xref: /openbmc/linux/drivers/i2c/busses/i2c-jz4780.c (revision 404e077a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ingenic JZ4780 I2C bus driver
4  *
5  * Copyright (C) 2006 - 2009 Ingenic Semiconductor Inc.
6  * Copyright (C) 2015 Imagination Technologies
7  * Copyright (C) 2019 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
8  */
9 
10 #include <linux/bitops.h>
11 #include <linux/clk.h>
12 #include <linux/completion.h>
13 #include <linux/delay.h>
14 #include <linux/errno.h>
15 #include <linux/i2c.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/platform_device.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 
27 #define JZ4780_I2C_CTRL		0x00
28 #define JZ4780_I2C_TAR		0x04
29 #define JZ4780_I2C_SAR		0x08
30 #define JZ4780_I2C_DC		0x10
31 #define JZ4780_I2C_SHCNT	0x14
32 #define JZ4780_I2C_SLCNT	0x18
33 #define JZ4780_I2C_FHCNT	0x1C
34 #define JZ4780_I2C_FLCNT	0x20
35 #define JZ4780_I2C_INTST	0x2C
36 #define JZ4780_I2C_INTM		0x30
37 #define JZ4780_I2C_RXTL		0x38
38 #define JZ4780_I2C_TXTL		0x3C
39 #define JZ4780_I2C_CINTR	0x40
40 #define JZ4780_I2C_CRXUF	0x44
41 #define JZ4780_I2C_CRXOF	0x48
42 #define JZ4780_I2C_CTXOF	0x4C
43 #define JZ4780_I2C_CRXREQ	0x50
44 #define JZ4780_I2C_CTXABRT	0x54
45 #define JZ4780_I2C_CRXDONE	0x58
46 #define JZ4780_I2C_CACT		0x5C
47 #define JZ4780_I2C_CSTP		0x60
48 #define JZ4780_I2C_CSTT		0x64
49 #define JZ4780_I2C_CGC		0x68
50 #define JZ4780_I2C_ENB		0x6C
51 #define JZ4780_I2C_STA		0x70
52 #define JZ4780_I2C_TXABRT	0x80
53 #define JZ4780_I2C_DMACR	0x88
54 #define JZ4780_I2C_DMATDLR	0x8C
55 #define JZ4780_I2C_DMARDLR	0x90
56 #define JZ4780_I2C_SDASU	0x94
57 #define JZ4780_I2C_ACKGC	0x98
58 #define JZ4780_I2C_ENSTA	0x9C
59 #define JZ4780_I2C_SDAHD	0xD0
60 #define X1000_I2C_SDAHD		0x7C
61 
62 #define JZ4780_I2C_CTRL_STPHLD		BIT(7)
63 #define JZ4780_I2C_CTRL_SLVDIS		BIT(6)
64 #define JZ4780_I2C_CTRL_REST		BIT(5)
65 #define JZ4780_I2C_CTRL_MATP		BIT(4)
66 #define JZ4780_I2C_CTRL_SATP		BIT(3)
67 #define JZ4780_I2C_CTRL_SPDF		BIT(2)
68 #define JZ4780_I2C_CTRL_SPDS		BIT(1)
69 #define JZ4780_I2C_CTRL_MD		BIT(0)
70 
71 #define JZ4780_I2C_STA_SLVACT		BIT(6)
72 #define JZ4780_I2C_STA_MSTACT		BIT(5)
73 #define JZ4780_I2C_STA_RFF		BIT(4)
74 #define JZ4780_I2C_STA_RFNE		BIT(3)
75 #define JZ4780_I2C_STA_TFE		BIT(2)
76 #define JZ4780_I2C_STA_TFNF		BIT(1)
77 #define JZ4780_I2C_STA_ACT		BIT(0)
78 
79 #define X1000_I2C_DC_STOP		BIT(9)
80 
81 #define JZ4780_I2C_INTST_IGC		BIT(11)
82 #define JZ4780_I2C_INTST_ISTT		BIT(10)
83 #define JZ4780_I2C_INTST_ISTP		BIT(9)
84 #define JZ4780_I2C_INTST_IACT		BIT(8)
85 #define JZ4780_I2C_INTST_RXDN		BIT(7)
86 #define JZ4780_I2C_INTST_TXABT		BIT(6)
87 #define JZ4780_I2C_INTST_RDREQ		BIT(5)
88 #define JZ4780_I2C_INTST_TXEMP		BIT(4)
89 #define JZ4780_I2C_INTST_TXOF		BIT(3)
90 #define JZ4780_I2C_INTST_RXFL		BIT(2)
91 #define JZ4780_I2C_INTST_RXOF		BIT(1)
92 #define JZ4780_I2C_INTST_RXUF		BIT(0)
93 
94 #define JZ4780_I2C_INTM_MIGC		BIT(11)
95 #define JZ4780_I2C_INTM_MISTT		BIT(10)
96 #define JZ4780_I2C_INTM_MISTP		BIT(9)
97 #define JZ4780_I2C_INTM_MIACT		BIT(8)
98 #define JZ4780_I2C_INTM_MRXDN		BIT(7)
99 #define JZ4780_I2C_INTM_MTXABT		BIT(6)
100 #define JZ4780_I2C_INTM_MRDREQ		BIT(5)
