From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82B8B1C701C; Wed, 26 Mar 2025 13:04:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742994270; cv=none; b=tHQQr9pg49wPtO1mg8RdY7Zn6QxBIvUdUjdF4iK8tmciiMukdzIQwAPRWARyOZCCrzqdzbHeXWdt+oGzhVmeN9ZdpNN1/DKA8UY255W1lbuA4M/bYTiab8iFIUymFA43KdqK/6ujOqjgf8yT/beHC9BGs18T64dv4y6q/eRGAOg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742994270; c=relaxed/simple; bh=KDANuWDZlRVtR6lwucYZCGj0Psq7ZuBgCEMzfQRPj8Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PK2mSKTdrk2StgMPSsA2UBno7Kh1ro++83AqTi2dhaUY0UV1+p8Pmqwgv9kkbUa2oCqnSpG7G5frUDKVDZ6i77Mr+NdeKBXJEjIqip3vfAnIokY0ZqhBAq26wWpf1PF/CsnT6A5wxS8yDadWHlfGDqgE/NoOmmUDIPM4CDp/Hms= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nRh4OKmc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nRh4OKmc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0A12C4CEE2; Wed, 26 Mar 2025 13:04:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742994270; bh=KDANuWDZlRVtR6lwucYZCGj0Psq7ZuBgCEMzfQRPj8Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nRh4OKmctbtFdVLYbdRm+XzAtVN4zENUm+iHGX4Jn4Y9XLM9+QctbzlZkwUuMjB7j d5hEev0amv694c4xTzeQXaZMRaI6HZQTxJOdddkyrvjpmsyRSrDfbPI4++IEnCB1zM UWc8yNaytz+5ZreTtZM7kz8LOApt3g0SGKSnNarV0/DzKK5pkJezRemzItKFUjvwmO a6Qs/q76n3k7va4WK9vkVa4hfhO8Ok/KDa3GLC8mUu2oHPs5Ow7iB3FdnCENNsgW0G QuwC/6BeCCOJEfi3KxmuqjFwYTlS4KAYtuHJMoPa1mwc2ONTGXZUvLOMfb4RRHkRTr 6UHBG/zHXmBYw== Date: Wed, 26 Mar 2025 13:04:26 +0000 From: Mark Brown To: Mukesh Kumar Savaliya Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, andersson@kernel.org, konradybcio@kernel.org Subject: Re: [PATCH V1] spi: Add support for Double Transfer Rate (DTR) mode Message-ID: <40db39ef-7ef3-4720-9c85-ccfe1c11c299@sirena.org.uk> References: <20250326083954.3338597-1-quic_msavaliy@quicinc.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="qd8pf4HPEhmM3qAr" Content-Disposition: inline In-Reply-To: <20250326083954.3338597-1-quic_msavaliy@quicinc.com> X-Cookie: To err is humor. --qd8pf4HPEhmM3qAr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Mar 26, 2025 at 02:09:54PM +0530, Mukesh Kumar Savaliya wrote: > This change introduces a new field `dtr_mode` in the `spi_transfer` > structure. The `dtr_mode` field allows protocol drivers to indicate if > Double Transfer Rate (DTR) mode is supported for a given transfer. When > `dtr_mode` is set to true, the SPI controller will use DTR mode > otherwise, it will default to single transfer mode. > The QSPI controller driver uses this flag and configures single or double > transfer rate using the controller register. We should have a flag in the controller indicating if it supports this, and code in the core which returns an error if a driver attempts to use it when the controller doesn't support it. --qd8pf4HPEhmM3qAr Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmfj+1kACgkQJNaLcl1U h9DJQAf/YJ+ojB+devzgPrAXauOe46juaTWouRZEJJh1yRZj/wGvASS+XzaM+7Op 1JnoQDosb0Ig8+MfNIzVInw19R1kRjiDL9ZdybDp5U3phlna86Wqdns+Q93qS3Uk HfJptnAFS9VsJhguL7sZ3Ki7okwteN4r9/SAvr2y6Ag1TOugrtR0DvFW0HBTR29Y Ljjd72DDZXOFDk7EiRorjE/Afl1gGUiAzNPbYoub0n/5DNk9Z/QolKCNBFINZKfM xfZOpYpGH5BAbrRjE5AT6VihV4k+2MzJfHFPcr1+sOD78xv1D+l55I1tU8UBR18Y M3Q7mVyxyM+fQhLJ+Vy9mDa5b8Errw== =eDGt -----END PGP SIGNATURE----- --qd8pf4HPEhmM3qAr--