1 // SPDX-License-Identifier: GPL-2.0-or-later
5  * Copyright (C) 2009 - 2014 Xilinx, Inc.
9 #include <linux/delay.h>
112 /* timeout for pm runtime autosuspend */
113 #define CNDS_I2C_PM_TIMEOUT		1000	/* ms */
117 #define CDNS_I2C_DATA_INTR_DEPTH	(CDNS_I2C_FIFO_DEPTH - 2)
120 #define CDNS_I2C_TRANSFER_SIZE	(CDNS_I2C_MAX_TRANSFER_SIZE - 3)
122 #define DRIVER_NAME		"cdns-i2c"
131 #define cdns_i2c_readreg(offset)       readl_relaxed(id->membase + offset)
132 #define cdns_i2c_writereg(val, offset) writel_relaxed(val, id->membase + offset)
136  * enum cdns_i2c_mode - I2C Controller current operating mode
147  * enum cdns_i2c_slave_mode - Slave state when I2C is operating in slave mode
161  * struct cdns_i2c - I2C device private data structure
221  * cdns_i2c_clear_bus_hold - Clear bus hold bit
236 		(id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1));  in cdns_is_holdquirk()
249 	id->dev_mode = mode;  in cdns_i2c_set_mode()
250 	id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;  in cdns_i2c_set_mode()
255 		cdns_i2c_writereg(id->ctrl_reg_diva_divb |  in cdns_i2c_set_mode()
259 		 * This delay is needed to give the IP some time to switch to  in cdns_i2c_set_mode()
261 		 * will not detect any slave and without this delay, the IP will  in cdns_i2c_set_mode()
268 		cdns_i2c_writereg(id->ctrl_reg_diva_divb &  in cdns_i2c_set_mode()
273 		cdns_i2c_writereg(id->slave->addr & CDNS_I2C_ADDR_MASK,  in cdns_i2c_set_mode()
289 	if (id->slave_state == CDNS_I2C_SLAVE_STATE_IDLE) {  in cdns_i2c_slave_rcv_data()
290 		id->slave_state = CDNS_I2C_SLAVE_STATE_RECV;  in cdns_i2c_slave_rcv_data()
291 		i2c_slave_event(id->slave, I2C_SLAVE_WRITE_REQUESTED, NULL);  in cdns_i2c_slave_rcv_data()
298 	while (bytes--) {  in cdns_i2c_slave_rcv_data()
300 		i2c_slave_event(id->slave, I2C_SLAVE_WRITE_RECEIVED, &data);  in cdns_i2c_slave_rcv_data()
309 	if (id->slave_state == CDNS_I2C_SLAVE_STATE_IDLE) {  in cdns_i2c_slave_send_data()
310 		id->slave_state = CDNS_I2C_SLAVE_STATE_SEND;  in cdns_i2c_slave_send_data()
311 		i2c_slave_event(id->slave, I2C_SLAVE_READ_REQUESTED, &data);  in cdns_i2c_slave_send_data()
313 		i2c_slave_event(id->slave, I2C_SLAVE_READ_PROCESSED, &data);  in cdns_i2c_slave_send_data()
321  * cdns_i2c_slave_isr - Interrupt handler for the I2C device in slave role
351 			id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;  in cdns_i2c_slave_isr()
352 			i2c_slave_event(id->slave, I2C_SLAVE_STOP, NULL);  in cdns_i2c_slave_isr()
361 			id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;  in cdns_i2c_slave_isr()
362 			i2c_slave_event(id->slave, I2C_SLAVE_STOP, NULL);  in cdns_i2c_slave_isr()
369 		id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;  in cdns_i2c_slave_isr()
370 		i2c_slave_event(id->slave, I2C_SLAVE_STOP, NULL);  in cdns_i2c_slave_isr()
379  * cdns_i2c_master_isr - Interrupt handler for the I2C device in master role
399 	id->err_status = 0;  in cdns_i2c_master_isr()
411 	updatetx = id->recv_count > id->curr_recv_count;  in cdns_i2c_master_isr()
414 	if (id->p_recv_buf &&  in cdns_i2c_master_isr()
420 			if (id->recv_count > 0) {  in cdns_i2c_master_isr()
421 				*(id->p_recv_buf)++ =  in cdns_i2c_master_isr()
423 				id->recv_count--;  in cdns_i2c_master_isr()
424 				id->curr_recv_count--;  in cdns_i2c_master_isr()
