1 // SPDX-License-Identifier: GPL-2.0
8 #include <linux/clk-provider.h>
27  * 16-bit field for the number of SCL cycles to wait after rising SCL
76 	writel(val, i2c_dev->regs + reg);  in bcm2835_i2c_writel()
81 	return readl(i2c_dev->regs + reg);  in bcm2835_i2c_readl()
104 		return -EINVAL;  in clk_bcm2835_i2c_calc_divider()
112 	struct clk_bcm2835_i2c *div = to_clk_bcm2835_i2c(hw);  in clk_bcm2835_i2c_set_rate()  local
116 	if (divider == -EINVAL)  in clk_bcm2835_i2c_set_rate()
117 		return -EINVAL;  in clk_bcm2835_i2c_set_rate()
119 	bcm2835_i2c_writel(div->i2c_dev, BCM2835_I2C_DIV, divider);  in clk_bcm2835_i2c_set_rate()
134 	bcm2835_i2c_writel(div->i2c_dev, BCM2835_I2C_DEL,  in clk_bcm2835_i2c_set_rate()
151 	struct clk_bcm2835_i2c *div = to_clk_bcm2835_i2c(hw);  in clk_bcm2835_i2c_recalc_rate()  local
152 	u32 divider = bcm2835_i2c_readl(div->i2c_dev, BCM2835_I2C_DIV);  in clk_bcm2835_i2c_recalc_rate()
164 					struct clk *mclk,  in bcm2835_i2c_register_div()  argument
174 	mclk_name = __clk_get_name(mclk);  in bcm2835_i2c_register_div()
184 		return ERR_PTR(-ENOMEM);  in bcm2835_i2c_register_div()
186 	priv->hw.init = &init;  in bcm2835_i2c_register_div()
187 	priv->i2c_dev = i2c_dev;  in bcm2835_i2c_register_div()
189 	clk_hw_register_clkdev(&priv->hw, "div", dev_name(dev));  in bcm2835_i2c_register_div()
190 	return devm_clk_register(dev, &priv->hw);  in bcm2835_i2c_register_div()
197 	while (i2c_dev->msg_buf_remaining) {  in bcm2835_fill_txfifo()
202 				   *i2c_dev->msg_buf);  in bcm2835_fill_txfifo()
203 		i2c_dev->msg_buf++;  in bcm2835_fill_txfifo()
204 		i2c_dev->msg_buf_remaining--;  in bcm2835_fill_txfifo()
212 	while (i2c_dev->msg_buf_remaining) {  in bcm2835_drain_rxfifo()
216 		*i2c_dev->msg_buf = bcm2835_i2c_readl(i2c_dev,  in bcm2835_drain_rxfifo()
218 		i2c_dev->msg_buf++;  in bcm2835_drain_rxfifo()
219 		i2c_dev->msg_buf_remaining--;  in bcm2835_drain_rxfifo()
239 	struct i2c_msg *msg = i2c_dev->curr_msg;  in bcm2835_i2c_start_transfer()
240 	bool last_msg = (i2c_dev->num_msgs == 1);  in bcm2835_i2c_start_transfer()
242 	if (!i2c_dev->num_msgs)  in bcm2835_i2c_start_transfer()
245 	i2c_dev->num_msgs--;  in bcm2835_i2c_start_transfer()
246 	i2c_dev->msg_buf = msg->buf;  in bcm2835_i2c_start_transfer()
247 	i2c_dev->msg_buf_remaining = msg->len;  in bcm2835_i2c_start_transfer()
249 	if (msg->flags & I2C_M_RD)  in bcm2835_i2c_start_transfer()
257 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_A, msg->addr);  in bcm2835_i2c_start_transfer()
258 	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_DLEN, msg->len);  in bcm2835_i2c_start_transfer()
264 	i2c_dev->curr_msg = NULL;  in bcm2835_i2c_finish_transfer()
