1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Actions Semiconductor Owl SoC's I2C driver
6  * Author: David Liu <liuwei@actions-semi.com>
14 #include <linux/i2c.h>
21 /* I2C registers */
87 /* I2C bus timeout */
122 	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,  in owl_i2c_reset()
125 	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,  in owl_i2c_reset()
129 	writel(0, i2c_dev->base + OWL_I2C_REG_STAT);  in owl_i2c_reset()
137 	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,  in owl_i2c_reset_fifo()
143 		val = readl(i2c_dev->base + OWL_I2C_REG_FIFOCTL);  in owl_i2c_reset_fifo()
150 		dev_err(&i2c_dev->adap.dev, "FIFO reset timeout\n");  in owl_i2c_reset_fifo()
151 		return -ETIMEDOUT;  in owl_i2c_reset_fifo()
161 	val = DIV_ROUND_UP(i2c_dev->clk_rate, i2c_dev->bus_freq * 16);  in owl_i2c_set_freq()
164 	writel(OWL_I2C_DIV_FACTOR(val), i2c_dev->base + OWL_I2C_REG_CLKDIV);  in owl_i2c_set_freq()
169 	struct i2c_msg *msg = i2c_dev->msg;  in owl_i2c_xfer_data()
172 	i2c_dev->err = 0;  in owl_i2c_xfer_data()
175 	fifostat = readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT);  in owl_i2c_xfer_data()
177 		i2c_dev->err = -ENXIO;  in owl_i2c_xfer_data()
179 		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOSTAT,  in owl_i2c_xfer_data()
185 	stat = readl(i2c_dev->base + OWL_I2C_REG_STAT);  in owl_i2c_xfer_data()
187 		i2c_dev->err = -EIO;  in owl_i2c_xfer_data()
189 		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,  in owl_i2c_xfer_data()
195 	if (msg->flags & I2C_M_RD) {  in owl_i2c_xfer_data()
196 		while ((readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &  in owl_i2c_xfer_data()
197 			OWL_I2C_FIFOSTAT_RFE) && i2c_dev->msg_ptr < msg->len) {  in owl_i2c_xfer_data()
198 			msg->buf[i2c_dev->msg_ptr++] = readl(i2c_dev->base +  in owl_i2c_xfer_data()
203 		while (!(readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &  in owl_i2c_xfer_data()
204 			 OWL_I2C_FIFOSTAT_TFF) && i2c_dev->msg_ptr < msg->len) {  in owl_i2c_xfer_data()
205 			writel(msg->buf[i2c_dev->msg_ptr++],  in owl_i2c_xfer_data()
206 			       i2c_dev->base + OWL_I2C_REG_TXDAT);  in owl_i2c_xfer_data()
215 	spin_lock(&i2c_dev->lock);  in owl_i2c_interrupt()
220 	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,  in owl_i2c_interrupt()
223 	complete_all(&i2c_dev->msg_complete);  in owl_i2c_interrupt()
224 	spin_unlock(&i2c_dev->lock);  in owl_i2c_interrupt()
241 	while (readl(i2c_dev->base + OWL_I2C_REG_STAT) & OWL_I2C_STAT_BBB) {  in owl_i2c_check_bus_busy()
243 			dev_err(&adap->dev, "Bus busy timeout\n");  in owl_i2c_check_bus_busy()
244 			return -ETIMEDOUT;  in owl_i2c_check_bus_busy()
261 	spin_lock_irqsave(&i2c_dev->lock, flags);  in owl_i2c_xfer_common()
263 	/* Reset I2C controller */  in owl_i2c_xfer_common()
273 	spin_unlock_irqrestore(&i2c_dev->lock, flags);  in owl_i2c_xfer_common()
285 	spin_lock_irqsave(&i2c_dev->lock, flags);  in owl_i2c_xfer_common()
288 	val = readl(i2c_dev->base + OWL_I2C_REG_STAT);  in owl_i2c_xfer_common()
291 		writel(val, i2c_dev->base + OWL_I2C_REG_STAT);  in owl_i2c_xfer_common()
292 		ret = -EAGAIN;  in owl_i2c_xfer_common()
297 		reinit_completion(&i2c_dev->msg_complete);  in owl_i2c_xfer_common()
299 	/* Enable/disable I2C controller interrupt */  in owl_i2c_xfer_common()
300 	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,  in owl_i2c_xfer_common()
318 		writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT);  in owl_i2c_xfer_common()
323 			       i2c_dev->base + OWL_I2C_REG_TXDAT);  in owl_i2c_xfer_common()
332 	i2c_dev->msg = msg;  in owl_i2c_xfer_common()
333 	i2c_dev->msg_ptr = 0;  in owl_i2c_xfer_common()
336 	writel(msg->len, i2c_dev->base + OWL_I2C_REG_DATCNT);  in owl_i2c_xfer_common()
339 	writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT);  in owl_i2c_xfer_common()
341 	if (!(msg->flags & I2C_M_RD)) {  in owl_i2c_xfer_common()
343 		for (idx = 0; idx < msg->len; idx++) {  in owl_i2c_xfer_common()
