1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Ingenic JZ4780 I2C bus driver
5  * Copyright (C) 2006 - 2009 Ingenic Semiconductor Inc.
15 #include <linux/i2c.h>
68 #define JZ4780_I2C_CTRL_SPDS		BIT(1)
76 #define JZ4780_I2C_STA_TFNF		BIT(1)
91 #define JZ4780_I2C_INTST_RXOF		BIT(1)
104 #define JZ4780_I2C_INTM_MRXOF		BIT(1)
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))
171 static inline unsigned short jz4780_i2c_readw(struct jz4780_i2c *i2c,  in jz4780_i2c_readw()  argument
174 	return readw(i2c->iomem + offset);  in jz4780_i2c_readw()
177 static inline void jz4780_i2c_writew(struct jz4780_i2c *i2c,  in jz4780_i2c_writew()  argument
180 	writew(val, i2c->iomem + offset);  in jz4780_i2c_writew()
183 static int jz4780_i2c_disable(struct jz4780_i2c *i2c)  in jz4780_i2c_disable()  argument
188 	jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 0);  in jz4780_i2c_disable()
191 		regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);  in jz4780_i2c_disable()
196 	} while (--loops);  in jz4780_i2c_disable()
198 	dev_err(&i2c->adap.dev, "disable failed: ENSTA=0x%04x\n", regval);  in jz4780_i2c_disable()
199 	return -ETIMEDOUT;  in jz4780_i2c_disable()
202 static int jz4780_i2c_enable(struct jz4780_i2c *i2c)  in jz4780_i2c_enable()  argument
207 	jz4780_i2c_writew(i2c, JZ4780_I2C_ENB, 1);  in jz4780_i2c_enable()
210 		regval = jz4780_i2c_readw(i2c, JZ4780_I2C_ENSTA);  in jz4780_i2c_enable()
215 	} while (--loops);  in jz4780_i2c_enable()
217 	dev_err(&i2c->adap.dev, "enable failed: ENSTA=0x%04x\n", regval);  in jz4780_i2c_enable()
218 	return -ETIMEDOUT;  in jz4780_i2c_enable()
221 static int jz4780_i2c_set_target(struct jz4780_i2c *i2c, unsigned char address)  in jz4780_i2c_set_target()  argument
227 		regval = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);  in jz4780_i2c_set_target()
233 	} while (--loops);  in jz4780_i2c_set_target()
236 		jz4780_i2c_writew(i2c, JZ4780_I2C_TAR, address);  in jz4780_i2c_set_target()
240 	dev_err(&i2c->adap.dev,  in jz4780_i2c_set_target()
244 	return -ENXIO;  in jz4780_i2c_set_target()
247 static int jz4780_i2c_set_speed(struct jz4780_i2c *i2c)  in jz4780_i2c_set_speed()  argument
249 	int dev_clk_khz = clk_get_rate(i2c->clk) / 1000;  in jz4780_i2c_set_speed()
256 	int i2c_clk = i2c->speed;  in jz4780_i2c_set_speed()
258 	if (jz4780_i2c_disable(i2c))  in jz4780_i2c_set_speed()
259 		dev_dbg(&i2c->adap.dev, "i2c not disabled\n");  in jz4780_i2c_set_speed()
262 	 * 1 JZ4780_I2C cycle equals to cnt_period PCLK(i2c_clk)  in jz4780_i2c_set_speed()
273 	cnt_low = cnt_period - cnt_high;  in jz4780_i2c_set_speed()
276 	 * NOTE: JZ4780_I2C_CTRL_REST can't set when i2c enabled, because  in jz4780_i2c_set_speed()
277 	 * normal read are 2 messages, we cannot disable i2c controller  in jz4780_i2c_set_speed()
285 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_set_speed()
287 		jz4780_i2c_writew(i2c, JZ4780_I2C_SHCNT,  in jz4780_i2c_set_speed()
