1 /*
2 * Ingenic JZ4780 I2C bus driver
3 *
4 * Copyright (C) 2006 - 2009 Ingenic Semiconductor Inc.
5 * Copyright (C) 2015 Imagination Technologies
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18 #include <linux/bitops.h>
19 #include <linux/clk.h>
20 #include <linux/completion.h>
21 #include <linux/delay.h>
22 #include <linux/errno.h>
23 #include <linux/i2c.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/io.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/platform_device.h>
30 #include <linux/sched.h>
31 #include <linux/slab.h>
32 #include <linux/time.h>
33
34 #define JZ4780_I2C_CTRL 0x00
35 #define JZ4780_I2C_TAR 0x04
36 #define JZ4780_I2C_SAR 0x08
37 #define JZ4780_I2C_DC 0x10
38 #define JZ4780_I2C_SHCNT 0x14
39 #define JZ4780_I2C_SLCNT 0x18
40 #define JZ4780_I2C_FHCNT 0x1C
41 #define JZ4780_I2C_FLCNT 0x20
42 #define JZ4780_I2C_INTST 0x2C
43 #define JZ4780_I2C_INTM 0x30
44 #define JZ4780_I2C_RXTL 0x38
45 #define JZ4780_I2C_TXTL 0x3C
46 #define JZ4780_I2C_CINTR 0x40
47 #define JZ4780_I2C_CRXUF 0x44
48 #define JZ4780_I2C_CRXOF 0x48
49 #define JZ4780_I2C_CTXOF 0x4C
50 #define JZ4780_I2C_CRXREQ 0x50
51 #define JZ4780_I2C_CTXABRT 0x54
52 #define JZ4780_I2C_CRXDONE 0x58
53 #define JZ4780_I2C_CACT 0x5C
54 #define JZ4780_I2C_CSTP 0x60
55 #define JZ4780_I2C_CSTT 0x64
56 #define JZ4780_I2C_CGC 0x68
57 #define JZ4780_I2C_ENB 0x6C
58 #define JZ4780_I2C_STA 0x70
59 #define JZ4780_I2C_TXABRT 0x80
60 #define JZ4780_I2C_DMACR 0x88
61 #define JZ4780_I2C_DMATDLR 0x8C
62 #define JZ4780_I2C_DMARDLR 0x90
63 #define JZ4780_I2C_SDASU 0x94
64 #define JZ4780_I2C_ACKGC 0x98
65 #define JZ4780_I2C_ENSTA 0x9C
66 #define JZ4780_I2C_SDAHD 0xD0
67
68 #define JZ4780_I2C_CTRL_STPHLD BIT(7)
69 #define JZ4780_I2C_CTRL_SLVDIS BIT(6)
70 #define JZ4780_I2C_CTRL_REST BIT(5)
71 #define JZ4780_I2C_CTRL_MATP BIT(4)
72 #define JZ4780_I2C_CTRL_SATP BIT(3)
73 #define JZ4780_I2C_CTRL_SPDF BIT(2)
74 #define JZ4780_I2C_CTRL_SPDS BIT(1)
75 #define JZ4780_I2C_CTRL_MD BIT(0)
76
77 #define JZ4780_I2C_STA_SLVACT BIT(6)
78 #define JZ4780_I2C_STA_MSTACT BIT(5)
79 #define JZ4780_I2C_STA_RFF BIT(4)
80 #define JZ4780_I2C_STA_RFNE BIT(3)
81 #define JZ4780_I2C_STA_TFE BIT(2)
82 #define JZ4780_I2C_STA_TFNF BIT(1)
83 #define JZ4780_I2C_STA_ACT BIT(0)
84
85 #define JZ4780_I2C_INTST_IGC BIT(11)
86 #define JZ4780_I2C_INTST_ISTT BIT(10)
87 #define JZ4780_I2C_INTST_ISTP BIT(9)
88 #define JZ4780_I2C_INTST_IACT BIT(8)
89 #define JZ4780_I2C_INTST_RXDN BIT(7)
90 #define JZ4780_I2C_INTST_TXABT BIT(6)
91 #define JZ4780_I2C_INTST_RDREQ BIT(5)
92 #define JZ4780_I2C_INTST_TXEMP BIT(4)
93 #define JZ4780_I2C_INTST_TXOF BIT(3)
94 #define JZ4780_I2C_INTST_RXFL BIT(2)
95 #define JZ4780_I2C_INTST_RXOF BIT(1)
96 #define JZ4780_I2C_INTST_RXUF BIT(0)
97
98 #define JZ4780_I2C_INTM_MIGC BIT(11)
99 #define JZ4780_I2C_INTM_MISTT BIT(10)
100 #define JZ4780_I2C_INTM_MISTP BIT(9)
101 #define JZ4780_I2C_INTM_MIACT BIT(8)
102 #define JZ4780_I2C_INTM_MRXDN BIT(7)
103 #define JZ4780_I2C_INTM_MTXABT BIT(6)
104 #define JZ4780_I2C_INTM_MRDREQ BIT(5)
105 #define JZ4780_I2C_INTM_MTXEMP BIT(4)
