1 files changed, 767 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c
new file mode 100644
index 0000000000..bccdbfd5ec
--- /dev/null
+++ b/drivers/gpio/gpio-brcmstb.c
@@ -0,0 +1,767 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2015-2017 Broadcom
+
+#include <linux/bitops.h>
+#include <linux/gpio/driver.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+enum gio_reg_index {
+	GIO_REG_ODEN = 0,
+	GIO_REG_DATA,
+	GIO_REG_IODIR,
+	GIO_REG_EC,
+	GIO_REG_EI,
+	GIO_REG_MASK,
+	GIO_REG_LEVEL,
+	GIO_REG_STAT,
+	NUMBER_OF_GIO_REGISTERS
+};
+
+#define GIO_BANK_SIZE           (NUMBER_OF_GIO_REGISTERS * sizeof(u32))
+#define GIO_BANK_OFF(bank, off)	(((bank) * GIO_BANK_SIZE) + (off * sizeof(u32)))
+#define GIO_ODEN(bank)          GIO_BANK_OFF(bank, GIO_REG_ODEN)
+#define GIO_DATA(bank)          GIO_BANK_OFF(bank, GIO_REG_DATA)
+#define GIO_IODIR(bank)         GIO_BANK_OFF(bank, GIO_REG_IODIR)
+#define GIO_EC(bank)            GIO_BANK_OFF(bank, GIO_REG_EC)
+#define GIO_EI(bank)            GIO_BANK_OFF(bank, GIO_REG_EI)
+#define GIO_MASK(bank)          GIO_BANK_OFF(bank, GIO_REG_MASK)
+#define GIO_LEVEL(bank)         GIO_BANK_OFF(bank, GIO_REG_LEVEL)
+#define GIO_STAT(bank)          GIO_BANK_OFF(bank, GIO_REG_STAT)
+
+struct brcmstb_gpio_bank {
+	struct list_head node;
+	int id;
+	struct gpio_chip gc;
+	struct brcmstb_gpio_priv *parent_priv;
+	u32 width;
+	u32 wake_active;
+	u32 saved_regs[GIO_REG_STAT]; /* Don't save and restore GIO_REG_STAT */
+};
+
+struct brcmstb_gpio_priv {
+	struct list_head bank_list;
+	void __iomem *reg_base;
+	struct platform_device *pdev;
+	struct irq_domain *irq_domain;
+	struct irq_chip irq_chip;
+	int parent_irq;
+	int gpio_base;
+	int num_gpios;
+	int parent_wake_irq;
+};
+
+#define MAX_GPIO_PER_BANK       32
+#define GPIO_BANK(gpio)         ((gpio) >> 5)
+/* assumes MAX_GPIO_PER_BANK is a multiple of 2 */
+#define GPIO_BIT(gpio)          ((gpio) & (MAX_GPIO_PER_BANK - 1))
+
+static inline struct brcmstb_gpio_priv *
+brcmstb_gpio_gc_to_priv(struct gpio_chip *gc)
+{
+	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+	return bank->parent_priv;
+}
+
+static unsigned long
+__brcmstb_gpio_get_active_irqs(struct brcmstb_gpio_bank *bank)
+{
+	void __iomem *reg_base = bank->parent_priv->reg_base;
+
+	return bank->gc.read_reg(reg_base + GIO_STAT(bank->id)) &
+	       bank->gc.read_reg(reg_base + GIO_MASK(bank->id));
+}
+
+static unsigned long
+brcmstb_gpio_get_active_irqs(struct brcmstb_gpio_bank *bank)
+{
+	unsigned long status;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&bank->gc.bgpio_lock, flags);
+	status = __brcmstb_gpio_get_active_irqs(bank);
+	raw_spin_unlock_irqrestore(&bank->gc.bgpio_lock, flags);
+
+	return status;
+}
+
+static int brcmstb_gpio_hwirq_to_offset(irq_hw_number_t hwirq,
+					struct brcmstb_gpio_bank *bank)
+{
+	return hwirq - (bank->gc.base - bank->parent_priv->gpio_base);
+}
+
+static void brcmstb_gpio_set_imask(struct brcmstb_gpio_bank *bank,
+		unsigned int hwirq, bool enable)
+{
+	struct gpio_chip *gc = &bank->gc;
+	struct brcmstb_gpio_priv *priv = bank->parent_priv;
+	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(hwirq, bank));
+	u32 imask;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
+	imask = gc->read_reg(priv->reg_base + GIO_MASK(bank->id));
+	if (enable)
+		imask |= mask;
+	else
+		imask &= ~mask;
+	gc->write_reg(priv->reg_base + GIO_MASK(bank->id), imask);
+	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+}
+
+static int brcmstb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+	struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
+	/* gc_offset is relative to this gpio_chip; want real offset */