431 				if (id->recv_count <= CDNS_I2C_FIFO_DEPTH &&  in cdns_i2c_master_isr()
432 				    !id->bus_hold_flag)  in cdns_i2c_master_isr()
436 				dev_err(id->adap.dev.parent,  in cdns_i2c_master_isr()
438 				id->err_status |= CDNS_I2C_IXR_TO;  in cdns_i2c_master_isr()
450 		 * maintain transfer size non-zero while performing a large  in cdns_i2c_master_isr()
456 			       (id->curr_recv_count - CDNS_I2C_FIFO_DEPTH))  in cdns_i2c_master_isr()
463 			if (((int)(id->recv_count) - CDNS_I2C_FIFO_DEPTH) >  in cdns_i2c_master_isr()
467 				id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE +  in cdns_i2c_master_isr()
470 				cdns_i2c_writereg(id->recv_count -  in cdns_i2c_master_isr()
473 				id->curr_recv_count = id->recv_count;  in cdns_i2c_master_isr()
478 		if ((isr_status & CDNS_I2C_IXR_COMP) && !id->recv_count) {  in cdns_i2c_master_isr()
479 			if (!id->bus_hold_flag)  in cdns_i2c_master_isr()
488 	if ((isr_status & CDNS_I2C_IXR_COMP) && !id->p_recv_buf) {  in cdns_i2c_master_isr()
493 		if (id->send_count) {  in cdns_i2c_master_isr()
494 			avail_bytes = CDNS_I2C_FIFO_DEPTH -  in cdns_i2c_master_isr()
496 			if (id->send_count > avail_bytes)  in cdns_i2c_master_isr()
499 				bytes_to_send = id->send_count;  in cdns_i2c_master_isr()
501 			while (bytes_to_send--) {  in cdns_i2c_master_isr()
503 					(*(id->p_send_buf)++),  in cdns_i2c_master_isr()
505 				id->send_count--;  in cdns_i2c_master_isr()
515 		if (!id->send_count && !id->bus_hold_flag)  in cdns_i2c_master_isr()
522 	id->err_status |= isr_status & CDNS_I2C_IXR_ERR_INTR_MASK;  in cdns_i2c_master_isr()
523 	if (id->err_status)  in cdns_i2c_master_isr()
527 		complete(&id->xfer_done);  in cdns_i2c_master_isr()
533  * cdns_i2c_isr - Interrupt handler for the I2C device
547 	if (id->dev_mode == CDNS_I2C_MODE_SLAVE)  in cdns_i2c_isr()
554  * cdns_i2c_mrecv - Prepare and start a master receive operation
562 	id->p_recv_buf = id->p_msg->buf;  in cdns_i2c_mrecv()
563 	id->recv_count = id->p_msg->len;  in cdns_i2c_mrecv()
571 	 * byte, plus one checksum byte if PEC is enabled. p_msg->len will be 2 if  in cdns_i2c_mrecv()
574 	if (id->p_msg->flags & I2C_M_RECV_LEN)  in cdns_i2c_mrecv()
575 		id->recv_count = I2C_SMBUS_BLOCK_MAX + id->p_msg->len;  in cdns_i2c_mrecv()
577 	id->curr_recv_count = id->recv_count;  in cdns_i2c_mrecv()
583 	if (id->recv_count > CDNS_I2C_FIFO_DEPTH)  in cdns_i2c_mrecv()
598 	if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) {  in cdns_i2c_mrecv()
601 		id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE;  in cdns_i2c_mrecv()
603 		cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_OFFSET);  in cdns_i2c_mrecv()
606 	/* Set the slave address in address register - triggers operation */  in cdns_i2c_mrecv()
607 	cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,  in cdns_i2c_mrecv()
610 	if (!id->bus_hold_flag &&  in cdns_i2c_mrecv()
611 		((id->p_msg->flags & I2C_M_RECV_LEN) != I2C_M_RECV_LEN) &&  in cdns_i2c_mrecv()
612 		(id->recv_count <= CDNS_I2C_FIFO_DEPTH))  in cdns_i2c_mrecv()
618  * cdns_i2c_msend - Prepare and start a master send operation
628 	id->p_recv_buf = NULL;  in cdns_i2c_msend()
629 	id->p_send_buf = id->p_msg->buf;  in cdns_i2c_msend()
630 	id->send_count = id->p_msg->len;  in cdns_i2c_msend()
641 	if (id->send_count > CDNS_I2C_FIFO_DEPTH)  in cdns_i2c_msend()
