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【驱动篇】龙芯LS2K0300之ADC驱动

news 2025/7/7 13:38:47

实验目的

由于LS2K0300久久派开发板4.19内核还没有现成可用的ADC驱动，但是龙芯官方的5.10内核已经提供了ADC驱动，想要在4.19内核使用ADC就要参考5.10内核移植驱动，本次实验主要是关于ADC驱动的移植和使用

驱动移植

主要的驱动代码主要有3个：loongson-2k300-adc.c、loongson-2k300-adc-core.c、loongson-2k300-adc-core.h，位于drivers/iio/adc目录下

loongson-2k300-adc.c

这个是platform_driver代码部分

#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/delay.h>
#include "loongson-2k300-adc-core.h"#define ADC_DATA_MASK 0x0FFF#define ADC_MAX_VOLTAGE 1800
#define ADC_SCALE 4096struct ls2k300_adc_data {void __iomem *base;spinlock_t read_raw_lock; // 添加读取的自旋锁 扫描模式，单次读取时使用
};// 这里是有节点可以读取的关键
#define LS2K300_CHANNEL(num) { \.type = IIO_VOLTAGE, \.indexed = 1, \.channel = num, \.address = ADC_DR, \.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \.scan_index = num, \.scan_type = { \.sign = 's', \.realbits = 12, \.storagebits = 16, \.shift = 12, \.endianness = IIO_CPU, \}, \
}static const struct iio_chan_spec ls2k300_adc_channels[] = {IIO_CHAN_SOFT_TIMESTAMP(8),LS2K300_CHANNEL(0),LS2K300_CHANNEL(1),LS2K300_CHANNEL(2),LS2K300_CHANNEL(3),LS2K300_CHANNEL(4),LS2K300_CHANNEL(5),LS2K300_CHANNEL(6),LS2K300_CHANNEL(7),// 注入通道// { .type = IIO_VOLTAGE, .differential = 1, .channel = 0, .address = ADC_JDR1 },// { .type = IIO_VOLTAGE, .differential = 1, .channel = 1, .address = ADC_JDR2 },// { .type = IIO_VOLTAGE, .differential = 1, .channel = 2, .address = ADC_JDR3 },// { .type = IIO_VOLTAGE, .differential = 1, .channel = 3, .address = ADC_JDR4 },
};// sysfs 下的节点读取时的具体调用函数
static int ls2k300_adc_read_raw(struct iio_dev *indio_dev,struct iio_chan_spec const *chan,int *val, int *val2, long mask)
{struct ls2k300_adc_data *data = iio_priv(indio_dev);unsigned int reg_offset;unsigned long flags;switch (mask) {case IIO_CHAN_INFO_RAW:// 针对 in_voltagex_raw 节点if (chan->differential) {reg_offset = chan->address;} else {reg_offset = chan->address;}// 由于规则通道组只有一个通道，所以这里需要用锁来限定一段时间只能读取一个通道的值。spin_lock_irqsave(&data->read_raw_lock, flags);ADC_RegularChannelConfig(data->base, chan->channel, 1, ADC_SampleTime_64Cycles);adc_software_start_conv_trigger(data->base, ENABLE, 0);adc_eoc_check_conv_end(data->base);*val = ioread16(data->base + reg_offset) & ADC_DATA_MASK;spin_unlock_irqrestore(&data->read_raw_lock, flags);return IIO_VAL_INT;case IIO_CHAN_INFO_SCALE:// 针对 in_voltagex_scale 节点*val = ADC_MAX_VOLTAGE;*val2 = ADC_SCALE;// 返回的值就是 val1 / val2 的那个小数值// scale * raw 就是对应的电压值，单位mVreturn IIO_VAL_FRACTIONAL;default:return -EINVAL;}
}static const struct iio_info ls2k300_adc_info = {.read_raw = ls2k300_adc_read_raw,
