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1eb77c3b TS |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
4 | */ | |
5 | ||
6 | #include <linux/bitfield.h> | |
7 | #include <linux/irq.h> | |
8 | #include <linux/irqchip.h> | |
9 | #include <linux/irqchip/chained_irq.h> | |
10 | #include <linux/irqdomain.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/of.h> | |
13 | #include <linux/of_address.h> | |
14 | #include <linux/of_irq.h> | |
15 | ||
16 | /* FIC Registers */ | |
17 | #define AL_FIC_CAUSE 0x00 | |
9c426b77 | 18 | #define AL_FIC_SET_CAUSE 0x08 |
1eb77c3b TS |
19 | #define AL_FIC_MASK 0x10 |
20 | #define AL_FIC_CONTROL 0x28 | |
21 | ||
22 | #define CONTROL_TRIGGER_RISING BIT(3) | |
23 | #define CONTROL_MASK_MSI_X BIT(5) | |
24 | ||
25 | #define NR_FIC_IRQS 32 | |
26 | ||
27 | MODULE_AUTHOR("Talel Shenhar"); | |
28 | MODULE_DESCRIPTION("Amazon's Annapurna Labs Interrupt Controller Driver"); | |
29 | MODULE_LICENSE("GPL v2"); | |
30 | ||
31 | enum al_fic_state { | |
32 | AL_FIC_UNCONFIGURED = 0, | |
33 | AL_FIC_CONFIGURED_LEVEL, | |
34 | AL_FIC_CONFIGURED_RISING_EDGE, | |
35 | }; | |
36 | ||
37 | struct al_fic { | |
38 | void __iomem *base; | |
39 | struct irq_domain *domain; | |
40 | const char *name; | |
41 | unsigned int parent_irq; | |
42 | enum al_fic_state state; | |
43 | }; | |
44 | ||
45 | static void al_fic_set_trigger(struct al_fic *fic, | |
46 | struct irq_chip_generic *gc, | |
47 | enum al_fic_state new_state) | |
48 | { | |
49 | irq_flow_handler_t handler; | |
50 | u32 control = readl_relaxed(fic->base + AL_FIC_CONTROL); | |
51 | ||
52 | if (new_state == AL_FIC_CONFIGURED_LEVEL) { | |
53 | handler = handle_level_irq; | |
54 | control &= ~CONTROL_TRIGGER_RISING; | |
55 | } else { | |
56 | handler = handle_edge_irq; | |
57 | control |= CONTROL_TRIGGER_RISING; | |
58 | } | |
59 | gc->chip_types->handler = handler; | |
60 | fic->state = new_state; | |
61 | writel_relaxed(control, fic->base + AL_FIC_CONTROL); | |
62 | } | |
63 | ||
64 | static int al_fic_irq_set_type(struct irq_data *data, unsigned int flow_type) | |
65 | { | |
66 | struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data); | |
67 | struct al_fic *fic = gc->private; | |
68 | enum al_fic_state new_state; | |
69 | int ret = 0; | |
70 | ||
71 | irq_gc_lock(gc); | |
72 | ||
73 | if (((flow_type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_HIGH) && | |
74 | ((flow_type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_EDGE_RISING)) { | |
75 | pr_debug("fic doesn't support flow type %d\n", flow_type); | |
76 | ret = -EINVAL; | |
77 | goto err; | |
78 | } | |
79 | ||
80 | new_state = (flow_type & IRQ_TYPE_LEVEL_HIGH) ? | |
81 | AL_FIC_CONFIGURED_LEVEL : AL_FIC_CONFIGURED_RISING_EDGE; | |
82 | ||
83 | /* | |
84 | * A given FIC instance can be either all level or all edge triggered. | |
85 | * This is generally fixed depending on what pieces of HW it's wired up | |
86 | * to. | |
87 | * | |
88 | * We configure it based on the sensitivity of the first source | |
89 | * being setup, and reject any subsequent attempt at configuring it in a | |
90 | * different way. | |
91 | */ | |
92 | if (fic->state == AL_FIC_UNCONFIGURED) { | |
