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| author | Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com> | 2011-05-13 12:30:34 +0200 |
|---|---|---|
| committer | Ben Dooks <ben-linux@fluff.org> | 2011-05-25 00:20:47 +0100 |
| commit | 553553413a6abdda220a697ef439ba2f4b1d4a7c (patch) | |
| tree | 7f3ea5e0f05c9cd00cb845e458f13ea1c5e968fd /drivers/i2c | |
| parent | ebd10e0783d9fb92a147e60902e22c2d3f3ad69d (diff) | |
| download | linux-553553413a6abdda220a697ef439ba2f4b1d4a7c.tar.gz | |
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>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | 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 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 |