gpio: mvebu: new gpio driver for mvebu platforms

gpio: mvebu: new gpio driver for mvebu platforms

[Thomas Petazzoni]

Hello,

This patch set adds a new GPIO driver for Marvell EBU SoCs, which aims
at replacing the existing GPIO driver from plat-orion/gpio.c. The
driver comes with the necessary DT changes to make it work on Armada
370 and Armada XP, and it has been tested successfully by Sebastian
Hesselbarth on Dove. It should also work flawlessly on other Marvell
EBU SoCs (Kirkwood, Orion, Discovery), but this remains to be tested
by the relevant maintainers.

This new driver reuses a lot of code from the existing
plat-orion/gpio.c driver, but has a number of advantages:

 *) Support for Armada 370 and Armada XP
 *) It is integrated with the mvebu pinctrl driver so that GPIO pins
    are properly muxed, and the GPIO driver knows which GPIO pins are
    output-only or input-only. This driver has been submitted by
    Sebastian Hesselbarth today on the LAKML.
 *) Properly placed in drivers/gpio
 *) More extensible mechanism to support platform differences. The
    plat-orion driver uses a simple mask-offset DT property, which
    works fine for Discovery MV78200 but not for Armada XP. The new
    driver uses different compatible strings to identify the different
    variants of the GPIO controllers.

Thanks,

Thomas

The following changes since commit 872b6be95abf9d57e0639d0345fa2b5a0e4fa0f4:

  arm: mvebu: add pinctrl support in defconfig (2012-08-11 11:27:33 +0200)

are available in the git repository at:

  git://github.com/MISL-EBU-System-SW/mainline-public.git mvebu-gpio

for you to fetch changes up to 92dffc2d360b84d154ffdc049346d5011592bc7f:

  arm: mvebu: add gpio support in defconfig (2012-08-11 15:20:55 +0200)

----------------------------------------------------------------
Thomas Petazzoni (5):
      gpio: introduce gpio-mvebu driver for Marvell SoCs
      Documentation: add description of DT binding for the gpio-mvebu driver
      arm: mvebu: use GPIO support now that a driver is available
      arm: mvebu: add DT information for GPIO banks on Armada 370 and XP
      arm: mvebu: add gpio support in defconfig

 .../devicetree/bindings/gpio/gpio-mvebu.txt        |   44 ++
 arch/arm/Kconfig                                   |    1 +
 arch/arm/boot/dts/armada-370.dtsi                  |   30 +
 arch/arm/boot/dts/armada-xp-mv78230.dtsi           |   22 +
 arch/arm/boot/dts/armada-xp-mv78260.dtsi           |   33 +
 arch/arm/boot/dts/armada-xp-mv78460.dtsi           |   33 +
 arch/arm/configs/mvebu_defconfig                   |    2 +
 arch/arm/mach-mvebu/include/mach/gpio.h            |    1 +
 drivers/gpio/Kconfig                               |    6 +
 drivers/gpio/Makefile                              |    1 +
 drivers/gpio/gpio-mvebu.c                          |  650 ++++++++++++++++++++
 11 files changed, 823 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
 create mode 100644 arch/arm/mach-mvebu/include/mach/gpio.h
 create mode 100644 drivers/gpio/gpio-mvebu.c

[PATCH 1/5] gpio: introduce gpio-mvebu driver for Marvell SoCs

[Thomas Petazzoni]

This driver aims at replacing the arch/arm/plat-orion/gpio.c driver,
and is designed to be compatible with all Marvell EBU SoCs: Orion,
Kirkwood, Dove, Armada 370/XP and Discovery.

It has been successfully tested on Dove and Armada XP at the moment.

Compared to the plat-orion driver, this new driver has the following
added benefits:

 *) Support for Armada 370 and Armada XP
 *) It is integrated with the mvebu pinctrl driver so that GPIO pins
    are properly muxed, and the GPIO driver knows which GPIO pins are
    output-only or input-only.
 *) Properly placed in drivers/gpio
 *) More extensible mechanism to support platform differences. The
    plat-orion driver uses a simple mask-offset DT property, which
    works fine for Discovery MV78200 but not for Armada XP. The new
    driver uses different compatible strings to identify the different
    variants of the GPIO controllers.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
---
 drivers/gpio/Kconfig      |    6 +
 drivers/gpio/Makefile     |    1 +
 drivers/gpio/gpio-mvebu.c |  650 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 657 insertions(+)
 create mode 100644 drivers/gpio/gpio-mvebu.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b16c8a7..993b0c4 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -150,6 +150,12 @@ config GPIO_MSM_V2
 	  Qualcomm MSM chips.  Most of the pins on the MSM can be
 	  selected for GPIO, and are controlled by this driver.
 
