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

Pull i2c updates from Wolfram Sang:

 - core supports now bus regulators controlling power for SCL/SDA

 - quite some DT binding conversions to YAML

 - added a seperate DT binding for the optional SMBus Alert feature

 - documentation with examples how to deal with I2C sysfs files

 - some bigger rework for the i801 driver

 - and a few usual driver updates

* 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (42 commits)
  i2c: ali1535: mention that the device should not be disabled
  i2c: mpc: Restore reread of I2C status register
  i2c: core-smbus: Expose PEC calculate function for generic use
  Documentation: i2c: Add doc for I2C sysfs
  i2c: core: Disable client irq on reboot/shutdown
  dt-bindings: i2c: update bindings for MT8195 SoC
  i2c: imx: Fix some checkpatch warnings
  i2c: davinci: Simplify with dev_err_probe()
  i2c: cadence: Simplify with dev_err_probe()
  i2c: xiic: Simplify with dev_err_probe()
  i2c: cadence: Clear HOLD bit before xfer_size register rolls over
  dt-bindings: i2c: ce4100: Replace "ti,pcf8575" by "nxp,pcf8575"
  i2c: i801: Improve i801_setup_hstcfg
  i2c: i801: Use driver name constant instead of function dev_driver_string
  i2c: i801: Simplify initialization of i2c_board_info in i801_probe_optional_slaves
  i2c: i801: Improve status polling
  i2c: cht-wc: Replace of_node by NULL
  i2c: riic: Add RZ/G2L support
  dt-bindings: i2c: renesas,riic: Document RZ/G2L I2C controller
  dt-bindings: i2c: renesas,iic: Convert to json-schema
  ...

16 files changed, 341 insertions, 134 deletions

diff --git a/drivers/i2c/busses/i2c-ali1535.c b/drivers/i2c/busses/i2c-ali1535.c
index fb93152845f4..ee83c4581bce 100644
--- a/drivers/i2c/busses/i2c-ali1535.c
+++ b/drivers/i2c/busses/i2c-ali1535.c
@@ -508,6 +508,11 @@ static void ali1535_remove(struct pci_dev *dev)
 {
 	i2c_del_adapter(&ali1535_adapter);
 	release_region(ali1535_smba, ALI1535_SMB_IOSIZE);
+
+	/*
+	 * do not call pci_disable_device(dev) since it can cause hard hangs on
+	 * some systems during power-off
+	 */
 }
 
 static struct pci_driver ali1535_driver = {
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 724bf30600d6..67e8b97c0c95 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -727,10 +727,14 @@ static void __aspeed_i2c_reg_slave(struct aspeed_i2c_bus *bus, u16 slave_addr)
 {
 	u32 addr_reg_val, func_ctrl_reg_val;
 
-	/* Set slave addr. */
-	addr_reg_val = readl(bus->base + ASPEED_I2C_DEV_ADDR_REG);
-	addr_reg_val &= ~ASPEED_I2CD_DEV_ADDR_MASK;
-	addr_reg_val |= slave_addr & ASPEED_I2CD_DEV_ADDR_MASK;
+	/*
+	 * Set slave addr.  Reserved bits can all safely be written with zeros
+	 * on all of ast2[456]00, so zero everything else to ensure we only
+	 * enable a single slave address (ast2500 has two, ast2600 has three,
+	 * the enable bits for which are also in this register) so that we don't
+	 * end up with additional phantom devices responding on the bus.
+	 */
+	addr_reg_val = slave_addr & ASPEED_I2CD_DEV_ADDR_MASK;
 	writel(addr_reg_val, bus->base + ASPEED_I2C_DEV_ADDR_REG);
 
 	/* Turn on slave mode. */
diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
index 66aafa7d1123..20aa3398e642 100644
--- a/drivers/i2c/busses/i2c-cadence.c
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -578,6 +578,11 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
 {
 	unsigned int ctrl_reg;
 	unsigned int isr_status;
+	unsigned long flags;
+	bool hold_clear = false;
+	bool irq_save = false;
+
+	u32 addr;
 
 	id->p_recv_buf = id->p_msg->buf;
 	id->recv_count = id->p_msg->len;
@@ -618,14 +623,43 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
 		cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_OFFSET);
 	}
 
