Merge branch 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "This pull request contains:

   - i2c core reorganization. One source file became too monolithic. It
     is now split up, yet we still have the same named object as the
     final output. This should ease maintenance.

   - new drivers: ZTE ZX2967 family, ASPEED 24XX/25XX

   - designware driver gained slave mode support

   - xgene-slimpro driver gained ACPI support

   - bigger overhaul for pca-platform driver

   - the algo-bit module now supports messages with enforced STOP

   - slightly bigger than usual set of driver updates and improvements

  and with much appreciated quality assurance from Andy Shevchenko"

* 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (51 commits)
  i2c: Provide a stub for i2c_detect_slave_mode()
  i2c: designware: Let slave adapter support be optional
  i2c: designware: Make HW init functions static
  i2c: designware: fix spelling mistakes
  i2c: pca-platform: propagate error from i2c_pca_add_numbered_bus
  i2c: pca-platform: correctly set algo_data.reset_chip
  i2c: acpi: Do not create i2c-clients for LNXVIDEO ACPI devices
  i2c: designware: enable SLAVE in platform module
  i2c: designware: add SLAVE mode functions
  i2c: zx2967: drop COMPILE_TEST dependency
  i2c: zx2967: always use the same device when printing errors
  i2c: pca-platform: use dev_warn/dev_info instead of printk
  i2c: pca-platform: use device managed allocations
  i2c: pca-platform: add devicetree awareness
  i2c: pca-platform: switch to struct gpio_desc
  dt-bindings: add bindings for i2c-pca-platform
  i2c: cadance: fix ctrl/addr reg write order
  i2c: zx2967: add i2c controller driver for ZTE's zx2967 family
  dt: bindings: add documentation for zx2967 family i2c controller
  i2c: algo-bit: add support for I2C_M_STOP
  ...

Documentation/devicetree/bindings/i2c/i2c-aspeed.txt

+Device tree configuration for the I2C busses on the AST24XX and AST25XX SoCs.
+
+Required Properties:
+- #address-cells	: should be 1
+- #size-cells		: should be 0
+- reg			: address offset and range of bus
+- compatible		: should be "aspeed,ast2400-i2c-bus"
+			  or "aspeed,ast2500-i2c-bus"
+- clocks		: root clock of bus, should reference the APB
+			  clock
+- interrupts		: interrupt number
+- interrupt-parent	: interrupt controller for bus, should reference a
+			  aspeed,ast2400-i2c-ic or aspeed,ast2500-i2c-ic
+			  interrupt controller
+
+Optional Properties:
+- bus-frequency	: frequency of the bus clock in Hz defaults to 100 kHz when not
+		  specified
+- multi-master	: states that there is another master active on this bus.
+
+Example:
+
+i2c {
+	compatible = "simple-bus";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	ranges = <0 0x1e78a000 0x1000>;
+
+	i2c_ic: interrupt-controller@0 {
+		#interrupt-cells = <1>;
+		compatible = "aspeed,ast2400-i2c-ic";
+		reg = <0x0 0x40>;
+		interrupts = <12>;
+		interrupt-controller;
+	};
+
+	i2c0: i2c-bus@40 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		#interrupt-cells = <1>;
+		reg = <0x40 0x40>;
+		compatible = "aspeed,ast2400-i2c-bus";
+		clocks = <&clk_apb>;
+		bus-frequency = <100000>;
+		interrupts = <0>;
+		interrupt-parent = <&i2c_ic>;
+	};
+};

Documentation/devicetree/bindings/i2c/i2c-designware.txt

@@ -20,7 +20,7 @@ Optional properties :
  - i2c-sda-falling-time-ns : should contain the SDA falling time in nanoseconds.
    This value which is by default 300ns is used to compute the tHIGH period.
 
-Example :
+Examples :
 
 	i2c@f0000 {
 		#address-cells = <1>;
@@ -43,3 +43,17 @@ Example :
 		i2c-sda-falling-time-ns = <300>;
 		i2c-scl-falling-time-ns = <300>;
 	};
+
+	i2c@1120000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x2000 0x100>;
+		clock-frequency = <400000>;
+		clocks = <&i2cclk>;
+		interrupts = <0>;
+
+		eeprom@64 {
+			compatible = "linux,slave-24c02";
+			reg = <0x40000064>;
+		};
+	};

Documentation/devicetree/bindings/i2c/i2c-pca-platform.txt

+* NXP PCA PCA9564/PCA9665 I2C controller
+
+The PCA9564/PCA9665 serves as an interface between most standard
+parallel-bus microcontrollers/microprocessors and the serial I2C-bus
+and allows the parallel bus system to communicate bi-directionally
+with the I2C-bus.
+
+Required properties :
+
+ - reg : Offset and length of the register set for the device
+ - compatible : one of "nxp,pca9564" or "nxp,pca9665"
+
+Optional properties
+ - interrupts : the interrupt number
+ - interrupt-parent : the phandle for the interrupt controller.
+   If an interrupt is not specified polling will be used.
+ - reset-gpios : gpio specifier for gpio connected to RESET_N pin. As the line
+   is active low, it should be marked GPIO_ACTIVE_LOW.
+ - clock-frequency : I2C bus frequency.
+
+Example:
+	i2c0: i2c@80000 {
+		compatible = "nxp,pca9564";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x80000 0x4>;
+		reset-gpios = <&gpio1 0 GPIO_ACTIVE_LOW>;
+		clock-frequency = <100000>;
+	};

Documentation/devicetree/bindings/i2c/i2c-zx2967.txt

+ZTE zx2967 I2C controller
+
+Required properties:
+ - compatible: must be "zte,zx296718-i2c"
+ - reg: physical address and length of the device registers
+ - interrupts: a single interrupt specifier
+ - clocks: clock for the device
+ - #address-cells: should be <1>
+ - #size-cells: should be <0>
+ - clock-frequency: the desired I2C bus clock frequency.
+
+Examples:
+
+	i2c@112000 {
+		compatible = "zte,zx296718-i2c";
+		reg = <0x00112000 0x1000>;
+		interrupts = <GIC_SPI 112 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&osc24m>;
+		#address-cells = <1>
+		#size-cells = <0>;
+		clock-frequency = <1600000>;
+	};

Documentation/driver-api/i2c.rst

@@ -41,5 +41,8 @@ i2c_adapter devices which don't support those I2C operations.
 .. kernel-doc:: drivers/i2c/i2c-boardinfo.c
    :functions: i2c_register_board_info
 
-.. kernel-doc:: drivers/i2c/i2c-core.c
+.. kernel-doc:: drivers/i2c/i2c-core-base.c
+   :export:
+
+.. kernel-doc:: drivers/i2c/i2c-core-smbus.c
    :export:

Documentation/i2c/busses/i2c-i801

@@ -34,6 +34,8 @@ Supported adapters:
   * Intel Broxton (SOC)
   * Intel Lewisburg (PCH)
   * Intel Gemini Lake (SOC)
+  * Intel Cannon Lake-H (PCH)
+  * Intel Cannon Lake-LP (PCH)
    Datasheets: Publicly available at the Intel website
 
 On Intel Patsburg and later chipsets, both the normal host SMBus controller

Documentation/i2c/dev-interface

@@ -191,7 +191,7 @@ checking on future transactions.)
 4* Other ioctl() calls are converted to in-kernel function calls by
 i2c-dev. Examples include I2C_FUNCS, which queries the I2C adapter
 functionality using i2c.h:i2c_get_functionality(), and I2C_SMBUS, which
-performs an SMBus transaction using i2c-core.c:i2c_smbus_xfer().
+performs an SMBus transaction using i2c-core-smbus.c:i2c_smbus_xfer().
 
 The i2c-dev driver is responsible for checking all the parameters that
 come from user-space for validity. After this point, there is no
@@ -200,13 +200,13 @@ and calls that would have been performed by kernel I2C chip drivers
 directly. This means that I2C bus drivers don't need to implement
 anything special to support access from user-space.
 
-5* These i2c-core.c/i2c.h functions are wrappers to the actual
-implementation of your I2C bus driver. Each adapter must declare
-callback functions implementing these standard calls.
-i2c.h:i2c_get_functionality() calls i2c_adapter.algo->functionality(),
-while i2c-core.c:i2c_smbus_xfer() calls either
+5* These i2c.h functions are wrappers to the actual implementation of
+your I2C bus driver. Each adapter must declare callback functions
+implementing these standard calls. i2c.h:i2c_get_functionality() calls
+i2c_adapter.algo->functionality(), while
+i2c-core-smbus.c:i2c_smbus_xfer() calls either
 adapter.algo->smbus_xfer() if it is implemented, or if not,
-i2c-core.c:i2c_smbus_xfer_emulated() which in turn calls
+i2c-core-smbus.c:i2c_smbus_xfer_emulated() which in turn calls
 i2c_adapter.algo->master_xfer().
 