+config GPIO_MVEBU
+	def_bool y
+	depends on ARCH_MVEBU
+	select GPIO_GENERIC
+	select GENERIC_IRQ_CHIP
+
 config GPIO_MXC
 	def_bool y
 	depends on ARCH_MXC
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 153cace..1a33e67 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_GPIO_MPC8XXX)	+= gpio-mpc8xxx.o
 obj-$(CONFIG_GPIO_MSIC)		+= gpio-msic.o
 obj-$(CONFIG_GPIO_MSM_V1)	+= gpio-msm-v1.o
 obj-$(CONFIG_GPIO_MSM_V2)	+= gpio-msm-v2.o
+obj-$(CONFIG_GPIO_MVEBU)        += gpio-mvebu.o
 obj-$(CONFIG_GPIO_MXC)		+= gpio-mxc.o
 obj-$(CONFIG_GPIO_MXS)		+= gpio-mxs.o
 obj-$(CONFIG_ARCH_OMAP)		+= gpio-omap.o
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
new file mode 100644
index 0000000..d008e55
--- /dev/null
+++ b/drivers/gpio/gpio-mvebu.c
@@ -0,0 +1,650 @@
+/*
+ * GPIO driver for Marvell SoCs
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ * Andrew Lunn <andrew@lunn.ch>
+ * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * This driver is a fairly straightforward GPIO driver for the
+ * complete family of Marvell EBU SoC platforms (Orion, Dove,
+ * Kirkwood, Discovery, Armada 370/XP). The only complexity of this
+ * driver is the different register layout that exists between the
+ * non-SMP platforms (Orion, Dove, Kirkwood, Armada 370) and the SMP
+ * platforms (MV78200 from the Discovery family and the Armada
+ * XP). Therefore, this driver handles three variants of the GPIO
+ * block:
+ * - the basic variant, called "orion-gpio", with the simplest
+ *   register set. Used on Orion, Dove, Kirkwoord, Armada 370 and
+ *   non-SMP Discovery systems
+ * - the mv78200 variant for MV78200 Discovery systems. This variant
+ *   turns the edge mask and level mask registers into CPU0 edge
+ *   mask/level mask registers, and adds CPU1 edge mask/level mask
+ *   registers.
+ * - the armadaxp variant for Armada XP systems. This variant keeps
+ *   the normal cause/edge mask/level mask registers when the global
+ *   interrupts are used, but adds per-CPU cause/edge mask/level mask
+ *   registers n a separate memory area for the per-CPU GPIO
+ *   interrupts.
+ */
+
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/irqdomain.h>
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pinctrl/consumer.h>
+
+/*
+ * GPIO unit register offsets.
+ */
+#define GPIO_OUT_OFF		0x0000
+#define GPIO_IO_CONF_OFF	0x0004
+#define GPIO_BLINK_EN_OFF	0x0008
+#define GPIO_IN_POL_OFF		0x000c
+#define GPIO_DATA_IN_OFF	0x0010
+#define GPIO_EDGE_CAUSE_OFF	0x0014
+#define GPIO_EDGE_MASK_OFF	0x0018
+#define GPIO_LEVEL_MASK_OFF	0x001c
+
+/* The MV78200 has per-CPU registers for edge mask and level mask */
+#define GPIO_EDGE_MASK_MV78200_OFF(cpu)   ((cpu) ? 0x30 : 0x18)
+#define GPIO_LEVEL_MASK_MV78200_OFF(cpu)  ((cpu) ? 0x34 : 0x1C)
+
+/* The Armada XP has per-CPU registers for interrupt cause, interrupt
+ * mask and interrupt level mask. Those are relative to the
+ * percpu_membase. */
+#define GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu) ((cpu) * 0x4)
+#define GPIO_EDGE_MASK_ARMADAXP_OFF(cpu)  (0x10 + (cpu) * 0x4)
+#define GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu) (0x20 + (cpu) * 0x4)
+
+#define MVEBU_GPIO_SOC_VARIANT_ORION    0x1
+#define MVEBU_GPIO_SOC_VARIANT_MV78200  0x2
+#define MVEBU_GPIO_SOC_VARIANT_ARMADAXP 0x3
+
+struct mvebu_gpio_chip {
+	struct gpio_chip   chip;
+	spinlock_t	   lock;
+	void __iomem	  *membase;
+	void __iomem	  *percpu_membase;
+	unsigned int       irqbase;
+	struct irq_domain *domain;
+	int                soc_variant;
+};
+
+/*
+ * Common functions to all SoCs
+ */
+static void __iomem *GPIO_OUT(struct mvebu_gpio_chip *mvchip)
+{
+	return mvchip->membase + GPIO_OUT_OFF;
+}
+
+static void __iomem *GPIO_IO_CONF(struct mvebu_gpio_chip *mvchip)
+{
+	return mvchip->membase + GPIO_IO_CONF_OFF;
+}
+
+static void __iomem *GPIO_IN_POL(struct mvebu_gpio_chip *mvchip)
+{
+	return mvchip->membase + GPIO_IN_POL_OFF;
+}
+
+static void __iomem *GPIO_DATA_IN(struct mvebu_gpio_chip *mvchip)
+{
+	return mvchip->membase + GPIO_DATA_IN_OFF;
+}
+
+static void __iomem *GPIO_EDGE_CAUSE(struct mvebu_gpio_chip *mvchip)
+{
+	int cpu;
+
+	switch(mvchip->soc_variant) {
+	case MVEBU_GPIO_SOC_VARIANT_ORION:
+	case MVEBU_GPIO_SOC_VARIANT_MV78200:
+		return mvchip->membase + GPIO_EDGE_CAUSE_OFF;
+	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
+		cpu = smp_processor_id();
+		return mvchip->percpu_membase + GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu);
+	default:
+		BUG();
+	}
+}
+
+static void __iomem *GPIO_EDGE_MASK(struct mvebu_gpio_chip *mvchip)
+{
+	int cpu;
+
+	switch(mvchip->soc_variant) {
+	case MVEBU_GPIO_SOC_VARIANT_ORION:
+		return mvchip->membase + GPIO_EDGE_MASK_OFF;
+	case MVEBU_GPIO_SOC_VARIANT_MV78200:
+		cpu = smp_processor_id();
+		return mvchip->membase + GPIO_EDGE_MASK_MV78200_OFF(cpu);