-	/* Set the slave address in address register - triggers operation */
-	cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
-						CDNS_I2C_ADDR_OFFSET);
-	/* Clear the bus hold flag if bytes to receive is less than FIFO size */
+	/* Determine hold_clear based on number of bytes to receive and hold flag */
 	if (!id->bus_hold_flag &&
-		((id->p_msg->flags & I2C_M_RECV_LEN) != I2C_M_RECV_LEN) &&
-		(id->recv_count <= CDNS_I2C_FIFO_DEPTH))
-			cdns_i2c_clear_bus_hold(id);
+	    ((id->p_msg->flags & I2C_M_RECV_LEN) != I2C_M_RECV_LEN) &&
+	    (id->recv_count <= CDNS_I2C_FIFO_DEPTH)) {
+		if (cdns_i2c_readreg(CDNS_I2C_CR_OFFSET) & CDNS_I2C_CR_HOLD) {
+			hold_clear = true;
+			if (id->quirks & CDNS_I2C_BROKEN_HOLD_BIT)
+				irq_save = true;
+		}
+	}
+
+	addr = id->p_msg->addr;
+	addr &= CDNS_I2C_ADDR_MASK;
+
+	if (hold_clear) {
+		ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET) & ~CDNS_I2C_CR_HOLD;
+		/*
+		 * In case of Xilinx Zynq SOC, clear the HOLD bit before transfer size
+		 * register reaches '0'. This is an IP bug which causes transfer size
+		 * register overflow to 0xFF. To satisfy this timing requirement,
+		 * disable the interrupts on current processor core between register
+		 * writes to slave address register and control register.
+		 */
+		if (irq_save)
+			local_irq_save(flags);
+
+		cdns_i2c_writereg(addr, CDNS_I2C_ADDR_OFFSET);
+		cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
+		/* Read it back to avoid bufferring and make sure write happens */
+		cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+
+		if (irq_save)
+			local_irq_restore(flags);
+	} else {
+		cdns_i2c_writereg(addr, CDNS_I2C_ADDR_OFFSET);
+	}
+
 	cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
 }
 
@@ -1217,11 +1251,10 @@ static int cdns_i2c_probe(struct platform_device *pdev)
 		 "Cadence I2C at %08lx", (unsigned long)r_mem->start);
 
 	id->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(id->clk)) {
-		if (PTR_ERR(id->clk) != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "input clock not found.\n");
-		return PTR_ERR(id->clk);
-	}
+	if (IS_ERR(id->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(id->clk),
+				     "input clock not found.\n");
+
 	ret = clk_prepare_enable(id->clk);
 	if (ret)
 		dev_err(&pdev->dev, "Unable to enable clock.\n");
diff --git a/drivers/i2c/busses/i2c-cht-wc.c b/drivers/i2c/busses/i2c-cht-wc.c
index 08f491ea21ac..1cf68f85b2e1 100644
--- a/drivers/i2c/busses/i2c-cht-wc.c
+++ b/drivers/i2c/busses/i2c-cht-wc.c
@@ -354,8 +354,7 @@ static int cht_wc_i2c_adap_i2c_probe(struct platform_device *pdev)
 		return ret;
 
 	/* Alloc and register client IRQ */
-	adap->irq_domain = irq_domain_add_linear(pdev->dev.of_node, 1,
-						 &irq_domain_simple_ops, NULL);
+	adap->irq_domain = irq_domain_add_linear(NULL, 1, &irq_domain_simple_ops, NULL);
 	if (!adap->irq_domain)
 		return -ENOMEM;
 
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 232a7679b69b..e9d07323c604 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -768,10 +768,7 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 	if (irq <= 0) {
 		if (!irq)
 			irq = -ENXIO;
-		if (irq != -EPROBE_DEFER)
-			dev_err(&pdev->dev,
-				"can't get irq resource ret=%d\n", irq);
-		return irq;
+		return dev_err_probe(&pdev->dev, irq, "can't get irq resource\n");
 	}
 
 	dev = devm_kzalloc(&pdev->dev, sizeof(struct davinci_i2c_dev),
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 04a1e38f2a6f..aa3f60e69230 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -88,6 +88,8 @@
  * See the file Documentation/i2c/busses/i2c-i801.rst for details.
  */
 
+#define DRV_NAME	"i801_smbus"
+
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -103,7 +105,7 @@
 #include <linux/dmi.h>
 #include <linux/slab.h>
 #include <linux/string.h>
-#include <linux/wait.h>
+#include <linux/completion.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/itco_wdt.h>
@@ -131,8 +133,6 @@
 
 /* PCI Address Constants */
 #define SMBBAR		4
-#define SMBPCICTL	0x004
-#define SMBPCISTS	0x006
 #define SMBHSTCFG	0x040
 #define TCOBASE		0x050
 #define TCOCTL		0x054
@@ -141,12 +141,6 @@
 #define SBREG_SMBCTRL		0xc6000c
 #define SBREG_SMBCTRL_DNV	0xcf000c
 
-/* Host status bits for SMBPCISTS */
-#define SMBPCISTS_INTS		BIT(3)
-
-/* Control bits for SMBPCICTL */
-#define SMBPCICTL_INTDIS	BIT(10)
-
 /* Host configuration bits for SMBHSTCFG */
 #define SMBHSTCFG_HST_EN	BIT(0)
 #define SMBHSTCFG_SMB_SMI_EN	BIT(1)
@@ -164,9 +158,6 @@
 #define SMBAUXCTL_CRC		BIT(0)
 #define SMBAUXCTL_E32B		BIT(1)
 
-/* Other settings */
-#define MAX_RETRIES		400
-
 /* I801 command constants */
 #define I801_QUICK		0x00
 #define I801_BYTE		0x04
@@ -270,7 +261,7 @@ struct i801_priv {
 	unsigned int features;
 
 	/* isr processing */
-	wait_queue_head_t waitq;
+	struct completion done;
 	u8 status;
 
