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
111 dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
112
113 for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
114 fault <<= 8;
115 fault |= ((unsigned long)buff[ptr]);
116
117 dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
118 }
119
120 for (ptr = 0; ptr < st->nr_gpio; ptr++) {
121 bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
122 }
123
124 *bp++ = '\n';
125
126 mutex_unlock(&st->lock);
127 return bp - buf;
128}
129
130static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
131
132static ssize_t tle62x0_gpio_show(struct device *dev,
133 struct device_attribute *attr, char *buf)
134{
135 struct tle62x0_state *st = dev_get_drvdata(dev);
136 int gpio_num = to_gpio_num(attr);
137 int value;
138
139 mutex_lock(&st->lock);
140 value = (st->gpio_state >> gpio_num) & 1;
141 mutex_unlock(&st->lock);
142
143 return snprintf(buf, PAGE_SIZE, "%d", value);
144}
145
146static ssize_t tle62x0_gpio_store(struct device *dev,
147 struct device_attribute *attr,
148 const char *buf, size_t len)
149{
150 struct tle62x0_state *st = dev_get_drvdata(dev);
151 int gpio_num = to_gpio_num(attr);
152 unsigned long val;
153 char *endp;
154
155 val = simple_strtoul(buf, &endp, 0);
156 if (buf == endp)
157 return -EINVAL;
158
159 dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
160
161 mutex_lock(&st->lock);
162
163 if (val)
164 st->gpio_state |= 1 << gpio_num;
165 else
166 st->gpio_state &= ~(1 << gpio_num);
167
168 tle62x0_write(st);
169 mutex_unlock(&st->lock);
170
171 return len;
172}
173
174static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
175 tle62x0_gpio_show, tle62x0_gpio_store);
176static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
177 tle62x0_gpio_show, tle62x0_gpio_store);
178static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
179 tle62x0_gpio_show, tle62x0_gpio_store);
180static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
181 tle62x0_gpio_show, tle62x0_gpio_store);
182static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
183 tle62x0_gpio_show, tle62x0_gpio_store);
184static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
185 tle62x0_gpio_show, tle62x0_gpio_store);
186static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
187 tle62x0_gpio_show, tle62x0_gpio_store);
188static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
189 tle62x0_gpio_show, tle62x0_gpio_store);
190static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
191 tle62x0_gpio_show, tle62x0_gpio_store);
192static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
193 tle62x0_gpio_show, tle62x0_gpio_store);
194static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
195 tle62x0_gpio_show, tle62x0_gpio_store);
196static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
197 tle62x0_gpio_show, tle62x0_gpio_store);
198static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
199 tle62x0_gpio_show, tle62x0_gpio_store);
200static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
201 tle62x0_gpio_show, tle62x0_gpio_store);
202static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
203 tle62x0_gpio_show, tle62x0_gpio_store);
204static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
205 tle62x0_gpio_show, tle62x0_gpio_store);
206
207static struct device_attribute *gpio_attrs[] = {
208 [0] = &dev_attr_gpio1,
209 [1] = &dev_attr_gpio2,
210 [2] = &dev_attr_gpio3,
211 [3] = &dev_attr_gpio4,
212 [4] = &dev_attr_gpio5,
213 [5] = &dev_attr_gpio6,
214 [6] = &dev_attr_gpio7,
215 [7] = &dev_attr_gpio8,
216 [8] = &dev_attr_gpio9,
217 [9] = &dev_attr_gpio10,
218 [10] = &dev_attr_gpio11,
219 [11] = &dev_attr_gpio12,
220 [12] = &dev_attr_gpio13,
221 [13] = &dev_attr_gpio14,
222 [14] = &dev_attr_gpio15,
223 [15] = &dev_attr_gpio16
224};
225
226static int to_gpio_num(struct device_attribute *attr)
227{
228 int ptr;
229
230 for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
231 if (gpio_attrs[ptr] == attr)
232 return ptr;
233 }
234
235 return -1;
236}
237
238static int __devinit tle62x0_probe(struct spi_device *spi)
239{
240 struct tle62x0_state *st;
241 struct tle62x0_pdata *pdata;
242 int ptr;
243 int ret;
244
245 pdata = spi->dev.platform_data;
246 if (pdata == NULL) {
247 dev_err(&spi->dev, "no device data specified\n");
248 return -EINVAL;
249 }
250
251 st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
252 if (st == NULL) {
253 dev_err(&spi->dev, "no memory for device state\n");
254 return -ENOMEM;
255 }
256
257 st->us = spi;
258 st->nr_gpio = pdata->gpio_count;
259 st->gpio_state = pdata->init_state;
260
261 mutex_init(&st->lock);
262
263 ret = device_create_file(&spi->dev, &dev_attr_status_show);
264 if (ret) {
265 dev_err(&spi->dev, "cannot create status attribute\n");
266 goto err_status;
267 }
268
269 for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
270 ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
271 if (ret) {
272 dev_err(&spi->dev, "cannot create gpio attribute\n");
273 goto err_gpios;
274 }
275 }
276
277 /* tle62x0_write(st); */
278 spi_set_drvdata(spi, st);
279 return 0;
280
281 err_gpios:
282 for (; ptr > 0; ptr--)
283 device_remove_file(&spi->dev, gpio_attrs[ptr]);
284
285 device_remove_file(&spi->dev, &dev_attr_status_show);
286
287 err_status:
288 kfree(st);
289 return ret;
290}
291
292static int __devexit tle62x0_remove(struct spi_device *spi)
293{
294 struct tle62x0_state *st = spi_get_drvdata(spi);
295 int ptr;
296
297 for (ptr = 0; ptr < st->nr_gpio; ptr++)
298 device_remove_file(&spi->dev, gpio_attrs[ptr]);
299
300 kfree(st);
301 return 0;
302}
303
304static struct spi_driver tle62x0_driver = {
305 .driver = {
306 .name = "tle62x0",
307 .owner = THIS_MODULE,
308 },
309 .probe = tle62x0_probe,
310 .remove = __devexit_p(tle62x0_remove),
311};
312
313static __init int tle62x0_init(void)
314{
315 return spi_register_driver(&tle62x0_driver);
316}
317
318static __exit void tle62x0_exit(void)
319{
320 spi_unregister_driver(&tle62x0_driver);
321}
322
323module_init(tle62x0_init);
324module_exit(tle62x0_exit);
325
326MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
327MODULE_DESCRIPTION("TLE62x0 SPI driver");
328MODULE_LICENSE("GPL v2");