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e1000e: cleanup PARENTHESIS_ALIGNMENT checkpatch checks
[linux/fpc-iii.git] / drivers / i2c / busses / i2c-mv64xxx.c
blob8b20ef8524acb0f380defb7968d5c38751b5fd56
1 /*
2 * Driver for the i2c controller on the Marvell line of host bridges
3 * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family).
4 *
5 * Author: Mark A. Greer <mgreer@mvista.com>
6 *
7 * 2005 (c) MontaVista, Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
10 * or implied.
11 */
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/module.h>
15 #include <linux/spinlock.h>
16 #include <linux/i2c.h>
17 #include <linux/interrupt.h>
18 #include <linux/mv643xx_i2c.h>
19 #include <linux/platform_device.h>
20 #include <linux/io.h>
21 #include <linux/of.h>
22 #include <linux/of_irq.h>
23 #include <linux/of_i2c.h>
24 #include <linux/clk.h>
25 #include <linux/err.h>
26
27 /* Register defines */
28 #define MV64XXX_I2C_REG_SLAVE_ADDR 0x00
29 #define MV64XXX_I2C_REG_DATA 0x04
30 #define MV64XXX_I2C_REG_CONTROL 0x08
31 #define MV64XXX_I2C_REG_STATUS 0x0c
32 #define MV64XXX_I2C_REG_BAUD 0x0c
33 #define MV64XXX_I2C_REG_EXT_SLAVE_ADDR 0x10
34 #define MV64XXX_I2C_REG_SOFT_RESET 0x1c
35
36 #define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004
37 #define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008
38 #define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010
39 #define MV64XXX_I2C_REG_CONTROL_START 0x00000020
40 #define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040
41 #define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080
42
43 /* Ctlr status values */
44 #define MV64XXX_I2C_STATUS_BUS_ERR 0x00
45 #define MV64XXX_I2C_STATUS_MAST_START 0x08
46 #define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
47 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
48 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
49 #define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
50 #define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
51 #define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
52 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
53 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
54 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
55 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
56 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
57 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
58 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
59 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
60 #define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
61
62 /* Driver states */
63 enum {
64 MV64XXX_I2C_STATE_INVALID,
65 MV64XXX_I2C_STATE_IDLE,
66 MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
67 MV64XXX_I2C_STATE_WAITING_FOR_RESTART,
68 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
69 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
70 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
71 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
72 };
73
74 /* Driver actions */
75 enum {
76 MV64XXX_I2C_ACTION_INVALID,
77 MV64XXX_I2C_ACTION_CONTINUE,
78 MV64XXX_I2C_ACTION_SEND_START,
79 MV64XXX_I2C_ACTION_SEND_RESTART,
80 MV64XXX_I2C_ACTION_SEND_ADDR_1,
81 MV64XXX_I2C_ACTION_SEND_ADDR_2,
82 MV64XXX_I2C_ACTION_SEND_DATA,
83 MV64XXX_I2C_ACTION_RCV_DATA,
84 MV64XXX_I2C_ACTION_RCV_DATA_STOP,
85 MV64XXX_I2C_ACTION_SEND_STOP,
86 };
87
88 struct mv64xxx_i2c_data {
89 int irq;
90 u32 state;
91 u32 action;
92 u32 aborting;
93 u32 cntl_bits;
94 void __iomem *reg_base;
95 u32 reg_base_p;
96 u32 reg_size;
97 u32 addr1;
98 u32 addr2;
99 u32 bytes_left;
100 u32 byte_posn;
101 u32 send_stop;
102 u32 block;
103 int rc;
104 u32 freq_m;
105 u32 freq_n;
106 #if defined(CONFIG_HAVE_CLK)
107 struct clk *clk;
108 #endif
109 wait_queue_head_t waitq;
110 spinlock_t lock;
111 struct i2c_msg *msg;
112 struct i2c_adapter adapter;
113 };
114
115 /*
116 *****************************************************************************
117 *
118 * Finite State Machine & Interrupt Routines
119 *
120 *****************************************************************************
121 */
122
123 /* Reset hardware and initialize FSM */
124 static void
125 mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
126 {
127 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET);
128 writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
129 drv_data->reg_base + MV64XXX_I2C_REG_BAUD);
130 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR);
131 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
132 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
133 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
134 drv_data->state = MV64XXX_I2C_STATE_IDLE;
135 }
136
137 static void
138 mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
139 {
140 /*
141 * If state is idle, then this is likely the remnants of an old
142 * operation that driver has given up on or the user has killed.
