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Simon Arlott89214f02012-09-12 19:57:26 -06001/*
2 * Copyright 2010 Broadcom
3 * Copyright 2012 Simon Arlott, Chris Boot, Stephen Warren
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * Quirk 1: Shortcut interrupts don't set the bank 1/2 register pending bits
16 *
17 * If an interrupt fires on bank 1 that isn't in the shortcuts list, bit 8
18 * on bank 0 is set to signify that an interrupt in bank 1 has fired, and
19 * to look in the bank 1 status register for more information.
20 *
21 * If an interrupt fires on bank 1 that _is_ in the shortcuts list, its
22 * shortcut bit in bank 0 is set as well as its interrupt bit in the bank 1
23 * status register, but bank 0 bit 8 is _not_ set.
24 *
25 * Quirk 2: You can't mask the register 1/2 pending interrupts
26 *
27 * In a proper cascaded interrupt controller, the interrupt lines with
28 * cascaded interrupt controllers on them are just normal interrupt lines.
29 * You can mask the interrupts and get on with things. With this controller
30 * you can't do that.
31 *
32 * Quirk 3: The shortcut interrupts can't be (un)masked in bank 0
33 *
34 * Those interrupts that have shortcuts can only be masked/unmasked in
35 * their respective banks' enable/disable registers. Doing so in the bank 0
36 * enable/disable registers has no effect.
37 *
38 * The FIQ control register:
39 * Bits 0-6: IRQ (index in order of interrupts from banks 1, 2, then 0)
40 * Bit 7: Enable FIQ generation
41 * Bits 8+: Unused
42 *
43 * An interrupt must be disabled before configuring it for FIQ generation
44 * otherwise both handlers will fire at the same time!
45 */
46
47#include <linux/io.h>
48#include <linux/slab.h>
49#include <linux/of_address.h>
50#include <linux/of_irq.h>
Joel Porquet41a83e02015-07-07 17:11:46 -040051#include <linux/irqchip.h>
Simon Arlott89214f02012-09-12 19:57:26 -060052#include <linux/irqdomain.h>
Simon Arlott89214f02012-09-12 19:57:26 -060053
54#include <asm/exception.h>
Axel Lin57029412013-07-05 00:31:36 +080055#include <asm/mach/irq.h>
56
Simon Arlott89214f02012-09-12 19:57:26 -060057/* Put the bank and irq (32 bits) into the hwirq */
58#define MAKE_HWIRQ(b, n) ((b << 5) | (n))
59#define HWIRQ_BANK(i) (i >> 5)
60#define HWIRQ_BIT(i) BIT(i & 0x1f)
61
62#define NR_IRQS_BANK0 8
63#define BANK0_HWIRQ_MASK 0xff
64/* Shortcuts can't be disabled so any unknown new ones need to be masked */
65#define SHORTCUT1_MASK 0x00007c00
66#define SHORTCUT2_MASK 0x001f8000
67#define SHORTCUT_SHIFT 10
68#define BANK1_HWIRQ BIT(8)
69#define BANK2_HWIRQ BIT(9)
70#define BANK0_VALID_MASK (BANK0_HWIRQ_MASK | BANK1_HWIRQ | BANK2_HWIRQ \
71 | SHORTCUT1_MASK | SHORTCUT2_MASK)
72
73#define REG_FIQ_CONTROL 0x0c
74
75#define NR_BANKS 3
76#define IRQS_PER_BANK 32
77
Nicolas Pitrec3760232015-07-24 15:24:45 -040078static const int reg_pending[] __initconst = { 0x00, 0x04, 0x08 };
79static const int reg_enable[] __initconst = { 0x18, 0x10, 0x14 };
80static const int reg_disable[] __initconst = { 0x24, 0x1c, 0x20 };
81static const int bank_irqs[] __initconst = { 8, 32, 32 };
Simon Arlott89214f02012-09-12 19:57:26 -060082
83static const int shortcuts[] = {
84 7, 9, 10, 18, 19, /* Bank 1 */
85 21, 22, 23, 24, 25, 30 /* Bank 2 */
86};
87
88struct armctrl_ic {
89 void __iomem *base;
90 void __iomem *pending[NR_BANKS];
91 void __iomem *enable[NR_BANKS];
92 void __iomem *disable[NR_BANKS];
93 struct irq_domain *domain;
94};
95
96static struct armctrl_ic intc __read_mostly;
Stephen Boyd8783dd32014-03-04 16:40:30 -080097static void __exception_irq_entry bcm2835_handle_irq(
