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

Pull more i2c updates from Wolfram Sang:
 "Mostly bugfixes, small but wanted cleanups, and Paul's init.h removal
  applied"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: rcar: fix NACK error code
  i2c: update i2c_algorithm documentation
  i2c: rcar: use devm_clk_get to ensure clock is properly ref-counted
  i2c: rcar: do not print error if device nacks transfer
  i2c: rely on driver core when sanitizing devices
  i2c: delete non-required instances of include <linux/init.h>
  i2c: acorn: is tristate and should use module.h
  i2c: piix4: Standardize log messages
  i2c: piix4: Use different message for AMD Auxiliary SMBus Controller
  i2c: piix4: Add support for AMD ML and CZ SMBus changes

Documentation/i2c/busses/i2c-piix4

@@ -13,7 +13,7 @@ Supported adapters:
   * AMD SP5100 (SB700 derivative found on some server mainboards)
     Datasheet: Publicly available at the AMD website
     http://support.amd.com/us/Embedded_TechDocs/44413.pdf
-  * AMD Hudson-2, CZ
+  * AMD Hudson-2, ML, CZ
     Datasheet: Not publicly available
   * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge
     Datasheet: Publicly available at the SMSC website http://www.smsc.com

drivers/i2c/algos/i2c-algo-bit.c

@@ -25,7 +25,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/delay.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/i2c.h>

drivers/i2c/algos/i2c-algo-pca.c

@@ -24,7 +24,6 @@
 #include <linux/moduleparam.h>
 #include <linux/delay.h>
 #include <linux/jiffies.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-pca.h>

drivers/i2c/algos/i2c-algo-pcf.c

@@ -30,7 +30,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/delay.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-pcf.h>

drivers/i2c/busses/Kconfig

@@ -152,6 +152,7 @@ config I2C_PIIX4
 	    ATI SB700/SP5100
 	    ATI SB800
 	    AMD Hudson-2
+	    AMD ML
 	    AMD CZ
 	    Serverworks OSB4
 	    Serverworks CSB5

drivers/i2c/busses/i2c-acorn.c

@@ -12,7 +12,7 @@
  *  On Acorn machines, the following i2c devices are on the bus:
  *	- PCF8583 real time clock & static RAM
  */
-#include <linux/init.h>
+#include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 #include <linux/io.h>

drivers/i2c/busses/i2c-ali1535.c

@@ -58,7 +58,6 @@
 #include <linux/delay.h>
 #include <linux/ioport.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 

drivers/i2c/busses/i2c-ali1563.c

@@ -20,7 +20,6 @@
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/pci.h>
-#include <linux/init.h>
 #include <linux/acpi.h>
 
 #define ALI1563_MAX_TIMEOUT	500

drivers/i2c/busses/i2c-ali15x3.c

@@ -65,7 +65,6 @@
 #include <linux/ioport.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 

drivers/i2c/busses/i2c-amd756.c

@@ -41,7 +41,6 @@
 #include <linux/stddef.h>
 #include <linux/ioport.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 

drivers/i2c/busses/i2c-amd8111.c

@@ -13,7 +13,6 @@
 #include <linux/kernel.h>
 #include <linux/stddef.h>
 #include <linux/ioport.h>
-#include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/acpi.h>

drivers/i2c/busses/i2c-au1550.c

@@ -31,7 +31,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>

drivers/i2c/busses/i2c-cbus-gpio.c

@@ -19,7 +19,6 @@
 #include <linux/io.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
-#include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/errno.h>

drivers/i2c/busses/i2c-cpm.c

@@ -33,7 +33,6 @@
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
-#include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/errno.h>
 #include <linux/stddef.h>

drivers/i2c/busses/i2c-eg20t.c

@@ -18,7 +18,6 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
 #include <linux/fs.h>

drivers/i2c/busses/i2c-exynos5.c

@@ -12,7 +12,6 @@
 #include <linux/module.h>
 
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/time.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>

drivers/i2c/busses/i2c-highlander.c

@@ -12,7 +12,6 @@
  * of this archive for more details.
  */
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/platform_device.h>

drivers/i2c/busses/i2c-hydra.c

@@ -27,7 +27,6 @@
 #include <linux/types.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
-#include <linux/init.h>
 #include <linux/io.h>
 #include <asm/hydra.h>
 

drivers/i2c/busses/i2c-ibm_iic.c

@@ -36,7 +36,6 @@
 #include <linux/ioport.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
-#include <linux/init.h>
 #include <linux/interrupt.h>
 #include <asm/irq.h>
 #include <linux/io.h>

