summaryrefslogtreecommitdiff
path: root/drivers/irqchip/irq-goldfish-pic.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/irqchip/irq-goldfish-pic.c')
-rw-r--r--drivers/irqchip/irq-goldfish-pic.c139
1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-goldfish-pic.c b/drivers/irqchip/irq-goldfish-pic.c
new file mode 100644
index 000000000000..2a92f03c73e4
--- /dev/null
+++ b/drivers/irqchip/irq-goldfish-pic.c
@@ -0,0 +1,139 @@
+/*
+ * Driver for MIPS Goldfish Programmable Interrupt Controller.
+ *
+ * Author: Miodrag Dinic <miodrag.dinic@mips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#define GFPIC_NR_IRQS 32
+
+/* 8..39 Cascaded Goldfish PIC interrupts */
+#define GFPIC_IRQ_BASE 8
+
+#define GFPIC_REG_IRQ_PENDING 0x04
+#define GFPIC_REG_IRQ_DISABLE_ALL 0x08
+#define GFPIC_REG_IRQ_DISABLE 0x0c
+#define GFPIC_REG_IRQ_ENABLE 0x10
+
+struct goldfish_pic_data {
+ void __iomem *base;
+ struct irq_domain *irq_domain;
+};
+
+static void goldfish_pic_cascade(struct irq_desc *desc)
+{
+ struct goldfish_pic_data *gfpic = irq_desc_get_handler_data(desc);
+ struct irq_chip *host_chip = irq_desc_get_chip(desc);
+ u32 pending, hwirq, virq;
+
+ chained_irq_enter(host_chip, desc);
+
+ pending = readl(gfpic->base + GFPIC_REG_IRQ_PENDING);
+ while (pending) {
+ hwirq = __fls(pending);
+ virq = irq_linear_revmap(gfpic->irq_domain, hwirq);
+ generic_handle_irq(virq);
+ pending &= ~(1 << hwirq);
+ }
+
+ chained_irq_exit(host_chip, desc);
+}
+
+static const struct irq_domain_ops goldfish_irq_domain_ops = {
+ .xlate = irq_domain_xlate_onecell,
+};
+
+static int __init goldfish_pic_of_init(struct device_node *of_node,
+ struct device_node *parent)
+{
+ struct goldfish_pic_data *gfpic;
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+ unsigned int parent_irq;
+ int ret = 0;
+
+ gfpic = kzalloc(sizeof(*gfpic), GFP_KERNEL);
+ if (!gfpic) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ parent_irq = irq_of_parse_and_map(of_node, 0);
+ if (!parent_irq) {
+ pr_err("Failed to map parent IRQ!\n");
+ ret = -EINVAL;
+ goto out_free;
+ }
+
+ gfpic->base = of_iomap(of_node, 0);
+ if (!gfpic->base) {
+ pr_err("Failed to map base address!\n");
+ ret = -ENOMEM;
+ goto out_unmap_irq;
+ }
+
+ /* Mask interrupts. */
+ writel(1, gfpic->base + GFPIC_REG_IRQ_DISABLE_ALL);
+
+ gc = irq_alloc_generic_chip("GFPIC", 1, GFPIC_IRQ_BASE, gfpic->base,
+ handle_level_irq);
+ if (!gc) {
+ pr_err("Failed to allocate chip structures!\n");
+ ret = -ENOMEM;
+ goto out_iounmap;
+ }
+
+ ct = gc->chip_types;
+ ct->regs.enable = GFPIC_REG_IRQ_ENABLE;
+ ct->regs.disable = GFPIC_REG_IRQ_DISABLE;
+ ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
+ ct->chip.irq_mask = irq_gc_mask_disable_reg;
+
+ irq_setup_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS), 0,
+ IRQ_NOPROBE | IRQ_LEVEL, 0);
+
+ gfpic->irq_domain = irq_domain_add_legacy(of_node, GFPIC_NR_IRQS,
+ GFPIC_IRQ_BASE, 0,
+ &goldfish_irq_domain_ops,
+ NULL);
+ if (!gfpic->irq_domain) {
+ pr_err("Failed to add irqdomain!\n");
+ ret = -ENOMEM;
+ goto out_destroy_generic_chip;
+ }
+
+ irq_set_chained_handler_and_data(parent_irq,
+ goldfish_pic_cascade, gfpic);
+
+ pr_info("Successfully registered.\n");
+ return 0;
+
+out_destroy_generic_chip:
+ irq_destroy_generic_chip(gc, IRQ_MSK(GFPIC_NR_IRQS),
+ IRQ_NOPROBE | IRQ_LEVEL, 0);
+out_iounmap:
+ iounmap(gfpic->base);
+out_unmap_irq:
+ irq_dispose_mapping(parent_irq);
+out_free:
+ kfree(gfpic);
+out_err:
+ pr_err("Failed to initialize! (errno = %d)\n", ret);
+ return ret;
+}
+
+IRQCHIP_DECLARE(google_gf_pic, "google,goldfish-pic", goldfish_pic_of_init);