xref: /linux/drivers/irqchip/irq-mvebu-gicp.c (revision 0d6ccfe6b319d56da63b7d7cfbcecd92780a680d)
1 /*
2  * Copyright (C) 2017 Marvell
3  *
4  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
5  *
6  * This file is licensed under the terms of the GNU General Public
7  * License version 2. This program is licensed "as is" without any
8  * warranty of any kind, whether express or implied.
9  */
10 
11 #include <linux/io.h>
12 #include <linux/irq.h>
13 #include <linux/irqdomain.h>
14 #include <linux/msi.h>
15 #include <linux/of.h>
16 #include <linux/of_irq.h>
17 #include <linux/of_platform.h>
18 #include <linux/platform_device.h>
19 
20 #include "irq-msi-lib.h"
21 
22 #include <dt-bindings/interrupt-controller/arm-gic.h>
23 
24 #define GICP_SETSPI_NSR_OFFSET	0x0
25 #define GICP_CLRSPI_NSR_OFFSET	0x8
26 
27 struct mvebu_gicp_spi_range {
28 	unsigned int start;
29 	unsigned int count;
30 };
31 
32 struct mvebu_gicp {
33 	struct mvebu_gicp_spi_range *spi_ranges;
34 	unsigned int spi_ranges_cnt;
35 	unsigned int spi_cnt;
36 	unsigned long *spi_bitmap;
37 	spinlock_t spi_lock;
38 	struct resource *res;
39 	struct device *dev;
40 };
41 
42 static int gicp_idx_to_spi(struct mvebu_gicp *gicp, int idx)
43 {
44 	int i;
45 
46 	for (i = 0; i < gicp->spi_ranges_cnt; i++) {
47 		struct mvebu_gicp_spi_range *r = &gicp->spi_ranges[i];
48 
49 		if (idx < r->count)
50 			return r->start + idx;
51 
52 		idx -= r->count;
53 	}
54 
55 	return -EINVAL;
56 }
57 
58 static void gicp_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
59 {
60 	struct mvebu_gicp *gicp = data->chip_data;
61 	phys_addr_t setspi = gicp->res->start + GICP_SETSPI_NSR_OFFSET;
62 	phys_addr_t clrspi = gicp->res->start + GICP_CLRSPI_NSR_OFFSET;
63 
64 	msg[0].data = data->hwirq;
65 	msg[0].address_lo = lower_32_bits(setspi);
66 	msg[0].address_hi = upper_32_bits(setspi);
67 	msg[1].data = data->hwirq;
68 	msg[1].address_lo = lower_32_bits(clrspi);
69 	msg[1].address_hi = upper_32_bits(clrspi);
70 }
71 
72 static struct irq_chip gicp_irq_chip = {
73 	.name			= "GICP",
74 	.irq_mask		= irq_chip_mask_parent,
75 	.irq_unmask		= irq_chip_unmask_parent,
76 	.irq_eoi		= irq_chip_eoi_parent,
77 	.irq_set_affinity	= irq_chip_set_affinity_parent,
78 	.irq_set_type		= irq_chip_set_type_parent,
79 	.irq_compose_msi_msg	= gicp_compose_msi_msg,
80 };
81 
82 static int gicp_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
83 				 unsigned int nr_irqs, void *args)
84 {
85 	struct mvebu_gicp *gicp = domain->host_data;
86 	struct irq_fwspec fwspec;
87 	unsigned int hwirq;
88 	int ret;
89 
90 	spin_lock(&gicp->spi_lock);
91 	hwirq = find_first_zero_bit(gicp->spi_bitmap, gicp->spi_cnt);
92 	if (hwirq == gicp->spi_cnt) {
93 		spin_unlock(&gicp->spi_lock);
94 		return -ENOSPC;
95 	}
96 	__set_bit(hwirq, gicp->spi_bitmap);
97 	spin_unlock(&gicp->spi_lock);
98 
99 	fwspec.fwnode = domain->parent->fwnode;
100 	fwspec.param_count = 3;
101 	fwspec.param[0] = GIC_SPI;
102 	fwspec.param[1] = gicp_idx_to_spi(gicp, hwirq) - 32;
103 	/*
104 	 * Assume edge rising for now, it will be properly set when
105 	 * ->set_type() is called
106 	 */
107 	fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
108 
109 	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
110 	if (ret) {
111 		dev_err(gicp->dev, "Cannot allocate parent IRQ\n");
112 		goto free_hwirq;
113 	}
114 
115 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
116 					    &gicp_irq_chip, gicp);
117 	if (ret)
118 		goto free_irqs_parent;
119 
120 	return 0;
121 
122 free_irqs_parent:
123 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
124 free_hwirq:
125 	spin_lock(&gicp->spi_lock);
126 	__clear_bit(hwirq, gicp->spi_bitmap);
127 	spin_unlock(&gicp->spi_lock);
128 	return ret;
129 }
130 
131 static void gicp_irq_domain_free(struct irq_domain *domain,
