1 // SPDX-License-Identifier: GPL-2.0
3  * Driver for the Renesas R-Car I2C unit
5  * Copyright (C) 2014-19 Wolfram Sang <wsa@sang-engineering.com>
6  * Copyright (C) 2011-2019 Renesas Electronics Corporation
8  * Copyright (C) 2012-14 Renesas Solutions Corp.
11  * This file is based on the drivers/i2c/busses/i2c-sh7760.c
12  * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com>
18 #include <linux/dma-mapping.h>
24 #include <linux/i2c-smbus.h>
54 #define MDBS	BIT(7)	/* non-fifo mode switch */
147 #define rcar_i2c_priv_to_dev(p)		((p)->adap.dev.parent)
148 #define rcar_i2c_is_recv(p)		((p)->msg->flags & I2C_M_RD)
152 	writel(val, priv->io + reg);  in rcar_i2c_write()
157 	return readl(priv->io + reg);  in rcar_i2c_read()
162 	writel(~val & 0x7f, priv->io + ICMSR);  in rcar_i2c_clear_irq()
178 		priv->recovery_icmcr |= FSCL;  in rcar_i2c_set_scl()
180 		priv->recovery_icmcr &= ~FSCL;  in rcar_i2c_set_scl()
182 	rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);  in rcar_i2c_set_scl()
190 		priv->recovery_icmcr |= FSDA;  in rcar_i2c_set_sda()
192 		priv->recovery_icmcr &= ~FSDA;  in rcar_i2c_set_sda()
194 	rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);  in rcar_i2c_set_sda()
219 	rcar_i2c_write(priv, ICCCR, priv->icccr);  in rcar_i2c_init()
221 	if (priv->devtype == I2C_RCAR_GEN3)  in rcar_i2c_init()
231 	ret = readl_poll_timeout(priv->io + ICMCR, val, !(val & FSDA), 10,  in rcar_i2c_bus_barrier()
232 				 priv->adap.timeout);  in rcar_i2c_bus_barrier()
235 		priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;  in rcar_i2c_bus_barrier()
236 		ret = i2c_recover_bus(&priv->adap);  in rcar_i2c_bus_barrier()
257 	switch (priv->devtype) {  in rcar_i2c_clock_calculate()
267 		return -EIO;  in rcar_i2c_clock_calculate()
283 	 * F[]  : integer up-valuation  in rcar_i2c_clock_calculate()
285 	rate = clk_get_rate(priv->clk);  in rcar_i2c_clock_calculate()
289 		return -EIO;  in rcar_i2c_clock_calculate()
313 	 *	scgd = (div - 20 - round + 7) / 8;  in rcar_i2c_clock_calculate()
323 	return -EIO;  in rcar_i2c_clock_calculate()
330 	priv->icccr = scgd << cdf_width | cdf;  in rcar_i2c_clock_calculate()
344 	bool rep_start = !(priv->flags & ID_REP_AFTER_RD);  in rcar_i2c_prepare_msg()
346 	priv->pos = 0;  in rcar_i2c_prepare_msg()
347 	priv->flags &= ID_P_MASK;  in rcar_i2c_prepare_msg()
349 	if (priv->msgs_left == 1)  in rcar_i2c_prepare_msg()
350 		priv->flags |= ID_LAST_MSG;  in rcar_i2c_prepare_msg()
352 	rcar_i2c_write(priv, ICMAR, i2c_8bit_addr_from_msg(priv->msg));  in rcar_i2c_prepare_msg()
353 	if (priv->flags & ID_P_NOT_ATOMIC)  in rcar_i2c_prepare_msg()
363 	priv->msg = msgs;  in rcar_i2c_first_msg()
364 	priv->msgs_left = num;  in rcar_i2c_first_msg()
371 	priv->msg++;  in rcar_i2c_next_msg()
372 	priv->msgs_left--;  in rcar_i2c_next_msg()
379 	struct dma_chan *chan = priv->dma_direction == DMA_FROM_DEVICE  in rcar_i2c_cleanup_dma()
380 		? priv->dma_rx : priv->dma_tx;  in rcar_i2c_cleanup_dma()
386 	dma_unmap_single(chan->device->dev, sg_dma_address(&priv->sg),  in rcar_i2c_cleanup_dma()
387 			 sg_dma_len(&priv->sg), priv->dma_direction);  in rcar_i2c_cleanup_dma()
389 	/* Gen3 can only do one RXDMA per transfer and we just completed it */  in rcar_i2c_cleanup_dma()
390 	if (priv->devtype == I2C_RCAR_GEN3 &&  in rcar_i2c_cleanup_dma()
