Merge branch 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "Summary:

   - legacy PM code removed from the core, there were no users anymore
     (thanks to Lars-Peter Clausen)

   - new driver for Broadcom iProc

   - bigger driver updates for designware, rk3x, cadence, ocores

   - a bunch of smaller updates and bugfixes"

* 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (31 commits)
  i2c: ocores: rework clk code to handle NULL cookie
  i2c: designware-baytrail: another fixup for proper Kconfig dependencies
  i2c: fix reference to functionality constants definition
  i2c: iproc: Add Broadcom iProc I2C Driver
  i2c: designware-pci: update Intel copyright line
  i2c: ocores: add common clock support
  i2c: hix5hd2: add COMPILE_TEST
  i2c: clarify comments about the dev_released completion
  i2c: ocores: fix clock-frequency binding usage
  i2c: tegra: Maintain CPU endianness
  i2c: designware-baytrail: use proper Kconfig dependencies
  i2c: designware: Do not calculate SCL timing parameters needlessly
  i2c: do not try to load modules for of-registered devices
  i2c: designware: Add Intel Baytrail PMIC I2C bus support
  i2c: designware: Add i2c bus locking support
  of: i2c: Add i2c-mux-idle-disconnect DT property to PCA954x mux driver
  i2c: designware: use {readl|writel}_relaxed instead of readl/writel
  i2c: designware-pci: no need to provide clk_khz
  i2c: designware-pci: remove Moorestown support
  i2c: imx: whitespace and checkpatch cleanup
  ...

Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt

+Broadcom iProc I2C controller
+
+Required properties:
+
+- compatible:
+    Must be "brcm,iproc-i2c"
+
+- reg:
+    Define the base and range of the I/O address space that contain the iProc
+    I2C controller registers
+
+- interrupts:
+    Should contain the I2C interrupt
+
+- clock-frequency:
+    This is the I2C bus clock. Need to be either 100000 or 400000
+
+- #address-cells:
+    Always 1 (for I2C addresses)
+
+- #size-cells:
+    Always 0
+
+Example:
+	i2c0: i2c@18008000 {
+		compatible = "brcm,iproc-i2c";
+		reg = <0x18008000 0x100>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupts = <GIC_SPI 85 IRQ_TYPE_NONE>;
+		clock-frequency = <100000>;
+
+		codec: wm8750@1a {
+			compatible = "wlf,wm8750";
+			reg = <0x1a>;
+		};
+	};

Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt

@@ -16,6 +16,9 @@ Required Properties:
 Optional Properties:
 
   - reset-gpios: Reference to the GPIO connected to the reset input.
+  - i2c-mux-idle-disconnect: Boolean; if defined, forces mux to disconnect all
+    children in idle state. This is necessary for example, if there are several
+    multiplexers on the bus and the devices behind them use same I2C addresses.
 
 
 Example:

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

@@ -4,24 +4,60 @@ Required properties:
 - compatible      : "opencores,i2c-ocores" or "aeroflexgaisler,i2cmst"
 - reg             : bus address start and address range size of device
 - interrupts      : interrupt number
-- clock-frequency : frequency of bus clock in Hz
+- clocks          : handle to the controller clock; see the note below.
+                    Mutually exclusive with opencores,ip-clock-frequency
+- opencores,ip-clock-frequency: frequency of the controller clock in Hz;
+                    see the note below. Mutually exclusive with clocks
 - #address-cells  : should be <1>
 - #size-cells     : should be <0>
 
 Optional properties:
+- clock-frequency : frequency of bus clock in Hz; see the note below.
+                    Defaults to 100 KHz when the property is not specified
 - reg-shift       : device register offsets are shifted by this value
 - reg-io-width    : io register width in bytes (1, 2 or 4)
 - regstep         : deprecated, use reg-shift above
 
-Example:
+Note
+clock-frequency property is meant to control the bus frequency for i2c bus
+drivers, but it was incorrectly used to specify i2c controller input clock
+frequency. So the following rules are set to fix this situation:
+- if clock-frequency is present and neither opencores,ip-clock-frequency nor
+  clocks are, then clock-frequency specifies i2c controller clock frequency.
+  This is to keep backwards compatibility with setups using old DTB. i2c bus
+  frequency is fixed at 100 KHz.
+- if clocks is present it specifies i2c controller clock. clock-frequency
+  property specifies i2c bus frequency.
+- if opencores,ip-clock-frequency is present it specifies i2c controller
+  clock frequency. clock-frequency property specifies i2c bus frequency.
 
+Examples:
+
+	i2c0: ocores@a0000000 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "opencores,i2c-ocores";
+		reg = <0xa0000000 0x8>;
+		interrupts = <10>;
+		opencores,ip-clock-frequency = <20000000>;
+
+		reg-shift = <0>;	/* 8 bit registers */
+		reg-io-width = <1>;	/* 8 bit read/write */
+
+		dummy@60 {
+			compatible = "dummy";
+			reg = <0x60>;
+		};
+	};
+or
 	i2c0: ocores@a0000000 {
 		#address-cells = <1>;
 		#size-cells = <0>;
 		compatible = "opencores,i2c-ocores";
 		reg = <0xa0000000 0x8>;
 		interrupts = <10>;
-		clock-frequency = <20000000>;
+		clocks = <&osc>;
+		clock-frequency = <400000>; /* i2c bus frequency 400 KHz */
 
 		reg-shift = <0>;	/* 8 bit registers */
 		reg-io-width = <1>;	/* 8 bit read/write */

Documentation/devicetree/bindings/i2c/i2c-rk3x.txt

@@ -21,6 +21,17 @@ Required on RK3066, RK3188 :
 Optional properties :
 
  - clock-frequency : SCL frequency to use (in Hz). If omitted, 100kHz is used.
+ - i2c-scl-rising-time-ns : Number of nanoseconds the SCL signal takes to rise
+	(t(r) in I2C specification). If not specified this is assumed to be
+	the maximum the specification allows(1000 ns for Standard-mode,
+	300 ns for Fast-mode) which might cause slightly slower communication.
+ - i2c-scl-falling-time-ns : Number of nanoseconds the SCL signal takes to fall
+	(t(f) in the I2C specification). If not specified this is assumed to
+	be the maximum the specification allows (300 ns) which might cause
+	slightly slower communication.
+ - i2c-sda-falling-time-ns : Number of nanoseconds the SDA signal takes to fall
+	(t(f) in the I2C specification). If not specified we'll use the SCL
+	value since they are the same in nearly all cases.
 
 Example:
 
@@ -39,4 +50,7 @@ i2c0: i2c@2002d000 {
 
 	clock-names = "i2c";
 	clocks = <&cru PCLK_I2C0>;
+
+	i2c-scl-rising-time-ns = <800>;
+	i2c-scl-falling-time-ns = <100>;
 };

Documentation/devicetree/bindings/i2c/trivial-devices.txt

@@ -61,9 +61,8 @@ fsl,sgtl5000		SGTL5000: Ultra Low-Power Audio Codec
 gmt,g751		G751: Digital Temperature Sensor and Thermal Watchdog with Two-Wire Interface
 infineon,slb9635tt	Infineon SLB9635 (Soft-) I2C TPM (old protocol, max 100khz)
 infineon,slb9645tt	Infineon SLB9645 I2C TPM (new protocol, max 400khz)
-isl,isl12057		Intersil ISL12057 I2C RTC Chip
-isil,isl29028           (deprecated, use isl)
-isl,isl29028            Intersil ISL29028 Ambient Light and Proximity Sensor
+isil,isl12057		Intersil ISL12057 I2C RTC Chip
+isil,isl29028		Intersil ISL29028 Ambient Light and Proximity Sensor
 maxim,ds1050		5 Bit Programmable, Pulse-Width Modulator
 maxim,max1237		Low-Power, 4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
 maxim,max6625		9-Bit/12-Bit Temperature Sensors with I²C-Compatible Serial Interface

Documentation/i2c/functionality

@@ -12,7 +12,7 @@ FUNCTIONALITY CONSTANTS
 -----------------------
 
 For the most up-to-date list of functionality constants, please check
-<linux/i2c.h>!
+<uapi/linux/i2c.h>!
 
   I2C_FUNC_I2C                    Plain i2c-level commands (Pure SMBus
                                   adapters typically can not do these)

drivers/i2c/busses/Kconfig

@@ -79,7 +79,7 @@ config I2C_AMD8111
 
 config I2C_HIX5HD2
 	tristate "Hix5hd2 high-speed I2C driver"
-	depends on ARCH_HIX5HD2
+	depends on ARCH_HIX5HD2 || COMPILE_TEST
 	help
 	  Say Y here to include support for high-speed I2C controller in the
 	  Hisilicon based hix5hd2 SoCs.
@@ -372,6 +372,16 @@ config I2C_BCM2835
 	  This support is also available as a module.  If so, the module
 	  will be called i2c-bcm2835.
 
+config I2C_BCM_IPROC
+	tristate "Broadcom iProc I2C controller"
+	depends on ARCH_BCM_IPROC || COMPILE_TEST
+	default ARCH_BCM_IPROC
+	help
+	  If you say yes to this option, support will be included for the
+	  Broadcom iProc I2C controller.
+
+	  If you don't know what to do here, say N.
+
 config I2C_BCM_KONA
 	tristate "BCM Kona I2C adapter"
 	depends on ARCH_BCM_MOBILE
@@ -465,6 +475,16 @@ config I2C_DESIGNWARE_PCI
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware-pci.
 
