1 /*
2 * Copyright (C) 2007 Google, Inc.
3 * Copyright (C) 2011 Intel, Inc.
4 * Copyright (C) 2013 Intel, Inc.
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 */
16
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/irq.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 #include <linux/io.h>
24
25 #define PDEV_BUS_OP_DONE (0x00)
26 #define PDEV_BUS_OP_REMOVE_DEV (0x04)
27 #define PDEV_BUS_OP_ADD_DEV (0x08)
28
29 #define PDEV_BUS_OP_INIT (0x00)
30
31 #define PDEV_BUS_OP (0x00)
32 #define PDEV_BUS_GET_NAME (0x04)
33 #define PDEV_BUS_NAME_LEN (0x08)
34 #define PDEV_BUS_ID (0x0c)
35 #define PDEV_BUS_IO_BASE (0x10)
36 #define PDEV_BUS_IO_SIZE (0x14)
37 #define PDEV_BUS_IRQ (0x18)
38 #define PDEV_BUS_IRQ_COUNT (0x1c)
39 #define PDEV_BUS_GET_NAME_HIGH (0x20)
40
41 struct pdev_bus_dev {
42 struct list_head list;
43 struct platform_device pdev;
44 struct resource resources[0];
45 };
46
47 static void goldfish_pdev_worker(struct work_struct *work);
48
49 static void __iomem *pdev_bus_base;
50 static unsigned long pdev_bus_addr;
51 static unsigned long pdev_bus_len;
52 static u32 pdev_bus_irq;
53 static LIST_HEAD(pdev_bus_new_devices);
54 static LIST_HEAD(pdev_bus_registered_devices);
55 static LIST_HEAD(pdev_bus_removed_devices);
56 static DECLARE_WORK(pdev_bus_worker, goldfish_pdev_worker);
57
58
goldfish_pdev_worker(struct work_struct * work)59 static void goldfish_pdev_worker(struct work_struct *work)
60 {
61 int ret;
62 struct pdev_bus_dev *pos, *n;
63
64 list_for_each_entry_safe(pos, n, &pdev_bus_removed_devices, list) {
65 list_del(&pos->list);
66 platform_device_unregister(&pos->pdev);
67 kfree(pos);
68 }
69 list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
70 list_del(&pos->list);
71 ret = platform_device_register(&pos->pdev);
72 if (ret)
73 pr_err("goldfish_pdev_worker failed to register device, %s\n",
74 pos->pdev.name);
75 list_add_tail(&pos->list, &pdev_bus_registered_devices);
76 }
77 }
78
goldfish_pdev_remove(void)79 static void goldfish_pdev_remove(void)
80 {
81 struct pdev_bus_dev *pos, *n;
82 u32 base;
83
84 base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
85
86 list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
87 if (pos->resources[0].start == base) {
88 list_del(&pos->list);
89 kfree(pos);
90 return;
91 }
92 }
93 list_for_each_entry_safe(pos, n, &pdev_bus_registered_devices, list) {
94 if (pos->resources[0].start == base) {
95 list_del(&pos->list);
96 list_add_tail(&pos->list, &pdev_bus_removed_devices);
97 schedule_work(&pdev_bus_worker);
98 return;
99 }
100 };
101 pr_err("goldfish_pdev_remove could not find device at %x\n", base);
102 }
103
goldfish_new_pdev(void)104 static int goldfish_new_pdev(void)
105 {
106 struct pdev_bus_dev *dev;
107 u32 name_len;
108 u32 irq = -1, irq_count;
109 int resource_count = 2;
110 u32 base;
111 char *name;
112
113 base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);
114
115 irq_count = readl(pdev_bus_base + PDEV_BUS_IRQ_COUNT);
116 name_len = readl(pdev_bus_base + PDEV_BUS_NAME_LEN);
117 if (irq_count)
118 resource_count++;
119
120 dev = kzalloc(sizeof(*dev) +
121 sizeof(struct resource) * resource_count +
122 name_len + 1 + sizeof(*dev->pdev.dev.dma_mask), GFP_ATOMIC);
123 if (dev == NULL)
124 return -ENOMEM;
125
126 dev->pdev.num_resources = resource_count;
