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10#include <linux/kernel.h>
11#include <linux/errno.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/types.h>
15#include <linux/mutex.h>
16#include <linux/platform_device.h>
17
18#include <linux/usb.h>
19#include <linux/i2c.h>
20
21#include <linux/mfd/viperboard.h>
22
23struct vprbrd_i2c {
24 struct i2c_adapter i2c;
25 u8 bus_freq_param;
26};
27
28
29static u8 i2c_bus_param;
30static unsigned int i2c_bus_freq = 100;
31module_param(i2c_bus_freq, int, 0);
32MODULE_PARM_DESC(i2c_bus_freq,
33 "i2c bus frequency in khz (default is 100) valid values: 10, 100, 200, 400, 1000, 3000, 6000");
34
35static int vprbrd_i2c_status(struct i2c_adapter *i2c,
36 struct vprbrd_i2c_status *status, bool prev_error)
37{
38 u16 bytes_xfer;
39 int ret;
40 struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
41
42
43 bytes_xfer = sizeof(struct vprbrd_i2c_status);
44
45 ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
46 VPRBRD_USB_REQUEST_I2C, VPRBRD_USB_TYPE_IN, 0x0000, 0x0000,
47 status, bytes_xfer, VPRBRD_USB_TIMEOUT_MS);
48
49 if (ret != bytes_xfer)
50 prev_error = true;
51
52 if (prev_error) {
53 dev_err(&i2c->dev, "failure in usb communication\n");
54 return -EREMOTEIO;
55 }
56
57 dev_dbg(&i2c->dev, " status = %d\n", status->status);
58 if (status->status != 0x00) {
59 dev_err(&i2c->dev, "failure: i2c protocol error\n");
60 return -EPROTO;
61 }
62 return 0;
63}
64
65static int vprbrd_i2c_receive(struct usb_device *usb_dev,
66 struct vprbrd_i2c_read_msg *rmsg, int bytes_xfer)
67{
68 int ret, bytes_actual;
69 int error = 0;
70
71
72 ret = usb_bulk_msg(usb_dev,
73 usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), rmsg,
74 sizeof(struct vprbrd_i2c_read_hdr), &bytes_actual,
75 VPRBRD_USB_TIMEOUT_MS);
76
77 if ((ret < 0)
78 || (bytes_actual != sizeof(struct vprbrd_i2c_read_hdr))) {
79 dev_err(&usb_dev->dev, "failure transmitting usb\n");
80 error = -EREMOTEIO;
81 }
82
83
84 ret = usb_bulk_msg(usb_dev,
85 usb_rcvbulkpipe(usb_dev, VPRBRD_EP_IN), rmsg,
86 bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
87
88 if ((ret < 0) || (bytes_xfer != bytes_actual)) {
89 dev_err(&usb_dev->dev, "failure receiving usb\n");
90 error = -EREMOTEIO;
91 }
92 return error;
93}
94
95static int vprbrd_i2c_addr(struct usb_device *usb_dev,
96 struct vprbrd_i2c_addr_msg *amsg)
97{
98 int ret, bytes_actual;
99
100 ret = usb_bulk_msg(usb_dev,
101 usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), amsg,
102 sizeof(struct vprbrd_i2c_addr_msg), &bytes_actual,
103 VPRBRD_USB_TIMEOUT_MS);
104
105 if ((ret < 0) ||
106 (sizeof(struct vprbrd_i2c_addr_msg) != bytes_actual)) {
107 dev_err(&usb_dev->dev, "failure transmitting usb\n");
108 return -EREMOTEIO;
109 }
110 return 0;
111}
112
113static int vprbrd_i2c_read(struct vprbrd *vb, struct i2c_msg *msg)
114{
115 int ret;
116 u16 remain_len, len1, len2, start = 0x0000;
117 struct vprbrd_i2c_read_msg *rmsg =
118 (struct vprbrd_i2c_read_msg *)vb->buf;
119
120 remain_len = msg->len;
121 rmsg->header.cmd = VPRBRD_I2C_CMD_READ;
