_SIZE(bcm2835_gpio_groups);
+}
+
+static const char *bcm2835_pctl_get_group_name(struct pinctrl_dev *pctldev,
+		unsigned selector)
+{
+	return bcm2835_gpio_groups[selector];
+}
+
+static int bcm2835_pctl_get_group_pins(struct pinctrl_dev *pctldev,
+		unsigned selector,
+		const unsigned **pins,
+		unsigned *num_pins)
+{
+	*pins = &bcm2835_gpio_pins[selector].number;
+	*num_pins = 1;
+
+	return 0;
+}
+
+static void bcm2835_pctl_pin_dbg_show(struct pinctrl_dev *pctldev,
+		struct seq_file *s,
+		unsigned offset)
+{
+	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+	enum bcm2835_fsel fsel = bcm2835_pinctrl_fsel_get(pc, offset);
+	const char *fname = bcm2835_functions[fsel];
+	int value = bcm2835_gpio_get_bit(pc, GPLEV0, offset);
+	int irq = irq_find_mapping(pc->irq_domain, offset);
+
+	seq_printf(s, "function %s in %s; irq %d (%s)",
+		fname, value ? "hi" : "lo",
+		irq, irq_type_names[pc->irq_type[offset]]);
+}
+
+static void bcm2835_pctl_dt_free_map(struct pinctrl_dev *pctldev,
+		struct pinctrl_map *maps, unsigned num_maps)
+{
+	int i;
+
+	for (i = 0; i < num_maps; i++)
+		if (maps[i].type == PIN_MAP_TYPE_CONFIGS_PIN)
+			kfree(maps[i].data.configs.configs);
+
+	kfree(maps);
+}
+
+static int bcm2835_pctl_dt_node_to_map_func(struct bcm2835_pinctrl *pc,
+		struct device_node *np, u32 pin, u32 fnum,
+		struct pinctrl_map **maps)
+{
+	struct pinctrl_map *map = *maps;
+
+	if (fnum >= ARRAY_SIZE(bcm2835_functions)) {
+		dev_err(pc->dev, "%s: invalid brcm,function %d\n",
+			of_node_full_name(np), fnum);
+		return -EINVAL;
+	}
+
+	map->type = PIN_MAP_TYPE_MUX_GROUP;
+	map->data.mux.group = bcm2835_gpio_groups[pin];
+	map->data.mux.function = bcm2835_functions[fnum];
+	(*maps)++;
+
+	return 0;
+}
+
+static int bcm2835_pctl_dt_node_to_map_pull(struct bcm2835_pinctrl *pc,
+		struct device_node *np, u32 pin, u32 pull,
+		struct pinctrl_map **maps)
+{
+	struct pinctrl_map *map = *maps;
+	unsigned long *configs;
+
+	if (pull > 2) {
+		dev_err(pc->dev, "%s: invalid brcm,pull %d\n",
+			of_node_full_name(np), pull);
+		return -EINVAL;
+	}
+
+	configs = kzalloc(sizeof(*configs), GFP_KERNEL);
+	if (!configs)
+		return -ENOMEM;
+	configs[0] = BCM2835_PINCONF_PACK(BCM2835_PINCONF_PARAM_PULL, pull);
+
+	map->type = PIN_MAP_TYPE_CONFIGS_PIN;
+	map->data.configs.group_or_pin = bcm2835_gpio_pins[pin].name;
+	map->data.configs.configs = configs;
+	map->data.configs.num_configs = 1;
+	(*maps)++;
+
+	return 0;
+}
+
+static inline u32 prop_u32(struct property *p, int i)
+{
+	return be32_to_cpup(((__be32 *)p->value) + i);
+}
+
+static int bcm2835_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
+		struct device_node *np,
+		struct pinctrl_map **map, unsigned *num_maps)
+{
+	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+	struct property *pins, *funcs, *pulls;
+	int num_pins, num_funcs, num_pulls, maps_per_pin;
+	struct pinctrl_map *maps, *cur_map;
+	int i, err;
+	u32 pin, func, pull;
+
+	pins = of_find_property(np, "brcm,pins", NULL);
+	if (!pins) {
+		dev_err(pc->dev, "%s: missing brcm,pins property\n",
+				of_node_full_name(np));
+		return -EINVAL;
+	}
+
+	funcs = of_find_property(np, "brcm,function", NULL);
+	pulls = of_find_property(np, "brcm,pull", NULL);
+
+	if (!funcs && !pulls) {
+		dev_err(pc->dev,
+			"%s: neither brcm,function nor brcm,pull specified\n",
+			of_node_full_name(np));
+		return -EINVAL;
+	}
+
+	num_pins = pins->length / 4;