101 #define JZ4780_I2C_INTM_MTXEMP		BIT(4)
102 #define JZ4780_I2C_INTM_MTXOF		BIT(3)
103 #define JZ4780_I2C_INTM_MRXFL		BIT(2)
104 #define JZ4780_I2C_INTM_MRXOF		BIT(1)
105 #define JZ4780_I2C_INTM_MRXUF		BIT(0)
106 
107 #define JZ4780_I2C_DC_READ		BIT(8)
108 
109 #define JZ4780_I2C_SDAHD_HDENB		BIT(8)
110 
111 #define JZ4780_I2C_ENB_I2C		BIT(0)
112 
113 #define JZ4780_I2CSHCNT_ADJUST(n)	(((n) - 8) < 6 ? 6 : ((n) - 8))
114 #define JZ4780_I2CSLCNT_ADJUST(n)	(((n) - 1) < 8 ? 8 : ((n) - 1))
115 #define JZ4780_I2CFHCNT_ADJUST(n)	(((n) - 8) < 6 ? 6 : ((n) - 8))
116 #define JZ4780_I2CFLCNT_ADJUST(n)	(((n) - 1) < 8 ? 8 : ((n) - 1))
117 
118 #define JZ4780_I2C_FIFO_LEN	16
119 
120 #define X1000_I2C_FIFO_LEN	64
121 
122 #define JZ4780_I2C_TIMEOUT	300
123 
124 #define BUFSIZE 200
125 
126 enum ingenic_i2c_version {
127 	ID_JZ4780,
128 	ID_X1000,
129 };
130 
131 /* ingenic_i2c_config: SoC specific config data. */
132 struct ingenic_i2c_config {
133 	enum ingenic_i2c_version version;
134 
135 	int fifosize;
136 	int tx_level;
137 	int rx_level;
138 };
139 
140 struct jz4780_i2c {
141 	void __iomem		*iomem;
142 	int			 irq;
143 	struct clk		*clk;
144 	struct i2c_adapter	 adap;
145 	const struct ingenic_i2c_config *cdata;
146 
147 	/* lock to protect rbuf and wbuf between xfer_rd/wr and irq handler */
148 	spinlock_t		lock;
149 
150 	/* beginning of lock scope */
151 	unsigned char		*rbuf;
152 	int			rd_total_len;
153 	int			rd_data_xfered;
154 	int			rd_cmd_xfered;
155 
156 	unsigned char		*wbuf;
157 	int			wt_len;
158 
159 	int			is_write;
160 	int			stop_hold;
161 	int			speed;
162 
163 	int			data_buf[BUFSIZE];
164 	int			cmd_buf[BUFSIZE];
165 	int			cmd;
166 
167 	/* end of lock scope */
168 	struct completion	trans_waitq;
169 };
170 
171 static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c,
172 					      unsigned long offset)
173 {
174 	return readw(i2c->iomem + offset);
175 }
176 
177 static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c,
178 				     unsigned long offset, unsigned short val)
179 {
180 	writew(val, i2c->iomem + offset);
181 }
182 
183 static int jz4780_i2c_disable(struct jz4780_i2c *i2c)
184 {
185 	unsigned short regval;
186 	unsigned long loops = 5;
187 
188 	jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0);
189 
190 	do {
191 		regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
192 		if (!(regval & JZ4780_I2C_ENB_I2C))
193 			return 0;
194 
195 		usleep_range(5000, 15000);
196 	} while (--loops);
197 
198 	dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval);
199 	return -ETIMEDOUT;
200 }
201 
202 static int jz4780_i2c_enable(struct jz4780_i2c *i2c)
203 {
204 	unsigned short regval;
205 	unsigned long loops = 5;
206 
207 	jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1);
208 
209 	do {
210 		regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);
211 		if (regval & JZ4780_I2C_ENB_I2C)
212 			return 0;
213 
214 		usleep_range(5000, 15000);
215 	} while (--loops);
216 
217 	dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval);
218 	return -ETIMEDOUT;
219 }
220 
221 static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address)
222 {
223 	unsigned short regval;