143 * If so, issue the stop condition and go to idle.
144 */
145 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
146 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
147 return;
148 }
149
150 /* The status from the ctlr [mostly] tells us what to do next */
151 switch (status) {
152 /* Start condition interrupt */
153 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
154 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
155 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
156 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
157 break;
158
159 /* Performing a write */
160 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
161 if (drv_data->msg->flags & I2C_M_TEN) {
162 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
163 drv_data->state =
164 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
165 break;
166 }
167 /* FALLTHRU */
168 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
169 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
170 if ((drv_data->bytes_left == 0)
171 || (drv_data->aborting
172 && (drv_data->byte_posn != 0))) {
173 if (drv_data->send_stop) {
174 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
175 drv_data->state = MV64XXX_I2C_STATE_IDLE;
176 } else {
177 drv_data->action =
178 MV64XXX_I2C_ACTION_SEND_RESTART;
179 drv_data->state =
180 MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
181 }
182 } else {
183 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
184 drv_data->state =
185 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
186 drv_data->bytes_left--;
187 }
188 break;
189
190 /* Performing a read */
191 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
192 if (drv_data->msg->flags & I2C_M_TEN) {
193 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
194 drv_data->state =
195 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
196 break;
197 }
198 /* FALLTHRU */
199 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
200 if (drv_data->bytes_left == 0) {
201 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
202 drv_data->state = MV64XXX_I2C_STATE_IDLE;
203 break;
204 }
205 /* FALLTHRU */
206 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
207 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
208 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
209 else {
210 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
211 drv_data->bytes_left--;
212 }
213 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
214
215 if ((drv_data->bytes_left == 1) || drv_data->aborting)
216 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
217 break;
218
219 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
220 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
221 drv_data->state = MV64XXX_I2C_STATE_IDLE;
222 break;
223
224 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
225 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
226 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
227 /* Doesn't seem to be a device at other end */
228 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
229 drv_data->state = MV64XXX_I2C_STATE_IDLE;
230 drv_data->rc = -ENODEV;
231 break;
232
233 default:
234 dev_err(&drv_data->adapter.dev,
235 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
236 "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
237 drv_data->state, status, drv_data->msg->addr,
238 drv_data->msg->flags);
239 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
240 mv64xxx_i2c_hw_init(drv_data);
241 drv_data->rc = -EIO;
242 }
243 }
244
245 static void
246 mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
247 {
248 switch(drv_data->action) {
249 case MV64XXX_I2C_ACTION_SEND_RESTART:
250 drv_data->cntl_bits |= MV64XXX_I2C_REG_CONTROL_START;
251 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
252 writel(drv_data->cntl_bits,
253 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
254 drv_data->block = 0;
255 wake_up_interruptible(&drv_data->waitq);
256 break;
257
258 case MV64XXX_I2C_ACTION_CONTINUE:
259 writel(drv_data->cntl_bits,
260 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
261 break;
262
263 case MV64XXX_I2C_ACTION_SEND_START:
264 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
265 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
266 break;
267
268 case MV64XXX_I2C_ACTION_SEND_ADDR_1:
269 writel(drv_data->addr1,
270 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
271 writel(drv_data->cntl_bits,
272 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
273 break;
274
