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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Support for Versatile FPGA-based IRQ controllers
4 */
5#include <linux/bitops.h>
6#include <linux/irq.h>
7#include <linux/io.h>
8#include <linux/irqchip.h>
9#include <linux/irqchip/chained_irq.h>
10#include <linux/irqchip/versatile-fpga.h>
11#include <linux/irqdomain.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/of_address.h>
15#include <linux/of_irq.h>
16
17#include <asm/exception.h>
18#include <asm/mach/irq.h>
19
20#define IRQ_STATUS 0x00
21#define IRQ_RAW_STATUS 0x04
22#define IRQ_ENABLE_SET 0x08
23#define IRQ_ENABLE_CLEAR 0x0c
24#define INT_SOFT_SET 0x10
25#define INT_SOFT_CLEAR 0x14
26#define FIQ_STATUS 0x20
27#define FIQ_RAW_STATUS 0x24
28#define FIQ_ENABLE 0x28
29#define FIQ_ENABLE_SET 0x28
30#define FIQ_ENABLE_CLEAR 0x2C
31
32#define PIC_ENABLES 0x20 /* set interrupt pass through bits */
33
34/**
35 * struct fpga_irq_data - irq data container for the FPGA IRQ controller
36 * @base: memory offset in virtual memory
37 * @chip: chip container for this instance
38 * @domain: IRQ domain for this instance
39 * @valid: mask for valid IRQs on this controller
40 * @used_irqs: number of active IRQs on this controller
41 */
42struct fpga_irq_data {
43 void __iomem *base;
44 struct irq_chip chip;
45 u32 valid;
46 struct irq_domain *domain;
47 u8 used_irqs;
48};
49
50/* we cannot allocate memory when the controllers are initially registered */
51static struct fpga_irq_data fpga_irq_devices[CONFIG_VERSATILE_FPGA_IRQ_NR];
52static int fpga_irq_id;
53
54static void fpga_irq_mask(struct irq_data *d)
55{
56 struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
57 u32 mask = 1 << d->hwirq;
58
59 writel(mask, f->base + IRQ_ENABLE_CLEAR);
60}
61
62static void fpga_irq_unmask(struct irq_data *d)
63{
64 struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
65 u32 mask = 1 << d->hwirq;
66
67 writel(mask, f->base + IRQ_ENABLE_SET);
68}
69
70static void fpga_irq_handle(struct irq_desc *desc)
71{
72 struct irq_chip *chip = irq_desc_get_chip(desc);
73 struct fpga_irq_data *f = irq_desc_get_handler_data(desc);
74 u32 status;
75
76 chained_irq_enter(chip, desc);
77
78 status = readl(f->base + IRQ_STATUS);
79 if (status == 0) {
80 do_bad_IRQ(desc);
81 goto out;
82 }
83
84 do {
85 unsigned int irq = ffs(status) - 1;
86
87 status &= ~(1 << irq);
88 generic_handle_irq(irq_find_mapping(f->domain, irq));
89 } while (status);
90
91out:
92 chained_irq_exit(chip, desc);
93}
94
95/*
96 * Handle each interrupt in a single FPGA IRQ controller. Returns non-zero
97 * if we've handled at least one interrupt. This does a single read of the
98 * status register and handles all interrupts in order from LSB first.
99 */
100static int handle_one_fpga(struct fpga_irq_data *f, struct pt_regs *regs)
101{
102 int handled = 0;
103 int irq;
104 u32 status;
105
106 while ((status = readl(f->base + IRQ_STATUS))) {
107 irq = ffs(status) - 1;
108 handle_domain_irq(f->domain, irq, regs);
109 handled = 1;
110 }
111
112 return handled;
113}
114
115/*
116 * Keep iterating over all registered FPGA IRQ controllers until there are
117 * no pending interrupts.
