Merge branch 'wip-2.6.34' into old-private-masterarchived-private-master

1 files changed, 356 insertions, 133 deletions

diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
index b444762e9b9f..b664ed8bbdb3 100644
--- a/drivers/i2c/busses/i2c-designware.c
+++ b/drivers/i2c/busses/i2c-designware.c
@@ -1,5 +1,5 @@
 /*
- * Synopsys Designware I2C adapter driver (master only).
+ * Synopsys DesignWare I2C adapter driver (master only).
  *
  * Based on the TI DAVINCI I2C adapter driver.
  *
@@ -36,6 +36,7 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/slab.h>
 
 /*
  * Registers offset
@@ -49,7 +50,20 @@
 #define DW_IC_FS_SCL_LCNT       0x20
 #define DW_IC_INTR_STAT         0x2c
 #define DW_IC_INTR_MASK         0x30
+#define DW_IC_RAW_INTR_STAT     0x34
+#define DW_IC_RX_TL             0x38
+#define DW_IC_TX_TL             0x3c
 #define DW_IC_CLR_INTR          0x40
+#define DW_IC_CLR_RX_UNDER      0x44
+#define DW_IC_CLR_RX_OVER       0x48
+#define DW_IC_CLR_TX_OVER       0x4c
+#define DW_IC_CLR_RD_REQ        0x50
+#define DW_IC_CLR_TX_ABRT       0x54
+#define DW_IC_CLR_RX_DONE       0x58
+#define DW_IC_CLR_ACTIVITY      0x5c
+#define DW_IC_CLR_STOP_DET      0x60
+#define DW_IC_CLR_START_DET     0x64
+#define DW_IC_CLR_GEN_CALL      0x68
 #define DW_IC_ENABLE            0x6c
 #define DW_IC_STATUS            0x70
 #define DW_IC_TXFLR             0x74
@@ -64,9 +78,23 @@
 #define DW_IC_CON_RESTART_EN            0x20
 #define DW_IC_CON_SLAVE_DISABLE         0x40
 
-#define DW_IC_INTR_TX_EMPTY     0x10
-#define DW_IC_INTR_TX_ABRT      0x40
+#define DW_IC_INTR_RX_UNDER     0x001
+#define DW_IC_INTR_RX_OVER      0x002
+#define DW_IC_INTR_RX_FULL      0x004
+#define DW_IC_INTR_TX_OVER      0x008
+#define DW_IC_INTR_TX_EMPTY     0x010
+#define DW_IC_INTR_RD_REQ       0x020
+#define DW_IC_INTR_TX_ABRT      0x040
+#define DW_IC_INTR_RX_DONE      0x080
+#define DW_IC_INTR_ACTIVITY     0x100
 #define DW_IC_INTR_STOP_DET     0x200
+#define DW_IC_INTR_START_DET    0x400
+#define DW_IC_INTR_GEN_CALL     0x800
+
+#define DW_IC_INTR_DEFAULT_MASK         (DW_IC_INTR_RX_FULL | \
+                                         DW_IC_INTR_TX_EMPTY | \
+                                         DW_IC_INTR_TX_ABRT | \
+                                         DW_IC_INTR_STOP_DET)
 
 #define DW_IC_STATUS_ACTIVITY   0x1
 
@@ -96,31 +124,49 @@
 #define ABRT_SBYTE_ACKDET       7
 #define ABRT_SBYTE_NORSTRT      9
 #define ABRT_10B_RD_NORSTRT     10
-#define ARB_MASTER_DIS          11
+#define ABRT_MASTER_DIS         11
 #define ARB_LOST                12
 
