summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/platform/goldfish/pdev_bus.c
blob: 8c43589c3edba9248c13760c8e92025b4a5cf599 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
/*
 * Copyright (C) 2007 Google, Inc.
 * Copyright (C) 2011 Intel, Inc.
 * Copyright (C) 2013 Intel, Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/io.h>

#define PDEV_BUS_OP_DONE        (0x00)
#define PDEV_BUS_OP_REMOVE_DEV  (0x04)
#define PDEV_BUS_OP_ADD_DEV     (0x08)

#define PDEV_BUS_OP_INIT        (0x00)

#define PDEV_BUS_OP             (0x00)
#define PDEV_BUS_GET_NAME       (0x04)
#define PDEV_BUS_NAME_LEN       (0x08)
#define PDEV_BUS_ID             (0x0c)
#define PDEV_BUS_IO_BASE        (0x10)
#define PDEV_BUS_IO_SIZE        (0x14)
#define PDEV_BUS_IRQ            (0x18)
#define PDEV_BUS_IRQ_COUNT      (0x1c)
#define PDEV_BUS_GET_NAME_HIGH  (0x20)

struct pdev_bus_dev {
	struct list_head list;
	struct platform_device pdev;
	struct resource resources[0];
};

static void goldfish_pdev_worker(struct work_struct *work);

static void __iomem *pdev_bus_base;
static unsigned long pdev_bus_addr;
static unsigned long pdev_bus_len;
static u32 pdev_bus_irq;
static LIST_HEAD(pdev_bus_new_devices);
static LIST_HEAD(pdev_bus_registered_devices);
static LIST_HEAD(pdev_bus_removed_devices);
static DECLARE_WORK(pdev_bus_worker, goldfish_pdev_worker);


static void goldfish_pdev_worker(struct work_struct *work)
{
	int ret;
	struct pdev_bus_dev *pos, *n;

	list_for_each_entry_safe(pos, n, &pdev_bus_removed_devices, list) {
		list_del(&pos->list);
		platform_device_unregister(&pos->pdev);
		kfree(pos);
	}
	list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
		list_del(&pos->list);
		ret = platform_device_register(&pos->pdev);
		if (ret)
			pr_err("goldfish_pdev_worker failed to register device, %s\n",
								pos->pdev.name);
		list_add_tail(&pos->list, &pdev_bus_registered_devices);
	}
}

static void goldfish_pdev_remove(void)
{
	struct pdev_bus_dev *pos, *n;
	u32 base;

	base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);

	list_for_each_entry_safe(pos, n, &pdev_bus_new_devices, list) {
		if (pos->resources[0].start == base) {
			list_del(&pos->list);
			kfree(pos);
			return;
		}
	}
	list_for_each_entry_safe(pos, n, &pdev_bus_registered_devices, list) {
		if (pos->resources[0].start == base) {
			list_del(&pos->list);
			list_add_tail(&pos->list, &pdev_bus_removed_devices);
			schedule_work(&pdev_bus_worker);
			return;
		}
	};
	pr_err("goldfish_pdev_remove could not find device at %x\n", base);
}

static int goldfish_new_pdev(void)
{
	struct pdev_bus_dev *dev;
	u32 name_len;
	u32 irq = -1, irq_count;
	int resource_count = 2;
	u32 base;
	char *name;

	base = readl(pdev_bus_base + PDEV_BUS_IO_BASE);

	irq_count = readl(pdev_bus_base + PDEV_BUS_IRQ_COUNT);
	name_len = readl(pdev_bus_base + PDEV_BUS_NAME_LEN);
	if (irq_count)
		resource_count++;

	dev = kzalloc(sizeof(*dev) +
		sizeof(struct resource) * resource_count +
		name_len + 1 + sizeof(*dev->pdev.dev.dma_mask), GFP_ATOMIC);
	if (dev == NULL)
		return -ENOMEM;

	dev->pdev.num_resources = resource_count;
	dev->pdev.resource = (struct resource *)(dev + 1);
	dev->pdev.name = name = (char *)(dev->pdev.resource + resource_count);
	dev->pdev.dev.coherent_dma_mask = ~0;
	dev->pdev.dev.dma_mask = (void *)(dev->pdev.name + name_len + 1);
	*dev->pdev.dev.dma_mask = ~0;