+	int hwirq = offset + (gc->base - priv->gpio_base);
+
+	if (hwirq >= priv->num_gpios)
+		return -ENXIO;
+	return irq_create_mapping(priv->irq_domain, hwirq);
+}
+
+/* -------------------- IRQ chip functions -------------------- */
+
+static void brcmstb_gpio_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+
+	brcmstb_gpio_set_imask(bank, d->hwirq, false);
+}
+
+static void brcmstb_gpio_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+
+	brcmstb_gpio_set_imask(bank, d->hwirq, true);
+}
+
+static void brcmstb_gpio_irq_ack(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+	struct brcmstb_gpio_priv *priv = bank->parent_priv;
+	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
+
+	gc->write_reg(priv->reg_base + GIO_STAT(bank->id), mask);
+}
+
+static int brcmstb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+	struct brcmstb_gpio_priv *priv = bank->parent_priv;
+	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
+	u32 edge_insensitive, iedge_insensitive;
+	u32 edge_config, iedge_config;
+	u32 level, ilevel;
+	unsigned long flags;
+
+	switch (type) {
+	case IRQ_TYPE_LEVEL_LOW:
+		level = mask;
+		edge_config = 0;
+		edge_insensitive = 0;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		level = mask;
+		edge_config = mask;
+		edge_insensitive = 0;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		level = 0;
+		edge_config = 0;
+		edge_insensitive = 0;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		level = 0;
+		edge_config = mask;
+		edge_insensitive = 0;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		level = 0;
+		edge_config = 0;  /* don't care, but want known value */
+		edge_insensitive = mask;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	raw_spin_lock_irqsave(&bank->gc.bgpio_lock, flags);
+
+	iedge_config = bank->gc.read_reg(priv->reg_base +
+			GIO_EC(bank->id)) & ~mask;
+	iedge_insensitive = bank->gc.read_reg(priv->reg_base +
+			GIO_EI(bank->id)) & ~mask;
+	ilevel = bank->gc.read_reg(priv->reg_base +
+			GIO_LEVEL(bank->id)) & ~mask;
+
+	bank->gc.write_reg(priv->reg_base + GIO_EC(bank->id),
+			iedge_config | edge_config);
+	bank->gc.write_reg(priv->reg_base + GIO_EI(bank->id),
+			iedge_insensitive | edge_insensitive);
+	bank->gc.write_reg(priv->reg_base + GIO_LEVEL(bank->id),
+			ilevel | level);
+
+	raw_spin_unlock_irqrestore(&bank->gc.bgpio_lock, flags);
+	return 0;
+}
+
+static int brcmstb_gpio_priv_set_wake(struct brcmstb_gpio_priv *priv,
+		unsigned int enable)
+{
+	int ret = 0;
+
+	if (enable)
+		ret = enable_irq_wake(priv->parent_wake_irq);
+	else
+		ret = disable_irq_wake(priv->parent_wake_irq);
+	if (ret)
+		dev_err(&priv->pdev->dev, "failed to %s wake-up interrupt\n",
+				enable ? "enable" : "disable");
+	return ret;
+}
+
+static int brcmstb_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+	struct brcmstb_gpio_priv *priv = bank->parent_priv;
+	u32 mask = BIT(brcmstb_gpio_hwirq_to_offset(d->hwirq, bank));
+
+	/*
+	 * Do not do anything specific for now, suspend/resume callbacks will
+	 * configure the interrupt mask appropriately
+	 */
+	if (enable)
+		bank->wake_active |= mask;
+	else
+		bank->wake_active &= ~mask;
+
+	return brcmstb_gpio_priv_set_wake(priv, enable);
+}
+
+static irqreturn_t brcmstb_gpio_wake_irq_handler(int irq, void *data)
+{
+	struct brcmstb_gpio_priv *priv = data;
+
+	if (!priv || irq != priv->parent_wake_irq)
+		return IRQ_NONE;
+
+	/* Nothing to do */
+	return IRQ_HANDLED;
+}
+
+static void brcmstb_gpio_irq_bank_handler(struct brcmstb_gpio_bank *bank)
+{
+	struct brcmstb_gpio_priv *priv = bank->parent_priv;
+	struct irq_domain *domain = priv->irq_domain;
+	int hwbase = bank->gc.base - priv->gpio_base;
