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15#include <linux/kernel.h>
16#include <linux/errno.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/types.h>
20#include <linux/mutex.h>
21#include <linux/platform_device.h>
22
23#include <linux/usb.h>
24#include <linux/i2c.h>
25
26#include <linux/mfd/viperboard.h>
27
28struct vprbrd_i2c {
29 struct i2c_adapter i2c;
30 u8 bus_freq_param;
31};
32
33
34static u8 i2c_bus_param;
35static unsigned int i2c_bus_freq = 100;
36module_param(i2c_bus_freq, int, 0);
37MODULE_PARM_DESC(i2c_bus_freq,
38 "i2c bus frequency in khz (default is 100) valid values: 10, 100, 200, 400, 1000, 3000, 6000");
39
40static int vprbrd_i2c_status(struct i2c_adapter *i2c,
41 struct vprbrd_i2c_status *status, bool prev_error)
42{
43 u16 bytes_xfer;
44 int ret;
45 struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
46
47
48 bytes_xfer = sizeof(struct vprbrd_i2c_status);
49
50 ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
51 VPRBRD_USB_REQUEST_I2C, VPRBRD_USB_TYPE_IN, 0x0000, 0x0000,
52 status, bytes_xfer, VPRBRD_USB_TIMEOUT_MS);
53
54 if (ret != bytes_xfer)
55 prev_error = true;
56
57 if (prev_error) {
58 dev_err(&i2c->dev, "failure in usb communication\n");
59 return -EREMOTEIO;
60 }
61
62 dev_dbg(&i2c->dev, " status = %d\n", status->status);
63 if (status->status != 0x00) {
64 dev_err(&i2c->dev, "failure: i2c protocol error\n");
65 return -EPROTO;
66 }
67 return 0;
68}
69
70static int vprbrd_i2c_receive(struct usb_device *usb_dev,
71 struct vprbrd_i2c_read_msg *rmsg, int bytes_xfer)
72{
73 int ret, bytes_actual;
74 int error = 0;
75
76
77 ret = usb_bulk_msg(usb_dev,
78 usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), rmsg,
79 sizeof(struct vprbrd_i2c_read_hdr), &bytes_actual,
80 VPRBRD_USB_TIMEOUT_MS);
81
82 if ((ret < 0)
83 || (bytes_actual != sizeof(struct vprbrd_i2c_read_hdr))) {
84 dev_err(&usb_dev->dev, "failure transmitting usb\n");
85 error = -EREMOTEIO;
86 }
87
88
89 ret = usb_bulk_msg(usb_dev,
90 usb_rcvbulkpipe(usb_dev, VPRBRD_EP_IN), rmsg,
91 bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
92
93 if ((ret < 0) || (bytes_xfer != bytes_actual)) {
94 dev_err(&usb_dev->dev, "failure receiving usb\n");
95 error = -EREMOTEIO;
96 }
97 return error;
98}
99
100static int vprbrd_i2c_addr(struct usb_device *usb_dev,
101 struct vprbrd_i2c_addr_msg *amsg)
102{
103 int ret, bytes_actual;
104
105 ret = usb_bulk_msg(usb_dev,
106 usb_sndbulkpipe(usb_dev, VPRBRD_EP_OUT), amsg,
107 sizeof(struct vprbrd_i2c_addr_msg), &bytes_actual,
108 VPRBRD_USB_TIMEOUT_MS);
109
110 if ((ret < 0) ||
111 (sizeof(struct vprbrd_i2c_addr_msg) != bytes_actual)) {
112 dev_err(&usb_dev->dev, "failure transmitting usb\n");
113 return -EREMOTEIO;
114 }
115 return 0;
116}
117
118static int vprbrd_i2c_read(struct vprbrd *vb, struct i2c_msg *msg)
119{
120 int ret;
121 u16 remain_len, len1, len2, start = 0x0000;
122 struct vprbrd_i2c_read_msg *rmsg =
123 (struct vprbrd_i2c_read_msg *)vb->buf;
124
125 remain_len = msg->len;
126 rmsg->header.cmd = VPRBRD_I2C_CMD_READ;