};static int ls2k300_adc_probe(struct platform_device *pdev)
{adc_init_info adc_init_struct;struct iio_dev *indio_dev;struct ls2k300_adc_data *data;struct resource *res;int ret;indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*data));if (!indio_dev) {dev_err(&pdev->dev, "devm_iio_device_alloc failed! probe failed!\n");return -ENOMEM;}data = iio_priv(indio_dev);res = platform_get_resource(pdev, IORESOURCE_MEM, 0);data->base = devm_ioremap_resource(&pdev->dev, res);if (IS_ERR(data->base)) {dev_err(&pdev->dev, "devm_ioremap_resource failed! probe failed! (base: %.llx)\n", (unsigned long long)data->base);return PTR_ERR(data->base);}// 配置 ADC CR1 和 CR2 等寄存器，具体配置根据需要调整// 不使用 DMA, 扫描模式, 单次，规则序列转化数为1, 也就是每次都等待读取完毕。// EOC中断和JEOC中断没开adc_struct_init(&adc_init_struct);adc_init_struct.ADC_Mode = ADC_Mode_Independent;adc_init_struct.ADC_ScanConvMode = ENABLE;adc_init_struct.ADC_ContinuousConvMode = DISABLE;adc_init_struct.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;adc_init_struct.ADC_DataAlign = ADC_DataAlign_Right;adc_init_struct.ADC_NbrOfChannel = 1; //规则通道数量 为 1，这是一个一个的触发 扫描模式的单次扫描adc_init_struct.ADC_ClkDivider = 1;  //Loongson Featureadc_init_struct.ADC_JTrigMod = 0;    //Loongson Featureadc_init_struct.ADC_ADCEdge = 0;     //Loongson Featureadc_init_struct.ADC_DiffMod = 0;     //Loongson Featureadc_init(data->base, &adc_init_struct);adc_dev_enable(data->base, ENABLE);// iio 框架信息注册indio_dev->dev.parent = &pdev->dev;indio_dev->info = &ls2k300_adc_info;indio_dev->name = pdev->name;indio_dev->modes = INDIO_DIRECT_MODE;indio_dev->channels = ls2k300_adc_channels;indio_dev->num_channels = ARRAY_SIZE(ls2k300_adc_channels);spin_lock_init(&data->read_raw_lock); // 初始化自旋锁ret = iio_device_register(indio_dev);if (ret) {dev_err(&pdev->dev, "iio_device_register failed! probe failed! (ret: %d)\n", ret);return ret;}platform_set_drvdata(pdev, indio_dev);dev_info(&pdev->dev, "ADC Device registered successfully\n");return 0;
}static int ls2k300_adc_remove(struct platform_device *pdev)
{struct iio_dev *indio_dev = platform_get_drvdata(pdev);iio_device_unregister(indio_dev);return 0;
}static const struct of_device_id ls2k300_adc_of_match[] = {{ .compatible = "ls2k300-adc", },{ }
};
MODULE_DEVICE_TABLE(of, ls2k300_adc_of_match);static struct platform_driver ls2k300_adc_driver = {.driver = {.name = "ls2k300_adc",.of_match_table = ls2k300_adc_of_match,},.probe = ls2k300_adc_probe,.remove = ls2k300_adc_remove,
};
module_platform_driver(ls2k300_adc_driver);MODULE_AUTHOR("oujintao qujintao@loongson.cn");
MODULE_DESCRIPTION("2k300 ADC IIO driver");
MODULE_LICENSE("GPL");

