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14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/interrupt.h>
17#include <linux/i2c.h>
18#include <linux/platform_device.h>
19#include <linux/completion.h>
20#include <linux/io.h>
21#include <linux/delay.h>
22#include <linux/slab.h>
23
24#define SMCR 0x00
25#define SMCR_START (1 << 0)
26#define SMCR_IRIC (1 << 1)
27#define SMCR_BBSY (1 << 2)
28#define SMCR_ACKE (1 << 3)
29#define SMCR_RST (1 << 4)
30#define SMCR_IEIC (1 << 6)
31
32#define SMSMADR 0x02
33
34#define SMMR 0x04
35#define SMMR_MODE0 (1 << 0)
36#define SMMR_MODE1 (1 << 1)
37#define SMMR_CAP (1 << 3)
38#define SMMR_TMMD (1 << 4)
39#define SMMR_SP (1 << 7)
40
41#define SMSADR 0x06
42#define SMTRDR 0x46
43
44struct highlander_i2c_dev {
45 struct device *dev;
46 void __iomem *base;
47 struct i2c_adapter adapter;
48 struct completion cmd_complete;
49 unsigned long last_read_time;
50 int irq;
51 u8 *buf;
52 size_t buf_len;
53};
54
55static bool iic_force_poll, iic_force_normal;
56static int iic_timeout = 1000, iic_read_delay;
57
58static inline void highlander_i2c_irq_enable(struct highlander_i2c_dev *dev)
59{
60 iowrite16(ioread16(dev->base + SMCR) | SMCR_IEIC, dev->base + SMCR);
61}
62
63static inline void highlander_i2c_irq_disable(struct highlander_i2c_dev *dev)
64{
65 iowrite16(ioread16(dev->base + SMCR) & ~SMCR_IEIC, dev->base + SMCR);
66}
67
68static inline void highlander_i2c_start(struct highlander_i2c_dev *dev)
69{
70 iowrite16(ioread16(dev->base + SMCR) | SMCR_START, dev->base + SMCR);
71}
72
73static inline void highlander_i2c_done(struct highlander_i2c_dev *dev)
74{
75 iowrite16(ioread16(dev->base + SMCR) | SMCR_IRIC, dev->base + SMCR);
76}
77
78static void highlander_i2c_setup(struct highlander_i2c_dev *dev)
79{
80 u16 smmr;
81
82 smmr = ioread16(dev->base + SMMR);
83 smmr |= SMMR_TMMD;
84
85 if (iic_force_normal)
86 smmr &= ~SMMR_SP;
87 else
88 smmr |= SMMR_SP;
89
90 iowrite16(smmr, dev->base + SMMR);
91}
92
93static void smbus_write_data(u8 *src, u16 *dst, int len)
94{
95 for (; len > 1; len -= 2) {
96 *dst++ = be16_to_cpup((__be16 *)src);
97 src += 2;
98 }
99
100 if (len)
101 *dst = *src << 8;
102}
103
104static void smbus_read_data(u16 *src, u8 *dst, int len)
105{
106 for (; len > 1; len -= 2) {
107 *(__be16 *)dst = cpu_to_be16p(src++);
108 dst += 2;
109 }
110
111 if (len)
112 *dst = *src >> 8;
113}
114
115static void highlander_i2c_command(struct highlander_i2c_dev *dev,
116 u8 command, int len)
117{
118 unsigned int i;
119 u16 cmd = (command << 8) | command;
120
121 for (i = 0; i < len; i += 2) {
122 if (len - i == 1)
123 cmd = command << 8;
124 iowrite16(cmd, dev->base + SMSADR + i);
125 dev_dbg(dev->dev, "command data[%x] 0x%04x\n", i/2, cmd);
126 }
127}
128
129static int highlander_i2c_wait_for_bbsy(struct highlander_i2c_dev *dev)
130{
131 unsigned long timeout;
132
133 timeout = jiffies + msecs_to_jiffies(iic_timeout);
134 while (ioread16(dev->base + SMCR) & SMCR_BBSY) {
135 if (time_after(jiffies, timeout)) {
136 dev_warn(dev->dev, "timeout waiting for bus ready\n");
137 return -ETIMEDOUT;
138 }
139
140 msleep(1);
141 }
142
143 return 0;
144}
145
146static int highlander_i2c_reset(struct highlander_i2c_dev *dev)
147{
148 iowrite16(ioread16(dev->base + SMCR) | SMCR_RST, dev->base + SMCR);
149 return highlander_i2c_wait_for_bbsy(dev);
150}
151
152static int highlander_i2c_wait_for_ack(struct highlander_i2c_dev *dev)
153{
154 u16 tmp = ioread16(dev->base + SMCR);
155
156 if ((tmp & (SMCR_IRIC | SMCR_ACKE)) == SMCR_ACKE) {
157 dev_warn(dev->dev, "ack abnormality\n");
158 return highlander_i2c_reset(dev);
159 }
160
161 return 0;
162}
163
164static irqreturn_t highlander_i2c_irq(int irq, void *dev_id)
