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 <dt-bindings/interrupt-controller/arm-gic.h>
21 
22 #define GICP_SETSPI_NSR_OFFSET	0x0
23 #define GICP_CLRSPI_NSR_OFFSET	0x8
24 
25 struct mvebu_gicp_spi_range {
26 	unsigned int start;
27 	unsigned int count;
28 };
29 
30 struct mvebu_gicp {
31 	struct mvebu_gicp_spi_range *spi_ranges;
32 	unsigned int spi_ranges_cnt;
33 	unsigned int spi_cnt;
34 	unsigned long *spi_bitmap;
35 	spinlock_t spi_lock;
36 	struct resource *res;
37 	struct device *dev;
38 };
39 
40 static int gicp_idx_to_spi(struct mvebu_gicp *gicp, int idx)
41 {
42 	int i;
43 
44 	for (i = 0; i < gicp->spi_ranges_cnt; i++) {
45 		struct mvebu_gicp_spi_range *r = &gicp->spi_ranges[i];
46 
47 		if (idx < r->count)
48 			return r->start + idx;
49 
50 		idx -= r->count;
51 	}
52 
53 	return -EINVAL;
54 }
55 
56 static void gicp_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
57 {
58 	struct mvebu_gicp *gicp = data->chip_data;
59 	phys_addr_t setspi = gicp->res->start + GICP_SETSPI_NSR_OFFSET;
60 	phys_addr_t clrspi = gicp->res->start + GICP_CLRSPI_NSR_OFFSET;
61 
62 	msg[0].data = data->hwirq;
63 	msg[0].address_lo = lower_32_bits(setspi);
64 	msg[0].address_hi = upper_32_bits(setspi);
65 	msg[1].data = data->hwirq;
66 	msg[1].address_lo = lower_32_bits(clrspi);
67 	msg[1].address_hi = upper_32_bits(clrspi);
68 }
69 
70 static struct irq_chip gicp_irq_chip = {
71 	.name			= "GICP",
72 	.irq_mask		= irq_chip_mask_parent,
73 	.irq_unmask		= irq_chip_unmask_parent,
74 	.irq_eoi		= irq_chip_eoi_parent,
75 	.irq_set_affinity	= irq_chip_set_affinity_parent,
76 	.irq_set_type		= irq_chip_set_type_parent,
77 	.irq_compose_msi_msg	= gicp_compose_msi_msg,
78 };
79 
80 static int gicp_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
81 				 unsigned int nr_irqs, void *args)
82 {
83 	struct mvebu_gicp *gicp = domain->host_data;
84 	struct irq_fwspec fwspec;
85 	unsigned int hwirq;
86 	int ret;
87 
88 	spin_lock(&gicp->spi_lock);
89 	hwirq = find_first_zero_bit(gicp->spi_bitmap, gicp->spi_cnt);
90 	if (hwirq == gicp->spi_cnt) {
91 		spin_unlock(&gicp->spi_lock);
92 		return -ENOSPC;
93 	}
94 	__set_bit(hwirq, gicp->spi_bitmap);
95 	spin_unlock(&gicp->spi_lock);
96 
97 	fwspec.fwnode = domain->parent->fwnode;
98 	fwspec.param_count = 3;
99 	fwspec.param[0] = GIC_SPI;
100 	fwspec.param[1] = gicp_idx_to_spi(gicp, hwirq) - 32;
101 	/*
102 	 * Assume edge rising for now, it will be properly set when
103 	 * ->set_type() is called
104 	 */
105 	fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
106 
107 	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
108 	if (ret) {
109 		dev_err(gicp->dev, "Cannot allocate parent IRQ\n");
110 		goto free_hwirq;
111 	}
112 
113 	ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
114 					    &gicp_irq_chip, gicp);
115 	if (ret)
116 		goto free_irqs_parent;
117 
118 	return 0;
119 
120 free_irqs_parent:
121 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
122 free_hwirq:
123 	spin_lock(&gicp->spi_lock);
124 	__clear_bit(hwirq, gicp->spi_bitmap);
125 	spin_unlock(&gicp->spi_lock);
126 	return ret;
127 }
128 
129 static void gicp_irq_domain_free(struct irq_domain *domain,
130 				 unsigned int virq, unsigned int nr_irqs)
131 {
132 	struct mvebu_gicp *gicp = domain->host_data;
133 	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
134 
135 	if (d->hwirq >= gicp->spi_cnt) {
136 		dev_err(gicp->dev, "Invalid hwirq %lu\n", d->hwirq);
137 		return;
138 	}
139 