+	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
+		cpu = smp_processor_id();
+		return mvchip->percpu_membase + GPIO_EDGE_MASK_ARMADAXP_OFF(cpu);
+	default:
+		BUG();
+	}
+}
+
+static void __iomem *GPIO_LEVEL_MASK(struct mvebu_gpio_chip *mvchip)
+{
+	int cpu;
+
+	switch(mvchip->soc_variant) {
+	case MVEBU_GPIO_SOC_VARIANT_ORION:
+		return mvchip->membase + GPIO_LEVEL_MASK_OFF;
+	case MVEBU_GPIO_SOC_VARIANT_MV78200:
+		cpu = smp_processor_id();
+		return mvchip->membase + GPIO_LEVEL_MASK_MV78200_OFF(cpu);
+	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
+		cpu = smp_processor_id();
+		return mvchip->percpu_membase + GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu);
+	default:
+		BUG();
+	}
+}
+
+int mvebu_gpio_request(struct gpio_chip *chip, unsigned pin)
+{
+	return pinctrl_request_gpio(chip->base + pin);
+}
+
+void mvebu_gpio_free(struct gpio_chip *chip, unsigned pin)
+{
+	pinctrl_free_gpio(chip->base + pin);
+}
+
+static void mvebu_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
+{
+	struct mvebu_gpio_chip *mvchip =
+		container_of(chip, struct mvebu_gpio_chip, chip);
+	unsigned long flags;
+	u32 u;
+
+	spin_lock_irqsave(&mvchip->lock, flags);
+	u = readl(GPIO_OUT(mvchip));
+	if (value)
+		u |= 1 << pin;
+	else
+		u &= ~(1 << pin);
+	writel(u, GPIO_OUT(mvchip));
+	spin_unlock_irqrestore(&mvchip->lock, flags);
+}
+
+static int mvebu_gpio_get(struct gpio_chip *chip, unsigned pin)
+{
+	struct mvebu_gpio_chip *mvchip =
+		container_of(chip, struct mvebu_gpio_chip, chip);
+	u32 u;
+
+	if (readl(GPIO_IO_CONF(mvchip)) & (1 << pin)) {
+		u = readl(GPIO_DATA_IN(mvchip)) ^ readl(GPIO_IN_POL(mvchip));
+	} else {
+		u = readl(GPIO_OUT(mvchip));
+	}
+
+	return (u >> pin) & 1;
+}
+
+static int mvebu_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
+{
+	struct mvebu_gpio_chip *mvchip =
+		container_of(chip, struct mvebu_gpio_chip, chip);
+	unsigned long flags;
+	int ret;
+	u32 u;
+
+	/* Check with the pinctrl driver whether this pin is usable as
+	 * an input GPIO */
+	ret = pinctrl_gpio_direction_input(chip->base + pin);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&mvchip->lock, flags);
+	u = readl(GPIO_IO_CONF(mvchip));
+	u |= 1 << pin;
+	writel(u, GPIO_IO_CONF(mvchip));
+	spin_unlock_irqrestore(&mvchip->lock, flags);
+
+	return 0;
+}
+
+static int mvebu_gpio_direction_output(struct gpio_chip *chip, unsigned pin,
+				       int value)
+{
+	struct mvebu_gpio_chip *mvchip =
+		container_of(chip, struct mvebu_gpio_chip, chip);
+	unsigned long flags;
+	int ret;
+	u32 u;
+
+	/* Check with the pinctrl driver whether this pin is usable as
+	 * an output GPIO */
+	ret = pinctrl_gpio_direction_output(chip->base + pin);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&mvchip->lock, flags);
+	u = readl(GPIO_IO_CONF(mvchip));
+	u &= ~(1 << pin);
+	writel(u, GPIO_IO_CONF(mvchip));
+	spin_unlock_irqrestore(&mvchip->lock, flags);
+
+	return 0;
+}
+
+static int mvebu_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
+{
+	struct mvebu_gpio_chip *mvchip =
+		container_of(chip, struct mvebu_gpio_chip, chip);
+	return irq_create_mapping(mvchip->domain, pin);
+}
+
+static void mvebu_gpio_irq_ack(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct mvebu_gpio_chip *mvchip = gc->private;
+	u32 mask = ~(1 << (d->irq - gc->irq_base));
+
+	irq_gc_lock(gc);
+	writel(mask, GPIO_EDGE_CAUSE(mvchip));
+	irq_gc_unlock(gc);
+}
+
+static void mvebu_gpio_edge_irq_mask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct mvebu_gpio_chip *mvchip = gc->private;
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	gc->mask_cache &= ~mask;
+	writel(gc->mask_cache, GPIO_EDGE_MASK(mvchip));
+	irq_gc_unlock(gc);
+}
+
+static void mvebu_gpio_edge_irq_unmask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct mvebu_gpio_chip *mvchip = gc->private;
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	gc->mask_cache |= mask;
+	writel(gc->mask_cache, GPIO_EDGE_MASK(mvchip));
+	irq_gc_unlock(gc);
+}
+
+static void mvebu_gpio_level_irq_mask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct mvebu_gpio_chip *mvchip = gc->private;
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	gc->mask_cache &= ~mask;
+	writel(gc->mask_cache, GPIO_LEVEL_MASK(mvchip));
+	irq_gc_unlock(gc);
+}
+
+static void mvebu_gpio_level_irq_unmask(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct mvebu_gpio_chip *mvchip = gc->private;
+	u32 mask = 1 << (d->irq - gc->irq_base);
+
+	irq_gc_lock(gc);
+	gc->mask_cache |= mask;
+	writel(gc->mask_cache, GPIO_LEVEL_MASK(mvchip));
+	irq_gc_unlock(gc);
+}
+
+/*****************************************************************************
+ * MVEBU GPIO IRQ
+ *
+ * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
+ * value of the line or the opposite value.
+ *
+ * Level IRQ handlers: DATA_IN is used directly as cause register.
