drivers/gpio/gpio-ath79.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Atheros AR71XX/AR724X/AR913X GPIO API support
  *
  *  Copyright (C) 2015 Alban Bedel <albeu@free.fr>
  *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
  *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
  *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
  */

 #include <linux/gpio/driver.h>
 #include <linux/platform_data/gpio-ath79.h>
 #include <linux/of_device.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/irq.h>

 #define AR71XX_GPIO_REG_OE		0x00
 #define AR71XX_GPIO_REG_IN		0x04
 #define AR71XX_GPIO_REG_SET		0x0c
 #define AR71XX_GPIO_REG_CLEAR		0x10

 #define AR71XX_GPIO_REG_INT_ENABLE	0x14
 #define AR71XX_GPIO_REG_INT_TYPE	0x18
 #define AR71XX_GPIO_REG_INT_POLARITY	0x1c
 #define AR71XX_GPIO_REG_INT_PENDING	0x20
 #define AR71XX_GPIO_REG_INT_MASK	0x24

 struct ath79_gpio_ctrl {
 	struct gpio_chip gc;
 	void __iomem *base;
 	raw_spinlock_t lock;
 	unsigned long both_edges;
 };

 static struct ath79_gpio_ctrl *irq_data_to_ath79_gpio(struct irq_data *data)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);

 	return container_of(gc, struct ath79_gpio_ctrl, gc);
 }

 static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg)
 {
 	return readl(ctrl->base + reg);
 }

 static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl,
 			unsigned reg, u32 val)
 {
 	writel(val, ctrl->base + reg);
 }

 static bool ath79_gpio_update_bits(
 	struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits)
 {
 	u32 old_val, new_val;

 	old_val = ath79_gpio_read(ctrl, reg);
 	new_val = (old_val & ~mask) | (bits & mask);

 	if (new_val != old_val)
 		ath79_gpio_write(ctrl, reg, new_val);

 	return new_val != old_val;
 }

 static void ath79_gpio_irq_unmask(struct irq_data *data)
 {
 	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;

 	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
 	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }

 static void ath79_gpio_irq_mask(struct irq_data *data)
 {
 	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;

 	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
 	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }

 static void ath79_gpio_irq_enable(struct irq_data *data)
 {
 	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;

 	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
 	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }

 static void ath79_gpio_irq_disable(struct irq_data *data)
 {
 	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 	u32 mask = BIT(irqd_to_hwirq(data));
 	unsigned long flags;

 	raw_spin_lock_irqsave(&ctrl->lock, flags);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
 	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
 	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 }

 static int ath79_gpio_irq_set_type(struct irq_data *data,
 				unsigned int flow_type)
 {
 	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 	u32 mask = BIT(irqd_to_hwirq(data));
 	u32 type = 0, polarity = 0;
 	unsigned long flags;
 	bool disabled;

 	switch (flow_type) {
 	case IRQ_TYPE_EDGE_RISING:
 		polarity |= mask;
 		fallthrough;
 	case IRQ_TYPE_EDGE_FALLING:
 	case IRQ_TYPE_EDGE_BOTH:
 		break;

 	case IRQ_TYPE_LEVEL_HIGH:
 		polarity |= mask;
 		fallthrough;
 	case IRQ_TYPE_LEVEL_LOW:
 		type |= mask;
 		break;

 	default:
 		return -EINVAL;
 	}

 	raw_spin_lock_irqsave(&ctrl->lock, flags);

 	if (flow_type == IRQ_TYPE_EDGE_BOTH) {
 		ctrl->both_edges |= mask;
 		polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
 	} else {
 		ctrl->both_edges &= ~mask;
 	}