 After your I2C bus driver has processed these requests, execution runs

MAINTAINERS

@@ -1139,6 +1139,18 @@ F:	arch/arm/mach-aspeed/
 F:	arch/arm/boot/dts/aspeed-*
 F:	drivers/*/*aspeed*
 
+ARM/ASPEED I2C DRIVER
+M:	Brendan Higgins <brendanhiggins@google.com>
+R:	Benjamin Herrenschmidt <benh@kernel.crashing.org>
+R:	Joel Stanley <joel@jms.id.au>
+L:	linux-i2c@vger.kernel.org
+L:	openbmc@lists.ozlabs.org
+S:	Maintained
+F:	drivers/irqchip/irq-aspeed-i2c-ic.c
+F:	drivers/i2c/busses/i2c-aspeed.c
+F:	Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2400-i2c-ic.txt
+F:	Documentation/devicetree/bindings/i2c/i2c-aspeed.txt
+
 ARM/ATMEL AT91RM9200, AT91SAM9 AND SAMA5 SOC SUPPORT
 M:	Nicolas Ferre <nicolas.ferre@microchip.com>
 M:	Alexandre Belloni <alexandre.belloni@free-electrons.com>
@@ -6382,6 +6394,7 @@ M:	Mika Westerberg <mika.westerberg@linux.intel.com>
 L:	linux-i2c@vger.kernel.org
 L:	linux-acpi@vger.kernel.org
 S:	Maintained
+F:	drivers/i2c/i2c-core-acpi.c
 
 I2C-TAOS-EVM DRIVER
 M:	Jean Delvare <jdelvare@suse.com>

drivers/i2c/Makefile

@@ -4,6 +4,11 @@
 
 obj-$(CONFIG_I2C_BOARDINFO)	+= i2c-boardinfo.o
 obj-$(CONFIG_I2C)		+= i2c-core.o
+i2c-core-objs 			:= i2c-core-base.o i2c-core-smbus.o
+i2c-core-$(CONFIG_ACPI)		+= i2c-core-acpi.o
+i2c-core-$(CONFIG_I2C_SLAVE) 	+= i2c-core-slave.o
+i2c-core-$(CONFIG_OF) 		+= i2c-core-of.o
+
 obj-$(CONFIG_I2C_SMBUS)		+= i2c-smbus.o
 obj-$(CONFIG_I2C_CHARDEV)	+= i2c-dev.o
 obj-$(CONFIG_I2C_MUX)		+= i2c-mux.o
@@ -12,4 +17,4 @@ obj-$(CONFIG_I2C_STUB)		+= i2c-stub.o
 obj-$(CONFIG_I2C_SLAVE_EEPROM)	+= i2c-slave-eeprom.o
 
 ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG
-CFLAGS_i2c-core.o := -Wno-deprecated-declarations
+CFLAGS_i2c-core-base.o := -Wno-deprecated-declarations

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

@@ -553,10 +553,17 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
 		nak_ok = pmsg->flags & I2C_M_IGNORE_NAK;
 		if (!(pmsg->flags & I2C_M_NOSTART)) {
 			if (i) {
-				bit_dbg(3, &i2c_adap->dev, "emitting "
-					"repeated start condition\n");
+				if (msgs[i - 1].flags & I2C_M_STOP) {
+					bit_dbg(3, &i2c_adap->dev,
+						"emitting enforced stop/start condition\n");
+					i2c_stop(adap);
+					i2c_start(adap);
+				} else {
+					bit_dbg(3, &i2c_adap->dev,
+						"emitting repeated start condition\n");
 					i2c_repstart(adap);
 				}
+			}
 			ret = bit_doAddress(i2c_adap, pmsg);
 			if ((ret != 0) && !nak_ok) {
 				bit_dbg(1, &i2c_adap->dev, "NAK from "

drivers/i2c/busses/Kconfig

@@ -129,6 +129,8 @@ config I2C_I801
 	    Broxton (SOC)
 	    Lewisburg (PCH)
 	    Gemini Lake (SOC)
+	    Cannon Lake-H (PCH)
+	    Cannon Lake-LP (PCH)
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-i801.
@@ -326,6 +328,16 @@ config I2C_POWERMAC
 
 comment "I2C system bus drivers (mostly embedded / system-on-chip)"
 
+config I2C_ASPEED
+	tristate "Aspeed I2C Controller"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	help
+	  If you say yes to this option, support will be included for the
+	  Aspeed I2C controller.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-aspeed.
+
 config I2C_AT91
 	tristate "Atmel AT91 I2C Two-Wire interface (TWI)"
 	depends on ARCH_AT91
@@ -474,11 +486,22 @@ config I2C_DESIGNWARE_PLATFORM
 	depends on (ACPI && COMMON_CLK) || !ACPI
 	help
 	  If you say yes to this option, support will be included for the
-	  Synopsys DesignWare I2C adapter. Only master mode is supported.
+	  Synopsys DesignWare I2C adapter.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware-platform.
 
+config I2C_DESIGNWARE_SLAVE
+	bool "Synopsys DesignWare Slave"
+	select I2C_SLAVE
+	depends on I2C_DESIGNWARE_PLATFORM
+	help
+	  If you say yes to this option, support will be included for the
+	  Synopsys DesignWare I2C slave adapter.
+
+	  This is not a standalone module, this module compiles together with
+	  i2c-designware-core.
+
 config I2C_DESIGNWARE_PCI
 	tristate "Synopsys DesignWare PCI"
 	depends on PCI
@@ -1258,4 +1281,13 @@ config I2C_OPAL
 	  This driver can also be built as a module. If so, the module will be
 	  called as i2c-opal.
 
+config I2C_ZX2967
+	tristate "ZTE ZX2967 I2C support"
+	depends on ARCH_ZX
+	default y
+	help
+	  Selecting this option will add ZX2967 I2C driver.
+	  This driver can also be built as a module. If so, the module will be
+	  called i2c-zx2967.
+
 endmenu

drivers/i2c/busses/Makefile

@@ -29,6 +29,7 @@ obj-$(CONFIG_I2C_HYDRA)		+= i2c-hydra.o
 obj-$(CONFIG_I2C_POWERMAC)	+= i2c-powermac.o
 
 # Embedded system I2C/SMBus host controller drivers
+obj-$(CONFIG_I2C_ASPEED)	+= i2c-aspeed.o
 obj-$(CONFIG_I2C_AT91)		+= i2c-at91.o
 obj-$(CONFIG_I2C_AU1550)	+= i2c-au1550.o
 obj-$(CONFIG_I2C_AXXIA)		+= i2c-axxia.o
@@ -40,6 +41,10 @@ obj-$(CONFIG_I2C_CBUS_GPIO)	+= i2c-cbus-gpio.o
 obj-$(CONFIG_I2C_CPM)		+= i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)	+= i2c-davinci.o
 obj-$(CONFIG_I2C_DESIGNWARE_CORE)	+= i2c-designware-core.o
+i2c-designware-core-objs := i2c-designware-common.o i2c-designware-master.o
+ifeq ($(CONFIG_I2C_DESIGNWARE_SLAVE),y)
+i2c-designware-core-objs += i2c-designware-slave.o
+endif
 obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)	+= i2c-designware-platform.o
 i2c-designware-platform-objs := i2c-designware-platdrv.o
 i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
@@ -102,6 +107,7 @@ obj-$(CONFIG_I2C_XILINX)	+= i2c-xiic.o
 obj-$(CONFIG_I2C_XLR)		+= i2c-xlr.o
 obj-$(CONFIG_I2C_XLP9XX)	+= i2c-xlp9xx.o
 obj-$(CONFIG_I2C_RCAR)		+= i2c-rcar.o
+obj-$(CONFIG_I2C_ZX2967)	+= i2c-zx2967.o
 
 # External I2C/SMBus adapter drivers
 obj-$(CONFIG_I2C_DIOLAN_U2C)	+= i2c-diolan-u2c.o

drivers/i2c/busses/i2c-at91.c

@@ -274,7 +274,7 @@ static void at91_twi_write_next_byte(struct at91_twi_dev *dev)
 		if (!dev->use_alt_cmd)
 			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
 
-	dev_dbg(dev->dev, "wrote 0x%x, to go %d\n", *dev->buf, dev->buf_len);
+	dev_dbg(dev->dev, "wrote 0x%x, to go %zu\n", *dev->buf, dev->buf_len);
 
 	++dev->buf;
 }
@@ -402,7 +402,7 @@ static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
 			dev->msg->flags &= ~I2C_M_RECV_LEN;
 			dev->buf_len += *dev->buf;
 			dev->msg->len = dev->buf_len + 1;
-			dev_dbg(dev->dev, "received block length %d\n",
+			dev_dbg(dev->dev, "received block length %zu\n",
 					 dev->buf_len);
 		} else {
 			/* abort and send the stop by reading one more byte */
@@ -415,7 +415,7 @@ static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
 	if (!dev->use_alt_cmd && dev->buf_len == 1)
 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);
 
-	dev_dbg(dev->dev, "read 0x%x, to go %d\n", *dev->buf, dev->buf_len);
+	dev_dbg(dev->dev, "read 0x%x, to go %zu\n", *dev->buf, dev->buf_len);
 
 	++dev->buf;
 }
@@ -622,7 +622,7 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
 	 * writing the corresponding bit into the Control Register.
 	 */
 
