1 files changed, 312 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-ath79.c b/drivers/gpio/gpio-ath79.c
new file mode 100644
index 000000000..d5359341c
--- /dev/null
+++ b/drivers/gpio/gpio-ath79.c
@@ -0,0 +1,312 @@
+// 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;
+	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;
+	platform_set_drvdata(pdev, ctrl);
+
+	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;
+	}
+
+	err = devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
+	if (err) {
+		dev_err(dev,
+			"cannot add AR71xx GPIO chip, error=%d", err);
+		return err;
+	}
+	return 0;
+}
+
+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");