122 while (remain_len > 0) {
123 rmsg->header.addr = cpu_to_le16(start + 0x4000);
124 if (remain_len <= 255) {
125 len1 = remain_len;
126 len2 = 0x00;
127 rmsg->header.len0 = remain_len;
128 rmsg->header.len1 = 0x00;
129 rmsg->header.len2 = 0x00;
130 rmsg->header.len3 = 0x00;
131 rmsg->header.len4 = 0x00;
132 rmsg->header.len5 = 0x00;
133 remain_len = 0;
134 } else if (remain_len <= 510) {
135 len1 = remain_len;
136 len2 = 0x00;
137 rmsg->header.len0 = remain_len - 255;
138 rmsg->header.len1 = 0xff;
139 rmsg->header.len2 = 0x00;
140 rmsg->header.len3 = 0x00;
141 rmsg->header.len4 = 0x00;
142 rmsg->header.len5 = 0x00;
143 remain_len = 0;
144 } else if (remain_len <= 512) {
145 len1 = remain_len;
146 len2 = 0x00;
147 rmsg->header.len0 = remain_len - 510;
148 rmsg->header.len1 = 0xff;
149 rmsg->header.len2 = 0xff;
150 rmsg->header.len3 = 0x00;
151 rmsg->header.len4 = 0x00;
152 rmsg->header.len5 = 0x00;
153 remain_len = 0;
154 } else if (remain_len <= 767) {
155 len1 = 512;
156 len2 = remain_len - 512;
157 rmsg->header.len0 = 0x02;
158 rmsg->header.len1 = 0xff;
159 rmsg->header.len2 = 0xff;
160 rmsg->header.len3 = remain_len - 512;
161 rmsg->header.len4 = 0x00;
162 rmsg->header.len5 = 0x00;
163 remain_len = 0;
164 } else if (remain_len <= 1022) {
165 len1 = 512;
166 len2 = remain_len - 512;
167 rmsg->header.len0 = 0x02;
168 rmsg->header.len1 = 0xff;
169 rmsg->header.len2 = 0xff;
170 rmsg->header.len3 = remain_len - 767;
171 rmsg->header.len4 = 0xff;
172 rmsg->header.len5 = 0x00;
173 remain_len = 0;
174 } else if (remain_len <= 1024) {
175 len1 = 512;
176 len2 = remain_len - 512;
177 rmsg->header.len0 = 0x02;
178 rmsg->header.len1 = 0xff;
179 rmsg->header.len2 = 0xff;
180 rmsg->header.len3 = remain_len - 1022;
181 rmsg->header.len4 = 0xff;
182 rmsg->header.len5 = 0xff;
183 remain_len = 0;
184 } else {
185 len1 = 512;
186 len2 = 512;
187 rmsg->header.len0 = 0x02;
188 rmsg->header.len1 = 0xff;
189 rmsg->header.len2 = 0xff;
190 rmsg->header.len3 = 0x02;
191 rmsg->header.len4 = 0xff;
192 rmsg->header.len5 = 0xff;
193 remain_len -= 1024;
194 start += 1024;
195 }
196 rmsg->header.tf1 = cpu_to_le16(len1);
197 rmsg->header.tf2 = cpu_to_le16(len2);
198
199
200 ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len1);
201 if (ret < 0)
202 return ret;
203
204 memcpy(msg->buf + start, rmsg, len1);
205
206
207 if (len2 > 0) {
208 ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len2);
209 if (ret < 0)
210 return ret;
211
212 memcpy(msg->buf + start + 512, rmsg, len2);
213 }
214 }
215 return 0;
216}
217
218static int vprbrd_i2c_write(struct vprbrd *vb, struct i2c_msg *msg)
219{
220 int ret, bytes_actual;
221 u16 remain_len, bytes_xfer,
222 start = 0x0000;
223 struct vprbrd_i2c_write_msg *wmsg =
224 (struct vprbrd_i2c_write_msg *)vb->buf;
225
226 remain_len = msg->len;
227 wmsg->header.cmd = VPRBRD_I2C_CMD_WRITE;
228 wmsg->header.last = 0x00;
229 wmsg->header.chan = 0x00;
230 wmsg->header.spi = 0x0000;
231 while (remain_len > 0) {
232 wmsg->header.addr = cpu_to_le16(start + 0x4000);
233 if (remain_len > 503) {