+#define DW_IC_TX_ABRT_7B_ADDR_NOACK     (1UL << ABRT_7B_ADDR_NOACK)
+#define DW_IC_TX_ABRT_10ADDR1_NOACK     (1UL << ABRT_10ADDR1_NOACK)
+#define DW_IC_TX_ABRT_10ADDR2_NOACK     (1UL << ABRT_10ADDR2_NOACK)
+#define DW_IC_TX_ABRT_TXDATA_NOACK      (1UL << ABRT_TXDATA_NOACK)
+#define DW_IC_TX_ABRT_GCALL_NOACK       (1UL << ABRT_GCALL_NOACK)
+#define DW_IC_TX_ABRT_GCALL_READ        (1UL << ABRT_GCALL_READ)
+#define DW_IC_TX_ABRT_SBYTE_ACKDET      (1UL << ABRT_SBYTE_ACKDET)
+#define DW_IC_TX_ABRT_SBYTE_NORSTRT     (1UL << ABRT_SBYTE_NORSTRT)
+#define DW_IC_TX_ABRT_10B_RD_NORSTRT    (1UL << ABRT_10B_RD_NORSTRT)
+#define DW_IC_TX_ABRT_MASTER_DIS        (1UL << ABRT_MASTER_DIS)
+#define DW_IC_TX_ARB_LOST               (1UL << ARB_LOST)
+
+#define DW_IC_TX_ABRT_NOACK             (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
+                                         DW_IC_TX_ABRT_10ADDR1_NOACK | \
+                                         DW_IC_TX_ABRT_10ADDR2_NOACK | \
+                                         DW_IC_TX_ABRT_TXDATA_NOACK | \
+                                         DW_IC_TX_ABRT_GCALL_NOACK)
+
 static char *abort_sources[] = {
-        [ABRT_7B_ADDR_NOACK]    =
+        [ABRT_7B_ADDR_NOACK] =
                 "slave address not acknowledged (7bit mode)",
-        [ABRT_10ADDR1_NOACK]    =
+        [ABRT_10ADDR1_NOACK] =
                 "first address byte not acknowledged (10bit mode)",
-        [ABRT_10ADDR2_NOACK]    =
+        [ABRT_10ADDR2_NOACK] =
                 "second address byte not acknowledged (10bit mode)",
-        [ABRT_TXDATA_NOACK]             =
+        [ABRT_TXDATA_NOACK] =
                 "data not acknowledged",
-        [ABRT_GCALL_NOACK]              =
+        [ABRT_GCALL_NOACK] =
                 "no acknowledgement for a general call",
-        [ABRT_GCALL_READ]               =
+        [ABRT_GCALL_READ] =
                 "read after general call",
-        [ABRT_SBYTE_ACKDET]             =
+        [ABRT_SBYTE_ACKDET] =
                 "start byte acknowledged",
-        [ABRT_SBYTE_NORSTRT]    =
+        [ABRT_SBYTE_NORSTRT] =
                 "trying to send start byte when restart is disabled",
-        [ABRT_10B_RD_NORSTRT]   =
+        [ABRT_10B_RD_NORSTRT] =
                 "trying to read when restart is disabled (10bit mode)",
-        [ARB_MASTER_DIS]                =
+        [ABRT_MASTER_DIS] =
                 "trying to use disabled adapter",
-        [ARB_LOST]                      =
+        [ARB_LOST] =
                 "lost arbitration",
 };
 
@@ -129,7 +175,6 @@ static char *abort_sources[] = {
  * @dev: driver model device node
  * @base: IO registers pointer
  * @cmd_complete: tx completion indicator
- * @pump_msg: continue in progress transfers
  * @lock: protect this struct and IO registers
  * @clk: input reference clock
  * @cmd_err: run time hadware error code
@@ -155,27 +200,81 @@ struct dw_i2c_dev {
         struct device           *dev;
         void __iomem            *base;
         struct completion       cmd_complete;
-        struct tasklet_struct   pump_msg;
         struct mutex            lock;
         struct clk              *clk;
         int                     cmd_err;
         struct i2c_msg          *msgs;
         int                     msgs_num;
         int                     msg_write_idx;
-        u16                     tx_buf_len;
+        u32                     tx_buf_len;
         u8                      *tx_buf;
         int                     msg_read_idx;
-        u16                     rx_buf_len;
+        u32                     rx_buf_len;
         u8                      *rx_buf;
         int                     msg_err;
         unsigned int            status;
-        u16                     abort_source;
+        u32                     abort_source;
         int                     irq;
         struct i2c_adapter      adapter;
         unsigned int            tx_fifo_depth;
         unsigned int            rx_fifo_depth;
 };
 