+ *                     Interrupt are masked by LEVEL_MASK registers.
+ * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
+ *                     Interrupt are masked by EDGE_MASK registers.
+ * Both-edge handlers: Similar to regular Edge handlers, but also swaps
+ *                     the polarity to catch the next line transaction.
+ *                     This is a race condition that might not perfectly
+ *                     work on some use cases.
+ *
+ * Every eight GPIO lines are grouped (OR'ed) before going up to main
+ * cause register.
+ *
+ *                    EDGE  cause    mask
+ *        data-in   /--------| |-----| |----\
+ *     -----| |-----                         ---- to main cause reg
+ *           X      \----------------| |----/
+ *        polarity    LEVEL          mask
+ *
+ ****************************************************************************/
+
+static int mvebu_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+	struct mvebu_gpio_chip *mvchip = gc->private;
+	int pin;
+	u32 u;
+
+	pin = d->hwirq - mvchip->irqbase;
+
+	u = readl(GPIO_IO_CONF(mvchip)) & (1 << pin);
+	if (!u) {
+		return -EINVAL;
+	}
+
+	type &= IRQ_TYPE_SENSE_MASK;
+	if (type == IRQ_TYPE_NONE)
+		return -EINVAL;
+
+	/* Check if we need to change chip and handler */
+	if (!(ct->type & type))
+		if (irq_setup_alt_chip(d, type))
+			return -EINVAL;
+
+	/*
+	 * Configure interrupt polarity.
+	 */
+	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
+		u = readl(GPIO_IN_POL(mvchip));
+		u &= ~(1 << pin);
+		writel(u, GPIO_IN_POL(mvchip));
+	} else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
+		u = readl(GPIO_IN_POL(mvchip));
+		u |= 1 << pin;
+		writel(u, GPIO_IN_POL(mvchip));
+	} else if (type == IRQ_TYPE_EDGE_BOTH) {
+		u32 v;
+
+		v = readl(GPIO_IN_POL(mvchip)) ^ readl(GPIO_DATA_IN(mvchip));
+
+		/*
+		 * set initial polarity based on current input level
+		 */
+		u = readl(GPIO_IN_POL(mvchip));
+		if (v & (1 << pin))
+			u |= 1 << pin;		/* falling */
+		else
+			u &= ~(1 << pin);	/* rising */
+		writel(u, GPIO_IN_POL(mvchip));
+	}
+	return 0;
+}
+
+static void mvebu_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct mvebu_gpio_chip *mvchip = irq_get_handler_data(irq);
+	u32 cause, type;
+	int i;
+
+	if (mvchip == NULL)
+		return;
+
+	cause = readl(GPIO_DATA_IN(mvchip)) & readl(GPIO_LEVEL_MASK(mvchip));
+	cause |= readl(GPIO_EDGE_CAUSE(mvchip)) & readl(GPIO_EDGE_MASK(mvchip));
+
+	for (i = 0; i < mvchip->chip.ngpio; i++) {
+		int irq;
+
+		irq = mvchip->irqbase + i;
+
+		if (!(cause & (1 << i)))
+			continue;
+
+		type = irqd_get_trigger_type(irq_get_irq_data(irq));
+		if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
+			/* Swap polarity (race with GPIO line) */
+			u32 polarity;
+
+			polarity = readl(GPIO_IN_POL(mvchip));
+			polarity ^= 1 << i;
+			writel(polarity, GPIO_IN_POL(mvchip));
+		}
+		generic_handle_irq(irq);
+	}
+}
+
+static struct platform_device_id mvebu_gpio_ids[] = {
+	{
+		.name = "orion-gpio",
+	}, {
+		.name = "mv78200-gpio",
+	}, {
+		.name = "armadaxp-gpio",
+	}, {
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(platform, mvebu_gpio_ids);
+
+static struct of_device_id mvebu_gpio_of_match[] __devinitdata = {
+	{
+		.compatible = "marvell,orion-gpio",
+		.data       = (void*) MVEBU_GPIO_SOC_VARIANT_ORION,
+	},
+	{
+		.compatible = "marvell,mv78200-gpio",
+		.data       = (void*) MVEBU_GPIO_SOC_VARIANT_MV78200,
+	},
+	{
+		.compatible = "marvell,armadaxp-gpio",
+		.data       = (void*) MVEBU_GPIO_SOC_VARIANT_ARMADAXP,
+	},
+	{
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(of, mvebu_gpio_of_match);
+
+static unsigned int mvebu_gpio_chip_count;
+
+static int __devinit mvebu_gpio_probe(struct platform_device *pdev)
+{
+	struct mvebu_gpio_chip *mvchip;
+	const struct of_device_id *match;
+	struct device_node *np = pdev->dev.of_node;
+	struct resource *res;
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+	unsigned int ngpios;
+	int soc_variant;
+	int irqbase;
+	int i, cpu;
+
+	match = of_match_device(mvebu_gpio_of_match, &pdev->dev);
+	if (match)
+		soc_variant = (int) match->data;
+	else
+		soc_variant = MVEBU_GPIO_SOC_VARIANT_ORION;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (! res) {
+		dev_err(&pdev->dev, "Cannot get memory resource\n");
+		return -ENODEV;
+	}
+
+	mvchip = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_gpio_chip), GFP_KERNEL);
+	if (! mvchip){
+		dev_err(&pdev->dev, "Cannot allocate memory\n");
+		return -ENOMEM;
+	}
+
+	if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
+		dev_err(&pdev->dev, "Missing ngpios OF property\n");
+		return -ENODEV;
+	}
+
+	mvchip->soc_variant = soc_variant;
+	mvchip->chip.label = kasprintf(GFP_KERNEL, "mvebu-gpio%d", mvebu_gpio_chip_count);
+	mvchip->chip.dev = &pdev->dev;
