Commit | Line | Data |
---|---|---|
c41b16f8 RK |
1 | /* |
2 | * Support for Versatile FPGA-based IRQ controllers | |
3 | */ | |
3a6ca8c5 | 4 | #include <linux/bitops.h> |
c41b16f8 RK |
5 | #include <linux/irq.h> |
6 | #include <linux/io.h> | |
41a83e06 | 7 | #include <linux/irqchip.h> |
2389d501 | 8 | #include <linux/irqchip/versatile-fpga.h> |
3108e6ab LW |
9 | #include <linux/irqdomain.h> |
10 | #include <linux/module.h> | |
9bc15031 LW |
11 | #include <linux/of.h> |
12 | #include <linux/of_address.h> | |
bdd272cb | 13 | #include <linux/of_irq.h> |
c41b16f8 | 14 | |
3108e6ab | 15 | #include <asm/exception.h> |
c41b16f8 | 16 | #include <asm/mach/irq.h> |
c41b16f8 RK |
17 | |
18 | #define IRQ_STATUS 0x00 | |
19 | #define IRQ_RAW_STATUS 0x04 | |
20 | #define IRQ_ENABLE_SET 0x08 | |
21 | #define IRQ_ENABLE_CLEAR 0x0c | |
9bc15031 LW |
22 | #define INT_SOFT_SET 0x10 |
23 | #define INT_SOFT_CLEAR 0x14 | |
24 | #define FIQ_STATUS 0x20 | |
25 | #define FIQ_RAW_STATUS 0x24 | |
26 | #define FIQ_ENABLE 0x28 | |
27 | #define FIQ_ENABLE_SET 0x28 | |
28 | #define FIQ_ENABLE_CLEAR 0x2C | |
c41b16f8 | 29 | |
59318461 RH |
30 | #define PIC_ENABLES 0x20 /* set interrupt pass through bits */ |
31 | ||
3108e6ab LW |
32 | /** |
33 | * struct fpga_irq_data - irq data container for the FPGA IRQ controller | |
34 | * @base: memory offset in virtual memory | |
3108e6ab LW |
35 | * @chip: chip container for this instance |
36 | * @domain: IRQ domain for this instance | |
37 | * @valid: mask for valid IRQs on this controller | |
38 | * @used_irqs: number of active IRQs on this controller | |
39 | */ | |
40 | struct fpga_irq_data { | |
41 | void __iomem *base; | |
3108e6ab LW |
42 | struct irq_chip chip; |
43 | u32 valid; | |
44 | struct irq_domain *domain; | |
45 | u8 used_irqs; | |
46 | }; | |
47 | ||
48 | /* we cannot allocate memory when the controllers are initially registered */ | |
2389d501 | 49 | static struct fpga_irq_data fpga_irq_devices[CONFIG_VERSATILE_FPGA_IRQ_NR]; |
3108e6ab LW |
50 | static int fpga_irq_id; |
51 | ||
c41b16f8 RK |
52 | static void fpga_irq_mask(struct irq_data *d) |
53 | { | |
54 | struct fpga_irq_data *f = irq_data_get_irq_chip_data(d); | |
3108e6ab | 55 | u32 mask = 1 << d->hwirq; |
c41b16f8 RK |
56 | |
57 | writel(mask, f->base + IRQ_ENABLE_CLEAR); | |
58 | } | |
59 | ||
60 | static void fpga_irq_unmask(struct irq_data *d) | |
61 | { | |
62 | struct fpga_irq_data *f = irq_data_get_irq_chip_data(d); | |
3108e6ab | 63 | u32 mask = 1 << d->hwirq; |
c41b16f8 RK |
64 | |
65 | writel(mask, f->base + IRQ_ENABLE_SET); | |
66 | } | |
67 | ||
68 | static void fpga_irq_handle(unsigned int irq, struct irq_desc *desc) | |
69 | { | |
6845664a | 70 | struct fpga_irq_data *f = irq_desc_get_handler_data(desc); |
c41b16f8 RK |
71 | u32 status = readl(f->base + IRQ_STATUS); |
72 | ||
73 | if (status == 0) { | |
74 | do_bad_IRQ(irq, desc); | |
75 | return; | |
76 | } | |
77 | ||
78 | do { | |