106 #define JZ4780_I2C_INTM_MTXOF BIT(3)
107 #define JZ4780_I2C_INTM_MRXFL BIT(2)
108 #define JZ4780_I2C_INTM_MRXOF BIT(1)
109 #define JZ4780_I2C_INTM_MRXUF BIT(0)
110
111 #define JZ4780_I2C_DC_READ BIT(8)
112
113 #define JZ4780_I2C_SDAHD_HDENB BIT(8)
114
115 #define JZ4780_I2C_ENB_I2C BIT(0)
116
117 #define JZ4780_I2CSHCNT_ADJUST(n) (((n) - 8) < 6 ? 6 : ((n) - 8))
118 #define JZ4780_I2CSLCNT_ADJUST(n) (((n) - 1) < 8 ? 8 : ((n) - 1))
119 #define JZ4780_I2CFHCNT_ADJUST(n) (((n) - 8) < 6 ? 6 : ((n) - 8))
120 #define JZ4780_I2CFLCNT_ADJUST(n) (((n) - 1) < 8 ? 8 : ((n) - 1))
121
122 #define JZ4780_I2C_FIFO_LEN 16
123 #define TX_LEVEL 3
124 #define RX_LEVEL (JZ4780_I2C_FIFO_LEN - TX_LEVEL - 1)
125
126 #define JZ4780_I2C_TIMEOUT 300
127
128 #define BUFSIZE 200
129
130 struct jz4780_i2c {
131 void __iomem *iomem;
132 int irq;
133 struct clk *clk;
134 struct i2c_adapter adap;
135
136 /* lock to protect rbuf and wbuf between xfer_rd/wr and irq handler */
137 spinlock_t lock;
138
139 /* beginning of lock scope */
140 unsigned char *rbuf;
141 int rd_total_len;
142 int rd_data_xfered;
143 int rd_cmd_xfered;
144
145 unsigned char *wbuf;
146 int wt_len;
147
148 int is_write;
149 int stop_hold;
150 int speed;
151
152 int data_buf[BUFSIZE];
153 int cmd_buf[BUFSIZE];
154 int cmd;
155
156 /* end of lock scope */
157 struct completion trans_waitq;
158 };
159
jz4780_i2c_readw(struct jz4780_i2c * i2c,unsigned long offset)160 static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c,
161 unsigned long offset)
162 {
163 return readw(i2c->iomem + offset);
164 }
165
jz4780_i2c_writew(struct jz4780_i2c * i2c,unsigned long offset,unsigned short val)166 static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c,
167 unsigned long offset, unsigned short val)
168 {
169 writew(val, i2c->iomem + offset);
170 }
171
jz4780_i2c_disable(struct jz4780_i2c * i2c)172 static int jz4780_i2c_disable(struct jz4780_i2c *i2c)
173 {
174 unsigned short regval;
175 unsigned long loops = 5;
176
177 jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0);
178
179 do {
180 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
181 if (!(regval & JZ4780_I2C_ENB_I2C))
182 return 0;
183
184 usleep_range(5000, 15000);
185 } while (--loops);
186
187 dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval);
188 return -ETIMEDOUT;
189 }
190
jz4780_i2c_enable(struct jz4780_i2c * i2c)191 static int jz4780_i2c_enable(struct jz4780_i2c *i2c)
192 {
193 unsigned short regval;
194 unsigned long loops = 5;
195
196 jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1);
197
198 do {
199 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
200 if (regval & JZ4780_I2C_ENB_I2C)
201 return 0;
202
203 usleep_range(5000, 15000);
204 } while (--loops);
205
206 dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval);
207 return -ETIMEDOUT;
208 }
209
jz4780_i2c_set_target(struct jz4780_i2c * i2c,unsigned char address)210 static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address)
211 {
212 unsigned short regval;
213 unsigned long loops = 5;
