1 // SPDX-License-Identifier: GPL-2.0-or-later
16 #define     UNIPHIER_I2C_DTRM_STO	BIT(9)	/* stop condition */
17 #define     UNIPHIER_I2C_DTRM_NACK	BIT(8)	/* do not return ACK */
22 #define     UNIPHIER_I2C_DREC_STS	BIT(12)	/* stop condition detected */
23 #define     UNIPHIER_I2C_DREC_LRB	BIT(11)	/* no ACK */
56 	complete(&priv->comp);  in uniphier_i2c_interrupt()
68 	reinit_completion(&priv->comp);  in uniphier_i2c_xfer_byte()
71 	writel(txdata, priv->membase + UNIPHIER_I2C_DTRM);  in uniphier_i2c_xfer_byte()
73 	time_left = wait_for_completion_timeout(&priv->comp, adap->timeout);  in uniphier_i2c_xfer_byte()
75 		return -ETIMEDOUT;  in uniphier_i2c_xfer_byte()
77 	rxdata = readl(priv->membase + UNIPHIER_I2C_DREC);  in uniphier_i2c_xfer_byte()
94 		return -EAGAIN;  in uniphier_i2c_send_byte()
97 		return -ENXIO;  in uniphier_i2c_send_byte()
113 	while (len--) {  in uniphier_i2c_tx()
135 	while (len--) {  in uniphier_i2c_rx()
156 				 struct i2c_msg *msg, bool stop)  in uniphier_i2c_xfer_one()  argument
158 	bool is_read = msg->flags & I2C_M_RD;  in uniphier_i2c_xfer_one()
163 		ret = uniphier_i2c_rx(adap, msg->addr, msg->len, msg->buf);  in uniphier_i2c_xfer_one()
165 		ret = uniphier_i2c_tx(adap, msg->addr, msg->len, msg->buf);  in uniphier_i2c_xfer_one()
167 	if (ret == -EAGAIN) /* could not acquire bus. bail out without STOP */  in uniphier_i2c_xfer_one()
170 	if (ret == -ETIMEDOUT) {  in uniphier_i2c_xfer_one()
172 		stop = false;  in uniphier_i2c_xfer_one()
176 	if (stop) {  in uniphier_i2c_xfer_one()
180 			/* Failed to issue STOP.  The bus needs recovery. */  in uniphier_i2c_xfer_one()
196 	if (!(readl(priv->membase + UNIPHIER_I2C_DREC) &  in uniphier_i2c_check_bus_busy()
198 		if (priv->busy_cnt++ > 3) {  in uniphier_i2c_check_bus_busy()
204 			priv->busy_cnt = 0;  in uniphier_i2c_check_bus_busy()
207 		return -EAGAIN;  in uniphier_i2c_check_bus_busy()
210 	priv->busy_cnt = 0;  in uniphier_i2c_check_bus_busy()
224 		/* Emit STOP if it is the last message or I2C_M_STOP is set. */  in uniphier_i2c_xfer()
225 		bool stop = (msg + 1 == emsg) || (msg->flags & I2C_M_STOP);  in uniphier_i2c_xfer()  local
227 		ret = uniphier_i2c_xfer_one(adap, msg, stop);  in uniphier_i2c_xfer()
250 	writel(val, priv->membase + UNIPHIER_I2C_BRST);  in uniphier_i2c_reset()
257 	return !!(readl(priv->membase + UNIPHIER_I2C_BSTS) &  in uniphier_i2c_get_scl()
266 	       priv->membase + UNIPHIER_I2C_BRST);  in uniphier_i2c_set_scl()
273 	return !!(readl(priv->membase + UNIPHIER_I2C_BSTS) &  in uniphier_i2c_get_sda()
292 	unsigned int cyc = priv->clk_cycle;  in uniphier_i2c_hw_init()
297 	 * Bit30-16: clock cycles of tLOW.  in uniphier_i2c_hw_init()
298 	 *  Standard-mode: tLOW = 4.7 us, tHIGH = 4.0 us  in uniphier_i2c_hw_init()
299 	 *  Fast-mode:     tLOW = 1.3 us, tHIGH = 0.6 us  in uniphier_i2c_hw_init()
302 	writel((cyc * 5 / 9 << 16) | cyc, priv->membase + UNIPHIER_I2C_CLK);  in uniphier_i2c_hw_init()
309 	struct device *dev = &pdev->dev;  in uniphier_i2c_probe()
317 		return -ENOMEM;  in uniphier_i2c_probe()
319 	priv->membase = devm_platform_ioremap_resource(pdev, 0);  in uniphier_i2c_probe()
320 	if (IS_ERR(priv->membase))  in uniphier_i2c_probe()
321 		return PTR_ERR(priv->membase);  in uniphier_i2c_probe()
327 	if (of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed))  in uniphier_i2c_probe()
331 		return dev_err_probe(dev, -EINVAL, "invalid clock-frequency %d\n", bus_speed);  in uniphier_i2c_probe()
333 	priv->clk = devm_clk_get_enabled(dev, NULL);  in uniphier_i2c_probe()
334 	if (IS_ERR(priv->clk))  in uniphier_i2c_probe()
335 		return dev_err_probe(dev, PTR_ERR(priv->clk), "failed to enable clock\n");  in uniphier_i2c_probe()
337 	clk_rate = clk_get_rate(priv->clk);  in uniphier_i2c_probe()
339 		return dev_err_probe(dev, -EINVAL, "input clock rate should not be zero\n");  in uniphier_i2c_probe()
341 	priv->clk_cycle = clk_rate / bus_speed;  in uniphier_i2c_probe()
342 	init_completion(&priv->comp);  in uniphier_i2c_probe()
343 	priv->adap.owner = THIS_MODULE;  in uniphier_i2c_probe()
344 	priv->adap.algo = &uniphier_i2c_algo;  in uniphier_i2c_probe()
345 	priv->adap.dev.parent = dev;  in uniphier_i2c_probe()
346 	priv->adap.dev.of_node = dev->of_node;  in uniphier_i2c_probe()
347 	strscpy(priv->adap.name, "UniPhier I2C", sizeof(priv->adap.name));  in uniphier_i2c_probe()
348 	priv->adap.bus_recovery_info = &uniphier_i2c_bus_recovery_info;  in uniphier_i2c_probe()
349 	i2c_set_adapdata(&priv->adap, priv);  in uniphier_i2c_probe()
354 	ret = devm_request_irq(dev, irq, uniphier_i2c_interrupt, 0, pdev->name,  in uniphier_i2c_probe()
359 	return i2c_add_adapter(&priv->adap);  in uniphier_i2c_probe()
366 	i2c_del_adapter(&priv->adap);  in uniphier_i2c_remove()
373 	clk_disable_unprepare(priv->clk);  in uniphier_i2c_suspend()
383 	ret = clk_prepare_enable(priv->clk);  in uniphier_i2c_resume()
397 	{ .compatible = "socionext,uniphier-i2c" },
406 		.name  = "uniphier-i2c",