127 while (remain_len > 0) {
128 rmsg->header.addr = cpu_to_le16(start + 0x4000);
129 if (remain_len <= 255) {
130 len1 = remain_len;
131 len2 = 0x00;
132 rmsg->header.len0 = remain_len;
133 rmsg->header.len1 = 0x00;
134 rmsg->header.len2 = 0x00;
135 rmsg->header.len3 = 0x00;
136 rmsg->header.len4 = 0x00;
137 rmsg->header.len5 = 0x00;
138 remain_len = 0;
139 } else if (remain_len <= 510) {
140 len1 = remain_len;
141 len2 = 0x00;
142 rmsg->header.len0 = remain_len - 255;
143 rmsg->header.len1 = 0xff;
144 rmsg->header.len2 = 0x00;
145 rmsg->header.len3 = 0x00;
146 rmsg->header.len4 = 0x00;
147 rmsg->header.len5 = 0x00;
148 remain_len = 0;
149 } else if (remain_len <= 512) {
150 len1 = remain_len;
151 len2 = 0x00;
152 rmsg->header.len0 = remain_len - 510;
153 rmsg->header.len1 = 0xff;
154 rmsg->header.len2 = 0xff;
155 rmsg->header.len3 = 0x00;
156 rmsg->header.len4 = 0x00;
157 rmsg->header.len5 = 0x00;
158 remain_len = 0;
159 } else if (remain_len <= 767) {
160 len1 = 512;
161 len2 = remain_len - 512;
162 rmsg->header.len0 = 0x02;
163 rmsg->header.len1 = 0xff;
164 rmsg->header.len2 = 0xff;
165 rmsg->header.len3 = remain_len - 512;
166 rmsg->header.len4 = 0x00;
167 rmsg->header.len5 = 0x00;
168 remain_len = 0;
169 } else if (remain_len <= 1022) {
170 len1 = 512;
171 len2 = remain_len - 512;
172 rmsg->header.len0 = 0x02;
173 rmsg->header.len1 = 0xff;
174 rmsg->header.len2 = 0xff;
175 rmsg->header.len3 = remain_len - 767;
176 rmsg->header.len4 = 0xff;
177 rmsg->header.len5 = 0x00;
178 remain_len = 0;
179 } else if (remain_len <= 1024) {
180 len1 = 512;
181 len2 = remain_len - 512;
182 rmsg->header.len0 = 0x02;
183 rmsg->header.len1 = 0xff;
184 rmsg->header.len2 = 0xff;
185 rmsg->header.len3 = remain_len - 1022;
186 rmsg->header.len4 = 0xff;
187 rmsg->header.len5 = 0xff;
188 remain_len = 0;
189 } else {
190 len1 = 512;
191 len2 = 512;
192 rmsg->header.len0 = 0x02;
193 rmsg->header.len1 = 0xff;
194 rmsg->header.len2 = 0xff;
195 rmsg->header.len3 = 0x02;
196 rmsg->header.len4 = 0xff;
197 rmsg->header.len5 = 0xff;
198 remain_len -= 1024;
199 start += 1024;
200 }
201 rmsg->header.tf1 = cpu_to_le16(len1);
202 rmsg->header.tf2 = cpu_to_le16(len2);
203
204
205 ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len1);
206 if (ret < 0)
207 return ret;
208
209 memcpy(msg->buf + start, rmsg, len1);
210
211
212 if (len2 > 0) {
213 ret = vprbrd_i2c_receive(vb->usb_dev, rmsg, len2);
214 if (ret < 0)
215 return ret;
216
217 memcpy(msg->buf + start + 512, rmsg, len2);
218 }
219 }
220 return 0;
221}
222
223static int vprbrd_i2c_write(struct vprbrd *vb, struct i2c_msg *msg)
224{
225 int ret, bytes_actual;
226 u16 remain_len, bytes_xfer,
227 start = 0x0000;
228 struct vprbrd_i2c_write_msg *wmsg =
229 (struct vprbrd_i2c_write_msg *)vb->buf;
230
231 remain_len = msg->len;
232 wmsg->header.cmd = VPRBRD_I2C_CMD_WRITE;
233 wmsg->header.last = 0x00;
234 wmsg->header.chan = 0x00;
235 wmsg->header.spi = 0x0000;
236 while (remain_len > 0) {
237 wmsg->header.addr = cpu_to_le16(start + 0x4000);