#ifdef CONFIG_64BIT
	writel((u32)((u64)name>>32), pdev_bus_base + PDEV_BUS_GET_NAME_HIGH);
#endif
	writel((u32)(unsigned long)name, pdev_bus_base + PDEV_BUS_GET_NAME);
	name[name_len] = '\0';
	dev->pdev.id = readl(pdev_bus_base + PDEV_BUS_ID);
	dev->pdev.resource[0].start = base;
	dev->pdev.resource[0].end = base +
				readl(pdev_bus_base + PDEV_BUS_IO_SIZE) - 1;
	dev->pdev.resource[0].flags = IORESOURCE_MEM;
	if (irq_count) {
		irq = readl(pdev_bus_base + PDEV_BUS_IRQ);
		dev->pdev.resource[1].start = irq;
		dev->pdev.resource[1].end = irq + irq_count - 1;
		dev->pdev.resource[1].flags = IORESOURCE_IRQ;
	}

	pr_debug("goldfish_new_pdev %s at %x irq %d\n", name, base, irq);
	list_add_tail(&dev->list, &pdev_bus_new_devices);
	schedule_work(&pdev_bus_worker);

	return 0;
}

static irqreturn_t goldfish_pdev_bus_interrupt(int irq, void *dev_id)
{
	irqreturn_t ret = IRQ_NONE;
	while (1) {
		u32 op = readl(pdev_bus_base + PDEV_BUS_OP);
		switch (op) {
		case PDEV_BUS_OP_DONE:
			return IRQ_NONE;

		case PDEV_BUS_OP_REMOVE_DEV:
			goldfish_pdev_remove();
			break;

		case PDEV_BUS_OP_ADD_DEV:
			goldfish_new_pdev();
			break;
		}
		ret = IRQ_HANDLED;
	}
	return ret;
}

static int goldfish_pdev_bus_probe(struct platform_device *pdev)
{
	int ret;
	struct resource *r;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (r == NULL)
		return -EINVAL;

	pdev_bus_addr = r->start;
	pdev_bus_len = resource_size(r);

	pdev_bus_base = ioremap(pdev_bus_addr, pdev_bus_len);
	if (pdev_bus_base == NULL) {
		ret = -ENOMEM;
		dev_err(&pdev->dev, "unable to map Goldfish MMIO.\n");
		goto free_resources;
	}

	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (r == NULL) {
		ret = -ENOENT;
		goto free_map;
	}

	pdev_bus_irq = r->start;

	ret = request_irq(pdev_bus_irq, goldfish_pdev_bus_interrupt,
				IRQF_SHARED, "goldfish_pdev_bus", pdev);
	if (ret) {
		dev_err(&pdev->dev, "unable to request Goldfish IRQ\n");
		goto free_map;
	}

	writel(PDEV_BUS_OP_INIT, pdev_bus_base + PDEV_BUS_OP);
	return 0;

free_map:
	iounmap(pdev_bus_base);
free_resources:
	release_mem_region(pdev_bus_addr, pdev_bus_len);
	return ret;
}

static int goldfish_pdev_bus_remove(struct platform_device *pdev)
{
	iounmap(pdev_bus_base);
	free_irq(pdev_bus_irq, pdev);
	release_mem_region(pdev_bus_addr, pdev_bus_len);
	return 0;
}

static struct platform_driver goldfish_pdev_bus_driver = {
	.probe = goldfish_pdev_bus_probe,
	.remove = goldfish_pdev_bus_remove,
	.driver = {
		.name = "goldfish_pdev_bus"
	}
};

module_platform_driver(goldfish_pdev_bus_driver);