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 3A689D2FB; Sun, 18 May 2025 07:41:39 +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=1747554100; cv=none; b=MJAQ5O6aglqxHHPUd3RsV+/HLDy/dLyAltQL3fD4LQFH+OCfdlcfcYCMzAivHmM6jWWLjA2KOhtkUVBbM1LQ+5Q3c1MAEpBFfq40GQaCKMVjrgsZSgS87TvsCxKZXzaIHEiUDMnYP4TQ3usQXqkwxlxVPdUv6sKr9LfErwZGIMI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747554100; c=relaxed/simple; bh=AHAwzXBAnTp88J/0aYWfanpi1Ub+Fzwmq0oMxgOjE18=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pLZYnhiqpaY//+rty4+LXMis0KtaGqtaGHIt94NqPGEwpxG0BaEqvZMTrRWcuumanJztIECgAYr/Kc2lvP2ja5JkYePfpxviAXi7RcRbaLAdOC4tI7r3Ob7HVxjKpk3vQDDE4ntunMKnJMyqjs0+e61OplXtpGvPRwwgqVCzFRc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uhcg1tpw; 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="uhcg1tpw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74234C4CEE7; Sun, 18 May 2025 07:41:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747554099; bh=AHAwzXBAnTp88J/0aYWfanpi1Ub+Fzwmq0oMxgOjE18=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uhcg1tpwj28HVLQcJ0DPOi/La9tamrh21D3DiZmOBN872Lec2tPGsNDK4EEQsODE+ DNyK2ZPmM9lCGXzpRS+NmSOBdi3uT6Oclzg4GwoGglOpxwRD4J3DxIqUBInkdz+fSp qWNBrdwc/8WcA464+En/fqJ9aD4KyzrcfB7h2unt1hPyT5cFTKTFKKYHvPa6Yrlv2P w22z4TpxnqQZyMIYdm7NH1ez3ZqWuiW+jGNEM/Hoon67SM9y3VVA3JZ5nWEsQEtdip NJdagNLvNgukzO9jaRFMzixZNP7Y8rCr9bbwel5x7j0zEfmOnZ0eiut/eei4Cy1NgA /iG+ncIAMuLxw== Date: Sun, 18 May 2025 16:41:34 +0900 From: William Breathitt Gray To: Dharma Balasubiramani Cc: Kamel Bouhara , linux-arm-kernel@lists.infradead.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] counter: microchip-tcb-capture: Add watch validation support Message-ID: References: <20250515-counter-tcb-v1-1-e547061ed80f@microchip.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="TSzCOtGHpFOIyFHN" Content-Disposition: inline In-Reply-To: <20250515-counter-tcb-v1-1-e547061ed80f@microchip.com> --TSzCOtGHpFOIyFHN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 15, 2025 at 10:28:25AM +0530, Dharma Balasubiramani wrote: > Introduce a watch validation callback to restrict supported event and > channel combinations. This allows userspace to receive notifications only > for valid event types and sources. Specifically, enable the following > supported events on channels RA, RB, and RC: >=20 > - COUNTER_EVENT_CAPTURE > - COUNTER_EVENT_CHANGE_OF_STATE > - COUNTER_EVENT_OVERFLOW > - COUNTER_EVENT_THRESHOLD >=20 > Signed-off-by: Dharma Balasubiramani > --- > drivers/counter/microchip-tcb-capture.c | 28 +++++++++++++++++++++++++--- > 1 file changed, 25 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/mi= crochip-tcb-capture.c > index 1de3c50b9804..179ff5595143 100644 > --- a/drivers/counter/microchip-tcb-capture.c > +++ b/drivers/counter/microchip-tcb-capture.c > @@ -337,6 +337,27 @@ static struct counter_comp mchp_tc_count_ext[] =3D { > COUNTER_COMP_COMPARE(mchp_tc_count_compare_read, mchp_tc_count_compare_= write), > }; >=20 > +static int mchp_tc_watch_validate(struct counter_device *counter, > + const struct counter_watch *watch) > +{ > + switch (watch->channel) { > + case COUNTER_MCHP_EVCHN_RA: > + case COUNTER_MCHP_EVCHN_RB: > + case COUNTER_MCHP_EVCHN_RC: Hello Dharma, Include COUNTER_MCHP_EVCHN_CV as well for the sake of completeness. I know COUNTER_MCHP_EVCHN_CV and COUNTER_MCHP_EVCHN_RA have the same underlying channel id, but we're abstracting this fact so it's good to maintain the consistency of the abstraction across all callbacks. > + switch (watch->event) { > + case COUNTER_EVENT_CAPTURE: > + case COUNTER_EVENT_CHANGE_OF_STATE: > + case COUNTER_EVENT_OVERFLOW: > + case COUNTER_EVENT_THRESHOLD: > + return 0; The watch_validate callback is used to ensure that the requested watch configuration is valid: i.e. the watch event is appropriate for the watch channel.=20 Looking at include/uapi/linux/counter/microchip-tcb-capture.h: * Channel 0: * - CV register changed * - CV overflowed * - RA captured * Channel 1: * - RB captured * Channel 2: * - RC compare triggered If I'm understanding correctly, channel 0 supports only the CHANGE_OF_STATE, OVERFLOW, and CAPTURE events; channel 1 supports only CAPTURE events; and channel 2 supports only THRESHOLD events. Adjust the code to ensure those limitations. > + default: > + return -EINVAL; > + } > + default: > + return -EINVAL; > + } > +} > + > static struct counter_count mchp_tc_counts[] =3D { > { > .id =3D 0, > @@ -351,12 +372,13 @@ static struct counter_count mchp_tc_counts[] =3D { > }; >=20 > static const struct counter_ops mchp_tc_ops =3D { > - .signal_read =3D mchp_tc_count_signal_read, > + .action_read =3D mchp_tc_count_action_read, > + .action_write =3D mchp_tc_count_action_write, > .count_read =3D mchp_tc_count_read, > .function_read =3D mchp_tc_count_function_read, > .function_write =3D mchp_tc_count_function_write, > - .action_read =3D mchp_tc_count_action_read, > - .action_write =3D mchp_tc_count_action_write > + .signal_read =3D mchp_tc_count_signal_read, It's nice to alphabetize the counter_ops callbacks, but it's also unrelated to the watch_validate implementation. Move the alphabetization cleanup to a separate patch so that this patch remains dedicated to just watch_validate changes. Thanks, William Breathitt Gray --TSzCOtGHpFOIyFHN Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQSNN83d4NIlKPjon7a1SFbKvhIjKwUCaCmPLgAKCRC1SFbKvhIj K/U6AP9sLI94pWH9oxJ5ojO2ldb52ppFei+ym7sypqbu+AOh9QD/Xqg8FFHAJS9e RltMKxTbESVr1UyIV3cfgwTc/eZ3sAw= =0BaO -----END PGP SIGNATURE----- --TSzCOtGHpFOIyFHN--