1 /*
2 * Atheros AR71xx/AR724x/AR913x specific interrupt handling
3 *
4 * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
5 * Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
6 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
7 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
8 *
9 * Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License version 2 as published
13 * by the Free Software Foundation.
14 */
15
16 #include <linux/interrupt.h>
17 #include <linux/irqchip.h>
18 #include <linux/of.h>
19
20 #include <asm/irq_cpu.h>
21 #include <asm/mach-ath79/ath79.h>
22
23 /*
24 * The IP2/IP3 lines are tied to a PCI/WMAC/USB device. Drivers for
25 * these devices typically allocate coherent DMA memory, however the
26 * DMA controller may still have some unsynchronized data in the FIFO.
27 * Issue a flush in the handlers to ensure that the driver sees
28 * the update.
29 *
30 * This array map the interrupt lines to the DDR write buffer channels.
31 */
32
33 static unsigned irq_wb_chan[8] = {
34 -1, -1, -1, -1, -1, -1, -1, -1,
35 };
36
plat_irq_dispatch(void)37 asmlinkage void plat_irq_dispatch(void)
38 {
39 unsigned long pending;
40 int irq;
41
42 pending = read_c0_status() & read_c0_cause() & ST0_IM;
43
44 if (!pending) {
45 spurious_interrupt();
46 return;
47 }
48
49 pending >>= CAUSEB_IP;
50 while (pending) {
51 irq = fls(pending) - 1;
52 if (irq < ARRAY_SIZE(irq_wb_chan) && irq_wb_chan[irq] != -1)
53 ath79_ddr_wb_flush(irq_wb_chan[irq]);
54 do_IRQ(MIPS_CPU_IRQ_BASE + irq);
55 pending &= ~BIT(irq);
56 }
57 }
58
ar79_cpu_intc_of_init(struct device_node * node,struct device_node * parent)59 static int __init ar79_cpu_intc_of_init(
60 struct device_node *node, struct device_node *parent)
61 {
62 int err, i, count;
63
64 /* Fill the irq_wb_chan table */
65 count = of_count_phandle_with_args(
66 node, "qca,ddr-wb-channels", "#qca,ddr-wb-channel-cells");
67
68 for (i = 0; i < count; i++) {
69 struct of_phandle_args args;
70 u32 irq = i;
71
72 of_property_read_u32_index(
73 node, "qca,ddr-wb-channel-interrupts", i, &irq);
74 if (irq >= ARRAY_SIZE(irq_wb_chan))
75 continue;
76
77 err = of_parse_phandle_with_args(
78 node, "qca,ddr-wb-channels",
79 "#qca,ddr-wb-channel-cells",
80 i, &args);
81 if (err)
82 return err;
83
84 irq_wb_chan[irq] = args.args[0];
85 }
86
87 return mips_cpu_irq_of_init(node, parent);
88 }
89 IRQCHIP_DECLARE(ar79_cpu_intc, "qca,ar7100-cpu-intc",
90 ar79_cpu_intc_of_init);
91
ath79_cpu_irq_init(unsigned irq_wb_chan2,unsigned irq_wb_chan3)92 void __init ath79_cpu_irq_init(unsigned irq_wb_chan2, unsigned irq_wb_chan3)
93 {
94 irq_wb_chan[2] = irq_wb_chan2;
95 irq_wb_chan[3] = irq_wb_chan3;
96 mips_cpu_irq_init();
97 }
98