+	num_funcs = funcs ? (funcs->length / 4) : 0;
+	num_pulls = pulls ? (pulls->length / 4) : 0;
+
+	if (num_funcs > 1 && num_funcs != num_pins) {
+		dev_err(pc->dev,
+			"%s: brcm,function must have 1 or %d entries\n",
+			of_node_full_name(np), num_pins);
+		return -EINVAL;
+	}
+
+	if (num_pulls > 1 && num_pulls != num_pins) {
+		dev_err(pc->dev,
+			"%s: brcm,pull must have 1 or %d entries\n",
+			of_node_full_name(np), num_pins);
+		return -EINVAL;
+	}
+
+	maps_per_pin = 0;
+	if (num_funcs)
+		maps_per_pin++;
+	if (num_pulls)
+		maps_per_pin++;
+	cur_map = maps = kzalloc(num_pins * maps_per_pin * sizeof(*maps),
+				GFP_KERNEL);
+	if (!maps)
+		return -ENOMEM;
+
+	for (i = 0; i < num_pins; i++) {
+		pin = prop_u32(pins, i);
+		if (pin >= ARRAY_SIZE(bcm2835_gpio_pins)) {
+			dev_err(pc->dev, "%s: invalid brcm,pins value %d\n",
+				of_node_full_name(np), pin);
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (num_funcs) {
+			func = prop_u32(funcs, (num_funcs > 1) ? i : 0);
+			err = bcm2835_pctl_dt_node_to_map_func(pc, np, pin,
+							func, &cur_map);
+			if (err)
+				goto out;
+		}
+		if (num_pulls) {
+			pull = prop_u32(pulls, (num_pulls > 1) ? i : 0);
+			err = bcm2835_pctl_dt_node_to_map_pull(pc, np, pin,
+							pull, &cur_map);
+			if (err)
+				goto out;
+		}
+	}
+
+	*map = maps;
+	*num_maps = num_pins * maps_per_pin;
+
+	return 0;
+
+out:
+	kfree(maps);
+	return err;
+}
+
+static struct pinctrl_ops bcm2835_pctl_ops = {
+	.get_groups_count = bcm2835_pctl_get_groups_count,
+	.get_group_name = bcm2835_pctl_get_group_name,
+	.get_group_pins = bcm2835_pctl_get_group_pins,
+	.pin_dbg_show = bcm2835_pctl_pin_dbg_show,
+	.dt_node_to_map = bcm2835_pctl_dt_node_to_map,
+	.dt_free_map = bcm2835_pctl_dt_free_map,
+};
+
+static int bcm2835_pmx_get_functions_count(struct pinctrl_dev *pctldev)
+{
+	return BCM2835_FSEL_COUNT;
+}
+
+static const char *bcm2835_pmx_get_function_name(struct pinctrl_dev *pctldev,
+		unsigned selector)
+{
+	return bcm2835_functions[selector];
+}
+
+static int bcm2835_pmx_get_function_groups(struct pinctrl_dev *pctldev,
+		unsigned selector,
+		const char * const **groups,
+		unsigned * const num_groups)
+{
+	/* every pin can do every function */
+	*groups = bcm2835_gpio_groups;
+	*num_groups = ARRAY_SIZE(bcm2835_gpio_groups);
+
+	return 0;
+}
+
+static int bcm2835_pmx_enable(struct pinctrl_dev *pctldev,
+		unsigned func_selector,
+		unsigned group_selector)
+{
+	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+
+	bcm2835_pinctrl_fsel_set(pc, group_selector, func_selector);
+
+	return 0;
+}
+
+static void bcm2835_pmx_disable(struct pinctrl_dev *pctldev,
+		unsigned func_selector,
+		unsigned group_selector)
+{
+	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+
+	/* disable by setting to GPIO_IN */
+	bcm2835_pinctrl_fsel_set(pc, group_selector, BCM2835_FSEL_GPIO_IN);
+}
+
+static void bcm2835_pmx_gpio_disable_free(struct pinctrl_dev *pctldev,
+		struct pinctrl_gpio_range *range,
+		unsigned offset)
+{
+	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+
+	/* disable by setting to GPIO_IN */
+	bcm2835_pinctrl_fsel_set(pc, offset, BCM2835_FSEL_GPIO_IN);
+}
+
+static int bcm2835_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
+		struct pinctrl_gpio_range *range,
+		unsigned offset,
+		bool input)
+{
+	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+	enum bcm2835_fsel fsel = input ?