+	mvchip->chip.request = mvebu_gpio_request;
+	mvchip->chip.direction_input = mvebu_gpio_direction_input;
+	mvchip->chip.get = mvebu_gpio_get;
+	mvchip->chip.direction_output = mvebu_gpio_direction_output;
+	mvchip->chip.set = mvebu_gpio_set;
+	mvchip->chip.to_irq = mvebu_gpio_to_irq;
+	mvchip->chip.base = mvebu_gpio_chip_count * 32;
+	mvchip->chip.ngpio = ngpios;
+	mvchip->chip.can_sleep = 0;
+#ifdef CONFIG_OF
+	mvchip->chip.of_node = np;
+#endif
+
+	spin_lock_init(&mvchip->lock);
+	mvchip->membase = devm_request_and_ioremap(&pdev->dev, res);
+	if (! mvchip->membase) {
+		dev_err(&pdev->dev, "Cannot ioremap\n");
+		kfree(mvchip->chip.label);
+		return -ENOMEM;
+	}
+
+	/* The Armada XP has a second range of registers for the
+	 * per-CPU registers */
+	if (soc_variant == MVEBU_GPIO_SOC_VARIANT_ARMADAXP) {
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		if (! res) {
+			dev_err(&pdev->dev, "Cannot get memory resource\n");
+			kfree(mvchip->chip.label);
+			return -ENODEV;
+		}
+
+		mvchip->percpu_membase = devm_request_and_ioremap(&pdev->dev, res);
+		if (! mvchip->percpu_membase) {
+			dev_err(&pdev->dev, "Cannot ioremap\n");
+			kfree(mvchip->chip.label);
+			return -ENOMEM;
+		}
+	}
+
+	/*
+	 * Mask and clear GPIO interrupts.
+	 */
+	switch(soc_variant) {
+	case MVEBU_GPIO_SOC_VARIANT_ORION:
+		writel(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
+		writel(0, mvchip->membase + GPIO_EDGE_MASK_OFF);
+		writel(0, mvchip->membase + GPIO_LEVEL_MASK_OFF);
+		break;
+	case MVEBU_GPIO_SOC_VARIANT_MV78200:
+		writel(0, GPIO_EDGE_CAUSE(mvchip));
+		for (cpu = 0; cpu < 2; cpu++) {
+			writel(0, mvchip->membase + GPIO_EDGE_MASK_MV78200_OFF(cpu));
+			writel(0, mvchip->membase + GPIO_LEVEL_MASK_MV78200_OFF(cpu));
+		}
+		break;
+	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
+		writel(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
+		writel(0, mvchip->membase + GPIO_EDGE_MASK_OFF);
+		writel(0, mvchip->membase + GPIO_LEVEL_MASK_OFF);
+		for (cpu = 0; cpu < 4; cpu++) {
+			writel(0, mvchip->percpu_membase + GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu));
+			writel(0, mvchip->percpu_membase + GPIO_EDGE_MASK_ARMADAXP_OFF(cpu));
+			writel(0, mvchip->percpu_membase + GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu));
+		}
+		break;
+	default:
+		BUG();
+	}
+
+	gpiochip_add(&mvchip->chip);
+
+	/* Setup the interrupt handlers. Each chip can have up to 4
+	 * interrupt handlers, with each handler dealing with 8 GPIO
+	 * pins. */
+	for (i = 0; i < 4; i++) {
+		int irq;
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0)
+			continue;
+		irq_set_handler_data(irq, mvchip);
+		irq_set_chained_handler(irq, mvebu_gpio_irq_handler);
+	}
+
+	irqbase = irq_alloc_descs(-1, 0, ngpios, -1);
+	if (irqbase < 0) {
+		dev_err(&pdev->dev, "no irqs\n");
+		kfree(mvchip->chip.label);
+		return -ENOMEM;
+	}
+
+	gc = irq_alloc_generic_chip("mvebu_gpio_irq", 2, mvchip->irqbase,
+				    mvchip->membase, handle_level_irq);
+	if (! gc) {
+		dev_err(&pdev->dev, "Cannot allocate generic irq_chip\n");
+		kfree(mvchip->chip.label);
+		return -ENOMEM;
+	}
+
+	gc->private = mvchip;
+	ct = &gc->chip_types[0];
+	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
+	ct->chip.irq_mask = mvebu_gpio_level_irq_mask;
+	ct->chip.irq_unmask = mvebu_gpio_level_irq_unmask;
+	ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
+	ct->chip.name = mvchip->chip.label;
+
+	ct = &gc->chip_types[1];
+	ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
+	ct->chip.irq_ack = mvebu_gpio_irq_ack;
+	ct->chip.irq_mask = mvebu_gpio_edge_irq_mask;
+	ct->chip.irq_unmask = mvebu_gpio_edge_irq_unmask;
+	ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
+	ct->handler = handle_edge_irq;
+	ct->chip.name = mvchip->chip.label;
+
+	irq_setup_generic_chip(gc, IRQ_MSK(ngpios), IRQ_GC_INIT_MASK_CACHE,
+			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
+
+	/* Setup irq domain on top of the generic chip. */
+	mvchip->domain = irq_domain_add_legacy(np, mvchip->chip.ngpio,
+					       mvchip->irqbase, 0,
+					       &irq_domain_simple_ops,
+					       mvchip);
+	if (!mvchip->domain) {
+		dev_err(&pdev->dev, "couldn't allocate irq domain %s (DT).\n",
+			mvchip->chip.label);
+		irq_remove_generic_chip(gc, IRQ_MSK(ngpios), IRQ_NOREQUEST,
+					IRQ_LEVEL | IRQ_NOPROBE);
+		kfree(gc);
+		kfree(mvchip->chip.label);
+		return -ENODEV;
+	}
+
+	mvebu_gpio_chip_count++;
+
+	return 0;
+}
+
+static struct platform_driver mvebu_gpio_driver = {
+	.driver		= {
+		.name	        = "mvebu-gpio",
+		.owner	        = THIS_MODULE,
+		.of_match_table = mvebu_gpio_of_match,
+	},
+	.probe		= mvebu_gpio_probe,
+	.id_table	= mvebu_gpio_ids,
+};
+
+static int __init mvebu_gpio_init(void)
+{
+	return platform_driver_register(&mvebu_gpio_driver);
+}
+postcore_initcall(mvebu_gpio_init);
-- 
1.7.9.5