118 */
119asmlinkage void __exception_irq_entry fpga_handle_irq(struct pt_regs *regs)
120{
121 int i, handled;
122
123 do {
124 for (i = 0, handled = 0; i < fpga_irq_id; ++i)
125 handled |= handle_one_fpga(&fpga_irq_devices[i], regs);
126 } while (handled);
127}
128
129static int fpga_irqdomain_map(struct irq_domain *d, unsigned int irq,
130 irq_hw_number_t hwirq)
131{
132 struct fpga_irq_data *f = d->host_data;
133
134 /* Skip invalid IRQs, only register handlers for the real ones */
135 if (!(f->valid & BIT(hwirq)))
136 return -EPERM;
137 irq_set_chip_data(irq, f);
138 irq_set_chip_and_handler(irq, &f->chip,
139 handle_level_irq);
140 irq_set_probe(irq);
141 return 0;
142}
143
144static const struct irq_domain_ops fpga_irqdomain_ops = {
145 .map = fpga_irqdomain_map,
146 .xlate = irq_domain_xlate_onetwocell,
147};
148
149void __init fpga_irq_init(void __iomem *base, const char *name, int irq_start,
150 int parent_irq, u32 valid, struct device_node *node)
151{
152 struct fpga_irq_data *f;
153 int i;
154
155 if (fpga_irq_id >= ARRAY_SIZE(fpga_irq_devices)) {
156 pr_err("%s: too few FPGA IRQ controllers, increase CONFIG_VERSATILE_FPGA_IRQ_NR\n", __func__);
157 return;
158 }
159 f = &fpga_irq_devices[fpga_irq_id];
160 f->base = base;
161 f->chip.name = name;
162 f->chip.irq_ack = fpga_irq_mask;
163 f->chip.irq_mask = fpga_irq_mask;
164 f->chip.irq_unmask = fpga_irq_unmask;
165 f->valid = valid;
166
167 if (parent_irq != -1) {
168 irq_set_chained_handler_and_data(parent_irq, fpga_irq_handle,
169 f);
170 }
171
172 /* This will also allocate irq descriptors */
173 f->domain = irq_domain_add_simple(node, fls(valid), irq_start,
174 &fpga_irqdomain_ops, f);
175
176 /* This will allocate all valid descriptors in the linear case */
177 for (i = 0; i < fls(valid); i++)
178 if (valid & BIT(i)) {
179 if (!irq_start)
180 irq_create_mapping(f->domain, i);
181 f->used_irqs++;
182 }
183
184 pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs",
185 fpga_irq_id, name, base, f->used_irqs);
186 if (parent_irq != -1)
187 pr_cont(", parent IRQ: %d\n", parent_irq);
188 else
189 pr_cont("\n");
190
191 fpga_irq_id++;
192}
193
194#ifdef CONFIG_OF
195int __init fpga_irq_of_init(struct device_node *node,
196 struct device_node *parent)
197{
198 void __iomem *base;
199 u32 clear_mask;
200 u32 valid_mask;
201 int parent_irq;
202
203 if (WARN_ON(!node))
204 return -ENODEV;
205
206 base = of_iomap(node, 0);
207 WARN(!base, "unable to map fpga irq registers\n");
208
209 if (of_property_read_u32(node, "clear-mask", &clear_mask))
210 clear_mask = 0;
211
212 if (of_property_read_u32(node, "valid-mask", &valid_mask))
213 valid_mask = 0;
214
215 writel(clear_mask, base + IRQ_ENABLE_CLEAR);
216 writel(clear_mask, base + FIQ_ENABLE_CLEAR);
217
218 /* Some chips are cascaded from a parent IRQ */
219 parent_irq = irq_of_parse_and_map(node, 0);
220 if (!parent_irq) {
221 set_handle_irq(fpga_handle_irq);
222 parent_irq = -1;
223 }
224
225 fpga_irq_init(base, node->name, 0, parent_irq, valid_mask, node);
226
227 /*
228 * On Versatile AB/PB, some secondary interrupts have a direct
229 * pass-thru to the primary controller for IRQs 20 and 22-31 which need
230 * to be enabled. See section 3.10 of the Versatile AB user guide.
