1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-mtk-cirq.c b/drivers/irqchip/irq-mtk-cirq.c
new file mode 100644
index 000000000..9bca09180
--- /dev/null
+++ b/drivers/irqchip/irq-mtk-cirq.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016 MediaTek Inc.
+ * Author: Youlin.Pei <youlin.pei@mediatek.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/syscore_ops.h>
+
+#define CIRQ_ACK	0x40
+#define CIRQ_MASK_SET	0xc0
+#define CIRQ_MASK_CLR	0x100
+#define CIRQ_SENS_SET	0x180
+#define CIRQ_SENS_CLR	0x1c0
+#define CIRQ_POL_SET	0x240
+#define CIRQ_POL_CLR	0x280
+#define CIRQ_CONTROL	0x300
+
+#define CIRQ_EN	0x1
+#define CIRQ_EDGE	0x2
+#define CIRQ_FLUSH	0x4
+
+struct mtk_cirq_chip_data {
+	void __iomem *base;
+	unsigned int ext_irq_start;
+	unsigned int ext_irq_end;
+	struct irq_domain *domain;
+};
+
+static struct mtk_cirq_chip_data *cirq_data;
+
+static void mtk_cirq_write_mask(struct irq_data *data, unsigned int offset)
+{
+	struct mtk_cirq_chip_data *chip_data = data->chip_data;
+	unsigned int cirq_num = data->hwirq;
+	u32 mask = 1 << (cirq_num % 32);
+
+	writel_relaxed(mask, chip_data->base + offset + (cirq_num / 32) * 4);
+}
+
+static void mtk_cirq_mask(struct irq_data *data)
+{
+	mtk_cirq_write_mask(data, CIRQ_MASK_SET);
+	irq_chip_mask_parent(data);
+}
+
+static void mtk_cirq_unmask(struct irq_data *data)
+{
+	mtk_cirq_write_mask(data, CIRQ_MASK_CLR);
+	irq_chip_unmask_parent(data);
+}
+
+static int mtk_cirq_set_type(struct irq_data *data, unsigned int type)
+{
+	int ret;
+
+	switch (type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_EDGE_FALLING:
+		mtk_cirq_write_mask(data, CIRQ_POL_CLR);
+		mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		mtk_cirq_write_mask(data, CIRQ_POL_SET);
+		mtk_cirq_write_mask(data, CIRQ_SENS_CLR);
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		mtk_cirq_write_mask(data, CIRQ_POL_CLR);
+		mtk_cirq_write_mask(data, CIRQ_SENS_SET);
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		mtk_cirq_write_mask(data, CIRQ_POL_SET);
+		mtk_cirq_write_mask(data, CIRQ_SENS_SET);
+		break;
+	default:
+		break;
+	}
+
+	data = data->parent_data;
+	ret = data->chip->irq_set_type(data, type);
+	return ret;
+}
+
+static struct irq_chip mtk_cirq_chip = {
+	.name			= "MT_CIRQ",
+	.irq_mask		= mtk_cirq_mask,
+	.irq_unmask		= mtk_cirq_unmask,
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_set_type		= mtk_cirq_set_type,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+#endif
+};
+
+static int mtk_cirq_domain_translate(struct irq_domain *d,
+				     struct irq_fwspec *fwspec,
+				     unsigned long *hwirq,
+				     unsigned int *type)
+{
+	if (is_of_node(fwspec->fwnode)) {
+		if (fwspec->param_count != 3)
+			return -EINVAL;
+
+		/* No PPI should point to this domain */
+		if (fwspec->param[0] != 0)
+			return -EINVAL;
+
+		/* cirq support irq number check */
+		if (fwspec->param[1] < cirq_data->ext_irq_start ||
+		    fwspec->param[1] > cirq_data->ext_irq_end)
+			return -EINVAL;
+
+		*hwirq = fwspec->param[1] - cirq_data->ext_irq_start;
+		*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int mtk_cirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs, void *arg)
+{
+	int ret;
+	irq_hw_number_t hwirq;
+	unsigned int type;
+	struct irq_fwspec *fwspec = arg;
+	struct irq_fwspec parent_fwspec = *fwspec;
+
+	ret = mtk_cirq_domain_translate(domain, fwspec, &hwirq, &type);
+	if (ret)
+		return ret;
+
+	if (WARN_ON(nr_irqs != 1))
+		return -EINVAL;
+
+	irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
+				      &mtk_cirq_chip,
+				      domain->host_data);
+
+	parent_fwspec.fwnode = domain->parent->fwnode;
+	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
+					    &parent_fwspec);
+}
+
+static const struct irq_domain_ops cirq_domain_ops = {
+	.translate	= mtk_cirq_domain_translate,
+	.alloc		= mtk_cirq_domain_alloc,
+	.free		= irq_domain_free_irqs_common,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_cirq_suspend(void)
+{
+	u32 value, mask;
+	unsigned int irq, hwirq_num;
+	bool pending, masked;
+	int i, pendret, maskret;
+
+	/*
+	 * When external interrupts happened, CIRQ will record the status
+	 * even CIRQ is not enabled. When execute flush command, CIRQ will
+	 * resend the signals according to the status. So if don't clear the
+	 * status, CIRQ will resend the wrong signals.
