Merge branch 'i2c/for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - mainly feature additions to drivers (stm32f7, qup, xlp9xx, mlxcpld, ...)

 - conversion to use the i2c_8bit_addr_from_msg macro consistently

 - move includes to platform_data

 - core updates to allow the (still in review) I3C subsystem to connect

 - and the regular share of smaller driver updates

* 'i2c/for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (68 commits)
  i2c: qup: fix building without CONFIG_ACPI
  i2c: tegra: Remove suspend-resume
  i2c: imx-lpi2c: Switch to SPDX identifier
  i2c: mxs: Switch to SPDX identifier
  i2c: busses: make use of i2c_8bit_addr_from_msg
  i2c: algos: make use of i2c_8bit_addr_from_msg
  i2c: rcar: document R8A77980 bindings
  i2c: qup: Add command-line parameter to override SCL frequency
  i2c: qup: Correct duty cycle for FM and FM+
  i2c: qup: Add support for Fast Mode Plus
  i2c: qup: add probe path for Centriq ACPI devices
  i2c: robotfuzz-osif: drop pointless test
  i2c: robotfuzz-osif: remove pointless local variable
  i2c: rk3x: Don't print visible virtual mapping MMIO address
  i2c: opal: don't check number of messages in the driver
  i2c: ibm_iic: don't check number of messages in the driver
  i2c: imx: Switch to SPDX identifier
  i2c: mux: pca954x: merge calls to of_match_device and of_device_get_match_data
  i2c: mux: demux-pinctrl: use proper parent device for demux adapter
  i2c: mux: improve error message for failed symlink
  ...

1 files changed, 68 insertions, 21 deletions

diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c
index eb8913eba0c5..1f41a4f89c08 100644
--- a/drivers/i2c/busses/i2c-xlp9xx.c
+++ b/drivers/i2c/busses/i2c-xlp9xx.c
@@ -10,6 +10,7 @@
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -84,6 +85,8 @@ struct xlp9xx_i2c_dev {
 	struct device *dev;
 	struct i2c_adapter adapter;
 	struct completion msg_complete;
+	struct i2c_smbus_alert_setup alert_data;
+	struct i2c_client *ara;
 	int irq;
 	bool msg_read;
 	bool len_recv;
@@ -155,9 +158,30 @@ static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv)
 	priv->msg_buf += len;
 }
 
+static void xlp9xx_i2c_update_rlen(struct xlp9xx_i2c_dev *priv)
+{
+	u32 val, len;
+
+	/*
+	 * Update receive length. Re-read len to get the latest value,
+	 * and then add 4 to have a minimum value that can be safely
+	 * written. This is to account for the byte read above, the
+	 * transfer in progress and any delays in the register I/O
+	 */
+	val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
+	len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
+				  XLP9XX_I2C_FIFO_WCNT_MASK;
+	len = max_t(u32, priv->msg_len, len + 4);
+	if (len >= I2C_SMBUS_BLOCK_MAX + 2)
+		return;
+	val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
+			(len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
+	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
+}
+
 static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
 {
-	u32 len, i, val;
+	u32 len, i;
 	u8 rlen, *buf = priv->msg_buf;
 
 	len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) &
@@ -167,21 +191,20 @@ static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv)
 	if (priv->len_recv) {
 		/* read length byte */
 		rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO);
-		*buf++ = rlen;
-		len--;
-
-		if (priv->client_pec)
-			++rlen;
-		/* update remaining bytes and message length */
-		priv->msg_buf_remaining = rlen;
-		priv->msg_len = rlen + 1;
+		if (rlen > I2C_SMBUS_BLOCK_MAX || rlen == 0) {
+			rlen = 0;	/*abort transfer */
+			priv->msg_buf_remaining = 0;
+			priv->msg_len = 0;
+		} else {
+			*buf++ = rlen;
+			if (priv->client_pec)
+				++rlen; /* account for error check byte */
+			/* update remaining bytes and message length */
+			priv->msg_buf_remaining = rlen;
+			priv->msg_len = rlen + 1;
+		}
+		xlp9xx_i2c_update_rlen(priv);
 		priv->len_recv = false;
-
-		/* Update transfer length to read only actual data */
-		val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL);
-		val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
-			((rlen + 1) << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
-		xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val);
 	} else {
 		len = min(priv->msg_buf_remaining, len);
 		for (i = 0; i < len; i++, buf++)
@@ -300,10 +323,6 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg,
 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL,
 			     XLP9XX_I2C_MFIFOCTRL_RST);
 
-	/* set FIFO threshold if reading */
-	if (priv->msg_read)
-		xlp9xx_i2c_update_rx_fifo_thres(priv);
-
 	/* set slave addr */
 	xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_SLAVEADDR,
 			     (msg->addr << XLP9XX_I2C_SLAVEADDR_ADDR_SHIFT) |
@@ -322,9 +341,13 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg,
 		val &= ~XLP9XX_I2C_CTRL_ADDMODE;
 
 	priv->len_recv = msg->flags & I2C_M_RECV_LEN;
-	len = priv->len_recv ? XLP9XX_I2C_FIFO_SIZE : msg->len;
+	len = priv->len_recv ? I2C_SMBUS_BLOCK_MAX + 2 : msg->len;
 	priv->client_pec = msg->flags & I2C_CLIENT_PEC;
 
+	/* set FIFO threshold if reading */
+	if (priv->msg_read)
+		xlp9xx_i2c_update_rx_fifo_thres(priv);
+
 	/* set data length to be transferred */
 	val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) |
 	      (len << XLP9XX_I2C_CTRL_MCTLEN_SHIFT);
@@ -378,8 +401,11 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg,
 	}
 
 	/* update msg->len with actual received length */
-	if (msg->flags & I2C_M_RECV_LEN)
+	if (msg->flags & I2C_M_RECV_LEN) {
+		if (!priv->msg_len)
+			return -EPROTO;
 		msg->len = priv->msg_len;
+	}
 	return 0;
 }
 
@@ -447,6 +473,19 @@ static int xlp9xx_i2c_get_frequency(struct platform_device *pdev,
 	return 0;
 }
 
+static int xlp9xx_i2c_smbus_setup(struct xlp9xx_i2c_dev *priv,
+				  struct platform_device *pdev)
+{
+	if (!priv->alert_data.irq)
+		return -EINVAL;
+
+	priv->ara = i2c_setup_smbus_alert(&priv->adapter, &priv->alert_data);
+	if (!priv->ara)
+		return -ENODEV;
+
+	return 0;
+}
+
 static int xlp9xx_i2c_probe(struct platform_device *pdev)
 {
 	struct xlp9xx_i2c_dev *priv;
@@ -467,6 +506,10 @@ static int xlp9xx_i2c_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "invalid irq!\n");
 		return priv->irq;
 	}
+	/* SMBAlert irq */
+	priv->alert_data.irq = platform_get_irq(pdev, 1);
+	if (priv->alert_data.irq <= 0)
+		priv->alert_data.irq = 0;
 
 	xlp9xx_i2c_get_frequency(pdev, priv);
 	xlp9xx_i2c_init(priv);
@@ -493,6 +536,10 @@ static int xlp9xx_i2c_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	err = xlp9xx_i2c_smbus_setup(priv, pdev);
+	if (err)
+		dev_dbg(&pdev->dev, "No active SMBus alert %d\n", err);
+
 	platform_set_drvdata(pdev, priv);
 	dev_dbg(&pdev->dev, "I2C bus:%d added\n", priv->adapter.nr);