[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

[Thomas Petazzoni]

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
---
 .../devicetree/bindings/gpio/gpio-mvebu.txt        |   44 ++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-mvebu.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
new file mode 100644
index 0000000..298436c
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
@@ -0,0 +1,44 @@
+* Marvell EBU GPIO controller
+
+Required properties:
+
+- compatible : Should be "marvell,orion-gpio", "marvell,mv78200-gpio"
+  or "marvell,armadaxp-gpio". "marvell,orion-gpio" should be used for
+  Orion, Kirkwood, Dove, Discovery (except MV78200) and Armada
+  370. "marvell,mv78200-gpio" should be used for the Discovery
+  MV78200. "marvel,armadaxp-gpio" should be used for all Armada XP
+  SoCs (MV78230, MV78260, MV78460).
+
+- reg: Address and length of the register set for the device. Only one
+  entry is expected, except for the "marvell,armadaxp-gpio" variant
+  for which two entries are expected: one for the general registers,
+  one for the per-cpu registers.
+
+- interrupts: The list of interrupts that are used for all the pins
+  managed by this GPIO bank. There can be more than one interrupt
+  (example: 1 interrupt per 8 pins on Armada XP, which means 4
+  interrupts per bank of 32 GPIOs).
+
+- interrupt-controller: identifies the node as an interrupt controller
+
+- #interrupt-cells: specifies the number of celles needed to encode an
+   interrupt source
+
+- gpio-controller: marks the device node as a gpio controller
+
+- ngpios: number of GPIOs this controller has
+
+- #gpio-cells: Should be one. It is the pin number.
+
+Example:
+
+		gpio0: gpio at d0018100 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018100 0x40>,
+			    <0xd0018800 0x30>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <16>, <17>, <18>, <19>;
+		};
-- 
1.7.9.5

[PATCH 3/5] arm: mvebu: use GPIO support now that a driver is available

[Thomas Petazzoni]

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
---
 arch/arm/Kconfig                        |    1 +
 arch/arm/mach-mvebu/include/mach/gpio.h |    1 +
 2 files changed, 2 insertions(+)
 create mode 100644 arch/arm/mach-mvebu/include/mach/gpio.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 95317a9..15b224c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -574,6 +574,7 @@ config ARCH_MVEBU
 	select IRQ_DOMAIN
 	select COMMON_CLK
 	select PINCTRL
+	select ARCH_WANT_OPTIONAL_GPIOLIB
 	help
 	  Support for the Marvell SoC Family with device tree support
 
diff --git a/arch/arm/mach-mvebu/include/mach/gpio.h b/arch/arm/mach-mvebu/include/mach/gpio.h
new file mode 100644
index 0000000..40a8c17
--- /dev/null
+++ b/arch/arm/mach-mvebu/include/mach/gpio.h
@@ -0,0 +1 @@
+/* empty */
-- 
1.7.9.5