345 			if (readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &  in owl_i2c_xfer_common()
349 			writel(msg->buf[idx],  in owl_i2c_xfer_common()
350 			       i2c_dev->base + OWL_I2C_REG_TXDAT);  in owl_i2c_xfer_common()
353 		i2c_dev->msg_ptr = idx;  in owl_i2c_xfer_common()
357 	if (msg->flags & I2C_M_IGNORE_NAK)  in owl_i2c_xfer_common()
358 		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,  in owl_i2c_xfer_common()
361 		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,  in owl_i2c_xfer_common()
365 	writel(i2c_cmd, i2c_dev->base + OWL_I2C_REG_CMD);  in owl_i2c_xfer_common()
367 	spin_unlock_irqrestore(&i2c_dev->lock, flags);  in owl_i2c_xfer_common()
371 		ret = readl_poll_timeout_atomic(i2c_dev->base + OWL_I2C_REG_FIFOSTAT,  in owl_i2c_xfer_common()
376 		time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,  in owl_i2c_xfer_common()
377 							adap->timeout);  in owl_i2c_xfer_common()
379 			ret = -ETIMEDOUT;  in owl_i2c_xfer_common()
382 	spin_lock_irqsave(&i2c_dev->lock, flags);  in owl_i2c_xfer_common()
385 		dev_err(&adap->dev, "Transaction timed out\n");  in owl_i2c_xfer_common()
387 		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,  in owl_i2c_xfer_common()
396 	ret = i2c_dev->err < 0 ? i2c_dev->err : num;  in owl_i2c_xfer_common()
399 	spin_unlock_irqrestore(&i2c_dev->lock, flags);  in owl_i2c_xfer_common()
402 	/* Disable I2C controller */  in owl_i2c_xfer_common()
403 	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,  in owl_i2c_xfer_common()
437 	struct device *dev = &pdev->dev;  in owl_i2c_probe()
443 		return -ENOMEM;  in owl_i2c_probe()
445 	i2c_dev->base = devm_platform_ioremap_resource(pdev, 0);  in owl_i2c_probe()
446 	if (IS_ERR(i2c_dev->base))  in owl_i2c_probe()
447 		return PTR_ERR(i2c_dev->base);  in owl_i2c_probe()
453 	if (of_property_read_u32(dev->of_node, "clock-frequency",  in owl_i2c_probe()
454 				 &i2c_dev->bus_freq))  in owl_i2c_probe()
455 		i2c_dev->bus_freq = I2C_MAX_STANDARD_MODE_FREQ;  in owl_i2c_probe()
458 	if (i2c_dev->bus_freq != I2C_MAX_STANDARD_MODE_FREQ &&  in owl_i2c_probe()
459 	    i2c_dev->bus_freq != I2C_MAX_FAST_MODE_FREQ) {  in owl_i2c_probe()
460 		dev_err(dev, "invalid clock-frequency %d\n", i2c_dev->bus_freq);  in owl_i2c_probe()
461 		return -EINVAL;  in owl_i2c_probe()
464 	i2c_dev->clk = devm_clk_get(dev, NULL);  in owl_i2c_probe()
465 	if (IS_ERR(i2c_dev->clk)) {  in owl_i2c_probe()
467 		return PTR_ERR(i2c_dev->clk);  in owl_i2c_probe()
470 	ret = clk_prepare_enable(i2c_dev->clk);  in owl_i2c_probe()
474 	i2c_dev->clk_rate = clk_get_rate(i2c_dev->clk);  in owl_i2c_probe()
475 	if (!i2c_dev->clk_rate) {  in owl_i2c_probe()
477 		ret = -EINVAL;  in owl_i2c_probe()
481 	init_completion(&i2c_dev->msg_complete);  in owl_i2c_probe()
482 	spin_lock_init(&i2c_dev->lock);  in owl_i2c_probe()
483 	i2c_dev->adap.owner = THIS_MODULE;  in owl_i2c_probe()
484 	i2c_dev->adap.algo = &owl_i2c_algorithm;  in owl_i2c_probe()
485 	i2c_dev->adap.timeout = OWL_I2C_TIMEOUT;  in owl_i2c_probe()
486 	i2c_dev->adap.quirks = &owl_i2c_quirks;  in owl_i2c_probe()
487 	i2c_dev->adap.dev.parent = dev;  in owl_i2c_probe()
488 	i2c_dev->adap.dev.of_node = dev->of_node;  in owl_i2c_probe()
489 	snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),  in owl_i2c_probe()
490 		 "%s", "OWL I2C adapter");  in owl_i2c_probe()
491 	i2c_set_adapdata(&i2c_dev->adap, i2c_dev);  in owl_i2c_probe()
495 	ret = devm_request_irq(dev, irq, owl_i2c_interrupt, 0, pdev->name,  in owl_i2c_probe()
502 	return i2c_add_adapter(&i2c_dev->adap);  in owl_i2c_probe()
505 	clk_disable_unprepare(i2c_dev->clk);  in owl_i2c_probe()
511 	{ .compatible = "actions,s500-i2c" },
512 	{ .compatible = "actions,s700-i2c" },
513 	{ .compatible = "actions,s900-i2c" },
521 		.name	= "owl-i2c",
528 MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>");
530 MODULE_DESCRIPTION("Actions Semiconductor Owl SoC's I2C driver");