 	/* As the IRQ configuration can't be loaded atomically we
 	 * have to disable the interrupt while the configuration state
 	 * is invalid.
 	 */
 	disabled = ath79_gpio_update_bits(
 		ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);

 	ath79_gpio_update_bits(
 		ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type);
 	ath79_gpio_update_bits(
 		ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity);

 	if (disabled)
 		ath79_gpio_update_bits(
 			ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);

 	raw_spin_unlock_irqrestore(&ctrl->lock, flags);

 	return 0;
 }

 static struct irq_chip ath79_gpio_irqchip = {
 	.name = "gpio-ath79",
 	.irq_enable = ath79_gpio_irq_enable,
 	.irq_disable = ath79_gpio_irq_disable,
 	.irq_mask = ath79_gpio_irq_mask,
 	.irq_unmask = ath79_gpio_irq_unmask,
 	.irq_set_type = ath79_gpio_irq_set_type,
 };

 static void ath79_gpio_irq_handler(struct irq_desc *desc)
 {
 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 	struct irq_chip *irqchip = irq_desc_get_chip(desc);
 	struct ath79_gpio_ctrl *ctrl =
 		container_of(gc, struct ath79_gpio_ctrl, gc);
 	unsigned long flags, pending;
 	u32 both_edges, state;
 	int irq;

 	chained_irq_enter(irqchip, desc);

 	raw_spin_lock_irqsave(&ctrl->lock, flags);

 	pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING);

 	/* Update the polarity of the both edges irqs */
 	both_edges = ctrl->both_edges & pending;
 	if (both_edges) {
 		state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
 		ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY,
 				both_edges, ~state);
 	}

 	raw_spin_unlock_irqrestore(&ctrl->lock, flags);

 	if (pending) {
 		for_each_set_bit(irq, &pending, gc->ngpio)
 			generic_handle_irq(
 				irq_linear_revmap(gc->irq.domain, irq));
 	}

 	chained_irq_exit(irqchip, desc);
 }

 static const struct of_device_id ath79_gpio_of_match[] = {
 	{ .compatible = "qca,ar7100-gpio" },
 	{ .compatible = "qca,ar9340-gpio" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ath79_gpio_of_match);

 static int ath79_gpio_probe(struct platform_device *pdev)
 {
 	struct ath79_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct ath79_gpio_ctrl *ctrl;
 	struct gpio_irq_chip *girq;
 	u32 ath79_gpio_count;
 	bool oe_inverted;
 	int err;

 	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
 	if (!ctrl)
 		return -ENOMEM;

 	if (np) {
 		err = of_property_read_u32(np, "ngpios", &ath79_gpio_count);
 		if (err) {
 			dev_err(dev, "ngpios property is not valid\n");
 			return err;
 		}
 		oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio");
 	} else if (pdata) {
 		ath79_gpio_count = pdata->ngpios;
 		oe_inverted = pdata->oe_inverted;
 	} else {
 		dev_err(dev, "No DT node or platform data found\n");
 		return -EINVAL;
 	}

 	if (ath79_gpio_count >= 32) {
 		dev_err(dev, "ngpios must be less than 32\n");
 		return -EINVAL;
 	}

 	ctrl->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(ctrl->base))
 		return PTR_ERR(ctrl->base);

 	raw_spin_lock_init(&ctrl->lock);
 	err = bgpio_init(&ctrl->gc, dev, 4,
 			ctrl->base + AR71XX_GPIO_REG_IN,
 			ctrl->base + AR71XX_GPIO_REG_SET,
 			ctrl->base + AR71XX_GPIO_REG_CLEAR,
 			oe_inverted ? NULL : ctrl->base + AR71XX_GPIO_REG_OE,
 			oe_inverted ? ctrl->base + AR71XX_GPIO_REG_OE : NULL,
 			0);
 	if (err) {
 		dev_err(dev, "bgpio_init failed\n");
 		return err;
 	}
 	/* Use base 0 to stay compatible with legacy platforms */
 	ctrl->gc.base = 0;

 	/* Optional interrupt setup */
 	if (!np || of_property_read_bool(np, "interrupt-controller")) {
 		girq = &ctrl->gc.irq;
 		girq->chip = &ath79_gpio_irqchip;
 		girq->parent_handler = ath79_gpio_irq_handler;
 		girq->num_parents = 1;
 		girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
 					     GFP_KERNEL);
 		if (!girq->parents)
 			return -ENOMEM;
 		girq->parents[0] = platform_get_irq(pdev, 0);
 		girq->default_type = IRQ_TYPE_NONE;
 		girq->handler = handle_simple_irq;
 	}

 	return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
 }

 static struct platform_driver ath79_gpio_driver = {
 	.driver = {
 		.name = "ath79-gpio",
 		.of_match_table	= ath79_gpio_of_match,
 	},
 	.probe = ath79_gpio_probe,
 };

 module_platform_driver(ath79_gpio_driver);

 MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X GPIO API support");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Atheros AR71XX/AR724X/AR913X GPIO API support
	*
	* Copyright (C) 2015 Alban Bedel <albeu@free.fr>
	* Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
	* Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
	* Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
	*/

	#include <linux/gpio/driver.h>
	#include <linux/platform_data/gpio-ath79.h>
	#include <linux/of_device.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/irq.h>

	#define AR71XX_GPIO_REG_OE 0x00
	#define AR71XX_GPIO_REG_IN 0x04
	#define AR71XX_GPIO_REG_SET 0x0c
	#define AR71XX_GPIO_REG_CLEAR 0x10

	#define AR71XX_GPIO_REG_INT_ENABLE 0x14
	#define AR71XX_GPIO_REG_INT_TYPE 0x18
	#define AR71XX_GPIO_REG_INT_POLARITY 0x1c
	#define AR71XX_GPIO_REG_INT_PENDING 0x20
	#define AR71XX_GPIO_REG_INT_MASK 0x24

	struct ath79_gpio_ctrl {
	struct gpio_chip gc;
	void __iomem *base;
	raw_spinlock_t lock;
	unsigned long both_edges;
	};

	static struct ath79_gpio_ctrl irq_data_to_ath79_gpio(struct irq_data data)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(data);

	return container_of(gc, struct ath79_gpio_ctrl, gc);
	}

	static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg)
	{
	return readl(ctrl->base + reg);
	}

	static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl,
	unsigned reg, u32 val)
	{
	writel(val, ctrl->base + reg);
	}

	static bool ath79_gpio_update_bits(
	struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits)
	{
	u32 old_val, new_val;

	old_val = ath79_gpio_read(ctrl, reg);
	new_val = (old_val & ~mask) \| (bits & mask);

	if (new_val != old_val)
	ath79_gpio_write(ctrl, reg, new_val);

	return new_val != old_val;
	}

	static void ath79_gpio_irq_unmask(struct irq_data *data)
	{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	raw_spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
	}

	static void ath79_gpio_irq_mask(struct irq_data *data)
	{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	raw_spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
	}

	static void ath79_gpio_irq_enable(struct irq_data *data)
	{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	raw_spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
	}

	static void ath79_gpio_irq_disable(struct irq_data *data)
	{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	unsigned long flags;

	raw_spin_lock_irqsave(&ctrl->lock, flags);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
	raw_spin_unlock_irqrestore(&ctrl->lock, flags);
	}

	static int ath79_gpio_irq_set_type(struct irq_data *data,
	unsigned int flow_type)
	{
	struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
	u32 mask = BIT(irqd_to_hwirq(data));
	u32 type = 0, polarity = 0;
	unsigned long flags;
	bool disabled;

	switch (flow_type) {
	case IRQ_TYPE_EDGE_RISING:
	polarity \|= mask;
	fallthrough;
	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_EDGE_BOTH:
	break;

	case IRQ_TYPE_LEVEL_HIGH:
	polarity \|= mask;
	fallthrough;
	case IRQ_TYPE_LEVEL_LOW:
	type \|= mask;
	break;

	default:
	return -EINVAL;
	}

	raw_spin_lock_irqsave(&ctrl->lock, flags);

	if (flow_type == IRQ_TYPE_EDGE_BOTH) {
	ctrl->both_edges \|= mask;
	polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
	} else {
	ctrl->both_edges &= ~mask;
	}

