From: Virupax Sadashivpetimath <virupax.sadashivpetimath@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Reviewed-by: Jonas Aberg <jonas.aberg@xxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
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
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