Axel Lin57029412013-07-05 00:31:36 +080098 struct pt_regs *regs);
Eric Anholta493f332015-08-06 16:00:31 -070099static void bcm2836_chained_handle_irq(unsigned int irq, struct irq_desc *desc);
Simon Arlott89214f02012-09-12 19:57:26 -0600100
101static void armctrl_mask_irq(struct irq_data *d)
102{
103 writel_relaxed(HWIRQ_BIT(d->hwirq), intc.disable[HWIRQ_BANK(d->hwirq)]);
104}
105
106static void armctrl_unmask_irq(struct irq_data *d)
107{
108 writel_relaxed(HWIRQ_BIT(d->hwirq), intc.enable[HWIRQ_BANK(d->hwirq)]);
109}
110
111static struct irq_chip armctrl_chip = {
112 .name = "ARMCTRL-level",
113 .irq_mask = armctrl_mask_irq,
114 .irq_unmask = armctrl_unmask_irq
115};
116
117static int armctrl_xlate(struct irq_domain *d, struct device_node *ctrlr,
118 const u32 *intspec, unsigned int intsize,
119 unsigned long *out_hwirq, unsigned int *out_type)
120{
121 if (WARN_ON(intsize != 2))
122 return -EINVAL;
123
124 if (WARN_ON(intspec[0] >= NR_BANKS))
125 return -EINVAL;
126
127 if (WARN_ON(intspec[1] >= IRQS_PER_BANK))
128 return -EINVAL;
129
130 if (WARN_ON(intspec[0] == 0 && intspec[1] >= NR_IRQS_BANK0))
131 return -EINVAL;
132
133 *out_hwirq = MAKE_HWIRQ(intspec[0], intspec[1]);
134 *out_type = IRQ_TYPE_NONE;
135 return 0;
136}
137
Krzysztof Kozlowski96009732015-04-27 21:54:24 +0900138static const struct irq_domain_ops armctrl_ops = {
Simon Arlott89214f02012-09-12 19:57:26 -0600139 .xlate = armctrl_xlate
140};
141
142static int __init armctrl_of_init(struct device_node *node,
Eric Anholta493f332015-08-06 16:00:31 -0700143 struct device_node *parent,
144 bool is_2836)
Simon Arlott89214f02012-09-12 19:57:26 -0600145{
146 void __iomem *base;
147 int irq, b, i;
148
149 base = of_iomap(node, 0);
150 if (!base)
151 panic("%s: unable to map IC registers\n",
152 node->full_name);
153
154 intc.domain = irq_domain_add_linear(node, MAKE_HWIRQ(NR_BANKS, 0),
155 &armctrl_ops, NULL);
156 if (!intc.domain)
157 panic("%s: unable to create IRQ domain\n", node->full_name);
158
159 for (b = 0; b < NR_BANKS; b++) {
160 intc.pending[b] = base + reg_pending[b];
161 intc.enable[b] = base + reg_enable[b];
162 intc.disable[b] = base + reg_disable[b];
163
164 for (i = 0; i < bank_irqs[b]; i++) {
165 irq = irq_create_mapping(intc.domain, MAKE_HWIRQ(b, i));
166 BUG_ON(irq <= 0);
167 irq_set_chip_and_handler(irq, &armctrl_chip,
168 handle_level_irq);
169 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
170 }
171 }
Axel Lin57029412013-07-05 00:31:36 +0800172
Eric Anholta493f332015-08-06 16:00:31 -0700173 if (is_2836) {
174 int parent_irq = irq_of_parse_and_map(node, 0);
175
176 if (!parent_irq) {
177 panic("%s: unable to get parent interrupt.\n",
178 node->full_name);
179 }
180 irq_set_chained_handler(parent_irq, bcm2836_chained_handle_irq);
181 } else {
182 set_handle_irq(bcm2835_handle_irq);
183 }
184
Simon Arlott89214f02012-09-12 19:57:26 -0600185 return 0;
186}
187
Eric Anholta493f332015-08-06 16:00:31 -0700188static int __init bcm2835_armctrl_of_init(struct device_node *node,
189 struct device_node *parent)
190{
191 return armctrl_of_init(node, parent, false);
192}
193
194static int __init bcm2836_armctrl_of_init(struct device_node *node,
195 struct device_node *parent)
196{
197 return armctrl_of_init(node, parent, true);
198}
199
200
Simon Arlott89214f02012-09-12 19:57:26 -0600201/*
202 * Handle each interrupt across the entire interrupt controller. This reads the
203 * status register before handling each interrupt, which is necessary given that
204 * handle_IRQ may briefly re-enable interrupts for soft IRQ handling.