93 | al_fic_set_trigger(fic, gc, new_state); | |
94 | } else if (fic->state != new_state) { | |
95 | pr_debug("fic %s state already configured to %d\n", | |
96 | fic->name, fic->state); | |
97 | ret = -EINVAL; | |
98 | goto err; | |
99 | } | |
100 | ||
101 | err: | |
102 | irq_gc_unlock(gc); | |
103 | ||
104 | return ret; | |
105 | } | |
106 | ||
107 | static void al_fic_irq_handler(struct irq_desc *desc) | |
108 | { | |
109 | struct al_fic *fic = irq_desc_get_handler_data(desc); | |
110 | struct irq_domain *domain = fic->domain; | |
111 | struct irq_chip *irqchip = irq_desc_get_chip(desc); | |
112 | struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0); | |
113 | unsigned long pending; | |
114 | unsigned int irq; | |
115 | u32 hwirq; | |
116 | ||
117 | chained_irq_enter(irqchip, desc); | |
118 | ||
119 | pending = readl_relaxed(fic->base + AL_FIC_CAUSE); | |
120 | pending &= ~gc->mask_cache; | |
121 | ||
122 | for_each_set_bit(hwirq, &pending, NR_FIC_IRQS) { | |
123 | irq = irq_find_mapping(domain, hwirq); | |
124 | generic_handle_irq(irq); | |
125 | } | |
126 | ||
127 | chained_irq_exit(irqchip, desc); | |
128 | } | |
129 | ||
9c426b77 TS |
130 | static int al_fic_irq_retrigger(struct irq_data *data) |
131 | { | |
132 | struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data); | |
133 | struct al_fic *fic = gc->private; | |
134 | ||
135 | writel_relaxed(BIT(data->hwirq), fic->base + AL_FIC_SET_CAUSE); | |
136 | ||
137 | return 1; | |
138 | } | |
139 | ||
1eb77c3b TS |
140 | static int al_fic_register(struct device_node *node, |
141 | struct al_fic *fic) | |
142 | { | |
143 | struct irq_chip_generic *gc; | |
144 | int ret; | |
145 | ||
146 | fic->domain = irq_domain_add_linear(node, | |
147 | NR_FIC_IRQS, | |
148 | &irq_generic_chip_ops, | |
149 | fic); | |
150 | if (!fic->domain) { | |
151 | pr_err("fail to add irq domain\n"); | |
152 | return -ENOMEM; | |
153 | } | |
154 | ||
155 | ret = irq_alloc_domain_generic_chips(fic->domain, | |
156 | NR_FIC_IRQS, | |
157 | 1, fic->name, | |
158 | handle_level_irq, | |
159 | 0, 0, IRQ_GC_INIT_MASK_CACHE); | |
160 | if (ret) { | |
161 | pr_err("fail to allocate generic chip (%d)\n", ret); | |
162 | goto err_domain_remove; | |
163 | } | |
164 | ||
165 | gc = irq_get_domain_generic_chip(fic->domain, 0); | |
166 | gc->reg_base = fic->base; | |
167 | gc->chip_types->regs.mask = AL_FIC_MASK; | |
168 | gc->chip_types->regs.ack = AL_FIC_CAUSE; | |
169 | gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit; | |
170 | gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit; | |
171 | gc->chip_types->chip.irq_ack = irq_gc_ack_clr_bit; | |
172 | gc->chip_types->chip.irq_set_type = al_fic_irq_set_type; | |
9c426b77 | 173 | gc->chip_types->chip.irq_retrigger = al_fic_irq_retrigger; |
1eb77c3b TS |
174 | gc->chip_types->chip.flags = IRQCHIP_SKIP_SET_WAKE; |
175 | gc->private = fic; | |
176 | ||
177 | irq_set_chained_handler_and_data(fic->parent_irq, | |
178 | al_fic_irq_handler, | |
179 | fic); | |
180 | return 0; | |
181 | ||
182 | err_domain_remove: | |
183 | irq_domain_remove(fic->domain); | |
184 | ||
185 | return ret; | |
186 | } | |
187 | ||
188 | /* | |