+static u32
+i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
+{
+        /*
+         * DesignWare I2C core doesn't seem to have solid strategy to meet
+         * the tHD;STA timing spec.  Configuring _HCNT based on tHIGH spec
+         * will result in violation of the tHD;STA spec.
+         */
+        if (cond)
+                /*
+                 * Conditional expression:
+                 *
+                 *   IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
+                 *
+                 * This is based on the DW manuals, and represents an ideal
+                 * configuration.  The resulting I2C bus speed will be
+                 * faster than any of the others.
+                 *
+                 * If your hardware is free from tHD;STA issue, try this one.
+                 */
+                return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
+        else
+                /*
+                 * Conditional expression:
+                 *
+                 *   IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
+                 *
+                 * This is just experimental rule; the tHD;STA period turned
+                 * out to be proportinal to (_HCNT + 3).  With this setting,
+                 * we could meet both tHIGH and tHD;STA timing specs.
+                 *
+                 * If unsure, you'd better to take this alternative.
+                 *
+                 * The reason why we need to take into account "tf" here,
+                 * is the same as described in i2c_dw_scl_lcnt().
+                 */
+                return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
+}
+
+static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
+{
+        /*
+         * Conditional expression:
+         *
+         *   IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
+         *
+         * DW I2C core starts counting the SCL CNTs for the LOW period
+         * of the SCL clock (tLOW) as soon as it pulls the SCL line.
+         * In order to meet the tLOW timing spec, we need to take into
+         * account the fall time of SCL signal (tf).  Default tf value
+         * should be 0.3 us, for safety.
+         */
+        return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
+}
+
 /**
  * i2c_dw_init() - initialize the designware i2c master hardware
  * @dev: device private data
@@ -187,25 +286,49 @@ struct dw_i2c_dev {
 static void i2c_dw_init(struct dw_i2c_dev *dev)
 {
         u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
-        u16 ic_con;
+        u32 ic_con, hcnt, lcnt;
 
         /* Disable the adapter */
-        writeb(0, dev->base + DW_IC_ENABLE);
+        writel(0, dev->base + DW_IC_ENABLE);
 
         /* set standard and fast speed deviders for high/low periods */
-        writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
-                        dev->base + DW_IC_SS_SCL_HCNT);
-        writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
-                        dev->base + DW_IC_SS_SCL_LCNT);
-        writew((input_clock_khz *  6 / 10000)+1, /* fast speed high, 0.6us */
-                        dev->base + DW_IC_FS_SCL_HCNT);
-        writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
-                        dev->base + DW_IC_FS_SCL_LCNT);
+
+        /* Standard-mode */
+        hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+                                40,     /* tHD;STA = tHIGH = 4.0 us */
+                                3,      /* tf = 0.3 us */
+                                0,      /* 0: DW default, 1: Ideal */
+                                0);     /* No offset */
+        lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+                                47,     /* tLOW = 4.7 us */
+                                3,      /* tf = 0.3 us */
+                                0);     /* No offset */
+        writel(hcnt, dev->base + DW_IC_SS_SCL_HCNT);
+        writel(lcnt, dev->base + DW_IC_SS_SCL_LCNT);
+        dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
+
+        /* Fast-mode */
+        hcnt = i2c_dw_scl_hcnt(input_clock_khz,
+                                6,      /* tHD;STA = tHIGH = 0.6 us */
+                                3,      /* tf = 0.3 us */
+                                0,      /* 0: DW default, 1: Ideal */
+                                0);     /* No offset */
+        lcnt = i2c_dw_scl_lcnt(input_clock_khz,
+                                13,     /* tLOW = 1.3 us */
+                                3,      /* tf = 0.3 us */
+                                0);     /* No offset */
+        writel(hcnt, dev->base + DW_IC_FS_SCL_HCNT);
+        writel(lcnt, dev->base + DW_IC_FS_SCL_LCNT);
+        dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
+
+        /* Configure Tx/Rx FIFO threshold levels */
+        writel(dev->tx_fifo_depth - 1, dev->base + DW_IC_TX_TL);
+        writel(0, dev->base + DW_IC_RX_TL);
 
