1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2012 FUJITSU SEMICONDUCTOR LIMITED
4 */
5
6 #include <linux/acpi.h>
7 #include <linux/clk.h>
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/errno.h>
12 #include <linux/i2c.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21
22 #define WAIT_PCLK(n, rate) \
23 ndelay(DIV_ROUND_UP(DIV_ROUND_UP(1000000000, rate), n) + 10)
24
25 /* I2C register address definitions */
26 #define SYNQUACER_I2C_REG_BSR (0x00 << 2) // Bus Status
27 #define SYNQUACER_I2C_REG_BCR (0x01 << 2) // Bus Control
28 #define SYNQUACER_I2C_REG_CCR (0x02 << 2) // Clock Control
29 #define SYNQUACER_I2C_REG_ADR (0x03 << 2) // Address
30 #define SYNQUACER_I2C_REG_DAR (0x04 << 2) // Data
31 #define SYNQUACER_I2C_REG_CSR (0x05 << 2) // Expansion CS
32 #define SYNQUACER_I2C_REG_FSR (0x06 << 2) // Bus Clock Freq
33 #define SYNQUACER_I2C_REG_BC2R (0x07 << 2) // Bus Control 2
34
35 /* I2C register bit definitions */
36 #define SYNQUACER_I2C_BSR_FBT BIT(0) // First Byte Transfer
37 #define SYNQUACER_I2C_BSR_GCA BIT(1) // General Call Address
38 #define SYNQUACER_I2C_BSR_AAS BIT(2) // Address as Slave
39 #define SYNQUACER_I2C_BSR_TRX BIT(3) // Transfer/Receive
40 #define SYNQUACER_I2C_BSR_LRB BIT(4) // Last Received Bit
41 #define SYNQUACER_I2C_BSR_AL BIT(5) // Arbitration Lost
42 #define SYNQUACER_I2C_BSR_RSC BIT(6) // Repeated Start Cond.
43 #define SYNQUACER_I2C_BSR_BB BIT(7) // Bus Busy
44
45 #define SYNQUACER_I2C_BCR_INT BIT(0) // Interrupt
46 #define SYNQUACER_I2C_BCR_INTE BIT(1) // Interrupt Enable
47 #define SYNQUACER_I2C_BCR_GCAA BIT(2) // Gen. Call Access Ack.
48 #define SYNQUACER_I2C_BCR_ACK BIT(3) // Acknowledge
49 #define SYNQUACER_I2C_BCR_MSS BIT(4) // Master Slave Select
50 #define SYNQUACER_I2C_BCR_SCC BIT(5) // Start Condition Cont.
51 #define SYNQUACER_I2C_BCR_BEIE BIT(6) // Bus Error Int Enable
52 #define SYNQUACER_I2C_BCR_BER BIT(7) // Bus Error
53
54 #define SYNQUACER_I2C_CCR_CS_MASK (0x1f) // CCR Clock Period Sel.
55 #define SYNQUACER_I2C_CCR_EN BIT(5) // Enable
56 #define SYNQUACER_I2C_CCR_FM BIT(6) // Speed Mode Select
57
58 #define SYNQUACER_I2C_CSR_CS_MASK (0x3f) // CSR Clock Period Sel.
