tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * tle62x0.c -- support Infineon TLE62x0 driver chips
3 *
4 * Copyright (c) 2007 Simtec Electronics
5 * Ben Dooks, <ben@simtec.co.uk>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/device.h>
13#include <linux/kernel.h>
14
15#include <linux/spi/spi.h>
16#include <linux/spi/tle62x0.h>
17
18
19#define CMD_READ 0x00
20#define CMD_SET 0xff
21
22#define DIAG_NORMAL 0x03
23#define DIAG_OVERLOAD 0x02
24#define DIAG_OPEN 0x01
25#define DIAG_SHORTGND 0x00
26
27struct tle62x0_state {
28 struct spi_device *us;
29 struct mutex lock;
30 unsigned int nr_gpio;
31 unsigned int gpio_state;
32
33 unsigned char tx_buff[4];
34 unsigned char rx_buff[4];
35};
36
37static int to_gpio_num(struct device_attribute *attr);
38
39static inline int tle62x0_write(struct tle62x0_state *st)
40{
41 unsigned char *buff = st->tx_buff;
42 unsigned int gpio_state = st->gpio_state;
43
44 buff[0] = CMD_SET;
45
46 if (st->nr_gpio == 16) {
47 buff[1] = gpio_state >> 8;
48 buff[2] = gpio_state;
49 } else {
50 buff[1] = gpio_state;
51 }
52
53 dev_dbg(&st->us->dev, "buff %02x,%02x,%02x\n",
54 buff[0], buff[1], buff[2]);
55
56 return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);
57}
58
59static inline int tle62x0_read(struct tle62x0_state *st)
60{
61 unsigned char *txbuff = st->tx_buff;
62 struct spi_transfer xfer = {
63 .tx_buf = txbuff,
64 .rx_buf = st->rx_buff,
65 .len = (st->nr_gpio * 2) / 8,
66 };
67 struct spi_message msg;
68
69 txbuff[0] = CMD_READ;
70 txbuff[1] = 0x00;
71 txbuff[2] = 0x00;
72 txbuff[3] = 0x00;
73
74 spi_message_init(&msg);
75 spi_message_add_tail(&xfer, &msg);
76
77 return spi_sync(st->us, &msg);
78}
79
80static unsigned char *decode_fault(unsigned int fault_code)
81{
82 fault_code &= 3;
83
84 switch (fault_code) {
85 case DIAG_NORMAL:
86 return "N";
87 case DIAG_OVERLOAD:
88 return "V";
89 case DIAG_OPEN:
90 return "O";
91 case DIAG_SHORTGND:
92 return "G";
93 }
94
95 return "?";
96}
97
98static ssize_t tle62x0_status_show(struct device *dev,
99 struct device_attribute *attr, char *buf)
100{
101 struct tle62x0_state *st = dev_get_drvdata(dev);
102 char *bp = buf;
103 unsigned char *buff = st->rx_buff;
104 unsigned long fault = 0;
105 int ptr;
106 int ret;
107
108 mutex_lock(&st->lock);
109 ret = tle62x0_read(st);
110 dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
111 if (ret < 0) {
112 mutex_unlock(&st->lock);
113 return ret;
114 }
115
116 for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
117 fault <<= 8;
118 fault |= ((unsigned long)buff[ptr]);
119
120 dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
121 }
122
123 for (ptr = 0; ptr < st->nr_gpio; ptr++) {
124 bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
125 }
126
127 *bp++ = '\n';
128
129 mutex_unlock(&st->lock);
130 return bp - buf;
131}
132
133static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
134
135static ssize_t tle62x0_gpio_show(struct device *dev,
136 struct device_attribute *attr, char *buf)
137{
138 struct tle62x0_state *st = dev_get_drvdata(dev);
139 int gpio_num = to_gpio_num(attr);
140 int value;
141
142 mutex_lock(&st->lock);
143 value = (st->gpio_state >> gpio_num) & 1;
144 mutex_unlock(&st->lock);
145
146 return snprintf(buf, PAGE_SIZE, "%d", value);
147}
148
149static ssize_t tle62x0_gpio_store(struct device *dev,
150 struct device_attribute *attr,
151 const char *buf, size_t len)
152{
153 struct tle62x0_state *st = dev_get_drvdata(dev);
154 int gpio_num = to_gpio_num(attr);
155 unsigned long val;
156 char *endp;
157
158 val = simple_strtoul(buf, &endp, 0);
159 if (buf == endp)
160 return -EINVAL;
161
162 dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
163
164 mutex_lock(&st->lock);
165
166 if (val)
167 st->gpio_state |= 1 << gpio_num;
168 else
169 st->gpio_state &= ~(1 << gpio_num);
170
171 tle62x0_write(st);
172 mutex_unlock(&st->lock);
173
174 return len;
175}
176
177static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
178 tle62x0_gpio_show, tle62x0_gpio_store);
179static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
180 tle62x0_gpio_show, tle62x0_gpio_store);
181static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
182 tle62x0_gpio_show, tle62x0_gpio_store);
183static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
