海思35系列平台Tsensor驱动开发（1）驱动编写

1. 前言

3559平台芯片内部内置了温度传感器，可用于实时检测芯片内部温度；

温度的检测范围为-40~125℃，支持设置温度上下限阈值报警输出。内部温度传感器提供了单次采集模式和循环采集模式两种选择。

软件开发分为驱动和用户态软件开发。

2. 查看芯片datasheet

3. 驱动软件编写

这里使用混杂设备进行驱动编写；

misc_register(&hitsensor_dev)；

以下就是具体功能实现，主要根据芯片datasheet转化过来；

（1）设置温度采集模式

copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));                
SYS_READ(tsensor_reg_base+0x70);   //MISC_CTRL28
if(hitsensor_info.value == 1)
{
    reg_data |= 1 << 30;
}   
else
{
    reg_data &= ~(1 << 30);
}
SYS_WRITEL(tsensor_reg_base+0x70, reg_data); 

（2）设置温度采集周期

copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));
                tmp = (hitsensor_info.value >> 1) | 0x1;
                tmp = tmp & 0xFF;
                reg_data = SYS_READ(tsensor_reg_base+0x70);             //MISC_CTRL28
                reg_data &= 0xF0FFFFFF;
                reg_data |= tmp << 20;                          
                SYS_WRITEL(tsensor_reg_base+0x70, reg_data); 

（3）设置温度报警上限阈值

copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));
                reg_data = (hitsensor_info.value&0x3FF) << 10;
                SYS_WRITEL(tsensor_reg_base+0x70, reg_data); 

（4）设置温度报警下线阈值

                copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));
                reg_data = SYS_READ(tsensor_reg_base+0x70);
                reg_data |= hitsensor_info.value&0x3FF;
                SYS_WRITEL(tsensor_reg_base+0x70, reg_data);  

（5）使能启动温度采集

copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));                
                reg_data = SYS_READ(tsensor_reg_base+0x70);     //MISC_CTRL28
                if(hitsensor_info.value == 1)
                {
                    reg_data |= 1 << 31;
                }   
                else
                {
                    reg_data &= ~(1 << 31);
                }
                SYS_WRITEL(tsensor_reg_base+0x70, reg_data);

（6）读取CPU温度值

copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));
                tmp = SYS_READ(tsensor_reg_base+0x78);      //MISC_CTRL30
                hitsensor_info.value = tmp & 0x3FF;         
                copy_to_user((void __user *)arg, &hitsensor_info, sizeof(Hi_Tsensor_info));
            }

（7）读取温度报警上限标志

copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));        
                tmp = SYS_READ(tsensor_reg_base+0x74);              //MISC_CTRL29
                hitsensor_info.value = tmp & 0x1;
                copy_to_user((void __user *)arg, &hitsensor_info, sizeof(Hi_Tsensor_info));

（8）读取温度报警下限标志

    copy_from_user(&hitsensor_info, (Hi_Tsensor_info*)arg, sizeof(Hi_Tsensor_info));                    
                tmp = SYS_READ(tsensor_reg_base+0x74);        //MISC_CTRL29
                hitsensor_info.value = (tmp >> 1) & 0x1;
                copy_to_user((void __user *)arg, &hitsensor_info, sizeof(Hi_Tsensor_info));

至此驱动的具体功能都已实现

4. 驱动编译

这里驱动可以不放在内核编译；
可以参考35xx平台的驱动编译方式；
路径如下：
drv/interdrv/sysconfig 【以sysconfig驱动为例】
参考这个Makefile即可

指定内核路径：
KERNELDIR ?=/xxx/osdrv/opensource/kernel/linux-4.9.y_multi-core

指定交叉工具链：
CROSS_COMPILE ?=aarch64-himix100-linux-

完整Makefile如下

DRIVER_NAME = hi_tsensor

PWD       = $(shell pwd)
export ARCH=arm64

CROSS_COMPILE   ?=aarch64-himix100-linux-

#KERNELDIR ?= /lib/modules/$(shell uname -r)/build
KERNELDIR ?=/xxx/xxx/osdrv/opensource/kernel/linux-4.9.y_multi-core
EXE                     = $(DRIVER_NAME).ko

obj-m := $(DRIVER_NAME).o
hi_tsensor-objs := Hi_Tsensor.o

.PHONY: all
all:
        @echo "  Making $@ ..."
ifneq ($(CROSS_COMPILE),)
        $(MAKE)  CROSS_COMPILE=$(CROSS_COMPILE) -C $(KERNELDIR) M=$(PWD) modules
else
        $(MAKE) -C $(KERNELDIR) M=$(PWD) modules
endif
ifneq ($(OUT),)
        cp -f $(EXE) $(OUT)/
endif
ifneq ($(INC),)
        cp -f *.h $(INC)/
endif

.PHONY: clean
clean:
        rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions modules.order Module.symvers *.ko.unsigned

depend .depend dep:
        $(CC) $(CFLAGS) -M *.c > .depend

ifeq (.depend,$(wildcard .depend))
        include .depend
endif

编译完成，生成驱动ko文件