spi: altera: Simplify altera_spi_txrx implementation for noirq case (72be0ee4) · Commits · 戴 / test

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>

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;

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