127 dev->pdev.resource = (struct resource *)(dev + 1);
128 dev->pdev.name = name = (char *)(dev->pdev.resource + resource_count);
129 dev->pdev.dev.coherent_dma_mask = ~0;
130 dev->pdev.dev.dma_mask = (void *)(dev->pdev.name + name_len + 1);
131 *dev->pdev.dev.dma_mask = ~0;
132
133 #ifdef CONFIG_64BIT
134 writel((u32)((u64)name>>32), pdev_bus_base + PDEV_BUS_GET_NAME_HIGH);
135 #endif
136 writel((u32)(u64)name, pdev_bus_base + PDEV_BUS_GET_NAME);
137 name[name_len] = '\0';
138 dev->pdev.id = readl(pdev_bus_base + PDEV_BUS_ID);
139 dev->pdev.resource[0].start = base;
140 dev->pdev.resource[0].end = base +
141 readl(pdev_bus_base + PDEV_BUS_IO_SIZE) - 1;
142 dev->pdev.resource[0].flags = IORESOURCE_MEM;
143 if (irq_count) {
144 irq = readl(pdev_bus_base + PDEV_BUS_IRQ);
145 dev->pdev.resource[1].start = irq;
146 dev->pdev.resource[1].end = irq + irq_count - 1;
147 dev->pdev.resource[1].flags = IORESOURCE_IRQ;
148 }
149
150 pr_debug("goldfish_new_pdev %s at %x irq %d\n", name, base, irq);
151 list_add_tail(&dev->list, &pdev_bus_new_devices);
152 schedule_work(&pdev_bus_worker);
153
154 return 0;
155 }
156
goldfish_pdev_bus_interrupt(int irq,void * dev_id)157 static irqreturn_t goldfish_pdev_bus_interrupt(int irq, void *dev_id)
158 {
159 irqreturn_t ret = IRQ_NONE;
160 while (1) {
161 u32 op = readl(pdev_bus_base + PDEV_BUS_OP);
162 switch (op) {
163 case PDEV_BUS_OP_DONE:
164 return IRQ_NONE;
165
166 case PDEV_BUS_OP_REMOVE_DEV:
167 goldfish_pdev_remove();
168 break;
169
170 case PDEV_BUS_OP_ADD_DEV:
171 goldfish_new_pdev();
172 break;
173 }
174 ret = IRQ_HANDLED;
175 }
176 return ret;
177 }
178
goldfish_pdev_bus_probe(struct platform_device * pdev)179 static int goldfish_pdev_bus_probe(struct platform_device *pdev)
180 {
181 int ret;
182 struct resource *r;
183
184 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
185 if (r == NULL)
186 return -EINVAL;
187
188 pdev_bus_addr = r->start;
189 pdev_bus_len = resource_size(r);
190
191 pdev_bus_base = ioremap(pdev_bus_addr, pdev_bus_len);
192 if (pdev_bus_base == NULL) {
193 ret = -ENOMEM;
194 dev_err(&pdev->dev, "unable to map Goldfish MMIO.\n");
195 goto free_resources;
196 }
197
198 r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
199 if (r == NULL) {
200 ret = -ENOENT;
201 goto free_map;
202 }
203
204 pdev_bus_irq = r->start;
205
206 ret = request_irq(pdev_bus_irq, goldfish_pdev_bus_interrupt,
207 IRQF_SHARED, "goldfish_pdev_bus", pdev);
208 if (ret) {
209 dev_err(&pdev->dev, "unable to request Goldfish IRQ\n");
210 goto free_map;
211 }
212
213 writel(PDEV_BUS_OP_INIT, pdev_bus_base + PDEV_BUS_OP);
214 return 0;
215
216 free_map:
217 iounmap(pdev_bus_base);
218 free_resources:
219 release_mem_region(pdev_bus_addr, pdev_bus_len);
220 return ret;
221 }
222
goldfish_pdev_bus_remove(struct platform_device * pdev)223 static int goldfish_pdev_bus_remove(struct platform_device *pdev)
224 {
225 iounmap(pdev_bus_base);
226 free_irq(pdev_bus_irq, pdev);
227 release_mem_region(pdev_bus_addr, pdev_bus_len);
228 return 0;
229 }
230
231 static struct platform_driver goldfish_pdev_bus_driver = {
232 .probe = goldfish_pdev_bus_probe,
233 .remove = goldfish_pdev_bus_remove,
234 .driver = {
235 .name = "goldfish_pdev_bus"
236 }
237 };
238
239 module_platform_driver(goldfish_pdev_bus_driver);
240