i2c-intel-mid: support for Moorestown and Medfield platform

(Updated to address Ben's comments. With regard to the message segment
 restriction it's not something we hit on the actual platform so while
 I will investigate that further I don't think its a blocker to submission.
 At worst its a spot over-restrictive)

From: Wen Wang <wen.w.wang@intel.com>

Initial release of the driver. Updated and verified on hardware.

Cleaned up as follows

Alan Cox:
   Squash down the switches into tables, and use the PCI ident field. We
   could perhaps take this further and put the platform and port number into
   this.
   uint32t -> u32
   bracketing of case statements
   spacing and '!' usage
   Check the speed (which is now 0/1/2) is valid and ignore otherwise.
   Fix remaining problems/suggestions from Jean's review
   Fix items from Ben's review

Arjan van de Ven:
   Initial power management hooks

Yong Wang <youg.y.wang@intel.com>:
   Shared IRQ support

Wen Wang <wen.w.wang@intel.com>:
   D3 support
   Fixes for OCT test runs
   Interrupt optimisations

Hong Liu <hong.liu@intel.com>
   The runtime PM code is working on the wrong device (i2c_adapter->dev).
   The correct one should be pci_dev->dev. This breaks attached i2c
   slave devices with runtime PM enabled. Slave device needs to runtime
   resume parent device before runtime resuming itself, but we always get
   error since we don't have pm_runtime callback for i2c_adapter->dev.

Bin Yang <bin.yang@intel.com>:
   Update speed table

Saadi Maalem <saadi.maalem@intel.com>:
   Clear all interrupts in the hardware init

Celine Chotard <celinex.chotard@intel.com>:
   Correct ordering of clear/disable of IRQs

Signed-off-by: Wen Wang <wen.w.wang@intel.com>
Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Signed-off-by: Hong Liu <hong.liu@intel.com>
Signed-off-by: Bin Yang <bin.yang@intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 1135 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-intel-mid.c b/drivers/i2c/busses/i2c-intel-mid.c
new file mode 100644
index 000000000000..80f70d3a744d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-intel-mid.c
@@ -0,0 +1,1135 @@
+/*
+ * Support for Moorestown/Medfield I2C chip
+ *
+ * Copyright (c) 2009 Intel Corporation.
+ * Copyright (c) 2009 Synopsys. Inc.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+#include <linux/io.h>
+
+#define DRIVER_NAME     "i2c-intel-mid"
+#define VERSION         "Version 0.5ac2"
+#define PLATFORM        "Moorestown/Medfield"
+
+/* Tables use: 0 Moorestown, 1 Medfield */
+#define NUM_PLATFORMS   2
+enum platform_enum {
+        MOORESTOWN = 0,
+        MEDFIELD = 1,
+};
+
+enum mid_i2c_status {
+        STATUS_IDLE = 0,
+        STATUS_READ_START,
+        STATUS_READ_IN_PROGRESS,
+        STATUS_READ_SUCCESS,
+        STATUS_WRITE_START,
+        STATUS_WRITE_SUCCESS,
+        STATUS_XFER_ABORT,
+        STATUS_STANDBY
+};
+
+/**
+ * struct intel_mid_i2c_private - per device I²C context
+ * @adap: core i2c layer adapter information
+ * @dev: device reference for power management
+ * @base: register base
+ * @speed: speed mode for this port
+ * @complete: completion object for transaction wait
+ * @abort: reason for last abort
+ * @rx_buf: pointer into working receive buffer
+ * @rx_buf_len: receive buffer length
+ * @status: adapter state machine
+ * @msg: the message we are currently processing
+ * @platform: the MID device type we are part of
+ * @lock: transaction serialization
+ *
+ * We allocate one of these per device we discover, it holds the core
+ * i2c layer objects and the data we need to track privately.
+ */
+struct intel_mid_i2c_private {
+        struct i2c_adapter adap;
+        struct device *dev;
+        void __iomem *base;
+        int speed;
+        struct completion complete;
+        int abort;
+        u8 *rx_buf;
+        int rx_buf_len;
+        enum mid_i2c_status status;
+        struct i2c_msg *msg;
+        enum platform_enum platform;
+        struct mutex lock;
+};
+
+#define NUM_SPEEDS              3
+
+#define ACTIVE                  0
+#define STANDBY                 1
+
+
+/* Control register */
+#define IC_CON                  0x00
+#define SLV_DIS                 (1 << 6)        /* Disable slave mode */
+#define RESTART                 (1 << 5)        /* Send a Restart condition */
+#define ADDR_10BIT              (1 << 4)        /* 10-bit addressing */
+#define STANDARD_MODE           (1 << 1)        /* standard mode */
+#define FAST_MODE               (2 << 1)        /* fast mode */
+#define HIGH_MODE               (3 << 1)        /* high speed mode */
+#define MASTER_EN               (1 << 0)        /* Master mode */
+
+/* Target address register */
+#define IC_TAR                  0x04
+#define IC_TAR_10BIT_ADDR       (1 << 12)       /* 10-bit addressing */
+#define IC_TAR_SPECIAL          (1 << 11)       /* Perform special I2C cmd */
+#define IC_TAR_GC_OR_START      (1 << 10)       /* 0: Gerneral Call Address */
