--- /dev/null
+/*
+ * Copyright (c) 2016 MediaTek Inc.
+ * Author: Youlin.Pei <youlin.pei@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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 recored 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);