2 * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for
3 * generation of the interrupt.
5 * Copyright © 2013 Alistair Popple <alistair@popple.id.au> IBM Corporation
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.
13 #include <linux/kernel.h>
14 #include <linux/interrupt.h>
15 #include <linux/msi.h>
17 #include <linux/of_platform.h>
18 #include <linux/pci.h>
19 #include <linux/semaphore.h>
20 #include <asm/msi_bitmap.h>
22 struct ppc4xx_hsta_msi {
25 /* The ioremapped HSTA MSI IO space */
28 /* Physical address of HSTA MSI IO space */
30 struct msi_bitmap bmp;
32 /* An array mapping offsets to hardware IRQs */
35 /* Number of hwirqs supported */
38 static struct ppc4xx_hsta_msi ppc4xx_hsta_msi;
40 static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
43 struct msi_desc *entry;
47 /* We don't support MSI-X */
48 if (type == PCI_CAP_ID_MSIX) {
49 pr_debug("%s: MSI-X not supported.\n", __func__);
53 list_for_each_entry(entry, &dev->msi_list, list) {
54 irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1);
56 pr_debug("%s: Failed to allocate msi interrupt\n",
61 hwirq = ppc4xx_hsta_msi.irq_map[irq];
62 if (hwirq == NO_IRQ) {
63 pr_err("%s: Failed mapping irq %d\n", __func__, irq);
68 * HSTA generates interrupts on writes to 128-bit aligned
71 addr = ppc4xx_hsta_msi.address + irq*0x10;
72 msg.address_hi = upper_32_bits(addr);
73 msg.address_lo = lower_32_bits(addr);
75 /* Data is not used by the HSTA. */
78 pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq,
79 (((u64) msg.address_hi) << 32) | msg.address_lo);
81 if (irq_set_msi_desc(hwirq, entry)) {
83 "%s: Invalid hwirq %d specified in device tree\n",
85 msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
88 pci_write_msi_msg(hwirq, &msg);
94 static int hsta_find_hwirq_offset(int hwirq)
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)
106 static void hsta_teardown_msi_irqs(struct pci_dev *dev)
108 struct msi_desc *entry;
111 list_for_each_entry(entry, &dev->msi_list, list) {
112 if (entry->irq == NO_IRQ)
115 irq = hsta_find_hwirq_offset(entry->irq);
117 /* entry->irq should always be in irq_map */
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__,
126 static int hsta_msi_probe(struct platform_device *pdev)
128 struct device *dev = &pdev->dev;
129 struct resource *mem;
130 int irq, ret, irq_count;
131 struct pci_controller *phb;
133 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
135 dev_err(dev, "Unable to get mmio space\n");
139 irq_count = of_irq_count(dev->of_node);
141 dev_err(dev, "Unable to find IRQ range\n");
145 ppc4xx_hsta_msi.dev = dev;
146 ppc4xx_hsta_msi.address = mem->start;
147 ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem));
148 ppc4xx_hsta_msi.irq_count = irq_count;
149 if (!ppc4xx_hsta_msi.data) {
150 dev_err(dev, "Unable to map memory\n");
154 ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node);
158 ppc4xx_hsta_msi.irq_map = kmalloc(sizeof(int) * irq_count, GFP_KERNEL);
159 if (IS_ERR(ppc4xx_hsta_msi.irq_map)) {
164 /* Setup a mapping from irq offsets to hardware irq numbers */
165 for (irq = 0; irq < irq_count; irq++) {
166 ppc4xx_hsta_msi.irq_map[irq] =
167 irq_of_parse_and_map(dev->of_node, irq);
168 if (ppc4xx_hsta_msi.irq_map[irq] == NO_IRQ) {
169 dev_err(dev, "Unable to map IRQ\n");
175 list_for_each_entry(phb, &hose_list, list_node) {
176 phb->controller_ops.setup_msi_irqs = hsta_setup_msi_irqs;
177 phb->controller_ops.teardown_msi_irqs = hsta_teardown_msi_irqs;
182 kfree(ppc4xx_hsta_msi.irq_map);
185 msi_bitmap_free(&ppc4xx_hsta_msi.bmp);
188 iounmap(ppc4xx_hsta_msi.data);
192 static const struct of_device_id hsta_msi_ids[] = {
194 .compatible = "ibm,hsta-msi",
199 static struct platform_driver hsta_msi_driver = {
200 .probe = hsta_msi_probe,
203 .of_match_table = hsta_msi_ids,
207 static int hsta_msi_init(void)
209 return platform_driver_register(&hsta_msi_driver);
211 subsys_initcall(hsta_msi_init);