 	/* Command state used by isr for byte-by-byte block transactions */
@@ -453,67 +444,53 @@ static int i801_check_post(struct i801_priv *priv, int status)
 /* Wait for BUSY being cleared and either INTR or an error flag being set */
 static int i801_wait_intr(struct i801_priv *priv)
 {
-	int timeout = 0;
-	int status;
+	unsigned long timeout = jiffies + priv->adapter.timeout;
+	int status, busy;
 
-	/* We will always wait for a fraction of a second! */
 	do {
 		usleep_range(250, 500);
 		status = inb_p(SMBHSTSTS(priv));
-	} while (((status & SMBHSTSTS_HOST_BUSY) ||
-		  !(status & (STATUS_ERROR_FLAGS | SMBHSTSTS_INTR))) &&
-		 (timeout++ < MAX_RETRIES));
+		busy = status & SMBHSTSTS_HOST_BUSY;
+		status &= STATUS_ERROR_FLAGS | SMBHSTSTS_INTR;
+		if (!busy && status)
+			return status;
+	} while (time_is_after_eq_jiffies(timeout));
 
-	if (timeout > MAX_RETRIES) {
-		dev_dbg(&priv->pci_dev->dev, "INTR Timeout!\n");
-		return -ETIMEDOUT;
-	}
-	return status & (STATUS_ERROR_FLAGS | SMBHSTSTS_INTR);
+	return -ETIMEDOUT;
 }
 
 /* Wait for either BYTE_DONE or an error flag being set */
 static int i801_wait_byte_done(struct i801_priv *priv)
 {
-	int timeout = 0;
+	unsigned long timeout = jiffies + priv->adapter.timeout;
 	int status;
 
-	/* We will always wait for a fraction of a second! */
 	do {
 		usleep_range(250, 500);
 		status = inb_p(SMBHSTSTS(priv));
-	} while (!(status & (STATUS_ERROR_FLAGS | SMBHSTSTS_BYTE_DONE)) &&
-		 (timeout++ < MAX_RETRIES));
+		if (status & (STATUS_ERROR_FLAGS | SMBHSTSTS_BYTE_DONE))
+			return status & STATUS_ERROR_FLAGS;
+	} while (time_is_after_eq_jiffies(timeout));
 
-	if (timeout > MAX_RETRIES) {
-		dev_dbg(&priv->pci_dev->dev, "BYTE_DONE Timeout!\n");
-		return -ETIMEDOUT;
-	}
-	return status & STATUS_ERROR_FLAGS;
+	return -ETIMEDOUT;
 }
 
 static int i801_transaction(struct i801_priv *priv, int xact)
 {
 	int status;
-	int result;
+	unsigned long result;
 	const struct i2c_adapter *adap = &priv->adapter;
 
-	result = i801_check_pre(priv);
-	if (result < 0)
-		return result;
+	status = i801_check_pre(priv);
+	if (status < 0)
+		return status;
 
 	if (priv->features & FEATURE_IRQ) {
+		reinit_completion(&priv->done);
 		outb_p(xact | SMBHSTCNT_INTREN | SMBHSTCNT_START,
 		       SMBHSTCNT(priv));
-		result = wait_event_timeout(priv->waitq,
-					    (status = priv->status),
-					    adap->timeout);
-		if (!result) {
-			status = -ETIMEDOUT;
-			dev_warn(&priv->pci_dev->dev,
-				 "Timeout waiting for interrupt!\n");
-		}
-		priv->status = 0;
-		return i801_check_post(priv, status);
+		result = wait_for_completion_timeout(&priv->done, adap->timeout);
+		return i801_check_post(priv, result ? priv->status : -ETIMEDOUT);
 	}
 
 	/* the current contents of SMBHSTCNT can be overwritten, since PEC,
@@ -638,7 +615,7 @@ static irqreturn_t i801_host_notify_isr(struct i801_priv *priv)
  *      DEV_ERR - Invalid command, NAK or communication timeout
  *      BUS_ERR - SMI# transaction collision
  *      FAILED - transaction was canceled due to a KILL request
- *    When any of these occur, update ->status and wake up the waitq.
+ *    When any of these occur, update ->status and signal completion.
  *    ->status must be cleared before kicking off the next transaction.
  *
  * 2) For byte-by-byte (I2C read/write) transactions, one BYTE_DONE interrupt
@@ -653,8 +630,8 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
 	u8 status;
 
 	/* Confirm this is our interrupt */
-	pci_read_config_word(priv->pci_dev, SMBPCISTS, &pcists);
-	if (!(pcists & SMBPCISTS_INTS))
+	pci_read_config_word(priv->pci_dev, PCI_STATUS, &pcists);
+	if (!(pcists & PCI_STATUS_INTERRUPT))
 		return IRQ_NONE;
 
 	if (priv->features & FEATURE_HOST_NOTIFY) {
@@ -675,7 +652,7 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
 	if (status) {
 		outb_p(status, SMBHSTSTS(priv));
 		priv->status = status;
-		wake_up(&priv->waitq);
+		complete(&priv->done);
 	}
 
 	return IRQ_HANDLED;
@@ -694,15 +671,15 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv,
 	int i, len;
 	int smbcmd;
 	int status;
-	int result;
+	unsigned long result;
 	const struct i2c_adapter *adap = &priv->adapter;
 
 	if (command == I2C_SMBUS_BLOCK_PROC_CALL)
 		return -EOPNOTSUPP;
 
