Date:   Wed, 1 Mar 2023 14:37:45 +0100
From:   Thierry Reding <thierry.reding@gmail.com>
To:     Krishna Yarlagadda <kyarlagadda@nvidia.com>
Cc:     robh+dt@kernel.org, broonie@kernel.org, peterhuewe@gmx.de,
        jgg@ziepe.ca, jarkko@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        linux-spi@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        jonathanh@nvidia.com, skomatineni@nvidia.com, ldewangan@nvidia.com
Subject: Re: [Patch V6 2/3] tpm_tis-spi: Support hardware wait polling
Message-ID: <Y/9VKV6ddpWlmU9f@orome>
References: <20230227172108.8206-1-kyarlagadda@nvidia.com>
 <20230227172108.8206-3-kyarlagadda@nvidia.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_t=
is_spi_main.c
[...]
> @@ -140,6 +206,28 @@ int tpm_tis_spi_transfer(struct tpm_tis_data *data, =
u32 addr, u16 len,
>  	return ret;
>  }
> =20
> +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 =3D to_tpm_tis_spi_phy(data);
> +	struct spi_controller *ctlr =3D 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 |=3D 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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