v4.19.13 snapshot.
diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
new file mode 100644
index 0000000..995cf0b
--- /dev/null
+++ b/drivers/gpio/gpio-mxc.c
@@ -0,0 +1,597 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
+// Copyright 2008 Juergen Beisert, kernel@pengutronix.de
+//
+// Based on code from Freescale Semiconductor,
+// Authors: Daniel Mack, Juergen Beisert.
+// Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/gpio/driver.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/bug.h>
+
+enum mxc_gpio_hwtype {
+	IMX1_GPIO,	/* runs on i.mx1 */
+	IMX21_GPIO,	/* runs on i.mx21 and i.mx27 */
+	IMX31_GPIO,	/* runs on i.mx31 */
+	IMX35_GPIO,	/* runs on all other i.mx */
+};
+
+/* device type dependent stuff */
+struct mxc_gpio_hwdata {
+	unsigned dr_reg;
+	unsigned gdir_reg;
+	unsigned psr_reg;
+	unsigned icr1_reg;
+	unsigned icr2_reg;
+	unsigned imr_reg;
+	unsigned isr_reg;
+	int edge_sel_reg;
+	unsigned low_level;
+	unsigned high_level;
+	unsigned rise_edge;
+	unsigned fall_edge;
+};
+
+struct mxc_gpio_reg_saved {
+	u32 icr1;
+	u32 icr2;
+	u32 imr;
+	u32 gdir;
+	u32 edge_sel;
+	u32 dr;
+};
+
+struct mxc_gpio_port {
+	struct list_head node;
+	void __iomem *base;
+	struct clk *clk;
+	int irq;
+	int irq_high;
+	struct irq_domain *domain;
+	struct gpio_chip gc;
+	struct device *dev;
+	u32 both_edges;
+	struct mxc_gpio_reg_saved gpio_saved_reg;
+	bool power_off;
+};
+
+static struct mxc_gpio_hwdata imx1_imx21_gpio_hwdata = {
+	.dr_reg		= 0x1c,
+	.gdir_reg	= 0x00,
+	.psr_reg	= 0x24,
+	.icr1_reg	= 0x28,
+	.icr2_reg	= 0x2c,
+	.imr_reg	= 0x30,
+	.isr_reg	= 0x34,
+	.edge_sel_reg	= -EINVAL,
+	.low_level	= 0x03,
+	.high_level	= 0x02,
+	.rise_edge	= 0x00,
+	.fall_edge	= 0x01,
+};
+
+static struct mxc_gpio_hwdata imx31_gpio_hwdata = {
+	.dr_reg		= 0x00,
+	.gdir_reg	= 0x04,
+	.psr_reg	= 0x08,
+	.icr1_reg	= 0x0c,
+	.icr2_reg	= 0x10,
+	.imr_reg	= 0x14,
+	.isr_reg	= 0x18,
+	.edge_sel_reg	= -EINVAL,
+	.low_level	= 0x00,
+	.high_level	= 0x01,
+	.rise_edge	= 0x02,
+	.fall_edge	= 0x03,
+};
+
+static struct mxc_gpio_hwdata imx35_gpio_hwdata = {
+	.dr_reg		= 0x00,
+	.gdir_reg	= 0x04,
+	.psr_reg	= 0x08,
+	.icr1_reg	= 0x0c,
+	.icr2_reg	= 0x10,
+	.imr_reg	= 0x14,
+	.isr_reg	= 0x18,
+	.edge_sel_reg	= 0x1c,
+	.low_level	= 0x00,
+	.high_level	= 0x01,
+	.rise_edge	= 0x02,
+	.fall_edge	= 0x03,
+};
+
+static enum mxc_gpio_hwtype mxc_gpio_hwtype;
+static struct mxc_gpio_hwdata *mxc_gpio_hwdata;
+
+#define GPIO_DR			(mxc_gpio_hwdata->dr_reg)
+#define GPIO_GDIR		(mxc_gpio_hwdata->gdir_reg)
+#define GPIO_PSR		(mxc_gpio_hwdata->psr_reg)
+#define GPIO_ICR1		(mxc_gpio_hwdata->icr1_reg)
+#define GPIO_ICR2		(mxc_gpio_hwdata->icr2_reg)
+#define GPIO_IMR		(mxc_gpio_hwdata->imr_reg)
+#define GPIO_ISR		(mxc_gpio_hwdata->isr_reg)
