diff options
| author | Haibo Chen <haibo.chen@nxp.com> | 2025-04-09 15:55:47 +0800 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2025-05-14 16:59:17 +0200 |
| commit | be953af79cc67a3a073fd75cf2bd542353d2ad35 (patch) | |
| tree | 31a45f6f7bd5bf2ab25fb4917d7a42fa6f8c6733 | |
| parent | d0aac7d811775a2e98a02c7f172e0a9e97d9e004 (diff) | |
mmc: sdhci-esdhc-imx: widen auto-tuning window for standard tuning
Expand the auto-tuning window width from 2 to 3 for standard tuning to
account for sampling point shifts caused by temperature change. This change
is based on hardware recommendation, providing 50% more margin for the
auto-tuning logic to locate valid sampling points.
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Luke Wang <ziniu.wang_1@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20250409075550.3413032-4-ziniu.wang_1@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
| -rw-r--r-- | drivers/mmc/host/sdhci-esdhc-imx.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 53c7b858b43c..5c8a00864c1d 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -108,6 +108,7 @@ #define ESDHC_TUNING_CTRL 0xcc #define ESDHC_STD_TUNING_EN (1 << 24) +#define ESDHC_TUNING_WINDOW_MASK GENMASK(22, 20) /* NOTE: the minimum valid tuning start tap for mx6sl is 1 */ #define ESDHC_TUNING_START_TAP_DEFAULT 0x1 #define ESDHC_TUNING_START_TAP_MASK 0x7f @@ -209,6 +210,8 @@ /* The IP does not have GPIO CD wake capabilities */ #define ESDHC_FLAG_SKIP_CD_WAKE BIT(18) +#define ESDHC_AUTO_TUNING_WINDOW 3 + enum wp_types { ESDHC_WP_NONE, /* no WP, neither controller nor gpio */ ESDHC_WP_CONTROLLER, /* mmc controller internal WP */ @@ -1553,6 +1556,16 @@ static void sdhci_esdhc_imx_hwinit(struct sdhci_host *host) << ESDHC_TUNING_STEP_SHIFT; } + /* + * Config the tuning window to the hardware suggested value 3. + * This tuning window is used for auto tuning logic. The default + * tuning window is 2, here change to 3 make the window a bit + * wider, give auto tuning enough space to handle the sample + * point shift cause by temperature change. + */ + tmp &= ~ESDHC_TUNING_WINDOW_MASK; + tmp |= FIELD_PREP(ESDHC_TUNING_WINDOW_MASK, ESDHC_AUTO_TUNING_WINDOW); + /* Disable the CMD CRC check for tuning, if not, need to * add some delay after every tuning command, because * hardware standard tuning logic will directly go to next |