         /* configure the i2c master */
         ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
                 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
-        writew(ic_con, dev->base + DW_IC_CON);
+        writel(ic_con, dev->base + DW_IC_CON);
 }
 
 /*
@@ -215,7 +338,7 @@ static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
 {
         int timeout = TIMEOUT;
 
-        while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
+        while (readl(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
                 if (timeout <= 0) {
                         dev_warn(dev->dev, "timeout waiting for bus ready\n");
                         return -ETIMEDOUT;
@@ -227,106 +350,125 @@ static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
         return 0;
 }
 
+static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
+{
+        struct i2c_msg *msgs = dev->msgs;
+        u32 ic_con;
+
+        /* Disable the adapter */
+        writel(0, dev->base + DW_IC_ENABLE);
+
+        /* set the slave (target) address */
+        writel(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
+
+        /* if the slave address is ten bit address, enable 10BITADDR */
+        ic_con = readl(dev->base + DW_IC_CON);
+        if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
+                ic_con |= DW_IC_CON_10BITADDR_MASTER;
+        else
+                ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
+        writel(ic_con, dev->base + DW_IC_CON);
+
+        /* Enable the adapter */
+        writel(1, dev->base + DW_IC_ENABLE);
+
+        /* Enable interrupts */
+        writel(DW_IC_INTR_DEFAULT_MASK, dev->base + DW_IC_INTR_MASK);
+}
+
 /*
- * Initiate low level master read/write transaction.
- * This function is called from i2c_dw_xfer when starting a transfer.
- * This function is also called from dw_i2c_pump_msg to continue a transfer
- * that is longer than the size of the TX FIFO.
+ * Initiate (and continue) low level master read/write transaction.
+ * This function is only called from i2c_dw_isr, and pumping i2c_msg
+ * messages into the tx buffer.  Even if the size of i2c_msg data is
+ * longer than the size of the tx buffer, it handles everything.
  */
 static void
-i2c_dw_xfer_msg(struct i2c_adapter *adap)
+i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 {
-        struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
         struct i2c_msg *msgs = dev->msgs;
-        int num = dev->msgs_num;
-        u16 ic_con, intr_mask;
-        int tx_limit = dev->tx_fifo_depth - readb(dev->base + DW_IC_TXFLR);
-        int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR);
-        u16 addr = msgs[dev->msg_write_idx].addr;
-        u16 buf_len = dev->tx_buf_len;
-
-        if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
-                /* Disable the adapter */
-                writeb(0, dev->base + DW_IC_ENABLE);
-
-                /* set the slave (target) address */
-                writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
+        u32 intr_mask;
+        int tx_limit, rx_limit;
+        u32 addr = msgs[dev->msg_write_idx].addr;
+        u32 buf_len = dev->tx_buf_len;
+        u8 *buf = dev->tx_buf;;
 
-                /* if the slave address is ten bit address, enable 10BITADDR */
-                ic_con = readw(dev->base + DW_IC_CON);
-                if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
-                        ic_con |= DW_IC_CON_10BITADDR_MASTER;
-                else
-                        ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
-                writew(ic_con, dev->base + DW_IC_CON);
+        intr_mask = DW_IC_INTR_DEFAULT_MASK;
 
-                /* Enable the adapter */
-                writeb(1, dev->base + DW_IC_ENABLE);
-        }
-
-        for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
-                /* if target address has changed, we need to
+        for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
+                /*
+                 * if target address has changed, we need to
                  * reprogram the target address in the i2c
                  * adapter when we are done with this transfer
                  */
-                if (msgs[dev->msg_write_idx].addr != addr)
-                        return;
+                if (msgs[dev->msg_write_idx].addr != addr) {
+                        dev_err(dev->dev,
+                                "%s: invalid target address\n", __func__);
+                        dev->msg_err = -EINVAL;
+                        break;
+                }
 
                 if (msgs[dev->msg_write_idx].len == 0) {
                         dev_err(dev->dev,
                                 "%s: invalid message length\n", __func__);
                         dev->msg_err = -EINVAL;
-                        return;
+                        break;
                 }
 
                 if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
                         /* new i2c_msg */
-                        dev->tx_buf = msgs[dev->msg_write_idx].buf;
+                        buf = msgs[dev->msg_write_idx].buf;
                         buf_len = msgs[dev->msg_write_idx].len;
                 }
 
