1 files changed, 295 insertions, 0 deletions

diff --git a/drivers/irqchip/irq-brcmstb-l2.c b/drivers/irqchip/irq-brcmstb-l2.c
new file mode 100644
index 0000000000..5559c943f0
--- /dev/null
+++ b/drivers/irqchip/irq-brcmstb-l2.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic Broadcom Set Top Box Level 2 Interrupt controller driver
+ *
+ * Copyright (C) 2014-2017 Broadcom
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME	": " fmt
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.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/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+
+struct brcmstb_intc_init_params {
+	irq_flow_handler_t handler;
+	int cpu_status;
+	int cpu_clear;
+	int cpu_mask_status;
+	int cpu_mask_set;
+	int cpu_mask_clear;
+};
+
+/* Register offsets in the L2 latched interrupt controller */
+static const struct brcmstb_intc_init_params l2_edge_intc_init = {
+	.handler		= handle_edge_irq,
+	.cpu_status		= 0x00,
+	.cpu_clear		= 0x08,
+	.cpu_mask_status	= 0x0c,
+	.cpu_mask_set		= 0x10,
+	.cpu_mask_clear		= 0x14
+};
+
+/* Register offsets in the L2 level interrupt controller */
+static const struct brcmstb_intc_init_params l2_lvl_intc_init = {
+	.handler		= handle_level_irq,
+	.cpu_status		= 0x00,
+	.cpu_clear		= -1, /* Register not present */
+	.cpu_mask_status	= 0x04,
+	.cpu_mask_set		= 0x08,
+	.cpu_mask_clear		= 0x0C
+};
+
+/* L2 intc private data structure */
+struct brcmstb_l2_intc_data {
+	struct irq_domain *domain;
+	struct irq_chip_generic *gc;
+	int status_offset;
+	int mask_offset;
+	bool can_wake;
+	u32 saved_mask; /* for suspend/resume */
+};
+
+/**
+ * brcmstb_l2_mask_and_ack - Mask and ack pending interrupt
+ * @d: irq_data
+ *
+ * Chip has separate enable/disable registers instead of a single mask
+ * register and pending interrupt is acknowledged by setting a bit.
+ *
+ * Note: This function is generic and could easily be added to the
+ * generic irqchip implementation if there ever becomes a will to do so.
+ * Perhaps with a name like irq_gc_mask_disable_and_ack_set().
+ *
+ * e.g.: https://patchwork.kernel.org/patch/9831047/
+ */
+static void brcmstb_l2_mask_and_ack(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+	u32 mask = d->mask;
+
+	irq_gc_lock(gc);
+	irq_reg_writel(gc, mask, ct->regs.disable);
+	*ct->mask_cache &= ~mask;
+	irq_reg_writel(gc, mask, ct->regs.ack);
+	irq_gc_unlock(gc);
+}
+
+static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)
+{
+	struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned int irq;
+	u32 status;
+
+	chained_irq_enter(chip, desc);
+
+	status = irq_reg_readl(b->gc, b->status_offset) &
+		~(irq_reg_readl(b->gc, b->mask_offset));
+
+	if (status == 0) {
+		raw_spin_lock(&desc->lock);
+		handle_bad_irq(desc);
+		raw_spin_unlock(&desc->lock);
+		goto out;
+	}
+
+	do {
+		irq = ffs(status) - 1;
+		status &= ~(1 << irq);
+		generic_handle_domain_irq(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 irq_chip_type *ct = irq_data_get_chip_type(d);
+	struct brcmstb_l2_intc_data *b = gc->private;
+	unsigned long flags;
+
+	irq_gc_lock_irqsave(gc, flags);
+	/* Save the current mask */
+	b->saved_mask = irq_reg_readl(gc, ct->regs.mask);
+
+	if (b->can_wake) {
+		/* Program the wakeup mask */
+		irq_reg_writel(gc, ~gc->wake_active, ct->regs.disable);
+		irq_reg_writel(gc, gc->wake_active, ct->regs.enable);
+	}
+	irq_gc_unlock_irqrestore(gc, flags);
+}
+
+static void brcmstb_l2_intc_resume(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct irq_chip_type *ct = irq_data_get_chip_type(d);
+	struct brcmstb_l2_intc_data *b = gc->private;
+	unsigned long flags;
+
+	irq_gc_lock_irqsave(gc, flags);
+	if (ct->chip.irq_ack) {
+		/* Clear unmasked non-wakeup interrupts */
+		irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active,
+				ct->regs.ack);
+	}
