From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock. Date: Thu, 23 Aug 2012 20:31:49 +0900 Message-ID: <503614A5.5090906@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout2.samsung.com ([203.254.224.25]:22746 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755128Ab2HWLcI (ORCPT ); Thu, 23 Aug 2012 07:32:08 -0400 Received: from epcpsbgm1.samsung.com (mailout2.samsung.com [203.254.224.25]) by mailout2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0M9700L0VHD7CG20@mailout2.samsung.com> for linux-mmc@vger.kernel.org; Thu, 23 Aug 2012 20:32:05 +0900 (KST) Received: from [10.90.51.55] by mmp2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0M9700JGPHDGWSB0@mmp2.samsung.com> for linux-mmc@vger.kernel.org; Thu, 23 Aug 2012 20:32:05 +0900 (KST) Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc Cc: Chris Ball , Kyungmin Park , Will Newton , James Hogan To avoid glitches in the card clock output, need to check whether card is busy or not. Signed-off-by: Jaehoon Chung Signed-off-by: Kyungmin Park --- drivers/mmc/host/dw_mmc.c | 30 ++++++++++++++++++++++++------ drivers/mmc/host/dw_mmc.h | 1 + 2 files changed, 25 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 36f98c0..8bef3c2 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg) cmd, arg, cmd_status); } +static void dw_mci_inform_ciu(struct dw_mci_slot *slot) +{ + struct dw_mci *host = slot->host; + unsigned long timeout = jiffies + msecs_to_jiffies(500); + u32 ctrl, status; + + do { + status = mci_readl(host, STATUS); + if (!(status & SDMMC_DATA_BUSY)) + break; + ctrl = mci_readl(host, CTRL); + ctrl |= SDMMC_CTRL_RESET; + mci_writel(host, CTRL, ctrl); + } while (time_before(jiffies, timeout)); + + if (status & SDMMC_DATA_BUSY) + dev_err(&slot->mmc->class_dev,"Card is busy..!\n"); + + mci_send_cmd(slot, SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); +} + static void dw_mci_setup_bus(struct dw_mci_slot *slot) { struct dw_mci *host = slot->host; @@ -650,15 +671,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot) mci_writel(host, CLKSRC, 0); /* inform CIU */ - mci_send_cmd(slot, - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); + dw_mci_inform_ciu(slot); /* set clock to desired speed */ mci_writel(host, CLKDIV, div); /* inform CIU */ - mci_send_cmd(slot, - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); + dw_mci_inform_ciu(slot); /* enable clock; only low power if no SDIO */ clk_en_a = SDMMC_CLKEN_ENABLE << slot->id; @@ -667,8 +686,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot) mci_writel(host, CLKENA, clk_en_a); /* inform CIU */ - mci_send_cmd(slot, - SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT, 0); + dw_mci_inform_ciu(slot); host->current_speed = slot->clock; } diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h index 15c27e1..b6a1a78 100644 --- a/drivers/mmc/host/dw_mmc.h +++ b/drivers/mmc/host/dw_mmc.h @@ -127,6 +127,7 @@ #define SDMMC_CMD_INDX(n) ((n) & 0x1F) /* Status register defines */ #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF) +#define SDMMC_DATA_BUSY BIT(9) /* Internal DMAC interrupt defines */ #define SDMMC_IDMAC_INT_AI BIT(9) #define SDMMC_IDMAC_INT_NI BIT(8) -- 1.7.4.1