From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7F038C433EF for ; Fri, 18 Mar 2022 08:50:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Reply-To:Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date :Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=BMKGNun+FhohqpV3MfbemreiS3pzGsOTZ9VA2sQYc5E=; b=CGwR2mlmGWuyt9sqfxLg3ikRPl YPsgyyCnSleMFf/wNjiMDh3lyKZJRIsv52AjBRNHB/yylDK1ySIWY+6cplHiyWDSDwt4JU6/qIael K2wICCYBHLgZxial0nh4Hx/+uoLNOTp9dYhadkHqozbvQqD4uFdPZ4vUW0LUYRxIwhh+aEt5yk+Ao xSX5NuSxBeLnZvy0Zwq1gOzU9aFhOy+zkU9WTTALiL3TaEHLhO1WW27mADH3zy1o+iHak/v3wy3zm PPlRIXzUBA9jo1q1EUQUlKfmOqSc3oO8USOhTBvoUr1A9rZH1X+YQXB3oTOxhYOBzyP+zSMlRtCBS PtaXHhqg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nV8IN-000s0k-8S; Fri, 18 Mar 2022 08:49:15 +0000 Received: from relay4-d.mail.gandi.net ([2001:4b98:dc4:8::224]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nV8II-000rza-L0 for linux-arm-kernel@lists.infradead.org; Fri, 18 Mar 2022 08:49:13 +0000 Received: (Authenticated sender: paul.kocialkowski@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id BEAB7E000F; Fri, 18 Mar 2022 08:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1647593347; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+bAdKA3T8fJldt3bCutW94XcxG9KeQUgHALYsG5O6TU=; b=J2tzoyCplqZnwfh5iT0yGbxyzZ4hKWazmRtP0vBd5WrBzslQy+Dz8PTvY5rkJeAhvZFtkx zqjqeqWA/gq+LKAJTIetLiGCTVURg29P1UqocB+FR4DgXcYZZJXGRnGAq/wB2EMb1CA363 8Jaij9mhCFhI+LIszpmzbhRXPuFvBXPdPSZSOs6pUik4gopQBdyZI51TdhbCa96sKfrwAo 1Ndv/NaU+1Mlq3IB9G+v3ohL9DemGHyhBedEXyhcxROhGSwpx2z2v6MdgbPo2qc1/DGEsN BIa+nP7a/rJFf2E/Ms+cU5Zn+KQk4ff4Ybfc7L0E6YBs+gI3VrhAG/LdqrYyQA== Date: Fri, 18 Mar 2022 09:49:04 +0100 From: Paul Kocialkowski To: Jernej =?utf-8?Q?=C5=A0krabec?= Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, Yong Deng , Mauro Carvalho Chehab , Chen-Yu Tsai , Samuel Holland , Laurent Pinchart , Maxime Ripard , Thomas Petazzoni Subject: Re: [PATCH v3 03/46] media: sun6i-csi: Grab bus clock instead of passing it to regmap Message-ID: References: <20220311143532.265091-1-paul.kocialkowski@bootlin.com> <20220311143532.265091-4-paul.kocialkowski@bootlin.com> <2361247.jE0xQCEvom@kista> MIME-Version: 1.0 In-Reply-To: <2361247.jE0xQCEvom@kista> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220318_014911_365619_8BC956E7 X-CRM114-Status: GOOD ( 24.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============6105453947740603180==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============6105453947740603180== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="gHLgdwLJSCzaTAAW" Content-Disposition: inline --gHLgdwLJSCzaTAAW Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Jernej, On Tue 15 Mar 22, 20:22, Jernej =C5=A0krabec wrote: > Hi Paul! >=20 > Dne petek, 11. marec 2022 ob 15:34:49 CET je Paul Kocialkowski napisal(a): > > Since the bus clock alone is not enough to get access to the registers, > > don't pass it to regmap and manage it instead just like the other > > clocks. > >=20 >=20 > Let me ask it in another way, is bus clock needed only for register acces= s? If=20 > yes, it makes sense to keep it enabled only during register access. Ah right, I lost sight that what regmap will do is to enable/disable the clock around register access. I understand there might be an advantage in terms of power consumption here. I haven't checked specifically, but since it was used like that before it's probably fine. Out of curiosity: is there any noticeable latency added by the process? Cheers, Paul > Best regards, > Jernej >=20 > > Signed-off-by: Paul Kocialkowski > > --- > > drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 10 ++++++++-- > > drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h | 1 + > > 2 files changed, 9 insertions(+), 2 deletions(-) > >=20 > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drive= rs/ > media/platform/sunxi/sun6i-csi/sun6i_csi.c > > index 5fbaa1e99412..dc79f3c14336 100644 > > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > > @@ -827,13 +827,19 @@ static int sun6i_csi_resource_request(struct=20 > sun6i_csi_device *csi_dev, > > if (IS_ERR(io_base)) > > return PTR_ERR(io_base); > > =20 > > - csi_dev->regmap =3D devm_regmap_init_mmio_clk(&pdev->dev, "bus",=20 > io_base, > > - =20 > &sun6i_csi_regmap_config); > > + csi_dev->regmap =3D devm_regmap_init_mmio(&pdev->dev, io_base, > > + =09 > &sun6i_csi_regmap_config); > > if (IS_ERR(csi_dev->regmap)) { > > dev_err(&pdev->dev, "Failed to init register map\n"); > > return PTR_ERR(csi_dev->regmap); > > } > > =20 > > + csi_dev->clk_bus =3D devm_clk_get(&pdev->dev, "bus"); > > + if (IS_ERR(csi_dev->clk_bus)) { > > + dev_err(&pdev->dev, "Unable to acquire bus clock\n"); > > + return PTR_ERR(csi_dev->clk_bus); > > + } > > + > > csi_dev->clk_mod =3D devm_clk_get(&pdev->dev, "mod"); > > if (IS_ERR(csi_dev->clk_mod)) { > > dev_err(&pdev->dev, "Unable to acquire csi clock\n"); > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drive= rs/ > media/platform/sunxi/sun6i-csi/sun6i_csi.h > > index e4e7ac6c869f..356661b413f8 100644 > > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h > > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h > > @@ -51,6 +51,7 @@ struct sun6i_csi_device { > > struct sun6i_video video; > > =20 > > struct regmap *regmap; > > + struct clk *clk_bus; > > struct clk *clk_mod; > > struct clk *clk_ram; > > struct reset_control *reset; > > --=20 > > 2.35.1 > >=20 > >=20 >=20 >=20 --=20 Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com --gHLgdwLJSCzaTAAW Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEJZpWjZeIetVBefti3cLmz3+fv9EFAmI0R4AACgkQ3cLmz3+f v9HeVQf8CKT1qm0Afb3D5ftaWSjBnvSaPjI1zrK0d267DdUOAMWvOOJp+8dLNx+b 7y2dlj+4zVD8nIcixvmVJ5hR2APgzgz/lgiUnYBQa9EmU2fFufSbEx3ugT2+rkGr fOVtDhbGob1l3Es0HNTYFWOSTOu9uUsudlEGr+WazSJzTy6KD4wkc+osin8uGfMs 7FVkADgg0MQn4svLRLpnL6/GJtFSh2jkiaHquket6AwoztJgOOMmETmUDq+Y1dWc rDOSI9emIa3I5lmO2/vkFOS/rTR1G4J2gkPqw3jOyW0lV+GrJ9O0cOQRQoRBwcjF 9r3tjFy6ReRRxfFVHKFe9Jko7mftCg== =txhr -----END PGP SIGNATURE----- --gHLgdwLJSCzaTAAW-- --===============6105453947740603180== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============6105453947740603180==--