205 */
206
Eric Anholtde58e522015-08-06 16:00:30 -0700207static u32 armctrl_translate_bank(int bank)
Simon Arlott89214f02012-09-12 19:57:26 -0600208{
Eric Anholtde58e522015-08-06 16:00:30 -0700209 u32 stat = readl_relaxed(intc.pending[bank]);
Simon Arlott89214f02012-09-12 19:57:26 -0600210
Eric Anholtde58e522015-08-06 16:00:30 -0700211 return MAKE_HWIRQ(bank, ffs(stat) - 1);
Simon Arlott89214f02012-09-12 19:57:26 -0600212}
213
Eric Anholtde58e522015-08-06 16:00:30 -0700214static u32 armctrl_translate_shortcut(int bank, u32 stat)
Simon Arlott89214f02012-09-12 19:57:26 -0600215{
Eric Anholtde58e522015-08-06 16:00:30 -0700216 return MAKE_HWIRQ(bank, shortcuts[ffs(stat >> SHORTCUT_SHIFT) - 1]);
217}
218
219static u32 get_next_armctrl_hwirq(void)
220{
221 u32 stat = readl_relaxed(intc.pending[0]) & BANK0_VALID_MASK;
222
223 if (stat == 0)
224 return ~0;
225 else if (stat & BANK0_HWIRQ_MASK)
226 return MAKE_HWIRQ(0, ffs(stat & BANK0_HWIRQ_MASK) - 1);
227 else if (stat & SHORTCUT1_MASK)
228 return armctrl_translate_shortcut(1, stat & SHORTCUT1_MASK);
229 else if (stat & SHORTCUT2_MASK)
230 return armctrl_translate_shortcut(2, stat & SHORTCUT2_MASK);
231 else if (stat & BANK1_HWIRQ)
232 return armctrl_translate_bank(1);
233 else if (stat & BANK2_HWIRQ)
234 return armctrl_translate_bank(2);
235 else
236 BUG();
Simon Arlott89214f02012-09-12 19:57:26 -0600237}
238
Stephen Boyd8783dd32014-03-04 16:40:30 -0800239static void __exception_irq_entry bcm2835_handle_irq(
Simon Arlott89214f02012-09-12 19:57:26 -0600240 struct pt_regs *regs)
241{
Eric Anholtde58e522015-08-06 16:00:30 -0700242 u32 hwirq;
Simon Arlott89214f02012-09-12 19:57:26 -0600243
Eric Anholtde58e522015-08-06 16:00:30 -0700244 while ((hwirq = get_next_armctrl_hwirq()) != ~0)
245 handle_IRQ(irq_linear_revmap(intc.domain, hwirq), regs);
Simon Arlott89214f02012-09-12 19:57:26 -0600246}
Axel Lin57029412013-07-05 00:31:36 +0800247
Eric Anholta493f332015-08-06 16:00:31 -0700248static void bcm2836_chained_handle_irq(unsigned int irq, struct irq_desc *desc)
249{
250 u32 hwirq;
251
252 while ((hwirq = get_next_armctrl_hwirq()) != ~0)
253 generic_handle_irq(irq_linear_revmap(intc.domain, hwirq));
254}
255
256IRQCHIP_DECLARE(bcm2835_armctrl_ic, "brcm,bcm2835-armctrl-ic",
257 bcm2835_armctrl_of_init);
258IRQCHIP_DECLARE(bcm2836_armctrl_ic, "brcm,bcm2836-armctrl-ic",
259 bcm2836_armctrl_of_init);