234 wmsg->header.len1 = 0xff;
235 wmsg->header.len2 = 0xf8;
236 remain_len -= 503;
237 bytes_xfer = 503 + sizeof(struct vprbrd_i2c_write_hdr);
238 start += 503;
239 } else if (remain_len > 255) {
240 wmsg->header.len1 = 0xff;
241 wmsg->header.len2 = (remain_len - 255);
242 bytes_xfer = remain_len +
243 sizeof(struct vprbrd_i2c_write_hdr);
244 remain_len = 0;
245 } else {
246 wmsg->header.len1 = remain_len;
247 wmsg->header.len2 = 0x00;
248 bytes_xfer = remain_len +
249 sizeof(struct vprbrd_i2c_write_hdr);
250 remain_len = 0;
251 }
252 memcpy(wmsg->data, msg->buf + start,
253 bytes_xfer - sizeof(struct vprbrd_i2c_write_hdr));
254
255 ret = usb_bulk_msg(vb->usb_dev,
256 usb_sndbulkpipe(vb->usb_dev,
257 VPRBRD_EP_OUT), wmsg,
258 bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
259 if ((ret < 0) || (bytes_xfer != bytes_actual))
260 return -EREMOTEIO;
261 }
262 return 0;
263}
264
265static int vprbrd_i2c_xfer(struct i2c_adapter *i2c, struct i2c_msg *msgs,
266 int num)
267{
268 struct i2c_msg *pmsg;
269 int i, ret,
270 error = 0;
271 struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
272 struct vprbrd_i2c_addr_msg *amsg =
273 (struct vprbrd_i2c_addr_msg *)vb->buf;
274 struct vprbrd_i2c_status *smsg = (struct vprbrd_i2c_status *)vb->buf;
275
276 dev_dbg(&i2c->dev, "master xfer %d messages:\n", num);
277
278 for (i = 0 ; i < num ; i++) {
279 pmsg = &msgs[i];
280
281 dev_dbg(&i2c->dev,
282 " %d: %s (flags %d) %d bytes to 0x%02x\n",
283 i, pmsg->flags & I2C_M_RD ? "read" : "write",
284 pmsg->flags, pmsg->len, pmsg->addr);
285
286 mutex_lock(&vb->lock);
287
288 if (pmsg->flags & I2C_M_RD) {
289
290 amsg->cmd = VPRBRD_I2C_CMD_ADDR;
291 amsg->unknown2 = 0x00;
292 amsg->unknown3 = 0x00;
293 amsg->addr = pmsg->addr;
294 amsg->unknown1 = 0x01;
295 amsg->len = cpu_to_le16(pmsg->len);
296
297 ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
298 if (ret < 0)
299 error = ret;
300
301 ret = vprbrd_i2c_read(vb, pmsg);
302 if (ret < 0)
303 error = ret;
304
305 ret = vprbrd_i2c_status(i2c, smsg, error);
306 if (ret < 0)
307 error = ret;
308
309 if (error < 0)
310 goto error;
311 } else {
312
313 ret = vprbrd_i2c_write(vb, pmsg);
314
315 amsg->cmd = VPRBRD_I2C_CMD_ADDR;
316 amsg->unknown2 = 0x00;
317 amsg->unknown3 = 0x00;
318 amsg->addr = pmsg->addr;
319 amsg->unknown1 = 0x00;
320 amsg->len = cpu_to_le16(pmsg->len);
321
322 ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
323 if (ret < 0)
324 error = ret;
325
326 ret = vprbrd_i2c_status(i2c, smsg, error);
327 if (ret < 0)
328 error = ret;
329
330 if (error < 0)
331 goto error;
332 }
333 mutex_unlock(&vb->lock);
334 }
335 return num;
336error:
337 mutex_unlock(&vb->lock);
338 return error;
339}
340
341static u32 vprbrd_i2c_func(struct i2c_adapter *i2c)
342{
343 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
344}
345
346
347static const struct i2c_algorithm vprbrd_algorithm = {
348 .master_xfer = vprbrd_i2c_xfer,
349 .functionality = vprbrd_i2c_func,
350};
351
352static const struct i2c_adapter_quirks vprbrd_quirks = {