289 		jz4780_i2c_writew(i2c, JZ4780_I2C_SLCNT,  in jz4780_i2c_set_speed()
294 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_set_speed()
296 		jz4780_i2c_writew(i2c, JZ4780_I2C_FHCNT,  in jz4780_i2c_set_speed()
298 		jz4780_i2c_writew(i2c, JZ4780_I2C_FLCNT,  in jz4780_i2c_set_speed()
303 	 * a i2c device must internally provide a hold time at least 300ns  in jz4780_i2c_set_speed()
311 	 * 1i2c_clk = 10^6 / dev_clk_khz  in jz4780_i2c_set_speed()
312 	 * on FPGA, dev_clk_khz = 12000, so 1i2c_clk = 1000/12 = 83ns  in jz4780_i2c_set_speed()
313 	 * on Pisces(1008M), dev_clk_khz=126000, so 1i2c_clk = 1000 / 126 = 8ns  in jz4780_i2c_set_speed()
315 	 * The actual hold time is (SDAHD + 1) * (i2c_clk period).  in jz4780_i2c_set_speed()
317 	 * Length of setup time calculated using (SDASU - 1) * (ic_clk_period)  in jz4780_i2c_set_speed()
328 	hold_time = ((hold_time * dev_clk_khz) / 1000000) - 1;  in jz4780_i2c_set_speed()
329 	setup_time = ((setup_time * dev_clk_khz) / 1000000)  + 1;  in jz4780_i2c_set_speed()
335 		setup_time = 1;  in jz4780_i2c_set_speed()
337 	jz4780_i2c_writew(i2c, JZ4780_I2C_SDASU, setup_time);  in jz4780_i2c_set_speed()
343 		/*i2c hold time enable */  in jz4780_i2c_set_speed()
344 		if (i2c->cdata->version >= ID_X1000) {  in jz4780_i2c_set_speed()
345 			jz4780_i2c_writew(i2c, X1000_I2C_SDAHD, hold_time);  in jz4780_i2c_set_speed()
348 			jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, hold_time);  in jz4780_i2c_set_speed()
352 		if (i2c->cdata->version >= ID_X1000)  in jz4780_i2c_set_speed()
353 			jz4780_i2c_writew(i2c, X1000_I2C_SDAHD, 0);  in jz4780_i2c_set_speed()
355 			jz4780_i2c_writew(i2c, JZ4780_I2C_SDAHD, 0);  in jz4780_i2c_set_speed()
361 static int jz4780_i2c_cleanup(struct jz4780_i2c *i2c)  in jz4780_i2c_cleanup()  argument
367 	spin_lock_irqsave(&i2c->lock, flags);  in jz4780_i2c_cleanup()
370 	if (i2c->cdata->version < ID_X1000) {  in jz4780_i2c_cleanup()
371 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);  in jz4780_i2c_cleanup()
373 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_cleanup()
377 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);  in jz4780_i2c_cleanup()
380 	jz4780_i2c_readw(i2c, JZ4780_I2C_CTXABRT);  in jz4780_i2c_cleanup()
381 	jz4780_i2c_readw(i2c, JZ4780_I2C_CINTR);  in jz4780_i2c_cleanup()
384 	tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);  in jz4780_i2c_cleanup()
386 	jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_cleanup()
389 	jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_cleanup()
391 	spin_unlock_irqrestore(&i2c->lock, flags);  in jz4780_i2c_cleanup()
393 	ret = jz4780_i2c_disable(i2c);  in jz4780_i2c_cleanup()
395 		dev_err(&i2c->adap.dev,  in jz4780_i2c_cleanup()
398 	if (unlikely(jz4780_i2c_readw(i2c, JZ4780_I2C_INTM)  in jz4780_i2c_cleanup()
399 		     & jz4780_i2c_readw(i2c, JZ4780_I2C_INTST)))  in jz4780_i2c_cleanup()
