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