drivers/i2c/busses/i2c-iop3xx.c

@@ -34,7 +34,6 @@
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>

drivers/i2c/busses/i2c-isch.c

@@ -33,7 +33,6 @@
 #include <linux/stddef.h>
 #include <linux/ioport.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/io.h>
 #include <linux/acpi.h>
 

drivers/i2c/busses/i2c-ismt.c

@@ -62,7 +62,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/kernel.h>
 #include <linux/stddef.h>

drivers/i2c/busses/i2c-mpc.c

@@ -16,7 +16,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/sched.h>
-#include <linux/init.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>

drivers/i2c/busses/i2c-nforce2.c

@@ -51,7 +51,6 @@
 #include <linux/kernel.h>
 #include <linux/stddef.h>
 #include <linux/ioport.h>
-#include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/dmi.h>

drivers/i2c/busses/i2c-ocores.c

@@ -15,7 +15,6 @@
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>

drivers/i2c/busses/i2c-octeon.c

@@ -18,7 +18,6 @@
 #include <linux/delay.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
-#include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/io.h>
 #include <linux/of.h>

drivers/i2c/busses/i2c-pca-platform.c

@@ -12,7 +12,6 @@
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/jiffies.h>

drivers/i2c/busses/i2c-piix4.c

@@ -22,7 +22,7 @@
 	Intel PIIX4, 440MX
 	Serverworks OSB4, CSB5, CSB6, HT-1000, HT-1100
 	ATI IXP200, IXP300, IXP400, SB600, SB700/SP5100, SB800
-	AMD Hudson-2, CZ
+	AMD Hudson-2, ML, CZ
 	SMSC Victory66
 
    Note: we assume there can only be one device, with one or more
@@ -38,7 +38,6 @@
 #include <linux/ioport.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
-#include <linux/init.h>
 #include <linux/dmi.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
@@ -208,16 +207,16 @@ static int piix4_setup(struct pci_dev *PIIX4_dev,
 				   "WARNING: SMBus interface has been FORCEFULLY ENABLED!\n");
 		} else {
 			dev_err(&PIIX4_dev->dev,
-				"Host SMBus controller not enabled!\n");
+				"SMBus Host Controller not enabled!\n");
 			release_region(piix4_smba, SMBIOSIZE);
 			return -ENODEV;
 		}
 	}
 
 	if (((temp & 0x0E) == 8) || ((temp & 0x0E) == 2))
-		dev_dbg(&PIIX4_dev->dev, "Using Interrupt 9 for SMBus.\n");
+		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
 	else if ((temp & 0x0E) == 0)
-		dev_dbg(&PIIX4_dev->dev, "Using Interrupt SMI# for SMBus.\n");
+		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
 	else
 		dev_err(&PIIX4_dev->dev, "Illegal Interrupt configuration "
 			"(or code out of date)!\n");
@@ -235,7 +234,8 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 {
 	unsigned short piix4_smba;
 	unsigned short smba_idx = 0xcd6;
-	u8 smba_en_lo, smba_en_hi, i2ccfg, i2ccfg_offset = 0x10, smb_en;
+	u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status;
+	u8 i2ccfg, i2ccfg_offset = 0x10;
 
 	/* SB800 and later SMBus does not support forcing address */
 	if (force || force_addr) {
@@ -245,7 +245,15 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 	}
 
 	/* Determine the address of the SMBus areas */
-	smb_en = (aux) ? 0x28 : 0x2c;
+	if ((PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
+	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
+	     PIIX4_dev->revision >= 0x41) ||
+	    (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
+	     PIIX4_dev->device == 0x790b &&
+	     PIIX4_dev->revision >= 0x49))
+		smb_en = 0x00;
+	else
+		smb_en = (aux) ? 0x28 : 0x2c;
 
 	if (!request_region(smba_idx, 2, "smba_idx")) {
 		dev_err(&PIIX4_dev->dev, "SMBus base address index region "
@@ -258,13 +266,22 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 	smba_en_hi = inb_p(smba_idx + 1);
 	release_region(smba_idx, 2);
 
-	if ((smba_en_lo & 1) == 0) {
+	if (!smb_en) {
+		smb_en_status = smba_en_lo & 0x10;
+		piix4_smba = smba_en_hi << 8;
+		if (aux)
+			piix4_smba |= 0x20;
+	} else {
+		smb_en_status = smba_en_lo & 0x01;
+		piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
+	}
+
+	if (!smb_en_status) {
 		dev_err(&PIIX4_dev->dev,
-			"Host SMBus controller not enabled!\n");
+			"SMBus Host Controller not enabled!\n");
 		return -ENODEV;
 	}
 
