From patchwork Mon Feb 10 08:49:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bough Chen X-Patchwork-Id: 11372805 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 5E249109A for ; Mon, 10 Feb 2020 08:55:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4967521739 for ; Mon, 10 Feb 2020 08:55:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727436AbgBJIz2 (ORCPT ); Mon, 10 Feb 2020 03:55:28 -0500 Received: from inva020.nxp.com ([92.121.34.13]:36260 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727079AbgBJIz2 (ORCPT ); Mon, 10 Feb 2020 03:55:28 -0500 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 207CF1BC5BD; Mon, 10 Feb 2020 09:55:26 +0100 (CET) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 6A1B91BC5B8; Mon, 10 Feb 2020 09:55:22 +0100 (CET) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id E2EFE402B0; Mon, 10 Feb 2020 16:55:17 +0800 (SGT) From: haibo.chen@nxp.com To: adrian.hunter@intel.com, ulf.hansson@linaro.org, linux-mmc@vger.kernel.org Cc: linux-imx@nxp.com, haibo.chen@nxp.com, linus.walleij@linaro.org Subject: [PATCH v3 07/14] mmc: sdhci-esdhc-imx: optimize the clock setting Date: Mon, 10 Feb 2020 16:49:50 +0800 Message-Id: <1581324597-31031-2-git-send-email-haibo.chen@nxp.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1581324597-31031-1-git-send-email-haibo.chen@nxp.com> References: <1581324597-31031-1-git-send-email-haibo.chen@nxp.com> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org From: Haibo Chen When force clock off, check the SDOFF of register PRSSTAT to make sure the clock is gate off. Before force clock on, check the SDSTB of register PRSSTAT to make sure the clock is stable, this will eliminate the clock glitch. Signed-off-by: Haibo Chen Acked-by: Adrian Hunter --- drivers/mmc/host/sdhci-esdhc-imx.c | 24 +++++++++++++++++++++++- drivers/mmc/host/sdhci-esdhc.h | 1 + 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 3359153304a3..6ca01b766604 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -9,6 +9,7 @@ */ #include +#include #include #include #include @@ -312,6 +313,17 @@ static inline void esdhc_clrset_le(struct sdhci_host *host, u32 mask, u32 val, i writel(((readl(base) & ~(mask << shift)) | (val << shift)), base); } +static inline void esdhc_wait_for_card_clock_gate_off(struct sdhci_host *host) +{ + u32 present_state; + int ret; + + ret = readl_poll_timeout(host->ioaddr + ESDHC_PRSSTAT, present_state, + (present_state & ESDHC_CLOCK_GATE_OFF), 2, 100); + if (ret == -ETIMEDOUT) + dev_warn(mmc_dev(host->mmc), "%s: card clock still not gate off in 100us!.\n", __func__); +} + static u32 esdhc_readl_le(struct sdhci_host *host, int reg) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); @@ -525,6 +537,8 @@ static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg) else new_val &= ~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON; writel(new_val, host->ioaddr + ESDHC_VENDOR_SPEC); + if (!(new_val & ESDHC_VENDOR_SPEC_FRC_SDCLK_ON)) + esdhc_wait_for_card_clock_gate_off(host); return; case SDHCI_HOST_CONTROL2: new_val = readl(host->ioaddr + ESDHC_VENDOR_SPEC); @@ -753,12 +767,14 @@ static inline void esdhc_pltfm_set_clock(struct sdhci_host *host, int ddr_pre_div = imx_data->is_ddr ? 2 : 1; int pre_div = 1; int div = 1; + int ret; u32 temp, val; if (esdhc_is_usdhc(imx_data)) { val = readl(host->ioaddr + ESDHC_VENDOR_SPEC); writel(val & ~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON, host->ioaddr + ESDHC_VENDOR_SPEC); + esdhc_wait_for_card_clock_gate_off(host); } if (clock == 0) { @@ -813,13 +829,18 @@ static inline void esdhc_pltfm_set_clock(struct sdhci_host *host, | (pre_div << ESDHC_PREDIV_SHIFT)); sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL); + /* need to wait the bit 3 of the PRSSTAT to be set, make sure card clock is stable */ + ret = readl_poll_timeout(host->ioaddr + ESDHC_PRSSTAT, temp, + (temp & ESDHC_CLOCK_STABLE), 2, 100); + if (ret == -ETIMEDOUT) + dev_warn(mmc_dev(host->mmc), "card clock still not stable in 100us!.\n"); + if (esdhc_is_usdhc(imx_data)) { val = readl(host->ioaddr + ESDHC_VENDOR_SPEC); writel(val | ESDHC_VENDOR_SPEC_FRC_SDCLK_ON, host->ioaddr + ESDHC_VENDOR_SPEC); } - mdelay(1); } static unsigned int esdhc_pltfm_get_ro(struct sdhci_host *host) @@ -1003,6 +1024,7 @@ static void esdhc_set_strobe_dll(struct sdhci_host *host) writel(readl(host->ioaddr + ESDHC_VENDOR_SPEC) & ~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON, host->ioaddr + ESDHC_VENDOR_SPEC); + esdhc_wait_for_card_clock_gate_off(host); /* force a reset on strobe dll */ writel(ESDHC_STROBE_DLL_CTRL_RESET, diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h index 9289bb4d633e..947212f16bc6 100644 --- a/drivers/mmc/host/sdhci-esdhc.h +++ b/drivers/mmc/host/sdhci-esdhc.h @@ -31,6 +31,7 @@ /* Present State Register */ #define ESDHC_PRSSTAT 0x24 +#define ESDHC_CLOCK_GATE_OFF 0x00000080 #define ESDHC_CLOCK_STABLE 0x00000008 /* Protocol Control Register */