Merge branch 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - if a host can be a client, too, the I2C core can now use it to
   emulate SMBus HostNotify support (STM32 and R-Car added this so far)

 - also for client mode, a testunit has been added. It can create rare
   situations on the bus, so host controllers can be tested

 - a binding has been added to mark the bus as "single-master". This
   allows for better timeout detections

 - new driver for Mellanox Bluefield

 - massive refactoring of the Tegra driver

 - EEPROMs recognized by the at24 driver can now have custom names

 - rest is driver updates

* 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (80 commits)
  Documentation: i2c: add testunit docs to index
  i2c: tegra: Improve driver module description
  i2c: tegra: Clean up whitespaces, newlines and indentation
  i2c: tegra: Clean up and improve comments
  i2c: tegra: Clean up printk messages
  i2c: tegra: Clean up variable names
  i2c: tegra: Improve formatting of variables
  i2c: tegra: Check errors for both positive and negative values
  i2c: tegra: Factor out hardware initialization into separate function
  i2c: tegra: Factor out register polling into separate function
  i2c: tegra: Factor out packet header setup from tegra_i2c_xfer_msg()
  i2c: tegra: Factor out error recovery from tegra_i2c_xfer_msg()
  i2c: tegra: Rename wait/poll functions
  i2c: tegra: Remove "dma" variable from tegra_i2c_xfer_msg()
  i2c: tegra: Remove redundant check in tegra_i2c_issue_bus_clear()
  i2c: tegra: Remove likely/unlikely from the code
  i2c: tegra: Remove outdated barrier()
  i2c: tegra: Clean up variable types
  i2c: tegra: Reorder location of functions in the code
  i2c: tegra: Clean up probe function
  ...

1 files changed, 41 insertions, 24 deletions

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index c7c543483b08..217def2d7cb4 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -19,7 +19,9 @@
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
@@ -105,10 +107,11 @@
 #define ID_ARBLOST	(1 << 3)
 #define ID_NACK		(1 << 4)
 /* persistent flags */
+#define ID_P_HOST_NOTIFY	BIT(28)
 #define ID_P_REP_AFTER_RD	BIT(29)
 #define ID_P_NO_RXDMA		BIT(30) /* HW forbids RXDMA sometimes */
 #define ID_P_PM_BLOCKED		BIT(31)
-#define ID_P_MASK		GENMASK(31, 29)
+#define ID_P_MASK		GENMASK(31, 28)
 
 enum rcar_i2c_type {
 	I2C_RCAR_GEN1,
@@ -140,14 +143,13 @@ struct rcar_i2c_priv {
 
 	struct reset_control *rstc;
 	int irq;
+
+	struct i2c_client *host_notify_client;
 };
 
 #define rcar_i2c_priv_to_dev(p)		((p)->adap.dev.parent)
 #define rcar_i2c_is_recv(p)		((p)->msg->flags & I2C_M_RD)
 
-#define LOOP_TIMEOUT	1024
-
-
 static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
 {
 	writel(val, priv->io + reg);
@@ -221,18 +223,18 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
 
 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 {
-	int i;
+	int ret;
+	u32 val;
 
-	for (i = 0; i < LOOP_TIMEOUT; i++) {
-		/* make sure that bus is not busy */
-		if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
-			return 0;
-		udelay(1);
+	ret = readl_poll_timeout(priv->io + ICMCR, val, !(val & FSDA), 10,
+				 priv->adap.timeout);
+	if (ret) {
+		/* Waiting did not help, try to recover */
+		priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
+		ret = i2c_recover_bus(&priv->adap);
 	}
 
-	/* Waiting did not help, try to recover */
-	priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
-	return i2c_recover_bus(&priv->adap);
+	return ret;
 }
 
 static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv)
@@ -760,20 +762,14 @@ static void rcar_i2c_release_dma(struct rcar_i2c_priv *priv)
 /* I2C is a special case, we need to poll the status of a reset */
 static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv)
 {
-	int i, ret;
+	int ret;
 
 	ret = reset_control_reset(priv->rstc);
 	if (ret)
 		return ret;
 
-	for (i = 0; i < LOOP_TIMEOUT; i++) {
-		ret = reset_control_status(priv->rstc);
-		if (ret == 0)
-			return 0;
-		udelay(1);
-	}
-
-	return -ETIMEDOUT;
+	return read_poll_timeout_atomic(reset_control_status, ret, ret == 0, 1,
+					100, false, priv->rstc);
 }
 
 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
@@ -884,14 +880,21 @@ static int rcar_unreg_slave(struct i2c_client *slave)
 
 static u32 rcar_i2c_func(struct i2c_adapter *adap)
 {
+	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
 	/*
 	 * This HW can't do:
 	 * I2C_SMBUS_QUICK (setting FSB during START didn't work)
 	 * I2C_M_NOSTART (automatically sends address after START)
 	 * I2C_M_IGNORE_NAK (automatically sends STOP after NAK)
 	 */
-	return I2C_FUNC_I2C | I2C_FUNC_SLAVE |
-		(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+	u32 func = I2C_FUNC_I2C | I2C_FUNC_SLAVE |
+		   (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+
+	if (priv->flags & ID_P_HOST_NOTIFY)
+		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
+
+	return func;
 }
 
 static const struct i2c_algorithm rcar_i2c_algo = {
@@ -991,6 +994,8 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	else
 		pm_runtime_put(dev);
 
+	if (of_property_read_bool(dev->of_node, "smbus"))
+		priv->flags |= ID_P_HOST_NOTIFY;
 
 	priv->irq = platform_get_irq(pdev, 0);
 	ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, dev_name(dev), priv);
@@ -1005,10 +1010,20 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto out_pm_disable;
 
+	if (priv->flags & ID_P_HOST_NOTIFY) {
+		priv->host_notify_client = i2c_new_slave_host_notify_device(adap);
+		if (IS_ERR(priv->host_notify_client)) {
+			ret = PTR_ERR(priv->host_notify_client);
+			goto out_del_device;
+		}
+	}
+
 	dev_info(dev, "probed\n");
 
 	return 0;
 
+ out_del_device:
+	i2c_del_adapter(&priv->adap);
  out_pm_put:
 	pm_runtime_put(dev);
  out_pm_disable:
@@ -1021,6 +1036,8 @@ static int rcar_i2c_remove(struct platform_device *pdev)
 	struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
 	struct device *dev = &pdev->dev;
 
+	if (priv->host_notify_client)
+		i2c_free_slave_host_notify_device(priv->host_notify_client);
 	i2c_del_adapter(&priv->adap);
 	rcar_i2c_release_dma(priv);
 	if (priv->flags & ID_P_PM_BLOCKED)