Linux内核增加HDF驱动子系统

前言

HDF驱动子系统是OpenHarmony重要的特色功能之一，其主要的功能是实现驱动程序在多内核多平台的物联网环境，实现一次驱动开发，多端部署。之前移植OHOS3.0使用了传统的linux驱动，比较遗憾，今天尝试将HDF驱动子系统加入编译框架。开始前先了解几个名词。

HCS(HDF Configuration Source)是 HDF 驱动框架的配置描述源码，JSON存储。

HC-GEN(HDF Configuration Generator)是 HCS 配置转换工具，可以将 HDF 配置文件HCS转换为二进制HCB。

HCB(HDF Configuration Binary)二进制文件，驱动可使用 HDF 框架提供的配置解析接口获取配置。

内核打补丁

如何在内核加入HDF驱动，linux内核下主要实现是下面两个目录：

drivers\adapter\khdf\linux 和 drivers\framework

这两个目录是通过链接的方式加入到内核编译的，流程如下：

kernel\linux\build\kernel.mk：75

$(hide) cd $(KERNEL_SRC_TMP_PATH) && patch -p1 < $(HDF_PATCH_FILE) && patch -p1 < $(DEVICE_PATCH_FILE)

可以参考3516的HDF补丁：kernel\linux\patches\linux-5.10\hi3516dv300_patch\hdf.patch

patching file drivers/Kconfig
patching file drivers/Makefile
patching file drivers/hdf/Makefile
patching symbolic link drivers/hdf/framework
patching symbolic link drivers/hdf/khdf
patching symbolic link include/hdf
# 添加到linux内核的补丁
drivers/hdf/framework -> /drivers/framework/ # 驱动子系统驱动框架、配置管理、配置解析、驱动通用框架模型、硬件通用平台能力接口等
drivers/hdf/khdf -> /drivers/adapter/khdf/linux/ # 在linux内核中部署OpenHarmony驱动框架
drivers/hdf/Makefile # 由hdf.patch提供
include/hdf -> /drivers/framework/include/ # 驱动框架对外提供能力的头文件

内核配置

只是打上补丁还不行，还得在内核的编译配置文件中加入HDF选项。最开始的做法就是参考3516的配置选择，但是发现有些配置会导致编译失败。测试发现下面的配置是可以编译成功的。

