HSMMC IP on AM33xx need a special setting to handle High-speed cards.
Other platforms like TI81xx, OMAP4 may need this as-well. This depends
on the HSMMC IP timing closure done for the high speed cards.
From AM335x TRM (SPRUH73F - 18.3.12 Output Signals Generation):
The MMC/SD/SDIO output signals can be driven on either falling edge or
rising edge depending on the SD_HCTL[2] HSPE bit. This feature allows
to reach better timing performance, and thus to increase data transfer
frequency.
There are few pre-requisites for enabling the HSPE bit
- Controller should support High-Speed-Enable Bit and
- Controller should not be using DDR Mode and
- Controller should advertise that it supports High Speed in
capabilities register and
- MMC/SD clock coming out of controller > 25MHz
Signed-off-by: Hebbar, Gururaja <gururaja.hebbar@ti.com>
Signed-off-by: Venkatraman S <svenkatr@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Now that we have common bindings for MMC, rewrite the individual
bindings to inherit from mmc.txt and describe their differences.
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
This patch unifies the current DT MMC bindings documentation and code,
adds generic MMC DT bindings documentation, and updates .dts files for
consistency.
[cjb: typo fixes, addition of max-frequency property]
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Define dt bindings for the ti-omap-hsmmc, and adapt the driver to extract
data (which was earlier passed as platform_data) from device tree.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Hebbar, Gururaja