Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 729 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c
new file mode 100644
index 000000000..69f3d864f
--- /dev/null
+++ b/drivers/gpio/gpio-davinci.c
@@ -0,0 +1,729 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TI DaVinci GPIO Support
+ *
+ * Copyright (c) 2006-2007 David Brownell
+ * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/gpio-davinci.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/spinlock.h>
+#include <linux/pm_runtime.h>
+
+#include <asm-generic/gpio.h>
+
+#define MAX_REGS_BANKS 5
+#define MAX_INT_PER_BANK 32
+
+struct davinci_gpio_regs {
+	u32	dir;
+	u32	out_data;
+	u32	set_data;
+	u32	clr_data;
+	u32	in_data;
+	u32	set_rising;
+	u32	clr_rising;
+	u32	set_falling;
+	u32	clr_falling;
+	u32	intstat;
+};
+
+typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq);
+
+#define BINTEN	0x8 /* GPIO Interrupt Per-Bank Enable Register */
+
+static void __iomem *gpio_base;
+static unsigned int offset_array[5] = {0x10, 0x38, 0x60, 0x88, 0xb0};
+
+struct davinci_gpio_irq_data {
+	void __iomem			*regs;
+	struct davinci_gpio_controller	*chip;
+	int				bank_num;
+};
+
+struct davinci_gpio_controller {
+	struct gpio_chip	chip;
+	struct irq_domain	*irq_domain;
+	/* Serialize access to GPIO registers */
+	spinlock_t		lock;
+	void __iomem		*regs[MAX_REGS_BANKS];
+	int			gpio_unbanked;
+	int			irqs[MAX_INT_PER_BANK];
+	struct davinci_gpio_regs context[MAX_REGS_BANKS];
+	u32			binten_context;
+};
+
+static inline u32 __gpio_mask(unsigned gpio)
+{
+	return 1 << (gpio % 32);
+}
+
+static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d)
+{
+	struct davinci_gpio_regs __iomem *g;
+
+	g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d);
+
+	return g;
+}
+
+static int davinci_gpio_irq_setup(struct platform_device *pdev);
+
+/*--------------------------------------------------------------------------*/
+
+/* board setup code *MUST* setup pinmux and enable the GPIO clock. */
+static inline int __davinci_direction(struct gpio_chip *chip,
+			unsigned offset, bool out, int value)
+{
+	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
+	struct davinci_gpio_regs __iomem *g;
+	unsigned long flags;
+	u32 temp;
+	int bank = offset / 32;
+	u32 mask = __gpio_mask(offset);
+
+	g = d->regs[bank];
+	spin_lock_irqsave(&d->lock, flags);
+	temp = readl_relaxed(&g->dir);
+	if (out) {
+		temp &= ~mask;
+		writel_relaxed(mask, value ? &g->set_data : &g->clr_data);
+	} else {
+		temp |= mask;
+	}
+	writel_relaxed(temp, &g->dir);
+	spin_unlock_irqrestore(&d->lock, flags);
+
+	return 0;
+}
+
+static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+	return __davinci_direction(chip, offset, false, 0);
+}
+
+static int
+davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
+{
+	return __davinci_direction(chip, offset, true, value);
+}
+
+/*
+ * Read the pin's value (works even if it's set up as output);
+ * returns zero/nonzero.
+ *
+ * Note that changes are synched to the GPIO clock, so reading values back
+ * right after you've set them may give old values.
+ */
+static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
+	struct davinci_gpio_regs __iomem *g;
+	int bank = offset / 32;
+
+	g = d->regs[bank];
+
+	return !!(__gpio_mask(offset) & readl_relaxed(&g->in_data));
+}
+
+/*
+ * Assuming the pin is muxed as a gpio output, set its output value.