loongson-2k300-adc-core.c

这个是关于ADC的操作部分驱动代码：主要是读写寄存器

#include <linux/module.h>
#include <linux/delay.h>
#include "loongson-2k300-adc-core.h"#define ADC_DATA_MASK       0x0FFF/*******************************************************************************
* Function Name  : adc_init
* Description    : Initializes the ADCx peripheral according to the specified parameters
*                  in the ADC_InitStruct.
* Input          : - ADCx: where x can be 1, 2 or 3 to select the ADC peripheral.
*                  - ADC_InitStruct: pointer to an adc_init_info structure that
*                    contains the configuration information for the specified
*                    ADC peripheral.
* Output         : None
* Return         : None
******************************************************************************/
void adc_init(adc_reg_map* ADCx, adc_init_info* ADC_InitStruct)
{unsigned int temp_val_1 = 0;unsigned int temp_val_2 = 0;/*---------------------------- ADCx CR1 Configuration -----------------*//* Get the ADCx CR1 value */temp_val_1 = ADCx->CR1;/* Clear DUALMOD and SCAN bits */temp_val_1 &= CR1_CLEAR_MASK;/* Configure ADCx: Dual mode and scan conversion mode *//* Set DUALMOD bits according to ADC_Mode value *//* Set SCAN bit according to ADC_ScanConvMode value */temp_val_1 |= (unsigned int)(ADC_InitStruct->ADC_Mode | ((unsigned int)ADC_InitStruct->ADC_ScanConvMode << 8) |((unsigned int)((ADC_InitStruct->ADC_ClkDivider)&0x3f) << 24)  |((unsigned int)ADC_InitStruct->ADC_DiffMod << 20) |((unsigned int)ADC_InitStruct->ADC_OutPhaseSel << 30)); //ygtemp_val_1 |= 1 << CR1_EOC_IE_OFFSET;temp_val_1 ^= 1 << CR1_EOC_IE_OFFSET;temp_val_1 |= ADC_InitStruct->ADC_Int_EOC << CR1_EOC_IE_OFFSET;temp_val_1 |= 1 << CR1_J_EOC_IE_OFFSET;temp_val_1 ^= 1 << CR1_J_EOC_IE_OFFSET;temp_val_1 |= ADC_InitStruct->ADC_Int_JEOC << CR1_J_EOC_IE_OFFSET;/* Write to ADCx CR1 */ADCx->CR1 = temp_val_1;/*---------------------------- ADCx CR2 Configuration -----------------*//* Get the ADCx CR2 value */temp_val_1 = ADCx->CR2;/* Clear CONT, ALIGN and EXTSEL bits */temp_val_1 &= CR2_CLEAR_MASK;/* Configure ADCx: external trigger event and continuous conversion mode *//* Set ALIGN bit according to ADC_DataAlign value *//* Set EXTSEL bits according to ADC_ExternalTrigConv value *//* Set CONT bit according to ADC_ContinuousConvMode value */temp_val_1 |= (unsigned int)(ADC_InitStruct->ADC_DataAlign | ADC_InitStruct->ADC_ExternalTrigConv |((unsigned int)ADC_InitStruct->ADC_ContinuousConvMode << 1) |((unsigned int)ADC_InitStruct->ADC_JTrigMod << 24) | //yg((unsigned int)(((ADC_InitStruct->ADC_ClkDivider)>>6)&0xf) << 26)  |((unsigned int)ADC_InitStruct->ADC_ADCEdge << 30)  |((unsigned int)ADC_InitStruct->ADC_ClkMask << 31)) ; //yg/* Write to ADCx CR2 */ADCx->CR2 = temp_val_1;/*---------------------------- ADCx SQR1 Configuration -----------------*//* Get the ADCx SQR1 value */temp_val_1 = ADCx->SQR1;/* Clear L bits */temp_val_1 &= SQR1_CLEAR_MASK;/* Configure ADCx: regular channel sequence length *//* Set L bits according to ADC_NbrOfChannel value */temp_val_2 |= (ADC_InitStruct->ADC_NbrOfChannel - 1);temp_val_1 |= ((unsigned int)temp_val_2 << 20);/* Write to ADCx SQR1 */ADCx->SQR1 = temp_val_1;
}/*******************************************************************************
* Function Name  : adc_struct_init
* Description    : Fills each ADC_InitStruct member with its default value.
