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authorHaibo Chen <haibo.chen@nxp.com>2020-02-19 09:25:49 +0100
committerUlf Hansson <ulf.hansson@linaro.org>2020-03-24 14:35:41 +0100
commit5bd2acdcdde22231057b12ee8978dd87c29ff322 (patch)
treed82d5f741b3df09d2cffb2840f1240323308f3ed /drivers/mmc
parentdoc: dt: fsl-imx-esdhc: add strobe-dll-delay-target binding (diff)
downloadlinux-5bd2acdcdde22231057b12ee8978dd87c29ff322.tar.xz
linux-5bd2acdcdde22231057b12ee8978dd87c29ff322.zip
mmc: sdhci-esdhc-imx: add strobe-dll-delay-target support
strobe-dll-delay-target is the delay cell add on the strobe line. Strobe line the the uSDHC loopback read clock which is use in HS400 mode. Different strobe-dll-delay-target may need to set for different board/SoC. If this delay cell is not set to an appropriate value, we may see some read operation meet CRC error after HS400 mode select which already pass the tuning. This patch add the strobe-dll-delay-target setting in driver, so that user can easily config this delay cell in dts file. Signed-off-by: Haibo Chen <haibo.chen@nxp.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Link: https://lore.kernel.org/r/1582100757-20683-1-git-send-email-haibo.chen@nxp.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/sdhci-esdhc-imx.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 6bcdc5743d94..3359153304a3 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -73,6 +73,7 @@
#define ESDHC_STROBE_DLL_CTRL 0x70
#define ESDHC_STROBE_DLL_CTRL_ENABLE (1 << 0)
#define ESDHC_STROBE_DLL_CTRL_RESET (1 << 1)
+#define ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_DEFAULT 0x7
#define ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT 3
#define ESDHC_STROBE_DLL_CTRL_SLV_UPDATE_INT_DEFAULT (4 << 20)
@@ -993,6 +994,9 @@ static int esdhc_change_pinstate(struct sdhci_host *host,
*/
static void esdhc_set_strobe_dll(struct sdhci_host *host)
{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
+ u32 strobe_delay;
u32 v;
/* disable clock before enabling strobe dll */
@@ -1010,9 +1014,13 @@ static void esdhc_set_strobe_dll(struct sdhci_host *host)
* enable strobe dll ctrl and adjust the delay target
* for the uSDHC loopback read clock
*/
+ if (imx_data->boarddata.strobe_dll_delay_target)
+ strobe_delay = imx_data->boarddata.strobe_dll_delay_target;
+ else
+ strobe_delay = ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_DEFAULT;
v = ESDHC_STROBE_DLL_CTRL_ENABLE |
ESDHC_STROBE_DLL_CTRL_SLV_UPDATE_INT_DEFAULT |
- (7 << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT);
+ (strobe_delay << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT);
writel(v, host->ioaddr + ESDHC_STROBE_DLL_CTRL);
/* wait 5us to make sure strobe dll status register stable */
udelay(5);
@@ -1338,6 +1346,8 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
of_property_read_u32(np, "fsl,tuning-start-tap",
&boarddata->tuning_start_tap);
+ of_property_read_u32(np, "fsl,strobe-dll-delay-target",
+ &boarddata->strobe_dll_delay_target);
if (of_find_property(np, "no-1-8-v", NULL))
host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;