224 	unsigned long loops = 5;
225 
226 	do {
227 		regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
228 		if ((regval & JZ4780_I2C_STA_TFE) &&
229 		    !(regval & JZ4780_I2C_STA_MSTACT))
230 			break;
231 
232 		usleep_range(5000, 15000);
233 	} while (--loops);
234 
235 	if (loops) {
236 		jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address);
237 		return 0;
238 	}
239 
240 	dev_err(&i2c->adap.dev,
241 		"set device to address 0x%02x failed, STA=0x%04x\n",
242 		address, regval);
243 
244 	return -ENXIO;
245 }
246 
247 static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c)
248 {
249 	int dev_clk_khz = clk_get_rate(i2c->clk) / 1000;
250 	int cnt_high = 0;	/* HIGH period count of the SCL clock */
251 	int cnt_low = 0;	/* LOW period count of the SCL clock */
252 	int cnt_period = 0;	/* period count of the SCL clock */
253 	int setup_time = 0;
254 	int hold_time = 0;
255 	unsigned short tmp = 0;
256 	int i2c_clk = i2c->speed;
257 
258 	if (jz4780_i2c_disable(i2c))
259 		dev_dbg(&i2c->adap.dev, "i2c not disabled\n");
260 
261 	/*
262 	 * 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk)
263 	 * standard mode, min LOW and HIGH period are 4700 ns and 4000 ns
264 	 * fast mode, min LOW and HIGH period are 1300 ns and 600 ns
265 	 */
266 	cnt_period = dev_clk_khz / i2c_clk;
267 
268 	if (i2c_clk <= 100)
269 		cnt_high = (cnt_period * 4000) / (4700 + 4000);
270 	else
271 		cnt_high = (cnt_period * 600) / (1300 + 600);
272 
273 	cnt_low = cnt_period - cnt_high;
274 
275 	/*
276 	 * NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because
277 	 * normal read are 2 messages, we cannot disable i2c controller
278 	 * between these two messages, this means that we must always set
279 	 * JZ4780_I2C_CTRL_REST when init JZ4780_I2C_CTRL
280 	 *
281 	 */
282 	if (i2c_clk <= 100) {
283 		tmp = JZ4780_I2C_CTRL_SPDS | JZ4780_I2C_CTRL_REST
284 		      | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
285 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
286 
287 		jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT,
288 				  JZ4780_I2CSHCNT_ADJUST(cnt_high));
289 		jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT,
290 				  JZ4780_I2CSLCNT_ADJUST(cnt_low));
291 	} else {
292 		tmp = JZ4780_I2C_CTRL_SPDF | JZ4780_I2C_CTRL_REST
293 		      | JZ4780_I2C_CTRL_SLVDIS | JZ4780_I2C_CTRL_MD;
294 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
295 
296 		jz4780_i2c_writew(i2c, JZ4780_I2C_FHCNT,
297 				  JZ4780_I2CFHCNT_ADJUST(cnt_high));
298 		jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT,
299 				  JZ4780_I2CFLCNT_ADJUST(cnt_low));
300 	}
301 
302 	/*
303 	 * a i2c device must internally provide a hold time at least 300ns
304 	 * tHD:DAT
305 	 *	Standard Mode: min=300ns, max=3450ns
306 	 *	Fast Mode: min=0ns, max=900ns
307 	 * tSU:DAT
308 	 *	Standard Mode: min=250ns, max=infinite
309 	 *	Fast Mode: min=100(250ns is recommended), max=infinite
310 	 *
311 	 * 1i2c_clk = 10^6 / dev_clk_khz
312 	 * on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns
313 	 * on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns
314 	 *
315 	 * The actual hold time is (SDAHD + 1) * (i2c_clk period).
