From: "Tim Kuo" <Tim.Kuo@mediatek.com>

Mediatek SPI hardware natively supports dual and quad modes, and these
modes are already enabled for SPI flash devices under spi-mem framework
in MTK SPI controller spi-mt65xx. However, other SPI devices, such as
touch panels, are limited to single mode because spi-mt65xx lacks SPI
mode argument parsing from SPI framework for these SPI devices outside
spi-mem framework.

This patch adds dual and quad mode support for these SPI devices by
introducing a new API, mtk_spi_set_nbits, for SPI mode argument parsing.

Signed-off-by: Tim Kuo <Tim.Kuo@mediatek.com>
---
v2: remove ret and change to use fallthrough in switch

 drivers/spi/spi-mt65xx.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 8a3c00c3af42..4b40985af1ea 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -563,6 +563,22 @@ static void mtk_spi_setup_packet(struct spi_controller *host)
 	writel(reg_val, mdata->base + SPI_CFG1_REG);
 }
 
+inline u32 mtk_spi_set_nbit(u32 nbit)
+{
+	switch (nbit) {
+	default:
+		pr_warn_once("unknown nbit mode %u. Falling back to single mode\n",
+			     nbit);
+		fallthrough;
+	case SPI_NBITS_SINGLE:
+		return 0x0;
+	case SPI_NBITS_DUAL:
+		return 0x1;
+	case SPI_NBITS_QUAD:
+		return 0x2;
+	}
+}
+
 static void mtk_spi_enable_transfer(struct spi_controller *host)
 {
 	u32 cmd;
@@ -729,10 +745,16 @@ static int mtk_spi_transfer_one(struct spi_controller *host,
 
 	/* prepare xfer direction and duplex mode */
 	if (mdata->dev_comp->ipm_design) {
-		if (!xfer->tx_buf || !xfer->rx_buf) {
+		if (xfer->tx_buf && xfer->rx_buf) {
+			reg_val &= ~SPI_CFG3_IPM_HALF_DUPLEX_EN;
+		} else if (xfer->tx_buf) {
+			reg_val |= SPI_CFG3_IPM_HALF_DUPLEX_EN;
+			reg_val &= ~SPI_CFG3_IPM_HALF_DUPLEX_DIR;
+			reg_val |= mtk_spi_set_nbit(xfer->tx_nbits);
+		} else {
 			reg_val |= SPI_CFG3_IPM_HALF_DUPLEX_EN;
-			if (xfer->rx_buf)
-				reg_val |= SPI_CFG3_IPM_HALF_DUPLEX_DIR;
+			reg_val |= SPI_CFG3_IPM_HALF_DUPLEX_DIR;
+			reg_val |= mtk_spi_set_nbit(xfer->rx_nbits);
 		}
 		writel(reg_val, mdata->base + SPI_CFG3_IPM_REG);
 	}
-- 
2.45.2

On Wed, 17 Sep 2025 13:58:39 +0800, Tim Kuo wrote:
> Mediatek SPI hardware natively supports dual and quad modes, and these
> modes are already enabled for SPI flash devices under spi-mem framework
> in MTK SPI controller spi-mt65xx. However, other SPI devices, such as
> touch panels, are limited to single mode because spi-mt65xx lacks SPI
> mode argument parsing from SPI framework for these SPI devices outside
> spi-mem framework.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: mt65xx: add dual and quad mode for standard spi device
      commit: ab63e9910d2d3ea4b8e6c08812258a676defcb9c

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Il 17/09/25 07:58, Tim Kuo ha scritto:
> From: "Tim Kuo" <Tim.Kuo@mediatek.com>
> 
> Mediatek SPI hardware natively supports dual and quad modes, and these
> modes are already enabled for SPI flash devices under spi-mem framework
> in MTK SPI controller spi-mt65xx. However, other SPI devices, such as
> touch panels, are limited to single mode because spi-mt65xx lacks SPI
> mode argument parsing from SPI framework for these SPI devices outside
> spi-mem framework.
> 
> This patch adds dual and quad mode support for these SPI devices by
> introducing a new API, mtk_spi_set_nbits, for SPI mode argument parsing.
> 
> Signed-off-by: Tim Kuo <Tim.Kuo@mediatek.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>