+#define GPIO_EDGE_SEL		(mxc_gpio_hwdata->edge_sel_reg)
+
+#define GPIO_INT_LOW_LEV	(mxc_gpio_hwdata->low_level)
+#define GPIO_INT_HIGH_LEV	(mxc_gpio_hwdata->high_level)
+#define GPIO_INT_RISE_EDGE	(mxc_gpio_hwdata->rise_edge)
+#define GPIO_INT_FALL_EDGE	(mxc_gpio_hwdata->fall_edge)
+#define GPIO_INT_BOTH_EDGES	0x4
+
+static const struct platform_device_id mxc_gpio_devtype[] = {
+	{
+		.name = "imx1-gpio",
+		.driver_data = IMX1_GPIO,
+	}, {
+		.name = "imx21-gpio",
+		.driver_data = IMX21_GPIO,
+	}, {
+		.name = "imx31-gpio",
+		.driver_data = IMX31_GPIO,
+	}, {
+		.name = "imx35-gpio",
+		.driver_data = IMX35_GPIO,
+	}, {
+		/* sentinel */
+	}
+};
+
+static const struct of_device_id mxc_gpio_dt_ids[] = {
+	{ .compatible = "fsl,imx1-gpio", .data = &mxc_gpio_devtype[IMX1_GPIO], },
+	{ .compatible = "fsl,imx21-gpio", .data = &mxc_gpio_devtype[IMX21_GPIO], },
+	{ .compatible = "fsl,imx31-gpio", .data = &mxc_gpio_devtype[IMX31_GPIO], },
+	{ .compatible = "fsl,imx35-gpio", .data = &mxc_gpio_devtype[IMX35_GPIO], },
+	{ .compatible = "fsl,imx7d-gpio", .data = &mxc_gpio_devtype[IMX35_GPIO], },
+	{ /* sentinel */ }
+};
+
+/*
+ * MX2 has one interrupt *for all* gpio ports. The list is used
+ * to save the references to all ports, so that mx2_gpio_irq_handler
+ * can walk through all interrupt status registers.
+ */
+static LIST_HEAD(mxc_gpio_ports);
+
+/* Note: This driver assumes 32 GPIOs are handled in one register */
+
+static int gpio_set_irq_type(struct irq_data *d, u32 type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct mxc_gpio_port *port = gc->private;
+	u32 bit, val;
+	u32 gpio_idx = d->hwirq;
+	int edge;
+	void __iomem *reg = port->base;
+
+	port->both_edges &= ~(1 << gpio_idx);
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		edge = GPIO_INT_RISE_EDGE;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		edge = GPIO_INT_FALL_EDGE;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		if (GPIO_EDGE_SEL >= 0) {
+			edge = GPIO_INT_BOTH_EDGES;
+		} else {
+			val = port->gc.get(&port->gc, gpio_idx);
+			if (val) {
+				edge = GPIO_INT_LOW_LEV;
+				pr_debug("mxc: set GPIO %d to low trigger\n", gpio_idx);
+			} else {
+				edge = GPIO_INT_HIGH_LEV;
+				pr_debug("mxc: set GPIO %d to high trigger\n", gpio_idx);
+			}
+			port->both_edges |= 1 << gpio_idx;
+		}
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		edge = GPIO_INT_LOW_LEV;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		edge = GPIO_INT_HIGH_LEV;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (GPIO_EDGE_SEL >= 0) {
+		val = readl(port->base + GPIO_EDGE_SEL);
+		if (edge == GPIO_INT_BOTH_EDGES)
+			writel(val | (1 << gpio_idx),
+				port->base + GPIO_EDGE_SEL);
+		else
+			writel(val & ~(1 << gpio_idx),
+				port->base + GPIO_EDGE_SEL);
+	}
+