265 	i2c_dev->num_msgs = 0;  in bcm2835_i2c_finish_transfer()
267 	i2c_dev->msg_buf = NULL;  in bcm2835_i2c_finish_transfer()
268 	i2c_dev->msg_buf_remaining = 0;  in bcm2835_i2c_finish_transfer()
273  * The I2C_C_CLEAR on errors will take some time to resolve -- if you were in
274  * non-idle state and I2C_C_READ, it sets an abort_rx flag and runs through
289 		i2c_dev->msg_err = err;  in bcm2835_i2c_isr()
294 		if (!i2c_dev->curr_msg) {  in bcm2835_i2c_isr()
295 			dev_err(i2c_dev->dev, "Got unexpected interrupt (from firmware?)\n");  in bcm2835_i2c_isr()
296 		} else if (i2c_dev->curr_msg->flags & I2C_M_RD) {  in bcm2835_i2c_isr()
301 		if ((val & BCM2835_I2C_S_RXD) || i2c_dev->msg_buf_remaining)  in bcm2835_i2c_isr()
302 			i2c_dev->msg_err = BCM2835_I2C_S_LEN;  in bcm2835_i2c_isr()
304 			i2c_dev->msg_err = 0;  in bcm2835_i2c_isr()
309 		if (!i2c_dev->msg_buf_remaining) {  in bcm2835_i2c_isr()
310 			i2c_dev->msg_err = val | BCM2835_I2C_S_LEN;  in bcm2835_i2c_isr()
316 		if (i2c_dev->num_msgs && !i2c_dev->msg_buf_remaining) {  in bcm2835_i2c_isr()
317 			i2c_dev->curr_msg++;  in bcm2835_i2c_isr()
325 		if (!i2c_dev->msg_buf_remaining) {  in bcm2835_i2c_isr()
326 			i2c_dev->msg_err = val | BCM2835_I2C_S_LEN;  in bcm2835_i2c_isr()
340 	complete(&i2c_dev->completion);  in bcm2835_i2c_isr()
352 	for (i = 0; i < (num - 1); i++)  in bcm2835_i2c_xfer()
354 			dev_warn_once(i2c_dev->dev,  in bcm2835_i2c_xfer()
356 			return -EOPNOTSUPP;  in bcm2835_i2c_xfer()
359 	i2c_dev->curr_msg = msgs;  in bcm2835_i2c_xfer()
360 	i2c_dev->num_msgs = num;  in bcm2835_i2c_xfer()
361 	reinit_completion(&i2c_dev->completion);  in bcm2835_i2c_xfer()
365 	time_left = wait_for_completion_timeout(&i2c_dev->completion,  in bcm2835_i2c_xfer()
366 						adap->timeout);  in bcm2835_i2c_xfer()
373 		return -ETIMEDOUT;  in bcm2835_i2c_xfer()
376 	if (!i2c_dev->msg_err)  in bcm2835_i2c_xfer()
379 	dev_dbg(i2c_dev->dev, "i2c transfer failed: %x\n", i2c_dev->msg_err);  in bcm2835_i2c_xfer()
381 	if (i2c_dev->msg_err & BCM2835_I2C_S_ERR)  in bcm2835_i2c_xfer()
382 		return -EREMOTEIO;  in bcm2835_i2c_xfer()
384 	return -EIO;  in bcm2835_i2c_xfer()
399  * https://www.advamation.com/knowhow/raspberrypi/rpi-i2c-bug.html
411 	struct clk *mclk;  in bcm2835_i2c_probe()  local
414 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);  in bcm2835_i2c_probe()
416 		return -ENOMEM;  in bcm2835_i2c_probe()
418 	i2c_dev->dev = &pdev->dev;  in bcm2835_i2c_probe()
419 	init_completion(&i2c_dev->completion);  in bcm2835_i2c_probe()
421 	i2c_dev->regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);  in bcm2835_i2c_probe()
422 	if (IS_ERR(i2c_dev->regs))  in bcm2835_i2c_probe()
