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