+ */
+static void
+davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
+	struct davinci_gpio_regs __iomem *g;
+	int bank = offset / 32;
+
+	g = d->regs[bank];
+
+	writel_relaxed(__gpio_mask(offset),
+		       value ? &g->set_data : &g->clr_data);
+}
+
+static struct davinci_gpio_platform_data *
+davinci_gpio_get_pdata(struct platform_device *pdev)
+{
+	struct device_node *dn = pdev->dev.of_node;
+	struct davinci_gpio_platform_data *pdata;
+	int ret;
+	u32 val;
+
+	if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
+		return dev_get_platdata(&pdev->dev);
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return NULL;
+
+	ret = of_property_read_u32(dn, "ti,ngpio", &val);
+	if (ret)
+		goto of_err;
+
+	pdata->ngpio = val;
+
+	ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val);
+	if (ret)
+		goto of_err;
+
+	pdata->gpio_unbanked = val;
+
+	return pdata;
+
+of_err:
+	dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret);
+	return NULL;
+}
+
+static int davinci_gpio_probe(struct platform_device *pdev)
+{
+	int bank, i, ret = 0;
+	unsigned int ngpio, nbank, nirq;
+	struct davinci_gpio_controller *chips;
+	struct davinci_gpio_platform_data *pdata;
+	struct device *dev = &pdev->dev;
+
+	pdata = davinci_gpio_get_pdata(pdev);
+	if (!pdata) {
+		dev_err(dev, "No platform data found\n");
+		return -EINVAL;
+	}
+
+	dev->platform_data = pdata;
+
+	/*
+	 * The gpio banks conceptually expose a segmented bitmap,
+	 * and "ngpio" is one more than the largest zero-based
+	 * bit index that's valid.
+	 */
+	ngpio = pdata->ngpio;
+	if (ngpio == 0) {
+		dev_err(dev, "How many GPIOs?\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON(ARCH_NR_GPIOS < ngpio))
+		ngpio = ARCH_NR_GPIOS;
+
+	/*
+	 * If there are unbanked interrupts then the number of
+	 * interrupts is equal to number of gpios else all are banked so
+	 * number of interrupts is equal to number of banks(each with 16 gpios)
+	 */
+	if (pdata->gpio_unbanked)
+		nirq = pdata->gpio_unbanked;
+	else
+		nirq = DIV_ROUND_UP(ngpio, 16);
+
+	chips = devm_kzalloc(dev, sizeof(*chips), GFP_KERNEL);
+	if (!chips)
+		return -ENOMEM;
+
+	gpio_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(gpio_base))
+		return PTR_ERR(gpio_base);
+
+	for (i = 0; i < nirq; i++) {
+		chips->irqs[i] = platform_get_irq(pdev, i);
+		if (chips->irqs[i] < 0)
+			return dev_err_probe(dev, chips->irqs[i], "IRQ not populated\n");
+	}
+
+	chips->chip.label = dev_name(dev);
+
+	chips->chip.direction_input = davinci_direction_in;
+	chips->chip.get = davinci_gpio_get;
+	chips->chip.direction_output = davinci_direction_out;
+	chips->chip.set = davinci_gpio_set;
+
+	chips->chip.ngpio = ngpio;
+	chips->chip.base = pdata->no_auto_base ? pdata->base : -1;
+
+#ifdef CONFIG_OF_GPIO
+	chips->chip.of_gpio_n_cells = 2;
+	chips->chip.parent = dev;
+	chips->chip.request = gpiochip_generic_request;
+	chips->chip.free = gpiochip_generic_free;
+#endif
+	spin_lock_init(&chips->lock);
+
+	nbank = DIV_ROUND_UP(ngpio, 32);
+	for (bank = 0; bank < nbank; bank++)
+		chips->regs[bank] = gpio_base + offset_array[bank];
+
+	ret = devm_gpiochip_add_data(dev, &chips->chip, chips);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, chips);
+	ret = davinci_gpio_irq_setup(pdev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*--------------------------------------------------------------------------*/
+/*
+ * We expect irqs will normally be set up as input pins, but they can also be
+ * used as output pins ... which is convenient for testing.
+ *
+ * NOTE:  The first few GPIOs also have direct INTC hookups in addition
+ * to their GPIOBNK0 irq, with a bit less overhead.
+ *
+ * All those INTC hookups (direct, plus several IRQ banks) can also
+ * serve as EDMA event triggers.