316 	 *
317 	 * Length of setup time calculated using (SDASU - 1) * (ic_clk_period)
318 	 *
319 	 */
320 	if (i2c_clk <= 100) { /* standard mode */
321 		setup_time = 300;
322 		hold_time = 400;
323 	} else {
324 		setup_time = 450;
325 		hold_time = 450;
326 	}
327 
328 	hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1;
329 	setup_time = ((setup_time * dev_clk_khz) / 1000000)  + 1;
330 
331 	if (setup_time > 255)
332 		setup_time = 255;
333 
334 	if (setup_time <= 0)
335 		setup_time = 1;
336 
337 	jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time);
338 
339 	if (hold_time > 255)
340 		hold_time = 255;
341 
342 	if (hold_time >= 0) {
343 		/*i2c hold time enable */
344 		if (i2c->cdata->version >= ID_X1000) {
345 			jz4780_i2c_writew(i2c, X1000_I2C_SDAHD, hold_time);
346 		} else {
347 			hold_time |= JZ4780_I2C_SDAHD_HDENB;
348 			jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time);
349 		}
350 	} else {
351 		/* disable hold time */
352 		if (i2c->cdata->version >= ID_X1000)
353 			jz4780_i2c_writew(i2c, X1000_I2C_SDAHD, 0);
354 		else
355 			jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0);
356 	}
357 
358 	return 0;
359 }
360 
361 static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c)
362 {
363 	int ret;
364 	unsigned long flags;
365 	unsigned short tmp;
366 
367 	spin_lock_irqsave(&i2c->lock, flags);
368 
369 	/* can send stop now if need */
370 	if (i2c->cdata->version < ID_X1000) {
371 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
372 		tmp &= ~JZ4780_I2C_CTRL_STPHLD;
373 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
374 	}
375 
376 	/* disable all interrupts first */
377 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
378 
379 	/* then clear all interrupts */
380 	jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT);
381 	jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR);
382 
383 	/* then disable the controller */
384 	tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
385 	tmp &= ~JZ4780_I2C_ENB_I2C;
386 	jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
387 	udelay(10);
388 	tmp |= JZ4780_I2C_ENB_I2C;
389 	jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
390 
391 	spin_unlock_irqrestore(&i2c->lock, flags);
392 
393 	ret = jz4780_i2c_disable(i2c);
394 	if (ret)
395 		dev_err(&i2c->adap.dev,
396 			"unable to disable device during cleanup!\n");
397 
398 	if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM)
399 		     & jz4780_i2c_readw(i2c, JZ4780_I2C_INTST)))
400 		dev_err(&i2c->adap.dev,
401 			"device has interrupts after a complete cleanup!\n");
402 
403 	return ret;
404 }
405 
406 static int jz4780_i2c_prepare(struct jz4780_i2c *i2c)
407 {
408 	jz4780_i2c_set_speed(i2c);
409 	return jz4780_i2c_enable(i2c);
410 }
411 
412 static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c,
413 								 int cmd_count,
414 								 int cmd_left)
415 {
416 	int i;
417 
418 	for (i = 0; i < cmd_count - 1; i++)
419 		jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
420 
421 	if ((cmd_left == 0) && (i2c->cdata->version >= ID_X1000))
422 		jz4780_i2c_writew(i2c, JZ4780_I2C_DC,
423 				JZ4780_I2C_DC_READ | X1000_I2C_DC_STOP);