+	unsigned long status;
+
+	while ((status = brcmstb_gpio_get_active_irqs(bank))) {
+		unsigned int offset;
+
+		for_each_set_bit(offset, &status, 32) {
+			if (offset >= bank->width)
+				dev_warn(&priv->pdev->dev,
+					 "IRQ for invalid GPIO (bank=%d, offset=%d)\n",
+					 bank->id, offset);
+			generic_handle_domain_irq(domain, hwbase + offset);
+		}
+	}
+}
+
+/* Each UPG GIO block has one IRQ for all banks */
+static void brcmstb_gpio_irq_handler(struct irq_desc *desc)
+{
+	struct brcmstb_gpio_priv *priv = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct brcmstb_gpio_bank *bank;
+
+	/* Interrupts weren't properly cleared during probe */
+	BUG_ON(!priv || !chip);
+
+	chained_irq_enter(chip, desc);
+	list_for_each_entry(bank, &priv->bank_list, node)
+		brcmstb_gpio_irq_bank_handler(bank);
+	chained_irq_exit(chip, desc);
+}
+
+static struct brcmstb_gpio_bank *brcmstb_gpio_hwirq_to_bank(
+		struct brcmstb_gpio_priv *priv, irq_hw_number_t hwirq)
+{
+	struct brcmstb_gpio_bank *bank;
+	int i = 0;
+
+	/* banks are in descending order */
+	list_for_each_entry_reverse(bank, &priv->bank_list, node) {
+		i += bank->gc.ngpio;
+		if (hwirq < i)
+			return bank;
+	}
+	return NULL;
+}
+
+/*
+ * This lock class tells lockdep that GPIO irqs are in a different
+ * category than their parents, so it won't report false recursion.
+ */
+static struct lock_class_key brcmstb_gpio_irq_lock_class;
+static struct lock_class_key brcmstb_gpio_irq_request_class;
+
+
+static int brcmstb_gpio_irq_map(struct irq_domain *d, unsigned int irq,
+		irq_hw_number_t hwirq)
+{
+	struct brcmstb_gpio_priv *priv = d->host_data;
+	struct brcmstb_gpio_bank *bank =
+		brcmstb_gpio_hwirq_to_bank(priv, hwirq);
+	struct platform_device *pdev = priv->pdev;
+	int ret;
+
+	if (!bank)
+		return -EINVAL;
+
+	dev_dbg(&pdev->dev, "Mapping irq %d for gpio line %d (bank %d)\n",
+		irq, (int)hwirq, bank->id);
+	ret = irq_set_chip_data(irq, &bank->gc);
+	if (ret < 0)
+		return ret;
+	irq_set_lockdep_class(irq, &brcmstb_gpio_irq_lock_class,
+			      &brcmstb_gpio_irq_request_class);
+	irq_set_chip_and_handler(irq, &priv->irq_chip, handle_level_irq);
+	irq_set_noprobe(irq);
+	return 0;
+}
+
+static void brcmstb_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+}
+
+static const struct irq_domain_ops brcmstb_gpio_irq_domain_ops = {
+	.map = brcmstb_gpio_irq_map,
+	.unmap = brcmstb_gpio_irq_unmap,
+	.xlate = irq_domain_xlate_twocell,
+};
+
+/* Make sure that the number of banks matches up between properties */
+static int brcmstb_gpio_sanity_check_banks(struct device *dev,
+		struct device_node *np, struct resource *res)
+{
+	int res_num_banks = resource_size(res) / GIO_BANK_SIZE;
+	int num_banks =
+		of_property_count_u32_elems(np, "brcm,gpio-bank-widths");
+
+	if (res_num_banks != num_banks) {
+		dev_err(dev, "Mismatch in banks: res had %d, bank-widths had %d\n",
+				res_num_banks, num_banks);
+		return -EINVAL;
+	} else {
+		return 0;
+	}
+}
+
+static int brcmstb_gpio_remove(struct platform_device *pdev)
+{
+	struct brcmstb_gpio_priv *priv = platform_get_drvdata(pdev);
+	struct brcmstb_gpio_bank *bank;
+	int offset, virq;
+
+	if (priv->parent_irq > 0)
+		irq_set_chained_handler_and_data(priv->parent_irq, NULL, NULL);
+
+	/* Remove all IRQ mappings and delete the domain */
+	if (priv->irq_domain) {
+		for (offset = 0; offset < priv->num_gpios; offset++) {
+			virq = irq_find_mapping(priv->irq_domain, offset);
+			irq_dispose_mapping(virq);
+		}
+		irq_domain_remove(priv->irq_domain);
+	}
+
+	/*
+	 * You can lose return values below, but we report all errors, and it's
+	 * more important to actually perform all of the steps.