+                                                /* 1: START BYTE */
+/* Slave Address Register */
+#define IC_SAR                  0x08            /* Not used in Master mode */
+
+/* High Speed Master Mode Code Address Register */
+#define IC_HS_MADDR             0x0c
+
+/* Rx/Tx Data Buffer and Command Register */
+#define IC_DATA_CMD             0x10
+#define IC_RD                   (1 << 8)        /* 1: Read 0: Write */
+
+/* Standard Speed Clock SCL High Count Register */
+#define IC_SS_SCL_HCNT          0x14
+
+/* Standard Speed Clock SCL Low Count Register */
+#define IC_SS_SCL_LCNT          0x18
+
+/* Fast Speed Clock SCL High Count Register */
+#define IC_FS_SCL_HCNT          0x1c
+
+/* Fast Spedd Clock SCL Low Count Register */
+#define IC_FS_SCL_LCNT          0x20
+
+/* High Speed Clock SCL High Count Register */
+#define IC_HS_SCL_HCNT          0x24
+
+/* High Speed Clock SCL Low Count Register */
+#define IC_HS_SCL_LCNT          0x28
+
+/* Interrupt Status Register */
+#define IC_INTR_STAT            0x2c            /* Read only */
+#define R_GEN_CALL              (1 << 11)
+#define R_START_DET             (1 << 10)
+#define R_STOP_DET              (1 << 9)
+#define R_ACTIVITY              (1 << 8)
+#define R_RX_DONE               (1 << 7)
+#define R_TX_ABRT               (1 << 6)
+#define R_RD_REQ                (1 << 5)
+#define R_TX_EMPTY              (1 << 4)
+#define R_TX_OVER               (1 << 3)
+#define R_RX_FULL               (1 << 2)
+#define R_RX_OVER               (1 << 1)
+#define R_RX_UNDER              (1 << 0)
+
+/* Interrupt Mask Register */
+#define IC_INTR_MASK            0x30            /* Read and Write */
+#define M_GEN_CALL              (1 << 11)
+#define M_START_DET             (1 << 10)
+#define M_STOP_DET              (1 << 9)
+#define M_ACTIVITY              (1 << 8)
+#define M_RX_DONE               (1 << 7)
+#define M_TX_ABRT               (1 << 6)
+#define M_RD_REQ                (1 << 5)
+#define M_TX_EMPTY              (1 << 4)
+#define M_TX_OVER               (1 << 3)
+#define M_RX_FULL               (1 << 2)
+#define M_RX_OVER               (1 << 1)
+#define M_RX_UNDER              (1 << 0)
+
+/* Raw Interrupt Status Register */
+#define IC_RAW_INTR_STAT        0x34            /* Read Only */
+#define GEN_CALL                (1 << 11)       /* General call */
+#define START_DET               (1 << 10)       /* (RE)START occured */
+#define STOP_DET                (1 << 9)        /* STOP occured */
+#define ACTIVITY                (1 << 8)        /* Bus busy */
+#define RX_DONE                 (1 << 7)        /* Not used in Master mode */
+#define TX_ABRT                 (1 << 6)        /* Transmit Abort */
+#define RD_REQ                  (1 << 5)        /* Not used in Master mode */
+#define TX_EMPTY                (1 << 4)        /* TX FIFO <= threshold */
+#define TX_OVER                 (1 << 3)        /* TX FIFO overflow */
+#define RX_FULL                 (1 << 2)        /* RX FIFO >= threshold */
+#define RX_OVER                 (1 << 1)        /* RX FIFO overflow */
+#define RX_UNDER                (1 << 0)        /* RX FIFO empty */
+
+/* Receive FIFO Threshold Register */
+#define IC_RX_TL                0x38
+
+/* Transmit FIFO Treshold Register */
+#define IC_TX_TL                0x3c
+
+/* Clear Combined and Individual Interrupt Register */
+#define IC_CLR_INTR             0x40
+#define CLR_INTR                (1 << 0)
+
+/* Clear RX_UNDER Interrupt Register */
+#define IC_CLR_RX_UNDER         0x44
+#define CLR_RX_UNDER            (1 << 0)
+
+/* Clear RX_OVER Interrupt Register */
+#define IC_CLR_RX_OVER          0x48
+#define CLR_RX_OVER             (1 << 0)
+
+/* Clear TX_OVER Interrupt Register */
+#define IC_CLR_TX_OVER          0x4c
+#define CLR_TX_OVER             (1 << 0)
+
+#define IC_CLR_RD_REQ           0x50
+
+/* Clear TX_ABRT Interrupt Register */
+#define IC_CLR_TX_ABRT          0x54
+#define CLR_TX_ABRT             (1 << 0)
+#define IC_CLR_RX_DONE          0x58
+
+/* Clear ACTIVITY Interrupt Register */
+#define IC_CLR_ACTIVITY         0x5c
+#define CLR_ACTIVITY            (1 << 0)
+
+/* Clear STOP_DET Interrupt Register */
+#define IC_CLR_STOP_DET         0x60
+#define CLR_STOP_DET            (1 << 0)
+
+/* Clear START_DET Interrupt Register */
+#define IC_CLR_START_DET        0x64
+#define CLR_START_DET           (1 << 0)
+
+/* Clear GEN_CALL Interrupt Register */
+#define IC_CLR_GEN_CALL         0x68
+#define CLR_GEN_CALL            (1 << 0)
+
+/* Enable Register */
+#define IC_ENABLE               0x6c
+#define ENABLE                  (1 << 0)
+
+/* Status Register */
+#define IC_STATUS               0x70            /* Read Only */
+#define STAT_SLV_ACTIVITY       (1 << 6)        /* Slave not in idle */
+#define STAT_MST_ACTIVITY       (1 << 5)        /* Master not in idle */
+#define STAT_RFF                (1 << 4)        /* RX FIFO Full */