140 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
141 
142 	spin_lock(&gicp->spi_lock);
143 	__clear_bit(d->hwirq, gicp->spi_bitmap);
144 	spin_unlock(&gicp->spi_lock);
145 }
146 
147 static const struct irq_domain_ops gicp_domain_ops = {
148 	.alloc	= gicp_irq_domain_alloc,
149 	.free	= gicp_irq_domain_free,
150 };
151 
152 static struct irq_chip gicp_msi_irq_chip = {
153 	.name		= "GICP",
154 	.irq_set_type	= irq_chip_set_type_parent,
155 	.flags		= IRQCHIP_SUPPORTS_LEVEL_MSI,
156 };
157 
158 static struct msi_domain_ops gicp_msi_ops = {
159 };
160 
161 static struct msi_domain_info gicp_msi_domain_info = {
162 	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
163 		   MSI_FLAG_LEVEL_CAPABLE),
164 	.ops	= &gicp_msi_ops,
165 	.chip	= &gicp_msi_irq_chip,
166 };
167 
168 static int mvebu_gicp_probe(struct platform_device *pdev)
169 {
170 	struct mvebu_gicp *gicp;
171 	struct irq_domain *inner_domain, *plat_domain, *parent_domain;
172 	struct device_node *node = pdev->dev.of_node;
173 	struct device_node *irq_parent_dn;
174 	int ret, i;
175 
176 	gicp = devm_kzalloc(&pdev->dev, sizeof(*gicp), GFP_KERNEL);
177 	if (!gicp)
178 		return -ENOMEM;
179 
180 	gicp->dev = &pdev->dev;
181 	spin_lock_init(&gicp->spi_lock);
182 
183 	gicp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
184 	if (!gicp->res)
185 		return -ENODEV;
186 
187 	ret = of_property_count_u32_elems(node, "marvell,spi-ranges");
188 	if (ret < 0)
189 		return ret;
190 
191 	gicp->spi_ranges_cnt = ret / 2;
192 
193 	gicp->spi_ranges =
194 		devm_kcalloc(&pdev->dev,
195 			     gicp->spi_ranges_cnt,
196 			     sizeof(struct mvebu_gicp_spi_range),
197 			     GFP_KERNEL);
198 	if (!gicp->spi_ranges)
199 		return -ENOMEM;
200 
201 	for (i = 0; i < gicp->spi_ranges_cnt; i++) {
202 		of_property_read_u32_index(node, "marvell,spi-ranges",
203 					   i * 2,
204 					   &gicp->spi_ranges[i].start);
205 
206 		of_property_read_u32_index(node, "marvell,spi-ranges",
207 					   i * 2 + 1,
208 					   &gicp->spi_ranges[i].count);
209 
210 		gicp->spi_cnt += gicp->spi_ranges[i].count;
211 	}
212 
213 	gicp->spi_bitmap = devm_bitmap_zalloc(&pdev->dev, gicp->spi_cnt, GFP_KERNEL);
214 	if (!gicp->spi_bitmap)
215 		return -ENOMEM;
216 
217 	irq_parent_dn = of_irq_find_parent(node);
218 	if (!irq_parent_dn) {
219 		dev_err(&pdev->dev, "failed to find parent IRQ node\n");
220 		return -ENODEV;
221 	}
222 
223 	parent_domain = irq_find_host(irq_parent_dn);
224 	if (!parent_domain) {
225 		dev_err(&pdev->dev, "failed to find parent IRQ domain\n");
226 		return -ENODEV;
227 	}
228 
229 	inner_domain = irq_domain_create_hierarchy(parent_domain, 0,
230 						   gicp->spi_cnt,
231 						   of_node_to_fwnode(node),
232 						   &gicp_domain_ops, gicp);
233 	if (!inner_domain)
234 		return -ENOMEM;
235 
236 
237 	plat_domain = platform_msi_create_irq_domain(of_node_to_fwnode(node),
238 						     &gicp_msi_domain_info,
239 						     inner_domain);
240 	if (!plat_domain) {
241 		irq_domain_remove(inner_domain);
242 		return -ENOMEM;
243 	}
244 
245 	platform_set_drvdata(pdev, gicp);
246 
247 	return 0;
248 }
249 
250 static const struct of_device_id mvebu_gicp_of_match[] = {
251 	{ .compatible = "marvell,ap806-gicp", },
252 	{},
253 };
254 
255 static struct platform_driver mvebu_gicp_driver = {
256 	.probe  = mvebu_gicp_probe,
257 	.driver = {
258 		.name = "mvebu-gicp",
259 		.of_match_table = mvebu_gicp_of_match,
260 	},
261 };
262 builtin_platform_driver(mvebu_gicp_driver);
263