--- /dev/null
+/*
+ * Generic Broadcom Set Top Box Level 2 Interrupt controller driver
+ *
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kconfig.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+
+#include "irqchip.h"
+
+/* Register offsets in the L2 interrupt controller */
+#define CPU_STATUS 0x00
+#define CPU_SET 0x04
+#define CPU_CLEAR 0x08
+#define CPU_MASK_STATUS 0x0c
+#define CPU_MASK_SET 0x10
+#define CPU_MASK_CLEAR 0x14
+
+/* L2 intc private data structure */
+struct brcmstb_l2_intc_data {
+ int parent_irq;
+ void __iomem *base;
+ struct irq_domain *domain;
+ bool can_wake;
+ u32 saved_mask; /* for suspend/resume */
+};
+
+static void brcmstb_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)
+{
+ struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
+ struct irq_chip_generic *gc = irq_get_domain_generic_chip(b->domain, 0);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ u32 status;
+
+ chained_irq_enter(chip, desc);
+
+ status = irq_reg_readl(gc, CPU_STATUS) &
+ ~(irq_reg_readl(gc, CPU_MASK_STATUS));
+
+ if (status == 0) {
+ raw_spin_lock(&desc->lock);
+ handle_bad_irq(irq, desc);
+ raw_spin_unlock(&desc->lock);
+ goto out;
+ }
+
+ do {
+ irq = ffs(status) - 1;
+ /* ack at our level */
+ irq_reg_writel(gc, 1 << irq, CPU_CLEAR);
+ status &= ~(1 << irq);
+ generic_handle_irq(irq_find_mapping(b->domain, irq));
+ } while (status);
+out:
+ chained_irq_exit(chip, desc);
+}
+
+static void brcmstb_l2_intc_suspend(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct brcmstb_l2_intc_data *b = gc->private;
+
+ irq_gc_lock(gc);
+ /* Save the current mask */
+ b->saved_mask = irq_reg_readl(gc, CPU_MASK_STATUS);
+
+ if (b->can_wake) {
+ /* Program the wakeup mask */
+ irq_reg_writel(gc, ~gc->wake_active, CPU_MASK_SET);
+ irq_reg_writel(gc, gc->wake_active, CPU_MASK_CLEAR);
+ }
+ irq_gc_unlock(gc);
+}
+
+static void brcmstb_l2_intc_resume(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct brcmstb_l2_intc_data *b = gc->private;
+
+ irq_gc_lock(gc);
+ /* Clear unmasked non-wakeup interrupts */
+ irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active, CPU_CLEAR);
+
+ /* Restore the saved mask */
+ irq_reg_writel(gc, b->saved_mask, CPU_MASK_SET);
+ irq_reg_writel(gc, ~b->saved_mask, CPU_MASK_CLEAR);
+ irq_gc_unlock(gc);
+}
+
+int __init brcmstb_l2_intc_of_init(struct device_node *np,
+ struct device_node *parent)
+{
+ unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+ struct brcmstb_l2_intc_data *data;
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+ int ret;
+ unsigned int flags;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->base = of_iomap(np, 0);
+ if (!data->base) {
+ pr_err("failed to remap intc L2 registers\n");
+ ret = -ENOMEM;
+ goto out_free;
+ }
+
+ /* Disable all interrupts by default */
+ writel(0xffffffff, data->base + CPU_MASK_SET);
+
+ /* Wakeup interrupts may be retained from S5 (cold boot) */
+ data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
+ if (!data->can_wake)
+ writel(0xffffffff, data->base + CPU_CLEAR);
+
+ data->parent_irq = irq_of_parse_and_map(np, 0);
+ if (!data->parent_irq) {
+ pr_err("failed to find parent interrupt\n");
+ ret = -EINVAL;
+ goto out_unmap;
+ }
+
+ data->domain = irq_domain_add_linear(np, 32,
+ &irq_generic_chip_ops, NULL);
+ if (!data->domain) {
+ ret = -ENOMEM;
+ goto out_unmap;
+ }
+
+ /* MIPS chips strapped for BE will automagically configure the
+ * peripheral registers for CPU-native byte order.
+ */
+ flags = 0;
+ if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+ flags |= IRQ_GC_BE_IO;
+
+ /* Allocate a single Generic IRQ chip for this node */
+ ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
+ np->full_name, handle_edge_irq, clr, 0, flags);
+ if (ret) {
+ pr_err("failed to allocate generic irq chip\n");
+ goto out_free_domain;
+ }
+
+ /* Set the IRQ chaining logic */
+ irq_set_handler_data(data->parent_irq, data);
+ irq_set_chained_handler(data->parent_irq, brcmstb_l2_intc_irq_handle);
+
+ gc = irq_get_domain_generic_chip(data->domain, 0);
+ gc->reg_base = data->base;
+ gc->private = data;
+ ct = gc->chip_types;
+
+ ct->chip.irq_ack = irq_gc_ack_set_bit;
+ ct->regs.ack = CPU_CLEAR;
+
+ ct->chip.irq_mask = irq_gc_mask_disable_reg;
+ ct->regs.disable = CPU_MASK_SET;
+
+ ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
+ ct->regs.enable = CPU_MASK_CLEAR;
+
+ ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
+ ct->chip.irq_resume = brcmstb_l2_intc_resume;
+
+ if (data->can_wake) {
+ /* This IRQ chip can wake the system, set all child interrupts
+ * in wake_enabled mask
+ */
+ gc->wake_enabled = 0xffffffff;
+ ct->chip.irq_set_wake = irq_gc_set_wake;
+ }
+
+ pr_info("registered L2 intc (mem: 0x%p, parent irq: %d)\n",
+ data->base, data->parent_irq);
+
+ return 0;
+
+out_free_domain:
+ irq_domain_remove(data->domain);
+out_unmap:
+ iounmap(data->base);
+out_free:
+ kfree(data);
+ return ret;
+}
+IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_intc_of_init);
Code Review / kvmfornfv.git / blobdiff