59
60 #define SYNQUACER_I2C_BC2R_SCLL BIT(0) // SCL Low Drive
61 #define SYNQUACER_I2C_BC2R_SDAL BIT(1) // SDA Low Drive
62 #define SYNQUACER_I2C_BC2R_SCLS BIT(4) // SCL Status
63 #define SYNQUACER_I2C_BC2R_SDAS BIT(5) // SDA Status
64
65 /* PCLK frequency */
66 #define SYNQUACER_I2C_BUS_CLK_FR(rate) (((rate) / 20000000) + 1)
67
68 /* STANDARD MODE frequency */
69 #define SYNQUACER_I2C_CLK_MASTER_STD(rate) \
70 DIV_ROUND_UP(DIV_ROUND_UP((rate), I2C_MAX_STANDARD_MODE_FREQ) - 2, 2)
71 /* FAST MODE frequency */
72 #define SYNQUACER_I2C_CLK_MASTER_FAST(rate) \
73 DIV_ROUND_UP((DIV_ROUND_UP((rate), I2C_MAX_FAST_MODE_FREQ) - 2) * 2, 3)
74
75 /* (clkrate <= 18000000) */
76 /* calculate the value of CS bits in CCR register on standard mode */
77 #define SYNQUACER_I2C_CCR_CS_STD_MAX_18M(rate) \
78 ((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 65) \
79 & SYNQUACER_I2C_CCR_CS_MASK)
80
81 /* calculate the value of CS bits in CSR register on standard mode */
82 #define SYNQUACER_I2C_CSR_CS_STD_MAX_18M(rate) 0x00
83
84 /* calculate the value of CS bits in CCR register on fast mode */
85 #define SYNQUACER_I2C_CCR_CS_FAST_MAX_18M(rate) \
86 ((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1) \
87 & SYNQUACER_I2C_CCR_CS_MASK)
88
89 /* calculate the value of CS bits in CSR register on fast mode */
90 #define SYNQUACER_I2C_CSR_CS_FAST_MAX_18M(rate) 0x00
91
92 /* (clkrate > 18000000) */
93 /* calculate the value of CS bits in CCR register on standard mode */
94 #define SYNQUACER_I2C_CCR_CS_STD_MIN_18M(rate) \
95 ((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 1) \
96 & SYNQUACER_I2C_CCR_CS_MASK)
97
98 /* calculate the value of CS bits in CSR register on standard mode */
99 #define SYNQUACER_I2C_CSR_CS_STD_MIN_18M(rate) \
100 (((SYNQUACER_I2C_CLK_MASTER_STD(rate) - 1) >> 5) \
101 & SYNQUACER_I2C_CSR_CS_MASK)
102
103 /* calculate the value of CS bits in CCR register on fast mode */
104 #define SYNQUACER_I2C_CCR_CS_FAST_MIN_18M(rate) \
105 ((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1) \
106 & SYNQUACER_I2C_CCR_CS_MASK)
107
108 /* calculate the value of CS bits in CSR register on fast mode */
109 #define SYNQUACER_I2C_CSR_CS_FAST_MIN_18M(rate) \
110 (((SYNQUACER_I2C_CLK_MASTER_FAST(rate) - 1) >> 5) \
111 & SYNQUACER_I2C_CSR_CS_MASK)
112
113 /* min I2C clock frequency 14M */
114 #define SYNQUACER_I2C_MIN_CLK_RATE (14 * 1000000)
115 /* max I2C clock frequency 200M */
116 #define SYNQUACER_I2C_MAX_CLK_RATE (200 * 1000000)
117 /* I2C clock frequency 18M */
118 #define SYNQUACER_I2C_CLK_RATE_18M (18 * 1000000)
119
120 #define SYNQUACER_I2C_SPEED_FM 400 // Fast Mode
121 #define SYNQUACER_I2C_SPEED_SM 100 // Standard Mode
122
123 enum i2c_state {
124 STATE_IDLE,
125 STATE_START,
126 STATE_READ,
127 STATE_WRITE
128 };
129
130 struct synquacer_i2c {
131 struct completion completion;
132
133 struct i2c_msg *msg;
134 u32 msg_num;
135 u32 msg_idx;
136 u32 msg_ptr;
137
138 int irq;
139 struct device *dev;