+                tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR);
+                rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR);
+
                 while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
                         if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
-                                writew(0x100, dev->base + DW_IC_DATA_CMD);
+                                writel(0x100, dev->base + DW_IC_DATA_CMD);
                                 rx_limit--;
                         } else
-                                writew(*(dev->tx_buf++),
-                                                dev->base + DW_IC_DATA_CMD);
+                                writel(*buf++, dev->base + DW_IC_DATA_CMD);
                         tx_limit--; buf_len--;
                 }
+
+                dev->tx_buf = buf;
+                dev->tx_buf_len = buf_len;
+
+                if (buf_len > 0) {
+                        /* more bytes to be written */
+                        dev->status |= STATUS_WRITE_IN_PROGRESS;
+                        break;
+                } else
+                        dev->status &= ~STATUS_WRITE_IN_PROGRESS;
         }
 
-        intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
-        if (buf_len > 0) { /* more bytes to be written */
-                intr_mask |= DW_IC_INTR_TX_EMPTY;
-                dev->status |= STATUS_WRITE_IN_PROGRESS;
-        } else
-                dev->status &= ~STATUS_WRITE_IN_PROGRESS;
-        writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+        /*
+         * If i2c_msg index search is completed, we don't need TX_EMPTY
+         * interrupt any more.
+         */
+        if (dev->msg_write_idx == dev->msgs_num)
+                intr_mask &= ~DW_IC_INTR_TX_EMPTY;
+
+        if (dev->msg_err)
+                intr_mask = 0;
 
-        dev->tx_buf_len = buf_len;
+        writel(intr_mask, dev->base + DW_IC_INTR_MASK);
 }
 
 static void
-i2c_dw_read(struct i2c_adapter *adap)
+i2c_dw_read(struct dw_i2c_dev *dev)
 {
-        struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
         struct i2c_msg *msgs = dev->msgs;
-        int num = dev->msgs_num;
-        u16 addr = msgs[dev->msg_read_idx].addr;
-        int rx_valid = readw(dev->base + DW_IC_RXFLR);
+        int rx_valid;
 
-        for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
-                u16 len;
+        for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
+                u32 len;
                 u8 *buf;
 
                 if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
                         continue;
 
-                /* different i2c client, reprogram the i2c adapter */
-                if (msgs[dev->msg_read_idx].addr != addr)
-                        return;
-
                 if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
                         len = msgs[dev->msg_read_idx].len;
                         buf = msgs[dev->msg_read_idx].buf;
@@ -335,8 +477,10 @@ i2c_dw_read(struct i2c_adapter *adap)
                         buf = dev->rx_buf;
                 }
 
+                rx_valid = readl(dev->base + DW_IC_RXFLR);
+
                 for (; len > 0 && rx_valid > 0; len--, rx_valid--)
-                        *buf++ = readb(dev->base + DW_IC_DATA_CMD);
+                        *buf++ = readl(dev->base + DW_IC_DATA_CMD);
 
                 if (len > 0) {
                         dev->status |= STATUS_READ_IN_PROGRESS;
@@ -348,6 +492,29 @@ i2c_dw_read(struct i2c_adapter *adap)
         }
 }
 
