Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 72be0ee4 authored by Axel Lin's avatar Axel Lin Committed by Mark Brown
Browse files

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: default avatarAxel Lin <axel.lin@ingics.com>
Acked-by: default avatarThomas Chou <thomas@wytron.com.tw>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent d8dfad38

drivers/spi/spi-altera.c

+4 −11
Original line number Diff line number Diff line
@@ -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;