275 case MV64XXX_I2C_ACTION_SEND_ADDR_2:
276 writel(drv_data->addr2,
277 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
278 writel(drv_data->cntl_bits,
279 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
280 break;
281
282 case MV64XXX_I2C_ACTION_SEND_DATA:
283 writel(drv_data->msg->buf[drv_data->byte_posn++],
284 drv_data->reg_base + MV64XXX_I2C_REG_DATA);
285 writel(drv_data->cntl_bits,
286 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
287 break;
288
289 case MV64XXX_I2C_ACTION_RCV_DATA:
290 drv_data->msg->buf[drv_data->byte_posn++] =
291 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
292 writel(drv_data->cntl_bits,
293 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
294 break;
295
296 case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
297 drv_data->msg->buf[drv_data->byte_posn++] =
298 readl(drv_data->reg_base + MV64XXX_I2C_REG_DATA);
299 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
300 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
301 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
302 drv_data->block = 0;
303 wake_up_interruptible(&drv_data->waitq);
304 break;
305
306 case MV64XXX_I2C_ACTION_INVALID:
307 default:
308 dev_err(&drv_data->adapter.dev,
309 "mv64xxx_i2c_do_action: Invalid action: %d\n",
310 drv_data->action);
311 drv_data->rc = -EIO;
312 /* FALLTHRU */
313 case MV64XXX_I2C_ACTION_SEND_STOP:
314 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
315 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
316 drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
317 drv_data->block = 0;
318 wake_up_interruptible(&drv_data->waitq);
319 break;
320 }
321 }
322
323 static irqreturn_t
324 mv64xxx_i2c_intr(int irq, void *dev_id)
325 {
326 struct mv64xxx_i2c_data *drv_data = dev_id;
327 unsigned long flags;
328 u32 status;
329 irqreturn_t rc = IRQ_NONE;
330
331 spin_lock_irqsave(&drv_data->lock, flags);
332 while (readl(drv_data->reg_base + MV64XXX_I2C_REG_CONTROL) &
333 MV64XXX_I2C_REG_CONTROL_IFLG) {
334 status = readl(drv_data->reg_base + MV64XXX_I2C_REG_STATUS);
335 mv64xxx_i2c_fsm(drv_data, status);
336 mv64xxx_i2c_do_action(drv_data);
337 rc = IRQ_HANDLED;
338 }
339 spin_unlock_irqrestore(&drv_data->lock, flags);
340
341 return rc;
342 }
343
344 /*
345 *****************************************************************************
346 *
347 * I2C Msg Execution Routines
348 *
349 *****************************************************************************
350 */
351 static void
352 mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
353 struct i2c_msg *msg)
354 {
355 u32 dir = 0;
356
357 drv_data->msg = msg;
358 drv_data->byte_posn = 0;
359 drv_data->bytes_left = msg->len;
360 drv_data->aborting = 0;
361 drv_data->rc = 0;
362 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
363 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
364
365 if (msg->flags & I2C_M_RD)
366 dir = 1;
367
368 if (msg->flags & I2C_M_TEN) {
369 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
370 drv_data->addr2 = (u32)msg->addr & 0xff;
371 } else {
372 drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
373 drv_data->addr2 = 0;
374 }
375 }
376
377 static void
378 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
379 {
380 long time_left;
381 unsigned long flags;
382 char abort = 0;
383
384 time_left = wait_event_interruptible_timeout(drv_data->waitq,
385 !drv_data->block, drv_data->adapter.timeout);
386
387 spin_lock_irqsave(&drv_data->lock, flags);
388 if (!time_left) { /* Timed out */
389 drv_data->rc = -ETIMEDOUT;
390 abort = 1;
391 } else if (time_left < 0) { /* Interrupted/Error */
392 drv_data->rc = time_left; /* errno value */
393 abort = 1;
394 }
395
396 if (abort && drv_data->block) {
397 drv_data->aborting = 1;
398 spin_unlock_irqrestore(&drv_data->lock, flags);
399
400 time_left = wait_event_timeout(drv_data->waitq,
401 !drv_data->block, drv_data->adapter.timeout);
402
403 if ((time_left <= 0) && drv_data->block) {
404 drv_data->state = MV64XXX_I2C_STATE_IDLE;
405 dev_err(&drv_data->adapter.dev,
406 "mv64xxx: I2C bus locked, block: %d, "
407 "time_left: %d\n", drv_data->block,
408 (int)time_left);
409 mv64xxx_i2c_hw_init(drv_data);
410 }
411 } else
412 spin_unlock_irqrestore(&drv_data->lock, flags);
413 }
414
415 static int
416 mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
417 int is_first, int is_last)
418 {
419 unsigned long flags;
420
421 spin_lock_irqsave(&drv_data->lock, flags);
422 mv64xxx_i2c_prepare_for_io(drv_data, msg);
423