+		BCM2835_FSEL_GPIO_IN : BCM2835_FSEL_GPIO_OUT;
+
+	bcm2835_pinctrl_fsel_set(pc, offset, fsel);
+
+	return 0;
+}
+
+static struct pinmux_ops bcm2835_pmx_ops = {
+	.get_functions_count = bcm2835_pmx_get_functions_count,
+	.get_function_name = bcm2835_pmx_get_function_name,
+	.get_function_groups = bcm2835_pmx_get_function_groups,
+	.enable = bcm2835_pmx_enable,
+	.disable = bcm2835_pmx_disable,
+	.gpio_disable_free = bcm2835_pmx_gpio_disable_free,
+	.gpio_set_direction = bcm2835_pmx_gpio_set_direction,
+};
+
+static int bcm2835_pinconf_get(struct pinctrl_dev *pctldev,
+			unsigned pin, unsigned long *config)
+{
+	/* No way to read back config in HW */
+	return -ENOTSUPP;
+}
+
+static int bcm2835_pinconf_set(struct pinctrl_dev *pctldev,
+			unsigned pin, unsigned long config)
+{
+	struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
+	enum bcm2835_pinconf_param param = BCM2835_PINCONF_UNPACK_PARAM(config);
+	u16 arg = BCM2835_PINCONF_UNPACK_ARG(config);
+	u32 off, bit;
+
+	if (param != BCM2835_PINCONF_PARAM_PULL)
+		return -EINVAL;
+
+	off = GPIO_REG_OFFSET(pin);
+	bit = GPIO_REG_SHIFT(pin);
+
+	bcm2835_gpio_wr(pc, GPPUD, arg & 3);
+	/*
+	 * Docs say to wait 150 cycles, but not of what. We assume a
+	 * 1 MHz clock here, which is pretty slow...
+	 */
+	udelay(150);
+	bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), BIT(bit));
+	udelay(150);
+	bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), 0);
+
+	return 0;
+}
+
+struct pinconf_ops bcm2835_pinconf_ops = {
+	.pin_config_get = bcm2835_pinconf_get,
+	.pin_config_set = bcm2835_pinconf_set,
+};
+
+static struct pinctrl_desc bcm2835_pinctrl_desc = {
+	.name = MODULE_NAME,
+	.pins = bcm2835_gpio_pins,
+	.npins = ARRAY_SIZE(bcm2835_gpio_pins),
+	.pctlops = &bcm2835_pctl_ops,
+	.pmxops = &bcm2835_pmx_ops,
+	.confops = &bcm2835_pinconf_ops,
+	.owner = THIS_MODULE,
+};
+
+static struct pinctrl_gpio_range bcm2835_pinctrl_gpio_range __devinitconst = {
+	.name = MODULE_NAME,
+	.npins = BCM2835_NUM_GPIOS,
+};
+
+static int __devinit bcm2835_pinctrl_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct bcm2835_pinctrl *pc;
+	struct resource iomem;
+	int err, i;
+	BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_pins) != BCM2835_NUM_GPIOS);
+	BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_groups) != BCM2835_NUM_GPIOS);
+
+	pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, pc);
+	pc->dev = dev;
+
+	err = of_address_to_resource(np, 0, &iomem);
+	if (err) {
+		dev_err(dev, "could not get IO memory\n");
+		return err;
+	}
+
+	pc->base = devm_request_and_ioremap(&pdev->dev, &iomem);
+	if (!pc->base)
+		return -EADDRNOTAVAIL;
+
+	pc->gpio_chip = bcm2835_gpio_chip;
+	pc->gpio_chip.dev = dev;
+	pc->gpio_chip.of_node = np;
+
+	pc->irq_domain = irq_domain_add_linear(np, BCM2835_NUM_GPIOS,
+			&irq_domain_simple_ops, NULL);
+	if (!pc->irq_domain) {
