Re: [Patch V6 2/3] tpm_tis-spi: Support hardware wait polling

[Thierry Reding <thierry.reding@gmail.com>]

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On Mon, Feb 27, 2023 at 10:51:07PM +0530, Krishna Yarlagadda wrote:
[...]
> diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
[...]
> @@ -140,6 +206,28 @@ int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
>  	return ret;
>  }
>  
> +int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
> +			 u8 *in, const u8 *out)
> +{
> +	struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
> +	struct spi_controller *ctlr = phy->spi_device->controller;
> +
> +	/*
> +	 * TPM flow control over SPI requires full duplex support.
> +	 * Send entire message to a half duplex controller to handle
> +	 * wait polling in controller.
> +	 * Set TPM HW flow control flag..
> +	 */
> +	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) {
> +		phy->spi_device->mode |= SPI_TPM_HW_FLOW;

Can this be pushed up to tpm_tis_spi_probe()? The SPI controller flags
are fixed, so this isn't going to change at runtime, is it?

Thierry

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