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32#include <linux/interrupt.h>
33#include <linux/kernel.h>
34#include <linux/module.h>
35#include <linux/delay.h>
36#include <linux/slab.h>
37#include <linux/init.h>
38#include <linux/errno.h>
39#include <linux/platform_device.h>
40#include <linux/i2c.h>
41#include <linux/io.h>
42#include <linux/gpio.h>
43
44#include "i2c-iop3xx.h"
45
46
47static int i2c_id;
48
49static inline unsigned char
50iic_cook_addr(struct i2c_msg *msg)
51{
52 unsigned char addr;
53
54 addr = (msg->addr << 1);
55
56 if (msg->flags & I2C_M_RD)
57 addr |= 1;
58
59 return addr;
60}
61
62static void
63iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap)
64{
65
66 __raw_writel(IOP3XX_ICR_UNIT_RESET, iop3xx_adap->ioaddr + CR_OFFSET);
67 __raw_writel(IOP3XX_ISR_CLEARBITS, iop3xx_adap->ioaddr + SR_OFFSET);
68 __raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET);
69}
70
71static void
72iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap)
73{
74 u32 cr = IOP3XX_ICR_GCD | IOP3XX_ICR_SCLEN | IOP3XX_ICR_UE;
75
76
77
78
79
80#if defined(CONFIG_ARCH_IOP32X) || defined(CONFIG_ARCH_IOP33X)
81 if (iop3xx_adap->id == 0) {
82 gpio_set_value(7, 0);
83 gpio_set_value(6, 0);
84 } else {
85 gpio_set_value(5, 0);
86 gpio_set_value(4, 0);
87 }
88#endif
89
90 iop3xx_adap->SR_enabled =
91 IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD |
92 IOP3XX_ISR_RXFULL | IOP3XX_ISR_TXEMPTY;
93
94 cr |= IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
95 IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE;
96
97 __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
98}
99
100static void
101iop3xx_i2c_transaction_cleanup(struct i2c_algo_iop3xx_data *iop3xx_adap)
102{
103 unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
104
105 cr &= ~(IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE |
106 IOP3XX_ICR_MSTOP | IOP3XX_ICR_SCLEN);
107
108 __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
109}
110
111
112
113
114
115static irqreturn_t
116iop3xx_i2c_irq_handler(int this_irq, void *dev_id)
117{
118 struct i2c_algo_iop3xx_data *iop3xx_adap = dev_id;
119 u32 sr = __raw_readl(iop3xx_adap->ioaddr + SR_OFFSET);
120
121 if ((sr &= iop3xx_adap->SR_enabled)) {
122 __raw_writel(sr, iop3xx_adap->ioaddr + SR_OFFSET);
123 iop3xx_adap->SR_received |= sr;
124 wake_up_interruptible(&iop3xx_adap->waitq);
125 }
126 return IRQ_HANDLED;
127}
128
129
130static int
131iop3xx_i2c_error(u32 sr)
132{
133 int rc = 0;
134
135 if ((sr & IOP3XX_ISR_BERRD)) {
136 if ( !rc ) rc = -I2C_ERR_BERR;
137 }
138 if ((sr & IOP3XX_ISR_ALD)) {
139 if ( !rc ) rc = -I2C_ERR_ALD;
140 }
141 return rc;
142}
143
144static inline u32
145iop3xx_i2c_get_srstat(struct i2c_algo_iop3xx_data *iop3xx_adap)
146{
147 unsigned long flags;
148 u32 sr;
149
150 spin_lock_irqsave(&iop3xx_adap->lock, flags);
151 sr = iop3xx_adap->SR_received;
152 iop3xx_adap->SR_received = 0;
153 spin_unlock_irqrestore(&iop3xx_adap->lock, flags);
154
155 return sr;
156}
157
158
159
160
161
162typedef int (* compare_func)(unsigned test, unsigned mask);
163
164
165static int
166iop3xx_i2c_wait_event(struct i2c_algo_iop3xx_data *iop3xx_adap,
167 unsigned flags, unsigned* status,
168 compare_func compare)
169{
170 unsigned sr = 0;
171 int interrupted;
172 int done;
173 int rc = 0;
174
175 do {
176 interrupted = wait_event_interruptible_timeout (
177 iop3xx_adap->waitq,
178 (done = compare( sr = iop3xx_i2c_get_srstat(iop3xx_adap) ,flags )),
179 1 * HZ
180 );
181 if ((rc = iop3xx_i2c_error(sr)) < 0) {
182 *status = sr;
183 return rc;
184 } else if (!interrupted) {
185 *status = sr;
186 return -ETIMEDOUT;
187 }
188 } while(!done);
189
190 *status = sr;
191
192 return 0;
193}
194
195
196
197
198static int
199all_bits_clear(unsigned test, unsigned mask)
200{
201 return (test & mask) == 0;
202}
203
204static int
205any_bits_set(unsigned test, unsigned mask)
206{
207 return (test & mask) != 0;
208}