214
215 do {
216 regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
217 if ((regval & JZ4780_I2C_STA_TFE) &&
218 !(regval & JZ4780_I2C_STA_MSTACT))
219 break;
220
221 usleep_range(5000, 15000);
222 } while (--loops);
223
224 if (loops) {
225 jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address);
226 return 0;
227 }
228
229 dev_err(&i2c->adap.dev,
230 "set device to address 0x%02x failed, STA=0x%04x\n",
231 address, regval);
232
233 return -ENXIO;
234 }
235
jz4780_i2c_set_speed(struct jz4780_i2c * i2c)236 static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c)
237 {
238 int dev_clk_khz = clk_get_rate(i2c->clk) / 1000;
239 int cnt_high = 0; /* HIGH period count of the SCL clock */
240 int cnt_low = 0; /* LOW period count of the SCL clock */
241 int cnt_period = 0; /* period count of the SCL clock */
242 int setup_time = 0;
243 int hold_time = 0;
244 unsigned short tmp = 0;
245 int i2c_clk = i2c->speed;
246
247 if (jz4780_i2c_disable(i2c))
248 dev_dbg(&i2c->adap.dev, "i2c not disabled\n");
249
250 /*
251 * 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk)
252 * standard mode, min LOW and HIGH period are 4700 ns and 4000 ns
253 * fast mode, min LOW and HIGH period are 1300 ns and 600 ns
254 */
255 cnt_period = dev_clk_khz / i2c_clk;
256
257 if (i2c_clk <= 100)
258 cnt_high = (cnt_period * 4000) / (4700 + 4000);
259 else
260 cnt_high = (cnt_period * 600) / (1300 + 600);
261
262 cnt_low = cnt_period - cnt_high;
263
264 /*
265 * NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because
266 * normal read are 2 messages, we cannot disable i2c controller
267 * between these two messages, this means that we must always set
268 * JZ4780_I2C_CTRL_REST when init JZ4780_I2C_CTRL
269 *
270 */
271 if (i2c_clk <= 100) {
272 tmp = JZ4780_I2C_CTRL_SPDS | JZ4780_I2C_CTRL_REST
273 | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
274 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
275
276 jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT,
277 JZ4780_I2CSHCNT_ADJUST(cnt_high));
278 jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT,
279 JZ4780_I2CSLCNT_ADJUST(cnt_low));
280 } else {
281 tmp = JZ4780_I2C_CTRL_SPDF | JZ4780_I2C_CTRL_REST
282 | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
283 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
284
285 jz4780_i2c_writew(i2c, JZ4780_I2C_FHCNT,
286 JZ4780_I2CFHCNT_ADJUST(cnt_high));
287 jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT,
288 JZ4780_I2CFLCNT_ADJUST(cnt_low));
289 }
290
291 /*
292 * a i2c device must internally provide a hold time at least 300ns
293 * tHD:DAT
294 * Standard Mode: min=300ns, max=3450ns
295 * Fast Mode: min=0ns, max=900ns
296 * tSU:DAT
297 * Standard Mode: min=250ns, max=infinite
298 * Fast Mode: min=100(250ns is recommended), max=infinite
299 *
300 * 1i2c_clk = 10^6 / dev_clk_khz
301 * on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns
302 * on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns
303 *
304 * The actual hold time is (SDAHD + 1) * (i2c_clk period).
