1 /*
2 * Copyright (C) 2016 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 #define pr_fmt(fmt) "GIC-ODMI: " fmt
12
13 #include <linux/irq.h>
14 #include <linux/irqchip.h>
15 #include <linux/irqdomain.h>
16 #include <linux/kernel.h>
17 #include <linux/msi.h>
18 #include <linux/of_address.h>
19 #include <linux/slab.h>
20 #include <dt-bindings/interrupt-controller/arm-gic.h>
21
22 #define GICP_ODMIN_SET 0x40
23 #define GICP_ODMI_INT_NUM_SHIFT 12
24 #define GICP_ODMIN_GM_EP_R0 0x110
25 #define GICP_ODMIN_GM_EP_R1 0x114
26 #define GICP_ODMIN_GM_EA_R0 0x108
27 #define GICP_ODMIN_GM_EA_R1 0x118
28
29 /*
30 * We don't support the group events, so we simply have 8 interrupts
31 * per frame.
32 */
33 #define NODMIS_SHIFT 3
34 #define NODMIS_PER_FRAME (1 << NODMIS_SHIFT)
35 #define NODMIS_MASK (NODMIS_PER_FRAME - 1)
36
37 struct odmi_data {
38 struct resource res;
39 void __iomem *base;
40 unsigned int spi_base;
41 };
42
43 static struct odmi_data *odmis;
44 static unsigned long *odmis_bm;
45 static unsigned int odmis_count;
46
47 /* Protects odmis_bm */
48 static DEFINE_SPINLOCK(odmis_bm_lock);
49
odmi_compose_msi_msg(struct irq_data * d,struct msi_msg * msg)50 static void odmi_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
51 {
52 struct odmi_data *odmi;
53 phys_addr_t addr;
54 unsigned int odmin;
55
56 if (WARN_ON(d->hwirq >= odmis_count * NODMIS_PER_FRAME))
57 return;
58
59 odmi = &odmis[d->hwirq >> NODMIS_SHIFT];
60 odmin = d->hwirq & NODMIS_MASK;
61
62 addr = odmi->res.start + GICP_ODMIN_SET;
63
64 msg->address_hi = upper_32_bits(addr);
65 msg->address_lo = lower_32_bits(addr);
66 msg->data = odmin << GICP_ODMI_INT_NUM_SHIFT;
67 }
68
69 static struct irq_chip odmi_irq_chip = {
70 .name = "ODMI",
71 .irq_mask = irq_chip_mask_parent,
72 .irq_unmask = irq_chip_unmask_parent,
73 .irq_eoi = irq_chip_eoi_parent,
74 .irq_set_affinity = irq_chip_set_affinity_parent,
75 .irq_compose_msi_msg = odmi_compose_msi_msg,
76 };
77
odmi_irq_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * args)78 static int odmi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
79 unsigned int nr_irqs, void *args)
80 {
81 struct odmi_data *odmi = NULL;
82 struct irq_fwspec fwspec;
83 struct irq_data *d;
84 unsigned int hwirq, odmin;
85 int ret;
86
87 spin_lock(&odmis_bm_lock);
88 hwirq = find_first_zero_bit(odmis_bm, NODMIS_PER_FRAME * odmis_count);
89 if (hwirq >= NODMIS_PER_FRAME * odmis_count) {
90 spin_unlock(&odmis_bm_lock);
91 return -ENOSPC;
92 }
93
94 __set_bit(hwirq, odmis_bm);
95 spin_unlock(&odmis_bm_lock);
96
97 odmi = &odmis[hwirq >> NODMIS_SHIFT];
98 odmin = hwirq & NODMIS_MASK;
99
100 fwspec.fwnode = domain->parent->fwnode;
101 fwspec.param_count = 3;
102 fwspec.param[0] = GIC_SPI;
103 fwspec.param[1] = odmi->spi_base - 32 + odmin;
104 fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
105
106 ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
107 if (ret) {
108 pr_err("Cannot allocate parent IRQ\n");
109 spin_lock(&odmis_bm_lock);
110 __clear_bit(odmin, odmis_bm);
111 spin_unlock(&odmis_bm_lock);
112 return ret;
113 }
114
115 /* Configure the interrupt line to be edge */
116 d = irq_domain_get_irq_data(domain->parent, virq);