+#define STAT_RFNE               (1 << 3)        /* RX FIFO Not Empty */
+#define STAT_TFE                (1 << 2)        /* TX FIFO Empty */
+#define STAT_TFNF               (1 << 1)        /* TX FIFO Not Full */
+#define STAT_ACTIVITY           (1 << 0)        /* Activity Status */
+
+/* Transmit FIFO Level Register */
+#define IC_TXFLR                0x74            /* Read Only */
+#define TXFLR                   (1 << 0)        /* TX FIFO level */
+
+/* Receive FIFO Level Register */
+#define IC_RXFLR                0x78            /* Read Only */
+#define RXFLR                   (1 << 0)        /* RX FIFO level */
+
+/* Transmit Abort Source Register */
+#define IC_TX_ABRT_SOURCE       0x80
+#define ABRT_SLVRD_INTX         (1 << 15)
+#define ABRT_SLV_ARBLOST        (1 << 14)
+#define ABRT_SLVFLUSH_TXFIFO    (1 << 13)
+#define ARB_LOST                (1 << 12)
+#define ABRT_MASTER_DIS         (1 << 11)
+#define ABRT_10B_RD_NORSTRT     (1 << 10)
+#define ABRT_SBYTE_NORSTRT      (1 << 9)
+#define ABRT_HS_NORSTRT         (1 << 8)
+#define ABRT_SBYTE_ACKDET       (1 << 7)
+#define ABRT_HS_ACKDET          (1 << 6)
+#define ABRT_GCALL_READ         (1 << 5)
+#define ABRT_GCALL_NOACK        (1 << 4)
+#define ABRT_TXDATA_NOACK       (1 << 3)
+#define ABRT_10ADDR2_NOACK      (1 << 2)
+#define ABRT_10ADDR1_NOACK      (1 << 1)
+#define ABRT_7B_ADDR_NOACK      (1 << 0)
+
+/* Enable Status Register */
+#define IC_ENABLE_STATUS        0x9c
+#define IC_EN                   (1 << 0)        /* I2C in an enabled state */
+
+/* Component Parameter Register 1*/
+#define IC_COMP_PARAM_1         0xf4
+#define APB_DATA_WIDTH          (0x3 << 0)
+
+/* added by xiaolin --begin */
+#define SS_MIN_SCL_HIGH         4000
+#define SS_MIN_SCL_LOW          4700
+#define FS_MIN_SCL_HIGH         600
+#define FS_MIN_SCL_LOW          1300
+#define HS_MIN_SCL_HIGH_100PF   60
+#define HS_MIN_SCL_LOW_100PF    120
+
+#define STANDARD                0
+#define FAST                    1
+#define HIGH                    2
+
+#define NUM_SPEEDS              3
+
+static int speed_mode[6] = {
+        FAST,
+        FAST,
+        FAST,
+        STANDARD,
+        FAST,
+        FAST
+};
+
+static int ctl_num = 6;
+module_param_array(speed_mode, int, &ctl_num, S_IRUGO);
+MODULE_PARM_DESC(speed_mode, "Set the speed of the i2c interface (0-2)");
+
+/**
+ * intel_mid_i2c_disable - Disable I2C controller
+ * @adap: struct pointer to i2c_adapter
+ *
+ * Return Value:
+ * 0            success
+ * -EBUSY       if device is busy
+ * -ETIMEDOUT   if i2c cannot be disabled within the given time
+ *
+ * I2C bus state should be checked prior to disabling the hardware. If bus is
+ * not in idle state, an errno is returned. Write "0" to IC_ENABLE to disable
+ * I2C controller.
+ */
+static int intel_mid_i2c_disable(struct i2c_adapter *adap)
+{
+        struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
+        int err = 0;
+        int count = 0;
+        int ret1, ret2;
+        static const u16 delay[NUM_SPEEDS] = {100, 25, 3};
+
+        /* Set IC_ENABLE to 0 */
+        writel(0, i2c->base + IC_ENABLE);
+
+        /* Check if device is busy */
+        dev_dbg(&adap->dev, "mrst i2c disable\n");
+        while ((ret1 = readl(i2c->base + IC_ENABLE_STATUS) & 0x1)
+                || (ret2 = readl(i2c->base + IC_STATUS) & 0x1)) {
+                udelay(delay[i2c->speed]);
+                writel(0, i2c->base + IC_ENABLE);
+                dev_dbg(&adap->dev, "i2c is busy, count is %d speed %d\n",
+                        count, i2c->speed);
+                if (count++ > 10) {
+                        err = -ETIMEDOUT;
+                        break;
+                }
+        }
+
+        /* Clear all interrupts */
+        readl(i2c->base + IC_CLR_INTR);
+        readl(i2c->base + IC_CLR_STOP_DET);
+        readl(i2c->base + IC_CLR_START_DET);
+        readl(i2c->base + IC_CLR_ACTIVITY);
+        readl(i2c->base + IC_CLR_TX_ABRT);
+        readl(i2c->base + IC_CLR_RX_OVER);
+        readl(i2c->base + IC_CLR_RX_UNDER);
+        readl(i2c->base + IC_CLR_TX_OVER);
+        readl(i2c->base + IC_CLR_RX_DONE);
+        readl(i2c->base + IC_CLR_GEN_CALL);
+
+        /* Disable all interupts */
+        writel(0x0000, i2c->base + IC_INTR_MASK);
+
+        return err;
+}
+
+/**
+ * intel_mid_i2c_hwinit - Initialize the I2C hardware registers
+ * @dev: pci device struct pointer
+ *
+ * This function will be called in intel_mid_i2c_probe() before device
+ * registration.
+ *
+ * Return Values:
+ * 0            success
+ * -EBUSY       i2c cannot be disabled
+ * -ETIMEDOUT   i2c cannot be disabled
+ * -EFAULT      If APB data width is not 32-bit wide
+ *
+ * I2C should be disabled prior to other register operation. If failed, an
+ * errno is returned. Mask and Clear all interrpts, this should be done at
+ * first.  Set common registers which will not be modified during normal
+ * transfers, including: controll register, FIFO threshold and clock freq.