165{
166 struct highlander_i2c_dev *dev = dev_id;
167
168 highlander_i2c_done(dev);
169 complete(&dev->cmd_complete);
170
171 return IRQ_HANDLED;
172}
173
174static void highlander_i2c_poll(struct highlander_i2c_dev *dev)
175{
176 unsigned long timeout;
177 u16 smcr;
178
179 timeout = jiffies + msecs_to_jiffies(iic_timeout);
180 for (;;) {
181 smcr = ioread16(dev->base + SMCR);
182
183
184
185
186
187
188
189 if (smcr & SMCR_IRIC)
190 return;
191 if (time_after(jiffies, timeout))
192 break;
193
194 cpu_relax();
195 cond_resched();
196 }
197
198 dev_err(dev->dev, "polling timed out\n");
199}
200
201static inline int highlander_i2c_wait_xfer_done(struct highlander_i2c_dev *dev)
202{
203 if (dev->irq)
204 wait_for_completion_timeout(&dev->cmd_complete,
205 msecs_to_jiffies(iic_timeout));
206 else
207
208 highlander_i2c_poll(dev);
209
210 return highlander_i2c_wait_for_ack(dev);
211}
212
213static int highlander_i2c_read(struct highlander_i2c_dev *dev)
214{
215 int i, cnt;
216 u16 data[16];
217
218 if (highlander_i2c_wait_for_bbsy(dev))
219 return -EAGAIN;
220
221 highlander_i2c_start(dev);
222
223 if (highlander_i2c_wait_xfer_done(dev)) {
224 dev_err(dev->dev, "Arbitration loss\n");
225 return -EAGAIN;
226 }
227
228
229
230
231
232
233
234
235
236
237
238
239
240 if (iic_read_delay && time_before(jiffies, dev->last_read_time +
241 msecs_to_jiffies(iic_read_delay)))
242 msleep(jiffies_to_msecs((dev->last_read_time +
243 msecs_to_jiffies(iic_read_delay)) - jiffies));
244
245 cnt = (dev->buf_len + 1) >> 1;
246 for (i = 0; i < cnt; i++) {
247 data[i] = ioread16(dev->base + SMTRDR + (i * sizeof(u16)));
248 dev_dbg(dev->dev, "read data[%x] 0x%04x\n", i, data[i]);
249 }
250
251 smbus_read_data(data, dev->buf, dev->buf_len);
252
253 dev->last_read_time = jiffies;
254
255 return 0;
256}
257
258static int highlander_i2c_write(struct highlander_i2c_dev *dev)
259{
260 int i, cnt;
261 u16 data[16];
262
263 smbus_write_data(dev->buf, data, dev->buf_len);
264
265 cnt = (dev->buf_len + 1) >> 1;
266 for (i = 0; i < cnt; i++) {
267 iowrite16(data[i], dev->base + SMTRDR + (i * sizeof(u16)));
268 dev_dbg(dev->dev, "write data[%x] 0x%04x\n", i, data[i]);
269 }
270
271 if (highlander_i2c_wait_for_bbsy(dev))
272 return -EAGAIN;
273
274 highlander_i2c_start(dev);
275
276 return highlander_i2c_wait_xfer_done(dev);
277}
278
279static int highlander_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
280 unsigned short flags, char read_write,
281 u8 command, int size,
282 union i2c_smbus_data *data)
283{
284 struct highlander_i2c_dev *dev = i2c_get_adapdata(adap);
285 u16 tmp;
286
287 init_completion(&dev->cmd_complete);
288
289 dev_dbg(dev->dev, "addr %04x, command %02x, read_write %d, size %d\n",
290 addr, command, read_write, size);
291
292
293
294
295 switch (size) {
296 case I2C_SMBUS_BYTE_DATA:
297 dev->buf = &data->byte;
298 dev->buf_len = 1;
299 break;
300 case I2C_SMBUS_I2C_BLOCK_DATA:
301 dev->buf = &data->block[1];
302 dev->buf_len = data->block[0];
303 break;
304 default:
305 dev_err(dev->dev, "unsupported command %d\n", size);
306 return -EINVAL;
307 }
308
309
310
311
312 tmp = ioread16(dev->base + SMMR);
313 tmp &= ~(SMMR_MODE0 | SMMR_MODE1);
314
315 switch (dev->buf_len) {
316 case 1:
317
318 break;
319 case 8:
320 tmp |= SMMR_MODE0;
321 break;
322 case 16:
323 tmp |= SMMR_MODE1;
324 break;
325 case 32:
326 tmp |= (SMMR_MODE0 | SMMR_MODE1);
327 break;
328 default:
329 dev_err(dev->dev, "unsupported xfer size %d\n", dev->buf_len);
330 return -EINVAL;
331 }
332
333 iowrite16(tmp, dev->base + SMMR);
334
335
336 highlander_i2c_done(dev);
337
338
339 iowrite16((addr << 1) | read_write, dev->base + SMSMADR);
340
341 highlander_i2c_command(dev, command, dev->buf_len);