305 *
306 * Length of setup time calculated using (SDASU - 1) * (ic_clk_period)
307 *
308 */
309 if (i2c_clk <= 100) { /* standard mode */
310 setup_time = 300;
311 hold_time = 400;
312 } else {
313 setup_time = 450;
314 hold_time = 450;
315 }
316
317 hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1;
318 setup_time = ((setup_time * dev_clk_khz) / 1000000) + 1;
319
320 if (setup_time > 255)
321 setup_time = 255;
322
323 if (setup_time <= 0)
324 setup_time = 1;
325
326 jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time);
327
328 if (hold_time > 255)
329 hold_time = 255;
330
331 if (hold_time >= 0) {
332 /*i2c hold time enable */
333 hold_time |= JZ4780_I2C_SDAHD_HDENB;
334 jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time);
335 } else {
336 /* disable hold time */
337 jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0);
338 }
339
340 return 0;
341 }
342
jz4780_i2c_cleanup(struct jz4780_i2c * i2c)343 static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c)
344 {
345 int ret;
346 unsigned long flags;
347 unsigned short tmp;
348
349 spin_lock_irqsave(&i2c->lock, flags);
350
351 /* can send stop now if need */
352 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
353 tmp &= ~JZ4780_I2C_CTRL_STPHLD;
354 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
355
356 /* disable all interrupts first */
357 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
358
359 /* then clear all interrupts */
360 jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT);
361 jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR);
362
363 /* then disable the controller */
364 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
365 tmp &= ~JZ4780_I2C_ENB_I2C;
366 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
367 udelay(10);
368 tmp |= JZ4780_I2C_ENB_I2C;
369 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
370
371 spin_unlock_irqrestore(&i2c->lock, flags);
372
373 ret = jz4780_i2c_disable(i2c);
374 if (ret)
375 dev_err(&i2c->adap.dev,
376 "unable to disable device during cleanup!\n");
377
378 if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM)
379 & jz4780_i2c_readw(i2c, JZ4780_I2C_INTST)))
380 dev_err(&i2c->adap.dev,
381 "device has interrupts after a complete cleanup!\n");
382
383 return ret;
384 }
385
jz4780_i2c_prepare(struct jz4780_i2c * i2c)386 static int jz4780_i2c_prepare(struct jz4780_i2c *i2c)
387 {
388 jz4780_i2c_set_speed(i2c);
389 return jz4780_i2c_enable(i2c);
390 }
391
jz4780_i2c_send_rcmd(struct jz4780_i2c * i2c,int cmd_count)392 static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c, int cmd_count)
393 {
394 int i;
395
396 for (i = 0; i < cmd_count; i++)
397 jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
398 }
399
jz4780_i2c_trans_done(struct jz4780_i2c * i2c)400 static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c)
401 {
402 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
403 complete(&i2c->trans_waitq);
404 }
405
jz4780_i2c_irq(int irqno,void * dev_id)406 static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id)
407 {
408 unsigned short tmp;
409 unsigned short intst;
410 unsigned short intmsk;
411 struct jz4780_i2c *i2c = dev_id;
412 unsigned long flags;
413
414 spin_lock_irqsave(&i2c->lock, flags);
415 intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
416 intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST);
417
418 intst &= intmsk;
419
420 if (intst & JZ4780_I2C_INTST_TXABT) {
421 jz4780_i2c_trans_done(i2c);
422 goto done;
423 }
424