400 		dev_err(&i2c->adap.dev,  in jz4780_i2c_cleanup()
406 static int jz4780_i2c_prepare(struct jz4780_i2c *i2c)  in jz4780_i2c_prepare()  argument
408 	jz4780_i2c_set_speed(i2c);  in jz4780_i2c_prepare()
409 	return jz4780_i2c_enable(i2c);  in jz4780_i2c_prepare()
412 static void jz4780_i2c_send_rcmd(struct jz4780_i2c *i2c,  in jz4780_i2c_send_rcmd()  argument
418 	for (i = 0; i < cmd_count - 1; i++)  in jz4780_i2c_send_rcmd()
419 		jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);  in jz4780_i2c_send_rcmd()
421 	if ((cmd_left == 0) && (i2c->cdata->version >= ID_X1000))  in jz4780_i2c_send_rcmd()
422 		jz4780_i2c_writew(i2c, JZ4780_I2C_DC,  in jz4780_i2c_send_rcmd()
425 		jz4780_i2c_writew(i2c, JZ4780_I2C_DC, JZ4780_I2C_DC_READ);  in jz4780_i2c_send_rcmd()
428 static void jz4780_i2c_trans_done(struct jz4780_i2c *i2c)  in jz4780_i2c_trans_done()  argument
430 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0);  in jz4780_i2c_trans_done()
431 	complete(&i2c->trans_waitq);  in jz4780_i2c_trans_done()
439 	struct jz4780_i2c *i2c = dev_id;  in jz4780_i2c_irq()  local
441 	spin_lock(&i2c->lock);  in jz4780_i2c_irq()
442 	intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);  in jz4780_i2c_irq()
443 	intst = jz4780_i2c_readw(i2c, JZ4780_I2C_INTST);  in jz4780_i2c_irq()
448 		jz4780_i2c_trans_done(i2c);  in jz4780_i2c_irq()
453 		dev_dbg(&i2c->adap.dev, "received fifo overflow!\n");  in jz4780_i2c_irq()
454 		jz4780_i2c_trans_done(i2c);  in jz4780_i2c_irq()
462 	if (i2c->is_write == 0) {  in jz4780_i2c_irq()
465 		while ((jz4780_i2c_readw(i2c, JZ4780_I2C_STA)  in jz4780_i2c_irq()
467 			*(i2c->rbuf++) = jz4780_i2c_readw(i2c, JZ4780_I2C_DC)  in jz4780_i2c_irq()
469 			i2c->rd_data_xfered++;  in jz4780_i2c_irq()
470 			if (i2c->rd_data_xfered == i2c->rd_total_len) {  in jz4780_i2c_irq()
471 				jz4780_i2c_trans_done(i2c);  in jz4780_i2c_irq()
476 		rd_left = i2c->rd_total_len - i2c->rd_data_xfered;  in jz4780_i2c_irq()
478 		if (rd_left <= i2c->cdata->fifosize)  in jz4780_i2c_irq()
479 			jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, rd_left - 1);  in jz4780_i2c_irq()
483 		if (i2c->is_write == 0) {  in jz4780_i2c_irq()
484 			int cmd_left = i2c->rd_total_len - i2c->rd_cmd_xfered;  in jz4780_i2c_irq()
485 			int max_send = (i2c->cdata->fifosize - 1)  in jz4780_i2c_irq()
486 					 - (i2c->rd_cmd_xfered  in jz4780_i2c_irq()
487 					 - i2c->rd_data_xfered);  in jz4780_i2c_irq()
490 			if (i2c->rd_cmd_xfered != 0)  in jz4780_i2c_irq()
492 						  i2c->cdata->fifosize  in jz4780_i2c_irq()
493 						  - i2c->cdata->tx_level - 1);  in jz4780_i2c_irq()
496 				i2c->rd_cmd_xfered += cmd_to_send;  in jz4780_i2c_irq()
497 				cmd_left = i2c->rd_total_len -  in jz4780_i2c_irq()
498 						i2c->rd_cmd_xfered;  in jz4780_i2c_irq()
499 				jz4780_i2c_send_rcmd(i2c,  in jz4780_i2c_irq()
505 				intmsk = jz4780_i2c_readw(i2c, JZ4780_I2C_INTM);  in jz4780_i2c_irq()