+	 */
+	list_for_each_entry(bank, &priv->bank_list, node)
+		gpiochip_remove(&bank->gc);
+
+	return 0;
+}
+
+static int brcmstb_gpio_of_xlate(struct gpio_chip *gc,
+		const struct of_phandle_args *gpiospec, u32 *flags)
+{
+	struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
+	struct brcmstb_gpio_bank *bank = gpiochip_get_data(gc);
+	int offset;
+
+	if (gc->of_gpio_n_cells != 2) {
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
+		return -EINVAL;
+
+	offset = gpiospec->args[0] - (gc->base - priv->gpio_base);
+	if (offset >= gc->ngpio || offset < 0)
+		return -EINVAL;
+
+	if (unlikely(offset >= bank->width)) {
+		dev_warn_ratelimited(&priv->pdev->dev,
+			"Received request for invalid GPIO offset %d\n",
+			gpiospec->args[0]);
+	}
+
+	if (flags)
+		*flags = gpiospec->args[1];
+
+	return offset;
+}
+
+/* priv->parent_irq and priv->num_gpios must be set before calling */
+static int brcmstb_gpio_irq_setup(struct platform_device *pdev,
+		struct brcmstb_gpio_priv *priv)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	int err;
+
+	priv->irq_domain =
+		irq_domain_add_linear(np, priv->num_gpios,
+				      &brcmstb_gpio_irq_domain_ops,
+				      priv);
+	if (!priv->irq_domain) {
+		dev_err(dev, "Couldn't allocate IRQ domain\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_bool(np, "wakeup-source")) {
+		priv->parent_wake_irq = platform_get_irq(pdev, 1);
+		if (priv->parent_wake_irq < 0) {
+			priv->parent_wake_irq = 0;
+			dev_warn(dev,
+				"Couldn't get wake IRQ - GPIOs will not be able to wake from sleep");
+		} else {
+			/*
+			 * Set wakeup capability so we can process boot-time
+			 * "wakeups" (e.g., from S5 cold boot)
+			 */
+			device_set_wakeup_capable(dev, true);
+			device_wakeup_enable(dev);
+			err = devm_request_irq(dev, priv->parent_wake_irq,
+					       brcmstb_gpio_wake_irq_handler,
+					       IRQF_SHARED,
+					       "brcmstb-gpio-wake", priv);
+
+			if (err < 0) {
+				dev_err(dev, "Couldn't request wake IRQ");
+				goto out_free_domain;
+			}
+		}
+	}
+
+	priv->irq_chip.name = dev_name(dev);
+	priv->irq_chip.irq_disable = brcmstb_gpio_irq_mask;
+	priv->irq_chip.irq_mask = brcmstb_gpio_irq_mask;
+	priv->irq_chip.irq_unmask = brcmstb_gpio_irq_unmask;
+	priv->irq_chip.irq_ack = brcmstb_gpio_irq_ack;
+	priv->irq_chip.irq_set_type = brcmstb_gpio_irq_set_type;
+
+	if (priv->parent_wake_irq)
+		priv->irq_chip.irq_set_wake = brcmstb_gpio_irq_set_wake;
+
+	irq_set_chained_handler_and_data(priv->parent_irq,
+					 brcmstb_gpio_irq_handler, priv);
+	irq_set_status_flags(priv->parent_irq, IRQ_DISABLE_UNLAZY);
+
+	return 0;
+
+out_free_domain:
+	irq_domain_remove(priv->irq_domain);
+
+	return err;
+}
+
+static void brcmstb_gpio_bank_save(struct brcmstb_gpio_priv *priv,
+				   struct brcmstb_gpio_bank *bank)
+{
+	struct gpio_chip *gc = &bank->gc;
+	unsigned int i;
+
+	for (i = 0; i < GIO_REG_STAT; i++)
+		bank->saved_regs[i] = gc->read_reg(priv->reg_base +
+						   GIO_BANK_OFF(bank->id, i));
+}
+
+static void brcmstb_gpio_quiesce(struct device *dev, bool save)
+{
+	struct brcmstb_gpio_priv *priv = dev_get_drvdata(dev);