[*] Enable HDF manager
(2) Set HDF support platform
[*] Enable HDF platform driver
[*] Enable HDF platform mipi dsi driver
[*] Enable HDF platform gpio driver
[*] Enable HDF platform i2c driver
[*] Enable HDF platform watchdog driver
[*] hi35xx pwm driver
[*] Enable HDF platform pwm driver
[*] Enable HDF platform uart driver
[ ] Enable HDF platform sdio driver
[ ] Enable HDF platform emmc driver
[*] Enable HDF platform mmc driver
[*] Enable HDF platform spi driver
[*] Enable HDF platform rtc driver
[*] Enable HDF linux test
[*] Enable HDF Display driver
[ ] Enable HDF Lcdkit driver
[*] Enable HDF Icn9700 driver
[ ] Enable HDF St7789 driver
[*] Enable HDF input driver
[*] Enable HDF tp 5P5 GT911 driver
[*] Enable HDF tp 2P35 FT6236 driver
[ ] Enable HDF wifi
[ ] Enable HDF Bluetooth
[*] Enable HDF sensor driver
[ ] Enable HDF accel sensor driver
[ ] Enable HDF gyro sensor driver
[ ] Enable HDF barometer sensor driver
[ ] Enable HDF hall sensor driver
[*] Enable HDF storage driver
[ ] Enable HDF USB PNP Notify driver
[ ] Enable F_GENERIC driver
[ ] Enable HDF Audio driver
[*] Enable HDF vibrator driver
[*] Enable HDF linear vibrator driver
[ ] Enable HDF dsoftbus driver
CONFIG_DRIVERS_HDF=y
CONFIG_HDF_SUPPORT_LEVEL=2
CONFIG_DRIVERS_HDF_PLATFORM=y
CONFIG_DRIVERS_HDF_PLATFORM_MIPI_DSI=y
CONFIG_DRIVERS_HDF_PLATFORM_GPIO=y
CONFIG_DRIVERS_HDF_PLATFORM_I2C=y
CONFIG_DRIVERS_HDF_PLATFORM_WATCHDOG=y
CONFIG_PWM_HI35XX=y
CONFIG_DRIVERS_HDF_PLATFORM_PWM=y
CONFIG_DRIVERS_HDF_PLATFORM_UART=y
# CONFIG_DRIVERS_HDF_PLATFORM_SDIO is not set
# CONFIG_DRIVERS_HDF_PLATFORM_EMMC is not set
CONFIG_DRIVERS_HDF_PLATFORM_MMC=y
CONFIG_DRIVERS_HDF_PLATFORM_SPI=y
CONFIG_DRIVERS_HDF_PLATFORM_RTC=y
CONFIG_DRIVERS_HDF_TEST=y
CONFIG_DRIVERS_HDF_DISP=y
# CONFIG_DRIVERS_HDF_LCDKIT is not set
CONFIG_DRIVERS_HDF_LCD_ICN9700=y
# CONFIG_DRIVERS_HDF_LCD_ST7789 is not set
CONFIG_DRIVERS_HDF_INPUT=y
CONFIG_DRIVERS_HDF_TP_5P5_GT911=y
CONFIG_DRIVERS_HDF_TP_2P35_FT6236=y
# CONFIG_DRIVERS_HDF_WIFI is not set
# CONFIG_DRIVERS_HDF_BT is not set
CONFIG_DRIVERS_HDF_SENSOR=y
# CONFIG_DRIVERS_HDF_SENSOR_ACCEL is not set
# CONFIG_DRIVERS_HDF_SENSOR_GYRO is not set
# CONFIG_DRIVERS_HDF_SENSOR_BAROMETER is not set
# CONFIG_DRIVERS_HDF_SENSOR_HALL is not set
CONFIG_DRIVERS_HDF_STORAGE=y
# CONFIG_DRIVERS_HDF_USB_PNP_NOTIFY is not set
# CONFIG_DRIVERS_HDF_USB_F_GENERIC is not set
# CONFIG_DRIVERS_HDF_AUDIO is not set
CONFIG_DRIVERS_HDF_VIBRATOR=y
CONFIG_DRIVERS_HDF_VIBRATOR_LINEAR=y
# CONFIG_DRIVERS_HDF_DSOFTBUS is not set
# end of Device Drivers

[*] Enable HDF linux test 是需要设置的，如果没有设置CONFIG_DRIVERS_HDF_TEST，目录结构就出问题了，会报这样的错误。

drivers/hdf/khdf/Makefile:22: PRODUCT_PATH=vendor/raspberrypi/RPI4B
scripts/Makefile.build:44: drivers/hdf/khdf/../../../../vendor/raspberrypi/RPI4B/hdf_config/Makefile: No such file or directory
make[5]: *** No rule to make target 'drivers/hdf/khdf/../../../../vendor/raspberrypi/RPI4B/hdf_config/Makefile'. Stop.
CC [M] drivers/net/wireless/mac80211_hwsim.o
make[4]: *** [scripts/Makefile.build:497: drivers/hdf/khdf/../../../../vendor/raspberrypi/RPI4B/hdf_config] Error 2
make[3]: *** [scripts/Makefile.build:497: drivers/hdf/khdf] Error 2
make[2]: *** [scripts/Makefile.build:497: drivers/hdf] Error 2
make[2]: *** Waiting for unfinished jobs....