353 .max_read_len = 2048,
354 .max_write_len = 2048,
355};
356
357static int vprbrd_i2c_probe(struct platform_device *pdev)
358{
359 struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
360 struct vprbrd_i2c *vb_i2c;
361 int ret;
362 int pipe;
363
364 vb_i2c = devm_kzalloc(&pdev->dev, sizeof(*vb_i2c), GFP_KERNEL);
365 if (vb_i2c == NULL)
366 return -ENOMEM;
367
368
369 vb_i2c->i2c.owner = THIS_MODULE;
370 vb_i2c->i2c.class = I2C_CLASS_HWMON;
371 vb_i2c->i2c.algo = &vprbrd_algorithm;
372 vb_i2c->i2c.quirks = &vprbrd_quirks;
373 vb_i2c->i2c.algo_data = vb;
374
375 vb_i2c->bus_freq_param = i2c_bus_param;
376
377 snprintf(vb_i2c->i2c.name, sizeof(vb_i2c->i2c.name),
378 "viperboard at bus %03d device %03d",
379 vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
380
381
382 if ((i2c_bus_param <= VPRBRD_I2C_FREQ_10KHZ)
383 && (i2c_bus_param >= VPRBRD_I2C_FREQ_6MHZ)) {
384 pipe = usb_sndctrlpipe(vb->usb_dev, 0);
385 ret = usb_control_msg(vb->usb_dev, pipe,
386 VPRBRD_USB_REQUEST_I2C_FREQ, VPRBRD_USB_TYPE_OUT,
387 0x0000, 0x0000, &vb_i2c->bus_freq_param, 1,
388 VPRBRD_USB_TIMEOUT_MS);
389 if (ret != 1) {
390 dev_err(&pdev->dev, "failure setting i2c_bus_freq to %d\n",
391 i2c_bus_freq);
392 return -EIO;
393 }
394 } else {
395 dev_err(&pdev->dev,
396 "invalid i2c_bus_freq setting:%d\n", i2c_bus_freq);
397 return -EIO;
398 }
399
400 vb_i2c->i2c.dev.parent = &pdev->dev;
401
402
403 i2c_add_adapter(&vb_i2c->i2c);
404
405 platform_set_drvdata(pdev, vb_i2c);
406
407 return 0;
408}
409
410static int vprbrd_i2c_remove(struct platform_device *pdev)
411{
412 struct vprbrd_i2c *vb_i2c = platform_get_drvdata(pdev);
413
414 i2c_del_adapter(&vb_i2c->i2c);
415
416 return 0;
417}
418
419static struct platform_driver vprbrd_i2c_driver = {
420 .driver.name = "viperboard-i2c",
421 .driver.owner = THIS_MODULE,
422 .probe = vprbrd_i2c_probe,
423 .remove = vprbrd_i2c_remove,
424};
425
426static int __init vprbrd_i2c_init(void)
427{
428 switch (i2c_bus_freq) {
429 case 6000:
430 i2c_bus_param = VPRBRD_I2C_FREQ_6MHZ;
431 break;
432 case 3000:
433 i2c_bus_param = VPRBRD_I2C_FREQ_3MHZ;
434 break;
435 case 1000:
436 i2c_bus_param = VPRBRD_I2C_FREQ_1MHZ;
437 break;
438 case 400:
439 i2c_bus_param = VPRBRD_I2C_FREQ_400KHZ;
440 break;
441 case 200:
442 i2c_bus_param = VPRBRD_I2C_FREQ_200KHZ;
443 break;
444 case 100:
445 i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
446 break;
447 case 10:
448 i2c_bus_param = VPRBRD_I2C_FREQ_10KHZ;
449 break;
450 default:
451 pr_warn("invalid i2c_bus_freq (%d)\n", i2c_bus_freq);
452 i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
453 }
454
455 return platform_driver_register(&vprbrd_i2c_driver);
456}
457subsys_initcall(vprbrd_i2c_init);
458
459static void __exit vprbrd_i2c_exit(void)
460{
461 platform_driver_unregister(&vprbrd_i2c_driver);
462}
463module_exit(vprbrd_i2c_exit);
464
465MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
466MODULE_DESCRIPTION("I2C master driver for Nano River Techs Viperboard");
467MODULE_LICENSE("GPL");
468MODULE_ALIAS("platform:viperboard-i2c");
469