238 if (remain_len > 503) {
239 wmsg->header.len1 = 0xff;
240 wmsg->header.len2 = 0xf8;
241 remain_len -= 503;
242 bytes_xfer = 503 + sizeof(struct vprbrd_i2c_write_hdr);
243 start += 503;
244 } else if (remain_len > 255) {
245 wmsg->header.len1 = 0xff;
246 wmsg->header.len2 = (remain_len - 255);
247 bytes_xfer = remain_len +
248 sizeof(struct vprbrd_i2c_write_hdr);
249 remain_len = 0;
250 } else {
251 wmsg->header.len1 = remain_len;
252 wmsg->header.len2 = 0x00;
253 bytes_xfer = remain_len +
254 sizeof(struct vprbrd_i2c_write_hdr);
255 remain_len = 0;
256 }
257 memcpy(wmsg->data, msg->buf + start,
258 bytes_xfer - sizeof(struct vprbrd_i2c_write_hdr));
259
260 ret = usb_bulk_msg(vb->usb_dev,
261 usb_sndbulkpipe(vb->usb_dev,
262 VPRBRD_EP_OUT), wmsg,
263 bytes_xfer, &bytes_actual, VPRBRD_USB_TIMEOUT_MS);
264 if ((ret < 0) || (bytes_xfer != bytes_actual))
265 return -EREMOTEIO;
266 }
267 return 0;
268}
269
270static int vprbrd_i2c_xfer(struct i2c_adapter *i2c, struct i2c_msg *msgs,
271 int num)
272{
273 struct i2c_msg *pmsg;
274 int i, ret,
275 error = 0;
276 struct vprbrd *vb = (struct vprbrd *)i2c->algo_data;
277 struct vprbrd_i2c_addr_msg *amsg =
278 (struct vprbrd_i2c_addr_msg *)vb->buf;
279 struct vprbrd_i2c_status *smsg = (struct vprbrd_i2c_status *)vb->buf;
280
281 dev_dbg(&i2c->dev, "master xfer %d messages:\n", num);
282
283 for (i = 0 ; i < num ; i++) {
284 pmsg = &msgs[i];
285
286 dev_dbg(&i2c->dev,
287 " %d: %s (flags %d) %d bytes to 0x%02x\n",
288 i, pmsg->flags & I2C_M_RD ? "read" : "write",
289 pmsg->flags, pmsg->len, pmsg->addr);
290
291 mutex_lock(&vb->lock);
292
293 if (pmsg->flags & I2C_M_RD) {
294
295 amsg->cmd = VPRBRD_I2C_CMD_ADDR;
296 amsg->unknown2 = 0x00;
297 amsg->unknown3 = 0x00;
298 amsg->addr = pmsg->addr;
299 amsg->unknown1 = 0x01;
300 amsg->len = cpu_to_le16(pmsg->len);
301
302 ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
303 if (ret < 0)
304 error = ret;
305
306 ret = vprbrd_i2c_read(vb, pmsg);
307 if (ret < 0)
308 error = ret;
309
310 ret = vprbrd_i2c_status(i2c, smsg, error);
311 if (ret < 0)
312 error = ret;
313
314 if (error < 0)
315 goto error;
316 } else {
317
318 ret = vprbrd_i2c_write(vb, pmsg);
319
320 amsg->cmd = VPRBRD_I2C_CMD_ADDR;
321 amsg->unknown2 = 0x00;
322 amsg->unknown3 = 0x00;
323 amsg->addr = pmsg->addr;
324 amsg->unknown1 = 0x00;
325 amsg->len = cpu_to_le16(pmsg->len);
326
327 ret = vprbrd_i2c_addr(vb->usb_dev, amsg);
328 if (ret < 0)
329 error = ret;
330
331 ret = vprbrd_i2c_status(i2c, smsg, error);
332 if (ret < 0)
333 error = ret;
334
335 if (error < 0)
336 goto error;
337 }
338 mutex_unlock(&vb->lock);
339 }
340 return 0;
341error:
342 mutex_unlock(&vb->lock);
343 return error;
344}
345
346static u32 vprbrd_i2c_func(struct i2c_adapter *i2c)
347{
348 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
349}
350
351
352static const struct i2c_algorithm vprbrd_algorithm = {
353 .master_xfer = vprbrd_i2c_xfer,
354 .functionality = vprbrd_i2c_func,
355};
356
357static struct i2c_adapter_quirks vprbrd_quirks = {
