From: Virupax Sadashivpetimath <[email protected]>
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 <[email protected]> Reviewed-by: Jonas Aberg <[email protected]> Signed-off-by: Linus Walleij <[email protected]> --- drivers/i2c/busses/i2c-nomadik.c | 39 +++++++++++++++++++++++++------------ 1 files changed, 26 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c index bf061e1..916e4db 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 -- 1.7.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