+
+	/* Restore the saved mask */
+	irq_reg_writel(gc, b->saved_mask, ct->regs.disable);
+	irq_reg_writel(gc, ~b->saved_mask, ct->regs.enable);
+	irq_gc_unlock_irqrestore(gc, flags);
+}
+
+static int __init brcmstb_l2_intc_of_init(struct device_node *np,
+					  struct device_node *parent,
+					  const struct brcmstb_intc_init_params
+					  *init_params)
+{
+	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+	unsigned int set = 0;
+	struct brcmstb_l2_intc_data *data;
+	struct irq_chip_type *ct;
+	int ret;
+	unsigned int flags;
+	int parent_irq;
+	void __iomem *base;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	base = of_iomap(np, 0);
+	if (!base) {
+		pr_err("failed to remap intc L2 registers\n");
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	/* Disable all interrupts by default */
+	writel(0xffffffff, base + init_params->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 && (init_params->cpu_clear >= 0))
+		writel(0xffffffff, base + init_params->cpu_clear);
+
+	parent_irq = irq_of_parse_and_map(np, 0);
+	if (!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;
+
+	if (init_params->handler == handle_level_irq)
+		set |= IRQ_LEVEL;
+
+	/* Allocate a single Generic IRQ chip for this node */
+	ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
+			np->full_name, init_params->handler, clr, set, flags);
+	if (ret) {
+		pr_err("failed to allocate generic irq chip\n");
+		goto out_free_domain;
+	}
+
+	/* Set the IRQ chaining logic */
+	irq_set_chained_handler_and_data(parent_irq,
+					 brcmstb_l2_intc_irq_handle, data);
+
+	data->gc = irq_get_domain_generic_chip(data->domain, 0);
+	data->gc->reg_base = base;
+	data->gc->private = data;
+	data->status_offset = init_params->cpu_status;
+	data->mask_offset = init_params->cpu_mask_status;
+
+	ct = data->gc->chip_types;
+
+	if (init_params->cpu_clear >= 0) {
+		ct->regs.ack = init_params->cpu_clear;
+		ct->chip.irq_ack = irq_gc_ack_set_bit;
+		ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack;
+	} else {
+		/* No Ack - but still slightly more efficient to define this */
+		ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
+	}
+
+	ct->chip.irq_mask = irq_gc_mask_disable_reg;
+	ct->regs.disable = init_params->cpu_mask_set;
+	ct->regs.mask = init_params->cpu_mask_status;
+
+	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
+	ct->regs.enable = init_params->cpu_mask_clear;
+
+	ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
+	ct->chip.irq_resume = brcmstb_l2_intc_resume;
+	ct->chip.irq_pm_shutdown = brcmstb_l2_intc_suspend;
+
+	if (data->can_wake) {
+		/* This IRQ chip can wake the system, set all child interrupts
+		 * in wake_enabled mask
+		 */
+		data->gc->wake_enabled = 0xffffffff;
+		ct->chip.irq_set_wake = irq_gc_set_wake;
+		enable_irq_wake(parent_irq);
+	}
+
+	pr_info("registered L2 intc (%pOF, parent irq: %d)\n", np, parent_irq);
+
+	return 0;
+
+out_free_domain:
+	irq_domain_remove(data->domain);
+out_unmap:
+	iounmap(base);
+out_free:
+	kfree(data);
+	return ret;
+}
+
+static int __init brcmstb_l2_edge_intc_of_init(struct device_node *np,
+	struct device_node *parent)
+{
+	return brcmstb_l2_intc_of_init(np, parent, &l2_edge_intc_init);
+}
+
+static int __init brcmstb_l2_lvl_intc_of_init(struct device_node *np,
+	struct device_node *parent)
+{
+	return brcmstb_l2_intc_of_init(np, parent, &l2_lvl_intc_init);
+}
+
+IRQCHIP_PLATFORM_DRIVER_BEGIN(brcmstb_l2)
+IRQCHIP_MATCH("brcm,l2-intc", brcmstb_l2_edge_intc_of_init)
+IRQCHIP_MATCH("brcm,hif-spi-l2-intc", brcmstb_l2_edge_intc_of_init)
+IRQCHIP_MATCH("brcm,upg-aux-aon-l2-intc", brcmstb_l2_edge_intc_of_init)
+IRQCHIP_MATCH("brcm,bcm7271-l2-intc", brcmstb_l2_lvl_intc_of_init)
+IRQCHIP_PLATFORM_DRIVER_END(brcmstb_l2)
+MODULE_DESCRIPTION("Broadcom STB generic L2 interrupt controller");
+MODULE_LICENSE("GPL v2");