391 	    priv->dma_direction == DMA_FROM_DEVICE)  in rcar_i2c_cleanup_dma()
392 		priv->flags |= ID_P_NO_RXDMA;  in rcar_i2c_cleanup_dma()
394 	priv->dma_direction = DMA_NONE;  in rcar_i2c_cleanup_dma()
404 	priv->pos += sg_dma_len(&priv->sg);  in rcar_i2c_dma_callback()
412 	struct i2c_msg *msg = priv->msg;  in rcar_i2c_dma()
413 	bool read = msg->flags & I2C_M_RD;  in rcar_i2c_dma()
415 	struct dma_chan *chan = read ? priv->dma_rx : priv->dma_tx;  in rcar_i2c_dma()
423 	if (!(priv->flags & ID_P_NOT_ATOMIC) || IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||  in rcar_i2c_dma()
424 	    !(msg->flags & I2C_M_DMA_SAFE) || (read && priv->flags & ID_P_NO_RXDMA))  in rcar_i2c_dma()
432 		buf = priv->msg->buf;  in rcar_i2c_dma()
433 		len = priv->msg->len - 2;  in rcar_i2c_dma()
438 		buf = priv->msg->buf + 1;  in rcar_i2c_dma()
439 		len = priv->msg->len - 1;  in rcar_i2c_dma()
442 	dma_addr = dma_map_single(chan->device->dev, buf, len, dir);  in rcar_i2c_dma()
443 	if (dma_mapping_error(chan->device->dev, dma_addr)) {  in rcar_i2c_dma()
448 	sg_dma_len(&priv->sg) = len;  in rcar_i2c_dma()
449 	sg_dma_address(&priv->sg) = dma_addr;  in rcar_i2c_dma()
451 	priv->dma_direction = dir;  in rcar_i2c_dma()
453 	txdesc = dmaengine_prep_slave_sg(chan, &priv->sg, 1,  in rcar_i2c_dma()
462 	txdesc->callback = rcar_i2c_dma_callback;  in rcar_i2c_dma()
463 	txdesc->callback_param = priv;  in rcar_i2c_dma()
484 	struct i2c_msg *msg = priv->msg;  in rcar_i2c_irq_send()
494 	/* Check if DMA can be enabled and take over */  in rcar_i2c_irq_send()
495 	if (priv->pos == 1 && rcar_i2c_dma(priv))  in rcar_i2c_irq_send()
498 	if (priv->pos < msg->len) {  in rcar_i2c_irq_send()
504 		 * [ICRXTX] -> [SHIFT] -> [I2C bus]  in rcar_i2c_irq_send()
506 		rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);  in rcar_i2c_irq_send()
507 		priv->pos++;  in rcar_i2c_irq_send()
514 		 * [ICRXTX] -> [SHIFT] -> [I2C bus]  in rcar_i2c_irq_send()
517 		if (priv->flags & ID_LAST_MSG)  in rcar_i2c_irq_send()
533 	struct i2c_msg *msg = priv->msg;  in rcar_i2c_irq_recv()
534 	bool recv_len_init = priv->pos == 0 && msg->flags & I2C_M_RECV_LEN;  in rcar_i2c_irq_recv()
548 	} else if (priv->pos < msg->len) {  in rcar_i2c_irq_recv()
552 		msg->buf[priv->pos] = data;  in rcar_i2c_irq_recv()
555 				priv->flags |= ID_DONE | ID_EPROTO;  in rcar_i2c_irq_recv()
558 			msg->len += msg->buf[0];  in rcar_i2c_irq_recv()
565 		priv->pos++;  in rcar_i2c_irq_recv()
572 	if (priv->pos + 1 == msg->len && !recv_len_init) {  in rcar_i2c_irq_recv()
573 		if (priv->flags & ID_LAST_MSG) {  in rcar_i2c_irq_recv()
577 			priv->flags |= ID_REP_AFTER_RD;  in rcar_i2c_irq_recv()
581 	if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG))  in rcar_i2c_irq_recv()
602 			i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value);  in rcar_i2c_slave_irq()
606 			i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value);  in rcar_i2c_slave_irq()
617 		i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);  in rcar_i2c_slave_irq()
628 		ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value);  in rcar_i2c_slave_irq()
636 		i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value);  in rcar_i2c_slave_irq()
645  * This driver has a lock-free design because there are IP cores (at least
646  * R-Car Gen2) which have an inherent race condition in their hardware design.