+config I2C_DESIGNWARE_BAYTRAIL
+	bool "Intel Baytrail I2C semaphore support"
+	depends on I2C_DESIGNWARE_PLATFORM && IOSF_MBI=y && ACPI
+	help
+	  This driver enables managed host access to the PMIC I2C bus on select
+	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
+	  the host to request uninterrupted access to the PMIC's I2C bus from
+	  the platform firmware controlling it. You should say Y if running on
+	  a BayTrail system using the AXP288.
+
 config I2C_EFM32
 	tristate "EFM32 I2C controller"
 	depends on ARCH_EFM32 || COMPILE_TEST

drivers/i2c/busses/Makefile

@@ -33,6 +33,7 @@ obj-$(CONFIG_I2C_AT91)		+= i2c-at91.o
 obj-$(CONFIG_I2C_AU1550)	+= i2c-au1550.o
 obj-$(CONFIG_I2C_AXXIA)		+= i2c-axxia.o
 obj-$(CONFIG_I2C_BCM2835)	+= i2c-bcm2835.o
+obj-$(CONFIG_I2C_BCM_IPROC)	+= i2c-bcm-iproc.o
 obj-$(CONFIG_I2C_BLACKFIN_TWI)	+= i2c-bfin-twi.o
 obj-$(CONFIG_I2C_CADENCE)	+= i2c-cadence.o
 obj-$(CONFIG_I2C_CBUS_GPIO)	+= i2c-cbus-gpio.o
@@ -41,6 +42,7 @@ obj-$(CONFIG_I2C_DAVINCI)	+= i2c-davinci.o
 obj-$(CONFIG_I2C_DESIGNWARE_CORE)	+= i2c-designware-core.o
 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
 obj-$(CONFIG_I2C_DESIGNWARE_PCI)	+= i2c-designware-pci.o
 i2c-designware-pci-objs := i2c-designware-pcidrv.o
 obj-$(CONFIG_I2C_EFM32)		+= i2c-efm32.o

drivers/i2c/busses/i2c-bcm-iproc.c

+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; 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/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define CFG_OFFSET                   0x00
+#define CFG_RESET_SHIFT              31
+#define CFG_EN_SHIFT                 30
+#define CFG_M_RETRY_CNT_SHIFT        16
+#define CFG_M_RETRY_CNT_MASK         0x0f
+
+#define TIM_CFG_OFFSET               0x04
+#define TIM_CFG_MODE_400_SHIFT       31
+
+#define M_FIFO_CTRL_OFFSET           0x0c
+#define M_FIFO_RX_FLUSH_SHIFT        31
+#define M_FIFO_TX_FLUSH_SHIFT        30
+#define M_FIFO_RX_CNT_SHIFT          16
+#define M_FIFO_RX_CNT_MASK           0x7f
+#define M_FIFO_RX_THLD_SHIFT         8
+#define M_FIFO_RX_THLD_MASK          0x3f
+
+#define M_CMD_OFFSET                 0x30
+#define M_CMD_START_BUSY_SHIFT       31
+#define M_CMD_STATUS_SHIFT           25
+#define M_CMD_STATUS_MASK            0x07
+#define M_CMD_STATUS_SUCCESS         0x0
+#define M_CMD_STATUS_LOST_ARB        0x1
+#define M_CMD_STATUS_NACK_ADDR       0x2
+#define M_CMD_STATUS_NACK_DATA       0x3
+#define M_CMD_STATUS_TIMEOUT         0x4
+#define M_CMD_PROTOCOL_SHIFT         9
+#define M_CMD_PROTOCOL_MASK          0xf
+#define M_CMD_PROTOCOL_BLK_WR        0x7
+#define M_CMD_PROTOCOL_BLK_RD        0x8
+#define M_CMD_PEC_SHIFT              8
+#define M_CMD_RD_CNT_SHIFT           0
+#define M_CMD_RD_CNT_MASK            0xff
+
+#define IE_OFFSET                    0x38
+#define IE_M_RX_FIFO_FULL_SHIFT      31
+#define IE_M_RX_THLD_SHIFT           30
+#define IE_M_START_BUSY_SHIFT        28
+
+#define IS_OFFSET                    0x3c
+#define IS_M_RX_FIFO_FULL_SHIFT      31
+#define IS_M_RX_THLD_SHIFT           30
+#define IS_M_START_BUSY_SHIFT        28
+
+#define M_TX_OFFSET                  0x40
+#define M_TX_WR_STATUS_SHIFT         31
+#define M_TX_DATA_SHIFT              0
+#define M_TX_DATA_MASK               0xff
+
+#define M_RX_OFFSET                  0x44
+#define M_RX_STATUS_SHIFT            30
+#define M_RX_STATUS_MASK             0x03
+#define M_RX_PEC_ERR_SHIFT           29
+#define M_RX_DATA_SHIFT              0
+#define M_RX_DATA_MASK               0xff
+
+#define I2C_TIMEOUT_MESC             100
+#define M_TX_RX_FIFO_SIZE            64
+
+enum bus_speed_index {
+	I2C_SPD_100K = 0,
+	I2C_SPD_400K,
+};
+
+struct bcm_iproc_i2c_dev {
+	struct device *device;
+	int irq;
+
+	void __iomem *base;
+
+	struct i2c_adapter adapter;
+
+	struct completion done;
+	int xfer_is_done;
+};
+
+/*
+ * Can be expanded in the future if more interrupt status bits are utilized
+ */
+#define ISR_MASK (1 << IS_M_START_BUSY_SHIFT)
+
+static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
+{
+	struct bcm_iproc_i2c_dev *iproc_i2c = data;
+	u32 status = readl(iproc_i2c->base + IS_OFFSET);
+
+	status &= ISR_MASK;
+
+	if (!status)
+		return IRQ_NONE;
+
+	writel(status, iproc_i2c->base + IS_OFFSET);
+	iproc_i2c->xfer_is_done = 1;
+	complete_all(&iproc_i2c->done);
+
+	return IRQ_HANDLED;
+}
+
+static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
+				      struct i2c_msg *msg)
+{
+	u32 val;
+
+	val = readl(iproc_i2c->base + M_CMD_OFFSET);
+	val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK;
+
+	switch (val) {
+	case M_CMD_STATUS_SUCCESS:
+		return 0;
+
+	case M_CMD_STATUS_LOST_ARB:
+		dev_dbg(iproc_i2c->device, "lost bus arbitration\n");
+		return -EAGAIN;
+
+	case M_CMD_STATUS_NACK_ADDR:
+		dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr);
+		return -ENXIO;
+
+	case M_CMD_STATUS_NACK_DATA:
+		dev_dbg(iproc_i2c->device, "NAK data\n");
+		return -ENXIO;
+
+	case M_CMD_STATUS_TIMEOUT:
+		dev_dbg(iproc_i2c->device, "bus timeout\n");
+		return -ETIMEDOUT;
+
+	default:
+		dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val);
+		return -EIO;
+	}
+}
+
+static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c,
+					 struct i2c_msg *msg)
+{
+	int ret, i;
+	u8 addr;
+	u32 val;
+	unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MESC);
+
+	/* need to reserve one byte in the FIFO for the slave address */
+	if (msg->len > M_TX_RX_FIFO_SIZE - 1) {
+		dev_err(iproc_i2c->device,
+			"only support data length up to %u bytes\n",
+			M_TX_RX_FIFO_SIZE - 1);
+		return -EOPNOTSUPP;
+	}
+
+	/* check if bus is busy */
+	if (!!(readl(iproc_i2c->base + M_CMD_OFFSET) &
+	       BIT(M_CMD_START_BUSY_SHIFT))) {
+		dev_warn(iproc_i2c->device, "bus is busy\n");
+		return -EBUSY;
+	}
+
+	/* format and load slave address into the TX FIFO */
+	addr = msg->addr << 1 | (msg->flags & I2C_M_RD ? 1 : 0);
+	writel(addr, iproc_i2c->base + M_TX_OFFSET);
+
+	/* for a write transaction, load data into the TX FIFO */
+	if (!(msg->flags & I2C_M_RD)) {
+		for (i = 0; i < msg->len; i++) {
+			val = msg->buf[i];
+
+			/* mark the last byte */
+			if (i == msg->len - 1)
+				val |= 1 << M_TX_WR_STATUS_SHIFT;
+
+			writel(val, iproc_i2c->base + M_TX_OFFSET);
+		}
+	}
+
+	/* mark as incomplete before starting the transaction */
+	reinit_completion(&iproc_i2c->done);
+	iproc_i2c->xfer_is_done = 0;
+
+	/*
+	 * Enable the "start busy" interrupt, which will be triggered after the
+	 * transaction is done, i.e., the internal start_busy bit, transitions
+	 * from 1 to 0.
+	 */
+	writel(1 << IE_M_START_BUSY_SHIFT, iproc_i2c->base + IE_OFFSET);
+
+	/*
+	 * Now we can activate the transfer. For a read operation, specify the
+	 * number of bytes to read
+	 */
+	val = 1 << M_CMD_START_BUSY_SHIFT;
+	if (msg->flags & I2C_M_RD) {
+		val |= (M_CMD_PROTOCOL_BLK_RD << M_CMD_PROTOCOL_SHIFT) |
+		       (msg->len << M_CMD_RD_CNT_SHIFT);
+	} else {
+		val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT);
+	}
+	writel(val, iproc_i2c->base + M_CMD_OFFSET);
+
+	time_left = wait_for_completion_timeout(&iproc_i2c->done, time_left);
+
+	/* disable all interrupts */
+	writel(0, iproc_i2c->base + IE_OFFSET);
+	/* read it back to flush the write */
+	readl(iproc_i2c->base + IE_OFFSET);
+
+	/* make sure the interrupt handler isn't running */
+	synchronize_irq(iproc_i2c->irq);
+
+	if (!time_left && !iproc_i2c->xfer_is_done) {
+		dev_err(iproc_i2c->device, "transaction timed out\n");
+
+		/* flush FIFOs */
+		val = (1 << M_FIFO_RX_FLUSH_SHIFT) |
+		      (1 << M_FIFO_TX_FLUSH_SHIFT);
+		writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET);
+		return -ETIMEDOUT;
+	}
+
+	ret = bcm_iproc_i2c_check_status(iproc_i2c, msg);
+	if (ret) {
+		/* flush both TX/RX FIFOs */
+		val = (1 << M_FIFO_RX_FLUSH_SHIFT) |
+		      (1 << M_FIFO_TX_FLUSH_SHIFT);
+		writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET);
+		return ret;
+	}
+
+	/*
+	 * For a read operation, we now need to load the data from FIFO
+	 * into the memory buffer
+	 */
+	if (msg->flags & I2C_M_RD) {
+		for (i = 0; i < msg->len; i++) {
+			msg->buf[i] = (readl(iproc_i2c->base + M_RX_OFFSET) >>
+				      M_RX_DATA_SHIFT) & M_RX_DATA_MASK;
+		}
+	}
+
+	return 0;
+}
+
+static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
+			      struct i2c_msg msgs[], int num)
+{
+	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter);
+	int ret, i;
+
+	/* go through all messages */
+	for (i = 0; i < num; i++) {
+		ret = bcm_iproc_i2c_xfer_single_msg(iproc_i2c, &msgs[i]);
+		if (ret) {
+			dev_dbg(iproc_i2c->device, "xfer failed\n");
+			return ret;
+		}
+	}
+
+	return num;
+}
+
+static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm bcm_iproc_algo = {
+	.master_xfer = bcm_iproc_i2c_xfer,
+	.functionality = bcm_iproc_i2c_functionality,
+};
+
+static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
+{
+	unsigned int bus_speed;
+	u32 val;
+	int ret = of_property_read_u32(iproc_i2c->device->of_node,
+				       "clock-frequency", &bus_speed);
+	if (ret < 0) {
+		dev_info(iproc_i2c->device,
+			"unable to interpret clock-frequency DT property\n");
+		bus_speed = 100000;
+	}
+
+	if (bus_speed < 100000) {
+		dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n",
+			bus_speed);
+		dev_err(iproc_i2c->device,
+			"valid speeds are 100khz and 400khz\n");
+		return -EINVAL;
+	} else if (bus_speed < 400000) {
+		bus_speed = 100000;
+	} else {
+		bus_speed = 400000;
+	}
+
+	val = readl(iproc_i2c->base + TIM_CFG_OFFSET);
+	val &= ~(1 << TIM_CFG_MODE_400_SHIFT);
+	val |= (bus_speed == 400000) << TIM_CFG_MODE_400_SHIFT;
+	writel(val, iproc_i2c->base + TIM_CFG_OFFSET);
+
+	dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed);
+
+	return 0;
+}
+
+static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
+{
+	u32 val;
+
+	/* put controller in reset */
+	val = readl(iproc_i2c->base + CFG_OFFSET);
+	val |= 1 << CFG_RESET_SHIFT;
+	val &= ~(1 << CFG_EN_SHIFT);
+	writel(val, iproc_i2c->base + CFG_OFFSET);
+
+	/* wait 100 usec per spec */
+	udelay(100);
+
+	/* bring controller out of reset */
+	val &= ~(1 << CFG_RESET_SHIFT);
+	writel(val, iproc_i2c->base + CFG_OFFSET);
+
+	/* flush TX/RX FIFOs and set RX FIFO threshold to zero */
+	val = (1 << M_FIFO_RX_FLUSH_SHIFT) | (1 << M_FIFO_TX_FLUSH_SHIFT);
+	writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET);
+
+	/* disable all interrupts */
+	writel(0, iproc_i2c->base + IE_OFFSET);
+
+	/* clear all pending interrupts */
+	writel(0xffffffff, iproc_i2c->base + IS_OFFSET);
+
+	return 0;
+}
+
+static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
+					 bool enable)
+{
+	u32 val;
+
+	val = readl(iproc_i2c->base + CFG_OFFSET);
+	if (enable)
+		val |= BIT(CFG_EN_SHIFT);
+	else
+		val &= ~BIT(CFG_EN_SHIFT);
+	writel(val, iproc_i2c->base + CFG_OFFSET);
+}
+
+static int bcm_iproc_i2c_probe(struct platform_device *pdev)
+{
+	int irq, ret = 0;
+	struct bcm_iproc_i2c_dev *iproc_i2c;
+	struct i2c_adapter *adap;
+	struct resource *res;
+
+	iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c),
+				 GFP_KERNEL);
+	if (!iproc_i2c)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, iproc_i2c);
+	iproc_i2c->device = &pdev->dev;
+	init_completion(&iproc_i2c->done);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res);
+	if (IS_ERR(iproc_i2c->base))
+		return PTR_ERR(iproc_i2c->base);
+
+	ret = bcm_iproc_i2c_init(iproc_i2c);
+	if (ret)
+		return ret;
+
+	ret = bcm_iproc_i2c_cfg_speed(iproc_i2c);
+	if (ret)
+		return ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(iproc_i2c->device, "no irq resource\n");
+		return irq;
+	}
+	iproc_i2c->irq = irq;
+
+	ret = devm_request_irq(iproc_i2c->device, irq, bcm_iproc_i2c_isr, 0,
+			       pdev->name, iproc_i2c);
+	if (ret < 0) {
+		dev_err(iproc_i2c->device, "unable to request irq %i\n", irq);
+		return ret;
+	}
+
+	bcm_iproc_i2c_enable_disable(iproc_i2c, true);
+
+	adap = &iproc_i2c->adapter;
+	i2c_set_adapdata(adap, iproc_i2c);
+	strlcpy(adap->name, "Broadcom iProc I2C adapter", sizeof(adap->name));
+	adap->algo = &bcm_iproc_algo;
+	adap->dev.parent = &pdev->dev;
+	adap->dev.of_node = pdev->dev.of_node;
+
+	ret = i2c_add_adapter(adap);
+	if (ret) {
+		dev_err(iproc_i2c->device, "failed to add adapter\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bcm_iproc_i2c_remove(struct platform_device *pdev)
+{
+	struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
+
+	/* make sure there's no pending interrupt when we remove the adapter */
+	writel(0, iproc_i2c->base + IE_OFFSET);
+	readl(iproc_i2c->base + IE_OFFSET);
+	synchronize_irq(iproc_i2c->irq);
+
+	i2c_del_adapter(&iproc_i2c->adapter);
+	bcm_iproc_i2c_enable_disable(iproc_i2c, false);
+
+	return 0;
+}
+
+static const struct of_device_id bcm_iproc_i2c_of_match[] = {
+	{ .compatible = "brcm,iproc-i2c" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match);
+
+static struct platform_driver bcm_iproc_i2c_driver = {
+	.driver = {
+		.name = "bcm-iproc-i2c",
+		.of_match_table = bcm_iproc_i2c_of_match,
+	},
+	.probe = bcm_iproc_i2c_probe,
+	.remove = bcm_iproc_i2c_remove,
+};
+module_platform_driver(bcm_iproc_i2c_driver);
+
+MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom iProc I2C Driver");
+MODULE_LICENSE("GPL v2");