[PATCH 4/5] arm: mvebu: add DT information for GPIO banks on Armada 370 and XP

[Thomas Petazzoni]

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
---
 arch/arm/boot/dts/armada-370.dtsi        |   30 +++++++++++++++++++++++++++
 arch/arm/boot/dts/armada-xp-mv78230.dtsi |   22 ++++++++++++++++++++
 arch/arm/boot/dts/armada-xp-mv78260.dtsi |   33 ++++++++++++++++++++++++++++++
 arch/arm/boot/dts/armada-xp-mv78460.dtsi |   33 ++++++++++++++++++++++++++++++
 4 files changed, 118 insertions(+)

diff --git a/arch/arm/boot/dts/armada-370.dtsi b/arch/arm/boot/dts/armada-370.dtsi
index 875fcd8..b0c832c 100644
--- a/arch/arm/boot/dts/armada-370.dtsi
+++ b/arch/arm/boot/dts/armada-370.dtsi
@@ -35,5 +35,35 @@
                 pinctrl at d0018000 {
 			        compatible = "marvell,mv88f6710-pinctrl";
 	        };
+
+		gpio0: gpio at d0018100 {
+			compatible = "marvell,orion-gpio";
+			reg = <0xd0018100 0x40>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <82>, <83>, <84>, <85>;
+		};
+
+		gpio1: gpio at d0018140 {
+			compatible = "marvell,orion-gpio";
+			reg = <0xd0018140 0x40>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <87>, <88>, <89>, <90>;
+		};
+
+		gpio2: gpio at d0018180 {
+			compatible = "marvell,orion-gpio";
+			reg = <0xd0018180 0x40>;
+			ngpios = <2>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <91>;
+		};
 	};
 };
diff --git a/arch/arm/boot/dts/armada-xp-mv78230.dtsi b/arch/arm/boot/dts/armada-xp-mv78230.dtsi
index 69ad287..081f3f7 100644
--- a/arch/arm/boot/dts/armada-xp-mv78230.dtsi
+++ b/arch/arm/boot/dts/armada-xp-mv78230.dtsi
@@ -23,5 +23,27 @@
 		pinctrl at d0018000 {
 			compatible = "marvell,mv78230-pinctrl";
 		};
+
+		gpio0: gpio at d0018100 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018100 0x40>,
+			    <0xd0018800 0x30>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <16>, <17>, <18>, <19>;
+		};
+
+		gpio1: gpio at d0018140 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018140 0x40>,
+			    <0xd0018840 0x30>;
+			ngpios = <17>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <20>, <21>, <22>;
+		};
 	};
 };
diff --git a/arch/arm/boot/dts/armada-xp-mv78260.dtsi b/arch/arm/boot/dts/armada-xp-mv78260.dtsi
index 0f38fa9..fa791fa 100644
--- a/arch/arm/boot/dts/armada-xp-mv78260.dtsi
+++ b/arch/arm/boot/dts/armada-xp-mv78260.dtsi
@@ -23,5 +23,38 @@
 		pinctrl at d0018000 {
 			compatible = "marvell,mv78260-pinctrl";
 		};
+
+		gpio0: gpio at d0018100 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018100 0x40>,
+			    <0xd0018800 0x30>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <16>, <17>, <18>, <19>;
+		};
+
+		gpio1: gpio at d0018140 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018140 0x40>,
+			    <0xd0018840 0x30>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <20>, <21>, <22>, <23>;
+		};
+
+		gpio2: gpio at d0018180 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018180 0x40>,
+			    <0xd0018870 0x30>;
+			ngpios = <3>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <24>;
+		};
 	};
 };
diff --git a/arch/arm/boot/dts/armada-xp-mv78460.dtsi b/arch/arm/boot/dts/armada-xp-mv78460.dtsi
index 9e61836..a372d13 100644
--- a/arch/arm/boot/dts/armada-xp-mv78460.dtsi
+++ b/arch/arm/boot/dts/armada-xp-mv78460.dtsi
@@ -23,5 +23,38 @@
 		pinctrl at d0018000 {
 			compatible = "marvell,mv78460-pinctrl";
 		};
+
+		gpio0: gpio at d0018100 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018100 0x40>,
+			    <0xd0018800 0x30>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <16>, <17>, <18>, <19>;
+		};
+
+		gpio1: gpio at d0018140 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018140 0x40>,
+			    <0xd0018840 0x30>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <20>, <21>, <22>, <23>;
+		};
+
+		gpio2: gpio at d0018180 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018180 0x40>,
+			    <0xd0018870 0x30>;
+			ngpios = <3>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <24>;
+		};
 	};
  };
-- 
1.7.9.5

[PATCH 5/5] arm: mvebu: add gpio support in defconfig

[Thomas Petazzoni]

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
---
 arch/arm/configs/mvebu_defconfig |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/mvebu_defconfig b/arch/arm/configs/mvebu_defconfig
index cb07e64..8dbb0bf 100644
--- a/arch/arm/configs/mvebu_defconfig
+++ b/arch/arm/configs/mvebu_defconfig
@@ -23,6 +23,8 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
 CONFIG_PINCTRL_ARMADA_370=y
 CONFIG_PINCTRL_ARMADA_XP=y
+CONFIG_GPIOLIB=y
+CONFIG_GPIO_SYSFS=y
 CONFIG_EXT2_FS=y
 CONFIG_EXT3_FS=y
 # CONFIG_EXT3_FS_XATTR is not set
-- 
1.7.9.5

