1 files changed, 45 insertions, 9 deletions

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index fdd83277c8a8..827da0858136 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -672,9 +672,17 @@ omap_i2c_isr(int this_irq, void *dev_id)
                         break;
                 }
 
-                omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
-
                 err = 0;
+complete:
+                /*
+                 * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be
+                 * acked after the data operation is complete.
+                 * Ref: TRM SWPU114Q Figure 18-31
+                 */
+                omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat &
+                                ~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
+                                OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
+
                 if (stat & OMAP_I2C_STAT_NACK) {
                         err |= OMAP_I2C_STAT_NACK;
                         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
@@ -685,16 +693,22 @@ omap_i2c_isr(int this_irq, void *dev_id)
                         err |= OMAP_I2C_STAT_AL;
                 }
                 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
-                                        OMAP_I2C_STAT_AL))
+                                        OMAP_I2C_STAT_AL)) {
+                        omap_i2c_ack_stat(dev, stat &
+                                (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
+                                OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
                         omap_i2c_complete_cmd(dev, err);
+                        return IRQ_HANDLED;
+                }
                 if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
                         u8 num_bytes = 1;
                         if (dev->fifo_size) {
                                 if (stat & OMAP_I2C_STAT_RRDY)
                                         num_bytes = dev->fifo_size;
-                                else
-                                        num_bytes = omap_i2c_read_reg(dev,
-                                                        OMAP_I2C_BUFSTAT_REG);
+                                else    /* read RXSTAT on RDR interrupt */
+                                        num_bytes = (omap_i2c_read_reg(dev,
+                                                        OMAP_I2C_BUFSTAT_REG)
+                                                        >> 8) & 0x3F;
                         }
                         while (num_bytes) {
                                 num_bytes--;
@@ -731,9 +745,10 @@ omap_i2c_isr(int this_irq, void *dev_id)
                         if (dev->fifo_size) {
                                 if (stat & OMAP_I2C_STAT_XRDY)
                                         num_bytes = dev->fifo_size;
-                                else
+                                else    /* read TXSTAT on XDR interrupt */
                                         num_bytes = omap_i2c_read_reg(dev,
-                                                        OMAP_I2C_BUFSTAT_REG);
+                                                        OMAP_I2C_BUFSTAT_REG)
+                                                        & 0x3F;
                         }
                         while (num_bytes) {
                                 num_bytes--;
@@ -760,6 +775,27 @@ omap_i2c_isr(int this_irq, void *dev_id)
                                                         "data to send\n");
                                         break;
                                 }
+
+                                /*
+                                 * OMAP3430 Errata 1.153: When an XRDY/XDR
+                                 * is hit, wait for XUDF before writing data
+                                 * to DATA_REG. Otherwise some data bytes can
+                                 * be lost while transferring them from the
+                                 * memory to the I2C interface.
+                                 */
+
+                                if (dev->rev <= OMAP_I2C_REV_ON_3430) {
+                                                while (!(stat & OMAP_I2C_STAT_XUDF)) {
+                                                        if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
+                                                                omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
+                                                                err |= OMAP_I2C_STAT_XUDF;
+                                                                goto complete;
+                                                        }
+                                                        cpu_relax();
+                                                        stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+                                                }
+                                }
+
                                 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
                         }
                         omap_i2c_ack_stat(dev,
@@ -879,7 +915,7 @@ omap_i2c_probe(struct platform_device *pdev)
         i2c_set_adapdata(adap, dev);
         adap->owner = THIS_MODULE;
         adap->class = I2C_CLASS_HWMON;
-        strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
+        strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
         adap->algo = &omap_i2c_algo;
         adap->dev.parent = &pdev->dev;