eMMC在封装中集成了一个掌握器，并供应标准接口管理闪存。
从开拓者角度看，只要遵照eMMC协议，既可以对eMMC芯片进行读写操作。
下面先容RK3568 eMMC掌握器驱动和调试方法。
一、eMMC驱动
1、eMMC掌握器
RK3568 eMMC主机掌握器框图如下：
RK3568 eMMC掌握器框图
RK3568 eMMC主机掌握器特性如下：
1）、支持eMMC 5.1协议
2）、支持自动tuning
3）、支持4/8-bit接口
4）、支持 legacy、High Speed SDR、High Speed DDR、HS200/HS400速率模式
5）、AHB从接口：支持32bit数据和地址宽度
6）、AXI主接口：支持32bit地址宽度和64bit数据宽度
7）、时钟调度：支持transmit clock、sample clok和data strobe相位自动调度
2、eMMC事理图
预调驱动，先看事理图。
RK3568和eMMC之间的连接办法见下图：
RK3568 eMMC连接事理图
注：
1）eMMC D0~D8/CMD电压需同等，为3.3V或1.8V
2）Data Strobe时钟旗子暗记由eMMC发给RK3568，频率与CLK 旗子暗记相同。
用于RK3568侧数据吸收的同步。
Data Strobe旗子暗记只能在HS400模式下配置启用，启用后可以提高数据传输的稳定性，省去总线 tuning过程。
3、eMMC配置
RK3568 eMMC配置文件：
1）arch/arm64/boot/dts/rockchip/rk3568.dtsi
sdhci: sdhci@fe310000 { compatible = "rockchip,dwcmshc-sdhci", "snps,dwcmshc-sdhci"; reg = <0x0 0xfe310000 0x0 0x10000>; interrupts = <GIC_SPI 19 IRQ_TYPE_LEVEL_HIGH>; assigned-clocks = <&cru BCLK_EMMC>, <&cru TCLK_EMMC>, <&cru CCLK_EMMC>; assigned-clock-rates = <200000000>, <24000000>, <200000000>; clocks = <&cru CCLK_EMMC>, <&cru HCLK_EMMC>, <&cru ACLK_EMMC>, <&cru BCLK_EMMC>, <&cru TCLK_EMMC>; clock-names = "core", "bus", "axi", "block", "timer"; status = "disabled"; };
2）arch/arm64/boot/dts/rockchip/rk3568-firefly-core.dtsi
&sdhci { bus-width = <8>; supports-emmc; non-removable; max-frequency = <200000000>; status = "okay"; };
个中：
max-frequency：eMMC在该模式下支持的最大运行频率，单位HZ。
注：根据不同的模式进行调度该值，把稳和数据传输速率（Max Data Transfer rate，MB/s）差异。
supports-emmc：表示为emmc功能，必须添加。
否则无法初始化eMMC卡。
bus-width：eMMC利用8线模式。
non-removable：表示该卡槽为不可移动设备，必须添加。
4、eMMC驱动
RK3568 eMMC掌握器利用Synopsys IP。
RK3568驱动文件：drivers/mmc/host/sdhci-of-dwcmshc.c，紧张关注：
static const struct sdhci_ops sdhci_dwcmshc_ops = { .set_clock = sdhci_set_clock, .set_bus_width = sdhci_set_bus_width, .set_uhs_signaling = dwcmshc_set_uhs_signaling, .get_max_clock = sdhci_pltfm_clk_get_max_clock, .reset = sdhci_reset, .adma_write_desc = dwcmshc_adma_write_desc,};static const struct sdhci_ops sdhci_dwcmshc_rk_ops = { .set_clock = dwcmshc_rk_set_clock, .set_bus_width = sdhci_set_bus_width, .set_uhs_signaling = dwcmshc_set_uhs_signaling, .get_max_clock = sdhci_pltfm_clk_get_max_clock, .reset = sdhci_reset, .adma_write_desc = dwcmshc_adma_write_desc,};
二、eMMC调试
1、U-Boot阶段
1.1、查看U-Boot支持的mmc命令
=> mmcmmc - MMC sub systemUsage:mmc info - display info of the current MMC devicemmc read addr blk# cntmmc write addr blk# cntmmc erase blk# cntmmc rescanmmc part - lists available partition on current mmc devicemmc dev [dev] [part] - show or set current mmc device [partition]mmc list - lists available devices...
