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@xxxxxxx>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 55 +++++++++++++-----------------
1 file changed, 24 insertions(+), 31 deletions(-)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index cf187f8dbc6c..0489b60b8eb4 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -141,9 +141,6 @@
/* The IP supports HS400 mode */
#define ESDHC_FLAG_HS400 BIT(9)
-/* A clock frequency higher than this rate requires strobe dll control */
-#define ESDHC_STROBE_DLL_CLK_FREQ 100000000
-
struct esdhc_soc_data {
u32 flags;
};
@@ -907,39 +904,35 @@ 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);
-
- /* 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");
- }
+ /* 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");
}
static void esdhc_reset_tuning(struct sdhci_host *host)
--
2.17.1