652  * R-Car Gen3 seems to have this fixed but earlier versions than R-Car Gen2 are
666 		priv->flags |= ID_DONE | ID_ARBLOST;  in rcar_i2c_irq()
673 		if (priv->flags & ID_P_NOT_ATOMIC)  in rcar_i2c_irq()
675 		priv->flags |= ID_NACK;  in rcar_i2c_irq()
681 		priv->msgs_left--; /* The last message also made it */  in rcar_i2c_irq()
682 		priv->flags |= ID_DONE;  in rcar_i2c_irq()
692 	if (priv->flags & ID_DONE) {  in rcar_i2c_irq()
695 		if (priv->flags & ID_P_NOT_ATOMIC)  in rcar_i2c_irq()
696 			wake_up(&priv->wait);  in rcar_i2c_irq()
708 	if (likely(!(priv->flags & ID_REP_AFTER_RD)))  in rcar_i2c_gen2_irq()
713 	if (priv->flags & ID_P_NOT_ATOMIC)  in rcar_i2c_gen2_irq()
726 	if (priv->flags & ID_P_NOT_ATOMIC)  in rcar_i2c_gen3_irq()
733 	if (likely(!(priv->flags & ID_REP_AFTER_RD) && msr))  in rcar_i2c_gen3_irq()
785 	read = msg->flags & I2C_M_RD;  in rcar_i2c_request_dma()
787 	chan = read ? priv->dma_rx : priv->dma_tx;  in rcar_i2c_request_dma()
788 	if (PTR_ERR(chan) != -EPROBE_DEFER)  in rcar_i2c_request_dma()
792 	chan = rcar_i2c_request_dma_chan(dev, dir, priv->res->start + ICRXTX);  in rcar_i2c_request_dma()
795 		priv->dma_rx = chan;  in rcar_i2c_request_dma()
797 		priv->dma_tx = chan;  in rcar_i2c_request_dma()
802 	if (!IS_ERR(priv->dma_tx)) {  in rcar_i2c_release_dma()
803 		dma_release_channel(priv->dma_tx);  in rcar_i2c_release_dma()
804 		priv->dma_tx = ERR_PTR(-EPROBE_DEFER);  in rcar_i2c_release_dma()
807 	if (!IS_ERR(priv->dma_rx)) {  in rcar_i2c_release_dma()
808 		dma_release_channel(priv->dma_rx);  in rcar_i2c_release_dma()
809 		priv->dma_rx = ERR_PTR(-EPROBE_DEFER);  in rcar_i2c_release_dma()
818 	ret = reset_control_reset(priv->rstc);  in rcar_i2c_do_reset()
823 					100, false, priv->rstc);  in rcar_i2c_do_reset()
835 	priv->flags |= ID_P_NOT_ATOMIC;  in rcar_i2c_master_xfer()
845 	if (priv->devtype == I2C_RCAR_GEN3) {  in rcar_i2c_master_xfer()
846 		priv->flags |= ID_P_NO_RXDMA;  in rcar_i2c_master_xfer()
847 		if (!IS_ERR(priv->rstc)) {  in rcar_i2c_master_xfer()
850 				priv->flags &= ~ID_P_NO_RXDMA;  in rcar_i2c_master_xfer()
861 	time_left = wait_event_timeout(priv->wait, priv->flags & ID_DONE,  in rcar_i2c_master_xfer()
862 				     num * adap->timeout);  in rcar_i2c_master_xfer()
865 	if (priv->dma_direction != DMA_NONE)  in rcar_i2c_master_xfer()
870 		ret = -ETIMEDOUT;  in rcar_i2c_master_xfer()
871 	} else if (priv->flags & ID_NACK) {  in rcar_i2c_master_xfer()
872 		ret = -ENXIO;  in rcar_i2c_master_xfer()
873 	} else if (priv->flags & ID_ARBLOST) {  in rcar_i2c_master_xfer()
874 		ret = -EAGAIN;  in rcar_i2c_master_xfer()
875 	} else if (priv->flags & ID_EPROTO) {  in rcar_i2c_master_xfer()
876 		ret = -EPROTO;  in rcar_i2c_master_xfer()
878 		ret = num - priv->msgs_left; /* The number of transfer */  in rcar_i2c_master_xfer()
883 	if (ret < 0 && ret != -ENXIO)  in rcar_i2c_master_xfer()
884 		dev_err(dev, "error %d : %x\n", ret, priv->flags);  in rcar_i2c_master_xfer()
899 	priv->flags &= ~ID_P_NOT_ATOMIC;  in rcar_i2c_master_xfer_atomic()