231 */
232 if (of_device_is_compatible(node, "arm,versatile-sic"))
233 writel(0xffd00000, base + PIC_ENABLES);
234
235 return 0;
236}
237IRQCHIP_DECLARE(arm_fpga, "arm,versatile-fpga-irq", fpga_irq_of_init);
238IRQCHIP_DECLARE(arm_fpga_sic, "arm,versatile-sic", fpga_irq_of_init);
239IRQCHIP_DECLARE(ox810se_rps, "oxsemi,ox810se-rps-irq", fpga_irq_of_init);
240#endif
1/*
2 * Support for Versatile FPGA-based IRQ controllers
3 */
4#include <linux/bitops.h>
5#include <linux/irq.h>
6#include <linux/io.h>
7#include <linux/irqchip/versatile-fpga.h>
8#include <linux/irqdomain.h>
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/of_address.h>
12#include <linux/of_irq.h>
13
14#include <asm/exception.h>
15#include <asm/mach/irq.h>
16
17#define IRQ_STATUS 0x00
18#define IRQ_RAW_STATUS 0x04
19#define IRQ_ENABLE_SET 0x08
20#define IRQ_ENABLE_CLEAR 0x0c
21#define INT_SOFT_SET 0x10
22#define INT_SOFT_CLEAR 0x14
23#define FIQ_STATUS 0x20
24#define FIQ_RAW_STATUS 0x24
25#define FIQ_ENABLE 0x28
26#define FIQ_ENABLE_SET 0x28
27#define FIQ_ENABLE_CLEAR 0x2C
28
29/**
30 * struct fpga_irq_data - irq data container for the FPGA IRQ controller
31 * @base: memory offset in virtual memory
32 * @chip: chip container for this instance
33 * @domain: IRQ domain for this instance
34 * @valid: mask for valid IRQs on this controller
35 * @used_irqs: number of active IRQs on this controller
36 */
37struct fpga_irq_data {
38 void __iomem *base;
39 struct irq_chip chip;
40 u32 valid;
41 struct irq_domain *domain;
42 u8 used_irqs;
43};
44
45/* we cannot allocate memory when the controllers are initially registered */
46static struct fpga_irq_data fpga_irq_devices[CONFIG_VERSATILE_FPGA_IRQ_NR];
47static int fpga_irq_id;
48
49static void fpga_irq_mask(struct irq_data *d)
50{
51 struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
52 u32 mask = 1 << d->hwirq;
53
54 writel(mask, f->base + IRQ_ENABLE_CLEAR);
55}
56
57static void fpga_irq_unmask(struct irq_data *d)
58{
59 struct fpga_irq_data *f = irq_data_get_irq_chip_data(d);
60 u32 mask = 1 << d->hwirq;
61
62 writel(mask, f->base + IRQ_ENABLE_SET);
63}
64
65static void fpga_irq_handle(unsigned int irq, struct irq_desc *desc)
66{
67 struct fpga_irq_data *f = irq_desc_get_handler_data(desc);
68 u32 status = readl(f->base + IRQ_STATUS);
69
70 if (status == 0) {
71 do_bad_IRQ(irq, desc);
72 return;
73 }
74
75 do {
76 irq = ffs(status) - 1;
77 status &= ~(1 << irq);
78 generic_handle_irq(irq_find_mapping(f->domain, irq));
79 } while (status);
80}
81
82/*
83 * Handle each interrupt in a single FPGA IRQ controller. Returns non-zero
84 * if we've handled at least one interrupt. This does a single read of the
85 * status register and handles all interrupts in order from LSB first.
86 */
87static int handle_one_fpga(struct fpga_irq_data *f, struct pt_regs *regs)
88{
89 int handled = 0;
90 int irq;
91 u32 status;
92
93 while ((status = readl(f->base + IRQ_STATUS))) {
94 irq = ffs(status) - 1;
95 handle_IRQ(irq_find_mapping(f->domain, irq), regs);
96 handled = 1;
97 }
98
99 return handled;
100}
101
102/*
103 * Keep iterating over all registered FPGA IRQ controllers until there are
104 * no pending interrupts.