+		dev_err(dev, "could not create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < BCM2835_NUM_GPIOS; i++) {
+		int irq = irq_create_mapping(pc->irq_domain, i);
+		irq_set_lockdep_class(irq, &gpio_lock_class);
+		irq_set_chip_and_handler(irq, &bcm2835_gpio_irq_chip,
+				handle_simple_irq);
+		irq_set_chip_data(irq, pc);
+		set_irq_flags(irq, IRQF_VALID);
+	}
+
+	for (i = 0; i < BCM2835_NUM_BANKS; i++) {
+		unsigned long events;
+		unsigned offset;
+		int len;
+		char *name;
+
+		/* clear event detection flags */
+		bcm2835_gpio_wr(pc, GPREN0 + i * 4, 0);
+		bcm2835_gpio_wr(pc, GPFEN0 + i * 4, 0);
+		bcm2835_gpio_wr(pc, GPHEN0 + i * 4, 0);
+		bcm2835_gpio_wr(pc, GPLEN0 + i * 4, 0);
+		bcm2835_gpio_wr(pc, GPAREN0 + i * 4, 0);
+		bcm2835_gpio_wr(pc, GPAFEN0 + i * 4, 0);
+
+		/* clear all the events */
+		events = bcm2835_gpio_rd(pc, GPEDS0 + i * 4);
+		for_each_set_bit(offset, &events, 32)
+			bcm2835_gpio_wr(pc, GPEDS0 + i * 4, BIT(offset));
+
+		pc->irq[i] = irq_of_parse_and_map(np, i);
+		pc->irq_data[i].pc = pc;
+		pc->irq_data[i].bank = i;
+		spin_lock_init(&pc->irq_lock[i]);
+
+		len = strlen(dev_name(pc->dev)) + 16;
+		name = devm_kzalloc(pc->dev, len, GFP_KERNEL);
+		if (!name)
+			return -ENOMEM;
+		snprintf(name, len, "%s:bank%d", dev_name(pc->dev), i);
+
+		err = devm_request_irq(dev, pc->irq[i],
+			bcm2835_gpio_irq_handler, IRQF_SHARED,
+			name, &pc->irq_data[i]);
+		if (err) {
+			dev_err(dev, "unable to request IRQ %d\n", pc->irq[i]);
+			return err;
+		}
+	}
+
+	err = gpiochip_add(&pc->gpio_chip);
+	if (err) {
+		dev_err(dev, "could not add GPIO chip\n");
+		return err;
+	}
+
+	pc->pctl_dev = pinctrl_register(&bcm2835_pinctrl_desc, dev, pc);
+	if (!pc->pctl_dev) {
+		gpiochip_remove(&pc->gpio_chip);
+		return PTR_ERR(pc->pctl_dev);
+	}
+
+	pc->gpio_range = bcm2835_pinctrl_gpio_range;
+	pc->gpio_range.base = pc->gpio_chip.base;
+	pc->gpio_range.gc = &pc->gpio_chip;
+	pinctrl_add_gpio_range(pc->pctl_dev, &pc->gpio_range);
+
+	return 0;
+}
+
+static int __devexit bcm2835_pinctrl_remove(struct platform_device *pdev)
+{
+	struct bcm2835_pinctrl *pc = platform_get_drvdata(pdev);
+
+	pinctrl_unregister(pc->pctl_dev);
+	gpiochip_remove(&pc->gpio_chip);
+
+	return 0;
+}
+
+static struct of_device_id bcm2835_pinctrl_match[] __devinitconst = {
+	{ .compatible = "brcm,bcm2835-gpio" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, bcm2835_pinctrl_match);
+
+static struct platform_driver bcm2835_pinctrl_driver = {
+	.probe = bcm2835_pinctrl_probe,
+	.remove = bcm2835_pinctrl_remove,
+	.driver = {
+		.name = MODULE_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = bcm2835_pinctrl_match,
+	},
+};
+module_platform_driver(bcm2835_pinctrl_driver);
+
+MODULE_AUTHOR("Chris Boot, Simon Arlott, Stephen Warren");
+MODULE_DESCRIPTION("BCM2835 Pin control driver");
+MODULE_LICENSE("GPL");