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e2c37d90 AP |
1 | /* |
2 | * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for | |
3 | * generation of the interrupt. | |
4 | * | |
5 | * Copyright © 2013 Alistair Popple <alistair@popple.id.au> IBM Corporation | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the | |
9 | * Free Software Foundation; either version 2 of the License, or (at your | |
10 | * option) any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/msi.h> | |
16 | #include <linux/of.h> | |
17 | #include <linux/of_platform.h> | |
18 | #include <linux/pci.h> | |
19 | #include <linux/semaphore.h> | |
20 | #include <asm/msi_bitmap.h> | |
21 | ||
22 | struct ppc4xx_hsta_msi { | |
23 | struct device *dev; | |
24 | ||
25 | /* The ioremapped HSTA MSI IO space */ | |
26 | u32 __iomem *data; | |
27 | ||
28 | /* Physical address of HSTA MSI IO space */ | |
29 | u64 address; | |
30 | struct msi_bitmap bmp; | |
31 | ||
32 | /* An array mapping offsets to hardware IRQs */ | |
33 | int *irq_map; | |
34 | ||
35 | /* Number of hwirqs supported */ | |
36 | int irq_count; | |
37 | }; | |
38 | static struct ppc4xx_hsta_msi ppc4xx_hsta_msi; | |
39 | ||
40 | static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) | |
41 | { | |
42 | struct msi_msg msg; | |
43 | struct msi_desc *entry; | |
44 | int irq, hwirq; | |
45 | u64 addr; | |
46 | ||
6b2fd7ef AG |
47 | /* We don't support MSI-X */ |
48 | if (type == PCI_CAP_ID_MSIX) { | |
49 | pr_debug("%s: MSI-X not supported.\n", __func__); | |
50 | return -EINVAL; | |
51 | } | |
52 | ||
e2c37d90 AP |
53 | list_for_each_entry(entry, &dev->msi_list, list) { |
54 | irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1); | |
55 | if (irq < 0) { | |
56 | pr_debug("%s: Failed to allocate msi interrupt\n", | |
57 | __func__); | |
58 | return irq; | |
59 | } | |
60 | ||
61 | hwirq = ppc4xx_hsta_msi.irq_map[irq]; | |
62 | if (hwirq == NO_IRQ) { | |
63 | pr_err("%s: Failed mapping irq %d\n", __func__, irq); | |
64 | return -EINVAL; | |
65 | } | |
66 | ||
67 | /* | |
68 | * HSTA generates interrupts on writes to 128-bit aligned | |
69 | * addresses. | |
70 | */ | |
71 | addr = ppc4xx_hsta_msi.address + irq*0x10; | |
72 | msg.address_hi = upper_32_bits(addr); | |
73 | msg.address_lo = lower_32_bits(addr); | |
74 | ||
75 | /* Data is not used by the HSTA. */ | |
76 | msg.data = 0; | |
77 | ||
78 | pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq, | |
79 | (((u64) msg.address_hi) << 32) | msg.address_lo); | |
80 | ||
81 | if (irq_set_msi_desc(hwirq, entry)) { | |
82 | pr_err( | |
83 | "%s: Invalid hwirq %d specified in device tree\n", | |
84 | __func__, hwirq); | |
85 | msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); | |
86 | return -EINVAL; | |
87 | } | |
83a18912 | 88 | pci_write_msi_msg(hwirq, &msg); |
e2c37d90 AP |
89 | } |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | static int hsta_find_hwirq_offset(int hwirq) | |
95 | { | |
96 | int irq; | |
97 | ||
98 | /* Find the offset given the hwirq */ | |
99 | for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++) | |
100 | if (ppc4xx_hsta_msi.irq_map[irq] == hwirq) | |
101 | return irq; | |
102 | ||
103 | return -EINVAL; | |
104 | } | |
105 | ||