424 if (unlikely(msg->flags & I2C_M_NOSTART)) { /* Skip start/addr phases */
425 if (drv_data->msg->flags & I2C_M_RD) {
426 /* No action to do, wait for slave to send a byte */
427 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
428 drv_data->state =
429 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
430 } else {
431 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
432 drv_data->state =
433 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
434 drv_data->bytes_left--;
435 }
436 } else {
437 if (is_first) {
438 drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
439 drv_data->state =
440 MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
441 } else {
442 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
443 drv_data->state =
444 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
445 }
446 }
447
448 drv_data->send_stop = is_last;
449 drv_data->block = 1;
450 mv64xxx_i2c_do_action(drv_data);
451 spin_unlock_irqrestore(&drv_data->lock, flags);
452
453 mv64xxx_i2c_wait_for_completion(drv_data);
454 return drv_data->rc;
455 }
456
457 /*
458 *****************************************************************************
459 *
460 * I2C Core Support Routines (Interface to higher level I2C code)
461 *
462 *****************************************************************************
463 */
464 static u32
465 mv64xxx_i2c_functionality(struct i2c_adapter *adap)
466 {
467 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
468 }
469
470 static int
471 mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
472 {
473 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
474 int i, rc;
475
476 for (i = 0; i < num; i++) {
477 rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[i],
478 i == 0, i + 1 == num);
479 if (rc < 0)
480 return rc;
481 }
482
483 return num;
484 }
485
486 static const struct i2c_algorithm mv64xxx_i2c_algo = {
487 .master_xfer = mv64xxx_i2c_xfer,
488 .functionality = mv64xxx_i2c_functionality,
489 };
490
491 /*
492 *****************************************************************************
493 *
494 * Driver Interface & Early Init Routines
495 *
496 *****************************************************************************
497 */
498 static int
499 mv64xxx_i2c_map_regs(struct platform_device *pd,
500 struct mv64xxx_i2c_data *drv_data)
501 {
502 int size;
503 struct resource *r = platform_get_resource(pd, IORESOURCE_MEM, 0);
504
505 if (!r)
506 return -ENODEV;
507
508 size = resource_size(r);
509
510 if (!request_mem_region(r->start, size, drv_data->adapter.name))
511 return -EBUSY;
512
513 drv_data->reg_base = ioremap(r->start, size);
514 drv_data->reg_base_p = r->start;
515 drv_data->reg_size = size;
516
517 return 0;
518 }
519
520 static void
521 mv64xxx_i2c_unmap_regs(struct mv64xxx_i2c_data *drv_data)
522 {
523 if (drv_data->reg_base) {
524 iounmap(drv_data->reg_base);
525 release_mem_region(drv_data->reg_base_p, drv_data->reg_size);
526 }
527
528 drv_data->reg_base = NULL;
529 drv_data->reg_base_p = 0;
530 }
531
532 #ifdef CONFIG_OF
533 static int
534 mv64xxx_calc_freq(const int tclk, const int n, const int m)
535 {
536 return tclk / (10 * (m + 1) * (2 << n));
537 }
538
539 static bool
540 mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n,
541 u32 *best_m)
542 {
543 int freq, delta, best_delta = INT_MAX;
544 int m, n;
545
546 for (n = 0; n <= 7; n++)
547 for (m = 0; m <= 15; m++) {
548 freq = mv64xxx_calc_freq(tclk, n, m);
549 delta = req_freq - freq;
550 if (delta >= 0 && delta < best_delta) {
551 *best_m = m;
552 *best_n = n;
553 best_delta = delta;
554 }
555 if (best_delta == 0)
556 return true;
557 }
558 if (best_delta == INT_MAX)
559 return false;
560 return true;
561 }
562
563 static int
564 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
565 struct device_node *np)
566 {
567 u32 bus_freq, tclk;
568 int rc = 0;
569
570 /* CLK is mandatory when using DT to describe the i2c bus. We
571 * need to know tclk in order to calculate bus clock
572 * factors.
573 */
574 #if !defined(CONFIG_HAVE_CLK)
575 /* Have OF but no CLK */
576 return -ENODEV;
577 #else
578 if (IS_ERR(drv_data->clk)) {
579 rc = -ENODEV;
580 goto out;
581 }
582 tclk = clk_get_rate(drv_data->clk);
583 of_property_read_u32(np, "clock-frequency", &bus_freq);
584 if (!mv64xxx_find_baud_factors(bus_freq, tclk,
585 &drv_data->freq_n, &drv_data->freq_m)) {
586 rc = -EINVAL;
587 goto out;
588 }
589 drv_data->irq = irq_of_parse_and_map(np, 0);
590
591 /* Its not yet defined how timeouts will be specified in device tree.
592 * So hard code the value to 1 second.