drivers/i2c/busses/i2c-cadence.c

@@ -128,6 +128,7 @@
  * @suspended:		Flag holding the device's PM status
  * @send_count:		Number of bytes still expected to send
  * @recv_count:		Number of bytes still expected to receive
+ * @curr_recv_count:	Number of bytes to be received in current transfer
  * @irq:		IRQ number
  * @input_clk:		Input clock to I2C controller
  * @i2c_clk:		Maximum I2C clock speed
@@ -146,6 +147,7 @@ struct cdns_i2c {
 	u8 suspended;
 	unsigned int send_count;
 	unsigned int recv_count;
+	unsigned int curr_recv_count;
 	int irq;
 	unsigned long input_clk;
 	unsigned int i2c_clk;
@@ -182,14 +184,15 @@ static void cdns_i2c_clear_bus_hold(struct cdns_i2c *id)
  */
 static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
 {
-	unsigned int isr_status, avail_bytes;
-	unsigned int bytes_to_recv, bytes_to_send;
+	unsigned int isr_status, avail_bytes, updatetx;
+	unsigned int bytes_to_send;
 	struct cdns_i2c *id = ptr;
 	/* Signal completion only after everything is updated */
 	int done_flag = 0;
 	irqreturn_t status = IRQ_NONE;
 
 	isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
+	cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
 
 	/* Handling nack and arbitration lost interrupt */
 	if (isr_status & (CDNS_I2C_IXR_NACK | CDNS_I2C_IXR_ARB_LOST)) {
@@ -197,47 +200,87 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
 		status = IRQ_HANDLED;
 	}
 
-	/* Handling Data interrupt */
-	if ((isr_status & CDNS_I2C_IXR_DATA) &&
-			(id->recv_count >= CDNS_I2C_DATA_INTR_DEPTH)) {
-		/* Always read data interrupt threshold bytes */
-		bytes_to_recv = CDNS_I2C_DATA_INTR_DEPTH;
-		id->recv_count -= CDNS_I2C_DATA_INTR_DEPTH;
-		avail_bytes = cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET);
+	/*
+	 * Check if transfer size register needs to be updated again for a
+	 * large data receive operation.
+	 */
+	updatetx = 0;
+	if (id->recv_count > id->curr_recv_count)
+		updatetx = 1;
+
+	/* When receiving, handle data interrupt and completion interrupt */
+	if (id->p_recv_buf &&
+	    ((isr_status & CDNS_I2C_IXR_COMP) ||
+	     (isr_status & CDNS_I2C_IXR_DATA))) {
+		/* Read data if receive data valid is set */
+		while (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) &
+		       CDNS_I2C_SR_RXDV) {
+			/*
+			 * Clear hold bit that was set for FIFO control if
+			 * RX data left is less than FIFO depth, unless
+			 * repeated start is selected.
+			 */
+			if ((id->recv_count < CDNS_I2C_FIFO_DEPTH) &&
+			    !id->bus_hold_flag)
+				cdns_i2c_clear_bus_hold(id);
+
+			*(id->p_recv_buf)++ =
+				cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET);
+			id->recv_count--;
+			id->curr_recv_count--;
+
+			if (updatetx &&
+			    (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1))
+				break;
+		}
+
+		/*
+		 * The controller sends NACK to the slave when transfer size
+		 * register reaches zero without considering the HOLD bit.
+		 * This workaround is implemented for large data transfers to
+		 * maintain transfer size non-zero while performing a large
+		 * receive operation.
+		 */
+		if (updatetx &&
+		    (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1)) {
+			/* wait while fifo is full */
+			while (cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET) !=
+			       (id->curr_recv_count - CDNS_I2C_FIFO_DEPTH))
+				;
 
