1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2017-2018 Bartosz Golaszewski <brgl@bgdev.pl>
4 * Copyright (C) 2020 Bartosz Golaszewski <bgolaszewski@baylibre.com>
5 */
6
7 #include <linux/irq.h>
8 #include <linux/irq_sim.h>
9 #include <linux/irq_work.h>
10 #include <linux/interrupt.h>
11 #include <linux/slab.h>
12
13 struct irq_sim_work_ctx {
14 struct irq_work work;
15 int irq_base;
16 unsigned int irq_count;
17 unsigned long *pending;
18 struct irq_domain *domain;
19 };
20
21 struct irq_sim_irq_ctx {
22 int irqnum;
23 bool enabled;
24 struct irq_sim_work_ctx *work_ctx;
25 };
26
irq_sim_irqmask(struct irq_data * data)27 static void irq_sim_irqmask(struct irq_data *data)
28 {
29 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
30
31 irq_ctx->enabled = false;
32 }
33
irq_sim_irqunmask(struct irq_data * data)34 static void irq_sim_irqunmask(struct irq_data *data)
35 {
36 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
37
38 irq_ctx->enabled = true;
39 }
40
irq_sim_set_type(struct irq_data * data,unsigned int type)41 static int irq_sim_set_type(struct irq_data *data, unsigned int type)
42 {
43 /* We only support rising and falling edge trigger types. */
44 if (type & ~IRQ_TYPE_EDGE_BOTH)
45 return -EINVAL;
46
47 irqd_set_trigger_type(data, type);
48
49 return 0;
50 }
51
irq_sim_get_irqchip_state(struct irq_data * data,enum irqchip_irq_state which,bool * state)52 static int irq_sim_get_irqchip_state(struct irq_data *data,
53 enum irqchip_irq_state which, bool *state)
54 {
55 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
56 irq_hw_number_t hwirq = irqd_to_hwirq(data);
57
58 switch (which) {
59 case IRQCHIP_STATE_PENDING:
60 if (irq_ctx->enabled)
61 *state = test_bit(hwirq, irq_ctx->work_ctx->pending);
62 break;
63 default:
64 return -EINVAL;
65 }
66
67 return 0;
68 }
69
irq_sim_set_irqchip_state(struct irq_data * data,enum irqchip_irq_state which,bool state)70 static int irq_sim_set_irqchip_state(struct irq_data *data,
71 enum irqchip_irq_state which, bool state)
72 {
73 struct irq_sim_irq_ctx *irq_ctx = irq_data_get_irq_chip_data(data);
74 irq_hw_number_t hwirq = irqd_to_hwirq(data);
75
76 switch (which) {
77 case IRQCHIP_STATE_PENDING:
78 if (irq_ctx->enabled) {
79 assign_bit(hwirq, irq_ctx->work_ctx->pending, state);
80 if (state)
81 irq_work_queue(&irq_ctx->work_ctx->work);
82 }
83 break;
84 default:
85 return -EINVAL;
86 }
87
88 return 0;
89 }
90
91 static struct irq_chip irq_sim_irqchip = {
92 .name = "irq_sim",
93 .irq_mask = irq_sim_irqmask,
94 .irq_unmask = irq_sim_irqunmask,
95 .irq_set_type = irq_sim_set_type,
96 .irq_get_irqchip_state = irq_sim_get_irqchip_state,
97 .irq_set_irqchip_state = irq_sim_set_irqchip_state,
98 };
99
irq_sim_handle_irq(struct irq_work * work)100 static void irq_sim_handle_irq(struct irq_work *work)
101 {
102 struct irq_sim_work_ctx *work_ctx;
103 unsigned int offset = 0;
104 int irqnum;
105
106 work_ctx = container_of(work, struct irq_sim_work_ctx, work);
107
108 while (!bitmap_empty(work_ctx->pending, work_ctx->irq_count)) {
109 offset = find_next_bit(work_ctx->pending,
110 work_ctx->irq_count, offset);
111 clear_bit(offset, work_ctx->pending);
112 irqnum = irq_find_mapping(work_ctx->domain, offset);
113 handle_simple_irq(irq_to_desc(irqnum));
114 }
115 }
116
irq_sim_domain_map(struct irq_domain * domain,unsigned int virq,irq_hw_number_t hw)117 static int irq_sim_domain_map(struct irq_domain *domain,
118 unsigned int virq, irq_hw_number_t hw)
119 {
120 struct irq_sim_work_ctx *work_ctx = domain->host_data;
121 struct irq_sim_irq_ctx *irq_ctx;
122
123 irq_ctx = kzalloc(sizeof(*irq_ctx), GFP_KERNEL);
124 if (!irq_ctx)
125 return -ENOMEM;
126
127 irq_set_chip(virq, &irq_sim_irqchip);
128 irq_set_chip_data(virq, irq_ctx);
129 irq_set_handler(virq, handle_simple_irq);
130 irq_modify_status(virq, IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
131 irq_ctx->work_ctx = work_ctx;
132
133 return 0;
134 }
135
irq_sim_domain_unmap(struct irq_domain * domain,unsigned int virq)136 static void irq_sim_domain_unmap(struct irq_domain *domain, unsigned int virq)
137 {
138 struct irq_sim_irq_ctx *irq_ctx;
139 struct irq_data *irqd;
140
141 irqd = irq_domain_get_irq_data(domain, virq);
142 irq_ctx = irq_data_get_irq_chip_data(irqd);
143
144 irq_set_handler(virq, NULL);
145 irq_domain_reset_irq_data(irqd);
146 kfree(irq_ctx);
147 }
148
149 static const struct irq_domain_ops irq_sim_domain_ops = {
150 .map = irq_sim_domain_map,
151 .unmap = irq_sim_domain_unmap,
152 };
153
154 /**
155 * irq_domain_create_sim - Create a new interrupt simulator irq_domain and
156 * allocate a range of dummy interrupts.