140 void __iomem *base;
141 struct clk *pclk;
142 u32 pclkrate;
143 u32 speed_khz;
144 u32 timeout_ms;
145 enum i2c_state state;
146 struct i2c_adapter adapter;
147 };
148
is_lastmsg(struct synquacer_i2c * i2c)149 static inline int is_lastmsg(struct synquacer_i2c *i2c)
150 {
151 return i2c->msg_idx >= (i2c->msg_num - 1);
152 }
153
is_msglast(struct synquacer_i2c * i2c)154 static inline int is_msglast(struct synquacer_i2c *i2c)
155 {
156 return i2c->msg_ptr == (i2c->msg->len - 1);
157 }
158
is_msgend(struct synquacer_i2c * i2c)159 static inline int is_msgend(struct synquacer_i2c *i2c)
160 {
161 return i2c->msg_ptr >= i2c->msg->len;
162 }
163
calc_timeout_ms(struct synquacer_i2c * i2c,struct i2c_msg * msgs,int num)164 static inline unsigned long calc_timeout_ms(struct synquacer_i2c *i2c,
165 struct i2c_msg *msgs,
166 int num)
167 {
168 unsigned long bit_count = 0;
169 int i;
170
171 for (i = 0; i < num; i++, msgs++)
172 bit_count += msgs->len;
173
174 return DIV_ROUND_UP((bit_count * 9 + num * 10) * 3, 200) + 10;
175 }
176
synquacer_i2c_stop(struct synquacer_i2c * i2c,int ret)177 static void synquacer_i2c_stop(struct synquacer_i2c *i2c, int ret)
178 {
179 /*
180 * clear IRQ (INT=0, BER=0)
181 * set Stop Condition (MSS=0)
182 * Interrupt Disable
183 */
184 writeb(0, i2c->base + SYNQUACER_I2C_REG_BCR);
185
186 i2c->state = STATE_IDLE;
187
188 i2c->msg_ptr = 0;
189 i2c->msg = NULL;
190 i2c->msg_idx++;
191 i2c->msg_num = 0;
192 if (ret)
193 i2c->msg_idx = ret;
194
195 complete(&i2c->completion);
196 }
197
synquacer_i2c_hw_init(struct synquacer_i2c * i2c)198 static void synquacer_i2c_hw_init(struct synquacer_i2c *i2c)
199 {
200 unsigned char ccr_cs, csr_cs;
201 u32 rt = i2c->pclkrate;
202
203 /* Set own Address */
204 writeb(0, i2c->base + SYNQUACER_I2C_REG_ADR);
205
206 /* Set PCLK frequency */
207 writeb(SYNQUACER_I2C_BUS_CLK_FR(i2c->pclkrate),
208 i2c->base + SYNQUACER_I2C_REG_FSR);
209
210 switch (i2c->speed_khz) {
211 case SYNQUACER_I2C_SPEED_FM:
212 if (i2c->pclkrate <= SYNQUACER_I2C_CLK_RATE_18M) {
213 ccr_cs = SYNQUACER_I2C_CCR_CS_FAST_MAX_18M(rt);
214 csr_cs = SYNQUACER_I2C_CSR_CS_FAST_MAX_18M(rt);
215 } else {
216 ccr_cs = SYNQUACER_I2C_CCR_CS_FAST_MIN_18M(rt);
217 csr_cs = SYNQUACER_I2C_CSR_CS_FAST_MIN_18M(rt);
218 }
219
220 /* Set Clock and enable, Set fast mode */
221 writeb(ccr_cs | SYNQUACER_I2C_CCR_FM |
222 SYNQUACER_I2C_CCR_EN,
223 i2c->base + SYNQUACER_I2C_REG_CCR);
224 writeb(csr_cs, i2c->base + SYNQUACER_I2C_REG_CSR);
225 break;
226 case SYNQUACER_I2C_SPEED_SM:
227 if (i2c->pclkrate <= SYNQUACER_I2C_CLK_RATE_18M) {
228 ccr_cs = SYNQUACER_I2C_CCR_CS_STD_MAX_18M(rt);
229 csr_cs = SYNQUACER_I2C_CSR_CS_STD_MAX_18M(rt);
230 } else {
231 ccr_cs = SYNQUACER_I2C_CCR_CS_STD_MIN_18M(rt);
232 csr_cs = SYNQUACER_I2C_CSR_CS_STD_MIN_18M(rt);
233 }
234
235 /* Set Clock and enable, Set standard mode */
236 writeb(ccr_cs | SYNQUACER_I2C_CCR_EN,
237 i2c->base + SYNQUACER_I2C_REG_CCR);