+	struct brcmstb_gpio_bank *bank;
+	struct gpio_chip *gc;
+	u32 imask;
+
+	/* disable non-wake interrupt */
+	if (priv->parent_irq >= 0)
+		disable_irq(priv->parent_irq);
+
+	list_for_each_entry(bank, &priv->bank_list, node) {
+		gc = &bank->gc;
+
+		if (save)
+			brcmstb_gpio_bank_save(priv, bank);
+
+		/* Unmask GPIOs which have been flagged as wake-up sources */
+		if (priv->parent_wake_irq)
+			imask = bank->wake_active;
+		else
+			imask = 0;
+		gc->write_reg(priv->reg_base + GIO_MASK(bank->id),
+			       imask);
+	}
+}
+
+static void brcmstb_gpio_shutdown(struct platform_device *pdev)
+{
+	/* Enable GPIO for S5 cold boot */
+	brcmstb_gpio_quiesce(&pdev->dev, false);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static void brcmstb_gpio_bank_restore(struct brcmstb_gpio_priv *priv,
+				      struct brcmstb_gpio_bank *bank)
+{
+	struct gpio_chip *gc = &bank->gc;
+	unsigned int i;
+
+	for (i = 0; i < GIO_REG_STAT; i++)
+		gc->write_reg(priv->reg_base + GIO_BANK_OFF(bank->id, i),
+			      bank->saved_regs[i]);
+}
+
+static int brcmstb_gpio_suspend(struct device *dev)
+{
+	brcmstb_gpio_quiesce(dev, true);
+	return 0;
+}
+
+static int brcmstb_gpio_resume(struct device *dev)
+{
+	struct brcmstb_gpio_priv *priv = dev_get_drvdata(dev);
+	struct brcmstb_gpio_bank *bank;
+	bool need_wakeup_event = false;
+
+	list_for_each_entry(bank, &priv->bank_list, node) {
+		need_wakeup_event |= !!__brcmstb_gpio_get_active_irqs(bank);
+		brcmstb_gpio_bank_restore(priv, bank);
+	}
+
+	if (priv->parent_wake_irq && need_wakeup_event)
+		pm_wakeup_event(dev, 0);
+
+	/* enable non-wake interrupt */
+	if (priv->parent_irq >= 0)
+		enable_irq(priv->parent_irq);
+
+	return 0;
+}
+
+#else
+#define brcmstb_gpio_suspend	NULL
+#define brcmstb_gpio_resume	NULL
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops brcmstb_gpio_pm_ops = {
+	.suspend_noirq	= brcmstb_gpio_suspend,
+	.resume_noirq = brcmstb_gpio_resume,
+};
+
+static int brcmstb_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	void __iomem *reg_base;
+	struct brcmstb_gpio_priv *priv;
+	struct resource *res;
+	struct property *prop;
+	const __be32 *p;
+	u32 bank_width;
+	int num_banks = 0;
+	int err;
+	static int gpio_base;
+	unsigned long flags = 0;
+	bool need_wakeup_event = false;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, priv);
+	INIT_LIST_HEAD(&priv->bank_list);
+
+	reg_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(reg_base))
+		return PTR_ERR(reg_base);
+
+	priv->gpio_base = gpio_base;
+	priv->reg_base = reg_base;
+	priv->pdev = pdev;
+
+	if (of_property_read_bool(np, "interrupt-controller")) {
+		priv->parent_irq = platform_get_irq(pdev, 0);
+		if (priv->parent_irq <= 0)
+			return -ENOENT;
+	} else {
+		priv->parent_irq = -ENOENT;
+	}
+
+	if (brcmstb_gpio_sanity_check_banks(dev, np, res))
+		return -EINVAL;
+
+	/*
+	 * MIPS endianness is configured by boot strap, which also reverses all
+	 * bus endianness (i.e., big-endian CPU + big endian bus ==> native
+	 * endian I/O).
+	 *
+	 * Other architectures (e.g., ARM) either do not support big endian, or
+	 * else leave I/O in little endian mode.