+	if (edge != GPIO_INT_BOTH_EDGES) {
+		reg += GPIO_ICR1 + ((gpio_idx & 0x10) >> 2); /* lower or upper register */
+		bit = gpio_idx & 0xf;
+		val = readl(reg) & ~(0x3 << (bit << 1));
+		writel(val | (edge << (bit << 1)), reg);
+	}
+
+	writel(1 << gpio_idx, port->base + GPIO_ISR);
+
+	return 0;
+}
+
+static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
+{
+	void __iomem *reg = port->base;
+	u32 bit, val;
+	int edge;
+
+	reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */
+	bit = gpio & 0xf;
+	val = readl(reg);
+	edge = (val >> (bit << 1)) & 3;
+	val &= ~(0x3 << (bit << 1));
+	if (edge == GPIO_INT_HIGH_LEV) {
+		edge = GPIO_INT_LOW_LEV;
+		pr_debug("mxc: switch GPIO %d to low trigger\n", gpio);
+	} else if (edge == GPIO_INT_LOW_LEV) {
+		edge = GPIO_INT_HIGH_LEV;
+		pr_debug("mxc: switch GPIO %d to high trigger\n", gpio);
+	} else {
+		pr_err("mxc: invalid configuration for GPIO %d: %x\n",
+		       gpio, edge);
+		return;
+	}
+	writel(val | (edge << (bit << 1)), reg);
+}
+
+/* handle 32 interrupts in one status register */
+static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
+{
+	while (irq_stat != 0) {
+		int irqoffset = fls(irq_stat) - 1;
+
+		if (port->both_edges & (1 << irqoffset))
+			mxc_flip_edge(port, irqoffset);
+
+		generic_handle_irq(irq_find_mapping(port->domain, irqoffset));
+
+		irq_stat &= ~(1 << irqoffset);
+	}
+}
+
+/* MX1 and MX3 has one interrupt *per* gpio port */
+static void mx3_gpio_irq_handler(struct irq_desc *desc)
+{
+	u32 irq_stat;
+	struct mxc_gpio_port *port = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+
+	chained_irq_enter(chip, desc);
+
+	irq_stat = readl(port->base + GPIO_ISR) & readl(port->base + GPIO_IMR);
+
+	mxc_gpio_irq_handler(port, irq_stat);
+
+	chained_irq_exit(chip, desc);
+}
+
+/* MX2 has one interrupt *for all* gpio ports */
+static void mx2_gpio_irq_handler(struct irq_desc *desc)
+{
+	u32 irq_msk, irq_stat;
+	struct mxc_gpio_port *port;
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+
+	chained_irq_enter(chip, desc);
+
+	/* walk through all interrupt status registers */
+	list_for_each_entry(port, &mxc_gpio_ports, node) {
+		irq_msk = readl(port->base + GPIO_IMR);
+		if (!irq_msk)
+			continue;
+
+		irq_stat = readl(port->base + GPIO_ISR) & irq_msk;
+		if (irq_stat)
+			mxc_gpio_irq_handler(port, irq_stat);
+	}
+	chained_irq_exit(chip, desc);
+}
+
+/*
+ * Set interrupt number "irq" in the GPIO as a wake-up source.
+ * While system is running, all registered GPIO interrupts need to have
+ * wake-up enabled. When system is suspended, only selected GPIO interrupts
+ * need to have wake-up enabled.
+ * @param  irq          interrupt source number
+ * @param  enable       enable as wake-up if equal to non-zero
+ * @return       This function returns 0 on success.