-	dev_dbg(dev->dev, "transfer: %s %d bytes.\n",
+	dev_dbg(dev->dev, "transfer: %s %zu bytes.\n",
 		(dev->msg->flags & I2C_M_RD) ? "read" : "write", dev->buf_len);
 
 	reinit_completion(&dev->cmd_complete);
@@ -1083,13 +1083,17 @@ static int at91_twi_probe(struct platform_device *pdev)
 		dev_err(dev->dev, "no clock defined\n");
 		return -ENODEV;
 	}
-	clk_prepare_enable(dev->clk);
+	rc = clk_prepare_enable(dev->clk);
+	if (rc)
+		return rc;
 
 	if (dev->dev->of_node) {
 		rc = at91_twi_configure_dma(dev, phy_addr);
-		if (rc == -EPROBE_DEFER)
+		if (rc == -EPROBE_DEFER) {
+			clk_disable_unprepare(dev->clk);
 			return rc;
 		}
+	}
 
 	if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",
 				  &dev->fifo_size)) {

drivers/i2c/busses/i2c-cadence.c

@@ -405,14 +405,14 @@ 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 */
 	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);
-	/* Set the slave address in address register - triggers operation */
-	cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
-						CDNS_I2C_ADDR_OFFSET);
 	cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
 }
 

drivers/i2c/busses/i2c-designware-common.c

+/*
+ * Synopsys DesignWare I2C adapter driver.
+ *
+ * Based on the TI DAVINCI I2C adapter driver.
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software Inc.
+ * Copyright (C) 2009 Provigent Ltd.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+
+#include "i2c-designware-core.h"
+
+static char *abort_sources[] = {
+	[ABRT_7B_ADDR_NOACK] =
+		"slave address not acknowledged (7bit mode)",
+	[ABRT_10ADDR1_NOACK] =
+		"first address byte not acknowledged (10bit mode)",
+	[ABRT_10ADDR2_NOACK] =
+		"second address byte not acknowledged (10bit mode)",
+	[ABRT_TXDATA_NOACK] =
+		"data not acknowledged",
+	[ABRT_GCALL_NOACK] =
+		"no acknowledgement for a general call",
+	[ABRT_GCALL_READ] =
+		"read after general call",
+	[ABRT_SBYTE_ACKDET] =
+		"start byte acknowledged",
+	[ABRT_SBYTE_NORSTRT] =
+		"trying to send start byte when restart is disabled",
+	[ABRT_10B_RD_NORSTRT] =
+		"trying to read when restart is disabled (10bit mode)",
+	[ABRT_MASTER_DIS] =
+		"trying to use disabled adapter",
+	[ARB_LOST] =
+		"lost arbitration",
+	[ABRT_SLAVE_FLUSH_TXFIFO] =
+		"read command so flush old data in the TX FIFO",
+	[ABRT_SLAVE_ARBLOST] =
+		"slave lost the bus while transmitting data to a remote master",
+	[ABRT_SLAVE_RD_INTX] =
+		"incorrect slave-transmitter mode configuration",
+};
+
+u32 dw_readl(struct dw_i2c_dev *dev, int offset)
+{
+	u32 value;
+
+	if (dev->flags & ACCESS_16BIT)
+		value = readw_relaxed(dev->base + offset) |
+			(readw_relaxed(dev->base + offset + 2) << 16);
+	else
+		value = readl_relaxed(dev->base + offset);
+
+	if (dev->flags & ACCESS_SWAP)
+		return swab32(value);
+	else
+		return value;
+}
+
+void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
+{
+	if (dev->flags & ACCESS_SWAP)
+		b = swab32(b);
+
+	if (dev->flags & ACCESS_16BIT) {
+		writew_relaxed((u16)b, dev->base + offset);
+		writew_relaxed((u16)(b >> 16), dev->base + offset + 2);
+	} else {
+		writel_relaxed(b, dev->base + offset);
+	}
+}
+
+u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
+{
+	/*
+	 * DesignWare I2C core doesn't seem to have solid strategy to meet
+	 * the tHD;STA timing spec.  Configuring _HCNT based on tHIGH spec
+	 * will result in violation of the tHD;STA spec.
+	 */
+	if (cond)
+		/*
+		 * Conditional expression:
+		 *
+		 *   IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
+		 *
+		 * This is based on the DW manuals, and represents an ideal
+		 * configuration.  The resulting I2C bus speed will be
+		 * faster than any of the others.
+		 *
+		 * If your hardware is free from tHD;STA issue, try this one.
+		 */
+		return (ic_clk * tSYMBOL + 500000) / 1000000 - 8 + offset;
+	else
+		/*
+		 * Conditional expression:
+		 *
+		 *   IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
+		 *
+		 * This is just experimental rule; the tHD;STA period turned
+		 * out to be proportinal to (_HCNT + 3).  With this setting,
+		 * we could meet both tHIGH and tHD;STA timing specs.
+		 *
+		 * If unsure, you'd better to take this alternative.
+		 *
+		 * The reason why we need to take into account "tf" here,
+		 * is the same as described in i2c_dw_scl_lcnt().
+		 */
+		return (ic_clk * (tSYMBOL + tf) + 500000) / 1000000
+			- 3 + offset;
+}
+
+u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
+{
+	/*
+	 * Conditional expression:
+	 *
+	 *   IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
+	 *
+	 * DW I2C core starts counting the SCL CNTs for the LOW period
+	 * of the SCL clock (tLOW) as soon as it pulls the SCL line.
+	 * In order to meet the tLOW timing spec, we need to take into
+	 * account the fall time of SCL signal (tf).  Default tf value
+	 * should be 0.3 us, for safety.
+	 */
+	return ((ic_clk * (tLOW + tf) + 500000) / 1000000) - 1 + offset;
+}
+
+void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
+{
+	dw_writel(dev, enable, DW_IC_ENABLE);
+}
+
+void __i2c_dw_enable_and_wait(struct dw_i2c_dev *dev, bool enable)
+{
+	int timeout = 100;
+
+	do {
+		__i2c_dw_enable(dev, enable);
+		if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
+			return;
+
+		/*
+		 * Wait 10 times the signaling period of the highest I2C
+		 * transfer supported by the driver (for 400KHz this is
+		 * 25us) as described in the DesignWare I2C databook.
+		 */
+		usleep_range(25, 250);
+	} while (timeout--);
+
+	dev_warn(dev->dev, "timeout in %sabling adapter\n",
+		 enable ? "en" : "dis");
+}
+
+unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
+{
+	/*
+	 * Clock is not necessary if we got LCNT/HCNT values directly from
+	 * the platform code.
+	 */
+	if (WARN_ON_ONCE(!dev->get_clk_rate_khz))
+		return 0;
+	return dev->get_clk_rate_khz(dev);
+}
+
+int i2c_dw_acquire_lock(struct dw_i2c_dev *dev)
+{
+	int ret;
+
+	if (!dev->acquire_lock)
+		return 0;
+
+	ret = dev->acquire_lock(dev);
+	if (!ret)
+		return 0;
+
+	dev_err(dev->dev, "couldn't acquire bus ownership\n");
+
+	return ret;
+}
+
+void i2c_dw_release_lock(struct dw_i2c_dev *dev)
+{
+	if (dev->release_lock)
+		dev->release_lock(dev);
+}
+
+/*
+ * Waiting for bus not busy
+ */
+int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
+{
+	int timeout = TIMEOUT;
+
+	while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
+		if (timeout <= 0) {
+			dev_warn(dev->dev, "timeout waiting for bus ready\n");
+			return -ETIMEDOUT;
+		}
+		timeout--;
+		usleep_range(1000, 1100);
+	}
+
+	return 0;
+}
+
+int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
+{
+	unsigned long abort_source = dev->abort_source;
+	int i;
+
+	if (abort_source & DW_IC_TX_ABRT_NOACK) {
+		for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
+			dev_dbg(dev->dev,
+				"%s: %s\n", __func__, abort_sources[i]);
+		return -EREMOTEIO;
+	}
+
+	for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
+		dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
+
+	if (abort_source & DW_IC_TX_ARB_LOST)
+		return -EAGAIN;
+	else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
+		return -EINVAL; /* wrong msgs[] data */
+	else
+		return -EIO;
+}
+
+u32 i2c_dw_func(struct i2c_adapter *adap)
+{
+	struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+
+	return dev->functionality;
+}
+
+void i2c_dw_disable(struct dw_i2c_dev *dev)
+{
+	/* Disable controller */
+	__i2c_dw_enable_and_wait(dev, false);
+
+	/* Disable all interupts */
+	dw_writel(dev, 0, DW_IC_INTR_MASK);
+	dw_readl(dev, DW_IC_CLR_INTR);
+}
+
+void i2c_dw_disable_int(struct dw_i2c_dev *dev)
+{
+	dw_writel(dev, 0, DW_IC_INTR_MASK);
+}
+
+u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev)
+{
+	return dw_readl(dev, DW_IC_COMP_PARAM_1);
+}
+EXPORT_SYMBOL_GPL(i2c_dw_read_comp_param);
+
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
+MODULE_LICENSE("GPL");