593 */
594 drv_data->adapter.timeout = HZ;
595 out:
596 return rc;
597 #endif
598 }
599 #else /* CONFIG_OF */
600 static int
601 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
602 struct device_node *np)
603 {
604 return -ENODEV;
605 }
606 #endif /* CONFIG_OF */
607
608 static int
609 mv64xxx_i2c_probe(struct platform_device *pd)
610 {
611 struct mv64xxx_i2c_data *drv_data;
612 struct mv64xxx_i2c_pdata *pdata = pd->dev.platform_data;
613 int rc;
614
615 if ((!pdata && !pd->dev.of_node))
616 return -ENODEV;
617
618 drv_data = kzalloc(sizeof(struct mv64xxx_i2c_data), GFP_KERNEL);
619 if (!drv_data)
620 return -ENOMEM;
621
622 if (mv64xxx_i2c_map_regs(pd, drv_data)) {
623 rc = -ENODEV;
624 goto exit_kfree;
625 }
626
627 strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
628 sizeof(drv_data->adapter.name));
629
630 init_waitqueue_head(&drv_data->waitq);
631 spin_lock_init(&drv_data->lock);
632
633 #if defined(CONFIG_HAVE_CLK)
634 /* Not all platforms have a clk */
635 drv_data->clk = clk_get(&pd->dev, NULL);
636 if (!IS_ERR(drv_data->clk)) {
637 clk_prepare(drv_data->clk);
638 clk_enable(drv_data->clk);
639 }
640 #endif
641 if (pdata) {
642 drv_data->freq_m = pdata->freq_m;
643 drv_data->freq_n = pdata->freq_n;
644 drv_data->irq = platform_get_irq(pd, 0);
645 drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
646 } else if (pd->dev.of_node) {
647 rc = mv64xxx_of_config(drv_data, pd->dev.of_node);
648 if (rc)
649 goto exit_unmap_regs;
650 }
651 if (drv_data->irq < 0) {
652 rc = -ENXIO;
653 goto exit_unmap_regs;
654 }
655
656 drv_data->adapter.dev.parent = &pd->dev;
657 drv_data->adapter.algo = &mv64xxx_i2c_algo;
658 drv_data->adapter.owner = THIS_MODULE;
659 drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
660 drv_data->adapter.nr = pd->id;
661 drv_data->adapter.dev.of_node = pd->dev.of_node;
662 platform_set_drvdata(pd, drv_data);
663 i2c_set_adapdata(&drv_data->adapter, drv_data);
664
665 mv64xxx_i2c_hw_init(drv_data);
666
667 if (request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
668 MV64XXX_I2C_CTLR_NAME, drv_data)) {
669 dev_err(&drv_data->adapter.dev,
670 "mv64xxx: Can't register intr handler irq: %d\n",
671 drv_data->irq);
672 rc = -EINVAL;
673 goto exit_unmap_regs;
674 } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
675 dev_err(&drv_data->adapter.dev,
676 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
677 goto exit_free_irq;
678 }
679
680 of_i2c_register_devices(&drv_data->adapter);
681
682 return 0;
683
684 exit_free_irq:
685 free_irq(drv_data->irq, drv_data);
686 exit_unmap_regs:
687 #if defined(CONFIG_HAVE_CLK)
688 /* Not all platforms have a clk */
689 if (!IS_ERR(drv_data->clk)) {
690 clk_disable(drv_data->clk);
691 clk_unprepare(drv_data->clk);
692 }
693 #endif
694 mv64xxx_i2c_unmap_regs(drv_data);
695 exit_kfree:
696 kfree(drv_data);
697 return rc;
698 }
699
700 static int
701 mv64xxx_i2c_remove(struct platform_device *dev)
702 {
703 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
704 int rc;
705
706 rc = i2c_del_adapter(&drv_data->adapter);
707 free_irq(drv_data->irq, drv_data);
708 mv64xxx_i2c_unmap_regs(drv_data);
709 #if defined(CONFIG_HAVE_CLK)
710 /* Not all platforms have a clk */
711 if (!IS_ERR(drv_data->clk)) {
712 clk_disable(drv_data->clk);
713 clk_unprepare(drv_data->clk);
714 }
715 #endif
716 kfree(drv_data);
717
718 return rc;
719 }
720
721 static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
722 { .compatible = "marvell,mv64xxx-i2c", },
723 {}
724 };
725 MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
726
727 static struct platform_driver mv64xxx_i2c_driver = {
728 .probe = mv64xxx_i2c_probe,
729 .remove = mv64xxx_i2c_remove,
730 .driver = {
731 .owner = THIS_MODULE,
732 .name = MV64XXX_I2C_CTLR_NAME,
733 .of_match_table = of_match_ptr(mv64xxx_i2c_of_match_table),
734 },
735 };
736
737 module_platform_driver(mv64xxx_i2c_driver);
738
739 MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
740 MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
741 MODULE_LICENSE("GPL");
Linux with added FPC-III support