238 writeb(csr_cs, i2c->base + SYNQUACER_I2C_REG_CSR);
239 break;
240 default:
241 WARN_ON(1);
242 }
243
244 /* clear IRQ (INT=0, BER=0), Interrupt Disable */
245 writeb(0, i2c->base + SYNQUACER_I2C_REG_BCR);
246 writeb(0, i2c->base + SYNQUACER_I2C_REG_BC2R);
247 }
248
synquacer_i2c_hw_reset(struct synquacer_i2c * i2c)249 static void synquacer_i2c_hw_reset(struct synquacer_i2c *i2c)
250 {
251 /* Disable clock */
252 writeb(0, i2c->base + SYNQUACER_I2C_REG_CCR);
253 writeb(0, i2c->base + SYNQUACER_I2C_REG_CSR);
254
255 WAIT_PCLK(100, i2c->pclkrate);
256 }
257
synquacer_i2c_master_start(struct synquacer_i2c * i2c,struct i2c_msg * pmsg)258 static int synquacer_i2c_master_start(struct synquacer_i2c *i2c,
259 struct i2c_msg *pmsg)
260 {
261 unsigned char bsr, bcr;
262
263 writeb(i2c_8bit_addr_from_msg(pmsg), i2c->base + SYNQUACER_I2C_REG_DAR);
264
265 dev_dbg(i2c->dev, "slave:0x%02x\n", pmsg->addr);
266
267 /* Generate Start Condition */
268 bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
269 bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR);
270 dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr);
271
272 if ((bsr & SYNQUACER_I2C_BSR_BB) &&
273 !(bcr & SYNQUACER_I2C_BCR_MSS)) {
274 dev_dbg(i2c->dev, "bus is busy");
275 return -EBUSY;
276 }
277
278 if (bsr & SYNQUACER_I2C_BSR_BB) { /* Bus is busy */
279 dev_dbg(i2c->dev, "Continuous Start");
280 writeb(bcr | SYNQUACER_I2C_BCR_SCC,
281 i2c->base + SYNQUACER_I2C_REG_BCR);
282 } else {
283 if (bcr & SYNQUACER_I2C_BCR_MSS) {
284 dev_dbg(i2c->dev, "not in master mode");
285 return -EAGAIN;
286 }
287 dev_dbg(i2c->dev, "Start Condition");
288 /* Start Condition + Enable Interrupts */
289 writeb(bcr | SYNQUACER_I2C_BCR_MSS |
290 SYNQUACER_I2C_BCR_INTE | SYNQUACER_I2C_BCR_BEIE,
291 i2c->base + SYNQUACER_I2C_REG_BCR);
292 }
293
294 WAIT_PCLK(10, i2c->pclkrate);
295
296 /* get BSR & BCR registers */
297 bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
298 bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR);
299 dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr);
300
301 if ((bsr & SYNQUACER_I2C_BSR_AL) ||
302 !(bcr & SYNQUACER_I2C_BCR_MSS)) {
303 dev_dbg(i2c->dev, "arbitration lost\n");
304 return -EAGAIN;
305 }
306
307 return 0;
308 }
309
synquacer_i2c_doxfer(struct synquacer_i2c * i2c,struct i2c_msg * msgs,int num)310 static int synquacer_i2c_doxfer(struct synquacer_i2c *i2c,
311 struct i2c_msg *msgs, int num)
312 {
313 unsigned char bsr;
314 unsigned long timeout;
315 int ret;
316
317 synquacer_i2c_hw_init(i2c);
318 bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
319 if (bsr & SYNQUACER_I2C_BSR_BB) {
320 dev_err(i2c->dev, "cannot get bus (bus busy)\n");
321 return -EBUSY;
322 }
323
324 reinit_completion(&i2c->completion);
325
326 i2c->msg = msgs;
327 i2c->msg_num = num;
328 i2c->msg_ptr = 0;
329 i2c->msg_idx = 0;
330 i2c->state = STATE_START;
331
332 ret = synquacer_i2c_master_start(i2c, i2c->msg);
333 if (ret < 0) {