* Input          : ADC_InitStruct : pointer to an adc_init_info structure
*                  which will be initialized.
* Output         : None
* Return         : None
*******************************************************************************/
void adc_struct_init(adc_init_info* ADC_InitStruct)
{/* Reset ADC init structure parameters values *//* Initialize the ADC_Mode member */ADC_InitStruct->ADC_Mode = ADC_Mode_Independent;/* initialize the ADC_ScanConvMode member */ADC_InitStruct->ADC_ScanConvMode = DISABLE;/* Initialize the ADC_ContinuousConvMode member */ADC_InitStruct->ADC_ContinuousConvMode = DISABLE;/* Initialize the ADC_ExternalTrigConv member */ADC_InitStruct->ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;/* Initialize the ADC_DataAlign member */ADC_InitStruct->ADC_DataAlign = ADC_DataAlign_Right;/* Initialize the ADC_NbrOfChannel member */ADC_InitStruct->ADC_NbrOfChannel = 1;/* Initialize the ADC_ClkDivider member */ADC_InitStruct->ADC_ClkDivider = 0xff;/* Initialize the ADC_JTrigMod member */ADC_InitStruct->ADC_JTrigMod = 0;/* Initialize the ADC_ADCEdge member */ADC_InitStruct->ADC_ADCEdge = 0;/* Initialize the ADC_DIFFMOD member */ADC_InitStruct->ADC_DiffMod = 0;/* Initialize the ADC_OutPhaseSel member */ADC_InitStruct->ADC_OutPhaseSel = 0;/* Initialize the ADC_ClkMask member */ADC_InitStruct->ADC_ClkMask = 0;/* Initialize CR1 EOC disable */ADC_InitStruct->ADC_Int_EOC = DISABLE;/* Initialize CR1 EOC disable */ADC_InitStruct->ADC_Int_JEOC = DISABLE;
}void ADC_RegularChannelConfig(adc_reg_map* ADCx, unsigned char ADC_Channel, unsigned char Rank, unsigned char ADC_SampleTime)
{unsigned int temp_val_1 = 0, temp_val_2 = 0;/* if ADC_Channel_10 ... ADC_Channel_17 is selected */if (ADC_Channel > ADC_Channel_9) {/* Get the old register value */temp_val_1 = ADCx->SMPR1;/* Calculate the mask to clear */temp_val_2 = SMPR1_SMP_MASK << (3 * (ADC_Channel - 10));/* Clear the old discontinuous mode channel count */temp_val_1 &= ~temp_val_2;/* Calculate the mask to set */temp_val_2 = (unsigned int)ADC_SampleTime << (3 * (ADC_Channel - 10));/* Set the discontinuous mode channel count */temp_val_1 |= temp_val_2;/* Store the new register value */ADCx->SMPR1 = temp_val_1;} else { /* ADC_Channel include in ADC_Channel_[0..9] *//* Get the old register value */temp_val_1 = ADCx->SMPR2;/* Calculate the mask to clear */temp_val_2 = SMPR2_SMP_MASK << (3 * ADC_Channel);/* Clear the old discontinuous mode channel count */temp_val_1 &= ~temp_val_2;/* Calculate the mask to set */temp_val_2 = (unsigned int)ADC_SampleTime << (3 * ADC_Channel);/* Set the discontinuous mode channel count */temp_val_1 |= temp_val_2;/* Store the new register value */ADCx->SMPR2 = temp_val_1;}/* For Rank 1 to 6 */if (Rank < 7) {/* Get the old register value */temp_val_1 = ADCx->SQR3;/* Calculate the mask to clear */temp_val_2 = SQR3_SQ_MASK << (5 * (Rank - 1));/* Clear the old SQx bits for the selected rank */temp_val_1 &= ~temp_val_2;/* Calculate the mask to set */temp_val_2 = (unsigned int)ADC_Channel << (5 * (Rank - 1));/* Set the SQx bits for the selected rank */temp_val_1 |= temp_val_2;/* Store the new register value */ADCx->SQR3 = temp_val_1;} else if (Rank < 13) { /* For Rank 7 to 12 *//* Get the old register value */temp_val_1 = ADCx->SQR2;/* Calculate the mask to clear */temp_val_2 = SQR2_SQ_MASK << (5 * (Rank - 7));/* Clear the old SQx bits for the selected rank */temp_val_1 &= ~temp_val_2;/* Calculate the mask to set */temp_val_2 = (unsigned int)ADC_Channel << (5 * (Rank - 7));/* Set the SQx bits for the selected rank */temp_val_1 |= temp_val_2;/* Store the new register value */ADCx->SQR2 = temp_val_1;} else { /* For Rank 13 to 16 *//* Get the old register value */temp_val_1 = ADCx->SQR1;/* Calculate the mask to clear */temp_val_2 = SQR1_SQ_MASK << (5 * (Rank - 13));/* Clear the old SQx bits for the selected rank */temp_val_1 &= ~temp_val_2;/* Calculate the mask to set */temp_val_2 = (unsigned int)ADC_Channel << (5 * (Rank - 13));/* Set the SQx bits for the selected rank */temp_val_1 |= temp_val_2;/* Store the new register value */ADCx->SQR1 = temp_val_1;}
}/*******************************************************************************
* Function Name  : adc_dev_enable
* Description    : Enables or disables the specified ADC peripheral.
* Input          : - ADCx: where x can be 1, 2 or 3 to select the ADC peripheral.
*                  - state: new state of the ADCx peripheral. This parameter
*                    can be: ENABLE or DISABLE.
* Output         : None
* Return         : None
*******************************************************************************/
void adc_dev_enable(adc_reg_map* ADCx, FunctionalState state)
{unsigned int temp;if (state == ENABLE) {temp = ADCx->CR2;temp |= 1 << CR2_ADON_OFFSET;temp ^= 1 << CR2_ADON_OFFSET;temp |= (state << CR2_ADON_OFFSET);ADCx->CR2 = temp;// 触发复位校准和AD校准ADCx->CR2 = temp;temp = ADCx->CR2;temp |= (state << 2) | (state << 3);ADCx->CR2 = temp;
#if 0while (1) {temp = ADCx->CR2;temp &= 1 << 2;if (!temp)break;}
#elsendelay(1000000);
#endif} else {temp = ADCx->CR2;temp |= 1 << CR2_ADON_OFFSET;temp ^= 1 << CR2_ADON_OFFSET;ADCx->CR2 = temp;}
}/*******************************************************************************
* Function Name  : adc_software_start_conv_trigger
* Description    : Enables or disables the selected ADC software start conversion .
* Input          : - ADCx: where x can be 1, 2 or 3 to select the ADC peripheral.
*                  - state: new state of the selected ADC software start conversion.
*                    This parameter can be: ENABLE or DISABLE.
* Output         : None
* Return         : None
*******************************************************************************/
void adc_software_start_conv_trigger(adc_reg_map* ADCx, FunctionalState state, unsigned char J_channel)
{unsigned int temp;unsigned char EOC_offset;unsigned char start_offset;unsigned char exttrig_offset;EOC_offset = J_channel ? SR_J_EOC_OFFSET : SR_EOC_OFFSET;start_offset = J_channel ? CR2_EXTTRIG_SW_J_START_OFFSET : CR2_EXTTRIG_SW_START_OFFSET;exttrig_offset = J_channel ? CR2_J_EXTTRIG_OFFSET : CR2_EXTTRIG_OFFSET;if (state == ENABLE) {temp = ADCx->CR2;temp |= 1 << exttrig_offset;ADCx->CR2 = temp;// 先把 EOC 清除temp = ADCx->SR;temp |= 1 << EOC_offset;temp ^= 1 << EOC_offset;ADCx->SR = temp;ADCx->CR2 |= 1 << start_offset;} else {/* Disable the selected ADC conversion on external event and stop the selected ADC conversion */temp = ADCx->CR2;temp |= 1 << start_offset;temp ^= 1 << start_offset;ADCx->CR2 = temp;}
}void adc_eoc_check_conv_end(adc_reg_map* ADCx)
{int max_loop;unsigned int temp;max_loop = 0;while (1) {temp = ADCx->SR;temp &= 1 << 1;ndelay(10);++max_loop;if (temp == 2)break;if (max_loop == 10000) {pr_info("adc_eoc_check_conv_end eoc wait timeout\n");break;}}
}