-	result = i801_check_pre(priv);
-	if (result < 0)
-		return result;
+	status = i801_check_pre(priv);
+	if (status < 0)
+		return status;
 
 	len = data->block[0];
 
@@ -726,17 +703,10 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv,
 		priv->count = 0;
 		priv->data = &data->block[1];
 
+		reinit_completion(&priv->done);
 		outb_p(priv->cmd | SMBHSTCNT_START, SMBHSTCNT(priv));
-		result = wait_event_timeout(priv->waitq,
-					    (status = priv->status),
-					    adap->timeout);
-		if (!result) {
-			status = -ETIMEDOUT;
-			dev_warn(&priv->pci_dev->dev,
-				 "Timeout waiting for interrupt!\n");
-		}
-		priv->status = 0;
-		return i801_check_post(priv, status);
+		result = wait_for_completion_timeout(&priv->done, adap->timeout);
+		return i801_check_post(priv, result ? priv->status : -ETIMEDOUT);
 	}
 
 	for (i = 1; i <= len; i++) {
@@ -1322,11 +1292,11 @@ static void i801_probe_optional_slaves(struct i801_priv *priv)
 		return;
 
 	if (apanel_addr) {
-		struct i2c_board_info info;
+		struct i2c_board_info info = {
+			.addr = apanel_addr,
+			.type = "fujitsu_apanel",
+		};
 
-		memset(&info, 0, sizeof(struct i2c_board_info));
-		info.addr = apanel_addr;
-		strlcpy(info.type, "fujitsu_apanel", I2C_NAME_SIZE);
 		i2c_new_client_device(&priv->adapter, &info);
 	}
 
@@ -1715,19 +1685,17 @@ static inline int i801_acpi_probe(struct i801_priv *priv) { return 0; }
 static inline void i801_acpi_remove(struct i801_priv *priv) { }
 #endif
 
-static unsigned char i801_setup_hstcfg(struct i801_priv *priv)
+static void i801_setup_hstcfg(struct i801_priv *priv)
 {
 	unsigned char hstcfg = priv->original_hstcfg;
 
 	hstcfg &= ~SMBHSTCFG_I2C_EN;	/* SMBus timing */
 	hstcfg |= SMBHSTCFG_HST_EN;
 	pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hstcfg);
-	return hstcfg;
 }
 
 static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
-	unsigned char temp;
 	int err, i;
 	struct i801_priv *priv;
 
@@ -1838,8 +1806,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if (i801_acpi_probe(priv))
 		return -ENODEV;
 
-	err = pcim_iomap_regions(dev, 1 << SMBBAR,
-				 dev_driver_string(&dev->dev));
+	err = pcim_iomap_regions(dev, 1 << SMBBAR, DRV_NAME);
 	if (err) {
 		dev_err(&dev->dev,
 			"Failed to request SMBus region 0x%lx-0x%Lx\n",
@@ -1850,16 +1817,16 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	}
 
 	pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &priv->original_hstcfg);
-	temp = i801_setup_hstcfg(priv);
+	i801_setup_hstcfg(priv);
 	if (!(priv->original_hstcfg & SMBHSTCFG_HST_EN))
 		dev_info(&dev->dev, "Enabling SMBus device\n");
 
-	if (temp & SMBHSTCFG_SMB_SMI_EN) {
+	if (priv->original_hstcfg & SMBHSTCFG_SMB_SMI_EN) {
 		dev_dbg(&dev->dev, "SMBus using interrupt SMI#\n");
 		/* Disable SMBus interrupt feature if SMBus using SMI# */
 		priv->features &= ~FEATURE_IRQ;
 	}
-	if (temp & SMBHSTCFG_SPD_WD)
+	if (priv->original_hstcfg & SMBHSTCFG_SPD_WD)
 		dev_info(&dev->dev, "SPD Write Disable is set\n");
 
 	/* Clear special mode bits */
@@ -1881,24 +1848,23 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		u16 pcictl, pcists;
 
 		/* Complain if an interrupt is already pending */
-		pci_read_config_word(priv->pci_dev, SMBPCISTS, &pcists);
-		if (pcists & SMBPCISTS_INTS)
+		pci_read_config_word(priv->pci_dev, PCI_STATUS, &pcists);
+		if (pcists & PCI_STATUS_INTERRUPT)
 			dev_warn(&dev->dev, "An interrupt is pending!\n");
 
