diff options
| author | Dong Aisheng <b29396@freescale.com> | 2013-10-18 15:48:47 +0400 |
|---|---|---|
| committer | Chris Ball <chris@printf.net> | 2013-10-21 23:58:13 +0400 |
| commit | 602519b2bd63adfdf9e24b2f94aaddcfeb464e9e (patch) | |
| tree | 818c25ef9f7c6db0d89f09753896666f013bf4e6 /include/linux | |
| parent | de5bdbffd89dea0e3de76f99b0b036422bb93686 (diff) | |
| download | linux-602519b2bd63adfdf9e24b2f94aaddcfeb464e9e.tar.xz | |
mmc: sdhci-esdhc-imx: add delay line setting support
The DLL(Delay Line) is newly added to assist in sampling read data.
The DLL provides the ability to programmatically select a quantized
delay (in fractions of the clock period) regardless of on-chip variations
such as process, voltage and temperature (PVT).
This patch adds a user interface to set slave delay line via device tree.
It's usually used in high speed mode like mmc DDR mode when the signal
quality is not good caused by board design, e.g. the signal path is too
long. User can manually set delay line to find a suitable data sampling
window for card to work properly.
Signed-off-by: Dong Aisheng <b29396@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/platform_data/mmc-esdhc-imx.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h index a0f5a8f9b3bc..75f70f6ac137 100644 --- a/include/linux/platform_data/mmc-esdhc-imx.h +++ b/include/linux/platform_data/mmc-esdhc-imx.h @@ -45,5 +45,6 @@ struct esdhc_platform_data { int max_bus_width; unsigned int f_max; bool support_vsel; + unsigned int delay_line; }; #endif /* __ASM_ARCH_IMX_ESDHC_H */ |