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
|
/* Philips PCF50606 ADC Driver
*
* (C) 2006-2008 by Openmoko, Inc.
* Author: Balaji Rao <balajirrao@openmoko.org>
* All rights reserved.
*
* Broken down from monstrous PCF50606 driver mainly by
* Harald Welte, Andy Green and Werner Almesberger
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <linux/mfd/pcf50606/core.h>
#include <linux/mfd/pcf50606/adc.h>
struct pcf50606_adc_request {
int mux;
int avg;
int result;
void (*callback)(struct pcf50606 *, void *, int);
void *callback_param;
/* Used in case of sync requests */
struct completion completion;
};
static void adc_read_setup(struct pcf50606 *pcf,
int channel, int avg)
{
channel &= PCF50606_ADCC2_ADCMUX_MASK;
/* start ADC conversion of selected channel */
pcf50606_reg_write(pcf, PCF50606_REG_ADCC2, channel |
PCF50606_ADCC2_ADCSTART | PCF50606_ADCC2_RES_10BIT);
}
static void trigger_next_adc_job_if_any(struct pcf50606 *pcf)
{
int head, tail;
mutex_lock(&pcf->adc.queue_mutex);
head = pcf->adc.queue_head;
tail = pcf->adc.queue_tail;
if (!pcf->adc.queue[head])
goto out;
adc_read_setup(pcf, pcf->adc.queue[head]->mux,
pcf->adc.queue[head]->avg);
out:
mutex_unlock(&pcf->adc.queue_mutex);
}
static int
adc_enqueue_request(struct pcf50606 *pcf, struct pcf50606_adc_request *req)
{
int head, tail;
mutex_lock(&pcf->adc.queue_mutex);
head = pcf->adc.queue_head;
tail = pcf->adc.queue_tail;
if (pcf->adc.queue[tail]) {
mutex_unlock(&pcf->adc.queue_mutex);
return -EBUSY;
}
pcf->adc.queue[tail] = req;
pcf->adc.queue_tail =
(tail + 1) & (PCF50606_MAX_ADC_FIFO_DEPTH - 1);
mutex_unlock(&pcf->adc.queue_mutex);
trigger_next_adc_job_if_any(pcf);
return 0;
}
static void
pcf50606_adc_sync_read_callback(struct pcf50606 *pcf, void *param, int result)
{
struct pcf50606_adc_request *req;
/*We know here that the passed param is an adc_request object */
req = (struct pcf50606_adc_request *)param;
req->result = result;
complete(&req->completion);
}
int pcf50606_adc_sync_read(struct pcf50606 *pcf, int mux, int avg)
{
struct pcf50606_adc_request *req;
int result;
/* req is freed when the result is ready, in pcf50606_work*/
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
req->mux = mux;
req->avg = avg;
req->callback = pcf50606_adc_sync_read_callback;
req->callback_param = req;
init_completion(&req->completion);
adc_enqueue_request(pcf, req);
wait_for_completion(&req->completion);
result = req->result;
return result;
}
EXPORT_SYMBOL_GPL(pcf50606_adc_sync_read);
int pcf50606_adc_async_read(struct pcf50606 *pcf, int mux, int avg,
void (*callback)(struct pcf50606 *, void *, int),
void *callback_param)
{
struct pcf50606_adc_request *req;
/* req is freed when the result is ready, in pcf50606_work*/
req = kmalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
req->mux = mux;
req->avg = avg;
req->callback = callback;
req->callback_param = callback_param;
adc_enqueue_request(pcf, req);
return 0;
}
EXPORT_SYMBOL_GPL(pcf50606_adc_async_read);
static int adc_result(struct pcf50606 *pcf)
{
u16 ret = (pcf50606_reg_read(pcf, PCF50606_REG_ADCS1) << 2) |
(pcf50606_reg_read(pcf, PCF50606_REG_ADCS2) & 0x03);
dev_info(pcf->dev, "adc result = %d\n", ret);
return ret;
}
static void pcf50606_adc_irq(struct pcf50606 *pcf, int irq, void *unused)
{
struct pcf50606_adc_request *req;
int head;
mutex_lock(&pcf->adc.queue_mutex);
head = pcf->adc.queue_head;
req = pcf->adc.queue[head];
if (!req) {
dev_err(pcf->dev, "ADC queue empty\n");
mutex_unlock(&pcf->adc.queue_mutex);
return;
}
pcf->adc.queue[head] = NULL;
pcf->adc.queue_head = (head + 1) &
(PCF50606_MAX_ADC_FIFO_DEPTH - 1);
mutex_unlock(&pcf->adc.queue_mutex);
req->callback(pcf, req->callback_param, adc_result(pcf));
kfree(req);
trigger_next_adc_job_if_any(pcf);
}
int __init pcf50606_adc_probe(struct platform_device *pdev)
{
struct pcf50606 *pcf;
pcf = platform_get_drvdata(pdev);
/* Set up IRQ handlers */
pcf->irq_handler[PCF50606_IRQ_ADCRDY].handler = pcf50606_adc_irq;
mutex_init(&pcf->adc.queue_mutex);
return 0;
}
static int __devexit pcf50606_adc_remove(struct platform_device *pdev)
{
struct pcf50606 *pcf;
pcf = platform_get_drvdata(pdev);
pcf->irq_handler[PCF50606_IRQ_ADCRDY].handler = NULL;
return 0;
}
struct platform_driver pcf50606_adc_driver = {
.driver = {
.name = "pcf50606-adc",
},
.probe = pcf50606_adc_probe,
.remove = __devexit_p(pcf50606_adc_remove),
};
static int __init pcf50606_adc_init(void)
{
return platform_driver_register(&pcf50606_adc_driver);
}
module_init(pcf50606_adc_init);
static void __exit pcf50606_adc_exit(void)
{
platform_driver_unregister(&pcf50606_adc_driver);
}
module_exit(pcf50606_adc_exit);
MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
MODULE_DESCRIPTION("PCF50606 adc driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcf50606-adc");
|