 			/*
-		 * if the tranfer size register value is zero, then
-		 * check for the remaining bytes and update the
-		 * transfer size register.
+			 * Check number of bytes to be received against maximum
+			 * transfer size and update register accordingly.
 			 */
-		if (!avail_bytes) {
-			if (id->recv_count > CDNS_I2C_TRANSFER_SIZE)
+			if (((int)(id->recv_count) - CDNS_I2C_FIFO_DEPTH) >
+			    CDNS_I2C_TRANSFER_SIZE) {
 				cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE,
 						  CDNS_I2C_XFER_SIZE_OFFSET);
-			else
-				cdns_i2c_writereg(id->recv_count,
+				id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE +
+						      CDNS_I2C_FIFO_DEPTH;
+			} else {
+				cdns_i2c_writereg(id->recv_count -
+						  CDNS_I2C_FIFO_DEPTH,
 						  CDNS_I2C_XFER_SIZE_OFFSET);
+				id->curr_recv_count = id->recv_count;
+			}
 		}
 
-		/* Process the data received */
-		while (bytes_to_recv--)
-			*(id->p_recv_buf)++ =
-				cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET);
-
-		if (!id->bus_hold_flag &&
-				(id->recv_count <= CDNS_I2C_FIFO_DEPTH))
+		/* Clear hold (if not repeated start) and signal completion */
+		if ((isr_status & CDNS_I2C_IXR_COMP) && !id->recv_count) {
+			if (!id->bus_hold_flag)
 				cdns_i2c_clear_bus_hold(id);
+			done_flag = 1;
+		}
 
 		status = IRQ_HANDLED;
 	}
 
-	/* Handling Transfer Complete interrupt */
-	if (isr_status & CDNS_I2C_IXR_COMP) {
-		if (!id->p_recv_buf) {
+	/* When sending, handle transfer complete interrupt */
+	if ((isr_status & CDNS_I2C_IXR_COMP) && !id->p_recv_buf) {
 		/*
-			 * If the device is sending data If there is further
-			 * data to be sent. Calculate the available space
-			 * in FIFO and fill the FIFO with that many bytes.
+		 * If there is more data to be sent, calculate the
+		 * space available in FIFO and fill with that many bytes.
 		 */
 		if (id->send_count) {
 			avail_bytes = CDNS_I2C_FIFO_DEPTH -
@@ -263,23 +306,6 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
 		}
 		if (!id->send_count && !id->bus_hold_flag)
 			cdns_i2c_clear_bus_hold(id);
-		} else {
-			if (!id->bus_hold_flag)
-				cdns_i2c_clear_bus_hold(id);
-			/*
-			 * If the device is receiving data, then signal
-			 * the completion of transaction and read the data
-			 * present in the FIFO. Signal the completion of
-			 * transaction.
-			 */
-			while (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) &
-					CDNS_I2C_SR_RXDV) {
-				*(id->p_recv_buf)++ =
-					cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET);
-				id->recv_count--;
-			}
-			done_flag = 1;
-		}
 
 		status = IRQ_HANDLED;
 	}
@@ -289,8 +315,6 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
 	if (id->err_status)
 		status = IRQ_HANDLED;
 
-	cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
-
 	if (done_flag)
 		complete(&id->xfer_done);
 
@@ -316,6 +340,8 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
 	if (id->p_msg->flags & I2C_M_RECV_LEN)
 		id->recv_count = I2C_SMBUS_BLOCK_MAX + 1;
 
+	id->curr_recv_count = id->recv_count;
+
 	/*
 	 * Check for the message size against FIFO depth and set the
 	 * 'hold bus' bit if it is greater than FIFO depth.
@@ -335,11 +361,14 @@ static void cdns_i2c_mrecv(struct cdns_i2c *id)
 	 * receive if it is less than transfer size and transfer size if
 	 * it is more. Enable the interrupts.
 	 */
-	if (id->recv_count > CDNS_I2C_TRANSFER_SIZE)
+	if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) {
 		cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE,
 				  CDNS_I2C_XFER_SIZE_OFFSET);
-	else
+		id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE;
+	} else {
 		cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_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) &&
@@ -516,6 +545,20 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	 * processed with a repeated start.
 	 */
 	if (num > 1) {
+		/*
+		 * This controller does not give completion interrupt after a
+		 * master receive message if HOLD bit is set (repeated start),
+		 * resulting in SW timeout. Hence, if a receive message is
+		 * followed by any other message, an error is returned
+		 * indicating that this sequence is not supported.
+		 */
+		for (count = 0; count < num - 1; count++) {
+			if (msgs[count].flags & I2C_M_RD) {
+				dev_warn(adap->dev.parent,
+					 "Can't do repeated start after a receive message\n");
+				return -EOPNOTSUPP;
+			}
+		}
 		id->bus_hold_flag = 1;
 		reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
 		reg |= CDNS_I2C_CR_HOLD;

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

+/*
+ * Intel BayTrail PMIC I2C bus semaphore implementaion
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/module.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <asm/iosf_mbi.h>
+#include "i2c-designware-core.h"
+
+#define SEMAPHORE_TIMEOUT	100
+#define PUNIT_SEMAPHORE		0x7
+
+static unsigned long acquired;
+
+static int get_sem(struct device *dev, u32 *sem)
+{
+	u32 reg_val;
+	int ret;
+
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ, PUNIT_SEMAPHORE,
+			    &reg_val);
+	if (ret) {
+		dev_err(dev, "iosf failed to read punit semaphore\n");
+		return ret;
+	}
+
+	*sem = reg_val & 0x1;
+
+	return 0;
+}
+
+static void reset_semaphore(struct device *dev)
+{
+	u32 data;
+
+	if (iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+				PUNIT_SEMAPHORE, &data)) {
+		dev_err(dev, "iosf failed to reset punit semaphore during read\n");
+		return;
+	}
+
+	data = data & 0xfffffffe;
+	if (iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+				 PUNIT_SEMAPHORE, data))
+		dev_err(dev, "iosf failed to reset punit semaphore during write\n");
+}
+
+int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
+{
+	u32 sem = 0;
+	int ret;
+	unsigned long start, end;
+
+	if (!dev || !dev->dev)
+		return -ENODEV;
+
+	if (!dev->acquire_lock)
+		return 0;
+
+	/* host driver writes 0x2 to side band semaphore register */
+	ret = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE,
+				 PUNIT_SEMAPHORE, 0x2);
+	if (ret) {
+		dev_err(dev->dev, "iosf punit semaphore request failed\n");
+		return ret;
+	}
+
+	/* host driver waits for bit 0 to be set in semaphore register */
+	start = jiffies;
+	end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT);
+	while (!time_after(jiffies, end)) {
+		ret = get_sem(dev->dev, &sem);
+		if (!ret && sem) {
+			acquired = jiffies;
+			dev_dbg(dev->dev, "punit semaphore acquired after %ums\n",
+				jiffies_to_msecs(jiffies - start));
+			return 0;
+		}
+
+		usleep_range(1000, 2000);
+	}
+
+	dev_err(dev->dev, "punit semaphore timed out, resetting\n");
+	reset_semaphore(dev->dev);
+
+	ret = iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_READ,
+		PUNIT_SEMAPHORE, &sem);
+	if (!ret)
+		dev_err(dev->dev, "iosf failed to read punit semaphore\n");
+	else
+		dev_err(dev->dev, "PUNIT SEM: %d\n", sem);
+
+	WARN_ON(1);
+
+	return -ETIMEDOUT;
+}
+EXPORT_SYMBOL(baytrail_i2c_acquire);
+
+void baytrail_i2c_release(struct dw_i2c_dev *dev)
+{
+	if (!dev || !dev->dev)
+		return;
+
+	if (!dev->acquire_lock)
+		return;
+
+	reset_semaphore(dev->dev);
+	dev_dbg(dev->dev, "punit semaphore held for %ums\n",
+		jiffies_to_msecs(jiffies - acquired));
+}
+EXPORT_SYMBOL(baytrail_i2c_release);
+
+int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev)
+{
+	acpi_status status;
+	unsigned long long shared_host = 0;
+	acpi_handle handle;
+
+	if (!dev || !dev->dev)
+		return 0;
+
+	handle = ACPI_HANDLE(dev->dev);
+	if (!handle)
+		return 0;
+
+	status = acpi_evaluate_integer(handle, "_SEM", NULL, &shared_host);
+
+	if (ACPI_FAILURE(status))
+		return 0;
+
+	if (shared_host) {
+		dev_info(dev->dev, "I2C bus managed by PUNIT\n");
+		dev->acquire_lock = baytrail_i2c_acquire;
+		dev->release_lock = baytrail_i2c_release;
+		dev->pm_runtime_disabled = true;
+	}
+
+	if (!iosf_mbi_available())
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+EXPORT_SYMBOL(i2c_dw_eval_lock_support);
+
+MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
+MODULE_DESCRIPTION("Baytrail I2C Semaphore driver");
+MODULE_LICENSE("GPL v2");