+static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
+{
+        unsigned long abort_source = dev->abort_source;
+        int i;
+
+        if (abort_source & DW_IC_TX_ABRT_NOACK) {
+                for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
+                        dev_dbg(dev->dev,
+                                "%s: %s\n", __func__, abort_sources[i]);
+                return -EREMOTEIO;
+        }
+
+        for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
+                dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
+
+        if (abort_source & DW_IC_TX_ARB_LOST)
+                return -EAGAIN;
+        else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
+                return -EINVAL; /* wrong msgs[] data */
+        else
+                return -EIO;
+}
+
 /*
  * Prepare controller for a transaction and call i2c_dw_xfer_msg
  */
@@ -369,13 +536,14 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
         dev->msg_read_idx = 0;
         dev->msg_err = 0;
         dev->status = STATUS_IDLE;
+        dev->abort_source = 0;
 
         ret = i2c_dw_wait_bus_not_busy(dev);
         if (ret < 0)
                 goto done;
 
         /* start the transfers */
-        i2c_dw_xfer_msg(adap);
+        i2c_dw_xfer_init(dev);
 
         /* wait for tx to complete */
         ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
@@ -394,23 +562,16 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 
         /* no error */
         if (likely(!dev->cmd_err)) {
-                /* read rx fifo, and disable the adapter */
-                do {
-                        i2c_dw_read(adap);
-                } while (dev->status & STATUS_READ_IN_PROGRESS);
-                writeb(0, dev->base + DW_IC_ENABLE);
+                /* Disable the adapter */
+                writel(0, dev->base + DW_IC_ENABLE);
                 ret = num;
                 goto done;
         }
 
         /* We have an error */
         if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
-                unsigned long abort_source = dev->abort_source;
-                int i;
-
-                for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
-                    dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
-                }
+                ret = i2c_dw_handle_tx_abort(dev);
+                goto done;
         }
         ret = -EIO;
 
@@ -422,21 +583,67 @@ done:
 
 static u32 i2c_dw_func(struct i2c_adapter *adap)
 {
-        return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
+        return  I2C_FUNC_I2C |
+                I2C_FUNC_10BIT_ADDR |
+                I2C_FUNC_SMBUS_BYTE |
+                I2C_FUNC_SMBUS_BYTE_DATA |
+                I2C_FUNC_SMBUS_WORD_DATA |
+                I2C_FUNC_SMBUS_I2C_BLOCK;
 }
 
-static void dw_i2c_pump_msg(unsigned long data)
+static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
 {
-        struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
-        u16 intr_mask;
-
-        i2c_dw_read(&dev->adapter);
-        i2c_dw_xfer_msg(&dev->adapter);
-
-        intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
-        if (dev->status & STATUS_WRITE_IN_PROGRESS)
-                intr_mask |= DW_IC_INTR_TX_EMPTY;
-        writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+        u32 stat;
+
+        /*
+         * The IC_INTR_STAT register just indicates "enabled" interrupts.
+         * Ths unmasked raw version of interrupt status bits are available
+         * in the IC_RAW_INTR_STAT register.
+         *
+         * That is,
+         *   stat = readl(IC_INTR_STAT);
+         * equals to,
+         *   stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK);
+         *
+         * The raw version might be useful for debugging purposes.
+         */
+        stat = readl(dev->base + DW_IC_INTR_STAT);
+
+        /*
+         * Do not use the IC_CLR_INTR register to clear interrupts, or
+         * you'll miss some interrupts, triggered during the period from
+         * readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
+         *
+         * Instead, use the separately-prepared IC_CLR_* registers.
+         */
+        if (stat & DW_IC_INTR_RX_UNDER)
+                readl(dev->base + DW_IC_CLR_RX_UNDER);
+        if (stat & DW_IC_INTR_RX_OVER)
+                readl(dev->base + DW_IC_CLR_RX_OVER);
+        if (stat & DW_IC_INTR_TX_OVER)
+                readl(dev->base + DW_IC_CLR_TX_OVER);
+        if (stat & DW_IC_INTR_RD_REQ)
+                readl(dev->base + DW_IC_CLR_RD_REQ);
+        if (stat & DW_IC_INTR_TX_ABRT) {
+                /*
+                 * The IC_TX_ABRT_SOURCE register is cleared whenever
+                 * the IC_CLR_TX_ABRT is read.  Preserve it beforehand.
+                 */
+                dev->abort_source = readl(dev->base + DW_IC_TX_ABRT_SOURCE);
+                readl(dev->base + DW_IC_CLR_TX_ABRT);
+        }
+        if (stat & DW_IC_INTR_RX_DONE)
+                readl(dev->base + DW_IC_CLR_RX_DONE);
+        if (stat & DW_IC_INTR_ACTIVITY)
+                readl(dev->base + DW_IC_CLR_ACTIVITY);
+        if (stat & DW_IC_INTR_STOP_DET)
+                readl(dev->base + DW_IC_CLR_STOP_DET);
+        if (stat & DW_IC_INTR_START_DET)
+                readl(dev->base + DW_IC_CLR_START_DET);
+        if (stat & DW_IC_INTR_GEN_CALL)
+                readl(dev->base + DW_IC_CLR_GEN_CALL);
+
+        return stat;
 }
 