184 tle62x0_gpio_show, tle62x0_gpio_store);
185static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
186 tle62x0_gpio_show, tle62x0_gpio_store);
187static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
188 tle62x0_gpio_show, tle62x0_gpio_store);
189static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
190 tle62x0_gpio_show, tle62x0_gpio_store);
191static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
192 tle62x0_gpio_show, tle62x0_gpio_store);
193static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
194 tle62x0_gpio_show, tle62x0_gpio_store);
195static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
196 tle62x0_gpio_show, tle62x0_gpio_store);
197static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
198 tle62x0_gpio_show, tle62x0_gpio_store);
199static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
200 tle62x0_gpio_show, tle62x0_gpio_store);
201static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
202 tle62x0_gpio_show, tle62x0_gpio_store);
203static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
204 tle62x0_gpio_show, tle62x0_gpio_store);
205static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
206 tle62x0_gpio_show, tle62x0_gpio_store);
207static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
208 tle62x0_gpio_show, tle62x0_gpio_store);
209
210static struct device_attribute *gpio_attrs[] = {
211 [0] = &dev_attr_gpio1,
212 [1] = &dev_attr_gpio2,
213 [2] = &dev_attr_gpio3,
214 [3] = &dev_attr_gpio4,
215 [4] = &dev_attr_gpio5,
216 [5] = &dev_attr_gpio6,
217 [6] = &dev_attr_gpio7,
218 [7] = &dev_attr_gpio8,
219 [8] = &dev_attr_gpio9,
220 [9] = &dev_attr_gpio10,
221 [10] = &dev_attr_gpio11,
222 [11] = &dev_attr_gpio12,
223 [12] = &dev_attr_gpio13,
224 [13] = &dev_attr_gpio14,
225 [14] = &dev_attr_gpio15,
226 [15] = &dev_attr_gpio16
227};
228
229static int to_gpio_num(struct device_attribute *attr)
230{
231 int ptr;
232
233 for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
234 if (gpio_attrs[ptr] == attr)
235 return ptr;
236 }
237
238 return -1;
239}
240
241static int __devinit tle62x0_probe(struct spi_device *spi)
242{
243 struct tle62x0_state *st;
244 struct tle62x0_pdata *pdata;
245 int ptr;
246 int ret;
247
248 pdata = spi->dev.platform_data;
249 if (pdata == NULL) {
250 dev_err(&spi->dev, "no device data specified\n");
251 return -EINVAL;
252 }
253
254 st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
255 if (st == NULL) {
256 dev_err(&spi->dev, "no memory for device state\n");
257 return -ENOMEM;
258 }
259
260 st->us = spi;
261 st->nr_gpio = pdata->gpio_count;
262 st->gpio_state = pdata->init_state;
263
264 mutex_init(&st->lock);
265
266 ret = device_create_file(&spi->dev, &dev_attr_status_show);
267 if (ret) {
268 dev_err(&spi->dev, "cannot create status attribute\n");
269 goto err_status;
270 }
271
272 for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
273 ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
274 if (ret) {
275 dev_err(&spi->dev, "cannot create gpio attribute\n");
276 goto err_gpios;
277 }
278 }
279
280 /* tle62x0_write(st); */
281 spi_set_drvdata(spi, st);
282 return 0;
283
284 err_gpios:
285 for (; ptr > 0; ptr--)
286 device_remove_file(&spi->dev, gpio_attrs[ptr]);
287
288 device_remove_file(&spi->dev, &dev_attr_status_show);
289
290 err_status:
291 kfree(st);
292 return ret;
293}
294
295static int __devexit tle62x0_remove(struct spi_device *spi)
296{
297 struct tle62x0_state *st = spi_get_drvdata(spi);
298 int ptr;
299
300 for (ptr = 0; ptr < st->nr_gpio; ptr++)
301 device_remove_file(&spi->dev, gpio_attrs[ptr]);
302
303 kfree(st);
304 return 0;
305}
306
307static struct spi_driver tle62x0_driver = {
308 .driver = {
309 .name = "tle62x0",
310 .owner = THIS_MODULE,
311 },
312 .probe = tle62x0_probe,
313 .remove = __devexit_p(tle62x0_remove),
314};
315
316static __init int tle62x0_init(void)
317{
318 return spi_register_driver(&tle62x0_driver);
319}
320
321static __exit void tle62x0_exit(void)
322{
323 spi_unregister_driver(&tle62x0_driver);
324}
325
326module_init(tle62x0_init);
327module_exit(tle62x0_exit);
328
329MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
330MODULE_DESCRIPTION("TLE62x0 SPI driver");
331MODULE_LICENSE("GPL v2");