From 14ac4e049dc1183440960f177b60b54357e54d90 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Sat, 12 Sep 2020 14:08:00 -0700 Subject: [PATCH] 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: Douglas Anderson Reviewed-by: Bjorn Andersson Link: https://lore.kernel.org/r/20200912140730.2.I33e571179986850b4ec17042e813d0b08fb1b9c1@changeid Signed-off-by: Mark Brown --- drivers/spi/spi-geni-qcom.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c index 7f0bf0d..92d88bf 100644 --- a/drivers/spi/spi-geni-qcom.c +++ b/drivers/spi/spi-geni-qcom.c @@ -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 -- 2.7.4