425 if (intst & JZ4780_I2C_INTST_RXOF) {
426 dev_dbg(&i2c->adap.dev, "received fifo overflow!\n");
427 jz4780_i2c_trans_done(i2c);
428 goto done;
429 }
430
431 /*
432 * When reading, always drain RX FIFO before we send more Read
433 * Commands to avoid fifo overrun
434 */
435 if (i2c->is_write == 0) {
436 int rd_left;
437
438 while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA)
439 & JZ4780_I2C_STA_RFNE)) {
440 *(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC)
441 & 0xff;
442 i2c->rd_data_xfered++;
443 if (i2c->rd_data_xfered == i2c->rd_total_len) {
444 jz4780_i2c_trans_done(i2c);
445 goto done;
446 }
447 }
448
449 rd_left = i2c->rd_total_len - i2c->rd_data_xfered;
450
451 if (rd_left <= JZ4780_I2C_FIFO_LEN)
452 jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1);
453 }
454
455 if (intst & JZ4780_I2C_INTST_TXEMP) {
456 if (i2c->is_write == 0) {
457 int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
458 int max_send = (JZ4780_I2C_FIFO_LEN - 1)
459 - (i2c->rd_cmd_xfered
460 - i2c->rd_data_xfered);
461 int cmd_to_send = min(cmd_left, max_send);
462
463 if (i2c->rd_cmd_xfered != 0)
464 cmd_to_send = min(cmd_to_send,
465 JZ4780_I2C_FIFO_LEN
466 - TX_LEVEL - 1);
467
468 if (cmd_to_send) {
469 jz4780_i2c_send_rcmd(i2c, cmd_to_send);
470 i2c->rd_cmd_xfered += cmd_to_send;
471 }
472
473 cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
474 if (cmd_left == 0) {
475 intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
476 intmsk &= ~JZ4780_I2C_INTM_MTXEMP;
477 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk);
478
479 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
480 tmp &= ~JZ4780_I2C_CTRL_STPHLD;
481 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
482 }
483 } else {
484 unsigned short data;
485 unsigned short i2c_sta;
486
487 i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
488
489 while ((i2c_sta & JZ4780_I2C_STA_TFNF) &&
490 (i2c->wt_len > 0)) {
491 i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
492 data = *i2c->wbuf;
493 data &= ~JZ4780_I2C_DC_READ;
494 jz4780_i2c_writew(i2c, JZ4780_I2C_DC,
495 data);
496 i2c->wbuf++;
497 i2c->wt_len--;
498 }
499
500 if (i2c->wt_len == 0) {
501 if (!i2c->stop_hold) {
502 tmp = jz4780_i2c_readw(i2c,
503 JZ4780_I2C_CTRL);
504 tmp &= ~JZ4780_I2C_CTRL_STPHLD;
505 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL,
506 tmp);
507 }
508
509 jz4780_i2c_trans_done(i2c);
510 goto done;
511 }
512 }
513 }
514
515 done:
516 spin_unlock_irqrestore(&i2c->lock, flags);
517 return IRQ_HANDLED;
518 }
519
jz4780_i2c_txabrt(struct jz4780_i2c * i2c,int src)520 static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src)
521 {
522 dev_dbg(&i2c->adap.dev, "txabrt: 0x%08x, cmd: %d, send: %d, recv: %d\n",
523 src, i2c->cmd, i2c->cmd_buf[i2c->cmd], i2c->data_buf[i2c->cmd]);
524 }
525
jz4780_i2c_xfer_read(struct jz4780_i2c * i2c,unsigned char * buf,int len,int cnt,int idx)526 static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c,
527 unsigned char *buf, int len, int cnt,
528 int idx)
529 {
530 int ret = 0;
531 long timeout;
532 int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
533 unsigned short tmp;
534 unsigned long flags;
535
536 memset(buf, 0, len);
537
538 spin_lock_irqsave(&i2c->lock, flags);
539
540 i2c->stop_hold = 0;
541 i2c->is_write = 0;
542 i2c->rbuf = buf;
543 i2c->rd_total_len = len;
544 i2c->rd_data_xfered = 0;
545 i2c->rd_cmd_xfered = 0;
546
547 if (len <= JZ4780_I2C_FIFO_LEN)
548 jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1);