 		/* Check if interrupts have been disabled */
-		pci_read_config_word(priv->pci_dev, SMBPCICTL, &pcictl);
-		if (pcictl & SMBPCICTL_INTDIS) {
+		pci_read_config_word(priv->pci_dev, PCI_COMMAND, &pcictl);
+		if (pcictl & PCI_COMMAND_INTX_DISABLE) {
 			dev_info(&dev->dev, "Interrupts are disabled\n");
 			priv->features &= ~FEATURE_IRQ;
 		}
 	}
 
 	if (priv->features & FEATURE_IRQ) {
-		init_waitqueue_head(&priv->waitq);
+		init_completion(&priv->done);
 
 		err = devm_request_irq(&dev->dev, dev->irq, i801_isr,
-				       IRQF_SHARED,
-				       dev_driver_string(&dev->dev), priv);
+				       IRQF_SHARED, DRV_NAME, priv);
 		if (err) {
 			dev_err(&dev->dev, "Failed to allocate irq %d: %d\n",
 				dev->irq, err);
@@ -1988,7 +1954,7 @@ static int i801_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(i801_pm_ops, i801_suspend, i801_resume);
 
 static struct pci_driver i801_driver = {
-	.name		= "i801_smbus",
+	.name		= DRV_NAME,
 	.id_table	= i801_ids,
 	.probe		= i801_probe,
 	.remove		= i801_remove,
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index dc5ca71906db..d5b5f084a27d 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -170,11 +170,11 @@ enum imx_i2c_type {
 
 struct imx_i2c_hwdata {
 	enum imx_i2c_type	devtype;
-	unsigned		regshift;
+	unsigned int		regshift;
 	struct imx_i2c_clk_pair	*clk_div;
-	unsigned		ndivs;
-	unsigned		i2sr_clr_opcode;
-	unsigned		i2cr_ien_opcode;
+	unsigned int		ndivs;
+	unsigned int		i2sr_clr_opcode;
+	unsigned int		i2cr_ien_opcode;
 };
 
 struct imx_i2c_dma {
@@ -452,8 +452,6 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a
 	unsigned long orig_jiffies = jiffies;
 	unsigned int temp;
 
-	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
-
 	while (1) {
 		temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 
@@ -599,8 +597,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
 	unsigned int temp = 0;
 	int result;
 
-	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
-
 	imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
 	/* Enable I2C controller */
 	imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
@@ -635,7 +631,6 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic)
 
 	if (!i2c_imx->stopped) {
 		/* Stop I2C transaction */
-		dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 		temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 		if (!(temp & I2CR_MSTA))
 			i2c_imx->stopped = 1;
@@ -1167,8 +1162,6 @@ static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
 	bool is_lastmsg = false;
 	struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 
-	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
-
 	/* Start I2C transfer */
 	result = i2c_imx_start(i2c_imx, atomic);
 	if (result) {
@@ -1371,8 +1364,6 @@ static int i2c_imx_probe(struct platform_device *pdev)
 	dma_addr_t phy_addr;
 	const struct imx_i2c_hwdata *match;
 
-	dev_dbg(&pdev->dev, "<%s>\n", __func__);
-
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;
@@ -1395,7 +1386,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
 				platform_get_device_id(pdev)->driver_data;
 
 	/* Setup i2c_imx driver structure */
-	strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
+	strscpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
 	i2c_imx->adapter.owner		= THIS_MODULE;
 	i2c_imx->adapter.algo		= &i2c_imx_algo;
 	i2c_imx->adapter.dev.parent	= &pdev->dev;
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index dcca9c2396db..6d5014ebaab5 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -635,6 +635,8 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
 
 	status = readb(i2c->base + MPC_I2C_SR);
 	if (status & CSR_MIF) {
+		/* Read again to allow register to stabilise */
+		status = readb(i2c->base + MPC_I2C_SR);
 		writeb(0, i2c->base + MPC_I2C_SR);
 		mpc_i2c_do_intr(i2c, status);
 		return IRQ_HANDLED;
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 4e9fb6b44436..4ca716e09149 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -1225,6 +1225,13 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 	i2c->adap.quirks = i2c->dev_comp->quirks;
 	i2c->adap.timeout = 2 * HZ;
 	i2c->adap.retries = 1;
+	i2c->adap.bus_regulator = devm_regulator_get_optional(&pdev->dev, "vbus");
+	if (IS_ERR(i2c->adap.bus_regulator)) {
+		if (PTR_ERR(i2c->adap.bus_regulator) == -ENODEV)
+			i2c->adap.bus_regulator = NULL;
+		else
+			return PTR_ERR(i2c->adap.bus_regulator);
+	}
 
 	ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c);
 	if (ret)
@@ -1286,7 +1293,7 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 
 	ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq,
 			       IRQF_NO_SUSPEND | IRQF_TRIGGER_NONE,
-			       I2C_DRV_NAME, i2c);
+			       dev_name(&pdev->dev), i2c);
 	if (ret < 0) {
 		dev_err(&pdev->dev,
 			"Request I2C IRQ %d fail\n", irq);
diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
index c63d5545fc2a..c1de8eb66169 100644
--- a/drivers/i2c/busses/i2c-qcom-cci.c
+++ b/drivers/i2c/busses/i2c-qcom-cci.c
@@ -769,6 +769,7 @@ static const struct of_device_id cci_dt_match[] = {
 	{ .compatible = "qcom,msm8916-cci", .data = &cci_v1_data},
 	{ .compatible = "qcom,msm8996-cci", .data = &cci_v2_data},
 	{ .compatible = "qcom,sdm845-cci", .data = &cci_v2_data},
+	{ .compatible = "qcom,sm8250-cci", .data = &cci_v2_data},
 	{}
 };
 MODULE_DEVICE_TABLE(of, cci_dt_match);
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 327c092a4130..bff9913c37b8 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -1013,7 +1013,6 @@ static const struct of_device_id rcar_i2c_dt_ids[] = {
 	{ .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
 	{ .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 },
 	{ .compatible = "renesas,i2c-r8a7796", .data = (void *)I2C_RCAR_GEN3 },
-	{ .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 },	/* Deprecated */
 	{ .compatible = "renesas,rcar-gen1-i2c", .data = (void *)I2C_RCAR_GEN1 },
 	{ .compatible = "renesas,rcar-gen2-i2c", .data = (void *)I2C_RCAR_GEN2 },
 	{ .compatible = "renesas,rcar-gen3-i2c", .data = (void *)I2C_RCAR_GEN3 },
diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index 4eccc0f69861..78b84445ee6a 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -42,8 +42,10 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 
 #define RIIC_ICCR1	0x00
 #define RIIC_ICCR2	0x04
@@ -86,6 +88,11 @@
 
