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
|
/*
* linux/arch/arm/mach-pxa/ssp.c
*
* based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
*
* Copyright (C) 2003 Russell King.
* Copyright (C) 2003 Wolfson Microelectronics PLC
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* PXA2xx SSP driver. This provides the generic core for simple
* IO-based SSP applications and allows easy port setup for DMA access.
*
* Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <plat/ssp.h>
static DEFINE_MUTEX(ssp_lock);
static LIST_HEAD(ssp_list);
struct ssp_device *ssp_request(int port, const char *label)
{
struct ssp_device *ssp = NULL;
mutex_lock(&ssp_lock);
list_for_each_entry(ssp, &ssp_list, node) {
if (ssp->port_id == port && ssp->use_count == 0) {
ssp->use_count++;
ssp->label = label;
break;
}
}
mutex_unlock(&ssp_lock);
if (&ssp->node == &ssp_list)
return NULL;
return ssp;
}
EXPORT_SYMBOL(ssp_request);
void ssp_free(struct ssp_device *ssp)
{
mutex_lock(&ssp_lock);
if (ssp->use_count) {
ssp->use_count--;
ssp->label = NULL;
} else
dev_err(&ssp->pdev->dev, "device already free\n");
mutex_unlock(&ssp_lock);
}
EXPORT_SYMBOL(ssp_free);
static int __devinit ssp_probe(struct platform_device *pdev)
{
const struct platform_device_id *id = platform_get_device_id(pdev);
struct resource *res;
struct ssp_device *ssp;
int ret = 0;
ssp = kzalloc(sizeof(struct ssp_device), GFP_KERNEL);
if (ssp == NULL) {
dev_err(&pdev->dev, "failed to allocate memory");
return -ENOMEM;
}
ssp->pdev = pdev;
ssp->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(ssp->clk)) {
ret = PTR_ERR(ssp->clk);
goto err_free;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL) {
dev_err(&pdev->dev, "no memory resource defined\n");
ret = -ENODEV;
goto err_free_clk;
}
res = request_mem_region(res->start, res->end - res->start + 1,
pdev->name);
if (res == NULL) {
dev_err(&pdev->dev, "failed to request memory resource\n");
ret = -EBUSY;
goto err_free_clk;
}
ssp->phys_base = res->start;
ssp->mmio_base = ioremap(res->start, res->end - res->start + 1);
if (ssp->mmio_base == NULL) {
dev_err(&pdev->dev, "failed to ioremap() registers\n");
ret = -ENODEV;
goto err_free_mem;
}
ssp->irq = platform_get_irq(pdev, 0);
if (ssp->irq < 0) {
dev_err(&pdev->dev, "no IRQ resource defined\n");
ret = -ENODEV;
goto err_free_io;
}
res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
if (res == NULL) {
dev_err(&pdev->dev, "no SSP RX DRCMR defined\n");
ret = -ENODEV;
goto err_free_io;
}
ssp->drcmr_rx = res->start;
res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
if (res == NULL) {
dev_err(&pdev->dev, "no SSP TX DRCMR defined\n");
ret = -ENODEV;
goto err_free_io;
}
ssp->drcmr_tx = res->start;
/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
* starts from 0, do a translation here
*/
ssp->port_id = pdev->id + 1;
ssp->use_count = 0;
ssp->type = (int)id->driver_data;
mutex_lock(&ssp_lock);
list_add(&ssp->node, &ssp_list);
mutex_unlock(&ssp_lock);
platform_set_drvdata(pdev, ssp);
return 0;
err_free_io:
iounmap(ssp->mmio_base);
err_free_mem:
release_mem_region(res->start, res->end - res->start + 1);
err_free_clk:
clk_put(ssp->clk);
err_free:
kfree(ssp);
return ret;
}
static int __devexit ssp_remove(struct platform_device *pdev)
{
struct resource *res;
struct ssp_device *ssp;
ssp = platform_get_drvdata(pdev);
if (ssp == NULL)
return -ENODEV;
iounmap(ssp->mmio_base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(res->start, res->end - res->start + 1);
clk_put(ssp->clk);
mutex_lock(&ssp_lock);
list_del(&ssp->node);
mutex_unlock(&ssp_lock);
kfree(ssp);
return 0;
}
static const struct platform_device_id ssp_id_table[] = {
{ "pxa25x-ssp", PXA25x_SSP },
{ "pxa25x-nssp", PXA25x_NSSP },
{ "pxa27x-ssp", PXA27x_SSP },
{ },
};
static struct platform_driver ssp_driver = {
.probe = ssp_probe,
.remove = __devexit_p(ssp_remove),
.driver = {
.owner = THIS_MODULE,
.name = "pxa2xx-ssp",
},
.id_table = ssp_id_table,
};
static int __init pxa_ssp_init(void)
{
return platform_driver_register(&ssp_driver);
}
static void __exit pxa_ssp_exit(void)
{
platform_driver_unregister(&ssp_driver);
}
arch_initcall(pxa_ssp_init);
module_exit(pxa_ssp_exit);
MODULE_DESCRIPTION("PXA SSP driver");
MODULE_AUTHOR("Liam Girdwood");
MODULE_LICENSE("GPL");
|