106 | static void hsta_teardown_msi_irqs(struct pci_dev *dev) | |
107 | { | |
108 | struct msi_desc *entry; | |
109 | int irq; | |
110 | ||
111 | list_for_each_entry(entry, &dev->msi_list, list) { | |
112 | if (entry->irq == NO_IRQ) | |
113 | continue; | |
114 | ||
115 | irq = hsta_find_hwirq_offset(entry->irq); | |
116 | ||
117 | /* entry->irq should always be in irq_map */ | |
118 | BUG_ON(irq < 0); | |
119 | irq_set_msi_desc(entry->irq, NULL); | |
120 | msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); | |
121 | pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__, | |
122 | entry->irq, irq); | |
123 | } | |
124 | } | |
125 | ||
e2c37d90 AP |
126 | static int hsta_msi_probe(struct platform_device *pdev) |
127 | { | |
128 | struct device *dev = &pdev->dev; | |
129 | struct resource *mem; | |
130 | int irq, ret, irq_count; | |
131 | ||
132 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
133 | if (IS_ERR(mem)) { | |
134 | dev_err(dev, "Unable to get mmio space\n"); | |
135 | return -EINVAL; | |
136 | } | |
137 | ||
138 | irq_count = of_irq_count(dev->of_node); | |
139 | if (!irq_count) { | |
140 | dev_err(dev, "Unable to find IRQ range\n"); | |
141 | return -EINVAL; | |
142 | } | |
143 | ||
144 | ppc4xx_hsta_msi.dev = dev; | |
145 | ppc4xx_hsta_msi.address = mem->start; | |
146 | ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem)); | |
147 | ppc4xx_hsta_msi.irq_count = irq_count; | |
148 | if (IS_ERR(ppc4xx_hsta_msi.data)) { | |
149 | dev_err(dev, "Unable to map memory\n"); | |
150 | return -ENOMEM; | |
151 | } | |
152 | ||
153 | ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node); | |
154 | if (ret) | |
155 | goto out; | |
156 | ||
157 | ppc4xx_hsta_msi.irq_map = kmalloc(sizeof(int) * irq_count, GFP_KERNEL); | |
158 | if (IS_ERR(ppc4xx_hsta_msi.irq_map)) { | |
159 | ret = -ENOMEM; | |
160 | goto out1; | |
161 | } | |
162 | ||
163 | /* Setup a mapping from irq offsets to hardware irq numbers */ | |
164 | for (irq = 0; irq < irq_count; irq++) { | |
165 | ppc4xx_hsta_msi.irq_map[irq] = | |
166 | irq_of_parse_and_map(dev->of_node, irq); | |
167 | if (ppc4xx_hsta_msi.irq_map[irq] == NO_IRQ) { | |
168 | dev_err(dev, "Unable to map IRQ\n"); | |
169 | ret = -EINVAL; | |
170 | goto out2; | |
171 | } | |
172 | } | |
173 | ||
174 | ppc_md.setup_msi_irqs = hsta_setup_msi_irqs; | |
175 | ppc_md.teardown_msi_irqs = hsta_teardown_msi_irqs; | |
e2c37d90 AP |
176 | return 0; |
177 | ||
178 | out2: | |
179 | kfree(ppc4xx_hsta_msi.irq_map); | |
180 | ||
181 | out1: | |
182 | msi_bitmap_free(&ppc4xx_hsta_msi.bmp); | |
183 | ||
184 | out: | |
185 | iounmap(ppc4xx_hsta_msi.data); | |
186 | return ret; | |
187 | } | |
188 | ||
189 | static const struct of_device_id hsta_msi_ids[] = { | |
190 | { | |
191 | .compatible = "ibm,hsta-msi", | |
192 | }, | |
193 | {} | |
194 | }; | |
195 | ||
196 | static struct platform_driver hsta_msi_driver = { | |
197 | .probe = hsta_msi_probe, | |
198 | .driver = { | |
199 | .name = "hsta-msi", | |
e2c37d90 AP |
200 | .of_match_table = hsta_msi_ids, |
201 | }, | |
202 | }; | |
203 | ||
204 | static int hsta_msi_init(void) | |
205 | { | |
206 | return platform_driver_register(&hsta_msi_driver); | |
207 | } | |
208 | subsys_initcall(hsta_msi_init); |