189 | * al_fic_wire_init() - initialize and configure fic in wire mode | |
190 | * @of_node: optional pointer to interrupt controller's device tree node. | |
191 | * @base: mmio to fic register | |
192 | * @name: name of the fic | |
193 | * @parent_irq: interrupt of parent | |
194 | * | |
195 | * This API will configure the fic hardware to to work in wire mode. | |
196 | * In wire mode, fic hardware is generating a wire ("wired") interrupt. | |
197 | * Interrupt can be generated based on positive edge or level - configuration is | |
198 | * to be determined based on connected hardware to this fic. | |
199 | */ | |
200 | static struct al_fic *al_fic_wire_init(struct device_node *node, | |
201 | void __iomem *base, | |
202 | const char *name, | |
203 | unsigned int parent_irq) | |
204 | { | |
205 | struct al_fic *fic; | |
206 | int ret; | |
207 | u32 control = CONTROL_MASK_MSI_X; | |
208 | ||
209 | fic = kzalloc(sizeof(*fic), GFP_KERNEL); | |
210 | if (!fic) | |
211 | return ERR_PTR(-ENOMEM); | |
212 | ||
213 | fic->base = base; | |
214 | fic->parent_irq = parent_irq; | |
215 | fic->name = name; | |
216 | ||
217 | /* mask out all interrupts */ | |
218 | writel_relaxed(0xFFFFFFFF, fic->base + AL_FIC_MASK); | |
219 | ||
220 | /* clear any pending interrupt */ | |
221 | writel_relaxed(0, fic->base + AL_FIC_CAUSE); | |
222 | ||
223 | writel_relaxed(control, fic->base + AL_FIC_CONTROL); | |
224 | ||
225 | ret = al_fic_register(node, fic); | |
226 | if (ret) { | |
227 | pr_err("fail to register irqchip\n"); | |
228 | goto err_free; | |
229 | } | |
230 | ||
231 | pr_debug("%s initialized successfully in Legacy mode (parent-irq=%u)\n", | |
232 | fic->name, parent_irq); | |
233 | ||
234 | return fic; | |
235 | ||
236 | err_free: | |
237 | kfree(fic); | |
238 | return ERR_PTR(ret); | |
239 | } | |
240 | ||
241 | static int __init al_fic_init_dt(struct device_node *node, | |
242 | struct device_node *parent) | |
243 | { | |
244 | int ret; | |
245 | void __iomem *base; | |
246 | unsigned int parent_irq; | |
247 | struct al_fic *fic; | |
248 | ||
249 | if (!parent) { | |
250 | pr_err("%s: unsupported - device require a parent\n", | |
251 | node->name); | |
252 | return -EINVAL; | |
253 | } | |
254 | ||
255 | base = of_iomap(node, 0); | |
256 | if (!base) { | |
257 | pr_err("%s: fail to map memory\n", node->name); | |
258 | return -ENOMEM; | |
259 | } | |
260 | ||
261 | parent_irq = irq_of_parse_and_map(node, 0); | |
262 | if (!parent_irq) { | |
263 | pr_err("%s: fail to map irq\n", node->name); | |
264 | ret = -EINVAL; | |
265 | goto err_unmap; | |
266 | } | |
267 | ||
268 | fic = al_fic_wire_init(node, | |
269 | base, | |
270 | node->name, | |
271 | parent_irq); | |
272 | if (IS_ERR(fic)) { | |
273 | pr_err("%s: fail to initialize irqchip (%lu)\n", | |
274 | node->name, | |
275 | PTR_ERR(fic)); | |
276 | ret = PTR_ERR(fic); | |
277 | goto err_irq_dispose; | |
278 | } | |
279 | ||
280 | return 0; | |
281 | ||
282 | err_irq_dispose: | |
283 | irq_dispose_mapping(parent_irq); | |
284 | err_unmap: | |
285 | iounmap(base); | |
286 | ||
287 | return ret; | |
288 | } | |
289 | ||
290 | IRQCHIP_DECLARE(al_fic, "amazon,al-fic", al_fic_init_dt); |