105 */
106asmlinkage void __exception_irq_entry fpga_handle_irq(struct pt_regs *regs)
107{
108 int i, handled;
109
110 do {
111 for (i = 0, handled = 0; i < fpga_irq_id; ++i)
112 handled |= handle_one_fpga(&fpga_irq_devices[i], regs);
113 } while (handled);
114}
115
116static int fpga_irqdomain_map(struct irq_domain *d, unsigned int irq,
117 irq_hw_number_t hwirq)
118{
119 struct fpga_irq_data *f = d->host_data;
120
121 /* Skip invalid IRQs, only register handlers for the real ones */
122 if (!(f->valid & BIT(hwirq)))
123 return -EPERM;
124 irq_set_chip_data(irq, f);
125 irq_set_chip_and_handler(irq, &f->chip,
126 handle_level_irq);
127 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
128 return 0;
129}
130
131static struct irq_domain_ops fpga_irqdomain_ops = {
132 .map = fpga_irqdomain_map,
133 .xlate = irq_domain_xlate_onetwocell,
134};
135
136void __init fpga_irq_init(void __iomem *base, const char *name, int irq_start,
137 int parent_irq, u32 valid, struct device_node *node)
138{
139 struct fpga_irq_data *f;
140 int i;
141
142 if (fpga_irq_id >= ARRAY_SIZE(fpga_irq_devices)) {
143 pr_err("%s: too few FPGA IRQ controllers, increase CONFIG_VERSATILE_FPGA_IRQ_NR\n", __func__);
144 return;
145 }
146 f = &fpga_irq_devices[fpga_irq_id];
147 f->base = base;
148 f->chip.name = name;
149 f->chip.irq_ack = fpga_irq_mask;
150 f->chip.irq_mask = fpga_irq_mask;
151 f->chip.irq_unmask = fpga_irq_unmask;
152 f->valid = valid;
153
154 if (parent_irq != -1) {
155 irq_set_handler_data(parent_irq, f);
156 irq_set_chained_handler(parent_irq, fpga_irq_handle);
157 }
158
159 /* This will also allocate irq descriptors */
160 f->domain = irq_domain_add_simple(node, fls(valid), irq_start,
161 &fpga_irqdomain_ops, f);
162
163 /* This will allocate all valid descriptors in the linear case */
164 for (i = 0; i < fls(valid); i++)
165 if (valid & BIT(i)) {
166 if (!irq_start)
167 irq_create_mapping(f->domain, i);
168 f->used_irqs++;
169 }
170
171 pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs",
172 fpga_irq_id, name, base, f->used_irqs);
173 if (parent_irq != -1)
174 pr_cont(", parent IRQ: %d\n", parent_irq);
175 else
176 pr_cont("\n");
177
178 fpga_irq_id++;
179}
180
181#ifdef CONFIG_OF
182int __init fpga_irq_of_init(struct device_node *node,
183 struct device_node *parent)
184{
185 void __iomem *base;
186 u32 clear_mask;
187 u32 valid_mask;
188 int parent_irq;
189
190 if (WARN_ON(!node))
191 return -ENODEV;
192
193 base = of_iomap(node, 0);
194 WARN(!base, "unable to map fpga irq registers\n");
195
196 if (of_property_read_u32(node, "clear-mask", &clear_mask))
197 clear_mask = 0;
198
199 if (of_property_read_u32(node, "valid-mask", &valid_mask))
200 valid_mask = 0;
201
202 /* Some chips are cascaded from a parent IRQ */
203 parent_irq = irq_of_parse_and_map(node, 0);
204 if (!parent_irq)
205 parent_irq = -1;
206
207 fpga_irq_init(base, node->name, 0, parent_irq, valid_mask, node);
208
209 writel(clear_mask, base + IRQ_ENABLE_CLEAR);
210 writel(clear_mask, base + FIQ_ENABLE_CLEAR);
211
212 return 0;
213}
214#endif