1.2、显示mmc设备信息
=> mmc infoDevice: sdhci@fe310000Manufacturer ID: 9bOEM: 100Name: Y2P03Timing Interface: HS200 ## EMMC支持的速率模式 Tran Speed: 200000000 ## EMMC速率Rd Block Len: 512 ## block大小512字节MMC version 5.1High Capacity: YesCapacity: 29.1 GiB ## EMMC容量Bus Width: 8-bit ## EMMC总线宽度8bitErase Group Size: 512 KiBHC WP Group Size: 8 MiBUser Capacity: 29.1 GiBBoot Capacity: 4 MiB ENHRPMB Capacity: 16 MiB ENH
1.3、查看mmc设备列表
=> mmc listdwmmc@fe2b0000: 1 ## SDCarddwmmc@fe2c0000: 2 ## SDIOsdhci@fe310000: 0 (eMMC) ## eMMC设备，当前设备
1.4、查看mmc设备分区
当前是eMMC设备，查看的eMMC分区如下：
=> mmc partPartition Map for MMC device 0 -- Partition Type: EFIPart Start LBA End LBA Name Attributes Type GUID Partition GUID 1 0x00004000 0x00005fff "uboot" attrs: 0x0000000000000000 type: 3e240000-0000-4719-8000-1de100003030 guid: cb6b0000-0000-4224-8000-356000002c8d ... 3 0x00008000 0x00027fff "boot" attrs: 0x0000000000000000 type: 32410000-0000-487f-8000-685e0000531d guid: a2570000-0000-4e68-8000-720100007df8 ... 7 0x00098000 0x00497fff "rootfs" attrs: 0x0000000000000000 type: be090000-0000-487c-8000-551300005560 guid: 614e0000-0000-4b53-8000-1d28000054a9 8 0x00498000 0x03a3dfde "userdata" attrs: 0x0000000000000000 type: 323c0000-0000-4345-8000-065600004955 guid: 7d060000-0000-4411-8000-53ba000044af
1.5、eMMC读/写和擦除命令
mmc read addr blk# cntmmc write addr blk# cntmmc erase blk# cnt
注：
addr：内存地址，内存中保存的内容可以通过md命令查看
blk#：eMMC sector地址，sector大小一样平常为512，eMMC的实际地址为512 blk#
cnt：eMMC sector个数
注：合营eMMC读/写和擦除命令，可以实现映像更新等调试功能。
2、内核阶段
在加载Linux内核时，eMMC驱动加载信息如下：
[ 1.187234] mmc0: new HS200 MMC card at address 0001[ 1.188078] mmcblk0: mmc0:0001 Y2P032 29.1 GiB[ 1.188559] mmcblk0boot0: mmc0:0001 Y2P032 partition 1 4.00 MiB[ 1.189039] mmcblk0boot1: mmc0:0001 Y2P032 partition 2 4.00 MiB[ 1.189273] mmcblk0rpmb: mmc0:0001 Y2P032 partition 3 16.0 MiB, chardev (240:0)[ 1.192329] mmcblk0: p1 p2 p3 p4 p5 p6 p7 p8
2.1、查看eMMC属性
[root@xiaotianbsp:/sys/kernel/debug/mmc0]# cat iosclock: 198000000 Hz ## eMMC时钟频率vdd: 18 (3.0 ~ 3.1 V)bus mode: 2 (push-pull)chip select: 0 (don't care)power mode: 2 (on)bus width: 3 (8 bits) ## eMMC数据位宽timing spec: 9 (mmc HS200) ## eMMC速率模式signal voltage: 1 (1.80 V) ## eMMC引脚电平driver type: 0 (driver type B)
2.2、查看eMMC分区名
[root@xiaotianbsp:/dev/block/by-name]# ls -ltotal 0lrwxrwxrwx 1 root root 15 Jan 1 19:32 backup -> ../../mmcblk0p5lrwxrwxrwx 1 root root 15 Jan 1 19:32 boot -> ../../mmcblk0p3lrwxrwxrwx 1 root root 15 Jan 1 19:32 misc -> ../../mmcblk0p2lrwxrwxrwx 1 root root 15 Jan 1 19:32 oem -> ../../mmcblk0p6lrwxrwxrwx 1 root root 15 Jan 1 19:32 recovery -> ../../mmcblk0p4lrwxrwxrwx 1 root root 15 Jan 1 19:32 rootfs -> ../../mmcblk0p7lrwxrwxrwx 1 root root 15 Jan 1 19:32 uboot -> ../../mmcblk0p1lrwxrwxrwx 1 root root 15 Jan 1 19:32 userdata -> ../../mmcblk0p8
2.3、查看eMMC分区
[root@xiaotianbsp:/]# cat /proc/partitionsmajor minor #blocks name 1 0 4096 ram0 179 0 30535680 mmcblk0 179 1 4096 mmcblk0p1 179 2 4096 mmcblk0p2 179 3 65536 mmcblk0p3 179 4 65536 mmcblk0p4 179 5 32768 mmcblk0p5 179 6 131072 mmcblk0p6 179 7 2097152 mmcblk0p7 179 8 28127215 mmcblk0p8 179 96 31166976 mmcblk1 179 97 31166968 mmcblk1p1
2.4、查看eMMC已挂载分区
[root@xiaotianbsp:/]# mount/dev/mmcblk0p7 on / type ext4 (rw,relatime).../dev/mmcblk0p6 on /oem type ext2 (rw,relatime)/dev/mmcblk0p8 on /userdata type ext4 (rw,relatime)...