654 	avail_bytes = CDNS_I2C_FIFO_DEPTH -  in cdns_i2c_msend()
657 	if (id->send_count > avail_bytes)  in cdns_i2c_msend()
660 		bytes_to_send = id->send_count;  in cdns_i2c_msend()
662 	while (bytes_to_send--) {  in cdns_i2c_msend()
663 		cdns_i2c_writereg((*(id->p_send_buf)++), CDNS_I2C_DATA_OFFSET);  in cdns_i2c_msend()
664 		id->send_count--;  in cdns_i2c_msend()
671 	if (!id->bus_hold_flag && !id->send_count)  in cdns_i2c_msend()
673 	/* Set the slave address in address register - triggers operation. */  in cdns_i2c_msend()
674 	cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,  in cdns_i2c_msend()
681  * cdns_i2c_master_reset - Reset the interface
689 	struct cdns_i2c *id = adap->algo_data;  in cdns_i2c_master_reset()
715 	id->p_msg = msg;  in cdns_i2c_process_msg()
716 	id->err_status = 0;  in cdns_i2c_process_msg()
717 	reinit_completion(&id->xfer_done);  in cdns_i2c_process_msg()
721 	if (msg->flags & I2C_M_TEN) {  in cdns_i2c_process_msg()
732 	if (msg->flags & I2C_M_RD)  in cdns_i2c_process_msg()
738 	msg_timeout = msecs_to_jiffies((1000 * msg->len * BITS_PER_BYTE) / id->i2c_clk);  in cdns_i2c_process_msg()
742 	if (msg_timeout < adap->timeout)  in cdns_i2c_process_msg()
743 		msg_timeout = adap->timeout;  in cdns_i2c_process_msg()
746 	time_left = wait_for_completion_timeout(&id->xfer_done, msg_timeout);  in cdns_i2c_process_msg()
749 		dev_err(id->adap.dev.parent,  in cdns_i2c_process_msg()
751 		return -ETIMEDOUT;  in cdns_i2c_process_msg()
758 	if (id->err_status & CDNS_I2C_IXR_ARB_LOST)  in cdns_i2c_process_msg()
759 		return -EAGAIN;  in cdns_i2c_process_msg()
761 	if (msg->flags & I2C_M_RECV_LEN)  in cdns_i2c_process_msg()
762 		msg->len += min_t(unsigned int, msg->buf[0], I2C_SMBUS_BLOCK_MAX);  in cdns_i2c_process_msg()
768  * cdns_i2c_master_xfer - The main i2c transfer function
782 	struct cdns_i2c *id = adap->algo_data;  in cdns_i2c_master_xfer()
788 	ret = pm_runtime_resume_and_get(id->dev);  in cdns_i2c_master_xfer()
794 	if (id->dev_mode == CDNS_I2C_MODE_SLAVE) {  in cdns_i2c_master_xfer()
795 		if (id->slave_state != CDNS_I2C_SLAVE_STATE_IDLE)  in cdns_i2c_master_xfer()
796 			return -EAGAIN;  in cdns_i2c_master_xfer()
808 		ret = -EAGAIN;  in cdns_i2c_master_xfer()
812 	hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);  in cdns_i2c_master_xfer()
825 		for (count = 0; (count < num - 1 && hold_quirk); count++) {  in cdns_i2c_master_xfer()
827 				dev_warn(adap->dev.parent,  in cdns_i2c_master_xfer()
829 				ret = -EOPNOTSUPP;  in cdns_i2c_master_xfer()
833 		id->bus_hold_flag = 1;  in cdns_i2c_master_xfer()
838 		id->bus_hold_flag = 0;  in cdns_i2c_master_xfer()
843 		if (count == (num - 1))  in cdns_i2c_master_xfer()
844 			id->bus_hold_flag = 0;  in cdns_i2c_master_xfer()
851 		if (id->err_status) {  in cdns_i2c_master_xfer()
854 			if (id->err_status & CDNS_I2C_IXR_NACK) {  in cdns_i2c_master_xfer()
855 				ret = -ENXIO;  in cdns_i2c_master_xfer()
858 			ret = -EIO;  in cdns_i2c_master_xfer()
873 	pm_runtime_mark_last_busy(id->dev);  in cdns_i2c_master_xfer()
874 	pm_runtime_put_autosuspend(id->dev);  in cdns_i2c_master_xfer()
879  * cdns_i2c_func - Returns the supported features of the I2C driver
901 	struct cdns_i2c *id = container_of(slave->adapter, struct cdns_i2c,  in cdns_reg_slave()