549 else
550 jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, RX_LEVEL);
551
552 jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
553
554 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM,
555 JZ4780_I2C_INTM_MRXFL | JZ4780_I2C_INTM_MTXEMP
556 | JZ4780_I2C_INTM_MTXABT | JZ4780_I2C_INTM_MRXOF);
557
558 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
559 tmp |= JZ4780_I2C_CTRL_STPHLD;
560 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
561
562 spin_unlock_irqrestore(&i2c->lock, flags);
563
564 timeout = wait_for_completion_timeout(&i2c->trans_waitq,
565 msecs_to_jiffies(wait_time));
566
567 if (!timeout) {
568 dev_err(&i2c->adap.dev, "irq read timeout\n");
569 dev_dbg(&i2c->adap.dev, "send cmd count:%d %d\n",
570 i2c->cmd, i2c->cmd_buf[i2c->cmd]);
571 dev_dbg(&i2c->adap.dev, "receive data count:%d %d\n",
572 i2c->cmd, i2c->data_buf[i2c->cmd]);
573 ret = -EIO;
574 }
575
576 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
577 if (tmp) {
578 jz4780_i2c_txabrt(i2c, tmp);
579 ret = -EIO;
580 }
581
582 return ret;
583 }
584
jz4780_i2c_xfer_write(struct jz4780_i2c * i2c,unsigned char * buf,int len,int cnt,int idx)585 static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c,
586 unsigned char *buf, int len,
587 int cnt, int idx)
588 {
589 int ret = 0;
590 int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
591 long timeout;
592 unsigned short tmp;
593 unsigned long flags;
594
595 spin_lock_irqsave(&i2c->lock, flags);
596
597 if (idx < (cnt - 1))
598 i2c->stop_hold = 1;
599 else
600 i2c->stop_hold = 0;
601
602 i2c->is_write = 1;
603 i2c->wbuf = buf;
604 i2c->wt_len = len;
605
606 jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, TX_LEVEL);
607
608 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP
609 | JZ4780_I2C_INTM_MTXABT);
610
611 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
612 tmp |= JZ4780_I2C_CTRL_STPHLD;
613 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
614
615 spin_unlock_irqrestore(&i2c->lock, flags);
616
617 timeout = wait_for_completion_timeout(&i2c->trans_waitq,
618 msecs_to_jiffies(wait_time));
619 if (timeout && !i2c->stop_hold) {
620 unsigned short i2c_sta;
621 int write_in_process;
622
623 timeout = JZ4780_I2C_TIMEOUT * 100;
624 for (; timeout > 0; timeout--) {
625 i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
626
627 write_in_process = (i2c_sta & JZ4780_I2C_STA_MSTACT) ||
628 !(i2c_sta & JZ4780_I2C_STA_TFE);
629 if (!write_in_process)
630 break;
631 udelay(10);
632 }
633 }
634
635 if (!timeout) {
636 dev_err(&i2c->adap.dev, "write wait timeout\n");
637 ret = -EIO;
638 }
639
640 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
641 if (tmp) {
642 jz4780_i2c_txabrt(i2c, tmp);
643 ret = -EIO;
644 }
645
646 return ret;
647 }
648
jz4780_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msg,int count)649 static int jz4780_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
650 int count)
651 {
652 int i = -EIO;
653 int ret = 0;
654 struct jz4780_i2c *i2c = adap->algo_data;
655
656 ret = jz4780_i2c_prepare(i2c);
657 if (ret) {
658 dev_err(&i2c->adap.dev, "I2C prepare failed\n");
659 goto out;
660 }
661
662 if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) {
663 ret = jz4780_i2c_set_target(i2c, msg->addr);
664 if (ret)
665 goto out;
666 }
667 for (i = 0; i < count; i++, msg++) {
668 if (msg->flags & I2C_M_RD)
669 ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len,
670 count, i);
671 else
672 ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len,