209
210static int
211iop3xx_i2c_wait_tx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
212{
213 return iop3xx_i2c_wait_event(
214 iop3xx_adap,
215 IOP3XX_ISR_TXEMPTY | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
216 status, any_bits_set);
217}
218
219static int
220iop3xx_i2c_wait_rx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
221{
222 return iop3xx_i2c_wait_event(
223 iop3xx_adap,
224 IOP3XX_ISR_RXFULL | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
225 status, any_bits_set);
226}
227
228static int
229iop3xx_i2c_wait_idle(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
230{
231 return iop3xx_i2c_wait_event(
232 iop3xx_adap, IOP3XX_ISR_UNITBUSY, status, all_bits_clear);
233}
234
235static int
236iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap,
237 struct i2c_msg* msg)
238{
239 unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
240 int status;
241 int rc;
242
243
244
245
246 if (msg->addr == MYSAR) {
247 return -EBUSY;
248 }
249
250 __raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET);
251
252 cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
253 cr |= IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE;
254
255 __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
256 rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
257
258 return rc;
259}
260
261static int
262iop3xx_i2c_write_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char byte,
263 int stop)
264{
265 unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
266 int status;
267 int rc = 0;
268
269 __raw_writel(byte, iop3xx_adap->ioaddr + DBR_OFFSET);
270 cr &= ~IOP3XX_ICR_MSTART;
271 if (stop) {
272 cr |= IOP3XX_ICR_MSTOP;
273 } else {
274 cr &= ~IOP3XX_ICR_MSTOP;
275 }
276 cr |= IOP3XX_ICR_TBYTE;
277 __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
278 rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
279
280 return rc;
281}
282
283static int
284iop3xx_i2c_read_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char* byte,
285 int stop)
286{
287 unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
288 int status;
289 int rc = 0;
290
291 cr &= ~IOP3XX_ICR_MSTART;
292
293 if (stop) {
294 cr |= IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK;
295 } else {
296 cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
297 }
298 cr |= IOP3XX_ICR_TBYTE;
299 __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
300
301 rc = iop3xx_i2c_wait_rx_done(iop3xx_adap, &status);
302
303 *byte = __raw_readl(iop3xx_adap->ioaddr + DBR_OFFSET);
304
305 return rc;
306}
307
308static int
309iop3xx_i2c_writebytes(struct i2c_adapter *i2c_adap, const char *buf, int count)
310{
311 struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
312 int ii;
313 int rc = 0;
314
315 for (ii = 0; rc == 0 && ii != count; ++ii)
316 rc = iop3xx_i2c_write_byte(iop3xx_adap, buf[ii], ii==count-1);
317 return rc;
318}
319
320static int
321iop3xx_i2c_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count)
322{
323 struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
324 int ii;
325 int rc = 0;
326
327 for (ii = 0; rc == 0 && ii != count; ++ii)
328 rc = iop3xx_i2c_read_byte(iop3xx_adap, &buf[ii], ii==count-1);
329
330 return rc;
331}
332
333
334
335
336
337
338
339
340static int
341iop3xx_i2c_handle_msg(struct i2c_adapter *i2c_adap, struct i2c_msg* pmsg)
342{
343 struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
344 int rc;
345
346 rc = iop3xx_i2c_send_target_addr(iop3xx_adap, pmsg);
347 if (rc < 0) {
348 return rc;
349 }
350
351 if ((pmsg->flags&I2C_M_RD)) {
352 return iop3xx_i2c_readbytes(i2c_adap, pmsg->buf, pmsg->len);
353 } else {
354 return iop3xx_i2c_writebytes(i2c_adap, pmsg->buf, pmsg->len);
355 }
356}
357
358
359
360
361static int
362iop3xx_i2c_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
363 int num)
364{
365 struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
366 int im = 0;
367 int ret = 0;
