From patchwork Wed Apr 8 09:46:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 11479709 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 45A441893 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 301822074F for ; Wed, 8 Apr 2020 09:46:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727918AbgDHJqw (ORCPT ); Wed, 8 Apr 2020 05:46:52 -0400 Received: from sauhun.de ([88.99.104.3]:39640 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726726AbgDHJqw (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 6382B2C1FD6; Wed, 8 Apr 2020 11:46:50 +0200 (CEST) From: Wolfram Sang To: linux-mmc@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , Wolfram Sang Subject: [PATCH v2 1/3] mmc: renesas_sdhi: refactor calculation of best TAP Date: Wed, 8 Apr 2020 11:46:36 +0200 Message-Id: <20200408094638.10375-2-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 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 Reviewed-by: Yoshihiro Shimoda --- Change since RFT/v1: * fix off by one error spotted by Shimoda-san 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..f5d174d86117 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 - rs > tap_cnt) { + tap_end = re; + 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 From patchwork Wed Apr 8 09:46:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 11479711 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 70D8E1892 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 51B582083E for ; Wed, 8 Apr 2020 09:46:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726726AbgDHJqw (ORCPT ); Wed, 8 Apr 2020 05:46:52 -0400 Received: from sauhun.de ([88.99.104.3]:39648 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727079AbgDHJqw (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 CE18B2C1FDC; Wed, 8 Apr 2020 11:46:50 +0200 (CEST) From: Wolfram Sang To: linux-mmc@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , Wolfram Sang Subject: [PATCH v2 2/3] mmc: renesas_sdhi: clarify handling of selecting TAPs Date: Wed, 8 Apr 2020 11:46:37 +0200 Message-Id: <20200408094638.10375-3-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 The comment and the define about how TAPs are selected were confusing to me because the good TAP was only valid if it was bigger than a *_MAX_* value. Rename the define and adapt the comment to what really happens. Signed-off-by: Wolfram Sang Reviewed-by: Yoshihiro Shimoda --- drivers/mmc/host/renesas_sdhi_core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c index f5d174d86117..0dbee47eafa1 100644 --- a/drivers/mmc/host/renesas_sdhi_core.c +++ b/drivers/mmc/host/renesas_sdhi_core.c @@ -422,7 +422,7 @@ static int renesas_sdhi_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_io return 0; } -#define SH_MOBILE_SDHI_MAX_TAP 3 +#define SH_MOBILE_SDHI_MIN_TAP_ROW 3 static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) { @@ -446,9 +446,9 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) } /* - * Find the longest consecutive run of successful probes. If that - * is more than SH_MOBILE_SDHI_MAX_TAP probes long then use the - * center index as the tap. + * Find the longest consecutive run of successful probes. If that + * 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) { if (re - rs > tap_cnt) { @@ -458,7 +458,7 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host) } } - if (tap_cnt >= SH_MOBILE_SDHI_MAX_TAP) + if (tap_cnt >= SH_MOBILE_SDHI_MIN_TAP_ROW) priv->tap_set = (tap_start + tap_end) / 2 % priv->tap_num; else return -EIO; 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);