+ * Check APB data width at last.
+ */
+static int intel_mid_i2c_hwinit(struct intel_mid_i2c_private *i2c)
+{
+        int err;
+
+        static const u16 hcnt[NUM_PLATFORMS][NUM_SPEEDS] = {
+                { 0x75,  0x15, 0x07 },
+                { 0x04c,  0x10, 0x06 }
+        };
+        static const u16 lcnt[NUM_PLATFORMS][NUM_SPEEDS] = {
+                { 0x7C,  0x21, 0x0E },
+                { 0x053, 0x19, 0x0F }
+        };
+
+        /* Disable i2c first */
+        err = intel_mid_i2c_disable(&i2c->adap);
+        if (err)
+                return err;
+
+        /*
+         * Setup clock frequency and speed mode
+         * Enable restart condition,
+         * enable master FSM, disable slave FSM,
+         * use target address when initiating transfer
+         */
+
+        writel((i2c->speed + 1) << 1 | SLV_DIS | RESTART | MASTER_EN,
+                i2c->base + IC_CON);
+        writel(hcnt[i2c->platform][i2c->speed],
+                i2c->base + (IC_SS_SCL_HCNT + (i2c->speed << 3)));
+        writel(lcnt[i2c->platform][i2c->speed],
+                i2c->base + (IC_SS_SCL_LCNT + (i2c->speed << 3)));
+
+        /* Set tranmit & receive FIFO threshold to zero */
+        writel(0x0, i2c->base + IC_RX_TL);
+        writel(0x0, i2c->base + IC_TX_TL);
+
+        return 0;
+}
+
+/**
+ * intel_mid_i2c_func - Return the supported three I2C operations.
+ * @adapter: i2c_adapter struct pointer
+ */
+static u32 intel_mid_i2c_func(struct i2c_adapter *adapter)
+{
+        return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
+}
+
+/**
+ * intel_mid_i2c_address_neq - To check if the addresses for different i2c messages
+ * are equal.
+ * @p1: first i2c_msg
+ * @p2: second i2c_msg
+ *
+ * Return Values:
+ * 0     if addresses are equal
+ * 1     if not equal
+ *
+ * Within a single transfer, the I2C client may need to send its address more
+ * than once. So a check if the addresses match is needed.
+ */
+static inline bool intel_mid_i2c_address_neq(const struct i2c_msg *p1,
+                                       const struct i2c_msg *p2)
+{
+        if (p1->addr != p2->addr)
+                return 1;
+        if ((p1->flags ^ p2->flags) & I2C_M_TEN)
+                return 1;
+        return 0;
+}
+
+/**
+ * intel_mid_i2c_abort - To handle transfer abortions and print error messages.
+ * @adap: i2c_adapter struct pointer
+ *
+ * By reading register IC_TX_ABRT_SOURCE, various transfer errors can be
+ * distingushed. At present, no circumstances have been found out that
+ * multiple errors would be occured simutaneously, so we simply use the
+ * register value directly.
+ *
+ * At last the error bits are cleared. (Note clear ABRT_SBYTE_NORSTRT bit need
+ * a few extra steps)
+ */
+static void intel_mid_i2c_abort(struct intel_mid_i2c_private *i2c)
+{
+        /* Read about source register */
+        int abort = i2c->abort;
+        struct i2c_adapter *adap = &i2c->adap;
+
+        /* Single transfer error check:
+         * According to databook, TX/RX FIFOs would be flushed when
+         * the abort interrupt occured.
+         */
+        if (abort & ABRT_MASTER_DIS)
+                dev_err(&adap->dev,
+                "initiate master operation with master mode disabled.\n");
+        if (abort & ABRT_10B_RD_NORSTRT)
+                dev_err(&adap->dev,
+        "RESTART disabled and master sent READ cmd in 10-bit addressing.\n");
+
+        if (abort & ABRT_SBYTE_NORSTRT) {
+                dev_err(&adap->dev,
+                "RESTART disabled and user is trying to send START byte.\n");
+                writel(~ABRT_SBYTE_NORSTRT, i2c->base + IC_TX_ABRT_SOURCE);
+                writel(RESTART, i2c->base + IC_CON);
+                writel(~IC_TAR_SPECIAL, i2c->base + IC_TAR);
+        }
+
+        if (abort & ABRT_SBYTE_ACKDET)
+                dev_err(&adap->dev,
+                        "START byte was not acknowledged.\n");
+        if (abort & ABRT_TXDATA_NOACK)
+                dev_dbg(&adap->dev,
+                        "No acknowledgement received from slave.\n");
+        if (abort & ABRT_10ADDR2_NOACK)
+                dev_dbg(&adap->dev,
+        "The 2nd address byte of the 10-bit address was not acknowledged.\n");
+        if (abort & ABRT_10ADDR1_NOACK)
+                dev_dbg(&adap->dev,
+        "The 1st address byte of 10-bit address was not acknowledged.\n");
+        if (abort & ABRT_7B_ADDR_NOACK)
+                dev_dbg(&adap->dev,
+                        "I2C slave device not acknowledged.\n");
+
+        /* Clear TX_ABRT bit */
+        readl(i2c->base + IC_CLR_TX_ABRT);
+        i2c->status = STATUS_XFER_ABORT;
+}
+
+/**
+ * xfer_read - Internal function to implement master read transfer.
