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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>
This commit is contained in:
Virupax Sadashivpetimath 2011-05-13 12:30:34 +02:00 committed by Ben Dooks
parent ebd10e0783
commit 553553413a
1 changed files with 26 additions and 13 deletions
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39
drivers/i2c/busses/i2c-nomadik.c
View File

@ -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