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