drivers/i2c/busses/i2c-designware-core.h

 /*
- * Synopsys DesignWare I2C adapter driver (master only).
+ * Synopsys DesignWare I2C adapter driver.
  *
  * Based on the TI DAVINCI I2C adapter driver.
  *
@@ -37,9 +37,152 @@
 #define DW_IC_CON_SPEED_FAST		0x4
 #define DW_IC_CON_SPEED_HIGH		0x6
 #define DW_IC_CON_SPEED_MASK		0x6
+#define DW_IC_CON_10BITADDR_SLAVE		0x8
 #define DW_IC_CON_10BITADDR_MASTER	0x10
 #define DW_IC_CON_RESTART_EN		0x20
 #define DW_IC_CON_SLAVE_DISABLE		0x40
+#define DW_IC_CON_STOP_DET_IFADDRESSED		0x80
+#define DW_IC_CON_TX_EMPTY_CTRL		0x100
+#define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL		0x200
+
+/*
+ * Registers offset
+ */
+#define DW_IC_CON		0x0
+#define DW_IC_TAR		0x4
+#define DW_IC_SAR		0x8
+#define DW_IC_DATA_CMD		0x10
+#define DW_IC_SS_SCL_HCNT	0x14
+#define DW_IC_SS_SCL_LCNT	0x18
+#define DW_IC_FS_SCL_HCNT	0x1c
+#define DW_IC_FS_SCL_LCNT	0x20
+#define DW_IC_HS_SCL_HCNT	0x24
+#define DW_IC_HS_SCL_LCNT	0x28
+#define DW_IC_INTR_STAT		0x2c
+#define DW_IC_INTR_MASK		0x30
+#define DW_IC_RAW_INTR_STAT	0x34
+#define DW_IC_RX_TL		0x38
+#define DW_IC_TX_TL		0x3c
+#define DW_IC_CLR_INTR		0x40
+#define DW_IC_CLR_RX_UNDER	0x44
+#define DW_IC_CLR_RX_OVER	0x48
+#define DW_IC_CLR_TX_OVER	0x4c
+#define DW_IC_CLR_RD_REQ	0x50
+#define DW_IC_CLR_TX_ABRT	0x54
+#define DW_IC_CLR_RX_DONE	0x58
+#define DW_IC_CLR_ACTIVITY	0x5c
+#define DW_IC_CLR_STOP_DET	0x60
+#define DW_IC_CLR_START_DET	0x64
+#define DW_IC_CLR_GEN_CALL	0x68
+#define DW_IC_ENABLE		0x6c
+#define DW_IC_STATUS		0x70
+#define DW_IC_TXFLR		0x74
+#define DW_IC_RXFLR		0x78
+#define DW_IC_SDA_HOLD		0x7c
+#define DW_IC_TX_ABRT_SOURCE	0x80
+#define DW_IC_ENABLE_STATUS	0x9c
+#define DW_IC_CLR_RESTART_DET	0xa8
+#define DW_IC_COMP_PARAM_1	0xf4
+#define DW_IC_COMP_VERSION	0xf8
+#define DW_IC_SDA_HOLD_MIN_VERS	0x3131312A
+#define DW_IC_COMP_TYPE		0xfc
+#define DW_IC_COMP_TYPE_VALUE	0x44570140
+
+#define DW_IC_INTR_RX_UNDER	0x001
+#define DW_IC_INTR_RX_OVER	0x002
+#define DW_IC_INTR_RX_FULL	0x004
+#define DW_IC_INTR_TX_OVER	0x008
+#define DW_IC_INTR_TX_EMPTY	0x010
+#define DW_IC_INTR_RD_REQ	0x020
+#define DW_IC_INTR_TX_ABRT	0x040
+#define DW_IC_INTR_RX_DONE	0x080
+#define DW_IC_INTR_ACTIVITY	0x100
+#define DW_IC_INTR_STOP_DET	0x200
+#define DW_IC_INTR_START_DET	0x400
+#define DW_IC_INTR_GEN_CALL	0x800
+#define DW_IC_INTR_RESTART_DET	0x1000
+
+#define DW_IC_INTR_DEFAULT_MASK		(DW_IC_INTR_RX_FULL | \
+					 DW_IC_INTR_TX_ABRT | \
+					 DW_IC_INTR_STOP_DET)
+#define DW_IC_INTR_MASTER_MASK		(DW_IC_INTR_DEFAULT_MASK | \
+					 DW_IC_INTR_TX_EMPTY)
+#define DW_IC_INTR_SLAVE_MASK		(DW_IC_INTR_DEFAULT_MASK | \
+					 DW_IC_INTR_RX_DONE | \
+					 DW_IC_INTR_RX_UNDER | \
+					 DW_IC_INTR_RD_REQ)
+
+#define DW_IC_STATUS_ACTIVITY		0x1
+#define DW_IC_STATUS_TFE		BIT(2)
+#define DW_IC_STATUS_MASTER_ACTIVITY	BIT(5)
+#define DW_IC_STATUS_SLAVE_ACTIVITY	BIT(6)
+
+#define DW_IC_SDA_HOLD_RX_SHIFT		16
+#define DW_IC_SDA_HOLD_RX_MASK		GENMASK(23, DW_IC_SDA_HOLD_RX_SHIFT)
+
+#define DW_IC_ERR_TX_ABRT	0x1
+
+#define DW_IC_TAR_10BITADDR_MASTER BIT(12)
+
+#define DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH	(BIT(2) | BIT(3))
+#define DW_IC_COMP_PARAM_1_SPEED_MODE_MASK	GENMASK(3, 2)
+
+/*
+ * status codes
+ */
+#define STATUS_IDLE			0x0
+#define STATUS_WRITE_IN_PROGRESS	0x1
+#define STATUS_READ_IN_PROGRESS		0x2
+
+#define TIMEOUT			20 /* ms */
+
+/*
+ * operation modes
+ */
+#define DW_IC_MASTER		0
+#define DW_IC_SLAVE		1
+
+/*
+ * Hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
+ *
+ * Only expected abort codes are listed here
+ * refer to the datasheet for the full list
+ */
+#define ABRT_7B_ADDR_NOACK	0
+#define ABRT_10ADDR1_NOACK	1
+#define ABRT_10ADDR2_NOACK	2
+#define ABRT_TXDATA_NOACK	3
+#define ABRT_GCALL_NOACK	4
+#define ABRT_GCALL_READ		5
+#define ABRT_SBYTE_ACKDET	7
+#define ABRT_SBYTE_NORSTRT	9
+#define ABRT_10B_RD_NORSTRT	10
+#define ABRT_MASTER_DIS		11
+#define ARB_LOST		12
+#define ABRT_SLAVE_FLUSH_TXFIFO	13
+#define ABRT_SLAVE_ARBLOST	14
+#define ABRT_SLAVE_RD_INTX	15
+
+#define DW_IC_TX_ABRT_7B_ADDR_NOACK	(1UL << ABRT_7B_ADDR_NOACK)
+#define DW_IC_TX_ABRT_10ADDR1_NOACK	(1UL << ABRT_10ADDR1_NOACK)
+#define DW_IC_TX_ABRT_10ADDR2_NOACK	(1UL << ABRT_10ADDR2_NOACK)
+#define DW_IC_TX_ABRT_TXDATA_NOACK	(1UL << ABRT_TXDATA_NOACK)
+#define DW_IC_TX_ABRT_GCALL_NOACK	(1UL << ABRT_GCALL_NOACK)
+#define DW_IC_TX_ABRT_GCALL_READ	(1UL << ABRT_GCALL_READ)
+#define DW_IC_TX_ABRT_SBYTE_ACKDET	(1UL << ABRT_SBYTE_ACKDET)
+#define DW_IC_TX_ABRT_SBYTE_NORSTRT	(1UL << ABRT_SBYTE_NORSTRT)
+#define DW_IC_TX_ABRT_10B_RD_NORSTRT	(1UL << ABRT_10B_RD_NORSTRT)
+#define DW_IC_TX_ABRT_MASTER_DIS	(1UL << ABRT_MASTER_DIS)
+#define DW_IC_TX_ARB_LOST		(1UL << ARB_LOST)
+#define DW_IC_RX_ABRT_SLAVE_RD_INTX	(1UL << ABRT_SLAVE_RD_INTX)
+#define DW_IC_RX_ABRT_SLAVE_ARBLOST	(1UL << ABRT_SLAVE_ARBLOST)
+#define DW_IC_RX_ABRT_SLAVE_FLUSH_TXFIFO	(1UL << ABRT_SLAVE_FLUSH_TXFIFO)
+
+#define DW_IC_TX_ABRT_NOACK		(DW_IC_TX_ABRT_7B_ADDR_NOACK | \
+					 DW_IC_TX_ABRT_10ADDR1_NOACK | \
+					 DW_IC_TX_ABRT_10ADDR2_NOACK | \
+					 DW_IC_TX_ABRT_TXDATA_NOACK | \
+					 DW_IC_TX_ABRT_GCALL_NOACK)
 
 
 /**
@@ -48,8 +191,9 @@
  * @base: IO registers pointer
  * @cmd_complete: tx completion indicator
  * @clk: input reference clock
+ * @slave: represent an I2C slave device
  * @cmd_err: run time hadware error code
- * @msgs: points to an array of messages currently being transfered
+ * @msgs: points to an array of messages currently being transferred
  * @msgs_num: the number of elements in msgs
  * @msg_write_idx: the element index of the current tx message in the msgs
  *	array
@@ -64,6 +208,7 @@
  * @abort_source: copy of the TX_ABRT_SOURCE register
  * @irq: interrupt number for the i2c master
  * @adapter: i2c subsystem adapter node
+ * @slave_cfg: configuration for the slave device
  * @tx_fifo_depth: depth of the hardware tx fifo
  * @rx_fifo_depth: depth of the hardware rx fifo
  * @rx_outstanding: current master-rx elements in tx fifo
@@ -80,6 +225,10 @@
  * @acquire_lock: function to acquire a hardware lock on the bus
  * @release_lock: function to release a hardware lock on the bus
  * @pm_disabled: true if power-management should be disabled for this i2c-bus
+ * @disable: function to disable the controller
+ * @disable_int: function to disable all interrupts
+ * @init: function to initialize the I2C hardware
+ * @mode: operation mode - DW_IC_MASTER or DW_IC_SLAVE
  *
  * HCNT and LCNT parameters can be used if the platform knows more accurate
  * values than the one computed based only on the input clock frequency.
@@ -91,6 +240,7 @@ struct dw_i2c_dev {
 	struct completion	cmd_complete;
 	struct clk		*clk;
 	struct reset_control	*rst;
+	struct i2c_client		*slave;
 	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);
 	struct dw_pci_controller *controller;
 	int			cmd_err;
@@ -110,6 +260,7 @@ struct dw_i2c_dev {
 	struct i2c_adapter	adapter;
 	u32			functionality;
 	u32			master_cfg;
+	u32			slave_cfg;
 	unsigned int		tx_fifo_depth;
 	unsigned int		rx_fifo_depth;
 	int			rx_outstanding;
@@ -129,6 +280,10 @@ struct dw_i2c_dev {
 	int			(*acquire_lock)(struct dw_i2c_dev *dev);
 	void			(*release_lock)(struct dw_i2c_dev *dev);
 	bool			pm_disabled;
+	void			(*disable)(struct dw_i2c_dev *dev);
+	void			(*disable_int)(struct dw_i2c_dev *dev);
+	int			(*init)(struct dw_i2c_dev *dev);
+	int			mode;
 };
 