79 | irq = ffs(status) - 1; | |
80 | status &= ~(1 << irq); | |
3108e6ab | 81 | generic_handle_irq(irq_find_mapping(f->domain, irq)); |
c41b16f8 RK |
82 | } while (status); |
83 | } | |
84 | ||
3108e6ab LW |
85 | /* |
86 | * Handle each interrupt in a single FPGA IRQ controller. Returns non-zero | |
87 | * if we've handled at least one interrupt. This does a single read of the | |
88 | * status register and handles all interrupts in order from LSB first. | |
89 | */ | |
90 | static int handle_one_fpga(struct fpga_irq_data *f, struct pt_regs *regs) | |
91 | { | |
92 | int handled = 0; | |
93 | int irq; | |
94 | u32 status; | |
95 | ||
96 | while ((status = readl(f->base + IRQ_STATUS))) { | |
97 | irq = ffs(status) - 1; | |
84bc7399 | 98 | handle_domain_irq(f->domain, irq, regs); |
3108e6ab LW |
99 | handled = 1; |
100 | } | |
101 | ||
102 | return handled; | |
103 | } | |
104 | ||
105 | /* | |
106 | * Keep iterating over all registered FPGA IRQ controllers until there are | |
107 | * no pending interrupts. | |
108 | */ | |
109 | asmlinkage void __exception_irq_entry fpga_handle_irq(struct pt_regs *regs) | |
c41b16f8 | 110 | { |
3108e6ab | 111 | int i, handled; |
c41b16f8 | 112 | |
3108e6ab LW |
113 | do { |
114 | for (i = 0, handled = 0; i < fpga_irq_id; ++i) | |
115 | handled |= handle_one_fpga(&fpga_irq_devices[i], regs); | |
116 | } while (handled); | |
117 | } | |
118 | ||
119 | static int fpga_irqdomain_map(struct irq_domain *d, unsigned int irq, | |
120 | irq_hw_number_t hwirq) | |
121 | { | |
122 | struct fpga_irq_data *f = d->host_data; | |
123 | ||
124 | /* Skip invalid IRQs, only register handlers for the real ones */ | |
3a6ca8c5 | 125 | if (!(f->valid & BIT(hwirq))) |
d94ea3f6 | 126 | return -EPERM; |
3108e6ab LW |
127 | irq_set_chip_data(irq, f); |
128 | irq_set_chip_and_handler(irq, &f->chip, | |
129 | handle_level_irq); | |
130 | set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); | |
3108e6ab LW |
131 | return 0; |
132 | } | |
133 | ||
96009736 | 134 | static const struct irq_domain_ops fpga_irqdomain_ops = { |
3108e6ab LW |
135 | .map = fpga_irqdomain_map, |
136 | .xlate = irq_domain_xlate_onetwocell, | |
137 | }; | |
138 | ||
3a6ca8c5 LW |
139 | void __init fpga_irq_init(void __iomem *base, const char *name, int irq_start, |
140 | int parent_irq, u32 valid, struct device_node *node) | |
141 | { | |
3108e6ab | 142 | struct fpga_irq_data *f; |
3a6ca8c5 | 143 | int i; |
3108e6ab LW |
144 | |
145 | if (fpga_irq_id >= ARRAY_SIZE(fpga_irq_devices)) { | |
e6423f8b | 146 | pr_err("%s: too few FPGA IRQ controllers, increase CONFIG_VERSATILE_FPGA_IRQ_NR\n", __func__); |
3a6ca8c5 | 147 | return; |
3108e6ab | 148 | } |
3108e6ab LW |
149 | f = &fpga_irq_devices[fpga_irq_id]; |
150 | f->base = base; | |
3108e6ab | 151 | f->chip.name = name; |
c41b16f8 RK |
152 | f->chip.irq_ack = fpga_irq_mask; |
153 | f->chip.irq_mask = fpga_irq_mask; | |
154 | f->chip.irq_unmask = fpga_irq_unmask; | |