+	 *
+	 * arch_suspend_disable_irqs() will be called before CIRQ suspend
+	 * callback. If clear all the status simply, the external interrupts
+	 * which happened between arch_suspend_disable_irqs and CIRQ suspend
+	 * callback will be lost. Using following steps to avoid this issue;
+	 *
+	 * - Iterate over all the CIRQ supported interrupts;
+	 * - For each interrupt, inspect its pending and masked status at GIC
+	 *   level;
+	 * - If pending and unmasked, it happened between
+	 *   arch_suspend_disable_irqs and CIRQ suspend callback, don't ACK
+	 *   it. Otherwise, ACK it.
+	 */
+	hwirq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
+	for (i = 0; i < hwirq_num; i++) {
+		irq = irq_find_mapping(cirq_data->domain, i);
+		if (irq) {
+			pendret = irq_get_irqchip_state(irq,
+							IRQCHIP_STATE_PENDING,
+							&pending);
+
+			maskret = irq_get_irqchip_state(irq,
+							IRQCHIP_STATE_MASKED,
+							&masked);
+
+			if (pendret == 0 && maskret == 0 &&
+			    (pending && !masked))
+				continue;
+		}
+
+		mask = 1 << (i % 32);
+		writel_relaxed(mask, cirq_data->base + CIRQ_ACK + (i / 32) * 4);
+	}
+
+	/* set edge_only mode, record edge-triggerd interrupts */
+	/* enable cirq */
+	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
+	value |= (CIRQ_EDGE | CIRQ_EN);
+	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
+
+	return 0;
+}
+
+static void mtk_cirq_resume(void)
+{
+	u32 value;
+
+	/* flush recorded interrupts, will send signals to parent controller */
+	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
+	writel_relaxed(value | CIRQ_FLUSH, cirq_data->base + CIRQ_CONTROL);
+
+	/* disable cirq */
+	value = readl_relaxed(cirq_data->base + CIRQ_CONTROL);
+	value &= ~(CIRQ_EDGE | CIRQ_EN);
+	writel_relaxed(value, cirq_data->base + CIRQ_CONTROL);
+}
+
+static struct syscore_ops mtk_cirq_syscore_ops = {
+	.suspend	= mtk_cirq_suspend,
+	.resume		= mtk_cirq_resume,
+};
+
+static void mtk_cirq_syscore_init(void)
+{
+	register_syscore_ops(&mtk_cirq_syscore_ops);
+}
+#else
+static inline void mtk_cirq_syscore_init(void) {}
+#endif
+
+static int __init mtk_cirq_of_init(struct device_node *node,
+				   struct device_node *parent)
+{
+	struct irq_domain *domain, *domain_parent;
+	unsigned int irq_num;
+	int ret;
+
+	domain_parent = irq_find_host(parent);
+	if (!domain_parent) {
+		pr_err("mtk_cirq: interrupt-parent not found\n");
+		return -EINVAL;
+	}
+
+	cirq_data = kzalloc(sizeof(*cirq_data), GFP_KERNEL);
+	if (!cirq_data)
+		return -ENOMEM;
+
+	cirq_data->base = of_iomap(node, 0);
+	if (!cirq_data->base) {
+		pr_err("mtk_cirq: unable to map cirq register\n");
+		ret = -ENXIO;
+		goto out_free;
+	}
+
+	ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 0,
+					 &cirq_data->ext_irq_start);
+	if (ret)
+		goto out_unmap;
+
+	ret = of_property_read_u32_index(node, "mediatek,ext-irq-range", 1,
+					 &cirq_data->ext_irq_end);
+	if (ret)
+		goto out_unmap;
+
+	irq_num = cirq_data->ext_irq_end - cirq_data->ext_irq_start + 1;
+	domain = irq_domain_add_hierarchy(domain_parent, 0,
+					  irq_num, node,
+					  &cirq_domain_ops, cirq_data);
+	if (!domain) {
+		ret = -ENOMEM;
+		goto out_unmap;
+	}
+	cirq_data->domain = domain;
+
+	mtk_cirq_syscore_init();
+
+	return 0;
+
+out_unmap:
+	iounmap(cirq_data->base);
+out_free:
+	kfree(cirq_data);
+	return ret;
+}
+
+IRQCHIP_DECLARE(mtk_cirq, "mediatek,mtk-cirq", mtk_cirq_of_init);