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authorAxel Lin <axel.lin@ingics.com>2013-08-15 14:18:46 +0800
committerMark Brown <broonie@linaro.org>2013-08-28 14:18:45 +0100
commit72be0ee42ebaf744d4a5cf684ee68dba59d6bac1 (patch)
tree09e081812af8a2da2b288d8e1ea30fdf31853edc /drivers/spi/spi-altera.c
parentd8dfad3876e4386666b759da3c833d62fb8b2267 (diff)
downloadlinux-72be0ee42ebaf744d4a5cf684ee68dba59d6bac1.tar.bz2
spi: altera: Simplify altera_spi_txrx implementation for noirq case
This patch simplifies the code and makes it better in readability. Now the logic in the while loop is simply "write to ALTERA_SPI_TXDATA then read from ALTERA_SPI_TXDATA". There is a slightly logic change because now we avoid a read-write cycle when hw->len is 0. Since the code in bitbang library will call bitbang->txrx_bufs() only when t->len is not 0, this is not a problem. Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Thomas Chou <thomas@wytron.com.tw> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers/spi/spi-altera.c')
-rw-r--r--drivers/spi/spi-altera.c15
1 files changed, 4 insertions, 11 deletions
diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index 81b9adb6e766..453fa5ac04ad 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -150,12 +150,12 @@ static int altera_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
} else {
- /* send the first byte */
- writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);
-
- while (1) {
+ while (hw->count < hw->len) {
unsigned int rxd;
+ writel(hw_txbyte(hw, hw->count),
+ hw->base + ALTERA_SPI_TXDATA);
+
while (!(readl(hw->base + ALTERA_SPI_STATUS) &
ALTERA_SPI_STATUS_RRDY_MSK))
cpu_relax();
@@ -174,14 +174,7 @@ static int altera_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
}
hw->count++;
-
- if (hw->count < hw->len)
- writel(hw_txbyte(hw, hw->count),
- hw->base + ALTERA_SPI_TXDATA);
- else
- break;
}
-
}
return hw->count * hw->bytes_per_word;