Re: [PATCH 2/2] spi: qcom-geni: Add property to force GSI mode

[Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>]

On 6/14/2026 2:04 PM, Pengyu Luo wrote:
> Some devices (such as gaokun3) do not disable FIFO mode, causing the
> driver to fallback to FIFO mode by default. However, these platforms
> also support GSI mode, which is highly preferred for certain
> peripherals like SPI touchscreens to improve performance.
> 
> Introduce the "qcom,force-gsi-mode" device property to hint and force
> the controller into GSI mode during initialization.
> 
> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> ---
>   drivers/spi/spi-geni-qcom.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
> index 26e723cfea61..eece7312f780 100644
> --- a/drivers/spi/spi-geni-qcom.c
> +++ b/drivers/spi/spi-geni-qcom.c
> @@ -102,6 +102,7 @@ struct spi_geni_master {
>   	int irq;
>   	bool cs_flag;
>   	bool abort_failed;
> +	bool force_gsi_mode;
>   	struct dma_chan *tx;
>   	struct dma_chan *rx;
>   	int cur_xfer_mode;
> @@ -655,6 +656,9 @@ static int spi_geni_init(struct spi_geni_master *mas)
>   		mas->oversampling = 1;
>   
>   	fifo_disable = readl(se->base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;
> +	if (mas->force_gsi_mode)
> +		fifo_disable = 1;
> +
>   	switch (fifo_disable) {
>   	case 1:
>   		ret = spi_geni_grab_gpi_chan(mas);
> @@ -1133,6 +1137,9 @@ static int spi_geni_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
>   
> +	if (device_property_read_bool(&pdev->dev, "qcom,force-gsi-mode"))
> +		mas->force_gsi_mode = true;
> +
I don't think this is a HW bit, it's an internal selection based on FW 
programming. This is inherently decided by GENI_IF_DISABLE_RO, No 
exposure to the user/DT.
>   	ret = spi_geni_init(mas);
>   	if (ret)
>   		return ret;