From 72be0ee42ebaf744d4a5cf684ee68dba59d6bac1 Mon Sep 17 00:00:00 2001 From: Axel Lin Date: Thu, 15 Aug 2013 14:18:46 +0800 Subject: [PATCH] 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 Acked-by: Thomas Chou Signed-off-by: Mark Brown --- drivers/spi/spi-altera.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c index 81b9adb..453fa5a 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; -- 2.7.4