424 	else
425 		jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);
426 }
427 
428 static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c)
429 {
430 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);
431 	complete(&i2c->trans_waitq);
432 }
433 
434 static irqreturn_t jz4780_i2c_irq(int irqno, void *dev_id)
435 {
436 	unsigned short tmp;
437 	unsigned short intst;
438 	unsigned short intmsk;
439 	struct jz4780_i2c *i2c = dev_id;
440 
441 	spin_lock(&i2c->lock);
442 	intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
443 	intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST);
444 
445 	intst &= intmsk;
446 
447 	if (intst & JZ4780_I2C_INTST_TXABT) {
448 		jz4780_i2c_trans_done(i2c);
449 		goto done;
450 	}
451 
452 	if (intst & JZ4780_I2C_INTST_RXOF) {
453 		dev_dbg(&i2c->adap.dev, "received fifo overflow!\n");
454 		jz4780_i2c_trans_done(i2c);
455 		goto done;
456 	}
457 
458 	/*
459 	 * When reading, always drain RX FIFO before we send more Read
460 	 * Commands to avoid fifo overrun
461 	 */
462 	if (i2c->is_write == 0) {
463 		int rd_left;
464 
465 		while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA)
466 				  & JZ4780_I2C_STA_RFNE)) {
467 			*(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC)
468 					 & 0xff;
469 			i2c->rd_data_xfered++;
470 			if (i2c->rd_data_xfered == i2c->rd_total_len) {
471 				jz4780_i2c_trans_done(i2c);
472 				goto done;
473 			}
474 		}
475 
476 		rd_left = i2c->rd_total_len - i2c->rd_data_xfered;
477 
478 		if (rd_left <= i2c->cdata->fifosize)
479 			jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1);
480 	}
481 
482 	if (intst & JZ4780_I2C_INTST_TXEMP) {
483 		if (i2c->is_write == 0) {
484 			int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;
485 			int max_send = (i2c->cdata->fifosize - 1)
486 					 - (i2c->rd_cmd_xfered
487 					 - i2c->rd_data_xfered);
488 			int cmd_to_send = min(cmd_left, max_send);
489 
490 			if (i2c->rd_cmd_xfered != 0)
491 				cmd_to_send = min(cmd_to_send,
492 						  i2c->cdata->fifosize
493 						  - i2c->cdata->tx_level - 1);
494 
495 			if (cmd_to_send) {
496 				i2c->rd_cmd_xfered += cmd_to_send;
497 				cmd_left = i2c->rd_total_len -
498 						i2c->rd_cmd_xfered;
499 				jz4780_i2c_send_rcmd(i2c,
500 						cmd_to_send, cmd_left);
501 
502 			}
503 
504 			if (cmd_left == 0) {
505 				intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);
506 				intmsk &= ~JZ4780_I2C_INTM_MTXEMP;
507 				jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk);
508 
509 				if (i2c->cdata->version < ID_X1000) {
510 					tmp = jz4780_i2c_readw(i2c,
511 							JZ4780_I2C_CTRL);
512 					tmp &= ~JZ4780_I2C_CTRL_STPHLD;
513 					jz4780_i2c_writew(i2c,
514 							JZ4780_I2C_CTRL, tmp);
515 				}
516 			}
517 		} else {
518 			unsigned short data;
519 			unsigned short i2c_sta;
520 
521 			i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
522 
523 			while ((i2c_sta & JZ4780_I2C_STA_TFNF) &&
524 					(i2c->wt_len > 0)) {
525 				i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
526 				data = *i2c->wbuf;
527 				data &= ~JZ4780_I2C_DC_READ;
528 				if ((i2c->wt_len == 1) && (!i2c->stop_hold) &&
