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 51CD3C433F5 for ; Thu, 17 Mar 2022 09:34:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232005AbiCQJff (ORCPT ); Thu, 17 Mar 2022 05:35:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53570 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230225AbiCQJfX (ORCPT ); Thu, 17 Mar 2022 05:35:23 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0512F16C0A5; Thu, 17 Mar 2022 02:33:53 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: kholk11) with ESMTPSA id 58D771F44F7A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1647509631; bh=8Er5GMCq22zzAAuQZRr5EH7rpvXOYy2RxuXWgEVIUdU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=OXQ44H9PyxXsqT7XBKE+MUrrBX6Bte9NHGf9ZYP1I3YTg0m7l7yWzXM4a6sk5h2Pc 3uySIHDN3dAo6mixFH88PgXju5IGvpvjiUQr6fj/SaT6U0k5P+wSjL/9w3UKh0ccQ4 UnSpTM3cJW7NSl6JWFz8rs+H5uC2nUArtmAVPxPT9TTmHqEeLNKCGlH+4rucCmZuQt VdQK3lJAMliqNv0Zh3eXf5mz48J2PDUm/bPqNwrMmYI0FA1Q86FvIabDuTTDriq17p 9SCS7ZG8oKJAPxPUbqvdt5W6R8zrqwmNGmpCsM24hHK/t2IHfv6LVHCIwM00WeXGzw K4G4rcZ6Z7E4Q== Message-ID: Date: Thu, 17 Mar 2022 10:33:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 Subject: Re: [PATCH V4 4/6] spi: mediatek: add spi memory support for ipm design Content-Language: en-US To: Leilk Liu , Mark Brown Cc: Rob Herring , Matthias Brugger , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org, linux-mediatek@lists.infradead.org References: <20220315032411.2826-1-leilk.liu@mediatek.com> <20220315032411.2826-5-leilk.liu@mediatek.com> <602f93f020967789eff49e2fd821d1b03f5b009f.camel@mediatek.com> From: AngeloGioacchino Del Regno In-Reply-To: <602f93f020967789eff49e2fd821d1b03f5b009f.camel@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 17/03/22 10:27, Leilk Liu ha scritto: > On Tue, 2022-03-15 at 10:31 +0100, AngeloGioacchino Del Regno wrote: >> Il 15/03/22 04:24, Leilk Liu ha scritto: >>> this patch add the support of spi-mem for ipm design. >>> >>> Signed-off-by: Leilk Liu >>> --- >>> drivers/spi/spi-mt65xx.c | 349 >>> ++++++++++++++++++++++++++++++++++++++- >>> 1 file changed, 348 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c >>> index 1a0b3208dfca..8958c3fa4fea 100644 >>> --- a/drivers/spi/spi-mt65xx.c >>> +++ b/drivers/spi/spi-mt65xx.c >> >> ...snip... >> >>> + >>> +static void of_mtk_spi_parse_dt(struct spi_master *master, struct >>> device_node *nc) >>> +{ >>> + struct mtk_spi *mdata = spi_master_get_devdata(master); >>> + u32 value; >>> + >>> + if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) { >> >> Hello Leilk, >> >> thanks for considering my advice about "spi-{tx,rx}-bus-width", but >> there's >> something that you have misunderstood about it. >> >> Simply, you don't need this function at all. Whatever you are doing >> here is >> already being performed in the Linux SPI framework: at the end of the >> probe >> function, this driver is calling the (legacy) >> devm_spi_register_master(), >> which calls devm_spi_register_controller(). >> >> In drivers/spi/spi.c, function spi_register_controller(), will in >> turn call >> of_register_spi_devices(ctlr) -> of_register_spi_device(ctlr, nc)... >> that >> will end up finally calling function of_spi_parse_dt(ctlr, spi, nc). >> >> The last mentioned function already contains the logic and setup to >> check >> devicetree properties "spi-tx-bus-width" and "spi-rx-bus-width" (and >> some >> others, as well). >> >> This means that spi-mt65xx.c already probed these even before your >> IPM >> implementation, hence ***function of_mtk_spi_parse_dt() is not >> needed***. >> >> Simply drop it and don't check for these properties: that's already >> done. >> >> >> Regards, >> Angelo >> > Hi Angelo, > > Thanks for your advice. > > There are two spi controllor on MT7986. One supports single/dual mode, > the other supports quad mode. Both of them can support spi memory > framework(one's tx/rx bus width is 1/2, the other one's tx/rx bus width > is 1/2/4). > > Can I use of_mtk_spi_parse_dt() to parse the information? What's your > suggestion? > > Thanks! > As I've already said, this does NOT require any devicetree handling in spi-mt65xx.c, as setting the right mode_bits is already handled in drivers/spi/spi.c - please follow the explaination that I have given before to fully understand the situation. Regards, Angelo > >>> + switch (value) { >>> + case 1: >>> + break; >>> + case 2: >>> + master->mode_bits |= SPI_TX_DUAL; >>> + break; >>> + case 4: >>> + master->mode_bits |= SPI_TX_QUAD; >>> + break; >>> + default: >>> + dev_warn(mdata->dev, >>> + "spi-tx-bus-width %d not supported\n", >>> + value); >>> + break; >>> + } >>> + } >>> + >>> + if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) { >>> + switch (value) { >>> + case 1: