i2c-nomadik: change the TX and RX threshold

1) Increase RX FIFO threshold so that there is a reduction in
the number of interrupts handled to complete a transaction.

2) Fill TX FIFO in the write function.

Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 26 insertions, 13 deletions

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index b49ff25a2688..e3cd62e40df5 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -447,6 +447,24 @@ static int read_i2c(struct nmk_i2c_dev *dev)
         return status;
 }
 
+static void fill_tx_fifo(struct nmk_i2c_dev *dev, int no_bytes)
+{
+        int count;
+
+        for (count = (no_bytes - 2);
+                        (count > 0) &&
+                        (dev->cli.count != 0);
+                        count--) {
+                /* write to the Tx FIFO */
+                writeb(*dev->cli.buffer,
+                        dev->virtbase + I2C_TFR);
+                dev->cli.buffer++;
+                dev->cli.count--;
+                dev->cli.xfer_bytes++;
+        }
+
+}
+
 /**
  * write_i2c() - Write data to I2C client.
  * @dev: private data of I2C Driver
@@ -474,8 +492,13 @@ static int write_i2c(struct nmk_i2c_dev *dev)
         init_completion(&dev->xfer_complete);
 
         /* enable interrupts by settings the masks */
-        irq_mask = (I2C_IT_TXFNE | I2C_IT_TXFOVR |
-                        I2C_IT_MAL | I2C_IT_BERR);
+        irq_mask = (I2C_IT_TXFOVR | I2C_IT_MAL | I2C_IT_BERR);
+
+        /* Fill the TX FIFO with transmit data */
+        fill_tx_fifo(dev, MAX_I2C_FIFO_THRESHOLD);
+
+        if (dev->cli.count != 0)
+                irq_mask |= I2C_IT_TXFNE;
 
         /*
          * check if we want to transfer a single or multiple bytes, if so
@@ -702,17 +725,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
                          */
                         disable_interrupts(dev, I2C_IT_TXFNE);
                 } else {
-                        for (count = (MAX_I2C_FIFO_THRESHOLD - tft - 2);
-                                        (count > 0) &&
-                                        (dev->cli.count != 0);
-                                        count--) {
-                                /* write to the Tx FIFO */
-                                writeb(*dev->cli.buffer,
-                                        dev->virtbase + I2C_TFR);
-                                dev->cli.buffer++;
-                                dev->cli.count--;
-                                dev->cli.xfer_bytes++;
-                        }
+                        fill_tx_fifo(dev, (MAX_I2C_FIFO_THRESHOLD - tft));
                         /*
                          * if done, close the transfer by disabling the
                          * corresponding TXFNE interrupt