+ */
+static int gpio_set_wake_irq(struct irq_data *d, u32 enable)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct mxc_gpio_port *port = gc->private;
+	u32 gpio_idx = d->hwirq;
+	int ret;
+
+	if (enable) {
+		if (port->irq_high && (gpio_idx >= 16))
+			ret = enable_irq_wake(port->irq_high);
+		else
+			ret = enable_irq_wake(port->irq);
+	} else {
+		if (port->irq_high && (gpio_idx >= 16))
+			ret = disable_irq_wake(port->irq_high);
+		else
+			ret = disable_irq_wake(port->irq);
+	}
+
+	return ret;
+}
+
+static int mxc_gpio_init_gc(struct mxc_gpio_port *port, int irq_base)
+{
+	struct irq_chip_generic *gc;
+	struct irq_chip_type *ct;
+	int rv;
+
+	gc = devm_irq_alloc_generic_chip(port->dev, "gpio-mxc", 1, irq_base,
+					 port->base, handle_level_irq);
+	if (!gc)
+		return -ENOMEM;
+	gc->private = port;
+
+	ct = gc->chip_types;
+	ct->chip.irq_ack = irq_gc_ack_set_bit;
+	ct->chip.irq_mask = irq_gc_mask_clr_bit;
+	ct->chip.irq_unmask = irq_gc_mask_set_bit;
+	ct->chip.irq_set_type = gpio_set_irq_type;
+	ct->chip.irq_set_wake = gpio_set_wake_irq;
+	ct->chip.flags = IRQCHIP_MASK_ON_SUSPEND;
+	ct->regs.ack = GPIO_ISR;
+	ct->regs.mask = GPIO_IMR;
+
+	rv = devm_irq_setup_generic_chip(port->dev, gc, IRQ_MSK(32),
+					 IRQ_GC_INIT_NESTED_LOCK,
+					 IRQ_NOREQUEST, 0);
+
+	return rv;
+}
+
+static void mxc_gpio_get_hw(struct platform_device *pdev)
+{
+	const struct of_device_id *of_id =
+			of_match_device(mxc_gpio_dt_ids, &pdev->dev);
+	enum mxc_gpio_hwtype hwtype;
+
+	if (of_id)
+		pdev->id_entry = of_id->data;
+	hwtype = pdev->id_entry->driver_data;
+
+	if (mxc_gpio_hwtype) {
+		/*
+		 * The driver works with a reasonable presupposition,
+		 * that is all gpio ports must be the same type when
+		 * running on one soc.
+		 */
+		BUG_ON(mxc_gpio_hwtype != hwtype);
+		return;
+	}
+
+	if (hwtype == IMX35_GPIO)
+		mxc_gpio_hwdata = &imx35_gpio_hwdata;
+	else if (hwtype == IMX31_GPIO)
+		mxc_gpio_hwdata = &imx31_gpio_hwdata;
+	else
+		mxc_gpio_hwdata = &imx1_imx21_gpio_hwdata;
+
+	mxc_gpio_hwtype = hwtype;
+}
+
+static int mxc_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+	struct mxc_gpio_port *port = gpiochip_get_data(gc);
+
+	return irq_find_mapping(port->domain, offset);
+}
+
+static int mxc_gpio_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mxc_gpio_port *port;
+	struct resource *iores;
+	int irq_base;
+	int err;
+
+	mxc_gpio_get_hw(pdev);
+
+	port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	port->dev = &pdev->dev;
+
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	port->base = devm_ioremap_resource(&pdev->dev, iores);
+	if (IS_ERR(port->base))
+		return PTR_ERR(port->base);
+
+	port->irq_high = platform_get_irq(pdev, 1);
+	if (port->irq_high < 0)
+		port->irq_high = 0;
+
+	port->irq = platform_get_irq(pdev, 0);
+	if (port->irq < 0)
+		return port->irq;
+
+	/* the controller clock is optional */
+	port->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(port->clk))
+		port->clk = NULL;
+
+	err = clk_prepare_enable(port->clk);
+	if (err) {
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+		return err;
+	}
+
+	if (of_device_is_compatible(np, "fsl,imx7d-gpio"))
+		port->power_off = true;
+
+	/* disable the interrupt and clear the status */
+	writel(0, port->base + GPIO_IMR);
+	writel(~0, port->base + GPIO_ISR);
+
+	if (mxc_gpio_hwtype == IMX21_GPIO) {
+		/*
+		 * Setup one handler for all GPIO interrupts. Actually setting
+		 * the handler is needed only once, but doing it for every port
+		 * is more robust and easier.