911 	j = jiffies + num * adap->timeout;  in rcar_i2c_master_xfer_atomic()
918 			if (priv->devtype < I2C_RCAR_GEN3)  in rcar_i2c_master_xfer_atomic()
925 	} while (!(priv->flags & ID_DONE) && time_left);  in rcar_i2c_master_xfer_atomic()
929 		ret = -ETIMEDOUT;  in rcar_i2c_master_xfer_atomic()
930 	} else if (priv->flags & ID_NACK) {  in rcar_i2c_master_xfer_atomic()
931 		ret = -ENXIO;  in rcar_i2c_master_xfer_atomic()
932 	} else if (priv->flags & ID_ARBLOST) {  in rcar_i2c_master_xfer_atomic()
933 		ret = -EAGAIN;  in rcar_i2c_master_xfer_atomic()
934 	} else if (priv->flags & ID_EPROTO) {  in rcar_i2c_master_xfer_atomic()
935 		ret = -EPROTO;  in rcar_i2c_master_xfer_atomic()
937 		ret = num - priv->msgs_left; /* The number of transfer */  in rcar_i2c_master_xfer_atomic()
942 	if (ret < 0 && ret != -ENXIO)  in rcar_i2c_master_xfer_atomic()
943 		dev_err(dev, "error %d : %x\n", ret, priv->flags);  in rcar_i2c_master_xfer_atomic()
950 	struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);  in rcar_reg_slave()
952 	if (priv->slave)  in rcar_reg_slave()
953 		return -EBUSY;  in rcar_reg_slave()
955 	if (slave->flags & I2C_CLIENT_TEN)  in rcar_reg_slave()
956 		return -EAFNOSUPPORT;  in rcar_reg_slave()
961 	priv->slave = slave;  in rcar_reg_slave()
962 	rcar_i2c_write(priv, ICSAR, slave->addr);  in rcar_reg_slave()
972 	struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);  in rcar_unreg_slave()
974 	WARN_ON(!priv->slave);  in rcar_unreg_slave()
977 	disable_irq(priv->irq);  in rcar_unreg_slave()
980 	enable_irq(priv->irq);  in rcar_unreg_slave()
984 	priv->slave = NULL;  in rcar_unreg_slave()
996 	 * This HW can't do:  in rcar_i2c_func()
1004 	if (priv->flags & ID_P_HOST_NOTIFY)  in rcar_i2c_func()
1023 	{ .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
1024 	{ .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
1025 	{ .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
1026 	{ .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 },
1027 	{ .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 },
1028 	{ .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 },
1029 	{ .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
1030 	{ .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 },
1031 	{ .compatible = "renesas,i2c-r8a7796", .data = (void *)I2C_RCAR_GEN3 },
1032 	{ .compatible = "renesas,rcar-gen1-i2c", .data = (void *)I2C_RCAR_GEN1 },
1033 	{ .compatible = "renesas,rcar-gen2-i2c", .data = (void *)I2C_RCAR_GEN2 },
1034 	{ .compatible = "renesas,rcar-gen3-i2c", .data = (void *)I2C_RCAR_GEN3 },
1035 	{ .compatible = "renesas,rcar-gen4-i2c", .data = (void *)I2C_RCAR_GEN3 },
1044 	struct device *dev = &pdev->dev;  in rcar_i2c_probe()
1054 		return -ENOMEM;  in rcar_i2c_probe()
1056 	priv->clk = devm_clk_get(dev, NULL);  in rcar_i2c_probe()
1057 	if (IS_ERR(priv->clk)) {  in rcar_i2c_probe()
1059 		return PTR_ERR(priv->clk);  in rcar_i2c_probe()
1062 	priv->io = devm_platform_get_and_ioremap_resource(pdev, 0, &priv->res);  in rcar_i2c_probe()