157 *
158 * @fwnode: struct fwnode_handle to be associated with this domain.
159 * @num_irqs: Number of interrupts to allocate.
160 *
161 * On success: return a new irq_domain object.
162 * On failure: a negative errno wrapped with ERR_PTR().
163 */
irq_domain_create_sim(struct fwnode_handle * fwnode,unsigned int num_irqs)164 struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
165 unsigned int num_irqs)
166 {
167 struct irq_sim_work_ctx *work_ctx;
168
169 work_ctx = kmalloc(sizeof(*work_ctx), GFP_KERNEL);
170 if (!work_ctx)
171 goto err_out;
172
173 work_ctx->pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
174 if (!work_ctx->pending)
175 goto err_free_work_ctx;
176
177 work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs,
178 &irq_sim_domain_ops,
179 work_ctx);
180 if (!work_ctx->domain)
181 goto err_free_bitmap;
182
183 work_ctx->irq_count = num_irqs;
184 work_ctx->work = IRQ_WORK_INIT_HARD(irq_sim_handle_irq);
185
186 return work_ctx->domain;
187
188 err_free_bitmap:
189 bitmap_free(work_ctx->pending);
190 err_free_work_ctx:
191 kfree(work_ctx);
192 err_out:
193 return ERR_PTR(-ENOMEM);
194 }
195 EXPORT_SYMBOL_GPL(irq_domain_create_sim);
196
197 /**
198 * irq_domain_remove_sim - Deinitialize the interrupt simulator domain: free
199 * the interrupt descriptors and allocated memory.
200 *
201 * @domain: The interrupt simulator domain to tear down.
202 */
irq_domain_remove_sim(struct irq_domain * domain)203 void irq_domain_remove_sim(struct irq_domain *domain)
204 {
205 struct irq_sim_work_ctx *work_ctx = domain->host_data;
206
207 irq_work_sync(&work_ctx->work);
208 bitmap_free(work_ctx->pending);
209 kfree(work_ctx);
210
211 irq_domain_remove(domain);
212 }
213 EXPORT_SYMBOL_GPL(irq_domain_remove_sim);
214
devm_irq_domain_remove_sim(void * data)215 static void devm_irq_domain_remove_sim(void *data)
216 {
217 struct irq_domain *domain = data;
218
219 irq_domain_remove_sim(domain);
220 }
221
222 /**
223 * devm_irq_domain_create_sim - Create a new interrupt simulator for
224 * a managed device.
225 *
226 * @dev: Device to initialize the simulator object for.
227 * @fwnode: struct fwnode_handle to be associated with this domain.
228 * @num_irqs: Number of interrupts to allocate
229 *
230 * On success: return a new irq_domain object.
231 * On failure: a negative errno wrapped with ERR_PTR().
232 */
devm_irq_domain_create_sim(struct device * dev,struct fwnode_handle * fwnode,unsigned int num_irqs)233 struct irq_domain *devm_irq_domain_create_sim(struct device *dev,
234 struct fwnode_handle *fwnode,
235 unsigned int num_irqs)
236 {
237 struct irq_domain *domain;
238 int ret;
239
240 domain = irq_domain_create_sim(fwnode, num_irqs);
241 if (IS_ERR(domain))
242 return domain;
243
244 ret = devm_add_action_or_reset(dev, devm_irq_domain_remove_sim, domain);
245 if (ret)
246 return ERR_PTR(ret);
247
248 return domain;
249 }
250 EXPORT_SYMBOL_GPL(devm_irq_domain_create_sim);
251