529 						(i2c->cdata->version >= ID_X1000))
530 					data |= X1000_I2C_DC_STOP;
531 				jz4780_i2c_writew(i2c, JZ4780_I2C_DC, data);
532 				i2c->wbuf++;
533 				i2c->wt_len--;
534 			}
535 
536 			if (i2c->wt_len == 0) {
537 				if ((!i2c->stop_hold) && (i2c->cdata->version <
538 						ID_X1000)) {
539 					tmp = jz4780_i2c_readw(i2c,
540 							JZ4780_I2C_CTRL);
541 					tmp &= ~JZ4780_I2C_CTRL_STPHLD;
542 					jz4780_i2c_writew(i2c,
543 							JZ4780_I2C_CTRL, tmp);
544 				}
545 
546 				jz4780_i2c_trans_done(i2c);
547 				goto done;
548 			}
549 		}
550 	}
551 
552 done:
553 	spin_unlock(&i2c->lock);
554 	return IRQ_HANDLED;
555 }
556 
557 static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src)
558 {
559 	dev_dbg(&i2c->adap.dev, "txabrt: 0x%08x, cmd: %d, send: %d, recv: %d\n",
560 		src, i2c->cmd, i2c->cmd_buf[i2c->cmd], i2c->data_buf[i2c->cmd]);
561 }
562 
563 static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c,
564 				       unsigned char *buf, int len, int cnt,
565 				       int idx)
566 {
567 	int ret = 0;
568 	long timeout;
569 	int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
570 	unsigned short tmp;
571 	unsigned long flags;
572 
573 	memset(buf, 0, len);
574 
575 	spin_lock_irqsave(&i2c->lock, flags);
576 
577 	i2c->stop_hold = 0;
578 	i2c->is_write = 0;
579 	i2c->rbuf = buf;
580 	i2c->rd_total_len = len;
581 	i2c->rd_data_xfered = 0;
582 	i2c->rd_cmd_xfered = 0;
583 
584 	if (len <= i2c->cdata->fifosize)
585 		jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1);
586 	else
587 		jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, i2c->cdata->rx_level);
588 
589 	jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, i2c->cdata->tx_level);
590 
591 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM,
592 			  JZ4780_I2C_INTM_MRXFL | JZ4780_I2C_INTM_MTXEMP
593 			  | JZ4780_I2C_INTM_MTXABT | JZ4780_I2C_INTM_MRXOF);
594 
595 	if (i2c->cdata->version < ID_X1000) {
596 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
597 		tmp |= JZ4780_I2C_CTRL_STPHLD;
598 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
599 	}
600 
601 	spin_unlock_irqrestore(&i2c->lock, flags);
602 
603 	timeout = wait_for_completion_timeout(&i2c->trans_waitq,
604 					      msecs_to_jiffies(wait_time));
605 
606 	if (!timeout) {
607 		dev_err(&i2c->adap.dev, "irq read timeout\n");
608 		dev_dbg(&i2c->adap.dev, "send cmd count:%d  %d\n",
609 			i2c->cmd, i2c->cmd_buf[i2c->cmd]);
610 		dev_dbg(&i2c->adap.dev, "receive data count:%d  %d\n",
611 			i2c->cmd, i2c->data_buf[i2c->cmd]);
612 		ret = -EIO;
613 	}
614 
615 	tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
616 	if (tmp) {
617 		jz4780_i2c_txabrt(i2c, tmp);
618 		ret = -EIO;
619 	}
620 
621 	return ret;
622 }
623 
624 static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c,
625 					unsigned char *buf, int len,
626 					int cnt, int idx)
627 {
628 	int ret = 0;
629 	int wait_time = JZ4780_I2C_TIMEOUT * (len + 5);
630 	long timeout;
631 	unsigned short tmp;
632 	unsigned long flags;
633 
634 	spin_lock_irqsave(&i2c->lock, flags);
635 
636 	if (idx < (cnt - 1))
637 		i2c->stop_hold = 1;
638 	else
639 		i2c->stop_hold = 0;