1063 	if (IS_ERR(priv->io))  in rcar_i2c_probe()
1064 		return PTR_ERR(priv->io);  in rcar_i2c_probe()
1066 	priv->devtype = (enum rcar_i2c_type)of_device_get_match_data(dev);  in rcar_i2c_probe()
1067 	init_waitqueue_head(&priv->wait);  in rcar_i2c_probe()
1069 	adap = &priv->adap;  in rcar_i2c_probe()
1070 	adap->nr = pdev->id;  in rcar_i2c_probe()
1071 	adap->algo = &rcar_i2c_algo;  in rcar_i2c_probe()
1072 	adap->class = I2C_CLASS_DEPRECATED;  in rcar_i2c_probe()
1073 	adap->retries = 3;  in rcar_i2c_probe()
1074 	adap->dev.parent = dev;  in rcar_i2c_probe()
1075 	adap->dev.of_node = dev->of_node;  in rcar_i2c_probe()
1076 	adap->bus_recovery_info = &rcar_i2c_bri;  in rcar_i2c_probe()
1077 	adap->quirks = &rcar_i2c_quirks;  in rcar_i2c_probe()
1079 	strscpy(adap->name, pdev->name, sizeof(adap->name));  in rcar_i2c_probe()
1082 	sg_init_table(&priv->sg, 1);  in rcar_i2c_probe()
1083 	priv->dma_direction = DMA_NONE;  in rcar_i2c_probe()
1084 	priv->dma_rx = priv->dma_tx = ERR_PTR(-EPROBE_DEFER);  in rcar_i2c_probe()
1097 	if (priv->devtype < I2C_RCAR_GEN3) {  in rcar_i2c_probe()
1102 	if (priv->devtype == I2C_RCAR_GEN3) {  in rcar_i2c_probe()
1103 		priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);  in rcar_i2c_probe()
1104 		if (!IS_ERR(priv->rstc)) {  in rcar_i2c_probe()
1105 			ret = reset_control_status(priv->rstc);  in rcar_i2c_probe()
1107 				priv->rstc = ERR_PTR(-ENOTSUPP);  in rcar_i2c_probe()
1111 	/* Stay always active when multi-master to keep arbitration working */  in rcar_i2c_probe()
1112 	if (of_property_read_bool(dev->of_node, "multi-master"))  in rcar_i2c_probe()
1113 		priv->flags |= ID_P_PM_BLOCKED;  in rcar_i2c_probe()
1117 	if (of_property_read_bool(dev->of_node, "smbus"))  in rcar_i2c_probe()
1118 		priv->flags |= ID_P_HOST_NOTIFY;  in rcar_i2c_probe()
1123 	priv->irq = ret;  in rcar_i2c_probe()
1124 	ret = devm_request_irq(dev, priv->irq, irqhandler, irqflags, dev_name(dev), priv);  in rcar_i2c_probe()
1126 		dev_err(dev, "cannot get irq %d\n", priv->irq);  in rcar_i2c_probe()
1136 	if (priv->flags & ID_P_HOST_NOTIFY) {  in rcar_i2c_probe()
1137 		priv->host_notify_client = i2c_new_slave_host_notify_device(adap);  in rcar_i2c_probe()
1138 		if (IS_ERR(priv->host_notify_client)) {  in rcar_i2c_probe()
1139 			ret = PTR_ERR(priv->host_notify_client);  in rcar_i2c_probe()
1149 	i2c_del_adapter(&priv->adap);  in rcar_i2c_probe()
1151 	if (priv->flags & ID_P_PM_BLOCKED)  in rcar_i2c_probe()
1161 	struct device *dev = &pdev->dev;  in rcar_i2c_remove()
1163 	if (priv->host_notify_client)  in rcar_i2c_remove()
1164 		i2c_free_slave_host_notify_device(priv->host_notify_client);  in rcar_i2c_remove()
1165 	i2c_del_adapter(&priv->adap);  in rcar_i2c_remove()
1167 	if (priv->flags & ID_P_PM_BLOCKED)  in rcar_i2c_remove()
1179 	i2c_mark_adapter_suspended(&priv->adap);  in rcar_i2c_suspend()
1187 	i2c_mark_adapter_resumed(&priv->adap);  in rcar_i2c_resume()
1202 		.name	= "i2c-rcar",
1213 MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");