mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-26 22:24:09 +08:00
cd587096c0
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>
34 lines
1.1 KiB
Plaintext
34 lines
1.1 KiB
Plaintext
* TI Highspeed MMC host controller for OMAP
|
|
|
|
The Highspeed MMC Host Controller on TI OMAP family
|
|
provides an interface for MMC, SD, and SDIO types of memory cards.
|
|
|
|
This file documents differences between the core properties described
|
|
by mmc.txt and the properties used by the omap_hsmmc driver.
|
|
|
|
Required properties:
|
|
- compatible:
|
|
Should be "ti,omap2-hsmmc", for OMAP2 controllers
|
|
Should be "ti,omap3-hsmmc", for OMAP3 controllers
|
|
Should be "ti,omap4-hsmmc", for OMAP4 controllers
|
|
- ti,hwmods: Must be "mmc<n>", n is controller instance starting 1
|
|
|
|
Optional properties:
|
|
ti,dual-volt: boolean, supports dual voltage cards
|
|
<supply-name>-supply: phandle to the regulator device tree node
|
|
"supply-name" examples are "vmmc", "vmmc_aux" etc
|
|
ti,non-removable: non-removable slot (like eMMC)
|
|
ti,needs-special-reset: Requires a special softreset sequence
|
|
ti,needs-special-hs-handling: HSMMC IP needs special setting for handling High Speed
|
|
|
|
Example:
|
|
mmc1: mmc@0x4809c000 {
|
|
compatible = "ti,omap4-hsmmc";
|
|
reg = <0x4809c000 0x400>;
|
|
ti,hwmods = "mmc1";
|
|
ti,dual-volt;
|
|
bus-width = <4>;
|
|
vmmc-supply = <&vmmc>; /* phandle to regulator node */
|
|
ti,non-removable;
|
|
};
|