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

@@ -170,10 +170,10 @@ u32 dw_readl(struct dw_i2c_dev *dev, int offset)
 	u32 value;
 
 	if (dev->accessor_flags & ACCESS_16BIT)
-		value = readw(dev->base + offset) |
-			(readw(dev->base + offset + 2) << 16);
+		value = readw_relaxed(dev->base + offset) |
+			(readw_relaxed(dev->base + offset + 2) << 16);
 	else
-		value = readl(dev->base + offset);
+		value = readl_relaxed(dev->base + offset);
 
 	if (dev->accessor_flags & ACCESS_SWAP)
 		return swab32(value);
@@ -187,10 +187,10 @@ void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
 		b = swab32(b);
 
 	if (dev->accessor_flags & ACCESS_16BIT) {
-		writew((u16)b, dev->base + offset);
-		writew((u16)(b >> 16), dev->base + offset + 2);
+		writew_relaxed((u16)b, dev->base + offset);
+		writew_relaxed((u16)(b >> 16), dev->base + offset + 2);
 	} else {
-		writel(b, dev->base + offset);
+		writel_relaxed(b, dev->base + offset);
 	}
 }
 
@@ -285,6 +285,15 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 	u32 hcnt, lcnt;
 	u32 reg;
 	u32 sda_falling_time, scl_falling_time;
+	int ret;
+
+	if (dev->acquire_lock) {
+		ret = dev->acquire_lock(dev);
+		if (ret) {
+			dev_err(dev->dev, "couldn't acquire bus ownership\n");
+			return ret;
+		}
+	}
 
 	input_clock_khz = dev->get_clk_rate_khz(dev);
 
@@ -298,6 +307,8 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
 		dev_err(dev->dev, "Unknown Synopsys component type: "
 			"0x%08x\n", reg);
+		if (dev->release_lock)
+			dev->release_lock(dev);
 		return -ENODEV;
 	}
 
@@ -309,7 +320,11 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 	sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
 	scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
 
-	/* Standard-mode */
+	/* Set SCL timing parameters for standard-mode */
+	if (dev->ss_hcnt && dev->ss_lcnt) {
+		hcnt = dev->ss_hcnt;
+		lcnt = dev->ss_lcnt;
+	} else {
 		hcnt = i2c_dw_scl_hcnt(input_clock_khz,
 					4000,	/* tHD;STA = tHIGH = 4.0 us */
 					sda_falling_time,
@@ -319,17 +334,16 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 					4700,	/* tLOW = 4.7 us */
 					scl_falling_time,
 					0);	/* No offset */
-
-	/* Allow platforms to specify the ideal HCNT and LCNT values */
-	if (dev->ss_hcnt && dev->ss_lcnt) {
-		hcnt = dev->ss_hcnt;
-		lcnt = dev->ss_lcnt;
 	}
 	dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
 	dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
 	dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
 
-	/* Fast-mode */
+	/* Set SCL timing parameters for fast-mode */
+	if (dev->fs_hcnt && dev->fs_lcnt) {
+		hcnt = dev->fs_hcnt;
+		lcnt = dev->fs_lcnt;
+	} else {
 		hcnt = i2c_dw_scl_hcnt(input_clock_khz,
 					600,	/* tHD;STA = tHIGH = 0.6 us */
 					sda_falling_time,
@@ -339,10 +353,6 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 					1300,	/* tLOW = 1.3 us */
 					scl_falling_time,
 					0);	/* No offset */
-
-	if (dev->fs_hcnt && dev->fs_lcnt) {
-		hcnt = dev->fs_hcnt;
-		lcnt = dev->fs_lcnt;
 	}
 	dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
 	dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
@@ -364,6 +374,9 @@ int i2c_dw_init(struct dw_i2c_dev *dev)
 
 	/* configure the i2c master */
 	dw_writel(dev, dev->master_cfg , DW_IC_CON);
+
+	if (dev->release_lock)
+		dev->release_lock(dev);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(i2c_dw_init);
@@ -627,6 +640,14 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	dev->abort_source = 0;
 	dev->rx_outstanding = 0;
 
+	if (dev->acquire_lock) {
+		ret = dev->acquire_lock(dev);
+		if (ret) {
+			dev_err(dev->dev, "couldn't acquire bus ownership\n");
+			goto done_nolock;
+		}
+	}
+
 	ret = i2c_dw_wait_bus_not_busy(dev);
 	if (ret < 0)
 		goto done;
@@ -672,6 +693,10 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	ret = -EIO;
 
 done:
+	if (dev->release_lock)
+		dev->release_lock(dev);
+
+done_nolock:
 	pm_runtime_mark_last_busy(dev->dev);
 	pm_runtime_put_autosuspend(dev->dev);
 	mutex_unlock(&dev->lock);

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

@@ -61,6 +61,9 @@
  * @ss_lcnt: standard speed LCNT value
  * @fs_hcnt: fast speed HCNT value
  * @fs_lcnt: fast speed LCNT value
+ * @acquire_lock: function to acquire a hardware lock on the bus
+ * @release_lock: function to release a hardware lock on the bus
+ * @pm_runtime_disabled: true if pm runtime is disabled
  *
  * 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.
@@ -101,6 +104,9 @@ struct dw_i2c_dev {
 	u16			ss_lcnt;
 	u16			fs_hcnt;
 	u16			fs_lcnt;
+	int			(*acquire_lock)(struct dw_i2c_dev *dev);
+	void			(*release_lock)(struct dw_i2c_dev *dev);
+	bool			pm_runtime_disabled;
 };
 
 #define ACCESS_SWAP		0x00000001
@@ -119,3 +125,9 @@ extern void i2c_dw_disable(struct dw_i2c_dev *dev);
 extern void i2c_dw_clear_int(struct dw_i2c_dev *dev);
 extern void i2c_dw_disable_int(struct dw_i2c_dev *dev);
 extern u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev);
+
+#if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL)
+extern int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev);
+#else
+static inline int i2c_dw_eval_lock_support(struct dw_i2c_dev *dev) { return 0; }
+#endif

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

@@ -6,7 +6,7 @@
  * Copyright (C) 2006 Texas Instruments.
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
- * Copyright (C) 2011 Intel corporation.
+ * Copyright (C) 2011, 2015 Intel Corporation.
  *
  * ----------------------------------------------------------------------------
  *
@@ -40,10 +40,6 @@
 #define DRIVER_NAME "i2c-designware-pci"
 
 enum dw_pci_ctl_id_t {
-	moorestown_0,
-	moorestown_1,
-	moorestown_2,
-
 	medfield_0,
 	medfield_1,
 	medfield_2,
@@ -102,27 +98,6 @@ static struct dw_scl_sda_cfg hsw_config = {
 };
 
 static struct dw_pci_controller dw_pci_controllers[] = {
-	[moorestown_0] = {
-		.bus_num     = 0,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
-	[moorestown_1] = {
-		.bus_num     = 1,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
-	[moorestown_2] = {
-		.bus_num     = 2,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
 	[medfield_0] = {
 		.bus_num     = 0,
 		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
@@ -170,7 +145,6 @@ static struct  dw_pci_controller  dw_pci_controllers[] = {
 		.bus_cfg = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
 		.tx_fifo_depth = 32,
 		.rx_fifo_depth = 32,
-		.clk_khz = 100000,
 		.functionality = I2C_FUNC_10BIT_ADDR,
 		.scl_sda_cfg = &byt_config,
 	},
@@ -179,7 +153,6 @@ static struct  dw_pci_controller  dw_pci_controllers[] = {
 		.bus_cfg = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
 		.tx_fifo_depth = 32,
 		.rx_fifo_depth = 32,
-		.clk_khz = 100000,
 		.functionality = I2C_FUNC_10BIT_ADDR,
 		.scl_sda_cfg = &hsw_config,
 	},
@@ -325,12 +298,8 @@ static void i2c_dw_pci_remove(struct pci_dev *pdev)
 MODULE_ALIAS("i2c_designware-pci");
 
 static const struct pci_device_id i2_designware_pci_ids[] = {
-	/* Moorestown */
-	{ PCI_VDEVICE(INTEL, 0x0802), moorestown_0 },
-	{ PCI_VDEVICE(INTEL, 0x0803), moorestown_1 },
-	{ PCI_VDEVICE(INTEL, 0x0804), moorestown_2 },
 	/* Medfield */
-	{ PCI_VDEVICE(INTEL, 0x0817), medfield_3,},
+	{ PCI_VDEVICE(INTEL, 0x0817), medfield_3 },
 	{ PCI_VDEVICE(INTEL, 0x0818), medfield_4 },
 	{ PCI_VDEVICE(INTEL, 0x0819), medfield_5 },
 	{ PCI_VDEVICE(INTEL, 0x082C), medfield_0 },
@@ -348,7 +317,7 @@ static const struct pci_device_id i2_designware_pci_ids[] = {
 	{ PCI_VDEVICE(INTEL, 0x9c61), haswell },
 	{ PCI_VDEVICE(INTEL, 0x9c62), haswell },
 	/* Braswell / Cherrytrail */
-	{ PCI_VDEVICE(INTEL, 0x22C1), baytrail,},
+	{ PCI_VDEVICE(INTEL, 0x22C1), baytrail },
 	{ PCI_VDEVICE(INTEL, 0x22C2), baytrail },
 	{ PCI_VDEVICE(INTEL, 0x22C3), baytrail },
 	{ PCI_VDEVICE(INTEL, 0x22C4), baytrail },

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

@@ -195,6 +195,10 @@ static int dw_i2c_probe(struct platform_device *pdev)
 			clk_freq = pdata->i2c_scl_freq;
 	}
 
+	r = i2c_dw_eval_lock_support(dev);
+	if (r)
+		return r;
+
 	dev->functionality =
 		I2C_FUNC_I2C |
 		I2C_FUNC_10BIT_ADDR |
@@ -257,10 +261,14 @@ static int dw_i2c_probe(struct platform_device *pdev)
 		return r;
 	}
 
