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From: Dong Aisheng <b29396@freescale.com>
To: linux-mmc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org, cjb@laptop.org,
	shawn.guo@linaro.org, anton@enomsg.org, s.hauer@pengutronix.de,
	w.sang@pengutronix.de, ulf.hansson@linaro.org,
	neko@bakuhatsu.net, b29396@freescale.com
Subject: [PATCH v2 7/9] mmc: sdhci-esdhc-imx: correct pre_div for imx6q
Date: Fri, 13 Sep 2013 19:11:36 +0800	[thread overview]
Message-ID: <1379070698-7344-8-git-send-email-b29396@freescale.com> (raw)
In-Reply-To: <1379070698-7344-1-git-send-email-b29396@freescale.com>

According to spec, the pre_div for imx6q should be 1, or the biggest clock
rate we can get is a half of host clock rate.
This may cause we can not get the proper clock rate as we want.
e.g. if the desired clock is 200Mhz, however, the host clock is 200Mhz too,
then it causes the actual clock we get is 100Mhz due to pre_div is 2.

Signed-off-by: Dong Aisheng <b29396@freescale.com>
---
 drivers/mmc/host/sdhci-esdhc-imx.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index ed00d6d..fe48ec3 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -510,6 +510,9 @@ static inline void esdhc_pltfm_set_clock(struct sdhci_host *host,
 		goto out;
 	}
 
+	if (is_imx6q_usdhc(imx_data))
+		pre_div = 1;
+
 	temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
 	temp &= ~(ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN
 		| ESDHC_CLOCK_MASK);
-- 
1.7.1



  parent reply	other threads:[~2013-09-13 11:21 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-13 11:11 [PATCH v2 0/9] mmc: sdhci-esdhc-imx: add SD3.0 support Dong Aisheng
2013-09-13 11:11 ` [PATCH v2 1/9] mmc: sdhci: add hooks for platform specific tuning Dong Aisheng
2013-09-13 11:11 ` [PATCH v2 2/9] mmc: sdhci: allow platform access of sdhci_send_command Dong Aisheng
2013-09-13 11:11 ` [PATCH v2 3/9] mmc: sdhci-esdhci: move common esdhc_set_clock to platform driver Dong Aisheng
2013-09-13 11:11 ` [PATCH v2 4/9] sdhci: sdhci-esdhc-imx: support real clock on and off for imx6q Dong Aisheng
2013-09-13 11:11 ` [PATCH v2 5/9] sdhci: sdhci-esdhci-imx: add sd3.0 clock tuning support Dong Aisheng
2013-09-13 11:11 ` [PATCH v2 6/9] sdhci: sdhci-esdhc-imx: change pinctrl state according to uhs mode Dong Aisheng
2013-09-13 11:11 ` Dong Aisheng [this message]
2013-09-13 11:11 ` [PATCH v2 8/9] mmc: sdhci-esdhc-imx: set actual_clock in clock setting Dong Aisheng
2013-09-13 11:11 ` [PATCH v2 9/9] ARM: dts: imx6qdl: add uhs pinctrl state for usdhc3 Dong Aisheng
2013-09-16  8:44   ` Shawn Guo
2013-09-26  2:01 ` [PATCH v2 0/9] mmc: sdhci-esdhc-imx: add SD3.0 support Chris Ball
2013-09-26  9:02   ` Shawn Guo
2013-09-26 11:57     ` Chris Ball

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