am335x system upgrade kernel emmc(十八)

1 Scope of Document

This document describes EMMC hardware design

2 Requiremen

2.1 Function Requirement

support 4G capacity EMMC in linux

2.2 Performance Requirement

3 Hardware Overview

standard 8 bit emmc interface, eight data line ,one line for emmc_cmd, one line for emmc_clk

4 Functional Description

4.1 Functional Block Diagram

4.2 EMMC

4.2.1 Overview

Reference: https://blog.csdn.net/wuyusheng314/article/details/64127687

https://blog.csdn.net/u013686019/article/details/66472291

5 Porting

5.1 4.14.40 Kernel porting

Change the dts file for support EMMC

mmc2_pins: pinmux_mmc2_pins {

pinctrl-single,pins = <

AM33XX_IOPAD(0x880, PIN_INPUT_PULLUP | MUX_MODE2) /* (U9) gpmc_csn1.mmc1_clk */

AM33XX_IOPAD(0x884, PIN_INPUT_PULLUP | MUX_MODE2) /* (V9) gpmc_csn2.mmc1_cmd */

AM33XX_IOPAD(0x800, PIN_INPUT_PULLUP | MUX_MODE1) /* (U7) gpmc_ad0.mmc1_dat0 */

AM33XX_IOPAD(0x804, PIN_INPUT_PULLUP | MUX_MODE1) /* (V7) gpmc_ad1.mmc1_dat1 */

AM33XX_IOPAD(0x808, PIN_INPUT_PULLUP | MUX_MODE1) /* (R8) gpmc_ad2.mmc1_dat2 */

AM33XX_IOPAD(0x80c, PIN_INPUT_PULLUP | MUX_MODE1) /* (T8) gpmc_ad3.mmc1_dat3 */

AM33XX_IOPAD(0x810, PIN_INPUT_PULLUP | MUX_MODE1) /* (U8) gpmc_ad4.mmc1_dat4 */

AM33XX_IOPAD(0x814, PIN_INPUT_PULLUP | MUX_MODE1) /* (V8) gpmc_ad5.mmc1_dat5 */

AM33XX_IOPAD(0x818, PIN_INPUT_PULLUP | MUX_MODE1) /* (R9) gpmc_ad6.mmc1_dat6 */

AM33XX_IOPAD(0x81c, PIN_INPUT_PULLUP | MUX_MODE1) /* (T9) gpmc_ad7.mmc1_dat7 */

};

&mmc2 {

status = "okay";

vmmc-supply = <&vcc3v3>;

bus-width = <8>;

pinctrl-names = "default";

pinctrl-0 = <&mmc2_pins>;

};

Kernel log:

[ 1.814326] mmc1: new high speed MMC card at address 0001

[ 1.830872] mmcblk1: mmc1:0001 SEM04G 3.69 GiB

[ 1.835755] mmcblk1boot0: mmc1:0001 SEM04G partition 1 1.00 MiB

Device interface:

# ls /dev/mmcblk1*

mmcblk1 mmcblk1boot0 mmcblk1boot1 mmcblk1p1 mmcblk1p2