+	if (dev->pm_runtime_disabled) {
+		pm_runtime_forbid(&pdev->dev);
+	} else {
 		pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
 		pm_runtime_use_autosuspend(&pdev->dev);
 		pm_runtime_set_active(&pdev->dev);
 		pm_runtime_enable(&pdev->dev);
+	}
 
 	return 0;
 }
@@ -310,6 +318,8 @@ static int dw_i2c_resume(struct device *dev)
 	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
 
 	clk_prepare_enable(i_dev->clk);
+
+	if (!i_dev->pm_runtime_disabled)
 		i2c_dw_init(i_dev);
 
 	return 0;

drivers/i2c/busses/i2c-imx.c

@@ -295,7 +295,6 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
 	dma->chan_tx = dma_request_slave_channel(dev, "tx");
 	if (!dma->chan_tx) {
 		dev_dbg(dev, "can't request DMA tx channel\n");
-		ret = -ENODEV;
 		goto fail_al;
 	}
 
@@ -313,7 +312,6 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
 	dma->chan_rx = dma_request_slave_channel(dev, "rx");
 	if (!dma->chan_rx) {
 		dev_dbg(dev, "can't request DMA rx channel\n");
-		ret = -ENODEV;
 		goto fail_tx;
 	}
 
@@ -481,7 +479,7 @@ static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx)
 	i2c_clk_rate = clk_get_rate(i2c_imx->clk);
 	if (i2c_imx->cur_clk == i2c_clk_rate)
 		return;
-	else
+
 	i2c_imx->cur_clk = i2c_clk_rate;
 
 	div = (i2c_clk_rate + i2c_imx->bitrate - 1) / i2c_imx->bitrate;
@@ -490,7 +488,8 @@ static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx)
 	else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div)
 		i = i2c_imx->hwdata->ndivs - 1;
 	else
-		for (i = 0; i2c_clk_div[i].div < div; i++);
+		for (i = 0; i2c_clk_div[i].div < div; i++)
+			;
 
 	/* Store divider value */
 	i2c_imx->ifdr = i2c_clk_div[i].val;
@@ -628,9 +627,9 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
 	result = wait_for_completion_timeout(
 				&i2c_imx->dma->cmd_complete,
 				msecs_to_jiffies(DMA_TIMEOUT));
-	if (result <= 0) {
+	if (result == 0) {
 		dmaengine_terminate_all(dma->chan_using);
-		return result ?: -ETIMEDOUT;
+		return -ETIMEDOUT;
 	}
 
 	/* Waiting for transfer complete. */
@@ -686,9 +685,9 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
 	result = wait_for_completion_timeout(
 				&i2c_imx->dma->cmd_complete,
 				msecs_to_jiffies(DMA_TIMEOUT));
-	if (result <= 0) {
+	if (result == 0) {
 		dmaengine_terminate_all(dma->chan_using);
-		return result ?: -ETIMEDOUT;
+		return -ETIMEDOUT;
 	}
 
 	/* waiting for transfer complete. */
@@ -822,6 +821,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
 	/* read data */
 	for (i = 0; i < msgs->len; i++) {
 		u8 len = 0;
+
 		result = i2c_imx_trx_complete(i2c_imx);
 		if (result)
 			return result;
@@ -917,15 +917,16 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
 		/* write/read data */
 #ifdef CONFIG_I2C_DEBUG_BUS
 		temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
-		dev_dbg(&i2c_imx->adapter.dev, "<%s> CONTROL: IEN=%d, IIEN=%d, "
-			"MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", __func__,
+		dev_dbg(&i2c_imx->adapter.dev,
+			"<%s> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
+			__func__,
 			(temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 			(temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 			(temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 		temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 		dev_dbg(&i2c_imx->adapter.dev,
-			"<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, "
-			"IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", __func__,
+			"<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
+			__func__,
 			(temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 			(temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 			(temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
@@ -1063,7 +1064,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
 		i2c_imx->adapter.name);
 	dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
 
-	/* Init DMA config if support*/
+	/* Init DMA config if supported */
 	i2c_imx_dma_request(i2c_imx, phy_addr);
 
 	return 0;   /* Return OK */

drivers/i2c/busses/i2c-ocores.c

@@ -12,6 +12,7 @@
  * kind, whether express or implied.
  */
 
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -35,7 +36,9 @@ struct ocores_i2c {
 	int pos;
 	int nmsgs;
 	int state; /* see STATE_ */
-	int clock_khz;
+	struct clk *clk;
+	int ip_clock_khz;
+	int bus_clock_khz;
 	void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value);
 	u8 (*getreg)(struct ocores_i2c *i2c, int reg);
 };
@@ -215,21 +218,34 @@ static int ocores_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 		return -ETIMEDOUT;
 }
 
-static void ocores_init(struct ocores_i2c *i2c)
+static int ocores_init(struct device *dev, struct ocores_i2c *i2c)
 {
 	int prescale;
+	int diff;
 	u8 ctrl = oc_getreg(i2c, OCI2C_CONTROL);
 
 	/* make sure the device is disabled */
 	oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN));
 
-	prescale = (i2c->clock_khz / (5*100)) - 1;
+	prescale = (i2c->ip_clock_khz / (5 * i2c->bus_clock_khz)) - 1;
+	prescale = clamp(prescale, 0, 0xffff);
+
+	diff = i2c->ip_clock_khz / (5 * (prescale + 1)) - i2c->bus_clock_khz;
+	if (abs(diff) > i2c->bus_clock_khz / 10) {
+		dev_err(dev,
+			"Unsupported clock settings: core: %d KHz, bus: %d KHz\n",
+			i2c->ip_clock_khz, i2c->bus_clock_khz);
+		return -EINVAL;
+	}
+
 	oc_setreg(i2c, OCI2C_PRELOW, prescale & 0xff);
 	oc_setreg(i2c, OCI2C_PREHIGH, prescale >> 8);
 
 	/* Init the device */
 	oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_IACK);
 	oc_setreg(i2c, OCI2C_CONTROL, ctrl | OCI2C_CTRL_IEN | OCI2C_CTRL_EN);
+
+	return 0;
 }
 
 
@@ -304,6 +320,8 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
 	struct device_node *np = pdev->dev.of_node;
 	const struct of_device_id *match;
 	u32 val;
+	u32 clock_frequency;
+	bool clock_frequency_present;
 
 	if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) {
 		/* no 'reg-shift', check for deprecated 'regstep' */
@@ -319,12 +337,42 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
 		}
 	}
 
-	if (of_property_read_u32(np, "clock-frequency", &val)) {
+	clock_frequency_present = !of_property_read_u32(np, "clock-frequency",
+							&clock_frequency);
+	i2c->bus_clock_khz = 100;
+
+	i2c->clk = devm_clk_get(&pdev->dev, NULL);
+
+	if (!IS_ERR(i2c->clk)) {
+		int ret = clk_prepare_enable(i2c->clk);
+
+		if (ret) {
 			dev_err(&pdev->dev,
-			"Missing required parameter 'clock-frequency'\n");
+				"clk_prepare_enable failed: %d\n", ret);
+			return ret;
+		}
+		i2c->ip_clock_khz = clk_get_rate(i2c->clk) / 1000;
+		if (clock_frequency_present)
+			i2c->bus_clock_khz = clock_frequency / 1000;
+	}
+
+	if (i2c->ip_clock_khz == 0) {
+		if (of_property_read_u32(np, "opencores,ip-clock-frequency",
+						&val)) {
+			if (!clock_frequency_present) {
+				dev_err(&pdev->dev,
+					"Missing required parameter 'opencores,ip-clock-frequency'\n");
 				return -ENODEV;
 			}
-	i2c->clock_khz = val / 1000;
+			i2c->ip_clock_khz = clock_frequency / 1000;
+			dev_warn(&pdev->dev,
+				 "Deprecated usage of the 'clock-frequency' property, please update to 'opencores,ip-clock-frequency'\n");
+		} else {
+			i2c->ip_clock_khz = val / 1000;
+			if (clock_frequency_present)
+				i2c->bus_clock_khz = clock_frequency / 1000;
+		}
+	}
 
 	of_property_read_u32(pdev->dev.of_node, "reg-io-width",
 				&i2c->reg_io_width);
@@ -368,7 +416,8 @@ static int ocores_i2c_probe(struct platform_device *pdev)
 	if (pdata) {
 		i2c->reg_shift = pdata->reg_shift;
 		i2c->reg_io_width = pdata->reg_io_width;
-		i2c->clock_khz = pdata->clock_khz;
+		i2c->ip_clock_khz = pdata->clock_khz;
+		i2c->bus_clock_khz = 100;
 	} else {
 		ret = ocores_i2c_of_probe(pdev, i2c);
 		if (ret)
@@ -402,7 +451,9 @@ static int ocores_i2c_probe(struct platform_device *pdev)
 		}
 	}
 
-	ocores_init(i2c);
+	ret = ocores_init(&pdev->dev, i2c);
+	if (ret)
+		return ret;
 
 	init_waitqueue_head(&i2c->wait);
 	ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0,
@@ -446,6 +497,9 @@ static int ocores_i2c_remove(struct platform_device *pdev)
 	/* remove adapter & data */
 	i2c_del_adapter(&i2c->adap);
 
+	if (!IS_ERR(i2c->clk))
+		clk_disable_unprepare(i2c->clk);
+
 	return 0;
 }
 
@@ -458,6 +512,8 @@ static int ocores_i2c_suspend(struct device *dev)
 	/* make sure the device is disabled */
 	oc_setreg(i2c, OCI2C_CONTROL, ctrl & ~(OCI2C_CTRL_EN|OCI2C_CTRL_IEN));
 
+	if (!IS_ERR(i2c->clk))
+		clk_disable_unprepare(i2c->clk);
 	return 0;
 }
 
@@ -465,9 +521,20 @@ static int ocores_i2c_resume(struct device *dev)
 {
 	struct ocores_i2c *i2c = dev_get_drvdata(dev);
 