+ */
+
+static void gpio_irq_disable(struct irq_data *d)
+{
+	struct davinci_gpio_regs __iomem *g = irq2regs(d);
+	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
+
+	writel_relaxed(mask, &g->clr_falling);
+	writel_relaxed(mask, &g->clr_rising);
+}
+
+static void gpio_irq_enable(struct irq_data *d)
+{
+	struct davinci_gpio_regs __iomem *g = irq2regs(d);
+	uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d);
+	unsigned status = irqd_get_trigger_type(d);
+
+	status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
+	if (!status)
+		status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
+
+	if (status & IRQ_TYPE_EDGE_FALLING)
+		writel_relaxed(mask, &g->set_falling);
+	if (status & IRQ_TYPE_EDGE_RISING)
+		writel_relaxed(mask, &g->set_rising);
+}
+
+static int gpio_irq_type(struct irq_data *d, unsigned trigger)
+{
+	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+		return -EINVAL;
+
+	return 0;
+}
+
+static struct irq_chip gpio_irqchip = {
+	.name		= "GPIO",
+	.irq_enable	= gpio_irq_enable,
+	.irq_disable	= gpio_irq_disable,
+	.irq_set_type	= gpio_irq_type,
+	.flags		= IRQCHIP_SET_TYPE_MASKED | IRQCHIP_SKIP_SET_WAKE,
+};
+
+static void gpio_irq_handler(struct irq_desc *desc)
+{
+	struct davinci_gpio_regs __iomem *g;
+	u32 mask = 0xffff;
+	int bank_num;
+	struct davinci_gpio_controller *d;
+	struct davinci_gpio_irq_data *irqdata;
+
+	irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc);
+	bank_num = irqdata->bank_num;
+	g = irqdata->regs;
+	d = irqdata->chip;
+
+	/* we only care about one bank */
+	if ((bank_num % 2) == 1)
+		mask <<= 16;
+
+	/* temporarily mask (level sensitive) parent IRQ */
+	chained_irq_enter(irq_desc_get_chip(desc), desc);
+	while (1) {
+		u32		status;
+		int		bit;
+		irq_hw_number_t hw_irq;
+
+		/* ack any irqs */
+		status = readl_relaxed(&g->intstat) & mask;
+		if (!status)
+			break;
+		writel_relaxed(status, &g->intstat);
+
+		/* now demux them to the right lowlevel handler */
+
+		while (status) {
+			bit = __ffs(status);
+			status &= ~BIT(bit);
+			/* Max number of gpios per controller is 144 so
+			 * hw_irq will be in [0..143]
+			 */
+			hw_irq = (bank_num / 2) * 32 + bit;
+
+			generic_handle_domain_irq(d->irq_domain, hw_irq);
+		}
+	}
+	chained_irq_exit(irq_desc_get_chip(desc), desc);
+	/* now it may re-trigger */
+}
+
+static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
+
+	if (d->irq_domain)
+		return irq_create_mapping(d->irq_domain, offset);
+	else
+		return -ENXIO;
+}
+
+static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *d = gpiochip_get_data(chip);
+
+	/*
+	 * NOTE:  we assume for now that only irqs in the first gpio_chip
+	 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
+	 */
+	if (offset < d->gpio_unbanked)
+		return d->irqs[offset];
+	else
+		return -ENODEV;
+}
+
+static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
+{
+	struct davinci_gpio_controller *d;
+	struct davinci_gpio_regs __iomem *g;
+	u32 mask, i;
+
+	d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data);
+	g = (struct davinci_gpio_regs __iomem *)d->regs[0];
+	for (i = 0; i < MAX_INT_PER_BANK; i++)
+		if (data->irq == d->irqs[i])
+			break;
+
+	if (i == MAX_INT_PER_BANK)
+		return -EINVAL;
+
+	mask = __gpio_mask(i);
+
+	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
+		return -EINVAL;
+
+	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
+		     ? &g->set_falling : &g->clr_falling);
+	writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING)
+		     ? &g->set_rising : &g->clr_rising);
+
+	return 0;
+}
+
+static int
+davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
+		     irq_hw_number_t hw)
+{
+	struct davinci_gpio_controller *chips =
+				(struct davinci_gpio_controller *)d->host_data;
+	struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32];
+
+	irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
+				"davinci_gpio");
+	irq_set_irq_type(irq, IRQ_TYPE_NONE);
+	irq_set_chip_data(irq, (__force void *)g);
+	irq_set_handler_data(irq, (void *)(uintptr_t)__gpio_mask(hw));
+
+	return 0;
+}
+
+static const struct irq_domain_ops davinci_gpio_irq_ops = {
+	.map = davinci_gpio_irq_map,
+	.xlate = irq_domain_xlate_onetwocell,
+};
+
+static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq)
+{
+	static struct irq_chip_type gpio_unbanked;
+
+	gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq));
+
+	return &gpio_unbanked.chip;
+};
+
+static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq)
+{
+	static struct irq_chip gpio_unbanked;
+
+	gpio_unbanked = *irq_get_chip(irq);
+	return &gpio_unbanked;
+};
+
+static const struct of_device_id davinci_gpio_ids[];
+
+/*
+ * NOTE:  for suspend/resume, probably best to make a platform_device with
+ * suspend_late/resume_resume calls hooking into results of the set_wake()
+ * calls ... so if no gpios are wakeup events the clock can be disabled,
+ * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
+ * (dm6446) can be set appropriately for GPIOV33 pins.
