From patchwork Fri Mar 6 09:31:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 11423431 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 536F719B6 for ; Fri, 6 Mar 2020 09:32:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CE6C20866 for ; Fri, 6 Mar 2020 09:32:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726251AbgCFJcI (ORCPT ); Fri, 6 Mar 2020 04:32:08 -0500 Received: from sauhun.de ([88.99.104.3]:55996 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726010AbgCFJcI (ORCPT ); Fri, 6 Mar 2020 04:32:08 -0500 Received: from localhost (p54B33158.dip0.t-ipconnect.de [84.179.49.88]) by pokefinder.org (Postfix) with ESMTPSA id CD2F62C1F5A; Fri, 6 Mar 2020 10:32:05 +0100 (CET) From: Wolfram Sang To: linux-mmc@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , =?utf-8?q?Niklas_S?= =?utf-8?q?=C3=B6derlund?= , Wolfram Sang Subject: [PATCH RFT 1/3] mmc: renesas_sdhi: refactor calculation of best TAP Date: Fri, 6 Mar 2020 10:31:57 +0100 Message-Id: <20200306093159.6155-2-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200306093159.6155-1-wsa+renesas@sang-engineering.com> References: <20200306093159.6155-1-wsa+renesas@sang-engineering.com> MIME-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org To select the best TAP, we need to find the longest stream of set bits in a bit field. There is now a helper function for bitmaps which iterates over all region of set bits. Using it makes the code much more concise and easier to understand. Double so, because we need to handle two bitmaps in the near future. Remove a superfluous comment while here. Signed-off-by: Wolfram Sang --- drivers/mmc/host/renesas_sdhi_core.c | 36 +++++++--------------------- 1 file changed, 8 insertions(+), 28 deletions(-) diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index df826661366f..f3ef26e29e8f 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -427,15 +427,10 @@ static int renesas_sdhi_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_io static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) { struct renesas_sdhi *priv = host_to_priv(host); - unsigned long tap_cnt; /* counter of tuning success */ - unsigned long tap_start;/* start position of tuning success */ - unsigned long tap_end; /* end position of tuning success */ - unsigned long ntap; /* temporary counter of tuning success */ - unsigned long i; + unsigned int tap_start = 0, tap_end = 0, tap_cnt = 0, rs, re, i; + unsigned int taps_size = priv->tap_num * 2; priv->doing_tune = false; - - /* Clear SCC_RVSREQ */ sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); /* @@ -443,7 +438,7 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) * result requiring the tap to be good in both runs before * considering it for tuning selection. */ - for (i = 0; i < priv->tap_num * 2; i++) { + for (i = 0; i < taps_size; i++) { int offset = priv->tap_num * (i < priv->tap_num ? 1 : -1); if (!test_bit(i, priv->taps)) @@ -455,29 +450,14 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) * is more than SH_MOBILE_SDHI_MAX_TAP probes long then use the * center index as the tap. */ - tap_cnt = 0; - ntap = 0; - tap_start = 0; - tap_end = 0; - for (i = 0; i < priv->tap_num * 2; i++) { - if (test_bit(i, priv->taps)) { - ntap++; - } else { - if (ntap > tap_cnt) { - tap_start = i - ntap; - tap_end = i - 1; - tap_cnt = ntap; - } - ntap = 0; + bitmap_for_each_set_region(priv->taps, rs, re, 0, taps_size) { + if (re - 1 - rs > tap_cnt) { + tap_end = re - 1; + tap_start = rs; + tap_cnt = tap_end - tap_start; } } - if (ntap > tap_cnt) { - tap_start = i - ntap; - tap_end = i - 1; - tap_cnt = ntap; - } - if (tap_cnt >= SH_MOBILE_SDHI_MAX_TAP) priv->tap_set = (tap_start + tap_end) / 2 % priv->tap_num; else