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mmc: sdhci-esdhc-imx: remove the 100MHz limitation for Strobe DLL

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For some eMMC, after switch to HS400ES mode, it need to config the strobe
dll target dealy even if the clock is 50MHZ or 25MHz, otherwise will meet
CMD index/crc error when send CMD13 to check the switch status.

[    2.473915] IRQ status 0x000a8001
[    2.473934] mmc2: mmc_select_hs400es failed, error -84
[    2.473938] mmc2: error -84 whilst initialising MMC card

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
BOUGH CHEN 2019-01-07 10:11:29 +00:00 committed by Ulf Hansson
parent bb60023c63
commit 2b0efe8204
1 changed files with 23 additions and 29 deletions
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52
drivers/mmc/host/sdhci-esdhc-imx.c
View file

@ -144,8 +144,6 @@
* exceed 150MHz, for DDR mode, SD card clock can't exceed 45MHz.
*/
#define ESDHC_FLAG_ERR010450 BIT(10)
/* A clock frequency higher than this rate requires strobe dll control */
#define ESDHC_STROBE_DLL_CLK_FREQ 100000000
struct esdhc_soc_data {
u32 flags;
@ -939,39 +937,35 @@ static int esdhc_change_pinstate(struct sdhci_host *host,
* edge of data_strobe line. Due to the time delay between CLK line and
* data_strobe line, if the delay time is larger than one clock cycle,
* then CLK and data_strobe line will be misaligned, read error shows up.
* So when the CLK is higher than 100MHz, each clock cycle is short enough,
* host should configure the delay target.
*/
static void esdhc_set_strobe_dll(struct sdhci_host *host)
{
u32 v;
if (host->mmc->actual_clock > ESDHC_STROBE_DLL_CLK_FREQ) {
/* disable clock before enabling strobe dll */
writel(readl(host->ioaddr + ESDHC_VENDOR_SPEC) &
~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON,
host->ioaddr + ESDHC_VENDOR_SPEC);
/* disable clock before enabling strobe dll */
writel(readl(host->ioaddr + ESDHC_VENDOR_SPEC) &
~ESDHC_VENDOR_SPEC_FRC_SDCLK_ON,
host->ioaddr + ESDHC_VENDOR_SPEC);
/* force a reset on strobe dll */
writel(ESDHC_STROBE_DLL_CTRL_RESET,
host->ioaddr + ESDHC_STROBE_DLL_CTRL);
/*
* enable strobe dll ctrl and adjust the delay target
* for the uSDHC loopback read clock
*/
v = ESDHC_STROBE_DLL_CTRL_ENABLE |
(7 << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT);
writel(v, host->ioaddr + ESDHC_STROBE_DLL_CTRL);
/* wait 1us to make sure strobe dll status register stable */
udelay(1);
v = readl(host->ioaddr + ESDHC_STROBE_DLL_STATUS);
if (!(v & ESDHC_STROBE_DLL_STS_REF_LOCK))
dev_warn(mmc_dev(host->mmc),
"warning! HS400 strobe DLL status REF not lock!\n");
if (!(v & ESDHC_STROBE_DLL_STS_SLV_LOCK))
dev_warn(mmc_dev(host->mmc),
"warning! HS400 strobe DLL status SLV not lock!\n");
}
/* force a reset on strobe dll */
writel(ESDHC_STROBE_DLL_CTRL_RESET,
host->ioaddr + ESDHC_STROBE_DLL_CTRL);
/*
* enable strobe dll ctrl and adjust the delay target
* for the uSDHC loopback read clock
*/
v = ESDHC_STROBE_DLL_CTRL_ENABLE |
(7 << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT);
writel(v, host->ioaddr + ESDHC_STROBE_DLL_CTRL);
/* wait 1us to make sure strobe dll status register stable */
udelay(1);
v = readl(host->ioaddr + ESDHC_STROBE_DLL_STATUS);
if (!(v & ESDHC_STROBE_DLL_STS_REF_LOCK))
dev_warn(mmc_dev(host->mmc),
"warning! HS400 strobe DLL status REF not lock!\n");
if (!(v & ESDHC_STROBE_DLL_STS_SLV_LOCK))
dev_warn(mmc_dev(host->mmc),
"warning! HS400 strobe DLL status SLV not lock!\n");
}
static void esdhc_reset_tuning(struct sdhci_host *host)