From patchwork Wed Apr 8 09:46:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 11479715 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 913061951 for ; Wed, 8 Apr 2020 09:46:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79EC320771 for ; Wed, 8 Apr 2020 09:46:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727079AbgDHJqx (ORCPT ); Wed, 8 Apr 2020 05:46:53 -0400 Received: from sauhun.de ([88.99.104.3]:39658 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727192AbgDHJqw (ORCPT ); Wed, 8 Apr 2020 05:46:52 -0400 Received: from localhost (p54B334FE.dip0.t-ipconnect.de [84.179.52.254]) by pokefinder.org (Postfix) with ESMTPSA id 420FF2C1FDD; Wed, 8 Apr 2020 11:46:51 +0200 (CEST) From: Wolfram Sang To: linux-mmc@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , Wolfram Sang , Masaharu Hayakawa , Takeshi Saito Subject: [PATCH v2 3/3] mmc: renesas_sdhi: improve TAP selection if all TAPs are good Date: Wed, 8 Apr 2020 11:46:38 +0200 Message-Id: <20200408094638.10375-4-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200408094638.10375-1-wsa+renesas@sang-engineering.com> References: <20200408094638.10375-1-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 When tuning HS400, if all TAPS are good, we can utilize the SMPCMP register to select the optimal TAP. For that, we populate a second bitmap with SMPCMP results and query it in case the regular bitmap is full (= all good). Signed-off-by: Masaharu Hayakawa Signed-off-by: Takeshi Saito Signed-off-by: Wolfram Sang Reviewed-by: Yoshihiro Shimoda Tested-by: Yoshihiro Shimoda --- drivers/mmc/host/renesas_sdhi.h | 2 ++ drivers/mmc/host/renesas_sdhi_core.c | 26 +++++++++++++++++++++++--- 2 files changed, 25 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/host/renesas_sdhi.h b/drivers/mmc/host/renesas_sdhi.h index 2a4c83a5f32e..12d8016672b0 100644 --- a/drivers/mmc/host/renesas_sdhi.h +++ b/drivers/mmc/host/renesas_sdhi.h @@ -61,6 +61,8 @@ struct renesas_sdhi { /* Tuning values: 1 for success, 0 for failure */ DECLARE_BITMAP(taps, BITS_PER_LONG); + /* Sampling data comparison: 1 for match, 0 for mismatch */ + DECLARE_BITMAP(smpcmp, BITS_PER_LONG); unsigned int tap_num; unsigned long tap_set; }; diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index 0dbee47eafa1..796b5eb50415 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -428,7 +428,8 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) { struct renesas_sdhi *priv = host_to_priv(host); unsigned int tap_start = 0, tap_end = 0, tap_cnt = 0, rs, re, i; - unsigned int taps_size = priv->tap_num * 2; + unsigned int taps_size = priv->tap_num * 2, min_tap_row; + unsigned long *bitmap; priv->doing_tune = false; sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); @@ -443,6 +444,21 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) if (!test_bit(i, priv->taps)) clear_bit(i + offset, priv->taps); + + if (!test_bit(i, priv->smpcmp)) + clear_bit(i + offset, priv->smpcmp); + } + + /* + * If all TAP are OK, the sampling clock position is selected by + * identifying the change point of data. + */ + if (bitmap_full(priv->taps, taps_size)) { + bitmap = priv->smpcmp; + min_tap_row = 1; + } else { + bitmap = priv->taps; + min_tap_row = SH_MOBILE_SDHI_MIN_TAP_ROW; } /* @@ -450,7 +466,7 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) * is at least SH_MOBILE_SDHI_MIN_TAP_ROW probes long then use the * center index as the tap, otherwise bail out. */ - bitmap_for_each_set_region(priv->taps, rs, re, 0, taps_size) { + bitmap_for_each_set_region(bitmap, rs, re, 0, taps_size) { if (re - rs > tap_cnt) { tap_end = re; tap_start = rs; @@ -458,7 +474,7 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) } } - if (tap_cnt >= SH_MOBILE_SDHI_MIN_TAP_ROW) + if (tap_cnt >= min_tap_row) priv->tap_set = (tap_start + tap_end) / 2 % priv->tap_num; else return -EIO; @@ -491,6 +507,7 @@ static int renesas_sdhi_execute_tuning(struct tmio_mmc_host *host, u32 opcode) priv->doing_tune = true; bitmap_zero(priv->taps, priv->tap_num * 2); + bitmap_zero(priv->smpcmp, priv->tap_num * 2); /* Issue CMD19 twice for each tap */ for (i = 0; i < 2 * priv->tap_num; i++) { @@ -499,6 +516,9 @@ static int renesas_sdhi_execute_tuning(struct tmio_mmc_host *host, u32 opcode) if (mmc_send_tuning(host->mmc, opcode, NULL) == 0) set_bit(i, priv->taps); + + if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_SMPCMP) == 0) + set_bit(i, priv->smpcmp); } return renesas_sdhi_select_tuning(host);