 /*
@@ -446,20 +653,37 @@ static void dw_i2c_pump_msg(unsigned long data)
 static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
 {
         struct dw_i2c_dev *dev = dev_id;
-        u16 stat;
+        u32 stat;
 
-        stat = readw(dev->base + DW_IC_INTR_STAT);
+        stat = i2c_dw_read_clear_intrbits(dev);
         dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
+
         if (stat & DW_IC_INTR_TX_ABRT) {
-                dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
                 dev->cmd_err |= DW_IC_ERR_TX_ABRT;
                 dev->status = STATUS_IDLE;
-        } else if (stat & DW_IC_INTR_TX_EMPTY)
-                tasklet_schedule(&dev->pump_msg);
 
-        readb(dev->base + DW_IC_CLR_INTR);      /* clear interrupts */
-        writew(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
-        if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
+                /*
+                 * Anytime TX_ABRT is set, the contents of the tx/rx
+                 * buffers are flushed.  Make sure to skip them.
+                 */
+                writel(0, dev->base + DW_IC_INTR_MASK);
+                goto tx_aborted;
+        }
+
+        if (stat & DW_IC_INTR_RX_FULL)
+                i2c_dw_read(dev);
+
+        if (stat & DW_IC_INTR_TX_EMPTY)
+                i2c_dw_xfer_msg(dev);
+
+        /*
+         * No need to modify or disable the interrupt mask here.
+         * i2c_dw_xfer_msg() will take care of it according to
+         * the current transmit status.
+         */
+
+tx_aborted:
+        if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
                 complete(&dev->cmd_complete);
 
         return IRQ_HANDLED;
@@ -474,8 +698,8 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
 {
         struct dw_i2c_dev *dev;
         struct i2c_adapter *adap;
-        struct resource *mem, *irq, *ioarea;
-        int r;
+        struct resource *mem, *ioarea;
+        int irq, r;
 
         /* NOTE: driver uses the static register mapping */
         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -484,10 +708,10 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
                 return -EINVAL;
         }
 
-        irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-        if (!irq) {
+        irq = platform_get_irq(pdev, 0);
+        if (irq < 0) {
                 dev_err(&pdev->dev, "no irq resource?\n");
-                return -EINVAL;
+                return irq; /* -ENXIO */
         }
 
         ioarea = request_mem_region(mem->start, resource_size(mem),
@@ -504,10 +728,9 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
         }
 
         init_completion(&dev->cmd_complete);
-        tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
         mutex_init(&dev->lock);
         dev->dev = get_device(&pdev->dev);
-        dev->irq = irq->start;
+        dev->irq = irq;
         platform_set_drvdata(pdev, dev);
 
         dev->clk = clk_get(&pdev->dev, NULL);
@@ -531,8 +754,8 @@ static int __devinit dw_i2c_probe(struct platform_device *pdev)
         }
         i2c_dw_init(dev);
 
-        writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
-        r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
+        writel(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
+        r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
         if (r) {
                 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
                 goto err_iounmap;
@@ -587,7 +810,7 @@ static int __devexit dw_i2c_remove(struct platform_device *pdev)
         clk_put(dev->clk);
         dev->clk = NULL;
 
-        writeb(0, dev->base + DW_IC_ENABLE);
+        writel(0, dev->base + DW_IC_ENABLE);
         free_irq(dev->irq, dev);
         kfree(dev);