117 d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
118
119 irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
120 &odmi_irq_chip, NULL);
121
122 return 0;
123 }
124
odmi_irq_domain_free(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs)125 static void odmi_irq_domain_free(struct irq_domain *domain,
126 unsigned int virq, unsigned int nr_irqs)
127 {
128 struct irq_data *d = irq_domain_get_irq_data(domain, virq);
129
130 if (d->hwirq >= odmis_count * NODMIS_PER_FRAME) {
131 pr_err("Failed to teardown msi. Invalid hwirq %lu\n", d->hwirq);
132 return;
133 }
134
135 irq_domain_free_irqs_parent(domain, virq, nr_irqs);
136
137 /* Actually free the MSI */
138 spin_lock(&odmis_bm_lock);
139 __clear_bit(d->hwirq, odmis_bm);
140 spin_unlock(&odmis_bm_lock);
141 }
142
143 static const struct irq_domain_ops odmi_domain_ops = {
144 .alloc = odmi_irq_domain_alloc,
145 .free = odmi_irq_domain_free,
146 };
147
148 static struct irq_chip odmi_msi_irq_chip = {
149 .name = "ODMI",
150 };
151
152 static struct msi_domain_ops odmi_msi_ops = {
153 };
154
155 static struct msi_domain_info odmi_msi_domain_info = {
156 .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
157 .ops = &odmi_msi_ops,
158 .chip = &odmi_msi_irq_chip,
159 };
160
mvebu_odmi_init(struct device_node * node,struct device_node * parent)161 static int __init mvebu_odmi_init(struct device_node *node,
162 struct device_node *parent)
163 {
164 struct irq_domain *parent_domain, *inner_domain, *plat_domain;
165 int ret, i;
166
167 if (of_property_read_u32(node, "marvell,odmi-frames", &odmis_count))
168 return -EINVAL;
169
170 odmis = kcalloc(odmis_count, sizeof(struct odmi_data), GFP_KERNEL);
171 if (!odmis)
172 return -ENOMEM;
173
174 odmis_bm = bitmap_zalloc(odmis_count * NODMIS_PER_FRAME, GFP_KERNEL);
175 if (!odmis_bm) {
176 ret = -ENOMEM;
177 goto err_alloc;
178 }
179
180 for (i = 0; i < odmis_count; i++) {
181 struct odmi_data *odmi = &odmis[i];
182
183 ret = of_address_to_resource(node, i, &odmi->res);
184 if (ret)
185 goto err_unmap;
186
187 odmi->base = of_io_request_and_map(node, i, "odmi");
188 if (IS_ERR(odmi->base)) {
189 ret = PTR_ERR(odmi->base);
190 goto err_unmap;
191 }
192
193 if (of_property_read_u32_index(node, "marvell,spi-base",
194 i, &odmi->spi_base)) {
195 ret = -EINVAL;
196 goto err_unmap;
197 }
198 }
199
200 parent_domain = irq_find_host(parent);
201
202 inner_domain = irq_domain_create_hierarchy(parent_domain, 0,
203 odmis_count * NODMIS_PER_FRAME,
204 of_node_to_fwnode(node),
205 &odmi_domain_ops, NULL);
206 if (!inner_domain) {
207 ret = -ENOMEM;
208 goto err_unmap;
209 }
210
211 plat_domain = platform_msi_create_irq_domain(of_node_to_fwnode(node),
212 &odmi_msi_domain_info,
213 inner_domain);
214 if (!plat_domain) {
215 ret = -ENOMEM;
216 goto err_remove_inner;
217 }
218
219 return 0;
220
221 err_remove_inner:
222 irq_domain_remove(inner_domain);
223 err_unmap:
224 for (i = 0; i < odmis_count; i++) {
225 struct odmi_data *odmi = &odmis[i];
226
227 if (odmi->base && !IS_ERR(odmi->base))
228 iounmap(odmis[i].base);
229 }
230 bitmap_free(odmis_bm);
231 err_alloc:
232 kfree(odmis);
233 return ret;
234 }
235
236 IRQCHIP_DECLARE(mvebu_odmi, "marvell,odmi-controller", mvebu_odmi_init);
237