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

NA

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

 

        NA            

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

 

6      Test Method