507 				jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, intmsk);  in jz4780_i2c_irq()
509 				if (i2c->cdata->version < ID_X1000) {  in jz4780_i2c_irq()
510 					tmp = jz4780_i2c_readw(i2c,  in jz4780_i2c_irq()
513 					jz4780_i2c_writew(i2c,  in jz4780_i2c_irq()
521 			i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);  in jz4780_i2c_irq()
524 					(i2c->wt_len > 0)) {  in jz4780_i2c_irq()
525 				i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);  in jz4780_i2c_irq()
526 				data = *i2c->wbuf;  in jz4780_i2c_irq()
528 				if ((i2c->wt_len == 1) && (!i2c->stop_hold) &&  in jz4780_i2c_irq()
529 						(i2c->cdata->version >= ID_X1000))  in jz4780_i2c_irq()
531 				jz4780_i2c_writew(i2c, JZ4780_I2C_DC, data);  in jz4780_i2c_irq()
532 				i2c->wbuf++;  in jz4780_i2c_irq()
533 				i2c->wt_len--;  in jz4780_i2c_irq()
536 			if (i2c->wt_len == 0) {  in jz4780_i2c_irq()
537 				if ((!i2c->stop_hold) && (i2c->cdata->version <  in jz4780_i2c_irq()
539 					tmp = jz4780_i2c_readw(i2c,  in jz4780_i2c_irq()
542 					jz4780_i2c_writew(i2c,  in jz4780_i2c_irq()
546 				jz4780_i2c_trans_done(i2c);  in jz4780_i2c_irq()
553 	spin_unlock(&i2c->lock);  in jz4780_i2c_irq()
557 static void jz4780_i2c_txabrt(struct jz4780_i2c *i2c, int src)  in jz4780_i2c_txabrt()  argument
559 	dev_dbg(&i2c->adap.dev, "txabrt: 0x%08x, cmd: %d, send: %d, recv: %d\n",  in jz4780_i2c_txabrt()
560 		src, i2c->cmd, i2c->cmd_buf[i2c->cmd], i2c->data_buf[i2c->cmd]);  in jz4780_i2c_txabrt()
563 static inline int jz4780_i2c_xfer_read(struct jz4780_i2c *i2c,  in jz4780_i2c_xfer_read()  argument
575 	spin_lock_irqsave(&i2c->lock, flags);  in jz4780_i2c_xfer_read()
577 	i2c->stop_hold = 0;  in jz4780_i2c_xfer_read()
578 	i2c->is_write = 0;  in jz4780_i2c_xfer_read()
579 	i2c->rbuf = buf;  in jz4780_i2c_xfer_read()
580 	i2c->rd_total_len = len;  in jz4780_i2c_xfer_read()
581 	i2c->rd_data_xfered = 0;  in jz4780_i2c_xfer_read()
582 	i2c->rd_cmd_xfered = 0;  in jz4780_i2c_xfer_read()
584 	if (len <= i2c->cdata->fifosize)  in jz4780_i2c_xfer_read()
585 		jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, len - 1);  in jz4780_i2c_xfer_read()
587 		jz4780_i2c_writew(i2c, JZ4780_I2C_RXTL, i2c->cdata->rx_level);  in jz4780_i2c_xfer_read()
589 	jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, i2c->cdata->tx_level);  in jz4780_i2c_xfer_read()
591 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM,  in jz4780_i2c_xfer_read()
595 	if (i2c->cdata->version < ID_X1000) {  in jz4780_i2c_xfer_read()
596 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);  in jz4780_i2c_xfer_read()
598 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_xfer_read()
601 	spin_unlock_irqrestore(&i2c->lock, flags);  in jz4780_i2c_xfer_read()
603 	time_left = wait_for_completion_timeout(&i2c->trans_waitq,  in jz4780_i2c_xfer_read()
607 		dev_err(&i2c->adap.dev, "irq read timeout\n");  in jz4780_i2c_xfer_read()
