Unverified Commit 14ac4e04 authored by Douglas Anderson's avatar Douglas Anderson Committed by Mark Brown
Browse files

spi: spi-geni-qcom: Don't program CS_TOGGLE again and again 



We always toggle the chip select manually in spi-geni-qcom so that we
can properly implement the Linux API.  There's no reason to program
this to the hardware on every transfer.  Program it once at init and
be done with it.

This saves some part of a microsecond of overhead on each transfer.
While not really noticeable on any real world benchmarks, we might as
well save the time.

Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Reviewed-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20200912140730.2.I33e571179986850b4ec17042e813d0b08fb1b9c1@changeid


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent fc129a43

drivers/spi/spi-geni-qcom.c

+7 −5
Original line number Diff line number Diff line
@@ -290,6 +290,7 @@ static int spi_geni_init(struct spi_geni_master *mas) 
{

	struct geni_se *se = &mas->se;

	unsigned int proto, major, minor, ver;

	u32 spi_tx_cfg;



	pm_runtime_get_sync(mas->dev);
@@ -322,6 +323,11 @@ static int spi_geni_init(struct spi_geni_master *mas) 


	geni_se_select_mode(se, GENI_SE_FIFO);



	/* We always control CS manually */

	spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);

	spi_tx_cfg &= ~CS_TOGGLE;

	writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);



	pm_runtime_put(mas->dev);

	return 0;

}
@@ -331,7 +337,7 @@ static void setup_fifo_xfer(struct spi_transfer *xfer, 
				u16 mode, struct spi_master *spi)

{

	u32 m_cmd = 0;

	u32 spi_tx_cfg, len;

	u32 len;

	struct geni_se *se = &mas->se;

	int ret;
@@ -350,7 +356,6 @@ static void setup_fifo_xfer(struct spi_transfer *xfer, 
	spin_lock_irq(&mas->lock);

	spin_unlock_irq(&mas->lock);



	spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);

	if (xfer->bits_per_word != mas->cur_bits_per_word) {

		spi_setup_word_len(mas, mode, xfer->bits_per_word);

		mas->cur_bits_per_word = xfer->bits_per_word;
@@ -364,8 +369,6 @@ static void setup_fifo_xfer(struct spi_transfer *xfer, 
	mas->tx_rem_bytes = 0;

	mas->rx_rem_bytes = 0;



	spi_tx_cfg &= ~CS_TOGGLE;



	if (!(mas->cur_bits_per_word % MIN_WORD_LEN))

		len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word;

	else
@@ -384,7 +387,6 @@ static void setup_fifo_xfer(struct spi_transfer *xfer, 
		writel(len, se->base + SE_SPI_RX_TRANS_LEN);

		mas->rx_rem_bytes = xfer->len;

	}

	writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);



	/*

	 * Lock around right before we start the transfer since our