 #define ACCESS_SWAP		0x00000001
@@ -137,11 +292,28 @@ struct dw_i2c_dev {
 
 #define MODEL_CHERRYTRAIL	0x00000100
 
-extern int i2c_dw_init(struct dw_i2c_dev *dev);
-extern void i2c_dw_disable(struct dw_i2c_dev *dev);
-extern void i2c_dw_disable_int(struct dw_i2c_dev *dev);
+u32 dw_readl(struct dw_i2c_dev *dev, int offset);
+void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset);
+u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset);
+u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
+void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable);
+void __i2c_dw_enable_and_wait(struct dw_i2c_dev *dev, bool enable);
+unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev);
+int i2c_dw_acquire_lock(struct dw_i2c_dev *dev);
+void i2c_dw_release_lock(struct dw_i2c_dev *dev);
+int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev);
+int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev);
+u32 i2c_dw_func(struct i2c_adapter *adap);
+void i2c_dw_disable(struct dw_i2c_dev *dev);
+void i2c_dw_disable_int(struct dw_i2c_dev *dev);
+
 extern u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev);
 extern int i2c_dw_probe(struct dw_i2c_dev *dev);
+#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_SLAVE)
+extern int i2c_dw_probe_slave(struct dw_i2c_dev *dev);
+#else
+static inline int i2c_dw_probe_slave(struct dw_i2c_dev *dev) { return -EINVAL; }
+#endif
 
 #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
 extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);

drivers/i2c/busses/i2c-designware-pcidrv.c

@@ -187,16 +187,19 @@ static struct dw_pci_controller dw_pci_controllers[] = {
 static int i2c_dw_pci_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct dw_i2c_dev *i_dev = pci_get_drvdata(pdev);
+
+	i_dev->disable(i_dev);
 
-	i2c_dw_disable(pci_get_drvdata(pdev));
 	return 0;
 }
 
 static int i2c_dw_pci_resume(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct dw_i2c_dev *i_dev = pci_get_drvdata(pdev);
 
-	return i2c_dw_init(pci_get_drvdata(pdev));
+	return i_dev->init(i_dev);
 }
 #endif
 
@@ -296,7 +299,7 @@ static void i2c_dw_pci_remove(struct pci_dev *pdev)
 {
 	struct dw_i2c_dev *dev = pci_get_drvdata(pdev);
 
-	i2c_dw_disable(dev);
+	dev->disable(dev);
 	pm_runtime_forbid(&pdev->dev);
 	pm_runtime_get_noresume(&pdev->dev);
 

drivers/i2c/busses/i2c-designware-platdrv.c

 /*
- * Synopsys DesignWare I2C adapter driver (master only).
+ * Synopsys DesignWare I2C adapter driver.
  *
  * Based on the TI DAVINCI I2C adapter driver.
  *
@@ -21,27 +21,28 @@
  * ----------------------------------------------------------------------------
  *
  */
-#include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/clk-provider.h>
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dmi.h>
-#include <linux/i2c.h>
-#include <linux/clk.h>
-#include <linux/clk-provider.h>
-#include <linux/errno.h>
-#include <linux/sched.h>
 #include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
+#include <linux/platform_data/i2c-designware.h>
 #include <linux/platform_device.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
-#include <linux/io.h>
 #include <linux/reset.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
-#include <linux/acpi.h>
-#include <linux/platform_data/i2c-designware.h>
+
 #include "i2c-designware-core.h"
 
 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
@@ -171,6 +172,49 @@ static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 }
 #endif
 
+static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
+{
+	dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
+
+	dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
+			  DW_IC_CON_RESTART_EN;
+
+	dev->mode = DW_IC_MASTER;
+
+	switch (dev->clk_freq) {
+	case 100000:
+		dev->master_cfg |= DW_IC_CON_SPEED_STD;
+		break;
+	case 3400000:
+		dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
+		break;
+	default:
+		dev->master_cfg |= DW_IC_CON_SPEED_FAST;
+	}
+}
+
+static void i2c_dw_configure_slave(struct dw_i2c_dev *dev)
+{
+	dev->functionality = I2C_FUNC_SLAVE | DW_IC_DEFAULT_FUNCTIONALITY;
+
+	dev->slave_cfg = DW_IC_CON_RX_FIFO_FULL_HLD_CTRL |
+			 DW_IC_CON_RESTART_EN | DW_IC_CON_STOP_DET_IFADDRESSED |
+			 DW_IC_CON_SPEED_FAST;
+
+	dev->mode = DW_IC_SLAVE;
+
+	switch (dev->clk_freq) {
+	case 100000:
+		dev->slave_cfg |= DW_IC_CON_SPEED_STD;
+		break;
+	case 3400000:
+		dev->slave_cfg |= DW_IC_CON_SPEED_HIGH;
+		break;
+	default:
+		dev->slave_cfg |= DW_IC_CON_SPEED_FAST;
+	}
+}
+
 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare)
 {
 	if (IS_ERR(i_dev->clk))
@@ -209,11 +253,11 @@ static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id)
 static int dw_i2c_plat_probe(struct platform_device *pdev)
 {
 	struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
-	struct dw_i2c_dev *dev;
 	struct i2c_adapter *adap;
-	struct resource *mem;
-	int irq, r;
+	struct dw_i2c_dev *dev;
 	u32 acpi_speed, ht = 0;
+	struct resource *mem;
+	int irq, ret;
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
@@ -276,29 +320,18 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	    && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
 		dev_err(&pdev->dev,
 			"Only 100kHz, 400kHz, 1MHz and 3.4MHz supported");
-		r = -EINVAL;
+		ret = -EINVAL;
 		goto exit_reset;
 	}
 
-	r = i2c_dw_probe_lock_support(dev);
-	if (r)
+	ret = i2c_dw_probe_lock_support(dev);
+	if (ret)
 		goto exit_reset;
 
-	dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
-
-	dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
-			  DW_IC_CON_RESTART_EN;
-
-	switch (dev->clk_freq) {
-	case 100000:
-		dev->master_cfg |= DW_IC_CON_SPEED_STD;
-		break;
-	case 3400000:
-		dev->master_cfg |= DW_IC_CON_SPEED_HIGH;
-		break;
-	default:
-		dev->master_cfg |= DW_IC_CON_SPEED_FAST;
-	}
+	if (i2c_detect_slave_mode(&pdev->dev))
+		i2c_dw_configure_slave(dev);
+	else
+		i2c_dw_configure_master(dev);
 
 	dev->clk = devm_clk_get(&pdev->dev, NULL);
 	if (!i2c_dw_plat_prepare_clk(dev, true)) {
@@ -327,11 +360,15 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 		pm_runtime_enable(&pdev->dev);
 	}
 
-	r = i2c_dw_probe(dev);
-	if (r)
+	if (dev->mode == DW_IC_SLAVE)
+		ret = i2c_dw_probe_slave(dev);
+	else
+		ret = i2c_dw_probe(dev);
+
+	if (ret)
 		goto exit_probe;
 
-	return r;
+	return ret;
 
 exit_probe:
 	if (!dev->pm_disabled)
@@ -339,7 +376,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 exit_reset:
 	if (!IS_ERR_OR_NULL(dev->rst))
 		reset_control_assert(dev->rst);
-	return r;
+	return ret;
 }
 
 static int dw_i2c_plat_remove(struct platform_device *pdev)
@@ -350,7 +387,7 @@ static int dw_i2c_plat_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&dev->adapter);
 
-	i2c_dw_disable(dev);
+	dev->disable(dev);
 
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
@@ -394,7 +431,7 @@ static int dw_i2c_plat_suspend(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 
-	i2c_dw_disable(i_dev);
+	i_dev->disable(i_dev);
 	i2c_dw_plat_prepare_clk(i_dev, false);
 
 	return 0;
@@ -406,7 +443,7 @@ static int dw_i2c_plat_resume(struct device *dev)
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 
 	i2c_dw_plat_prepare_clk(i_dev, true);
-	i2c_dw_init(i_dev);
+	i_dev->init(i_dev);
 
 	return 0;
 }
@@ -423,7 +460,7 @@ static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
 #define DW_I2C_DEV_PMOPS NULL
 #endif
 
-/* work with hotplug and coldplug */
+/* Work with hotplug and coldplug */
 MODULE_ALIAS("platform:i2c_designware");
 
 static struct platform_driver dw_i2c_driver = {

drivers/i2c/busses/i2c-emev2.c

@@ -375,7 +375,9 @@ static int em_i2c_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->sclk))
 		return PTR_ERR(priv->sclk);
 