-	ocores_init(i2c);
+	if (!IS_ERR(i2c->clk)) {
+		unsigned long rate;
+		int ret = clk_prepare_enable(i2c->clk);
 
-	return 0;
+		if (ret) {
+			dev_err(dev,
+				"clk_prepare_enable failed: %d\n", ret);
+			return ret;
+		}
+		rate = clk_get_rate(i2c->clk) / 1000;
+		if (rate)
+			i2c->ip_clock_khz = rate;
+	}
+	return ocores_init(dev, i2c);
 }
 
 static SIMPLE_DEV_PM_OPS(ocores_i2c_pm, ocores_i2c_suspend, ocores_i2c_resume);

drivers/i2c/busses/i2c-pmcmsp.c

@@ -148,13 +148,6 @@ static inline u32 pmcmsptwi_clock_to_reg(
 	return ((clock->filter & 0xf) << 12) | (clock->clock & 0x03ff);
 }
 
-static inline void pmcmsptwi_reg_to_clock(
-			u32 reg, struct pmcmsptwi_clock *clock)
-{
-	clock->filter = (reg >> 12) & 0xf;
-	clock->clock = reg & 0x03ff;
-}
-
 static inline u32 pmcmsptwi_cfg_to_reg(const struct pmcmsptwi_cfg *cfg)
 {
 	return ((cfg->arbf & 0xf) << 12) |

drivers/i2c/busses/i2c-rk3x.c

@@ -102,6 +102,9 @@ struct rk3x_i2c {
 
 	/* Settings */
 	unsigned int scl_frequency;
+	unsigned int scl_rise_ns;
+	unsigned int scl_fall_ns;
+	unsigned int sda_fall_ns;
 
 	/* Synchronization & notification */
 	spinlock_t lock;
@@ -435,6 +438,9 @@ static irqreturn_t rk3x_i2c_irq(int irqno, void *dev_id)
  *
  * @clk_rate: I2C input clock rate
  * @scl_rate: Desired SCL rate
+ * @scl_rise_ns: How many ns it takes for SCL to rise.
+ * @scl_fall_ns: How many ns it takes for SCL to fall.
+ * @sda_fall_ns: How many ns it takes for SDA to fall.
  * @div_low: Divider output for low
  * @div_high: Divider output for high
  *
@@ -443,11 +449,16 @@ static irqreturn_t rk3x_i2c_irq(int irqno, void *dev_id)
  * too high, we silently use the highest possible rate.
  */
 static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
+			      unsigned long scl_rise_ns,
+			      unsigned long scl_fall_ns,
+			      unsigned long sda_fall_ns,
 			      unsigned long *div_low, unsigned long *div_high)
 {
-	unsigned long min_low_ns, min_high_ns;
-	unsigned long max_data_hold_ns;
+	unsigned long spec_min_low_ns, spec_min_high_ns;
+	unsigned long spec_setup_start, spec_max_data_hold_ns;
 	unsigned long data_hold_buffer_ns;
+
+	unsigned long min_low_ns, min_high_ns;
 	unsigned long max_low_ns, min_total_ns;
 
 	unsigned long clk_rate_khz, scl_rate_khz;
@@ -469,29 +480,50 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
 		scl_rate = 1000;
 
 	/*
-	 * min_low_ns:  The minimum number of ns we need to hold low
-	 *		to meet i2c spec
-	 * min_high_ns: The minimum number of ns we need to hold high
-	 *		to meet i2c spec
-	 * max_low_ns:  The maximum number of ns we can hold low
-	 *		to meet i2c spec
+	 * min_low_ns:  The minimum number of ns we need to hold low to
+	 *		meet I2C specification, should include fall time.
+	 * min_high_ns: The minimum number of ns we need to hold high to
+	 *		meet I2C specification, should include rise time.
+	 * max_low_ns:  The maximum number of ns we can hold low to meet
+	 *		I2C specification.
 	 *
-	 * Note: max_low_ns should be (max data hold time * 2 - buffer)
+	 * Note: max_low_ns should be (maximum data hold time * 2 - buffer)
 	 *	 This is because the i2c host on Rockchip holds the data line
 	 *	 for half the low time.
 	 */
 	if (scl_rate <= 100000) {
-		min_low_ns = 4700;
-		min_high_ns = 4000;
-		max_data_hold_ns = 3450;
+		/* Standard-mode */
+		spec_min_low_ns = 4700;
+		spec_setup_start = 4700;
+		spec_min_high_ns = 4000;
+		spec_max_data_hold_ns = 3450;
 		data_hold_buffer_ns = 50;
 	} else {
-		min_low_ns = 1300;
-		min_high_ns = 600;
-		max_data_hold_ns = 900;
+		/* Fast-mode */
+		spec_min_low_ns = 1300;
+		spec_setup_start = 600;
+		spec_min_high_ns = 600;
+		spec_max_data_hold_ns = 900;
 		data_hold_buffer_ns = 50;
 	}
-	max_low_ns = max_data_hold_ns * 2 - data_hold_buffer_ns;
+	min_high_ns = scl_rise_ns + spec_min_high_ns;
+
+	/*
+	 * Timings for repeated start:
+	 * - controller appears to drop SDA at .875x (7/8) programmed clk high.
+	 * - controller appears to keep SCL high for 2x programmed clk high.
+	 *
+	 * We need to account for those rules in picking our "high" time so
+	 * we meet tSU;STA and tHD;STA times.
+	 */
+	min_high_ns = max(min_high_ns,
+		DIV_ROUND_UP((scl_rise_ns + spec_setup_start) * 1000, 875));
+	min_high_ns = max(min_high_ns,
+		DIV_ROUND_UP((scl_rise_ns + spec_setup_start +
+			      sda_fall_ns + spec_min_high_ns), 2));
+
+	min_low_ns = scl_fall_ns + spec_min_low_ns;
+	max_low_ns = spec_max_data_hold_ns * 2 - data_hold_buffer_ns;
 	min_total_ns = min_low_ns + min_high_ns;
 
 	/* Adjust to avoid overflow */
@@ -510,8 +542,8 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
 	min_div_for_hold = (min_low_div + min_high_div);
 
 	/*
-	 * This is the maximum divider so we don't go over the max.
-	 * We don't round up here (we round down) since this is a max.
+	 * This is the maximum divider so we don't go over the maximum.
+	 * We don't round up here (we round down) since this is a maximum.
 	 */
 	max_low_div = clk_rate_khz * max_low_ns / (8 * 1000000);
 
@@ -544,7 +576,7 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
 		ideal_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns,
 					     scl_rate_khz * 8 * min_total_ns);
 
-		/* Don't allow it to go over the max */
+		/* Don't allow it to go over the maximum */
 		if (ideal_low_div > max_low_div)
 			ideal_low_div = max_low_div;
 
@@ -588,9 +620,9 @@ static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 	u64 t_low_ns, t_high_ns;
 	int ret;
 
-	ret = rk3x_i2c_calc_divs(clk_rate, i2c->scl_frequency, &div_low,
-				 &div_high);
-
+	ret = rk3x_i2c_calc_divs(clk_rate, i2c->scl_frequency, i2c->scl_rise_ns,
+				 i2c->scl_fall_ns, i2c->sda_fall_ns,
+				 &div_low, &div_high);
 	WARN_ONCE(ret != 0, "Could not reach SCL freq %u", i2c->scl_frequency);
 
 	clk_enable(i2c->clk);
@@ -633,9 +665,10 @@ static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
 	switch (event) {
 	case PRE_RATE_CHANGE:
 		if (rk3x_i2c_calc_divs(ndata->new_rate, i2c->scl_frequency,
-				      &div_low, &div_high) != 0) {
+				       i2c->scl_rise_ns, i2c->scl_fall_ns,
+				       i2c->sda_fall_ns,
+				       &div_low, &div_high) != 0)
 			return NOTIFY_STOP;
-		}
 
 		/* scale up */
 		if (ndata->new_rate > ndata->old_rate)
@@ -859,6 +892,24 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 		i2c->scl_frequency = DEFAULT_SCL_RATE;
 	}
 
+	/*
+	 * Read rise and fall time from device tree. If not available use
+	 * the default maximum timing from the specification.
+	 */
+	if (of_property_read_u32(pdev->dev.of_node, "i2c-scl-rising-time-ns",
+				 &i2c->scl_rise_ns)) {
+		if (i2c->scl_frequency <= 100000)
+			i2c->scl_rise_ns = 1000;
+		else
+			i2c->scl_rise_ns = 300;
+	}
+	if (of_property_read_u32(pdev->dev.of_node, "i2c-scl-falling-time-ns",
+				 &i2c->scl_fall_ns))
+		i2c->scl_fall_ns = 300;
+	if (of_property_read_u32(pdev->dev.of_node, "i2c-sda-falling-time-ns",
+				 &i2c->scl_fall_ns))
+		i2c->sda_fall_ns = i2c->scl_fall_ns;
+
 	strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name));
 	i2c->adap.owner = THIS_MODULE;
 	i2c->adap.algo = &rk3x_i2c_algorithm;

drivers/i2c/busses/i2c-tegra.c

@@ -286,6 +286,7 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
 	if (rx_fifo_avail > 0 && buf_remaining > 0) {
 		BUG_ON(buf_remaining > 3);
 		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
+		val = cpu_to_le32(val);
 		memcpy(buf, &val, buf_remaining);
 		buf_remaining = 0;
 		rx_fifo_avail--;
@@ -344,6 +345,7 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
 	if (tx_fifo_avail > 0 && buf_remaining > 0) {
 		BUG_ON(buf_remaining > 3);
 		memcpy(&val, buf, buf_remaining);
+		val = le32_to_cpu(val);
 