132 				 unsigned int virq, unsigned int nr_irqs)
133 {
134 	struct mvebu_gicp *gicp = domain->host_data;
135 	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
136 
137 	if (d->hwirq >= gicp->spi_cnt) {
138 		dev_err(gicp->dev, "Invalid hwirq %lu\n", d->hwirq);
139 		return;
140 	}
141 
142 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
143 
144 	spin_lock(&gicp->spi_lock);
145 	__clear_bit(d->hwirq, gicp->spi_bitmap);
146 	spin_unlock(&gicp->spi_lock);
147 }
148 
149 static const struct irq_domain_ops gicp_domain_ops = {
150 	.select	= msi_lib_irq_domain_select,
151 	.alloc	= gicp_irq_domain_alloc,
152 	.free	= gicp_irq_domain_free,
153 };
154 
155 #define GICP_MSI_FLAGS_REQUIRED  (MSI_FLAG_USE_DEF_DOM_OPS |	\
156 				  MSI_FLAG_USE_DEF_CHIP_OPS)
157 
158 #define GICP_MSI_FLAGS_SUPPORTED (MSI_GENERIC_FLAGS_MASK |	\
159 				  MSI_FLAG_LEVEL_CAPABLE)
160 
161 static const struct msi_parent_ops gicp_msi_parent_ops = {
162 	.supported_flags	= GICP_MSI_FLAGS_SUPPORTED,
163 	.required_flags		= GICP_MSI_FLAGS_REQUIRED,
164 	.bus_select_token       = DOMAIN_BUS_GENERIC_MSI,
165 	.bus_select_mask	= MATCH_PLATFORM_MSI,
166 	.prefix			= "GICP-",
167 	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
168 };
169 
170 static int mvebu_gicp_probe(struct platform_device *pdev)
171 {
172 	struct irq_domain *inner_domain, *parent_domain;
173 	struct device_node *node = pdev->dev.of_node;
174 	struct device_node *irq_parent_dn;
175 	struct mvebu_gicp *gicp;
176 	int ret, i;
177 
178 	gicp = devm_kzalloc(&pdev->dev, sizeof(*gicp), GFP_KERNEL);
179 	if (!gicp)
180 		return -ENOMEM;
181 
182 	gicp->dev = &pdev->dev;
183 	spin_lock_init(&gicp->spi_lock);
184 
185 	gicp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
186 	if (!gicp->res)
187 		return -ENODEV;
188 
189 	ret = of_property_count_u32_elems(node, "marvell,spi-ranges");
190 	if (ret < 0)
191 		return ret;
192 
193 	gicp->spi_ranges_cnt = ret / 2;
194 
195 	gicp->spi_ranges =
196 		devm_kcalloc(&pdev->dev,
197 			     gicp->spi_ranges_cnt,
198 			     sizeof(struct mvebu_gicp_spi_range),
199 			     GFP_KERNEL);
200 	if (!gicp->spi_ranges)
201 		return -ENOMEM;
202 
203 	for (i = 0; i < gicp->spi_ranges_cnt; i++) {
204 		of_property_read_u32_index(node, "marvell,spi-ranges",
205 					   i * 2,
206 					   &gicp->spi_ranges[i].start);
207 
208 		of_property_read_u32_index(node, "marvell,spi-ranges",
209 					   i * 2 + 1,
210 					   &gicp->spi_ranges[i].count);
211 
212 		gicp->spi_cnt += gicp->spi_ranges[i].count;
213 	}
214 
215 	gicp->spi_bitmap = devm_bitmap_zalloc(&pdev->dev, gicp->spi_cnt, GFP_KERNEL);
216 	if (!gicp->spi_bitmap)
217 		return -ENOMEM;
218 
219 	irq_parent_dn = of_irq_find_parent(node);
220 	if (!irq_parent_dn) {
221 		dev_err(&pdev->dev, "failed to find parent IRQ node\n");
222 		return -ENODEV;
223 	}
224 
225 	parent_domain = irq_find_host(irq_parent_dn);
226 	of_node_put(irq_parent_dn);
227 	if (!parent_domain) {
228 		dev_err(&pdev->dev, "failed to find parent IRQ domain\n");
229 		return -ENODEV;
230 	}
231 
232 	inner_domain = irq_domain_create_hierarchy(parent_domain, 0,
233 						   gicp->spi_cnt,
234 						   of_node_to_fwnode(node),
235 						   &gicp_domain_ops, gicp);
236 	if (!inner_domain)
237 		return -ENOMEM;
238 
239 	irq_domain_update_bus_token(inner_domain, DOMAIN_BUS_GENERIC_MSI);
240 	inner_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT;
241 	inner_domain->msi_parent_ops = &gicp_msi_parent_ops;
242 	return 0;
243 }
244 
245 static const struct of_device_id mvebu_gicp_of_match[] = {
246 	{ .compatible = "marvell,ap806-gicp", },
247 	{},
248 };
249 
250 static struct platform_driver mvebu_gicp_driver = {
251 	.probe  = mvebu_gicp_probe,
252 	.driver = {
253 		.name = "mvebu-gicp",
254 		.of_match_table = mvebu_gicp_of_match,
255 	},
256 };
257 builtin_platform_driver(mvebu_gicp_driver);
258