下面3个选项要关闭，不然会报下面的错误。

[ ] Enable HDF platform sdio driver

[ ] Enable HDF platform emmc driver

[ ] Enable HDF wifi

drivers/../../../../../../drivers/adapter/khdf/linux/platform/sdio/sdio_adapter.o: In function `Hi35xxLinuxSdioRescan':
sdio_adapter.c:(.text+0x20): undefined reference to `hisi_sdio_rescan'
sdio_adapter.c:(.text+0x34): undefined reference to `himci_get_mmc_host'
drivers/../../../../../../drivers/adapter/khdf/linux/platform/sdio/sdio_adapter.o: In function `Hi35xxLinuxSdioFindFunc':
sdio_adapter.c:(.text+0xc84): undefined reference to `himci_get_mmc_host'
sdio_adapter.c:(.text+0xc9c): undefined reference to `himci_get_mmc_host'
sdio_adapter.c:(.text+0xcb4): undefined reference to `himci_get_mmc_host'
drivers/../../../../../../drivers/adapter/khdf/linux/platform/emmc/emmc_adapter.o: In function `Hi35xxLinuxEmmcBind':
emmc_adapter.c:(.text+0x214): undefined reference to `himci_get_mmc_host'
drivers/../../../../../../device/hisilicon/drivers/wifi/driver/hi3881/oal/oal_sdio_host.o: In function `sdio_card_detect_change':
oal_sdio_host.c:(.text+0x2ce8): undefined reference to `hisi_sdio_rescan'
make[1]: *** [Makefile:1179: vmlinux] Error 1
make[1]: Leaving directory '/home/liangzili/ohos/out/KERNEL_OBJ/kernel/src_tmp/linux-5.10'
make: *** [kernel.mk:80: /home/liangzili/ohos/out/KERNEL_OBJ/kernel/src_tmp/linux-5.10/arch/arm/boot/zImage] Error 2
ninja: build stopped: subcommand failed.

编译过程

为了方便测试可以单独进行内核编译，比如我的编译命令是这样的。

./build.sh --product-name RPI4B --ccache --build-target raspberrypi_products

可以分析下HDF这部分的编译过程。

linux-5.10\drivers\hdf\Makefile，hdf.patch会添加这个Makefile，将khdf文件夹加入编译。

obj-$(CONFIG_DRIVERS_HDF) += khdf/

linux-5.10\drivers\hdf\khdf\Makefile

export HDF_ROOT := drivers/hdf
obj-$(CONFIG_DRIVERS_HDF) += osal/
obj-$(CONFIG_DRIVERS_HDF) += network/
obj-$(CONFIG_DRIVERS_HDF) += config/
SUPPORT_LEVEL_STD_H := $(shell [ "$(CONFIG_HDF_SUPPORT_LEVEL)" -ge 2 ] && echo true)
$(warning PRODUCT_PATH=$(PRODUCT_PATH)) # 会检查PRODUCT_PATH变量
ifeq ($(PRODUCT_PATH),)
$(error PRODUCT_PATH not)
endif
# 这里有条注释指明了*.hcs配置文件的存放路径
# for L2+, hcs config should in vendor/product_company/product_name/config/khdf
ifeq ($(SUPPORT_LEVEL_STD_H), true)
SUB_DIR:=khdf/
endif
# HDF test的配置会使hcs目录结构不一样，我当时没有设置CONFIG_DRIVERS_HDF_TEST就掉这个坑里了。
ifeq ($(CONFIG_DRIVERS_HDF), y)
ifeq ($(CONFIG_DRIVERS_HDF_TEST), y)
obj-$(CONFIG_DRIVERS_HDF) += ../../../../$(PRODUCT_PATH)/hdf_config/$(SUB_DIR)/hdf_test/
obj-$(CONFIG_DRIVERS_HDF) += test/
else
obj-$(CONFIG_DRIVERS_HDF) += ../../../../$(PRODUCT_PATH)/hdf_config/$(SUB_DIR)
endif
endif
# ... 后面按照配置添加一些编译目录 ...

drivers\adapter\khdf\linux\Makefile：会调用 obj-(CONFIG_DRIVERS_HDF) += ../../../../(CONFIGDRIVERSHDF)+=../../../../(PRODUCT_PATH)/hdf_config/$(SUB_DIR)/hdf_test/ 这是OHOS3.0默认的HCS文件存放路径。官方的注释也说明了，所以将设备对应的*.hcs存放到 vendor\raspberrypi\RPI4B\hdf_config\khdf 文件夹，参考 3516 的 vendor\hisilicon\Hi3516DV300\hdf_config\khdf\hdf.hcs 就可了。