+ */
+
+static int davinci_gpio_irq_setup(struct platform_device *pdev)
+{
+	unsigned	gpio, bank;
+	int		irq;
+	int		ret;
+	struct clk	*clk;
+	u32		binten = 0;
+	unsigned	ngpio;
+	struct device *dev = &pdev->dev;
+	struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
+	struct davinci_gpio_platform_data *pdata = dev->platform_data;
+	struct davinci_gpio_regs __iomem *g;
+	struct irq_domain	*irq_domain = NULL;
+	const struct of_device_id *match;
+	struct irq_chip *irq_chip;
+	struct davinci_gpio_irq_data *irqdata;
+	gpio_get_irq_chip_cb_t gpio_get_irq_chip;
+
+	/*
+	 * Use davinci_gpio_get_irq_chip by default to handle non DT cases
+	 */
+	gpio_get_irq_chip = davinci_gpio_get_irq_chip;
+	match = of_match_device(of_match_ptr(davinci_gpio_ids),
+				dev);
+	if (match)
+		gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data;
+
+	ngpio = pdata->ngpio;
+
+	clk = devm_clk_get(dev, "gpio");
+	if (IS_ERR(clk)) {
+		dev_err(dev, "Error %ld getting gpio clock\n", PTR_ERR(clk));
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
+
+	if (!pdata->gpio_unbanked) {
+		irq = devm_irq_alloc_descs(dev, -1, 0, ngpio, 0);
+		if (irq < 0) {
+			dev_err(dev, "Couldn't allocate IRQ numbers\n");
+			clk_disable_unprepare(clk);
+			return irq;
+		}
+
+		irq_domain = irq_domain_add_legacy(dev->of_node, ngpio, irq, 0,
+							&davinci_gpio_irq_ops,
+							chips);
+		if (!irq_domain) {
+			dev_err(dev, "Couldn't register an IRQ domain\n");
+			clk_disable_unprepare(clk);
+			return -ENODEV;
+		}
+	}
+
+	/*
+	 * Arrange gpio_to_irq() support, handling either direct IRQs or
+	 * banked IRQs.  Having GPIOs in the first GPIO bank use direct
+	 * IRQs, while the others use banked IRQs, would need some setup
+	 * tweaks to recognize hardware which can do that.
+	 */
+	chips->chip.to_irq = gpio_to_irq_banked;
+	chips->irq_domain = irq_domain;
+
+	/*
+	 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
+	 * controller only handling trigger modes.  We currently assume no
+	 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
+	 */
+	if (pdata->gpio_unbanked) {
+		/* pass "bank 0" GPIO IRQs to AINTC */
+		chips->chip.to_irq = gpio_to_irq_unbanked;
+		chips->gpio_unbanked = pdata->gpio_unbanked;
+		binten = GENMASK(pdata->gpio_unbanked / 16, 0);
+
+		/* AINTC handles mask/unmask; GPIO handles triggering */
+		irq = chips->irqs[0];
+		irq_chip = gpio_get_irq_chip(irq);
+		irq_chip->name = "GPIO-AINTC";
+		irq_chip->irq_set_type = gpio_irq_type_unbanked;
+
+		/* default trigger: both edges */
+		g = chips->regs[0];
+		writel_relaxed(~0, &g->set_falling);
+		writel_relaxed(~0, &g->set_rising);
+
+		/* set the direct IRQs up to use that irqchip */
+		for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++) {
+			irq_set_chip(chips->irqs[gpio], irq_chip);
+			irq_set_handler_data(chips->irqs[gpio], chips);
+			irq_set_status_flags(chips->irqs[gpio],
+					     IRQ_TYPE_EDGE_BOTH);
+		}
+
+		goto done;
+	}
+
+	/*
+	 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
+	 * then chain through our own handler.
+	 */
+	for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 16) {
+		/* disabled by default, enabled only as needed
+		 * There are register sets for 32 GPIOs. 2 banks of 16
+		 * GPIOs are covered by each set of registers hence divide by 2
+		 */
+		g = chips->regs[bank / 2];
+		writel_relaxed(~0, &g->clr_falling);
+		writel_relaxed(~0, &g->clr_rising);
+
+		/*
+		 * Each chip handles 32 gpios, and each irq bank consists of 16
+		 * gpio irqs. Pass the irq bank's corresponding controller to
+		 * the chained irq handler.