[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

[Thomas Petazzoni]

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
---
 .../devicetree/bindings/gpio/gpio-mvebu.txt        |   44 ++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-mvebu.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
new file mode 100644
index 0000000..298436c
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-mvebu.txt
@@ -0,0 +1,44 @@
+* Marvell EBU GPIO controller
+
+Required properties:
+
+- compatible : Should be "marvell,orion-gpio", "marvell,mv78200-gpio"
+  or "marvell,armadaxp-gpio". "marvell,orion-gpio" should be used for
+  Orion, Kirkwood, Dove, Discovery (except MV78200) and Armada
+  370. "marvell,mv78200-gpio" should be used for the Discovery
+  MV78200. "marvel,armadaxp-gpio" should be used for all Armada XP
+  SoCs (MV78230, MV78260, MV78460).
+
+- reg: Address and length of the register set for the device. Only one
+  entry is expected, except for the "marvell,armadaxp-gpio" variant
+  for which two entries are expected: one for the general registers,
+  one for the per-cpu registers.
+
+- interrupts: The list of interrupts that are used for all the pins
+  managed by this GPIO bank. There can be more than one interrupt
+  (example: 1 interrupt per 8 pins on Armada XP, which means 4
+  interrupts per bank of 32 GPIOs).
+
+- interrupt-controller: identifies the node as an interrupt controller
+
+- #interrupt-cells: specifies the number of celles needed to encode an
+   interrupt source
+
+- gpio-controller: marks the device node as a gpio controller
+
+- ngpios: number of GPIOs this controller has
+
+- #gpio-cells: Should be one. It is the pin number.
+
+Example:
+
+		gpio0: gpio at d0018100 {
+			compatible = "marvell,armadaxp-gpio";
+			reg = <0xd0018100 0x40>,
+			    <0xd0018800 0x30>;
+			ngpios = <32>;
+			gpio-controller;
+			#gpio-cells = <1>;
+			interrupt-controller;
+			interrupts = <16>, <17>, <18>, <19>;
+		};
-- 
1.7.9.5

[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

[Linus Walleij]

On Sat, Aug 11, 2012 at 3:31 PM, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:

> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

FWIW:
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

[Olof Johansson]

Hi,

On Sat, Aug 11, 2012 at 03:31:43PM +0200, Thomas Petazzoni wrote:
> +- gpio-controller: marks the device node as a gpio controller
> +
> +- ngpios: number of GPIOs this controller has
> +
> +- #gpio-cells: Should be one. It is the pin number.

Most platforms will hit a need to encode polarity of the GPIO, in
particular on inputs. Having an extra cell for flags is quite useful.

[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

[Linus Walleij]

On Mon, Aug 27, 2012 at 11:53 PM, Olof Johansson <olof@lixom.net> wrote:
> Hi,
>
> On Sat, Aug 11, 2012 at 03:31:43PM +0200, Thomas Petazzoni wrote:
>> +- gpio-controller: marks the device node as a gpio controller
>> +
>> +- ngpios: number of GPIOs this controller has
>> +
>> +- #gpio-cells: Should be one. It is the pin number.
>
> Most platforms will hit a need to encode polarity of the GPIO, in
> particular on inputs. Having an extra cell for flags is quite useful.

Isn't that surplus in this case since this driver has a proper
pinctrl backend controlling such stuff? I don't really like
pinctrl portions of GPIOs being showeled into the GPIO
actually. Or am I just getting this wrong...?

Yours,
Linus Walleij

[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

[Olof Johansson]

On Sun, Sep 2, 2012 at 12:33 AM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Mon, Aug 27, 2012 at 11:53 PM, Olof Johansson <olof@lixom.net> wrote:
>> Hi,
>>
>> On Sat, Aug 11, 2012 at 03:31:43PM +0200, Thomas Petazzoni wrote:
>>> +- gpio-controller: marks the device node as a gpio controller
>>> +
>>> +- ngpios: number of GPIOs this controller has
>>> +
>>> +- #gpio-cells: Should be one. It is the pin number.
>>
>> Most platforms will hit a need to encode polarity of the GPIO, in
>> particular on inputs. Having an extra cell for flags is quite useful.
>
> Isn't that surplus in this case since this driver has a proper
> pinctrl backend controlling such stuff? I don't really like
> pinctrl portions of GPIOs being showeled into the GPIO
> actually. Or am I just getting this wrong...?

Ah, yes, true. Last time I had to add this was for a platform that
lacked pinctrl bindings (exynos).

I guess it doesn't hurt to add the flag since it might be used on
other OSes that have a gpio driver but not a pinctrl one, but that's a
pretty far corner case, no need to revise for it.


-Olof

[PATCH 2/5] Documentation: add description of DT binding for the gpio-mvebu driver

[Linus Walleij]

On Wed, Sep 5, 2012 at 6:51 AM, Olof Johansson <olof@lixom.net> wrote:

> I guess it doesn't hurt to add the flag since it might be used on
> other OSes that have a gpio driver but not a pinctrl one, but that's a
> pretty far corner case, no need to revise for it.

Sounds a bit ambigous and redundant, as we are in the driver
seat for device tree I'd prefer to force every other OS to get their
pinctrl concepts right ;-)

Linus Walleij