+ * @adap: i2c_adapter struct pointer
+ * @buf: buffer in i2c_msg
+ * @length: number of bytes to be read
+ *
+ * Return Values:
+ * 0            if the read transfer succeeds
+ * -ETIMEDOUT   if cannot read the "raw" interrupt register
+ * -EINVAL      if a transfer abort occurred
+ *
+ * For every byte, a "READ" command will be loaded into IC_DATA_CMD prior to
+ * data transfer. The actual "read" operation will be performed if an RX_FULL
+ * interrupt occurred.
+ *
+ * Note there may be two interrupt signals captured, one should read
+ * IC_RAW_INTR_STAT to separate between errors and actual data.
+ */
+static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length)
+{
+        struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
+        int i = length;
+        int err;
+
+        if (length >= 256) {
+                dev_err(&adap->dev,
+                        "I2C FIFO cannot support larger than 256 bytes\n");
+                return -EMSGSIZE;
+        }
+
+        INIT_COMPLETION(i2c->complete);
+
+        readl(i2c->base + IC_CLR_INTR);
+        writel(0x0044, i2c->base + IC_INTR_MASK);
+
+        i2c->status = STATUS_READ_START;
+
+        while (i--)
+                writel(IC_RD, i2c->base + IC_DATA_CMD);
+
+        i2c->status = STATUS_READ_START;
+        err = wait_for_completion_interruptible_timeout(&i2c->complete, HZ);
+        if (!err) {
+                dev_err(&adap->dev, "Timeout for ACK from I2C slave device\n");
+                intel_mid_i2c_hwinit(i2c);
+                return -ETIMEDOUT;
+        }
+        if (i2c->status == STATUS_READ_SUCCESS)
+                return 0;
+        else
+                return -EIO;
+}
+
+/**
+ * xfer_write - Internal function to implement master write transfer.
+ * @adap: i2c_adapter struct pointer
+ * @buf: buffer in i2c_msg
+ * @length: number of bytes to be read
+ *
+ * Return Values:
+ * 0    if the read transfer succeeds
+ * -ETIMEDOUT   if we cannot read the "raw" interrupt register
+ * -EINVAL      if a transfer abort occured
+ *
+ * For every byte, a "WRITE" command will be loaded into IC_DATA_CMD prior to
+ * data transfer. The actual "write" operation will be performed when the
+ * RX_FULL interrupt signal occurs.
+ *
+ * Note there may be two interrupt signals captured, one should read
+ * IC_RAW_INTR_STAT to separate between errors and actual data.
+ */
+static int xfer_write(struct i2c_adapter *adap,
+                      unsigned char *buf, int length)
+{
+        struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
+        int i, err;
+
+        if (length >= 256) {
+                dev_err(&adap->dev,
+                        "I2C FIFO cannot support larger than 256 bytes\n");
+                return -EMSGSIZE;
+        }
+
+        INIT_COMPLETION(i2c->complete);
+
+        readl(i2c->base + IC_CLR_INTR);
+        writel(0x0050, i2c->base + IC_INTR_MASK);
+
+        i2c->status = STATUS_WRITE_START;
+        for (i = 0; i < length; i++)
+                writel((u16)(*(buf + i)), i2c->base + IC_DATA_CMD);
+
+        i2c->status = STATUS_WRITE_START;
+        err = wait_for_completion_interruptible_timeout(&i2c->complete, HZ);
+        if (!err) {
+                dev_err(&adap->dev, "Timeout for ACK from I2C slave device\n");
+                intel_mid_i2c_hwinit(i2c);
+                return -ETIMEDOUT;
+        } else {
+                if (i2c->status == STATUS_WRITE_SUCCESS)
+                        return 0;
+                else
+                        return -EIO;
+        }
+}
+
+static int intel_mid_i2c_setup(struct i2c_adapter *adap,  struct i2c_msg *pmsg)
+{
+        struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
+        int err;
+        u32 reg;
+        u32 bit_mask;
+        u32 mode;
+
+        /* Disable device first */
+        err = intel_mid_i2c_disable(adap);
+        if (err) {
+                dev_err(&adap->dev,
+                        "Cannot disable i2c controller, timeout\n");
+                return err;
+        }
+
+        mode = (1 + i2c->speed) << 1;
+        /* set the speed mode */
+        reg = readl(i2c->base + IC_CON);
+        if ((reg & 0x06) != mode) {
+                dev_dbg(&adap->dev, "set mode %d\n", i2c->speed);
+                writel((reg & ~0x6) | mode, i2c->base + IC_CON);
+        }
+
+        reg = readl(i2c->base + IC_CON);
+        /* use 7-bit addressing */
+        if (pmsg->flags & I2C_M_TEN) {
+                if ((reg & ADDR_10BIT) != ADDR_10BIT) {
+                        dev_dbg(&adap->dev, "set i2c 10 bit address mode\n");
+                        writel(reg | ADDR_10BIT, i2c->base + IC_CON);
+                }
+        } else {
+                if ((reg & ADDR_10BIT) != 0x0) {
+                        dev_dbg(&adap->dev, "set i2c 7 bit address mode\n");
+                        writel(reg & ~ADDR_10BIT, i2c->base + IC_CON);
+                }
+        }
+        /* enable restart conditions */
+        reg = readl(i2c->base + IC_CON);
+        if ((reg & RESTART) != RESTART) {
+                dev_dbg(&adap->dev, "enable restart conditions\n");
+                writel(reg | RESTART, i2c->base + IC_CON);
+        }
+
+        /* enable master FSM */
+        reg = readl(i2c->base + IC_CON);
+        dev_dbg(&adap->dev, "ic_con reg is 0x%x\n", reg);
+        writel(reg | MASTER_EN, i2c->base + IC_CON);
+        if ((reg & SLV_DIS) != SLV_DIS) {
+                dev_dbg(&adap->dev, "enable master FSM\n");
+                writel(reg | SLV_DIS, i2c->base + IC_CON);
+                dev_dbg(&adap->dev, "ic_con reg is 0x%x\n", reg);
+        }
+
+        /* use target address when initiating transfer */
+        reg = readl(i2c->base + IC_TAR);
+        bit_mask = IC_TAR_SPECIAL | IC_TAR_GC_OR_START;
+
+        if ((reg & bit_mask) != 0x0) {
+                dev_dbg(&adap->dev,
+         "WR: use target address when intiating transfer, i2c_tx_target\n");
+                writel(reg & ~bit_mask, i2c->base + IC_TAR);
+        }
+
+        /* set target address to the I2C slave address */
+        dev_dbg(&adap->dev,
+                "set target address to the I2C slave address, addr is %x\n",
+                        pmsg->addr);
+        writel(pmsg->addr | (pmsg->flags & I2C_M_TEN ? IC_TAR_10BIT_ADDR : 0),
+                i2c->base + IC_TAR);
+
+        /* Enable I2C controller */
+        writel(ENABLE, i2c->base + IC_ENABLE);
+
+        return 0;
+}
+
+/**
+ * intel_mid_i2c_xfer - Main master transfer routine.