368 int status;
369
370 iop3xx_i2c_wait_idle(iop3xx_adap, &status);
371 iop3xx_i2c_reset(iop3xx_adap);
372 iop3xx_i2c_enable(iop3xx_adap);
373
374 for (im = 0; ret == 0 && im != num; im++) {
375 ret = iop3xx_i2c_handle_msg(i2c_adap, &msgs[im]);
376 }
377
378 iop3xx_i2c_transaction_cleanup(iop3xx_adap);
379
380 if(ret)
381 return ret;
382
383 return im;
384}
385
386static u32
387iop3xx_i2c_func(struct i2c_adapter *adap)
388{
389 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
390}
391
392static const struct i2c_algorithm iop3xx_i2c_algo = {
393 .master_xfer = iop3xx_i2c_master_xfer,
394 .functionality = iop3xx_i2c_func,
395};
396
397static int
398iop3xx_i2c_remove(struct platform_device *pdev)
399{
400 struct i2c_adapter *padapter = platform_get_drvdata(pdev);
401 struct i2c_algo_iop3xx_data *adapter_data =
402 (struct i2c_algo_iop3xx_data *)padapter->algo_data;
403 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
404 unsigned long cr = __raw_readl(adapter_data->ioaddr + CR_OFFSET);
405
406
407
408
409 cr &= ~(IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
410 IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE);
411 __raw_writel(cr, adapter_data->ioaddr + CR_OFFSET);
412
413 iounmap(adapter_data->ioaddr);
414 release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
415 kfree(adapter_data);
416 kfree(padapter);
417
418 return 0;
419}
420
421static int
422iop3xx_i2c_probe(struct platform_device *pdev)
423{
424 struct resource *res;
425 int ret, irq;
426 struct i2c_adapter *new_adapter;
427 struct i2c_algo_iop3xx_data *adapter_data;
428
429 new_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
430 if (!new_adapter) {
431 ret = -ENOMEM;
432 goto out;
433 }
434
435 adapter_data = kzalloc(sizeof(struct i2c_algo_iop3xx_data), GFP_KERNEL);
436 if (!adapter_data) {
437 ret = -ENOMEM;
438 goto free_adapter;
439 }
440
441 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
442 if (!res) {
443 ret = -ENODEV;
444 goto free_both;
445 }
446
447 if (!request_mem_region(res->start, IOP3XX_I2C_IO_SIZE, pdev->name)) {
448 ret = -EBUSY;
449 goto free_both;
450 }
451
452
453 adapter_data->id = i2c_id++;
454
455 adapter_data->ioaddr = ioremap(res->start, IOP3XX_I2C_IO_SIZE);
456 if (!adapter_data->ioaddr) {
457 ret = -ENOMEM;
458 goto release_region;
459 }
460
461 irq = platform_get_irq(pdev, 0);
462 if (irq < 0) {
463 ret = -ENXIO;
464 goto unmap;
465 }
466 ret = request_irq(irq, iop3xx_i2c_irq_handler, 0,
467 pdev->name, adapter_data);
468
469 if (ret) {
470 ret = -EIO;
471 goto unmap;
472 }
473
474 memcpy(new_adapter->name, pdev->name, strlen(pdev->name));
475 new_adapter->owner = THIS_MODULE;
476 new_adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
477 new_adapter->dev.parent = &pdev->dev;
478 new_adapter->nr = pdev->id;
479
480
481
482
483 new_adapter->timeout = HZ;
484 new_adapter->algo = &iop3xx_i2c_algo;
485
486 init_waitqueue_head(&adapter_data->waitq);
487 spin_lock_init(&adapter_data->lock);
488
489 iop3xx_i2c_reset(adapter_data);
490 iop3xx_i2c_enable(adapter_data);
491
492 platform_set_drvdata(pdev, new_adapter);
493 new_adapter->algo_data = adapter_data;
494
495 i2c_add_numbered_adapter(new_adapter);
496
497 return 0;
498
499unmap:
500 iounmap(adapter_data->ioaddr);
501
502release_region:
503 release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
504
505free_both:
506 kfree(adapter_data);
507
508free_adapter:
509 kfree(new_adapter);
510
511out:
512 return ret;
513}
514
515
516static struct platform_driver iop3xx_i2c_driver = {
517 .probe = iop3xx_i2c_probe,
518 .remove = iop3xx_i2c_remove,
519 .driver = {
520 .owner = THIS_MODULE,
521 .name = "IOP3xx-I2C",
522 },
523};
524
525module_platform_driver(iop3xx_i2c_driver);
526
527MODULE_AUTHOR("D-TACQ Solutions Ltd <www.d-tacq.com>");
528MODULE_DESCRIPTION("IOP3xx iic algorithm and driver");
529MODULE_LICENSE("GPL");
530MODULE_ALIAS("platform:IOP3xx-I2C");
531