423 		return PTR_ERR(i2c_dev->regs);  in bcm2835_i2c_probe()
425 	mclk = devm_clk_get(&pdev->dev, NULL);  in bcm2835_i2c_probe()
426 	if (IS_ERR(mclk))  in bcm2835_i2c_probe()
427 		return dev_err_probe(&pdev->dev, PTR_ERR(mclk),  in bcm2835_i2c_probe()
430 	i2c_dev->bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);  in bcm2835_i2c_probe()
432 	if (IS_ERR(i2c_dev->bus_clk))  in bcm2835_i2c_probe()
433 		return dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->bus_clk),  in bcm2835_i2c_probe()
436 	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",  in bcm2835_i2c_probe()
439 		dev_warn(&pdev->dev,  in bcm2835_i2c_probe()
440 			 "Could not read clock-frequency property\n");  in bcm2835_i2c_probe()
444 	ret = clk_set_rate_exclusive(i2c_dev->bus_clk, bus_clk_rate);  in bcm2835_i2c_probe()
446 		return dev_err_probe(&pdev->dev, ret,  in bcm2835_i2c_probe()
449 	ret = clk_prepare_enable(i2c_dev->bus_clk);  in bcm2835_i2c_probe()
451 		dev_err(&pdev->dev, "Couldn't prepare clock");  in bcm2835_i2c_probe()
455 	i2c_dev->irq = platform_get_irq(pdev, 0);  in bcm2835_i2c_probe()
456 	if (i2c_dev->irq < 0) {  in bcm2835_i2c_probe()
457 		ret = i2c_dev->irq;  in bcm2835_i2c_probe()
461 	ret = request_irq(i2c_dev->irq, bcm2835_i2c_isr, IRQF_SHARED,  in bcm2835_i2c_probe()
462 			  dev_name(&pdev->dev), i2c_dev);  in bcm2835_i2c_probe()
464 		dev_err(&pdev->dev, "Could not request IRQ\n");  in bcm2835_i2c_probe()
468 	adap = &i2c_dev->adapter;  in bcm2835_i2c_probe()
470 	adap->owner = THIS_MODULE;  in bcm2835_i2c_probe()
471 	adap->class = I2C_CLASS_DEPRECATED;  in bcm2835_i2c_probe()
472 	snprintf(adap->name, sizeof(adap->name), "bcm2835 (%s)",  in bcm2835_i2c_probe()
473 		 of_node_full_name(pdev->dev.of_node));  in bcm2835_i2c_probe()
474 	adap->algo = &bcm2835_i2c_algo;  in bcm2835_i2c_probe()
475 	adap->dev.parent = &pdev->dev;  in bcm2835_i2c_probe()
476 	adap->dev.of_node = pdev->dev.of_node;  in bcm2835_i2c_probe()
477 	adap->quirks = of_device_get_match_data(&pdev->dev);  in bcm2835_i2c_probe()
494 	free_irq(i2c_dev->irq, i2c_dev);  in bcm2835_i2c_probe()
496 	clk_disable_unprepare(i2c_dev->bus_clk);  in bcm2835_i2c_probe()
498 	clk_rate_exclusive_put(i2c_dev->bus_clk);  in bcm2835_i2c_probe()
507 	clk_rate_exclusive_put(i2c_dev->bus_clk);  in bcm2835_i2c_remove()
508 	clk_disable_unprepare(i2c_dev->bus_clk);  in bcm2835_i2c_remove()
510 	free_irq(i2c_dev->irq, i2c_dev);  in bcm2835_i2c_remove()
511 	i2c_del_adapter(&i2c_dev->adapter);  in bcm2835_i2c_remove()
515 	{ .compatible = "brcm,bcm2711-i2c" },
516 	{ .compatible = "brcm,bcm2835-i2c", .data = &bcm2835_i2c_quirks },
525 		.name	= "i2c-bcm2835",
534 MODULE_ALIAS("platform:i2c-bcm2835");