608 		dev_dbg(&i2c->adap.dev, "send cmd count:%d  %d\n",  in jz4780_i2c_xfer_read()
609 			i2c->cmd, i2c->cmd_buf[i2c->cmd]);  in jz4780_i2c_xfer_read()
610 		dev_dbg(&i2c->adap.dev, "receive data count:%d  %d\n",  in jz4780_i2c_xfer_read()
611 			i2c->cmd, i2c->data_buf[i2c->cmd]);  in jz4780_i2c_xfer_read()
612 		ret = -EIO;  in jz4780_i2c_xfer_read()
615 	tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);  in jz4780_i2c_xfer_read()
617 		jz4780_i2c_txabrt(i2c, tmp);  in jz4780_i2c_xfer_read()
618 		ret = -EIO;  in jz4780_i2c_xfer_read()
624 static inline int jz4780_i2c_xfer_write(struct jz4780_i2c *i2c,  in jz4780_i2c_xfer_write()  argument
634 	spin_lock_irqsave(&i2c->lock, flags);  in jz4780_i2c_xfer_write()
636 	if (idx < (cnt - 1))  in jz4780_i2c_xfer_write()
637 		i2c->stop_hold = 1;  in jz4780_i2c_xfer_write()
639 		i2c->stop_hold = 0;  in jz4780_i2c_xfer_write()
641 	i2c->is_write = 1;  in jz4780_i2c_xfer_write()
642 	i2c->wbuf = buf;  in jz4780_i2c_xfer_write()
643 	i2c->wt_len = len;  in jz4780_i2c_xfer_write()
645 	jz4780_i2c_writew(i2c, JZ4780_I2C_TXTL, i2c->cdata->tx_level);  in jz4780_i2c_xfer_write()
647 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, JZ4780_I2C_INTM_MTXEMP  in jz4780_i2c_xfer_write()
650 	if (i2c->cdata->version < ID_X1000) {  in jz4780_i2c_xfer_write()
651 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);  in jz4780_i2c_xfer_write()
653 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_xfer_write()
656 	spin_unlock_irqrestore(&i2c->lock, flags);  in jz4780_i2c_xfer_write()
658 	time_left = wait_for_completion_timeout(&i2c->trans_waitq,  in jz4780_i2c_xfer_write()
660 	if (time_left && !i2c->stop_hold) {  in jz4780_i2c_xfer_write()
665 		for (; time_left > 0; time_left--) {  in jz4780_i2c_xfer_write()
666 			i2c_sta = jz4780_i2c_readw(i2c, JZ4780_I2C_STA);  in jz4780_i2c_xfer_write()
677 		dev_err(&i2c->adap.dev, "write wait timeout\n");  in jz4780_i2c_xfer_write()
678 		ret = -EIO;  in jz4780_i2c_xfer_write()
681 	tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_TXABRT);  in jz4780_i2c_xfer_write()
683 		jz4780_i2c_txabrt(i2c, tmp);  in jz4780_i2c_xfer_write()
684 		ret = -EIO;  in jz4780_i2c_xfer_write()
693 	int i = -EIO;  in jz4780_i2c_xfer()
695 	struct jz4780_i2c *i2c = adap->algo_data;  in jz4780_i2c_xfer()  local
697 	ret = jz4780_i2c_prepare(i2c);  in jz4780_i2c_xfer()
699 		dev_err(&i2c->adap.dev, "I2C prepare failed\n");  in jz4780_i2c_xfer()
703 	if (msg->addr != jz4780_i2c_readw(i2c, JZ4780_I2C_TAR)) {  in jz4780_i2c_xfer()
704 		ret = jz4780_i2c_set_target(i2c, msg->addr);  in jz4780_i2c_xfer()
709 		if (msg->flags & I2C_M_RD)  in jz4780_i2c_xfer()
710 			ret = jz4780_i2c_xfer_read(i2c, msg->buf, msg->len,  in jz4780_i2c_xfer()
713 			ret = jz4780_i2c_xfer_write(i2c, msg->buf, msg->len,  in jz4780_i2c_xfer()
723 	jz4780_i2c_cleanup(i2c);  in jz4780_i2c_xfer()
742 	.rx_level = JZ4780_I2C_FIFO_LEN / 2 - 1,