342
343 if (read_write == I2C_SMBUS_READ)
344 return highlander_i2c_read(dev);
345 else
346 return highlander_i2c_write(dev);
347}
348
349static u32 highlander_i2c_func(struct i2c_adapter *adapter)
350{
351 return I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK;
352}
353
354static const struct i2c_algorithm highlander_i2c_algo = {
355 .smbus_xfer = highlander_i2c_smbus_xfer,
356 .functionality = highlander_i2c_func,
357};
358
359static int __devinit highlander_i2c_probe(struct platform_device *pdev)
360{
361 struct highlander_i2c_dev *dev;
362 struct i2c_adapter *adap;
363 struct resource *res;
364 int ret;
365
366 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
367 if (unlikely(!res)) {
368 dev_err(&pdev->dev, "no mem resource\n");
369 return -ENODEV;
370 }
371
372 dev = kzalloc(sizeof(struct highlander_i2c_dev), GFP_KERNEL);
373 if (unlikely(!dev))
374 return -ENOMEM;
375
376 dev->base = ioremap_nocache(res->start, resource_size(res));
377 if (unlikely(!dev->base)) {
378 ret = -ENXIO;
379 goto err;
380 }
381
382 dev->dev = &pdev->dev;
383 platform_set_drvdata(pdev, dev);
384
385 dev->irq = platform_get_irq(pdev, 0);
386 if (iic_force_poll)
387 dev->irq = 0;
388
389 if (dev->irq) {
390 ret = request_irq(dev->irq, highlander_i2c_irq, 0,
391 pdev->name, dev);
392 if (unlikely(ret))
393 goto err_unmap;
394
395 highlander_i2c_irq_enable(dev);
396 } else {
397 dev_notice(&pdev->dev, "no IRQ, using polling mode\n");
398 highlander_i2c_irq_disable(dev);
399 }
400
401 dev->last_read_time = jiffies;
402
403 highlander_i2c_setup(dev);
404
405 adap = &dev->adapter;
406 i2c_set_adapdata(adap, dev);
407 adap->owner = THIS_MODULE;
408 adap->class = I2C_CLASS_HWMON;
409 strlcpy(adap->name, "HL FPGA I2C adapter", sizeof(adap->name));
410 adap->algo = &highlander_i2c_algo;
411 adap->dev.parent = &pdev->dev;
412 adap->nr = pdev->id;
413
414
415
416
417 ret = highlander_i2c_reset(dev);
418 if (unlikely(ret)) {
419 dev_err(&pdev->dev, "controller didn't come up\n");
420 goto err_free_irq;
421 }
422
423 ret = i2c_add_numbered_adapter(adap);
424 if (unlikely(ret)) {
425 dev_err(&pdev->dev, "failure adding adapter\n");
426 goto err_free_irq;
427 }
428
429 return 0;
430
431err_free_irq:
432 if (dev->irq)
433 free_irq(dev->irq, dev);
434err_unmap:
435 iounmap(dev->base);
436err:
437 kfree(dev);
438
439 platform_set_drvdata(pdev, NULL);
440
441 return ret;
442}
443
444static int __devexit highlander_i2c_remove(struct platform_device *pdev)
445{
446 struct highlander_i2c_dev *dev = platform_get_drvdata(pdev);
447
448 i2c_del_adapter(&dev->adapter);
449
450 if (dev->irq)
451 free_irq(dev->irq, dev);
452
453 iounmap(dev->base);
454 kfree(dev);
455
456 platform_set_drvdata(pdev, NULL);
457
458 return 0;
459}
460
461static struct platform_driver highlander_i2c_driver = {
462 .driver = {
463 .name = "i2c-highlander",
464 .owner = THIS_MODULE,
465 },
466
467 .probe = highlander_i2c_probe,
468 .remove = __devexit_p(highlander_i2c_remove),
469};
470
471module_platform_driver(highlander_i2c_driver);
472
473MODULE_AUTHOR("Paul Mundt");
474MODULE_DESCRIPTION("Renesas Highlander FPGA I2C/SMBus adapter");
475MODULE_LICENSE("GPL v2");
476
477module_param(iic_force_poll, bool, 0);
478module_param(iic_force_normal, bool, 0);
479module_param(iic_timeout, int, 0);
480module_param(iic_read_delay, int, 0);
481
482MODULE_PARM_DESC(iic_force_poll, "Force polling mode");
483MODULE_PARM_DESC(iic_force_normal,
484 "Force normal mode (100 kHz), default is fast mode (400 kHz)");
485MODULE_PARM_DESC(iic_timeout, "Set timeout value in msecs (default 1000 ms)");
486MODULE_PARM_DESC(iic_read_delay,
487 "Delay between data read cycles (default 0 ms)");
488