#include "device_info/device_info.hcs"
#include "platform/i2c_config.hcs"
#include "platform/hi35xx_watchdog_config.hcs"
#include "platform/hi35xx_pwm_config.hcs"
#include "platform/hi35xx_uart_config.hcs"
#include "platform/sdio_config.hcs"
#include "platform/emmc_config.hcs"
#include "platform/hi35xx_spi_config.hcs"
#include "input/input_config.hcs"
#include "wifi/wlan_platform.hcs"
#include "wifi/wlan_chip_hi3881.hcs"
#include "sensor/sensor_config.hcs"
#include "audio/audio_config.hcs"
#include "audio/codec_config.hcs"
#include "audio/dai_config.hcs"
#include "audio/dma_config.hcs"
#include "audio/dsp_config.hcs"
#include "vibrator/vibrator_config.hcs"
#include "vibrator/linear_vibrator_config.hcs"
#include "lcd/lcd_config.hcs"
root {
module = "hisilicon,hi35xx_chip";
}

参考 3516 的 vendor\hisilicon\Hi3516DV300\hdf_config\khdf\Makefile

其中：PRODUCT_PATH环境变量的来源：kernel/linux/build/kernel_module_build.sh:42:export PRODUCT_PATH=$4

ifeq ($(LOCAL_HCS_ROOT),)
LOCAL_HCS_ROOT := $(PRODUCT_PATH)
endif
SOURCE_ROOT:=$(abspath ../../../../../)
HC_GEN_DIR := $(abspath $(SOURCE_ROOT)/drivers/framework/tools/hc-gen)
HC_GEN := $(HC_GEN_DIR)/build/hc-gen
LOCAL_HCS_ROOT := $(abspath $(dir $(realpath $(lastword $(MAKEFILE_LIST)))))
HCS_DIR := $(LOCAL_HCS_ROOT)
ifneq ($(TARGET_BOARD_PLATFORM),)
HCS_DIR := $(LOCAL_HCS_ROOT)/$(TARGET_BOARD_PLATFORM)
else
ifneq ($(CONFIG_ARCH_HI3516DV300),)
HCS_DIR := $(LOCAL_HCS_ROOT)
endif
ifneq ($(CONFIG_ARCH_HI3518EV300),)
HCS_DIR := $(LOCAL_HCS_ROOT)
endif
endif
$(info HCS_DIR = $(HCS_DIR))
HCB_FLAGS := -b -i -a
HCS_OBJ := hdf_hcs_hex.o
HCS_OBJ_SRC := $(subst .o,.c,$(notdir $(HCS_OBJ)))
CONFIG_GEN_HEX_SRC := $(addprefix $(LOCAL_HCS_ROOT)/, $(HCS_OBJ_SRC))
CONFIG_HCS_SRC := $(subst _hcs_hex.o,.hcs,$(addprefix $(HCS_DIR)/, $(HCS_OBJ)))
$(obj)/$(HCS_OBJ): $(CONFIG_GEN_HEX_SRC)
$(Q)$(CC) $(c_flags) -c -o $@ $<
$(Q)rm -f $<
$(CONFIG_GEN_HEX_SRC): $(LOCAL_HCS_ROOT)/%_hcs_hex.c: $(HCS_DIR)/%.hcs | $(HC_GEN)
$(Q)echo gen hdf built-in config
$(Q)if [ ! -d $(dir $@) ]; then mkdir -p $(dir $@); fi
$(Q)$(HC_GEN) $(HCB_FLAGS) -o $(subst _hex.c,,$(@)) $<
$(CONFIG_GEN_SRCS): $(CONFIG_OUT_DIR)%.c: $(HCS_DIR)/%.hcs | $(HC_GEN)
$(Q)echo gen hdf driver config
$(Q)if [ ! -d $(dir $@) ]; then mkdir -p $(dir $@); fi
$(Q)$(HC_GEN) -t -o $@ $<
$(HC_GEN):
$(HIDE)make -C $(HC_GEN_DIR)
obj-$(CONFIG_DRIVERS_HDF) += $(HCS_OBJ)