640 
641 	i2c->is_write = 1;
642 	i2c->wbuf = buf;
643 	i2c->wt_len = len;
644 
645 	jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, i2c->cdata->tx_level);
646 
647 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP
648 					| JZ4780_I2C_INTM_MTXABT);
649 
650 	if (i2c->cdata->version < ID_X1000) {
651 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
652 		tmp |= JZ4780_I2C_CTRL_STPHLD;
653 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
654 	}
655 
656 	spin_unlock_irqrestore(&i2c->lock, flags);
657 
658 	timeout = wait_for_completion_timeout(&i2c->trans_waitq,
659 					      msecs_to_jiffies(wait_time));
660 	if (timeout && !i2c->stop_hold) {
661 		unsigned short i2c_sta;
662 		int write_in_process;
663 
664 		timeout = JZ4780_I2C_TIMEOUT * 100;
665 		for (; timeout > 0; timeout--) {
666 			i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);
667 
668 			write_in_process = (i2c_sta & JZ4780_I2C_STA_MSTACT) ||
669 				!(i2c_sta & JZ4780_I2C_STA_TFE);
670 			if (!write_in_process)
671 				break;
672 			udelay(10);
673 		}
674 	}
675 
676 	if (!timeout) {
677 		dev_err(&i2c->adap.dev, "write wait timeout\n");
678 		ret = -EIO;
679 	}
680 
681 	tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);
682 	if (tmp) {
683 		jz4780_i2c_txabrt(i2c, tmp);
684 		ret = -EIO;
685 	}
686 
687 	return ret;
688 }
689 
690 static int jz4780_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
691 			   int count)
692 {
693 	int i = -EIO;
694 	int ret = 0;
695 	struct jz4780_i2c *i2c = adap->algo_data;
696 
697 	ret = jz4780_i2c_prepare(i2c);
698 	if (ret) {
699 		dev_err(&i2c->adap.dev, "I2C prepare failed\n");
700 		goto out;
701 	}
702 
703 	if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) {
704 		ret = jz4780_i2c_set_target(i2c, msg->addr);
705 		if (ret)
706 			goto out;
707 	}
708 	for (i = 0; i < count; i++, msg++) {
709 		if (msg->flags & I2C_M_RD)
710 			ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len,
711 						   count, i);
712 		else
713 			ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len,
714 						    count, i);
715 
716 		if (ret)
717 			goto out;
718 	}
719 
720 	ret = i;
721 
722 out:
723 	jz4780_i2c_cleanup(i2c);
724 	return ret;
725 }
726 
727 static u32 jz4780_i2c_functionality(struct i2c_adapter *adap)
728 {
729 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
730 }
731 
732 static const struct i2c_algorithm jz4780_i2c_algorithm = {
733 	.master_xfer	= jz4780_i2c_xfer,
734 	.functionality	= jz4780_i2c_functionality,
735 };
736 
737 static const struct ingenic_i2c_config jz4780_i2c_config = {
738 	.version = ID_JZ4780,
739 
740 	.fifosize = JZ4780_I2C_FIFO_LEN,
741 	.tx_level = JZ4780_I2C_FIFO_LEN / 2,
742 	.rx_level = JZ4780_I2C_FIFO_LEN / 2 - 1,
743 };
744 
745 static const struct ingenic_i2c_config x1000_i2c_config = {
746 	.version = ID_X1000,
747 
748 	.fifosize = X1000_I2C_FIFO_LEN,
749 	.tx_level = X1000_I2C_FIFO_LEN / 2,
750 	.rx_level = X1000_I2C_FIFO_LEN / 2 - 1,
751 };
752 
753 static const struct of_device_id jz4780_i2c_of_matches[] = {
754 	{ .compatible = "ingenic,jz4770-i2c", .data = &jz4780_i2c_config },
