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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7A72EB64D9 for ; Mon, 10 Jul 2023 14:38:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233296AbjGJOi3 (ORCPT ); Mon, 10 Jul 2023 10:38:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229793AbjGJOi1 (ORCPT ); Mon, 10 Jul 2023 10:38:27 -0400 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41C69D7 for ; Mon, 10 Jul 2023 07:38:26 -0700 (PDT) Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 36AEcCfW064353; Mon, 10 Jul 2023 09:38:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1688999892; bh=+NyYiBIVfky5FyHiALbxif/2d8M8ji1PBrAZbcEWnkY=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=E0wKacmcy7Mvj34IuYLm3FNU+/mijt0hVPjXqhzW6Anbp3aUSE95p+pJW4wqQFJkI +fd5/S+5WmgUVefv8szEb58hWZx+r+zti33+lMhZ7FFil15JiDP2QZI4TlweWTjIje 06kU4u8UqwLjMfnkv1Bc8tMCiIcmKioJsV4F5c/s= Received: from DLEE100.ent.ti.com (dlee100.ent.ti.com [157.170.170.30]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 36AEcC3W011931 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 10 Jul 2023 09:38:12 -0500 Received: from DLEE107.ent.ti.com (157.170.170.37) by DLEE100.ent.ti.com (157.170.170.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Mon, 10 Jul 2023 09:38:12 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DLEE107.ent.ti.com (157.170.170.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Mon, 10 Jul 2023 09:38:12 -0500 Received: from [10.250.32.50] (ileaxei01-snat.itg.ti.com [10.180.69.5]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 36AEcBeq042221; Mon, 10 Jul 2023 09:38:12 -0500 Message-ID: <693d7d42-b062-1e01-b920-e13c2d08ca6f@ti.com> Date: Mon, 10 Jul 2023 09:38:11 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH] phy: ti: gmii-sel: Allow parent to not be syscon node To: Siddharth Vadapalli CC: Vinod Koul , Kishon Vijay Abraham I , Roger Quadros , , References: <20230515195922.617243-1-afd@ti.com> <5ae4bd37-65ee-d6da-1ab6-c1018d9959ec@ti.com> Content-Language: en-US From: Andrew Davis In-Reply-To: <5ae4bd37-65ee-d6da-1ab6-c1018d9959ec@ti.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/15/23 11:05 PM, Siddharth Vadapalli wrote: > Andrew, > > On 16/05/23 01:29, Andrew Davis wrote: >> If the parent node is not a syscon type, then fallback and check >> if we can get a regmap from our own node. This no longer forces >> us to make the parent of this node a syscon node when that might >> not be appropriate. > > Could you please let me know in which cases it is appropriate versus in which > cases it isn't? Use of syscon nodes should be discouraged, in most cases they can and should be avoided. The only time we would need to have a syscon parent is when the register space contains multiple sub-devices with bit level interleaving. Most devices should never need syscon, we overuse syscon due to driver like this that have no other option than to make the parent device a syscon node. > Is syscon_node_to_regmap() being retained for backward > compatibility until the device-tree nodes are cleaned up across all devices? > Yes, the old way is left only for backwards compatibility. >> >> Signed-off-by: Andrew Davis >> --- >> drivers/phy/ti/phy-gmii-sel.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/phy/ti/phy-gmii-sel.c b/drivers/phy/ti/phy-gmii-sel.c >> index 8c667819c39a..1e67ed9a5cf6 100644 >> --- a/drivers/phy/ti/phy-gmii-sel.c >> +++ b/drivers/phy/ti/phy-gmii-sel.c >> @@ -435,9 +435,12 @@ static int phy_gmii_sel_probe(struct platform_device *pdev) >> >> priv->regmap = syscon_node_to_regmap(node->parent); >> if (IS_ERR(priv->regmap)) { >> - ret = PTR_ERR(priv->regmap); >> - dev_err(dev, "Failed to get syscon %d\n", ret); >> - return ret; >> + priv->regmap = device_node_to_regmap(node); > > If device_node_to_regmap() can always be used with the corresponding changes > made to the device-tree nodes, wouldn't it be better to use it directly instead > of using it as a fallback? (This is based on the assumption that > syscon_node_to_regmap() is only being retained until the device-tree nodes are > cleaned up to work with device_node_to_regmap()). > Yes, that could work too. I was trying to make the minimal changes here, but if we feel it works better we can have the default be to check the self node first. Andrew >> + if (IS_ERR(priv->regmap)) { >> + ret = PTR_ERR(priv->regmap); >> + dev_err(dev, "Failed to get syscon %d\n", ret); >> + return ret; >> + } >> } >> >> ret = phy_gmii_sel_init_ports(priv); >