+		 */
+		irqdata = devm_kzalloc(&pdev->dev,
+				       sizeof(struct
+					      davinci_gpio_irq_data),
+					      GFP_KERNEL);
+		if (!irqdata) {
+			clk_disable_unprepare(clk);
+			return -ENOMEM;
+		}
+
+		irqdata->regs = g;
+		irqdata->bank_num = bank;
+		irqdata->chip = chips;
+
+		irq_set_chained_handler_and_data(chips->irqs[bank],
+						 gpio_irq_handler, irqdata);
+
+		binten |= BIT(bank);
+	}
+
+done:
+	/*
+	 * BINTEN -- per-bank interrupt enable. genirq would also let these
+	 * bits be set/cleared dynamically.
+	 */
+	writel_relaxed(binten, gpio_base + BINTEN);
+
+	return 0;
+}
+
+static void davinci_gpio_save_context(struct davinci_gpio_controller *chips,
+				      u32 nbank)
+{
+	struct davinci_gpio_regs __iomem *g;
+	struct davinci_gpio_regs *context;
+	u32 bank;
+	void __iomem *base;
+
+	base = chips->regs[0] - offset_array[0];
+	chips->binten_context = readl_relaxed(base + BINTEN);
+
+	for (bank = 0; bank < nbank; bank++) {
+		g = chips->regs[bank];
+		context = &chips->context[bank];
+		context->dir = readl_relaxed(&g->dir);
+		context->set_data = readl_relaxed(&g->set_data);
+		context->set_rising = readl_relaxed(&g->set_rising);
+		context->set_falling = readl_relaxed(&g->set_falling);
+	}
+
+	/* Clear all interrupt status registers */
+	writel_relaxed(GENMASK(31, 0), &g->intstat);
+}
+
+static void davinci_gpio_restore_context(struct davinci_gpio_controller *chips,
+					 u32 nbank)
+{
+	struct davinci_gpio_regs __iomem *g;
+	struct davinci_gpio_regs *context;
+	u32 bank;
+	void __iomem *base;
+
+	base = chips->regs[0] - offset_array[0];
+
+	if (readl_relaxed(base + BINTEN) != chips->binten_context)
+		writel_relaxed(chips->binten_context, base + BINTEN);
+
+	for (bank = 0; bank < nbank; bank++) {
+		g = chips->regs[bank];
+		context = &chips->context[bank];
+		if (readl_relaxed(&g->dir) != context->dir)
+			writel_relaxed(context->dir, &g->dir);
+		if (readl_relaxed(&g->set_data) != context->set_data)
+			writel_relaxed(context->set_data, &g->set_data);
+		if (readl_relaxed(&g->set_rising) != context->set_rising)
+			writel_relaxed(context->set_rising, &g->set_rising);
+		if (readl_relaxed(&g->set_falling) != context->set_falling)
+			writel_relaxed(context->set_falling, &g->set_falling);
+	}
+}
+
+static int davinci_gpio_suspend(struct device *dev)
+{
+	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
+	struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
+	u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
+
+	davinci_gpio_save_context(chips, nbank);
+
+	return 0;
+}
+
+static int davinci_gpio_resume(struct device *dev)
+{
+	struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
+	struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
+	u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
+
+	davinci_gpio_restore_context(chips, nbank);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_DEV_PM_OPS(davinci_gpio_dev_pm_ops, davinci_gpio_suspend,
+			 davinci_gpio_resume);
+
+static const struct of_device_id davinci_gpio_ids[] = {
+	{ .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
+	{ .compatible = "ti,am654-gpio", keystone_gpio_get_irq_chip},
+	{ .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, davinci_gpio_ids);
+
+static struct platform_driver davinci_gpio_driver = {
+	.probe		= davinci_gpio_probe,
+	.driver		= {
+		.name		= "davinci_gpio",
+		.pm = pm_sleep_ptr(&davinci_gpio_dev_pm_ops),
+		.of_match_table	= of_match_ptr(davinci_gpio_ids),
+	},
+};
+
+/**
+ * GPIO driver registration needs to be done before machine_init functions
+ * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall.
+ */
+static int __init davinci_gpio_drv_reg(void)
+{
+	return platform_driver_register(&davinci_gpio_driver);
+}
+postcore_initcall(davinci_gpio_drv_reg);