+ * @adap: i2c_adapter struct pointer
+ * @pmsg: i2c_msg struct pointer
+ * @num: number of i2c_msg
+ *
+ * Return Values:
+ * +            number of messages transfered
+ * -ETIMEDOUT   If cannot disable I2C controller or read IC_STATUS
+ * -EINVAL      If the address in i2c_msg is invalid
+ *
+ * This function will be registered in i2c-core and exposed to external
+ * I2C clients.
+ * 1. Disable I2C controller
+ * 2. Unmask three interrupts: RX_FULL, TX_EMPTY, TX_ABRT
+ * 3. Check if address in i2c_msg is valid
+ * 4. Enable I2C controller
+ * 5. Perform real transfer (call xfer_read or xfer_write)
+ * 6. Wait until the current transfer is finished (check bus state)
+ * 7. Mask and clear all interrupts
+ */
+static int intel_mid_i2c_xfer(struct i2c_adapter *adap,
+                         struct i2c_msg *pmsg,
+                         int num)
+{
+        struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
+        int i, err = 0;
+
+        /* if number of messages equal 0*/
+        if (num == 0)
+                return 0;
+
+        pm_runtime_get(i2c->dev);
+
+        mutex_lock(&i2c->lock);
+        dev_dbg(&adap->dev, "intel_mid_i2c_xfer, process %d msg(s)\n", num);
+        dev_dbg(&adap->dev, "slave address is %x\n", pmsg->addr);
+
+
+        if (i2c->status != STATUS_IDLE) {
+                dev_err(&adap->dev, "Adapter %d in transfer/standby\n",
+                                                                adap->nr);
+                mutex_unlock(&i2c->lock);
+                pm_runtime_put(i2c->dev);
+                return -1;
+        }
+
+
+        for (i = 1; i < num; i++) {
+                /* Message address equal? */
+                if (unlikely(intel_mid_i2c_address_neq(&pmsg[0], &pmsg[i]))) {
+                        dev_err(&adap->dev, "Invalid address in msg[%d]\n", i);
+                        mutex_unlock(&i2c->lock);
+                        pm_runtime_put(i2c->dev);
+                        return -EINVAL;
+                }
+        }
+
+        if (intel_mid_i2c_setup(adap, pmsg)) {
+                mutex_unlock(&i2c->lock);
+                pm_runtime_put(i2c->dev);
+                return -EINVAL;
+        }
+
+        for (i = 0; i < num; i++) {
+                i2c->msg = pmsg;
+                i2c->status = STATUS_IDLE;
+                /* Read or Write */
+                if (pmsg->flags & I2C_M_RD) {
+                        dev_dbg(&adap->dev, "I2C_M_RD\n");
+                        err = xfer_read(adap, pmsg->buf, pmsg->len);
+                } else {
+                        dev_dbg(&adap->dev, "I2C_M_WR\n");
+                        err = xfer_write(adap, pmsg->buf, pmsg->len);
+                }
+                if (err < 0)
+                        break;
+                dev_dbg(&adap->dev, "msg[%d] transfer complete\n", i);
+                pmsg++;         /* next message */
+        }
+
+        /* Mask interrupts */
+        writel(0x0000, i2c->base + IC_INTR_MASK);
+        /* Clear all interrupts */
+        readl(i2c->base + IC_CLR_INTR);
+
+        i2c->status = STATUS_IDLE;
+        mutex_unlock(&i2c->lock);
+        pm_runtime_put(i2c->dev);
+
+        return err;
+}
+
+static int intel_mid_i2c_runtime_suspend(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct intel_mid_i2c_private *i2c = pci_get_drvdata(pdev);
+        struct i2c_adapter *adap = to_i2c_adapter(dev);
+        int err;
+
+        if (i2c->status != STATUS_IDLE)
+                return -1;
+
+        intel_mid_i2c_disable(adap);
+
+        err = pci_save_state(pdev);
+        if (err) {
+                dev_err(dev, "pci_save_state failed\n");
+                return err;
+        }
+
+        err = pci_set_power_state(pdev, PCI_D3hot);
+        if (err) {
+                dev_err(dev, "pci_set_power_state failed\n");
+                return err;
+        }
+        i2c->status = STATUS_STANDBY;
+
+        return 0;
+}
+
+static int intel_mid_i2c_runtime_resume(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct intel_mid_i2c_private *i2c = pci_get_drvdata(pdev);
+        int err;
+
+        if (i2c->status != STATUS_STANDBY)
+                return 0;
+
+        pci_set_power_state(pdev, PCI_D0);
+        pci_restore_state(pdev);
+        err = pci_enable_device(pdev);
+        if (err) {
+                dev_err(dev, "pci_enable_device failed\n");
+                return err;
+        }
+
+        i2c->status = STATUS_IDLE;
+
+        intel_mid_i2c_hwinit(i2c);
+        return err;
+}
+
+static void i2c_isr_read(struct intel_mid_i2c_private *i2c)
+{
+        struct i2c_msg *msg = i2c->msg;
+        int rx_num;
+        u32 len;
+        u8 *buf;
+