334 dev_dbg(i2c->dev, "Address failed: (%d)\n", ret);
335 return ret;
336 }
337
338 timeout = wait_for_completion_timeout(&i2c->completion,
339 msecs_to_jiffies(i2c->timeout_ms));
340 if (timeout == 0) {
341 dev_dbg(i2c->dev, "timeout\n");
342 return -EAGAIN;
343 }
344
345 ret = i2c->msg_idx;
346 if (ret != num) {
347 dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
348 return -EAGAIN;
349 }
350
351 /* wait 2 clock periods to ensure the stop has been through the bus */
352 udelay(DIV_ROUND_UP(2 * 1000, i2c->speed_khz));
353
354 return ret;
355 }
356
synquacer_i2c_isr(int irq,void * dev_id)357 static irqreturn_t synquacer_i2c_isr(int irq, void *dev_id)
358 {
359 struct synquacer_i2c *i2c = dev_id;
360
361 unsigned char byte;
362 unsigned char bsr, bcr;
363 int ret;
364
365 bcr = readb(i2c->base + SYNQUACER_I2C_REG_BCR);
366 bsr = readb(i2c->base + SYNQUACER_I2C_REG_BSR);
367 dev_dbg(i2c->dev, "bsr:0x%02x, bcr:0x%02x\n", bsr, bcr);
368
369 if (bcr & SYNQUACER_I2C_BCR_BER) {
370 dev_err(i2c->dev, "bus error\n");
371 synquacer_i2c_stop(i2c, -EAGAIN);
372 goto out;
373 }
374 if ((bsr & SYNQUACER_I2C_BSR_AL) ||
375 !(bcr & SYNQUACER_I2C_BCR_MSS)) {
376 dev_dbg(i2c->dev, "arbitration lost\n");
377 synquacer_i2c_stop(i2c, -EAGAIN);
378 goto out;
379 }
380
381 switch (i2c->state) {
382 case STATE_START:
383 if (bsr & SYNQUACER_I2C_BSR_LRB) {
384 dev_dbg(i2c->dev, "ack was not received\n");
385 synquacer_i2c_stop(i2c, -EAGAIN);
386 goto out;
387 }
388
389 if (i2c->msg->flags & I2C_M_RD)
390 i2c->state = STATE_READ;
391 else
392 i2c->state = STATE_WRITE;
393
394 if (is_lastmsg(i2c) && i2c->msg->len == 0) {
395 synquacer_i2c_stop(i2c, 0);
396 goto out;
397 }
398
399 if (i2c->state == STATE_READ)
400 goto prepare_read;
401 fallthrough;
402
403 case STATE_WRITE:
404 if (bsr & SYNQUACER_I2C_BSR_LRB) {
405 dev_dbg(i2c->dev, "WRITE: No Ack\n");
406 synquacer_i2c_stop(i2c, -EAGAIN);
407 goto out;
408 }
409
410 if (!is_msgend(i2c)) {
411 writeb(i2c->msg->buf[i2c->msg_ptr++],
412 i2c->base + SYNQUACER_I2C_REG_DAR);
413
414 /* clear IRQ, and continue */
415 writeb(SYNQUACER_I2C_BCR_BEIE |
416 SYNQUACER_I2C_BCR_MSS |
417 SYNQUACER_I2C_BCR_INTE,
418 i2c->base + SYNQUACER_I2C_REG_BCR);
419 break;
420 }
421 if (is_lastmsg(i2c)) {
422 synquacer_i2c_stop(i2c, 0);
423 break;
424 }
425 dev_dbg(i2c->dev, "WRITE: Next Message\n");
426
427 i2c->msg_ptr = 0;
428 i2c->msg_idx++;
429 i2c->msg++;
430
431 /* send the new start */
432 ret = synquacer_i2c_master_start(i2c, i2c->msg);
433 if (ret < 0) {
434 dev_dbg(i2c->dev, "restart error (%d)\n", ret);
435 synquacer_i2c_stop(i2c, -EAGAIN);
436 break;
437 }
438 i2c->state = STATE_START;
439 break;
440
441 case STATE_READ:
442 byte = readb(i2c->base + SYNQUACER_I2C_REG_DAR);
443 if (!(bsr & SYNQUACER_I2C_BSR_FBT)) /* data */
444 i2c->msg->buf[i2c->msg_ptr++] = byte;
445 else /* address */
446 dev_dbg(i2c->dev, "address:0x%02x. ignore it.\n", byte);
447
448 prepare_read:
449 if (is_msglast(i2c)) {
