From patchwork Tue Aug 7 06:17:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 10558231 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2BC3C14E2 for ; Tue, 7 Aug 2018 06:18:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1AD0A297A6 for ; Tue, 7 Aug 2018 06:18:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0ECA029818; Tue, 7 Aug 2018 06:18:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ED9DB297A6 for ; Tue, 7 Aug 2018 06:18:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388360AbeHGIa6 (ORCPT ); Tue, 7 Aug 2018 04:30:58 -0400 Received: from conuserg-08.nifty.com ([210.131.2.75]:39262 "EHLO conuserg-08.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727360AbeHGIa5 (ORCPT ); Tue, 7 Aug 2018 04:30:57 -0400 Received: from pug.e01.socionext.com (p14092-ipngnfx01kyoto.kyoto.ocn.ne.jp [153.142.97.92]) (authenticated) by conuserg-08.nifty.com with ESMTP id w776HYgi009463; Tue, 7 Aug 2018 15:17:39 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-08.nifty.com w776HYgi009463 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1533622660; bh=qIOmIprJkVi21IP1uiV+8Gl0nf5/lZ12zXJKRFzTnGQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bvOcbINp7Do8Jv0JSmQkdtyqT4eT8Hj3WTQkqVa/fn3G9Pr9H3rC2ZlZD1vZRs9iR J9Z2VoY1xWLBemgUAitUi1Cc02LbLMWb7gNYFvceeEnXoF6ywpQnSgrcmjTs8XsXo5 xO3nLJqUAM+XmfIr7wJ8bgsUVr6i7PrtCONx9pc2EdrpGY3W2GqWTGbNBf7w3AnIH+ CnSLgfAY9O6EU076+YG0ssEHdizLusjDmqOU6tb5edAd5fYUXEgiNusiLJwb0iJsVz /1Sm5BrluZMDJZrNVX1EzlyZPvhW2p352Qlupx5zsnZYwVISrUf4jU3cwU/D+zOQzA aGv1IwmDezXPQ== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: Wolfram Sang , linux-mmc@vger.kernel.org Cc: Ulf Hansson , linux-renesas-soc@vger.kernel.org, Masami Hiramatsu , Jassi Brar , Masahiro Yamada , linux-kernel@vger.kernel.org Subject: [v0.1 PATCH 6/7] mmc: renesas_sdhi: refactor CLK_CTL bit calculation Date: Tue, 7 Aug 2018 15:17:21 +0900 Message-Id: <1533622642-13989-7-git-send-email-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1533622642-13989-1-git-send-email-yamada.masahiro@socionext.com> References: <1533622642-13989-1-git-send-email-yamada.masahiro@socionext.com> Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP for (clk = 0x80000080; new_clock >= (clock << 1); clk >>= 1) clock <<= 1; ... is too tricky, hence I replaced with roundup_pow_of_two(divisor) >> 2 '(clk >> 22) & 0x1' is the bit test for the 1/1 divisor, but it is not clear. 'divisor <= 1' is easier to understand. Signed-off-by: Masahiro Yamada --- drivers/mmc/host/renesas_sdhi_core.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index a15fb2e..98391e9 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -158,7 +158,8 @@ static unsigned int renesas_sdhi_clk_update(struct tmio_mmc_host *host, static void renesas_sdhi_set_clock(struct tmio_mmc_host *host, unsigned int new_clock) { - u32 clk = 0, clock; + unsigned int clock, divisor; + u32 clk = 0; sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN & sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL)); @@ -166,14 +167,18 @@ static void renesas_sdhi_set_clock(struct tmio_mmc_host *host, if (new_clock == 0) goto out; - clock = renesas_sdhi_clk_update(host, new_clock) / 512; + clock = renesas_sdhi_clk_update(host, new_clock); - for (clk = 0x80000080; new_clock >= (clock << 1); clk >>= 1) - clock <<= 1; + divisor = clock / new_clock; - /* 1/1 clock is option */ - if ((host->pdata->flags & TMIO_MMC_CLK_ACTUAL) && ((clk >> 22) & 0x1)) - clk |= 0xff; + /* + * bit7 set: 1/512, ... bit0 set:1/4, all bits clear: 1/2 + * all bits set: 1/1 (Renesas-specific extension?) + */ + if ((host->pdata->flags & TMIO_MMC_CLK_ACTUAL) && divisor <= 1) + clk = 0xff; + else + clk = roundup_pow_of_two(divisor) >> 2; sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, clk & CLK_CTL_DIV_MASK); if (!(host->pdata->flags & TMIO_MMC_MIN_RCAR2))