-	clk_prepare_enable(priv->sclk);
+	ret = clk_prepare_enable(priv->sclk);
+	if (ret)
+		return ret;
 
 	priv->adap.timeout = msecs_to_jiffies(100);
 	priv->adap.retries = 5;

drivers/i2c/busses/i2c-i801.c

@@ -66,6 +66,8 @@
  * Lewisburg Supersku (PCH)	0xa223	32	hard	yes	yes	yes
  * Kaby Lake PCH-H (PCH)	0xa2a3	32	hard	yes	yes	yes
  * Gemini Lake (SOC)		0x31d4	32	hard	yes	yes	yes
+ * Cannon Lake-H (PCH)		0xa323	32	hard	yes	yes	yes
+ * Cannon Lake-LP (PCH)		0x9da3	32	hard	yes	yes	yes
  *
  * Features supported by this driver:
  * Software PEC				no
@@ -226,10 +228,12 @@
 #define PCI_DEVICE_ID_INTEL_LYNXPOINT_LP_SMBUS		0x9c22
 #define PCI_DEVICE_ID_INTEL_WILDCATPOINT_LP_SMBUS	0x9ca2
 #define PCI_DEVICE_ID_INTEL_SUNRISEPOINT_LP_SMBUS	0x9d23
+#define PCI_DEVICE_ID_INTEL_CANNONLAKE_LP_SMBUS		0x9da3
 #define PCI_DEVICE_ID_INTEL_SUNRISEPOINT_H_SMBUS	0xa123
 #define PCI_DEVICE_ID_INTEL_LEWISBURG_SMBUS		0xa1a3
 #define PCI_DEVICE_ID_INTEL_LEWISBURG_SSKU_SMBUS	0xa223
 #define PCI_DEVICE_ID_INTEL_KABYLAKE_PCH_H_SMBUS	0xa2a3
+#define PCI_DEVICE_ID_INTEL_CANNONLAKE_H_SMBUS		0xa323
 
 struct i801_mux_config {
 	char *gpio_chip;
@@ -1026,6 +1030,8 @@ static const struct pci_device_id i801_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_LEWISBURG_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_LEWISBURG_SSKU_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_KABYLAKE_PCH_H_SMBUS) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CANNONLAKE_H_SMBUS) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CANNONLAKE_LP_SMBUS) },
 	{ 0, }
 };
 
@@ -1499,6 +1505,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	switch (dev->device) {
 	case PCI_DEVICE_ID_INTEL_SUNRISEPOINT_H_SMBUS:
 	case PCI_DEVICE_ID_INTEL_SUNRISEPOINT_LP_SMBUS:
+	case PCI_DEVICE_ID_INTEL_CANNONLAKE_H_SMBUS:
+	case PCI_DEVICE_ID_INTEL_CANNONLAKE_LP_SMBUS:
 	case PCI_DEVICE_ID_INTEL_LEWISBURG_SMBUS:
 	case PCI_DEVICE_ID_INTEL_LEWISBURG_SSKU_SMBUS:
 	case PCI_DEVICE_ID_INTEL_DNV_SMBUS:

drivers/i2c/busses/i2c-mxs.c

@@ -419,7 +419,7 @@ static int mxs_i2c_pio_setup_xfer(struct i2c_adapter *adap,
 
 		ret = mxs_i2c_pio_wait_xfer_end(i2c);
 		if (ret) {
-			dev_err(i2c->dev,
+			dev_dbg(i2c->dev,
 				"PIO: Failed to send SELECT command!\n");
 			goto cleanup;
 		}
@@ -431,7 +431,7 @@ static int mxs_i2c_pio_setup_xfer(struct i2c_adapter *adap,
 
 		ret = mxs_i2c_pio_wait_xfer_end(i2c);
 		if (ret) {
-			dev_err(i2c->dev,
+			dev_dbg(i2c->dev,
 				"PIO: Failed to send READ command!\n");
 			goto cleanup;
 		}
@@ -528,7 +528,7 @@ static int mxs_i2c_pio_setup_xfer(struct i2c_adapter *adap,
 			/* Wait for the end of the transfer. */
 			ret = mxs_i2c_pio_wait_xfer_end(i2c);
 			if (ret) {
-				dev_err(i2c->dev,
+				dev_dbg(i2c->dev,
 					"PIO: Failed to finish WRITE cmd!\n");
 				break;
 			}

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

@@ -22,14 +22,17 @@
 #include <linux/i2c-algo-pca.h>
 #include <linux/i2c-pca-platform.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <asm/irq.h>
 
 struct i2c_pca_pf_data {
 	void __iomem			*reg_base;
 	int				irq;	/* if 0, use polling */
-	int				gpio;
+	struct gpio_desc		*gpio;
 	wait_queue_head_t		wait;
 	struct i2c_adapter		adap;
 	struct i2c_algo_pca_data	algo_data;
@@ -104,17 +107,17 @@ static int i2c_pca_pf_waitforcompletion(void *pd)
 static void i2c_pca_pf_dummyreset(void *pd)
 {
 	struct i2c_pca_pf_data *i2c = pd;
-	printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n",
-		i2c->adap.name);
+
+	dev_warn(&i2c->adap.dev, "No reset-pin found. Chip may get stuck!\n");
 }
 
 static void i2c_pca_pf_resetchip(void *pd)
 {
 	struct i2c_pca_pf_data *i2c = pd;
 
-	gpio_set_value(i2c->gpio, 0);
+	gpiod_set_value(i2c->gpio, 1);
 	ndelay(100);
-	gpio_set_value(i2c->gpio, 1);
+	gpiod_set_value(i2c->gpio, 0);
 }
 
 static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id)
@@ -136,36 +139,27 @@ static int i2c_pca_pf_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct i2c_pca9564_pf_platform_data *platform_data =
 				dev_get_platdata(&pdev->dev);
+	struct device_node *np = pdev->dev.of_node;
 	int ret = 0;
 	int irq;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	irq = platform_get_irq(pdev, 0);
 	/* If irq is 0, we do polling. */
+	if (irq < 0)
+		irq = 0;
 
-	if (res == NULL) {
-		ret = -ENODEV;
-		goto e_print;
-	}
+	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
 
-	if (!request_mem_region(res->start, resource_size(res), res->name)) {
-		ret = -ENOMEM;
-		goto e_print;
-	}
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	i2c->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(i2c->reg_base))
+		return PTR_ERR(i2c->reg_base);
 
-	i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL);
-	if (!i2c) {
-		ret = -ENOMEM;
-		goto e_alloc;
-	}
 
 	init_waitqueue_head(&i2c->wait);
 
-	i2c->reg_base = ioremap(res->start, resource_size(res));
-	if (!i2c->reg_base) {
-		ret = -ENOMEM;
-		goto e_remap;
-	}
 	i2c->io_base = res->start;
 	i2c->io_size = resource_size(res);
 	i2c->irq = irq;
@@ -177,19 +171,42 @@ static int i2c_pca_pf_probe(struct platform_device *pdev)
 		 (unsigned long) res->start);
 	i2c->adap.algo_data = &i2c->algo_data;
 	i2c->adap.dev.parent = &pdev->dev;
+	i2c->adap.dev.of_node = np;
 
 	if (platform_data) {
 		i2c->adap.timeout = platform_data->timeout;
 		i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed;
-		i2c->gpio = platform_data->gpio;
+		if (gpio_is_valid(platform_data->gpio)) {
+			ret = devm_gpio_request_one(&pdev->dev,
+						    platform_data->gpio,
+						    GPIOF_ACTIVE_LOW,
+						    i2c->adap.name);
+			if (ret == 0) {
+				i2c->gpio = gpio_to_desc(platform_data->gpio);
+				gpiod_direction_output(i2c->gpio, 0);
+			} else {
+				dev_warn(&pdev->dev, "Registering gpio failed!\n");
+				i2c->gpio = NULL;
+			}
+		}
+	} else if (np) {
+		i2c->adap.timeout = HZ;
+		i2c->gpio = devm_gpiod_get_optional(&pdev->dev, "reset-gpios", GPIOD_OUT_LOW);
+		if (IS_ERR(i2c->gpio))
+			return PTR_ERR(i2c->gpio);
+		of_property_read_u32_index(np, "clock-frequency", 0,
+					   &i2c->algo_data.i2c_clock);
 	} else {
 		i2c->adap.timeout = HZ;
 		i2c->algo_data.i2c_clock = 59000;
-		i2c->gpio = -1;
+		i2c->gpio = NULL;
 	}
 
 	i2c->algo_data.data = i2c;
 	i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion;
+	if (i2c->gpio)
+		i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
+	else
 		i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset;
 
 	switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
@@ -208,52 +225,22 @@ static int i2c_pca_pf_probe(struct platform_device *pdev)
 		break;
 	}
 
-	/* Use gpio_is_valid() when in mainline */
-	if (i2c->gpio > -1) {
-		ret = gpio_request(i2c->gpio, i2c->adap.name);
-		if (ret == 0) {
-			gpio_direction_output(i2c->gpio, 1);
-			i2c->algo_data.reset_chip = i2c_pca_pf_resetchip;
-		} else {
-			printk(KERN_WARNING "%s: Registering gpio failed!\n",
-				i2c->adap.name);
-			i2c->gpio = ret;
-		}
-	}
-
 	if (irq) {
-		ret = request_irq(irq, i2c_pca_pf_handler,
+		ret = devm_request_irq(&pdev->dev, irq, i2c_pca_pf_handler,
 			IRQF_TRIGGER_FALLING, pdev->name, i2c);
 		if (ret)
-			goto e_reqirq;
+			return ret;
 	}
 
-	if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) {
-		ret = -ENODEV;
-		goto e_adapt;
-	}
+	ret = i2c_pca_add_numbered_bus(&i2c->adap);
+	if (ret)
+		return ret;
 
 	platform_set_drvdata(pdev, i2c);
 
-	printk(KERN_INFO "%s registered.\n", i2c->adap.name);
+	dev_info(&pdev->dev, "registered.\n");
 
 	return 0;
-
-e_adapt:
-	if (irq)
-		free_irq(irq, i2c);
-e_reqirq:
-	if (i2c->gpio > -1)
-		gpio_free(i2c->gpio);
-
-	iounmap(i2c->reg_base);
-e_remap:
-	kfree(i2c);
-e_alloc:
-	release_mem_region(res->start, resource_size(res));
-e_print:
-	printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret);
-	return ret;
 }
 
 static int i2c_pca_pf_remove(struct platform_device *pdev)
@@ -262,24 +249,24 @@ static int i2c_pca_pf_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&i2c->adap);
 
-	if (i2c->irq)
-		free_irq(i2c->irq, i2c);
-
-	if (i2c->gpio > -1)
-		gpio_free(i2c->gpio);
-
-	iounmap(i2c->reg_base);
-	release_mem_region(i2c->io_base, i2c->io_size);
-	kfree(i2c);
-
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id i2c_pca_of_match_table[] = {
+	{ .compatible = "nxp,pca9564" },
+	{ .compatible = "nxp,pca9665" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, i2c_pca_of_match_table);
+#endif
+
 static struct platform_driver i2c_pca_pf_driver = {
 	.probe = i2c_pca_pf_probe,
 	.remove = i2c_pca_pf_remove,
 	.driver = {
 		.name = "i2c-pca-platform",
+		.of_match_table = of_match_ptr(i2c_pca_of_match_table),
 	},
 };
 

drivers/i2c/busses/i2c-rcar.c

 /*
- * Driver for the Renesas RCar I2C unit
+ * Driver for the Renesas R-Car I2C unit
  *
  * Copyright (C) 2014-15 Wolfram Sang <wsa@sang-engineering.com>
  * Copyright (C) 2011-2015 Renesas Electronics Corporation
@@ -783,7 +783,12 @@ static int rcar_unreg_slave(struct i2c_client *slave)
 
 static u32 rcar_i2c_func(struct i2c_adapter *adap)
 {
-	/* This HW can't do SMBUS_QUICK and NOSTART */
+	/*
+	 * 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);
 }

drivers/i2c/busses/i2c-sh_mobile.c

@@ -24,7 +24,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
-#include <linux/i2c/i2c-sh_mobile.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -879,10 +878,10 @@ static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, struct sh_mobile
 
 static int sh_mobile_i2c_probe(struct platform_device *dev)
 {
-	struct i2c_sh_mobile_platform_data *pdata = dev_get_platdata(&dev->dev);
 	struct sh_mobile_i2c_data *pd;
 	struct i2c_adapter *adap;
 	struct resource *res;
+	const struct of_device_id *match;
 	int ret;
 	u32 bus_speed;
 
@@ -910,31 +909,19 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 	if (IS_ERR(pd->reg))
 		return PTR_ERR(pd->reg);
 
-	/* Use platform data bus speed or STANDARD_MODE */
 	ret = of_property_read_u32(dev->dev.of_node, "clock-frequency", &bus_speed);
 	pd->bus_speed = ret ? STANDARD_MODE : bus_speed;
-
 	pd->clks_per_count = 1;
 
-	if (dev->dev.of_node) {
-		const struct of_device_id *match;
-
 	match = of_match_device(sh_mobile_i2c_dt_ids, &dev->dev);
 	if (match) {
-			const struct sh_mobile_dt_config *config;
+		const struct sh_mobile_dt_config *config = match->data;
 
-			config = match->data;
 		pd->clks_per_count = config->clks_per_count;
 
 		if (config->setup)
 			config->setup(pd);
 	}
-	} else {
-		if (pdata && pdata->bus_speed)
-			pd->bus_speed = pdata->bus_speed;
-		if (pdata && pdata->clks_per_count)
-			pd->clks_per_count = pdata->clks_per_count;
-	}
 
 	/* The IIC blocks on SH-Mobile ARM processors
 	 * come with two new bits in ICIC.

drivers/i2c/busses/i2c-xlp9xx.c

@@ -393,6 +393,7 @@ static int xlp9xx_i2c_probe(struct platform_device *pdev)
 	init_completion(&priv->msg_complete);
 	priv->adapter.dev.parent = &pdev->dev;
 	priv->adapter.algo = &xlp9xx_i2c_algo;
+	priv->adapter.class = I2C_CLASS_HWMON;
 	ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
 	priv->adapter.dev.of_node = pdev->dev.of_node;
 	priv->dev = &pdev->dev;

drivers/i2c/i2c-core-of.c

+/*
+ * Linux I2C core OF support code
+ *
+ * Copyright (C) 2008 Jochen Friedrich <jochen@scram.de>
+ * based on a previous patch from Jon Smirl <jonsmirl@gmail.com>
+ *
+ * Copyright (C) 2013 Wolfram Sang <wsa@the-dreams.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <dt-bindings/i2c/i2c.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include "i2c-core.h"
+
+static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
+						 struct device_node *node)
+{
+	struct i2c_client *result;
+	struct i2c_board_info info = {};
+	struct dev_archdata dev_ad = {};
+	const __be32 *addr_be;
+	u32 addr;
+	int len;
+
+	dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
+
+	if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
+		dev_err(&adap->dev, "of_i2c: modalias failure on %s\n",
+			node->full_name);
+		return ERR_PTR(-EINVAL);
+	}
+
+	addr_be = of_get_property(node, "reg", &len);
+	if (!addr_be || (len < sizeof(*addr_be))) {
+		dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
+			node->full_name);
+		return ERR_PTR(-EINVAL);
+	}
+
+	addr = be32_to_cpup(addr_be);
+	if (addr & I2C_TEN_BIT_ADDRESS) {
+		addr &= ~I2C_TEN_BIT_ADDRESS;
+		info.flags |= I2C_CLIENT_TEN;
+	}
+
+	if (addr & I2C_OWN_SLAVE_ADDRESS) {
+		addr &= ~I2C_OWN_SLAVE_ADDRESS;
+		info.flags |= I2C_CLIENT_SLAVE;
+	}
+
+	if (i2c_check_addr_validity(addr, info.flags)) {
+		dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
+			addr, node->full_name);
+		return ERR_PTR(-EINVAL);
+	}
+
+	info.addr = addr;
+	info.of_node = of_node_get(node);
+	info.archdata = &dev_ad;
+
+	if (of_property_read_bool(node, "host-notify"))
+		info.flags |= I2C_CLIENT_HOST_NOTIFY;
+
+	if (of_get_property(node, "wakeup-source", NULL))
+		info.flags |= I2C_CLIENT_WAKE;
+
+	result = i2c_new_device(adap, &info);
+	if (result == NULL) {
+		dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
+			node->full_name);
+		of_node_put(node);
+		return ERR_PTR(-EINVAL);
+	}
+	return result;
+}
+
+void of_i2c_register_devices(struct i2c_adapter *adap)
+{
+	struct device_node *bus, *node;
+	struct i2c_client *client;
+
+	/* Only register child devices if the adapter has a node pointer set */
+	if (!adap->dev.of_node)
+		return;
+
+	dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
+
+	bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
+	if (!bus)
+		bus = of_node_get(adap->dev.of_node);
+
+	for_each_available_child_of_node(bus, node) {
+		if (of_node_test_and_set_flag(node, OF_POPULATED))
+			continue;
+
+		client = of_i2c_register_device(adap, node);
+		if (IS_ERR(client)) {
+			dev_warn(&adap->dev,
+				 "Failed to create I2C device for %s\n",
+				 node->full_name);
+			of_node_clear_flag(node, OF_POPULATED);
+		}
+	}
+
+	of_node_put(bus);
+}
+
+static int of_dev_node_match(struct device *dev, void *data)
+{
+	return dev->of_node == data;
+}
+
+/* must call put_device() when done with returned i2c_client device */
+struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
+{
+	struct device *dev;
+	struct i2c_client *client;
+
+	dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
+	if (!dev)
+		return NULL;
+
+	client = i2c_verify_client(dev);
+	if (!client)
+		put_device(dev);
+
+	return client;
+}
+EXPORT_SYMBOL(of_find_i2c_device_by_node);
+
+/* must call put_device() when done with returned i2c_adapter device */
+struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
+{
+	struct device *dev;
+	struct i2c_adapter *adapter;
+
+	dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
+	if (!dev)
+		return NULL;
+
+	adapter = i2c_verify_adapter(dev);
+	if (!adapter)
+		put_device(dev);
+
+	return adapter;
+}
+EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
+
+/* must call i2c_put_adapter() when done with returned i2c_adapter device */
+struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
+{
+	struct i2c_adapter *adapter;
+
+	adapter = of_find_i2c_adapter_by_node(node);
+	if (!adapter)
+		return NULL;
+
+	if (!try_module_get(adapter->owner)) {
+		put_device(&adapter->dev);
+		adapter = NULL;
+	}
+
+	return adapter;
+}
+EXPORT_SYMBOL(of_get_i2c_adapter_by_node);
+
+static const struct of_device_id*
+i2c_of_match_device_sysfs(const struct of_device_id *matches,
+				  struct i2c_client *client)
+{
+	const char *name;
+
+	for (; matches->compatible[0]; matches++) {
+		/*
+		 * Adding devices through the i2c sysfs interface provides us
+		 * a string to match which may be compatible with the device
+		 * tree compatible strings, however with no actual of_node the
+		 * of_match_device() will not match
+		 */
+		if (sysfs_streq(client->name, matches->compatible))
+			return matches;
+
+		name = strchr(matches->compatible, ',');
+		if (!name)
+			name = matches->compatible;
+		else
+			name++;
+
+		if (sysfs_streq(client->name, name))
+			return matches;
+	}
+
+	return NULL;
+}
+
+const struct of_device_id
+*i2c_of_match_device(const struct of_device_id *matches,
+		     struct i2c_client *client)
+{
+	const struct of_device_id *match;
+
+	if (!(client && matches))
+		return NULL;
+
+	match = of_match_device(matches, &client->dev);
+	if (match)
+		return match;
+
+	return i2c_of_match_device_sysfs(matches, client);
+}
+EXPORT_SYMBOL_GPL(i2c_of_match_device);
+
+#if IS_ENABLED(CONFIG_OF_DYNAMIC)
+static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
+			 void *arg)
+{
+	struct of_reconfig_data *rd = arg;
+	struct i2c_adapter *adap;
+	struct i2c_client *client;
+
+	switch (of_reconfig_get_state_change(action, rd)) {
+	case OF_RECONFIG_CHANGE_ADD:
+		adap = of_find_i2c_adapter_by_node(rd->dn->parent);
+		if (adap == NULL)
+			return NOTIFY_OK;	/* not for us */
+
+		if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
+			put_device(&adap->dev);
+			return NOTIFY_OK;
+		}
+
+		client = of_i2c_register_device(adap, rd->dn);
+		put_device(&adap->dev);
+
+		if (IS_ERR(client)) {
+			dev_err(&adap->dev, "failed to create client for '%s'\n",
+				 rd->dn->full_name);
+			of_node_clear_flag(rd->dn, OF_POPULATED);
+			return notifier_from_errno(PTR_ERR(client));
+		}
+		break;
+	case OF_RECONFIG_CHANGE_REMOVE:
+		/* already depopulated? */
+		if (!of_node_check_flag(rd->dn, OF_POPULATED))
+			return NOTIFY_OK;
+
+		/* find our device by node */
+		client = of_find_i2c_device_by_node(rd->dn);
+		if (client == NULL)
+			return NOTIFY_OK;	/* no? not meant for us */
+
+		/* unregister takes one ref away */
+		i2c_unregister_device(client);
+
+		/* and put the reference of the find */
+		put_device(&client->dev);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+struct notifier_block i2c_of_notifier = {
+	.notifier_call = of_i2c_notify,
+};
+#endif /* CONFIG_OF_DYNAMIC */