755 	{ .compatible = "ingenic,jz4780-i2c", .data = &jz4780_i2c_config },
756 	{ .compatible = "ingenic,x1000-i2c", .data = &x1000_i2c_config },
757 	{ /* sentinel */ }
758 };
759 MODULE_DEVICE_TABLE(of, jz4780_i2c_of_matches);
760 
761 static int jz4780_i2c_probe(struct platform_device *pdev)
762 {
763 	int ret = 0;
764 	unsigned int clk_freq = 0;
765 	unsigned short tmp;
766 	struct jz4780_i2c *i2c;
767 
768 	i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);
769 	if (!i2c)
770 		return -ENOMEM;
771 
772 	i2c->cdata = device_get_match_data(&pdev->dev);
773 	if (!i2c->cdata) {
774 		dev_err(&pdev->dev, "Error: No device match found\n");
775 		return -ENODEV;
776 	}
777 
778 	i2c->adap.owner		= THIS_MODULE;
779 	i2c->adap.algo		= &jz4780_i2c_algorithm;
780 	i2c->adap.algo_data	= i2c;
781 	i2c->adap.retries	= 5;
782 	i2c->adap.dev.parent	= &pdev->dev;
783 	i2c->adap.dev.of_node	= pdev->dev.of_node;
784 	sprintf(i2c->adap.name, "%s", pdev->name);
785 
786 	init_completion(&i2c->trans_waitq);
787 	spin_lock_init(&i2c->lock);
788 
789 	i2c->iomem = devm_platform_ioremap_resource(pdev, 0);
790 	if (IS_ERR(i2c->iomem))
791 		return PTR_ERR(i2c->iomem);
792 
793 	platform_set_drvdata(pdev, i2c);
794 
795 	i2c->clk = devm_clk_get(&pdev->dev, NULL);
796 	if (IS_ERR(i2c->clk))
797 		return PTR_ERR(i2c->clk);
798 
799 	ret = clk_prepare_enable(i2c->clk);
800 	if (ret)
801 		return ret;
802 
803 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
804 				   &clk_freq);
805 	if (ret) {
806 		dev_err(&pdev->dev, "clock-frequency not specified in DT\n");
807 		goto err;
808 	}
809 
810 	i2c->speed = clk_freq / 1000;
811 	if (i2c->speed == 0) {
812 		ret = -EINVAL;
813 		dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");
814 		goto err;
815 	}
816 	jz4780_i2c_set_speed(i2c);
817 
818 	dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);
819 
820 	if (i2c->cdata->version < ID_X1000) {
821 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);
822 		tmp &= ~JZ4780_I2C_CTRL_STPHLD;
823 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);
824 	}
825 
826 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0);
827 
828 	ret = platform_get_irq(pdev, 0);
829 	if (ret < 0)
830 		goto err;
831 	i2c->irq = ret;
832 	ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
833 			       dev_name(&pdev->dev), i2c);
834 	if (ret)
835 		goto err;
836 
837 	ret = i2c_add_adapter(&i2c->adap);
838 	if (ret < 0)
839 		goto err;
840 
841 	return 0;
842 
843 err:
844 	clk_disable_unprepare(i2c->clk);
845 	return ret;
846 }
847 
848 static void jz4780_i2c_remove(struct platform_device *pdev)
849 {
850 	struct jz4780_i2c *i2c = platform_get_drvdata(pdev);
851 
852 	clk_disable_unprepare(i2c->clk);
853 	i2c_del_adapter(&i2c->adap);
854 }
855 
856 static struct platform_driver jz4780_i2c_driver = {
857 	.probe		= jz4780_i2c_probe,
858 	.remove_new	= jz4780_i2c_remove,
859 	.driver		= {
860 		.name	= "jz4780-i2c",
861 		.of_match_table = jz4780_i2c_of_matches,
862 	},
863 };
864 
865 module_platform_driver(jz4780_i2c_driver);
866 
867 MODULE_LICENSE("GPL");
868 MODULE_AUTHOR("ztyan<ztyan@ingenic.cn>");
869 MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs");
870