-	piix4_smba = ((smba_en_hi << 8) | smba_en_lo) & 0xffe0;
 	if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
 		return -ENODEV;
 
@@ -277,7 +294,8 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 	/* Aux SMBus does not support IRQ information */
 	if (aux) {
 		dev_info(&PIIX4_dev->dev,
-			 "SMBus Host Controller at 0x%x\n", piix4_smba);
+			 "Auxiliary SMBus Host Controller at 0x%x\n",
+			 piix4_smba);
 		return piix4_smba;
 	}
 
@@ -292,9 +310,9 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 	release_region(piix4_smba + i2ccfg_offset, 1);
 
 	if (i2ccfg & 1)
-		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus.\n");
+		dev_dbg(&PIIX4_dev->dev, "Using IRQ for SMBus\n");
 	else
-		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus.\n");
+		dev_dbg(&PIIX4_dev->dev, "Using SMI# for SMBus\n");
 
 	dev_info(&PIIX4_dev->dev,
 		 "SMBus Host Controller at 0x%x, revision %d\n",

drivers/i2c/busses/i2c-pmcmsp.c

@@ -26,7 +26,6 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>

drivers/i2c/busses/i2c-powermac.c

@@ -24,7 +24,6 @@
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/of_irq.h>

drivers/i2c/busses/i2c-puv3.c

@@ -17,7 +17,6 @@
 #include <linux/types.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/clk.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>

drivers/i2c/busses/i2c-rcar.c

@@ -26,7 +26,6 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/err.h>
-#include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/i2c.h>
@@ -111,6 +110,7 @@ struct rcar_i2c_priv {
 	void __iomem *io;
 	struct i2c_adapter adap;
 	struct i2c_msg	*msg;
+	struct clk *clk;
 
 	spinlock_t lock;
 	wait_queue_head_t wait;
@@ -227,18 +227,12 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
 				    u32 bus_speed,
 				    struct device *dev)
 {
-	struct clk *clkp = clk_get(dev, NULL);
 	u32 scgd, cdf;
 	u32 round, ick;
 	u32 scl;
 	u32 cdf_width;
 	unsigned long rate;
 
-	if (IS_ERR(clkp)) {
-		dev_err(dev, "couldn't get clock\n");
-		return PTR_ERR(clkp);
-	}
-
 	switch (priv->devtype) {
 	case I2C_RCAR_GEN1:
 		cdf_width = 2;
@@ -266,7 +260,7 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
 	 * clkp : peripheral_clk
 	 * F[]  : integer up-valuation
 	 */
-	rate = clk_get_rate(clkp);
+	rate = clk_get_rate(priv->clk);
 	cdf = rate / 20000000;
 	if (cdf >= 1 << cdf_width) {
 		dev_err(dev, "Input clock %lu too high\n", rate);
@@ -308,7 +302,7 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
 
 scgd_find:
 	dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n",
-		scl, bus_speed, clk_get_rate(clkp), round, cdf, scgd);
+		scl, bus_speed, clk_get_rate(priv->clk), round, cdf, scgd);
 
 	/*
 	 * keep icccr value
@@ -604,7 +598,7 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 		 * error handling
 		 */
 		if (rcar_i2c_flags_has(priv, ID_NACK)) {
-			ret = -EREMOTEIO;
+			ret = -ENXIO;
 			break;
 		}
 
@@ -623,7 +617,7 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 
 	pm_runtime_put(dev);
 
-	if (ret < 0)
+	if (ret < 0 && ret != -ENXIO)
 		dev_err(dev, "error %d : %x\n", ret, priv->flags);
 
 	return ret;
@@ -664,6 +658,12 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "cannot get clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
 	bus_speed = 100000; /* default 100 kHz */
 	ret = of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed);
 	if (ret < 0 && pdata && pdata->bus_speed)

drivers/i2c/busses/i2c-scmi.c

@@ -12,7 +12,6 @@
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/stddef.h>
-#include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/acpi.h>
 

drivers/i2c/busses/i2c-sh7760.c

@@ -11,7 +11,6 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/platform_device.h>