drivers/i2c/i2c-core-slave.c

+/*
+ * Linux I2C core slave support code
+ *
+ * Copyright (C) 2014 by Wolfram Sang <wsa@sang-engineering.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <dt-bindings/i2c/i2c.h>
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/of.h>
+
+#include "i2c-core.h"
+
+int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
+{
+	int ret;
+
+	if (!client || !slave_cb) {
+		WARN(1, "insufficient data\n");
+		return -EINVAL;
+	}
+
+	if (!(client->flags & I2C_CLIENT_SLAVE))
+		dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n",
+			 __func__);
+
+	if (!(client->flags & I2C_CLIENT_TEN)) {
+		/* Enforce stricter address checking */
+		ret = i2c_check_7bit_addr_validity_strict(client->addr);
+		if (ret) {
+			dev_err(&client->dev, "%s: invalid address\n", __func__);
+			return ret;
+		}
+	}
+
+	if (!client->adapter->algo->reg_slave) {
+		dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	client->slave_cb = slave_cb;
+
+	i2c_lock_adapter(client->adapter);
+	ret = client->adapter->algo->reg_slave(client);
+	i2c_unlock_adapter(client->adapter);
+
+	if (ret) {
+		client->slave_cb = NULL;
+		dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_slave_register);
+
+int i2c_slave_unregister(struct i2c_client *client)
+{
+	int ret;
+
+	if (!client->adapter->algo->unreg_slave) {
+		dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	i2c_lock_adapter(client->adapter);
+	ret = client->adapter->algo->unreg_slave(client);
+	i2c_unlock_adapter(client->adapter);
+
+	if (ret == 0)
+		client->slave_cb = NULL;
+	else
+		dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_slave_unregister);
+
+/**
+ * i2c_detect_slave_mode - detect operation mode
+ * @dev: The device owning the bus
+ *
+ * This checks the device nodes for an I2C slave by checking the address
+ * used in the reg property. If the address match the I2C_OWN_SLAVE_ADDRESS
+ * flag this means the device is configured to act as a I2C slave and it will
+ * be listening at that address.
+ *
+ * Returns true if an I2C own slave address is detected, otherwise returns
+ * false.
+ */
+bool i2c_detect_slave_mode(struct device *dev)
+{
+	if (IS_BUILTIN(CONFIG_OF) && dev->of_node) {
+		struct device_node *child;
+		u32 reg;
+
+		for_each_child_of_node(dev->of_node, child) {
+			of_property_read_u32(child, "reg", &reg);
+			if (reg & I2C_OWN_SLAVE_ADDRESS) {
+				of_node_put(child);
+				return true;
+			}
+		}
+	} else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) {
+		dev_dbg(dev, "ACPI slave is not supported yet\n");
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(i2c_detect_slave_mode);

drivers/i2c/i2c-core.h

@@ -27,3 +27,27 @@ extern struct rw_semaphore	__i2c_board_lock;
 extern struct list_head	__i2c_board_list;
 extern int		__i2c_first_dynamic_bus_num;
 
+int i2c_check_addr_validity(unsigned addr, unsigned short flags);
+int i2c_check_7bit_addr_validity_strict(unsigned short addr);
+
+#ifdef CONFIG_ACPI
+void i2c_acpi_register_devices(struct i2c_adapter *adap);
+#else /* CONFIG_ACPI */
+static inline void i2c_acpi_register_devices(struct i2c_adapter *adap) { }
+#endif /* CONFIG_ACPI */
+extern struct notifier_block i2c_acpi_notifier;
+
+#ifdef CONFIG_ACPI_I2C_OPREGION
+int i2c_acpi_install_space_handler(struct i2c_adapter *adapter);
+void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter);
+#else /* CONFIG_ACPI_I2C_OPREGION */
+static inline int i2c_acpi_install_space_handler(struct i2c_adapter *adapter) { return 0; }
+static inline void i2c_acpi_remove_space_handler(struct i2c_adapter *adapter) { }
+#endif /* CONFIG_ACPI_I2C_OPREGION */
+
+#ifdef CONFIG_OF
+void of_i2c_register_devices(struct i2c_adapter *adap);
+#else
+static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
+#endif
+extern struct notifier_block i2c_of_notifier;

drivers/i2c/i2c-stub.c

@@ -16,6 +16,7 @@
 */
 
 #define DEBUG 1
+#define pr_fmt(fmt) "i2c-stub: " fmt
 
 #include <linux/errno.h>
 #include <linux/i2c.h>
@@ -342,7 +343,7 @@ static int __init i2c_stub_allocate_banks(int i)
 	if (!chip->bank_words)
 		return -ENOMEM;
 
-	pr_debug("i2c-stub: Allocated %u banks of %u words each (registers 0x%02x to 0x%02x)\n",
+	pr_debug("Allocated %u banks of %u words each (registers 0x%02x to 0x%02x)\n",
 		 chip->bank_mask, chip->bank_size, chip->bank_start,
 		 chip->bank_end);
 
@@ -363,28 +364,27 @@ static int __init i2c_stub_init(void)
 	int i, ret;
 
 	if (!chip_addr[0]) {
-		pr_err("i2c-stub: Please specify a chip address\n");
+		pr_err("Please specify a chip address\n");
 		return -ENODEV;
 	}
 
 	for (i = 0; i < MAX_CHIPS && chip_addr[i]; i++) {
 		if (chip_addr[i] < 0x03 || chip_addr[i] > 0x77) {
-			pr_err("i2c-stub: Invalid chip address 0x%02x\n",
+			pr_err("Invalid chip address 0x%02x\n",
 			       chip_addr[i]);
 			return -EINVAL;
 		}
 
-		pr_info("i2c-stub: Virtual chip at 0x%02x\n", chip_addr[i]);
+		pr_info("Virtual chip at 0x%02x\n", chip_addr[i]);
 	}
 
 	/* Allocate memory for all chips at once */
 	stub_chips_nr = i;
 	stub_chips = kcalloc(stub_chips_nr, sizeof(struct stub_chip),
 			     GFP_KERNEL);
-	if (!stub_chips) {
-		pr_err("i2c-stub: Out of memory\n");
+	if (!stub_chips)
 		return -ENOMEM;
-	}
+
 	for (i = 0; i < stub_chips_nr; i++) {
 		INIT_LIST_HEAD(&stub_chips[i].smbus_blocks);
 

include/linux/i2c.h

@@ -295,6 +295,8 @@ static inline int i2c_slave_event(struct i2c_client *client,
 {
 	return client->slave_cb(client, event, val);
 }
+#else
+static inline bool i2c_detect_slave_mode(struct device *dev) { return false; }
 #endif
 
 /**

include/linux/i2c/i2c-sh_mobile.h

-#ifndef __I2C_SH_MOBILE_H__
-#define __I2C_SH_MOBILE_H__
-
-#include <linux/platform_device.h>
-
-struct i2c_sh_mobile_platform_data {
-	unsigned long bus_speed;
-	unsigned int clks_per_count;
-};
-
-#endif /* __I2C_SH_MOBILE_H__ */