 #define RIIC_INIT_MSG	-1
 
+enum riic_type {
+	RIIC_RZ_A,
+	RIIC_RZ_G2L,
+};
+
 struct riic_dev {
 	void __iomem *base;
 	u8 *buf;
@@ -395,7 +402,9 @@ static int riic_i2c_probe(struct platform_device *pdev)
 	struct i2c_adapter *adap;
 	struct resource *res;
 	struct i2c_timings i2c_t;
+	struct reset_control *rstc;
 	int i, ret;
+	enum riic_type type;
 
 	riic = devm_kzalloc(&pdev->dev, sizeof(*riic), GFP_KERNEL);
 	if (!riic)
@@ -412,6 +421,17 @@ static int riic_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(riic->clk);
 	}
 
+	type = (enum riic_type)of_device_get_match_data(&pdev->dev);
+	if (type == RIIC_RZ_G2L) {
+		rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+		if (IS_ERR(rstc)) {
+			dev_err(&pdev->dev, "Error: missing reset ctrl\n");
+			return PTR_ERR(rstc);
+		}
+
+		reset_control_deassert(rstc);
+	}
+
 	for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {
 		res = platform_get_resource(pdev, IORESOURCE_IRQ, riic_irqs[i].res_num);
 		if (!res)
@@ -472,7 +492,8 @@ static int riic_i2c_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id riic_i2c_dt_ids[] = {
-	{ .compatible = "renesas,riic-rz" },
+	{ .compatible = "renesas,riic-r9a07g044", .data = (void *)RIIC_RZ_G2L },
+	{ .compatible = "renesas,riic-rz", .data = (void *)RIIC_RZ_A },
 	{ /* Sentinel */ },
 };
 
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 0138317ea600..b9b19a2a2ffa 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -51,6 +51,7 @@
 
 /* STM32F7 I2C control 1 */
 #define STM32F7_I2C_CR1_PECEN			BIT(23)
+#define STM32F7_I2C_CR1_ALERTEN			BIT(22)
 #define STM32F7_I2C_CR1_SMBHEN			BIT(20)
 #define STM32F7_I2C_CR1_WUPEN			BIT(18)
 #define STM32F7_I2C_CR1_SBC			BIT(16)
@@ -125,6 +126,7 @@
 				(((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17)
 #define STM32F7_I2C_ISR_DIR			BIT(16)
 #define STM32F7_I2C_ISR_BUSY			BIT(15)
+#define STM32F7_I2C_ISR_ALERT			BIT(13)
 #define STM32F7_I2C_ISR_PECERR			BIT(11)
 #define STM32F7_I2C_ISR_ARLO			BIT(9)
 #define STM32F7_I2C_ISR_BERR			BIT(8)
@@ -138,6 +140,7 @@
 #define STM32F7_I2C_ISR_TXE			BIT(0)
 
 /* STM32F7 I2C Interrupt Clear */
+#define STM32F7_I2C_ICR_ALERTCF			BIT(13)
 #define STM32F7_I2C_ICR_PECCF			BIT(11)
 #define STM32F7_I2C_ICR_ARLOCF			BIT(9)
 #define STM32F7_I2C_ICR_BERRCF			BIT(8)
@@ -279,6 +282,17 @@ struct stm32f7_i2c_msg {
 };
 
 /**
+ * struct stm32f7_i2c_alert - SMBus alert specific data
+ * @setup: platform data for the smbus_alert i2c client
+ * @ara: I2C slave device used to respond to the SMBus Alert with Alert
+ * Response Address
+ */
+struct stm32f7_i2c_alert {
+	struct i2c_smbus_alert_setup setup;
+	struct i2c_client *ara;
+};
+
+/**
  * struct stm32f7_i2c_dev - private data of the controller
  * @adap: I2C adapter for this controller
  * @dev: device for this controller
@@ -310,6 +324,7 @@ struct stm32f7_i2c_msg {
  * @analog_filter: boolean to indicate enabling of the analog filter
  * @dnf_dt: value of digital filter requested via dt
  * @dnf: value of digital filter to apply
+ * @alert: SMBus alert specific data
  */
 struct stm32f7_i2c_dev {
 	struct i2c_adapter adap;
@@ -341,6 +356,7 @@ struct stm32f7_i2c_dev {
 	bool analog_filter;
 	u32 dnf_dt;
 	u32 dnf;
+	struct stm32f7_i2c_alert *alert;
 };
 