 		/* Again update before writing to FIFO to make sure isr sees. */
 		i2c_dev->msg_buf_remaining = 0;

drivers/i2c/i2c-core.c

@@ -102,7 +102,7 @@ static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data)
 		struct acpi_resource_i2c_serialbus *sb;
 
 		sb = &ares->data.i2c_serial_bus;
-		if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) {
+		if (!info->addr && sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) {
 			info->addr = sb->slave_address;
 			if (sb->access_mode == ACPI_I2C_10BIT_MODE)
 				info->flags |= I2C_CLIENT_TEN;
@@ -698,101 +698,6 @@ static void i2c_device_shutdown(struct device *dev)
 		driver->shutdown(client);
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg)
-{
-	struct i2c_client *client = i2c_verify_client(dev);
-	struct i2c_driver *driver;
-
-	if (!client || !dev->driver)
-		return 0;
-	driver = to_i2c_driver(dev->driver);
-	if (!driver->suspend)
-		return 0;
-	return driver->suspend(client, mesg);
-}
-
-static int i2c_legacy_resume(struct device *dev)
-{
-	struct i2c_client *client = i2c_verify_client(dev);
-	struct i2c_driver *driver;
-
-	if (!client || !dev->driver)
-		return 0;
-	driver = to_i2c_driver(dev->driver);
-	if (!driver->resume)
-		return 0;
-	return driver->resume(client);
-}
-
-static int i2c_device_pm_suspend(struct device *dev)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	if (pm)
-		return pm_generic_suspend(dev);
-	else
-		return i2c_legacy_suspend(dev, PMSG_SUSPEND);
-}
-
-static int i2c_device_pm_resume(struct device *dev)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	if (pm)
-		return pm_generic_resume(dev);
-	else
-		return i2c_legacy_resume(dev);
-}
-
-static int i2c_device_pm_freeze(struct device *dev)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	if (pm)
-		return pm_generic_freeze(dev);
-	else
-		return i2c_legacy_suspend(dev, PMSG_FREEZE);
-}
-
-static int i2c_device_pm_thaw(struct device *dev)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	if (pm)
-		return pm_generic_thaw(dev);
-	else
-		return i2c_legacy_resume(dev);
-}
-
-static int i2c_device_pm_poweroff(struct device *dev)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	if (pm)
-		return pm_generic_poweroff(dev);
-	else
-		return i2c_legacy_suspend(dev, PMSG_HIBERNATE);
-}
-
-static int i2c_device_pm_restore(struct device *dev)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	if (pm)
-		return pm_generic_restore(dev);
-	else
-		return i2c_legacy_resume(dev);
-}
-#else /* !CONFIG_PM_SLEEP */
-#define i2c_device_pm_suspend	NULL
-#define i2c_device_pm_resume	NULL
-#define i2c_device_pm_freeze	NULL
-#define i2c_device_pm_thaw	NULL
-#define i2c_device_pm_poweroff	NULL
-#define i2c_device_pm_restore	NULL
-#endif /* !CONFIG_PM_SLEEP */
-
 static void i2c_client_dev_release(struct device *dev)
 {
 	kfree(to_i2c_client(dev));
@@ -804,6 +709,7 @@ show_name(struct device *dev, struct device_attribute *attr, char *buf)
 	return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
 		       to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
 }
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 
 static ssize_t
 show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
@@ -817,8 +723,6 @@ show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 
 	return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
 }
-
-static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
 
 static struct attribute *i2c_dev_attrs[] = {
@@ -827,29 +731,7 @@ static struct attribute *i2c_dev_attrs[] = {
 	&dev_attr_modalias.attr,
 	NULL
 };
-
-static struct attribute_group i2c_dev_attr_group = {
-	.attrs		= i2c_dev_attrs,
-};
-
-static const struct attribute_group *i2c_dev_attr_groups[] = {
-	&i2c_dev_attr_group,
-	NULL
-};
-
-static const struct dev_pm_ops i2c_device_pm_ops = {
-	.suspend = i2c_device_pm_suspend,
-	.resume = i2c_device_pm_resume,
-	.freeze = i2c_device_pm_freeze,
-	.thaw = i2c_device_pm_thaw,
-	.poweroff = i2c_device_pm_poweroff,
-	.restore = i2c_device_pm_restore,
-	SET_RUNTIME_PM_OPS(
-		pm_generic_runtime_suspend,
-		pm_generic_runtime_resume,
-		NULL
-	)
-};
+ATTRIBUTE_GROUPS(i2c_dev);
 
 struct bus_type i2c_bus_type = {
 	.name		= "i2c",
@@ -857,12 +739,11 @@ struct bus_type i2c_bus_type = {
 	.probe		= i2c_device_probe,
 	.remove		= i2c_device_remove,
 	.shutdown	= i2c_device_shutdown,
-	.pm		= &i2c_device_pm_ops,
 };
 EXPORT_SYMBOL_GPL(i2c_bus_type);
 
 static struct device_type i2c_client_type = {
-	.groups		= i2c_dev_attr_groups,
+	.groups		= i2c_dev_groups,
 	.uevent		= i2c_device_uevent,
 	.release	= i2c_client_dev_release,
 };
@@ -1261,6 +1142,7 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
 
 	return count;
 }
+static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
 
 /*
  * And of course let the users delete the devices they instantiated, if
@@ -1315,8 +1197,6 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
 			"delete_device");
 	return res;
 }
-
-static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
 static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
 				   i2c_sysfs_delete_device);
 
@@ -1326,18 +1206,10 @@ static struct attribute *i2c_adapter_attrs[] = {
 	&dev_attr_delete_device.attr,
 	NULL
 };
-
-static struct attribute_group i2c_adapter_attr_group = {
-	.attrs		= i2c_adapter_attrs,
-};
-
-static const struct attribute_group *i2c_adapter_attr_groups[] = {
-	&i2c_adapter_attr_group,
-	NULL
-};
+ATTRIBUTE_GROUPS(i2c_adapter);
 
 struct device_type i2c_adapter_type = {
-	.groups		= i2c_adapter_attr_groups,
+	.groups		= i2c_adapter_groups,
 	.release	= i2c_adapter_dev_release,
 };
 EXPORT_SYMBOL_GPL(i2c_adapter_type);
@@ -1419,8 +1291,6 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
 	if (of_get_property(node, "wakeup-source", NULL))
 		info.flags |= I2C_CLIENT_WAKE;
 
-	request_module("%s%s", I2C_MODULE_PREFIX, info.type);
-
 	result = i2c_new_device(adap, &info);
 	if (result == NULL) {
 		dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
@@ -1796,11 +1666,15 @@ void i2c_del_adapter(struct i2c_adapter *adap)
 	/* device name is gone after device_unregister */
 	dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
 
-	/* clean up the sysfs representation */
+	/* wait until all references to the device are gone
+	 *
+	 * FIXME: This is old code and should ideally be replaced by an
+	 * alternative which results in decoupling the lifetime of the struct
+	 * device from the i2c_adapter, like spi or netdev do. Any solution
+	 * should be throughly tested with DEBUG_KOBJECT_RELEASE enabled!
+	 */
 	init_completion(&adap->dev_released);
 	device_unregister(&adap->dev);
-
-	/* wait for sysfs to drop all references */
 	wait_for_completion(&adap->dev_released);
 
 	/* free bus id */
@@ -1859,14 +1733,6 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
 	if (res)
 		return res;
 
-	/* Drivers should switch to dev_pm_ops instead. */
-	if (driver->suspend)
-		pr_warn("i2c-core: driver [%s] using legacy suspend method\n",
-			driver->driver.name);
-	if (driver->resume)
-		pr_warn("i2c-core: driver [%s] using legacy resume method\n",
-			driver->driver.name);
-
 	pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
 
 	INIT_LIST_HEAD(&driver->clients);

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

@@ -41,6 +41,7 @@
 #include <linux/i2c-mux.h>
 #include <linux/i2c/pca954x.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
 
@@ -186,6 +187,8 @@ static int pca954x_probe(struct i2c_client *client,
 {
 	struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
 	struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct device_node *of_node = client->dev.of_node;
+	bool idle_disconnect_dt;
 	struct gpio_desc *gpio;
 	int num, force, class;
 	struct pca954x *data;
@@ -217,8 +220,13 @@ static int pca954x_probe(struct i2c_client *client,
 	data->type = id->driver_data;
 	data->last_chan = 0;		   /* force the first selection */
 
+	idle_disconnect_dt = of_node &&
+		of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
+
 	/* Now create an adapter for each channel */
 	for (num = 0; num < chips[data->type].nchans; num++) {
+		bool idle_disconnect_pd = false;
+
 		force = 0;			  /* dynamic adap number */
 		class = 0;			  /* no class by default */
 		if (pdata) {
@@ -229,12 +237,13 @@ static int pca954x_probe(struct i2c_client *client,
 			} else
 				/* discard unconfigured channels */
 				break;
+			idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
 		}
 
 		data->virt_adaps[num] =
 			i2c_add_mux_adapter(adap, &client->dev, client,
 				force, num, class, pca954x_select_chan,
-				(pdata && pdata->modes[num].deselect_on_exit)
+				(idle_disconnect_pd || idle_disconnect_dt)
 					? pca954x_deselect_mux : NULL);
 
 		if (data->virt_adaps[num] == NULL) {

include/linux/i2c.h

@@ -130,8 +130,6 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
  * @probe: Callback for device binding
  * @remove: Callback for device unbinding
  * @shutdown: Callback for device shutdown
- * @suspend: Callback for device suspend
- * @resume: Callback for device resume
  * @alert: Alert callback, for example for the SMBus alert protocol
  * @command: Callback for bus-wide signaling (optional)
  * @driver: Device driver model driver
@@ -174,8 +172,6 @@ struct i2c_driver {
 
 	/* driver model interfaces that don't relate to enumeration  */
 	void (*shutdown)(struct i2c_client *);
-	int (*suspend)(struct i2c_client *, pm_message_t mesg);
-	int (*resume)(struct i2c_client *);
 
 	/* Alert callback, for example for the SMBus alert protocol.
 	 * The format and meaning of the data value depends on the protocol.