2.5、查看挂载的eMMC分区大小
[root@xiaotianbsp:/]# df -hFilesystem Size Used Avail Use% Mounted on.../dev/mmcblk0p6 126M 13M 107M 11% /oem/dev/mmcblk0p8 27G 45M 27G 1% /userdata
2.6、按不同办法查看eMMC分区
# 可以按照id/label等办法查看EMMC各分区[root@xiaotianbsp:/dev/disk]# lsby-id by-label by-partlabel by-partuuid by-path by-uuid[root@xiaotianbsp:/dev/disk/by-id]# lsmmc-SD32G_0x54c496d5 mmc-Y2P032_0x745a16bb-part4mmc-SD32G_0x54c496d5-part1 mmc-Y2P032_0x745a16bb-part5mmc-Y2P032_0x745a16bb mmc-Y2P032_0x745a16bb-part6mmc-Y2P032_0x745a16bb-part1 mmc-Y2P032_0x745a16bb-part7mmc-Y2P032_0x745a16bb-part2 mmc-Y2P032_0x745a16bb-part8mmc-Y2P032_0x745a16bb-part3[root@xiaotianbsp:/dev/disk/by-path]# lsplatform-fe2b0000.dwmmc platform-fe310000.sdhci-part3platform-fe2b0000.dwmmc-part1 platform-fe310000.sdhci-part4platform-fe310000.sdhci platform-fe310000.sdhci-part5platform-fe310000.sdhci-boot0 platform-fe310000.sdhci-part6platform-fe310000.sdhci-boot1 platform-fe310000.sdhci-part7platform-fe310000.sdhci-part1 platform-fe310000.sdhci-part8platform-fe310000.sdhci-part2
2.7、查看eMMC时钟关系
1）逐级查找父时钟
# 1.sdmmc0_drv的父时钟是clk_sdmmc0[root@xiaotianbsp:/sys/kernel/debug/clk/sdmmc0_drv]# cat clk_phase180[root@xiaotianbsp:/sys/kernel/debug/clk/sdmmc0_drv]# cat clk_rate148500000[root@xiaotianbsp:/sys/kernel/debug/clk/sdmmc0_drv]# cat clk_parentclk_sdmmc0
# 2.sdmmc0_sample的父时钟是clk_sdmmc0[root@xiaotianbsp:/sys/kernel/debug/clk/sdmmc0_sample]# cat clk_phase264[root@xiaotianbsp:/sys/kernel/debug/clk/sdmmc0_sample]# cat clk_rate148500000[root@xiaotianbsp:/sys/kernel/debug/clk/sdmmc0_sample]# cat clk_parentclk_sdmmc0
# 3.clk_sdmmc0的父时钟是gpll_300m[root@xiaotianbsp:/sys/kernel/debug/clk/clk_sdmmc0]# cat clk_rate297000000[root@xiaotianbsp:/sys/kernel/debug/clk/clk_sdmmc0]# cat clk_parentgpll_300m
# 4.gpll_300m的父时钟是gpll[root@xiaotianbsp:/sys/kernel/debug/clk/gpll_300m]# cat clk_rate297000000[root@xiaotianbsp:/sys/kernel/debug/clk/gpll_300m]# cat clk_parentgpll
# 5.gpll的父时钟是pll_gpll[root@xiaotianbsp:/sys/kernel/debug/clk/gpll]# cat clk_rate1188000000[root@xiaotianbsp:/sys/kernel/debug/clk/gpll]# cat clk_parentpll_gpll
# 5.pll_gpll的父时钟是xin24m[root@xiaotianbsp:/sys/kernel/debug/clk/pll_gpll]# cat clk_parentxin24m[root@xiaotianbsp:/sys/kernel/debug/clk/pll_gpll]# cat clk_rate1188000000
2）直接查找时钟树
[root@xiaotianbsp:/sys/kernel/debug/clk]# cat clk_summary enable prepare protect duty clock count count count rate accuracy phase cycle---------------------------------------------------------------------------------------------... xin24m 22 24 0 24000000 0 0 50000... pll_gpll 1 1 0 1188000000 0 0 50000 gpll 6 14 0 1188000000 0 0 50000 ... gpll_300m 5 9 0 297000000 0 0 50000 clk_sdmmc0 1 1 0 297000000 0 0 50000 sdmmc0_sample 0 0 0 148500000 0 263 50000 sdmmc0_drv 0 0 0 148500000 0 180 50000...
2.8、eMMC读写测试
## eMMC读echo 3 > /proc/sys/vm/drop_cachestime dd if=/dev/mmcblk0p8 of=/dev/null bs=1M count=300## eMMC写，test是eMMC某个分区内的文件夹time dd if=/dev/zero of=test bs=1M count=300 conv=fsync
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