 /*
@@ -1624,6 +1640,13 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
 		f7_msg->result = -EINVAL;
 	}
 
+	if (status & STM32F7_I2C_ISR_ALERT) {
+		dev_dbg(dev, "<%s>: SMBus alert received\n", __func__);
+		writel_relaxed(STM32F7_I2C_ICR_ALERTCF, base + STM32F7_I2C_ICR);
+		i2c_handle_smbus_alert(i2c_dev->alert->ara);
+		return IRQ_HANDLED;
+	}
+
 	if (!i2c_dev->slave_running) {
 		u32 mask;
 		/* Disable interrupts */
@@ -1990,6 +2013,42 @@ static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
 	}
 }
 
+static int stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct stm32f7_i2c_alert *alert;
+	struct i2c_adapter *adap = &i2c_dev->adap;
+	struct device *dev = i2c_dev->dev;
+	void __iomem *base = i2c_dev->base;
+
+	alert = devm_kzalloc(dev, sizeof(*alert), GFP_KERNEL);
+	if (!alert)
+		return -ENOMEM;
+
+	alert->ara = i2c_new_smbus_alert_device(adap, &alert->setup);
+	if (IS_ERR(alert->ara))
+		return PTR_ERR(alert->ara);
+
+	i2c_dev->alert = alert;
+
+	/* Enable SMBus Alert */
+	stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_ALERTEN);
+
+	return 0;
+}
+
+static void stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct stm32f7_i2c_alert *alert = i2c_dev->alert;
+	void __iomem *base = i2c_dev->base;
+
+	if (alert) {
+		/* Disable SMBus Alert */
+		stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
+				     STM32F7_I2C_CR1_ALERTEN);
+		i2c_unregister_device(alert->ara);
+	}
+}
+
 static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
 {
 	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
@@ -2173,6 +2232,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 		}
 	}
 
+	if (of_property_read_bool(pdev->dev.of_node, "smbus-alert")) {
+		ret = stm32f7_i2c_enable_smbus_alert(i2c_dev);
+		if (ret) {
+			dev_err(i2c_dev->dev,
+				"failed to enable SMBus alert protocol (%d)\n",
+				ret);
+			goto i2c_disable_smbus_host;
+		}
+	}
+
 	dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
 
 	pm_runtime_mark_last_busy(i2c_dev->dev);
@@ -2180,6 +2249,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
 
 	return 0;
 
+i2c_disable_smbus_host:
+	stm32f7_i2c_disable_smbus_host(i2c_dev);
+
 i2c_adapter_remove:
 	i2c_del_adapter(adap);
 
@@ -2214,6 +2286,7 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
 {
 	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
 
+	stm32f7_i2c_disable_smbus_alert(i2c_dev);
 	stm32f7_i2c_disable_smbus_host(i2c_dev);
 
 	i2c_del_adapter(&i2c_dev->adap);
diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index 2a8568b97c14..bb93db98404e 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -798,11 +798,10 @@ static int xiic_i2c_probe(struct platform_device *pdev)
 	init_waitqueue_head(&i2c->wait);
 
 	i2c->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(i2c->clk)) {
-		if (PTR_ERR(i2c->clk) != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "input clock not found.\n");
-		return PTR_ERR(i2c->clk);
-	}
+	if (IS_ERR(i2c->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(i2c->clk),
+				     "input clock not found.\n");
+
 	ret = clk_prepare_enable(i2c->clk);
 	if (ret) {
 		dev_err(&pdev->dev, "Unable to enable clock.\n");
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 5a97e4a02fa2..84f12bf90644 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -24,6 +24,7 @@
 #include <linux/i2c-smbus.h>
 #include <linux/idr.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/irqflags.h>
 #include <linux/jump_label.h>
 #include <linux/kernel.h>
@@ -399,7 +400,8 @@ static int i2c_gpio_init_recovery(struct i2c_adapter *adap)
 static int i2c_init_recovery(struct i2c_adapter *adap)
 {
 	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
-	char *err_str, *err_level = KERN_ERR;
+	bool is_error_level = true;
+	char *err_str;
 
 	if (!bri)
 		return 0;
@@ -409,7 +411,7 @@ static int i2c_init_recovery(struct i2c_adapter *adap)
 
 	if (!bri->recover_bus) {
 		err_str = "no suitable method provided";
-		err_level = KERN_DEBUG;
+		is_error_level = false;
 		goto err;
 	}
 
@@ -436,7 +438,10 @@ static int i2c_init_recovery(struct i2c_adapter *adap)
 
 	return 0;
  err:
-	dev_printk(err_level, &adap->dev, "Not using recovery: %s\n", err_str);
+	if (is_error_level)
+		dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
+	else
+		dev_dbg(&adap->dev, "Not using recovery: %s\n", err_str);
 	adap->bus_recovery_info = NULL;
 
 	return -EINVAL;
@@ -461,12 +466,14 @@ static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
 static int i2c_device_probe(struct device *dev)
 {
 	struct i2c_client	*client = i2c_verify_client(dev);
+	struct i2c_adapter	*adap;
 	struct i2c_driver	*driver;
 	int status;
 
 	if (!client)
 		return 0;
 