750 	.rx_level = X1000_I2C_FIFO_LEN / 2 - 1,
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 },
766 	struct jz4780_i2c *i2c;  in jz4780_i2c_probe()  local
768 	i2c = devm_kzalloc(&pdev->dev, sizeof(struct jz4780_i2c), GFP_KERNEL);  in jz4780_i2c_probe()
769 	if (!i2c)  in jz4780_i2c_probe()
770 		return -ENOMEM;  in jz4780_i2c_probe()
772 	i2c->cdata = device_get_match_data(&pdev->dev);  in jz4780_i2c_probe()
773 	if (!i2c->cdata) {  in jz4780_i2c_probe()
774 		dev_err(&pdev->dev, "Error: No device match found\n");  in jz4780_i2c_probe()
775 		return -ENODEV;  in jz4780_i2c_probe()
778 	i2c->adap.owner		= THIS_MODULE;  in jz4780_i2c_probe()
779 	i2c->adap.algo		= &jz4780_i2c_algorithm;  in jz4780_i2c_probe()
780 	i2c->adap.algo_data	= i2c;  in jz4780_i2c_probe()
781 	i2c->adap.retries	= 5;  in jz4780_i2c_probe()
782 	i2c->adap.dev.parent	= &pdev->dev;  in jz4780_i2c_probe()
783 	i2c->adap.dev.of_node	= pdev->dev.of_node;  in jz4780_i2c_probe()
784 	sprintf(i2c->adap.name, "%s", pdev->name);  in jz4780_i2c_probe()
786 	init_completion(&i2c->trans_waitq);  in jz4780_i2c_probe()
787 	spin_lock_init(&i2c->lock);  in jz4780_i2c_probe()
789 	i2c->iomem = devm_platform_ioremap_resource(pdev, 0);  in jz4780_i2c_probe()
790 	if (IS_ERR(i2c->iomem))  in jz4780_i2c_probe()
791 		return PTR_ERR(i2c->iomem);  in jz4780_i2c_probe()
793 	platform_set_drvdata(pdev, i2c);  in jz4780_i2c_probe()
795 	i2c->clk = devm_clk_get_enabled(&pdev->dev, NULL);  in jz4780_i2c_probe()
796 	if (IS_ERR(i2c->clk))  in jz4780_i2c_probe()
797 		return PTR_ERR(i2c->clk);  in jz4780_i2c_probe()
799 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",  in jz4780_i2c_probe()
802 		dev_err(&pdev->dev, "clock-frequency not specified in DT\n");  in jz4780_i2c_probe()
806 	i2c->speed = clk_freq / 1000;  in jz4780_i2c_probe()
807 	if (i2c->speed == 0) {  in jz4780_i2c_probe()
808 		ret = -EINVAL;  in jz4780_i2c_probe()
809 		dev_err(&pdev->dev, "clock-frequency minimum is 1000\n");  in jz4780_i2c_probe()
812 	jz4780_i2c_set_speed(i2c);  in jz4780_i2c_probe()
814 	dev_info(&pdev->dev, "Bus frequency is %d KHz\n", i2c->speed);  in jz4780_i2c_probe()
816 	if (i2c->cdata->version < ID_X1000) {  in jz4780_i2c_probe()
817 		tmp = jz4780_i2c_readw(i2c, JZ4780_I2C_CTRL);  in jz4780_i2c_probe()
819 		jz4780_i2c_writew(i2c, JZ4780_I2C_CTRL, tmp);  in jz4780_i2c_probe()
822 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0);  in jz4780_i2c_probe()
827 	i2c->irq = ret;  in jz4780_i2c_probe()
829 	ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,  in jz4780_i2c_probe()
830 			       dev_name(&pdev->dev), i2c);  in jz4780_i2c_probe()
834 	ret = i2c_add_adapter(&i2c->adap);  in jz4780_i2c_probe()
843 	struct jz4780_i2c *i2c = platform_get_drvdata(pdev);  in jz4780_i2c_remove()  local
845 	i2c_del_adapter(&i2c->adap);  in jz4780_i2c_remove()
852 		.name	= "jz4780-i2c",
861 MODULE_DESCRIPTION("i2c driver for JZ4780 SoCs");