+        if (!(msg->flags & I2C_M_RD))
+                return;
+
+        if (i2c->status != STATUS_READ_IN_PROGRESS) {
+                len = msg->len;
+                buf = msg->buf;
+        } else {
+                len = i2c->rx_buf_len;
+                buf = i2c->rx_buf;
+        }
+
+        rx_num = readl(i2c->base + IC_RXFLR);
+
+        for (; len > 0 && rx_num > 0; len--, rx_num--)
+                *buf++ = readl(i2c->base + IC_DATA_CMD);
+
+        if (len > 0) {
+                i2c->status = STATUS_READ_IN_PROGRESS;
+                i2c->rx_buf_len = len;
+                i2c->rx_buf = buf;
+        } else
+                i2c->status = STATUS_READ_SUCCESS;
+
+        return;
+}
+
+static irqreturn_t intel_mid_i2c_isr(int this_irq, void *dev)
+{
+        struct intel_mid_i2c_private *i2c = dev;
+        u32 stat = readl(i2c->base + IC_INTR_STAT);
+
+        if (!stat)
+                return IRQ_NONE;
+
+        dev_dbg(&i2c->adap.dev, "%s, stat = 0x%x\n", __func__, stat);
+        stat &= 0x54;
+
+        if (i2c->status != STATUS_WRITE_START &&
+            i2c->status != STATUS_READ_START &&
+            i2c->status != STATUS_READ_IN_PROGRESS)
+                goto err;
+
+        if (stat & TX_ABRT)
+                i2c->abort = readl(i2c->base + IC_TX_ABRT_SOURCE);
+
+        readl(i2c->base + IC_CLR_INTR);
+
+        if (stat & TX_ABRT) {
+                intel_mid_i2c_abort(i2c);
+                goto exit;
+        }
+
+        if (stat & RX_FULL) {
+                i2c_isr_read(i2c);
+                goto exit;
+        }
+
+        if (stat & TX_EMPTY) {
+                if (readl(i2c->base + IC_STATUS) & 0x4)
+                        i2c->status = STATUS_WRITE_SUCCESS;
+        }
+
+exit:
+        if (i2c->status == STATUS_READ_SUCCESS ||
+            i2c->status == STATUS_WRITE_SUCCESS ||
+            i2c->status == STATUS_XFER_ABORT) {
+                /* Clear all interrupts */
+                readl(i2c->base + IC_CLR_INTR);
+                /* Mask interrupts */
+                writel(0, i2c->base + IC_INTR_MASK);
+                complete(&i2c->complete);
+        }
+err:
+        return IRQ_HANDLED;
+}
+
+static struct i2c_algorithm intel_mid_i2c_algorithm = {
+        .master_xfer    = intel_mid_i2c_xfer,
+        .functionality  = intel_mid_i2c_func,
+};
+
+
+static const struct dev_pm_ops intel_mid_i2c_pm_ops = {
+        .runtime_suspend = intel_mid_i2c_runtime_suspend,
+        .runtime_resume = intel_mid_i2c_runtime_resume,
+};
+
+/**
+ * intel_mid_i2c_probe - I2C controller initialization routine
+ * @dev: pci device
+ * @id: device id
+ *
+ * Return Values:
+ * 0            success
+ * -ENODEV      If cannot allocate pci resource
+ * -ENOMEM      If the register base remapping failed, or
+ *              if kzalloc failed
+ *
+ * Initialization steps:
+ * 1. Request for PCI resource
+ * 2. Remap the start address of PCI resource to register base
+ * 3. Request for device memory region
+ * 4. Fill in the struct members of intel_mid_i2c_private
+ * 5. Call intel_mid_i2c_hwinit() for hardware initialization
+ * 6. Register I2C adapter in i2c-core
+ */
+static int __devinit intel_mid_i2c_probe(struct pci_dev *dev,
+                                    const struct pci_device_id *id)
+{
+        struct intel_mid_i2c_private *mrst;
+        unsigned long start, len;
+        int err, busnum;
+        void __iomem *base = NULL;
+
+        dev_dbg(&dev->dev, "Get into probe function for I2C\n");
+        err = pci_enable_device(dev);
+        if (err) {
+                dev_err(&dev->dev, "Failed to enable I2C PCI device (%d)\n",
+                        err);
+                goto exit;
+        }
+
+        /* Determine the address of the I2C area */
+        start = pci_resource_start(dev, 0);
+        len = pci_resource_len(dev, 0);
+        if (!start || len == 0) {
+                dev_err(&dev->dev, "base address not set\n");
+                err = -ENODEV;
+                goto exit;
+        }
+        dev_dbg(&dev->dev, "%s i2c resource start 0x%lx, len=%ld\n",
+                PLATFORM, start, len);
+
+        err = pci_request_region(dev, 0, DRIVER_NAME);
+        if (err) {
+                dev_err(&dev->dev, "failed to request I2C region "
+                        "0x%lx-0x%lx\n", start,
+                        (unsigned long)pci_resource_end(dev, 0));
+                goto exit;
+        }
+
+        base = ioremap_nocache(start, len);
+        if (!base) {
+                dev_err(&dev->dev, "I/O memory remapping failed\n");
+                err = -ENOMEM;
+                goto fail0;
+        }
+
+        /* Allocate the per-device data structure, intel_mid_i2c_private */