+	adap = client->adapter;
 	client->irq = client->init_irq;
 
 	if (!client->irq) {
@@ -532,6 +539,14 @@ static int i2c_device_probe(struct device *dev)
 
 	dev_dbg(dev, "probe\n");
 
+	if (adap->bus_regulator) {
+		status = regulator_enable(adap->bus_regulator);
+		if (status < 0) {
+			dev_err(&adap->dev, "Failed to enable bus regulator\n");
+			goto err_clear_wakeup_irq;
+		}
+	}
+
 	status = of_clk_set_defaults(dev->of_node, false);
 	if (status < 0)
 		goto err_clear_wakeup_irq;
@@ -589,8 +604,10 @@ put_sync_adapter:
 static int i2c_device_remove(struct device *dev)
 {
 	struct i2c_client	*client = to_i2c_client(dev);
+	struct i2c_adapter      *adap;
 	struct i2c_driver	*driver;
 
+	adap = client->adapter;
 	driver = to_i2c_driver(dev->driver);
 	if (driver->remove) {
 		int status;
@@ -605,6 +622,8 @@ static int i2c_device_remove(struct device *dev)
 	devres_release_group(&client->dev, client->devres_group_id);
 
 	dev_pm_domain_detach(&client->dev, true);
+	if (!pm_runtime_status_suspended(&client->dev) && adap->bus_regulator)
+		regulator_disable(adap->bus_regulator);
 
 	dev_pm_clear_wake_irq(&client->dev);
 	device_init_wakeup(&client->dev, false);
@@ -617,6 +636,86 @@ static int i2c_device_remove(struct device *dev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int i2c_resume_early(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client)
+		return 0;
+
+	if (pm_runtime_status_suspended(&client->dev) &&
+		client->adapter->bus_regulator) {
+		err = regulator_enable(client->adapter->bus_regulator);
+		if (err)
+			return err;
+	}
+
+	return pm_generic_resume_early(&client->dev);
+}
+
+static int i2c_suspend_late(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client)
+		return 0;
+
+	err = pm_generic_suspend_late(&client->dev);
+	if (err)
+		return err;
+
+	if (!pm_runtime_status_suspended(&client->dev) &&
+		client->adapter->bus_regulator)
+		return regulator_disable(client->adapter->bus_regulator);
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int i2c_runtime_resume(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client)
+		return 0;
+
+	if (client->adapter->bus_regulator) {
+		err = regulator_enable(client->adapter->bus_regulator);
+		if (err)
+			return err;
+	}
+
+	return pm_generic_runtime_resume(&client->dev);
+}
+
+static int i2c_runtime_suspend(struct device *dev)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	int err;
+
+	if (!client)
+		return 0;
+
+	err = pm_generic_runtime_suspend(&client->dev);
+	if (err)
+		return err;
+
+	if (client->adapter->bus_regulator)
+		return regulator_disable(client->adapter->bus_regulator);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops i2c_device_pm = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(i2c_suspend_late, i2c_resume_early)
+	SET_RUNTIME_PM_OPS(i2c_runtime_suspend, i2c_runtime_resume, NULL)
+};
+
 static void i2c_device_shutdown(struct device *dev)
 {
 	struct i2c_client *client = i2c_verify_client(dev);
@@ -627,6 +726,8 @@ static void i2c_device_shutdown(struct device *dev)
 	driver = to_i2c_driver(dev->driver);
 	if (driver->shutdown)
 		driver->shutdown(client);
+	else if (client->irq > 0)
+		disable_irq(client->irq);
 }
 
 static void i2c_client_dev_release(struct device *dev)
@@ -674,6 +775,7 @@ struct bus_type i2c_bus_type = {
 	.probe		= i2c_device_probe,
 	.remove		= i2c_device_remove,
 	.shutdown	= i2c_device_shutdown,
+	.pm		= &i2c_device_pm,
 };
 EXPORT_SYMBOL_GPL(i2c_bus_type);
 
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index d2d32c0fd8c3..e5b2d1465e7e 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -37,8 +37,15 @@ static u8 crc8(u16 data)
 	return (u8)(data >> 8);
 }
 
-/* Incremental CRC8 over count bytes in the array pointed to by p */
-static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
+/**
+ * i2c_smbus_pec - Incremental CRC8 over the given input data array
+ * @crc: previous return crc8 value
+ * @p: pointer to data buffer.
+ * @count: number of bytes in data buffer.
+ *
+ * Incremental CRC8 over count bytes in the array pointed to by p
+ */
+u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
 {
 	int i;
 
@@ -46,6 +53,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
 		crc = crc8((crc ^ p[i]) << 8);
 	return crc;
 }
+EXPORT_SYMBOL(i2c_smbus_pec);
 
 /* Assume a 7-bit address, which is reasonable for SMBus */
 static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)