358 .max_read_len = 2048,
359 .max_write_len = 2048,
360};
361
362static int vprbrd_i2c_probe(struct platform_device *pdev)
363{
364 struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
365 struct vprbrd_i2c *vb_i2c;
366 int ret;
367 int pipe;
368
369 vb_i2c = devm_kzalloc(&pdev->dev, sizeof(*vb_i2c), GFP_KERNEL);
370 if (vb_i2c == NULL)
371 return -ENOMEM;
372
373
374 vb_i2c->i2c.owner = THIS_MODULE;
375 vb_i2c->i2c.class = I2C_CLASS_HWMON;
376 vb_i2c->i2c.algo = &vprbrd_algorithm;
377 vb_i2c->i2c.quirks = &vprbrd_quirks;
378 vb_i2c->i2c.algo_data = vb;
379
380 vb_i2c->bus_freq_param = i2c_bus_param;
381
382 snprintf(vb_i2c->i2c.name, sizeof(vb_i2c->i2c.name),
383 "viperboard at bus %03d device %03d",
384 vb->usb_dev->bus->busnum, vb->usb_dev->devnum);
385
386
387 if ((i2c_bus_param <= VPRBRD_I2C_FREQ_10KHZ)
388 && (i2c_bus_param >= VPRBRD_I2C_FREQ_6MHZ)) {
389 pipe = usb_sndctrlpipe(vb->usb_dev, 0);
390 ret = usb_control_msg(vb->usb_dev, pipe,
391 VPRBRD_USB_REQUEST_I2C_FREQ, VPRBRD_USB_TYPE_OUT,
392 0x0000, 0x0000, &vb_i2c->bus_freq_param, 1,
393 VPRBRD_USB_TIMEOUT_MS);
394 if (ret != 1) {
395 dev_err(&pdev->dev, "failure setting i2c_bus_freq to %d\n",
396 i2c_bus_freq);
397 return -EIO;
398 }
399 } else {
400 dev_err(&pdev->dev,
401 "invalid i2c_bus_freq setting:%d\n", i2c_bus_freq);
402 return -EIO;
403 }
404
405 vb_i2c->i2c.dev.parent = &pdev->dev;
406
407
408 i2c_add_adapter(&vb_i2c->i2c);
409
410 platform_set_drvdata(pdev, vb_i2c);
411
412 return 0;
413}
414
415static int vprbrd_i2c_remove(struct platform_device *pdev)
416{
417 struct vprbrd_i2c *vb_i2c = platform_get_drvdata(pdev);
418
419 i2c_del_adapter(&vb_i2c->i2c);
420
421 return 0;
422}
423
424static struct platform_driver vprbrd_i2c_driver = {
425 .driver.name = "viperboard-i2c",
426 .driver.owner = THIS_MODULE,
427 .probe = vprbrd_i2c_probe,
428 .remove = vprbrd_i2c_remove,
429};
430
431static int __init vprbrd_i2c_init(void)
432{
433 switch (i2c_bus_freq) {
434 case 6000:
435 i2c_bus_param = VPRBRD_I2C_FREQ_6MHZ;
436 break;
437 case 3000:
438 i2c_bus_param = VPRBRD_I2C_FREQ_3MHZ;
439 break;
440 case 1000:
441 i2c_bus_param = VPRBRD_I2C_FREQ_1MHZ;
442 break;
443 case 400:
444 i2c_bus_param = VPRBRD_I2C_FREQ_400KHZ;
445 break;
446 case 200:
447 i2c_bus_param = VPRBRD_I2C_FREQ_200KHZ;
448 break;
449 case 100:
450 i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
451 break;
452 case 10:
453 i2c_bus_param = VPRBRD_I2C_FREQ_10KHZ;
454 break;
455 default:
456 pr_warn("invalid i2c_bus_freq (%d)\n", i2c_bus_freq);
457 i2c_bus_param = VPRBRD_I2C_FREQ_100KHZ;
458 }
459
460 return platform_driver_register(&vprbrd_i2c_driver);
461}
462subsys_initcall(vprbrd_i2c_init);
463
464static void __exit vprbrd_i2c_exit(void)
465{
466 platform_driver_unregister(&vprbrd_i2c_driver);
467}
468module_exit(vprbrd_i2c_exit);
469
470MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
471MODULE_DESCRIPTION("I2C master driver for Nano River Techs Viperboard");
472MODULE_LICENSE("GPL");
473MODULE_ALIAS("platform:viperboard-i2c");
474