drivers/i2c/busses/i2c-simtec.c

@@ -20,7 +20,6 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

drivers/i2c/busses/i2c-sis630.c

@@ -45,7 +45,6 @@
 #include <linux/delay.h>
 #include <linux/pci.h>
 #include <linux/ioport.h>
-#include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/acpi.h>
 #include <linux/io.h>

drivers/i2c/busses/i2c-sis96x.c

@@ -36,7 +36,6 @@
 #include <linux/stddef.h>
 #include <linux/ioport.h>
 #include <linux/i2c.h>
-#include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 

drivers/i2c/busses/i2c-via.c

@@ -22,7 +22,6 @@
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/ioport.h>
-#include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 #include <linux/io.h>

drivers/i2c/busses/i2c-xiic.c

@@ -30,7 +30,6 @@
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/delay.h>

drivers/i2c/busses/i2c-xlr.c

@@ -11,7 +11,6 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/delay.h>
 #include <linux/errno.h>

drivers/i2c/busses/scx200_i2c.c

@@ -26,7 +26,6 @@
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
-#include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 #include <linux/io.h>

drivers/i2c/i2c-core.c

@@ -261,10 +261,9 @@ static int i2c_device_probe(struct device *dev)
 
 	acpi_dev_pm_attach(&client->dev, true);
 	status = driver->probe(client, i2c_match_id(driver->id_table, client));
-	if (status) {
-		i2c_set_clientdata(client, NULL);
+	if (status)
 		acpi_dev_pm_detach(&client->dev, true);
-	}
+
 	return status;
 }
 
@@ -272,7 +271,7 @@ static int i2c_device_remove(struct device *dev)
 {
 	struct i2c_client	*client = i2c_verify_client(dev);
 	struct i2c_driver	*driver;
-	int			status;
+	int status = 0;
 
 	if (!client || !dev->driver)
 		return 0;
@@ -281,12 +280,8 @@ static int i2c_device_remove(struct device *dev)
 	if (driver->remove) {
 		dev_dbg(dev, "remove\n");
 		status = driver->remove(client);
-	} else {
-		dev->driver = NULL;
-		status = 0;
 	}
-	if (status == 0)
-		i2c_set_clientdata(client, NULL);
+
 	acpi_dev_pm_detach(&client->dev, true);
 	return status;
 }

drivers/i2c/muxes/i2c-arb-gpio-challenge.c

@@ -19,7 +19,6 @@
 #include <linux/kernel.h>
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
-#include <linux/init.h>
 #include <linux/module.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>

drivers/i2c/muxes/i2c-mux-gpio.c

@@ -12,7 +12,6 @@
 #include <linux/i2c-mux.h>
 #include <linux/i2c-mux-gpio.h>
 #include <linux/platform_device.h>
-#include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/gpio.h>

drivers/i2c/muxes/i2c-mux-pca9541.c

@@ -17,7 +17,6 @@
  */
 
 #include <linux/module.h>
-#include <linux/init.h>
 #include <linux/jiffies.h>
 #include <linux/delay.h>
 #include <linux/slab.h>

drivers/i2c/muxes/i2c-mux-pca954x.c

@@ -40,7 +40,6 @@
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
 #include <linux/i2c/pca954x.h>
-#include <linux/init.h>
 #include <linux/module.h>
 #include <linux/of_gpio.h>
 #include <linux/slab.h>

drivers/i2c/muxes/i2c-mux-pinctrl.c

@@ -18,7 +18,6 @@
 
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
-#include <linux/init.h>
 #include <linux/module.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/i2c-mux-pinctrl.h>

include/linux/i2c.h

@@ -342,11 +342,25 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
 }
 #endif /* I2C_BOARDINFO */
 
-/*
+/**
+ * struct i2c_algorithm - represent I2C transfer method
+ * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
+ *   defined by the msgs array, with num messages available to transfer via
+ *   the adapter specified by adap.
+ * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
+ *   is not present, then the bus layer will try and convert the SMBus calls
+ *   into I2C transfers instead.
+ * @functionality: Return the flags that this algorithm/adapter pair supports
+ *   from the I2C_FUNC_* flags.
+ *
  * The following structs are for those who like to implement new bus drivers:
  * i2c_algorithm is the interface to a class of hardware solutions which can
  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
  * to name two of the most common.
+ *
+ * The return codes from the @master_xfer field should indicate the type of
+ * error code that occured during the transfer, as documented in the kernel
+ * Documentation file Documentation/i2c/fault-codes.
  */
 struct i2c_algorithm {
 	/* If an adapter algorithm can't do I2C-level access, set master_xfer