+		 */
+		irq_set_chained_handler(port->irq, mx2_gpio_irq_handler);
+	} else {
+		/* setup one handler for each entry */
+		irq_set_chained_handler_and_data(port->irq,
+						 mx3_gpio_irq_handler, port);
+		if (port->irq_high > 0)
+			/* setup handler for GPIO 16 to 31 */
+			irq_set_chained_handler_and_data(port->irq_high,
+							 mx3_gpio_irq_handler,
+							 port);
+	}
+
+	err = bgpio_init(&port->gc, &pdev->dev, 4,
+			 port->base + GPIO_PSR,
+			 port->base + GPIO_DR, NULL,
+			 port->base + GPIO_GDIR, NULL,
+			 BGPIOF_READ_OUTPUT_REG_SET);
+	if (err)
+		goto out_bgio;
+
+	if (of_property_read_bool(np, "gpio-ranges")) {
+		port->gc.request = gpiochip_generic_request;
+		port->gc.free = gpiochip_generic_free;
+	}
+
+	port->gc.to_irq = mxc_gpio_to_irq;
+	port->gc.base = (pdev->id < 0) ? of_alias_get_id(np, "gpio") * 32 :
+					     pdev->id * 32;
+
+	err = devm_gpiochip_add_data(&pdev->dev, &port->gc, port);
+	if (err)
+		goto out_bgio;
+
+	irq_base = devm_irq_alloc_descs(&pdev->dev, -1, 0, 32, numa_node_id());
+	if (irq_base < 0) {
+		err = irq_base;
+		goto out_bgio;
+	}
+
+	port->domain = irq_domain_add_legacy(np, 32, irq_base, 0,
+					     &irq_domain_simple_ops, NULL);
+	if (!port->domain) {
+		err = -ENODEV;
+		goto out_bgio;
+	}
+
+	/* gpio-mxc can be a generic irq chip */
+	err = mxc_gpio_init_gc(port, irq_base);
+	if (err < 0)
+		goto out_irqdomain_remove;
+
+	list_add_tail(&port->node, &mxc_gpio_ports);
+
+	platform_set_drvdata(pdev, port);
+
+	return 0;
+
+out_irqdomain_remove:
+	irq_domain_remove(port->domain);
+out_bgio:
+	clk_disable_unprepare(port->clk);
+	dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, err);
+	return err;
+}
+
+static void mxc_gpio_save_regs(struct mxc_gpio_port *port)
+{
+	if (!port->power_off)
+		return;
+
+	port->gpio_saved_reg.icr1 = readl(port->base + GPIO_ICR1);
+	port->gpio_saved_reg.icr2 = readl(port->base + GPIO_ICR2);
+	port->gpio_saved_reg.imr = readl(port->base + GPIO_IMR);
+	port->gpio_saved_reg.gdir = readl(port->base + GPIO_GDIR);
+	port->gpio_saved_reg.edge_sel = readl(port->base + GPIO_EDGE_SEL);
+	port->gpio_saved_reg.dr = readl(port->base + GPIO_DR);
+}
+
+static void mxc_gpio_restore_regs(struct mxc_gpio_port *port)
+{
+	if (!port->power_off)
+		return;
+
+	writel(port->gpio_saved_reg.icr1, port->base + GPIO_ICR1);
+	writel(port->gpio_saved_reg.icr2, port->base + GPIO_ICR2);
+	writel(port->gpio_saved_reg.imr, port->base + GPIO_IMR);
+	writel(port->gpio_saved_reg.gdir, port->base + GPIO_GDIR);
+	writel(port->gpio_saved_reg.edge_sel, port->base + GPIO_EDGE_SEL);
+	writel(port->gpio_saved_reg.dr, port->base + GPIO_DR);
+}
+
+static int __maybe_unused mxc_gpio_noirq_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct mxc_gpio_port *port = platform_get_drvdata(pdev);
+
+	mxc_gpio_save_regs(port);
+	clk_disable_unprepare(port->clk);
+
+	return 0;
+}
+
+static int __maybe_unused mxc_gpio_noirq_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct mxc_gpio_port *port = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = clk_prepare_enable(port->clk);
+	if (ret)
+		return ret;
+	mxc_gpio_restore_regs(port);
+
+	return 0;
+}
+
+static const struct dev_pm_ops mxc_gpio_dev_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mxc_gpio_noirq_suspend, mxc_gpio_noirq_resume)
+};
+
+static struct platform_driver mxc_gpio_driver = {
+	.driver		= {
+		.name	= "gpio-mxc",
+		.of_match_table = mxc_gpio_dt_ids,
+		.suppress_bind_attrs = true,
+		.pm = &mxc_gpio_dev_pm_ops,
+	},
+	.probe		= mxc_gpio_probe,
+	.id_table	= mxc_gpio_devtype,
+};
+
+static int __init gpio_mxc_init(void)
+{
+	return platform_driver_register(&mxc_gpio_driver);
+}
+subsys_initcall(gpio_mxc_init);