673 count, i);
674
675 if (ret)
676 goto out;
677 }
678
679 ret = i;
680
681 out:
682 jz4780_i2c_cleanup(i2c);
683 return ret;
684 }
685
jz4780_i2c_functionality(struct i2c_adapter * adap)686 static u32 jz4780_i2c_functionality(struct i2c_adapter *adap)
687 {
688 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
689 }
690
691 static const struct i2c_algorithm jz4780_i2c_algorithm = {
692 .master_xfer = jz4780_i2c_xfer,
693 .functionality = jz4780_i2c_functionality,
694 };
695
696 static const struct of_device_id jz4780_i2c_of_matches[] = {
697 { .compatible = "ingenic,jz4780-i2c", },
698 { /* sentinel */ }
699 };
700 MODULE_DEVICE_TABLE(of, jz4780_i2c_of_matches);
701
jz4780_i2c_probe(struct platform_device * pdev)702 static int jz4780_i2c_probe(struct platform_device *pdev)
703 {
704 int ret = 0;
705 unsigned int clk_freq = 0;
706 unsigned short tmp;
707 struct resource *r;
708 struct jz4780_i2c *i2c;
709
710 i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
711 if (!i2c)
712 return -ENOMEM;
713
714 i2c->adap.owner = THIS_MODULE;
715 i2c->adap.algo = &jz4780_i2c_algorithm;
716 i2c->adap.algo_data = i2c;
717 i2c->adap.retries = 5;
718 i2c->adap.dev.parent = &pdev->dev;
719 i2c->adap.dev.of_node = pdev->dev.of_node;
720 sprintf(i2c->adap.name, "%s", pdev->name);
721
722 init_completion(&i2c->trans_waitq);
723 spin_lock_init(&i2c->lock);
724
725 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
726 i2c->iomem = devm_ioremap_resource(&pdev->dev, r);
727 if (IS_ERR(i2c->iomem))
728 return PTR_ERR(i2c->iomem);
729
730 platform_set_drvdata(pdev, i2c);
731
732 i2c->clk = devm_clk_get(&pdev->dev, NULL);
733 if (IS_ERR(i2c->clk))
734 return PTR_ERR(i2c->clk);
735
736 ret = clk_prepare_enable(i2c->clk);
737 if (ret)
738 return ret;
739
740 ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
741 &clk_freq);
742 if (ret) {
743 dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
744 goto err;
745 }
746
747 i2c->speed = clk_freq / 1000;
748 if (i2c->speed == 0) {
749 ret = -EINVAL;
750 dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
751 goto err;
752 }
753 jz4780_i2c_set_speed(i2c);
754
755 dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);
756
757 tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
758 tmp &= ~JZ4780_I2C_CTRL_STPHLD;
759 jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
760
761 jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0);
762
763 ret = platform_get_irq(pdev, 0);
764 if (ret < 0)
765 goto err;
766 i2c->irq = ret;
767 ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
768 dev_name(&pdev->dev), i2c);
769 if (ret)
770 goto err;
771
772 ret = i2c_add_adapter(&i2c->adap);
773 if (ret < 0)
774 goto err;
775
776 return 0;
777
778 err:
779 clk_disable_unprepare(i2c->clk);
780 return ret;
781 }
782
jz4780_i2c_remove(struct platform_device * pdev)783 static int jz4780_i2c_remove(struct platform_device *pdev)
784 {
785 struct jz4780_i2c *i2c = platform_get_drvdata(pdev);
786
787 clk_disable_unprepare(i2c->clk);
788 i2c_del_adapter(&i2c->adap);
789 return 0;
790 }
791
792 static struct platform_driver jz4780_i2c_driver = {
793 .probe = jz4780_i2c_probe,
794 .remove = jz4780_i2c_remove,
795 .driver = {
796 .name = "jz4780-i2c",
797 .of_match_table = of_match_ptr(jz4780_i2c_of_matches),
798 },
799 };
800
801 module_platform_driver(jz4780_i2c_driver);
802
803 MODULE_LICENSE("GPL");
804 MODULE_AUTHOR("ztyan<ztyan@ingenic.cn>");
805 MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs");
806