+	 */
+#if defined(CONFIG_MIPS) && defined(__BIG_ENDIAN)
+	flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER;
+#endif
+
+	of_property_for_each_u32(np, "brcm,gpio-bank-widths", prop, p,
+			bank_width) {
+		struct brcmstb_gpio_bank *bank;
+		struct gpio_chip *gc;
+
+		/*
+		 * If bank_width is 0, then there is an empty bank in the
+		 * register block. Special handling for this case.
+		 */
+		if (bank_width == 0) {
+			dev_dbg(dev, "Width 0 found: Empty bank @ %d\n",
+				num_banks);
+			num_banks++;
+			gpio_base += MAX_GPIO_PER_BANK;
+			continue;
+		}
+
+		bank = devm_kzalloc(dev, sizeof(*bank), GFP_KERNEL);
+		if (!bank) {
+			err = -ENOMEM;
+			goto fail;
+		}
+
+		bank->parent_priv = priv;
+		bank->id = num_banks;
+		if (bank_width <= 0 || bank_width > MAX_GPIO_PER_BANK) {
+			dev_err(dev, "Invalid bank width %d\n", bank_width);
+			err = -EINVAL;
+			goto fail;
+		} else {
+			bank->width = bank_width;
+		}
+
+		/*
+		 * Regs are 4 bytes wide, have data reg, no set/clear regs,
+		 * and direction bits have 0 = output and 1 = input
+		 */
+		gc = &bank->gc;
+		err = bgpio_init(gc, dev, 4,
+				reg_base + GIO_DATA(bank->id),
+				NULL, NULL, NULL,
+				reg_base + GIO_IODIR(bank->id), flags);
+		if (err) {
+			dev_err(dev, "bgpio_init() failed\n");
+			goto fail;
+		}
+
+		gc->owner = THIS_MODULE;
+		gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pOF", np);
+		if (!gc->label) {
+			err = -ENOMEM;
+			goto fail;
+		}
+		gc->base = gpio_base;
+		gc->of_gpio_n_cells = 2;
+		gc->of_xlate = brcmstb_gpio_of_xlate;
+		/* not all ngpio lines are valid, will use bank width later */
+		gc->ngpio = MAX_GPIO_PER_BANK;
+		gc->offset = bank->id * MAX_GPIO_PER_BANK;
+		if (priv->parent_irq > 0)
+			gc->to_irq = brcmstb_gpio_to_irq;
+
+		/*
+		 * Mask all interrupts by default, since wakeup interrupts may
+		 * be retained from S5 cold boot
+		 */
+		need_wakeup_event |= !!__brcmstb_gpio_get_active_irqs(bank);
+		gc->write_reg(reg_base + GIO_MASK(bank->id), 0);
+
+		err = gpiochip_add_data(gc, bank);
+		if (err) {
+			dev_err(dev, "Could not add gpiochip for bank %d\n",
+					bank->id);
+			goto fail;
+		}
+		gpio_base += gc->ngpio;
+
+		dev_dbg(dev, "bank=%d, base=%d, ngpio=%d, width=%d\n", bank->id,
+			gc->base, gc->ngpio, bank->width);
+
+		/* Everything looks good, so add bank to list */
+		list_add(&bank->node, &priv->bank_list);
+
+		num_banks++;
+	}
+
+	priv->num_gpios = gpio_base - priv->gpio_base;
+	if (priv->parent_irq > 0) {
+		err = brcmstb_gpio_irq_setup(pdev, priv);
+		if (err)
+			goto fail;
+	}
+
+	if (priv->parent_wake_irq && need_wakeup_event)
+		pm_wakeup_event(dev, 0);
+
+	return 0;
+
+fail:
+	(void) brcmstb_gpio_remove(pdev);
+	return err;
+}
+
+static const struct of_device_id brcmstb_gpio_of_match[] = {
+	{ .compatible = "brcm,brcmstb-gpio" },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, brcmstb_gpio_of_match);
+
+static struct platform_driver brcmstb_gpio_driver = {
+	.driver = {
+		.name = "brcmstb-gpio",
+		.of_match_table = brcmstb_gpio_of_match,
+		.pm = &brcmstb_gpio_pm_ops,
+	},
+	.probe = brcmstb_gpio_probe,
+	.remove = brcmstb_gpio_remove,
+	.shutdown = brcmstb_gpio_shutdown,
+};
+module_platform_driver(brcmstb_gpio_driver);
+
+MODULE_AUTHOR("Gregory Fong");
+MODULE_DESCRIPTION("Driver for Broadcom BRCMSTB SoC UPG GPIO");
+MODULE_LICENSE("GPL v2");