1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Atheros AR71xx/AR724x/AR913x specific interrupt handling
4 *
5 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
6 * Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
7 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
8 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
9 *
10 * Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
11 */
12
13#include <linux/interrupt.h>
14#include <linux/irqchip.h>
15#include <linux/of.h>
16
17#include <asm/irq_cpu.h>
18#include <asm/mach-ath79/ath79.h>
19
20/*
21 * The IP2/IP3 lines are tied to a PCI/WMAC/USB device. Drivers for
22 * these devices typically allocate coherent DMA memory, however the
23 * DMA controller may still have some unsynchronized data in the FIFO.
24 * Issue a flush in the handlers to ensure that the driver sees
25 * the update.
26 *
27 * This array map the interrupt lines to the DDR write buffer channels.
28 */
29
30static unsigned irq_wb_chan[8] = {
31 -1, -1, -1, -1, -1, -1, -1, -1,
32};
33
34asmlinkage void plat_irq_dispatch(void)
35{
36 unsigned long pending;
37 int irq;
38
39 pending = read_c0_status() & read_c0_cause() & ST0_IM;
40
41 if (!pending) {
42 spurious_interrupt();
43 return;
44 }
45
46 pending >>= CAUSEB_IP;
47 while (pending) {
48 irq = fls(x: pending) - 1;
49 if (irq < ARRAY_SIZE(irq_wb_chan) && irq_wb_chan[irq] != -1)
50 ath79_ddr_wb_flush(irq_wb_chan[irq]);
51 do_IRQ(MIPS_CPU_IRQ_BASE + irq);
52 pending &= ~BIT(irq);
53 }
54}
55
56static int __init ar79_cpu_intc_of_init(
57 struct device_node *node, struct device_node *parent)
58{
59 int err, i, count;
60
61 /* Fill the irq_wb_chan table */
62 count = of_count_phandle_with_args(
63 np: node, list_name: "qca,ddr-wb-channels", cells_name: "#qca,ddr-wb-channel-cells");
64
65 for (i = 0; i < count; i++) {
66 struct of_phandle_args args;
67 u32 irq = i;
68
69 of_property_read_u32_index(
70 np: node, propname: "qca,ddr-wb-channel-interrupts", index: i, out_value: &irq);
71 if (irq >= ARRAY_SIZE(irq_wb_chan))
72 continue;
73
74 err = of_parse_phandle_with_args(
75 np: node, list_name: "qca,ddr-wb-channels",
76 cells_name: "#qca,ddr-wb-channel-cells",
77 index: i, out_args: &args);
78 if (err)
79 return err;
80
81 irq_wb_chan[irq] = args.args[0];
82 }
83
84 return mips_cpu_irq_of_init(node, parent);
85}
86IRQCHIP_DECLARE(ar79_cpu_intc, "qca,ar7100-cpu-intc",
87 ar79_cpu_intc_of_init);
88
89void __init ath79_cpu_irq_init(unsigned irq_wb_chan2, unsigned irq_wb_chan3)
90{
91 irq_wb_chan[2] = irq_wb_chan2;
92 irq_wb_chan[3] = irq_wb_chan3;
93 mips_cpu_irq_init();
94}
95

source code of linux/drivers/irqchip/irq-ath79-cpu.c