904 	if (id->slave)  in cdns_reg_slave()
905 		return -EBUSY;  in cdns_reg_slave()
907 	if (slave->flags & I2C_CLIENT_TEN)  in cdns_reg_slave()
908 		return -EAFNOSUPPORT;  in cdns_reg_slave()
910 	ret = pm_runtime_resume_and_get(id->dev);  in cdns_reg_slave()
915 	id->slave = slave;  in cdns_reg_slave()
925 	struct cdns_i2c *id = container_of(slave->adapter, struct cdns_i2c,  in cdns_unreg_slave()
928 	pm_runtime_put(id->dev);  in cdns_unreg_slave()
931 	id->slave = NULL;  in cdns_unreg_slave()
950  * cdns_i2c_calc_divs - Calculate clock dividers
976 		return -EINVAL;  in cdns_i2c_calc_divs()
978 	last_error = -1;  in cdns_i2c_calc_divs()
984 		div_b--;  in cdns_i2c_calc_divs()
991 		current_error = ((actual_fscl > fscl) ? (actual_fscl - fscl) :  in cdns_i2c_calc_divs()
992 							(fscl - actual_fscl));  in cdns_i2c_calc_divs()
1010  * cdns_i2c_setclk - This function sets the serial clock rate for the I2C device
1030 	unsigned long fscl = id->i2c_clk;  in cdns_i2c_setclk()
1042 	id->ctrl_reg_diva_divb = ctrl_reg & (CDNS_I2C_CR_DIVA_MASK |  in cdns_i2c_setclk()
1049  * cdns_i2c_clk_notifier_cb - Clock rate change callback
1057  * New dividers are written to the HW in the pre- or post change notification
1070 	if (pm_runtime_suspended(id->dev))  in cdns_i2c_clk_notifier_cb()
1076 		unsigned long input_clk = ndata->new_rate;  in cdns_i2c_clk_notifier_cb()
1077 		unsigned long fscl = id->i2c_clk;  in cdns_i2c_clk_notifier_cb()
1083 			dev_warn(id->adap.dev.parent,  in cdns_i2c_clk_notifier_cb()
1089 		if (ndata->new_rate > ndata->old_rate)  in cdns_i2c_clk_notifier_cb()
1090 			cdns_i2c_setclk(ndata->new_rate, id);  in cdns_i2c_clk_notifier_cb()
1095 		id->input_clk = ndata->new_rate;  in cdns_i2c_clk_notifier_cb()
1097 		if (ndata->new_rate < ndata->old_rate)  in cdns_i2c_clk_notifier_cb()
1098 			cdns_i2c_setclk(ndata->new_rate, id);  in cdns_i2c_clk_notifier_cb()
1102 		if (ndata->new_rate > ndata->old_rate)  in cdns_i2c_clk_notifier_cb()
1103 			cdns_i2c_setclk(ndata->old_rate, id);  in cdns_i2c_clk_notifier_cb()
1111  * cdns_i2c_runtime_suspend -  Runtime suspend method for the driver
1122 	clk_disable(xi2c->clk);  in cdns_i2c_runtime_suspend()
1128  * cdns_i2c_runtime_resume - Runtime resume
1140 	ret = clk_enable(xi2c->clk);  in cdns_i2c_runtime_resume()
1159 	{ .compatible = "cdns,i2c-r1p10", .data = &r1p10_i2c_def },
1160 	{ .compatible = "cdns,i2c-r1p14",},
1166  * cdns_i2c_probe - Platform registration call
1182 	id = devm_kzalloc(&pdev->dev, sizeof(*id), GFP_KERNEL);  in cdns_i2c_probe()
1184 		return -ENOMEM;  in cdns_i2c_probe()
1186 	id->dev = &pdev->dev;  in cdns_i2c_probe()
1189 	match = of_match_node(cdns_i2c_of_match, pdev->dev.of_node);  in cdns_i2c_probe()
1190 	if (match && match->data) {  in cdns_i2c_probe()
1191 		const struct cdns_platform_data *data = match->data;  in cdns_i2c_probe()
1192 		id->quirks = data->quirks;  in cdns_i2c_probe()
1195 	id->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &r_mem);  in cdns_i2c_probe()
1196 	if (IS_ERR(id->membase))  in cdns_i2c_probe()
1197 		return PTR_ERR(id->membase);  in cdns_i2c_probe()
1202 	id->irq = ret;  in cdns_i2c_probe()
1204 	id->adap.owner = THIS_MODULE;  in cdns_i2c_probe()
1205 	id->adap.dev.of_node = pdev->dev.of_node;  in cdns_i2c_probe()
1206 	id->adap.algo = &cdns_i2c_algo;  in cdns_i2c_probe()