450 writeb(SYNQUACER_I2C_BCR_MSS |
451 SYNQUACER_I2C_BCR_BEIE |
452 SYNQUACER_I2C_BCR_INTE,
453 i2c->base + SYNQUACER_I2C_REG_BCR);
454 break;
455 }
456 if (!is_msgend(i2c)) {
457 writeb(SYNQUACER_I2C_BCR_MSS |
458 SYNQUACER_I2C_BCR_BEIE |
459 SYNQUACER_I2C_BCR_INTE |
460 SYNQUACER_I2C_BCR_ACK,
461 i2c->base + SYNQUACER_I2C_REG_BCR);
462 break;
463 }
464 if (is_lastmsg(i2c)) {
465 /* last message, send stop and complete */
466 dev_dbg(i2c->dev, "READ: Send Stop\n");
467 synquacer_i2c_stop(i2c, 0);
468 break;
469 }
470 dev_dbg(i2c->dev, "READ: Next Transfer\n");
471
472 i2c->msg_ptr = 0;
473 i2c->msg_idx++;
474 i2c->msg++;
475
476 ret = synquacer_i2c_master_start(i2c, i2c->msg);
477 if (ret < 0) {
478 dev_dbg(i2c->dev, "restart error (%d)\n", ret);
479 synquacer_i2c_stop(i2c, -EAGAIN);
480 } else {
481 i2c->state = STATE_START;
482 }
483 break;
484 default:
485 dev_err(i2c->dev, "called in err STATE (%d)\n", i2c->state);
486 break;
487 }
488
489 out:
490 WAIT_PCLK(10, i2c->pclkrate);
491 return IRQ_HANDLED;
492 }
493
synquacer_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)494 static int synquacer_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
495 int num)
496 {
497 struct synquacer_i2c *i2c;
498 int retry;
499 int ret;
500
501 i2c = i2c_get_adapdata(adap);
502 i2c->timeout_ms = calc_timeout_ms(i2c, msgs, num);
503
504 dev_dbg(i2c->dev, "calculated timeout %d ms\n", i2c->timeout_ms);
505
506 for (retry = 0; retry <= adap->retries; retry++) {
507 ret = synquacer_i2c_doxfer(i2c, msgs, num);
508 if (ret != -EAGAIN)
509 return ret;
510
511 dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
512
513 synquacer_i2c_hw_reset(i2c);
514 }
515 return -EIO;
516 }
517
synquacer_i2c_functionality(struct i2c_adapter * adap)518 static u32 synquacer_i2c_functionality(struct i2c_adapter *adap)
519 {
520 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
521 }
522
523 static const struct i2c_algorithm synquacer_i2c_algo = {
524 .master_xfer = synquacer_i2c_xfer,
525 .functionality = synquacer_i2c_functionality,
526 };
527
528 static const struct i2c_adapter synquacer_i2c_ops = {
529 .owner = THIS_MODULE,
530 .name = "synquacer_i2c-adapter",
531 .algo = &synquacer_i2c_algo,
532 .retries = 5,
533 };
534
synquacer_i2c_probe(struct platform_device * pdev)535 static int synquacer_i2c_probe(struct platform_device *pdev)
536 {
537 struct synquacer_i2c *i2c;
538 u32 bus_speed;
539 int ret;
540
541 i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
542 if (!i2c)
543 return -ENOMEM;
544
545 bus_speed = i2c_acpi_find_bus_speed(&pdev->dev);
546 if (!bus_speed)
547 device_property_read_u32(&pdev->dev, "clock-frequency",
548 &bus_speed);
549
550 device_property_read_u32(&pdev->dev, "socionext,pclk-rate",
551 &i2c->pclkrate);
552
553 i2c->pclk = devm_clk_get(&pdev->dev, "pclk");
554 if (PTR_ERR(i2c->pclk) == -EPROBE_DEFER)
555 return -EPROBE_DEFER;
556 if (!IS_ERR_OR_NULL(i2c->pclk)) {
557 dev_dbg(&pdev->dev, "clock source %p\n", i2c->pclk);
