1 // SPDX-License-Identifier: GPL-2.0-only
3  * Loongson-2K/Loongson LS7A I2C controller mode driver
5  * Copyright (C) 2013 Loongson Technology Corporation Limited.
6  * Copyright (C) 2014-2017 Lemote, Inc.
7  * Copyright (C) 2018-2022 Loongson Technology Corporation Limited.
10  * Rewritten for mainline by Binbin Zhou <zhoubinbin@loongson.cn>
48 #define LS2X_SR_TIP		BIT(1) /* Transmission state */
52 #define LS2X_CTR_EN		BIT(7) /* 0: I2c frequency setting 1: Normal */
54 #define LS2X_CTR_MST		BIT(5) /* 0: Target mode 1: Controller mode */
79 	if (!(readb(priv->base + I2C_LS2X_SR) & LS2X_SR_IF))  in ls2x_i2c_isr()
82 	writeb(LS2X_CR_IACK, priv->base + I2C_LS2X_CR);  in ls2x_i2c_isr()
83 	complete(&priv->cmd_complete);  in ls2x_i2c_isr()
96 	struct i2c_timings *t = &priv->i2c_t;  in ls2x_i2c_adjust_bus_speed()
97 	struct device *dev = priv->adapter.dev.parent;  in ls2x_i2c_adjust_bus_speed()
102 	if (acpi_speed || t->bus_freq_hz)  in ls2x_i2c_adjust_bus_speed()
103 		t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed);  in ls2x_i2c_adjust_bus_speed()
105 		t->bus_freq_hz = LS2X_I2C_FREQ_STD;  in ls2x_i2c_adjust_bus_speed()
108 	writew(LS2X_I2C_PCLK_FREQ / (5 * t->bus_freq_hz) - 1,  in ls2x_i2c_adjust_bus_speed()
109 	       priv->base + I2C_LS2X_PRER);  in ls2x_i2c_adjust_bus_speed()
115 	writeb(readb(priv->base + I2C_LS2X_CTR) & ~CTR_FREQ_MASK,  in ls2x_i2c_init()
116 	       priv->base + I2C_LS2X_CTR);  in ls2x_i2c_init()
121 	writeb(readb(priv->base + I2C_LS2X_CTR) | CTR_READY_MASK,  in ls2x_i2c_init()
122 	       priv->base + I2C_LS2X_CTR);  in ls2x_i2c_init()
130 	writeb(txdata, priv->base + I2C_LS2X_CR);  in ls2x_i2c_xfer_byte()
132 	time_left = wait_for_completion_timeout(&priv->cmd_complete,  in ls2x_i2c_xfer_byte()
133 						priv->adapter.timeout);  in ls2x_i2c_xfer_byte()
135 		return -ETIMEDOUT;  in ls2x_i2c_xfer_byte()
137 	rxdata = readb(priv->base + I2C_LS2X_SR);  in ls2x_i2c_xfer_byte()
154 		return -EAGAIN;  in ls2x_i2c_send_byte()
157 		return -ENXIO;  in ls2x_i2c_send_byte()
166 	writeb(LS2X_CR_STOP, priv->base + I2C_LS2X_CR);  in ls2x_i2c_stop()
167 	return readb_poll_timeout(priv->base + I2C_LS2X_SR, value,  in ls2x_i2c_stop()
169 				  jiffies_to_usecs(priv->adapter.timeout));  in ls2x_i2c_stop()
174 	reinit_completion(&priv->cmd_complete);  in ls2x_i2c_start()
176 	writeb(i2c_8bit_addr_from_msg(msgs), priv->base + I2C_LS2X_TXR);  in ls2x_i2c_start()
183 	u8 rxdata, *buf = msg->buf;  in ls2x_i2c_rx()
184 	u16 len = msg->len;  in ls2x_i2c_rx()
191 	while (len--) {  in ls2x_i2c_rx()
198 		*buf++ = readb(priv->base + I2C_LS2X_RXR);  in ls2x_i2c_rx()
207 	u8 *buf = msg->buf;  in ls2x_i2c_tx()
208 	u16 len = msg->len;  in ls2x_i2c_tx()
215 	while (len--) {  in ls2x_i2c_tx()
216 		writeb(*buf++, priv->base + I2C_LS2X_TXR);  in ls2x_i2c_tx()
231 	if (msg->flags & I2C_M_RD)  in ls2x_i2c_xfer_one()
238 		if (ret == -ETIMEDOUT)  in ls2x_i2c_xfer_one()
261 		ret = ls2x_i2c_xfer_one(priv, msg, msg == emsg - 1);  in ls2x_i2c_xfer()
284 	struct device *dev = &pdev->dev;  in ls2x_i2c_probe()
288 		return -ENOMEM;  in ls2x_i2c_probe()
291 	priv->base = devm_platform_ioremap_resource(pdev, 0);  in ls2x_i2c_probe()
292 	if (IS_ERR(priv->base))  in ls2x_i2c_probe()
293 		return PTR_ERR(priv->base);  in ls2x_i2c_probe()
300 	adap = &priv->adapter;  in ls2x_i2c_probe()
301 	adap->retries = 5;  in ls2x_i2c_probe()
302 	adap->nr = pdev->id;  in ls2x_i2c_probe()
303 	adap->dev.parent = dev;  in ls2x_i2c_probe()
304 	adap->owner = THIS_MODULE;  in ls2x_i2c_probe()
305 	adap->algo = &ls2x_i2c_algo;  in ls2x_i2c_probe()
306 	adap->timeout = msecs_to_jiffies(100);  in ls2x_i2c_probe()
307 	device_set_node(&adap->dev, dev_fwnode(dev));  in ls2x_i2c_probe()
309 	strscpy(adap->name, pdev->name, sizeof(adap->name));  in ls2x_i2c_probe()
310 	init_completion(&priv->cmd_complete);  in ls2x_i2c_probe()
315 	ret = devm_request_irq(dev, irq, ls2x_i2c_isr, IRQF_SHARED, "ls2x-i2c",  in ls2x_i2c_probe()
328 	writeb(readb(priv->base + I2C_LS2X_CTR) & ~LS2X_CTR_IEN,  in ls2x_i2c_suspend()
329 	       priv->base + I2C_LS2X_CTR);  in ls2x_i2c_suspend()
344 	{ .compatible = "loongson,ls2k-i2c" },
345 	{ .compatible = "loongson,ls7a-i2c" },
351 	{ "LOON0004" }, /* Loongson LS7A */
359 		.name	= "ls2x-i2c",
367 MODULE_DESCRIPTION("Loongson LS2X I2C Bus driver");
368 MODULE_AUTHOR("Loongson Technology Corporation Limited");