1207 	id->adap.timeout = CDNS_I2C_TIMEOUT;  in cdns_i2c_probe()
1208 	id->adap.retries = 3;		/* Default retry value. */  in cdns_i2c_probe()
1209 	id->adap.algo_data = id;  in cdns_i2c_probe()
1210 	id->adap.dev.parent = &pdev->dev;  in cdns_i2c_probe()
1211 	init_completion(&id->xfer_done);  in cdns_i2c_probe()
1212 	snprintf(id->adap.name, sizeof(id->adap.name),  in cdns_i2c_probe()
1213 		 "Cadence I2C at %08lx", (unsigned long)r_mem->start);  in cdns_i2c_probe()
1215 	id->clk = devm_clk_get(&pdev->dev, NULL);  in cdns_i2c_probe()
1216 	if (IS_ERR(id->clk)) {  in cdns_i2c_probe()
1217 		if (PTR_ERR(id->clk) != -EPROBE_DEFER)  in cdns_i2c_probe()
1218 			dev_err(&pdev->dev, "input clock not found.\n");  in cdns_i2c_probe()
1219 		return PTR_ERR(id->clk);  in cdns_i2c_probe()
1221 	ret = clk_prepare_enable(id->clk);  in cdns_i2c_probe()
1223 		dev_err(&pdev->dev, "Unable to enable clock.\n");  in cdns_i2c_probe()
1225 	pm_runtime_set_autosuspend_delay(id->dev, CNDS_I2C_PM_TIMEOUT);  in cdns_i2c_probe()
1226 	pm_runtime_use_autosuspend(id->dev);  in cdns_i2c_probe()
1227 	pm_runtime_set_active(id->dev);  in cdns_i2c_probe()
1228 	pm_runtime_enable(id->dev);  in cdns_i2c_probe()
1230 	id->clk_rate_change_nb.notifier_call = cdns_i2c_clk_notifier_cb;  in cdns_i2c_probe()
1231 	if (clk_notifier_register(id->clk, &id->clk_rate_change_nb))  in cdns_i2c_probe()
1232 		dev_warn(&pdev->dev, "Unable to register clock notifier.\n");  in cdns_i2c_probe()
1233 	id->input_clk = clk_get_rate(id->clk);  in cdns_i2c_probe()
1235 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",  in cdns_i2c_probe()
1236 			&id->i2c_clk);  in cdns_i2c_probe()
1237 	if (ret || (id->i2c_clk > I2C_MAX_FAST_MODE_FREQ))  in cdns_i2c_probe()
1238 		id->i2c_clk = I2C_MAX_STANDARD_MODE_FREQ;  in cdns_i2c_probe()
1242 	id->dev_mode = CDNS_I2C_MODE_MASTER;  in cdns_i2c_probe()
1243 	id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;  in cdns_i2c_probe()
1247 	ret = cdns_i2c_setclk(id->input_clk, id);  in cdns_i2c_probe()
1249 		dev_err(&pdev->dev, "invalid SCL clock: %u Hz\n", id->i2c_clk);  in cdns_i2c_probe()
1250 		ret = -EINVAL;  in cdns_i2c_probe()
1254 	ret = devm_request_irq(&pdev->dev, id->irq, cdns_i2c_isr, 0,  in cdns_i2c_probe()
1257 		dev_err(&pdev->dev, "cannot get irq %d\n", id->irq);  in cdns_i2c_probe()
1270 	ret = i2c_add_adapter(&id->adap);  in cdns_i2c_probe()
1274 	dev_info(&pdev->dev, "%u kHz mmio %08lx irq %d\n",  in cdns_i2c_probe()
1275 		 id->i2c_clk / 1000, (unsigned long)r_mem->start, id->irq);  in cdns_i2c_probe()
1280 	clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);  in cdns_i2c_probe()
1281 	clk_disable_unprepare(id->clk);  in cdns_i2c_probe()
1282 	pm_runtime_disable(&pdev->dev);  in cdns_i2c_probe()
1283 	pm_runtime_set_suspended(&pdev->dev);  in cdns_i2c_probe()
1288  * cdns_i2c_remove - Unregister the device after releasing the resources
1299 	pm_runtime_disable(&pdev->dev);  in cdns_i2c_remove()
1300 	pm_runtime_set_suspended(&pdev->dev);  in cdns_i2c_remove()
1301 	pm_runtime_dont_use_autosuspend(&pdev->dev);  in cdns_i2c_remove()
1303 	i2c_del_adapter(&id->adap);  in cdns_i2c_remove()
1304 	clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);  in cdns_i2c_remove()
1305 	clk_disable_unprepare(id->clk);  in cdns_i2c_remove()