Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:
 "Some more driver bugfixes for I2C. Including a revert - the updated
  series for it will come during the next merge window"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: owl: Clear NACK and BUS error bits
  Revert "i2c: imx: Fix reset of I2SR_IAL flag"
  i2c: meson: fixup rate calculation with filter delay
  i2c: meson: keep peripheral clock enabled
  i2c: meson: fix clock setting overwrite
  i2c: imx: Fix reset of I2SR_IAL flag

Author: torvalds

drivers/i2c/busses/i2c-meson.c

@@ -5,6 +5,7 @@
  * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/i2c.h>
@@ -33,12 +34,17 @@
 #define REG_CTRL_ACK_IGNORE	BIT(1)
 #define REG_CTRL_STATUS		BIT(2)
 #define REG_CTRL_ERROR		BIT(3)
-#define REG_CTRL_CLKDIV_SHIFT	12
-#define REG_CTRL_CLKDIV_MASK	GENMASK(21, 12)
-#define REG_CTRL_CLKDIVEXT_SHIFT 28
-#define REG_CTRL_CLKDIVEXT_MASK	GENMASK(29, 28)
+#define REG_CTRL_CLKDIV		GENMASK(21, 12)
+#define REG_CTRL_CLKDIVEXT	GENMASK(29, 28)
+
+#define REG_SLV_ADDR		GENMASK(7, 0)
+#define REG_SLV_SDA_FILTER	GENMASK(10, 8)
+#define REG_SLV_SCL_FILTER	GENMASK(13, 11)
+#define REG_SLV_SCL_LOW		GENMASK(27, 16)
+#define REG_SLV_SCL_LOW_EN	BIT(28)
 
 #define I2C_TIMEOUT_MS		500
+#define FILTER_DELAY		15
 
 enum {
 	TOKEN_END = 0,
@@ -133,19 +139,24 @@ static void meson_i2c_set_clk_div(struct meson_i2c *i2c, unsigned int freq)
 	unsigned long clk_rate = clk_get_rate(i2c->clk);
 	unsigned int div;
 
-	div = DIV_ROUND_UP(clk_rate, freq * i2c->data->div_factor);
+	div = DIV_ROUND_UP(clk_rate, freq);
+	div -= FILTER_DELAY;
+	div = DIV_ROUND_UP(div, i2c->data->div_factor);
 
 	/* clock divider has 12 bits */
-	if (div >= (1 << 12)) {
+	if (div > GENMASK(11, 0)) {
 		dev_err(i2c->dev, "requested bus frequency too low\n");
-		div = (1 << 12) - 1;
+		div = GENMASK(11, 0);
 	}
 
-	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIV_MASK,
-			   (div & GENMASK(9, 0)) << REG_CTRL_CLKDIV_SHIFT);
+	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIV,
+			   FIELD_PREP(REG_CTRL_CLKDIV, div & GENMASK(9, 0)));
+
+	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIVEXT,
+			   FIELD_PREP(REG_CTRL_CLKDIVEXT, div >> 10));
 
-	meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIVEXT_MASK,
-			   (div >> 10) << REG_CTRL_CLKDIVEXT_SHIFT);
+	/* Disable HIGH/LOW mode */
+	meson_i2c_set_mask(i2c, REG_SLAVE_ADDR, REG_SLV_SCL_LOW_EN, 0);
 
 	dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__,
 		clk_rate, freq, div);
@@ -280,7 +291,10 @@ static void meson_i2c_do_start(struct meson_i2c *i2c, struct i2c_msg *msg)
 	token = (msg->flags & I2C_M_RD) ? TOKEN_SLAVE_ADDR_READ :
 		TOKEN_SLAVE_ADDR_WRITE;
 
-	writel(msg->addr << 1, i2c->regs + REG_SLAVE_ADDR);
+
+	meson_i2c_set_mask(i2c, REG_SLAVE_ADDR, REG_SLV_ADDR,
+			   FIELD_PREP(REG_SLV_ADDR, msg->addr << 1));
+
 	meson_i2c_add_token(i2c, TOKEN_START);
 	meson_i2c_add_token(i2c, token);
 }
@@ -357,16 +371,12 @@ static int meson_i2c_xfer_messages(struct i2c_adapter *adap,
 	struct meson_i2c *i2c = adap->algo_data;
 	int i, ret = 0;
 
-	clk_enable(i2c->clk);
-
 	for (i = 0; i < num; i++) {
 		ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1, atomic);
 		if (ret)
 			break;
 	}
 
-	clk_disable(i2c->clk);
-
 	return ret ?: i;
 }
 
@@ -435,7 +445,7 @@ static int meson_i2c_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = clk_prepare(i2c->clk);
+	ret = clk_prepare_enable(i2c->clk);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "can't prepare clock\n");
 		return ret;
@@ -457,10 +467,14 @@ static int meson_i2c_probe(struct platform_device *pdev)
 
 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret < 0) {
-		clk_unprepare(i2c->clk);
+		clk_disable_unprepare(i2c->clk);
 		return ret;
 	}
 
+	/* Disable filtering */
+	meson_i2c_set_mask(i2c, REG_SLAVE_ADDR,
+			   REG_SLV_SDA_FILTER | REG_SLV_SCL_FILTER, 0);
+
 	meson_i2c_set_clk_div(i2c, timings.bus_freq_hz);
 
 	return 0;
@@ -471,7 +485,7 @@ static int meson_i2c_remove(struct platform_device *pdev)
 	struct meson_i2c *i2c = platform_get_drvdata(pdev);
 
 	i2c_del_adapter(&i2c->adap);
-	clk_unprepare(i2c->clk);
+	clk_disable_unprepare(i2c->clk);
 
 	return 0;
 }

drivers/i2c/busses/i2c-owl.c

@@ -176,13 +176,19 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
 	fifostat = readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT);
 	if (fifostat & OWL_I2C_FIFOSTAT_RNB) {
 		i2c_dev->err = -ENXIO;
+		/* Clear NACK error bit by writing "1" */
+		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOSTAT,
+				   OWL_I2C_FIFOSTAT_RNB, true);
 		goto stop;
 	}
 
 	/* Handle bus error */
 	stat = readl(i2c_dev->base + OWL_I2C_REG_STAT);
 	if (stat & OWL_I2C_STAT_BEB) {
 		i2c_dev->err = -EIO;
+		/* Clear BUS error bit by writing "1" */
+		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,
+				   OWL_I2C_STAT_BEB, true);
 		goto stop;
 	}