558
559 ret = clk_prepare_enable(i2c->pclk);
560 if (ret) {
561 dev_err(&pdev->dev, "failed to enable clock (%d)\n",
562 ret);
563 return ret;
564 }
565 i2c->pclkrate = clk_get_rate(i2c->pclk);
566 }
567
568 if (i2c->pclkrate < SYNQUACER_I2C_MIN_CLK_RATE ||
569 i2c->pclkrate > SYNQUACER_I2C_MAX_CLK_RATE) {
570 dev_err(&pdev->dev, "PCLK missing or out of range (%d)\n",
571 i2c->pclkrate);
572 return -EINVAL;
573 }
574
575 i2c->base = devm_platform_ioremap_resource(pdev, 0);
576 if (IS_ERR(i2c->base))
577 return PTR_ERR(i2c->base);
578
579 i2c->irq = platform_get_irq(pdev, 0);
580 if (i2c->irq < 0)
581 return i2c->irq;
582
583 ret = devm_request_irq(&pdev->dev, i2c->irq, synquacer_i2c_isr,
584 0, dev_name(&pdev->dev), i2c);
585 if (ret < 0) {
586 dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
587 return ret;
588 }
589
590 i2c->state = STATE_IDLE;
591 i2c->dev = &pdev->dev;
592 i2c->adapter = synquacer_i2c_ops;
593 i2c_set_adapdata(&i2c->adapter, i2c);
594 i2c->adapter.dev.parent = &pdev->dev;
595 i2c->adapter.dev.of_node = pdev->dev.of_node;
596 ACPI_COMPANION_SET(&i2c->adapter.dev, ACPI_COMPANION(&pdev->dev));
597 i2c->adapter.nr = pdev->id;
598 init_completion(&i2c->completion);
599
600 if (bus_speed < I2C_MAX_FAST_MODE_FREQ)
601 i2c->speed_khz = SYNQUACER_I2C_SPEED_SM;
602 else
603 i2c->speed_khz = SYNQUACER_I2C_SPEED_FM;
604
605 synquacer_i2c_hw_init(i2c);
606
607 ret = i2c_add_numbered_adapter(&i2c->adapter);
608 if (ret) {
609 dev_err(&pdev->dev, "failed to add bus to i2c core\n");
610 return ret;
611 }
612
613 platform_set_drvdata(pdev, i2c);
614
615 dev_info(&pdev->dev, "%s: synquacer_i2c adapter\n",
616 dev_name(&i2c->adapter.dev));
617
618 return 0;
619 }
620
synquacer_i2c_remove(struct platform_device * pdev)621 static int synquacer_i2c_remove(struct platform_device *pdev)
622 {
623 struct synquacer_i2c *i2c = platform_get_drvdata(pdev);
624
625 i2c_del_adapter(&i2c->adapter);
626 if (!IS_ERR(i2c->pclk))
627 clk_disable_unprepare(i2c->pclk);
628
629 return 0;
630 };
631
632 static const struct of_device_id synquacer_i2c_dt_ids[] = {
633 { .compatible = "socionext,synquacer-i2c" },
634 { /* sentinel */ }
635 };
636 MODULE_DEVICE_TABLE(of, synquacer_i2c_dt_ids);
637
638 #ifdef CONFIG_ACPI
639 static const struct acpi_device_id synquacer_i2c_acpi_ids[] = {
640 { "SCX0003" },
641 { /* sentinel */ }
642 };
643 MODULE_DEVICE_TABLE(acpi, synquacer_i2c_acpi_ids);
644 #endif
645
646 static struct platform_driver synquacer_i2c_driver = {
647 .probe = synquacer_i2c_probe,
648 .remove = synquacer_i2c_remove,
649 .driver = {
650 .name = "synquacer_i2c",
651 .of_match_table = of_match_ptr(synquacer_i2c_dt_ids),
652 .acpi_match_table = ACPI_PTR(synquacer_i2c_acpi_ids),
653 },
654 };
655 module_platform_driver(synquacer_i2c_driver);
656
657 MODULE_AUTHOR("Fujitsu Semiconductor Ltd");
658 MODULE_DESCRIPTION("Socionext SynQuacer I2C Driver");
659 MODULE_LICENSE("GPL v2");
660