3108e6ab | 155 | f->valid = valid; |
c41b16f8 RK |
156 | |
157 | if (parent_irq != -1) { | |
6845664a TG |
158 | irq_set_handler_data(parent_irq, f); |
159 | irq_set_chained_handler(parent_irq, fpga_irq_handle); | |
c41b16f8 RK |
160 | } |
161 | ||
3a6ca8c5 LW |
162 | /* This will also allocate irq descriptors */ |
163 | f->domain = irq_domain_add_simple(node, fls(valid), irq_start, | |
3108e6ab | 164 | &fpga_irqdomain_ops, f); |
3a6ca8c5 LW |
165 | |
166 | /* This will allocate all valid descriptors in the linear case */ | |
167 | for (i = 0; i < fls(valid); i++) | |
168 | if (valid & BIT(i)) { | |
169 | if (!irq_start) | |
170 | irq_create_mapping(f->domain, i); | |
171 | f->used_irqs++; | |
172 | } | |
173 | ||
bdd272cb | 174 | pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs", |
3108e6ab | 175 | fpga_irq_id, name, base, f->used_irqs); |
bdd272cb LW |
176 | if (parent_irq != -1) |
177 | pr_cont(", parent IRQ: %d\n", parent_irq); | |
178 | else | |
179 | pr_cont("\n"); | |
3a6ca8c5 LW |
180 | |
181 | fpga_irq_id++; | |
9bc15031 | 182 | } |
c41b16f8 | 183 | |
9bc15031 LW |
184 | #ifdef CONFIG_OF |
185 | int __init fpga_irq_of_init(struct device_node *node, | |
186 | struct device_node *parent) | |
187 | { | |
9bc15031 LW |
188 | void __iomem *base; |
189 | u32 clear_mask; | |
190 | u32 valid_mask; | |
bdd272cb | 191 | int parent_irq; |
9bc15031 LW |
192 | |
193 | if (WARN_ON(!node)) | |
194 | return -ENODEV; | |
195 | ||
196 | base = of_iomap(node, 0); | |
197 | WARN(!base, "unable to map fpga irq registers\n"); | |
198 | ||
199 | if (of_property_read_u32(node, "clear-mask", &clear_mask)) | |
200 | clear_mask = 0; | |
201 | ||
202 | if (of_property_read_u32(node, "valid-mask", &valid_mask)) | |
203 | valid_mask = 0; | |
204 | ||
bdd272cb LW |
205 | /* Some chips are cascaded from a parent IRQ */ |
206 | parent_irq = irq_of_parse_and_map(node, 0); | |
2920bc9a RH |
207 | if (!parent_irq) { |
208 | set_handle_irq(fpga_handle_irq); | |
bdd272cb | 209 | parent_irq = -1; |
2920bc9a | 210 | } |
bdd272cb LW |
211 | |
212 | fpga_irq_init(base, node->name, 0, parent_irq, valid_mask, node); | |
9bc15031 LW |
213 | |
214 | writel(clear_mask, base + IRQ_ENABLE_CLEAR); | |
215 | writel(clear_mask, base + FIQ_ENABLE_CLEAR); | |
216 | ||
59318461 RH |
217 | /* |
218 | * On Versatile AB/PB, some secondary interrupts have a direct | |
219 | * pass-thru to the primary controller for IRQs 20 and 22-31 which need | |
220 | * to be enabled. See section 3.10 of the Versatile AB user guide. | |
221 | */ | |
222 | if (of_device_is_compatible(node, "arm,versatile-sic")) | |
223 | writel(0xffd00000, base + PIC_ENABLES); | |
224 | ||
9bc15031 | 225 | return 0; |
c41b16f8 | 226 | } |
2920bc9a | 227 | IRQCHIP_DECLARE(arm_fpga, "arm,versatile-fpga-irq", fpga_irq_of_init); |
59318461 | 228 | IRQCHIP_DECLARE(arm_fpga_sic, "arm,versatile-sic", fpga_irq_of_init); |
9bc15031 | 229 | #endif |