+        mrst = kzalloc(sizeof(struct intel_mid_i2c_private), GFP_KERNEL);
+        if (mrst == NULL) {
+                dev_err(&dev->dev, "can't allocate interface\n");
+                err = -ENOMEM;
+                goto fail1;
+        }
+
+        /* Initialize struct members */
+        snprintf(mrst->adap.name, sizeof(mrst->adap.name),
+                "MRST/Medfield I2C at %lx", start);
+        mrst->adap.owner = THIS_MODULE;
+        mrst->adap.algo = &intel_mid_i2c_algorithm;
+        mrst->adap.dev.parent = &dev->dev;
+        mrst->dev = &dev->dev;
+        mrst->base = base;
+        mrst->speed = STANDARD;
+        mrst->abort = 0;
+        mrst->rx_buf_len = 0;
+        mrst->status = STATUS_IDLE;
+
+        pci_set_drvdata(dev, mrst);
+        i2c_set_adapdata(&mrst->adap, mrst);
+
+        mrst->adap.nr = busnum = id->driver_data;
+        if (dev->device <= 0x0804)
+                mrst->platform = MOORESTOWN;
+        else
+                mrst->platform = MEDFIELD;
+
+        dev_dbg(&dev->dev, "I2C%d\n", busnum);
+
+        if (ctl_num > busnum) {
+                if (speed_mode[busnum] < 0 || speed_mode[busnum] >= NUM_SPEEDS)
+                        dev_warn(&dev->dev, "invalid speed %d ignored.\n",
+                                                        speed_mode[busnum]);
+                else
+                        mrst->speed = speed_mode[busnum];
+        }
+
+        /* Initialize i2c controller */
+        err = intel_mid_i2c_hwinit(mrst);
+        if (err < 0) {
+                dev_err(&dev->dev, "I2C interface initialization failed\n");
+                goto fail2;
+        }
+
+        mutex_init(&mrst->lock);
+        init_completion(&mrst->complete);
+
+        /* Clear all interrupts */
+        readl(mrst->base + IC_CLR_INTR);
+        writel(0x0000, mrst->base + IC_INTR_MASK);
+
+        err = request_irq(dev->irq, intel_mid_i2c_isr, IRQF_SHARED,
+                                        mrst->adap.name, mrst);
+        if (err) {
+                dev_err(&dev->dev, "Failed to request IRQ for I2C controller: "
+                        "%s", mrst->adap.name);
+                goto fail2;
+        }
+
+        /* Adapter registration */
+        err = i2c_add_numbered_adapter(&mrst->adap);
+        if (err) {
+                dev_err(&dev->dev, "Adapter %s registration failed\n",
+                        mrst->adap.name);
+                goto fail3;
+        }
+
+        dev_dbg(&dev->dev, "%s I2C bus %d driver bind success.\n",
+                (mrst->platform == MOORESTOWN) ? "Moorestown" : "Medfield",
+                busnum);
+
+        pm_runtime_enable(&dev->dev);
+        return 0;
+
+fail3:
+        free_irq(dev->irq, mrst);
+fail2:
+        pci_set_drvdata(dev, NULL);
+        kfree(mrst);
+fail1:
+        iounmap(base);
+fail0:
+        pci_release_region(dev, 0);
+exit:
+        return err;
+}
+
+static void __devexit intel_mid_i2c_remove(struct pci_dev *dev)
+{
+        struct intel_mid_i2c_private *mrst = pci_get_drvdata(dev);
+        intel_mid_i2c_disable(&mrst->adap);
+        if (i2c_del_adapter(&mrst->adap))
+                dev_err(&dev->dev, "Failed to delete i2c adapter");
+
+        free_irq(dev->irq, mrst);
+        pci_set_drvdata(dev, NULL);
+        iounmap(mrst->base);
+        kfree(mrst);
+        pci_release_region(dev, 0);
+}
+
+static struct pci_device_id intel_mid_i2c_ids[] = {
+        /* Moorestown */
+        { PCI_VDEVICE(INTEL, 0x0802), 0 },
+        { PCI_VDEVICE(INTEL, 0x0803), 1 },
+        { PCI_VDEVICE(INTEL, 0x0804), 2 },
+        /* Medfield */
+        { PCI_VDEVICE(INTEL, 0x0817), 3,},
+        { PCI_VDEVICE(INTEL, 0x0818), 4 },
+        { PCI_VDEVICE(INTEL, 0x0819), 5 },
+        { PCI_VDEVICE(INTEL, 0x082C), 0 },
+        { PCI_VDEVICE(INTEL, 0x082D), 1 },
+        { PCI_VDEVICE(INTEL, 0x082E), 2 },
+        { 0,}
+};
+MODULE_DEVICE_TABLE(pci, intel_mid_i2c_ids);
+
+static struct pci_driver intel_mid_i2c_driver = {
+        .name           = DRIVER_NAME,
+        .id_table       = intel_mid_i2c_ids,
+        .probe          = intel_mid_i2c_probe,
+        .remove         = __devexit_p(intel_mid_i2c_remove),
+};
+
+static int __init intel_mid_i2c_init(void)
+{
+        return pci_register_driver(&intel_mid_i2c_driver);
+}
+
+static void __exit intel_mid_i2c_exit(void)
+{
+        pci_unregister_driver(&intel_mid_i2c_driver);
+}
+
+module_init(intel_mid_i2c_init);
+module_exit(intel_mid_i2c_exit);
+
+MODULE_AUTHOR("Ba Zheng <zheng.ba@intel.com>");
+MODULE_DESCRIPTION("I2C driver for Moorestown Platform");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(VERSION);