	/* As the IRQ configuration can't be loaded atomically we
	* have to disable the interrupt while the configuration state
	* is invalid.
	*/
	disabled = ath79_gpio_update_bits(
	ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);

	ath79_gpio_update_bits(
	ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type);
	ath79_gpio_update_bits(
	ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity);

	if (disabled)
	ath79_gpio_update_bits(
	ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);

	raw_spin_unlock_irqrestore(&ctrl->lock, flags);

	return 0;
	}

	static struct irq_chip ath79_gpio_irqchip = {
	.name = "gpio-ath79",
	.irq_enable = ath79_gpio_irq_enable,
	.irq_disable = ath79_gpio_irq_disable,
	.irq_mask = ath79_gpio_irq_mask,
	.irq_unmask = ath79_gpio_irq_unmask,
	.irq_set_type = ath79_gpio_irq_set_type,
	};

	static void ath79_gpio_irq_handler(struct irq_desc *desc)
	{
	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
	struct irq_chip *irqchip = irq_desc_get_chip(desc);
	struct ath79_gpio_ctrl *ctrl =
	container_of(gc, struct ath79_gpio_ctrl, gc);
	unsigned long flags, pending;
	u32 both_edges, state;
	int irq;

	chained_irq_enter(irqchip, desc);

	raw_spin_lock_irqsave(&ctrl->lock, flags);

	pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING);

	/* Update the polarity of the both edges irqs */
	both_edges = ctrl->both_edges & pending;
	if (both_edges) {
	state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
	ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY,
	both_edges, ~state);
	}

	raw_spin_unlock_irqrestore(&ctrl->lock, flags);

	if (pending) {
	for_each_set_bit(irq, &pending, gc->ngpio)
	generic_handle_irq(
	irq_linear_revmap(gc->irq.domain, irq));
	}

	chained_irq_exit(irqchip, desc);
	}

	static const struct of_device_id ath79_gpio_of_match[] = {
	{ .compatible = "qca,ar7100-gpio" },
	{ .compatible = "qca,ar9340-gpio" },
	{},
	};
	MODULE_DEVICE_TABLE(of, ath79_gpio_of_match);

	static int ath79_gpio_probe(struct platform_device *pdev)
	{
	struct ath79_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct ath79_gpio_ctrl *ctrl;
	struct gpio_irq_chip *girq;
	u32 ath79_gpio_count;
	bool oe_inverted;
	int err;

	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
	if (!ctrl)
	return -ENOMEM;

	if (np) {
	err = of_property_read_u32(np, "ngpios", &ath79_gpio_count);
	if (err) {
	dev_err(dev, "ngpios property is not valid\n");
	return err;
	}
	oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio");
	} else if (pdata) {
	ath79_gpio_count = pdata->ngpios;
	oe_inverted = pdata->oe_inverted;
	} else {
	dev_err(dev, "No DT node or platform data found\n");
	return -EINVAL;
	}

	if (ath79_gpio_count >= 32) {
	dev_err(dev, "ngpios must be less than 32\n");
	return -EINVAL;
	}

	ctrl->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(ctrl->base))
	return PTR_ERR(ctrl->base);

	raw_spin_lock_init(&ctrl->lock);
	err = bgpio_init(&ctrl->gc, dev, 4,
	ctrl->base + AR71XX_GPIO_REG_IN,
	ctrl->base + AR71XX_GPIO_REG_SET,
	ctrl->base + AR71XX_GPIO_REG_CLEAR,
	oe_inverted ? NULL : ctrl->base + AR71XX_GPIO_REG_OE,
	oe_inverted ? ctrl->base + AR71XX_GPIO_REG_OE : NULL,
	0);
	if (err) {
	dev_err(dev, "bgpio_init failed\n");
	return err;
	}
	/* Use base 0 to stay compatible with legacy platforms */
	ctrl->gc.base = 0;

	/* Optional interrupt setup */
	if (!np \|\| of_property_read_bool(np, "interrupt-controller")) {
	girq = &ctrl->gc.irq;
	girq->chip = &ath79_gpio_irqchip;
	girq->parent_handler = ath79_gpio_irq_handler;
	girq->num_parents = 1;
	girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
	GFP_KERNEL);
	if (!girq->parents)
	return -ENOMEM;
	girq->parents[0] = platform_get_irq(pdev, 0);
	girq->default_type = IRQ_TYPE_NONE;
	girq->handler = handle_simple_irq;
	}

	return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
	}

	static struct platform_driver ath79_gpio_driver = {
	.driver = {
	.name = "ath79-gpio",
	.of_match_table = ath79_gpio_of_match,
	},
	.probe = ath79_gpio_probe,
	};

	module_platform_driver(ath79_gpio_driver);

	MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X GPIO API support");
	MODULE_LICENSE("GPL v2");