loongson-2k300-adc-core.h

头文件部分：主要是定义一些ADC相关的寄存器宏和结构体

#ifndef __LOONGSON_2K300_ADC_CORE_H__
#define __LOONGSON_2K300_ADC_CORE_H__typedef enum FunctionalState {DISABLE = 0,ENABLE,
} FunctionalState;// ADC register offsets
#define ADC_SR              0x00
#define ADC_CR1             0x04
#define ADC_CR2             0x08
#define ADC_SMPR1           0x0C
#define ADC_SMPR2           0x10
#define ADC_JOFR1           0x14
#define ADC_JOFR2           0x18
#define ADC_JOFR3           0x1C
#define ADC_JOFR4           0x20
#define ADC_HTR             0x24
#define ADC_LTR             0x28
#define ADC_SQR1            0x2C
#define ADC_SQR2            0x30
#define ADC_SQR3            0x34
#define ADC_JSQR            0x38
#define ADC_JDR1            0x3C
#define ADC_JDR2            0x40
#define ADC_JDR3            0x44
#define ADC_JDR4            0x48
#define ADC_DR              0x4Ctypedef struct
{volatile unsigned int SR;volatile unsigned int CR1;volatile unsigned int CR2;volatile unsigned int SMPR1;volatile unsigned int SMPR2;volatile unsigned int JOFR1;volatile unsigned int JOFR2;volatile unsigned int JOFR3;volatile unsigned int JOFR4;volatile unsigned int HTR;volatile unsigned int LTR;volatile unsigned int SQR1;volatile unsigned int SQR2;volatile unsigned int SQR3;volatile unsigned int JSQR;volatile unsigned int JDR1;volatile unsigned int JDR2;volatile unsigned int JDR3;volatile unsigned int JDR4;volatile unsigned int DR;
} adc_reg_map;/******************** (C) COPYRIGHT 2008 STMicroelectronics ********************
* File Name          : stm32f10x_adc.h
* Author             : MCD Application Team
* Version            : V2.0.3
* Date               : 09/22/2008
* Description        : This file contains all the functions prototypes for the
*                      ADC firmware library.
********************************************************************************
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
* AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
* INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
* CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
* INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*******************************************************************************//* Define to prevent recursive inclusion -------------------------------------*/#define   ADC_RCG     (12)/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* ADC DISCNUM mask */
// #define CR1_DISCNUM_Reset           ((unsigned int)0xFFFF1FFF)// /* ADC DISCEN mask */
// #define CR1_DISCEN_Set              ((unsigned int)0x00000800)
// #define CR1_DISCEN_Reset            ((unsigned int)0xFFFFF7FF)// /* ADC JAUTO mask */
// #define CR1_JAUTO_Set               ((unsigned int)0x00000400)
// #define CR1_JAUTO_Reset             ((unsigned int)0xFFFFFBFF)// /* ADC JDISCEN mask */
// #define CR1_JDISCEN_Set             ((unsigned int)0x00001000)
// #define CR1_JDISCEN_Reset           ((unsigned int)0xFFFFEFFF)// /* ADC AWDCH mask */
// #define CR1_AWDCH_Reset             ((unsigned int)0xFFFFFFE0)// /* ADC Analog watchdog enable mode mask */
// #define CR1_AWDMode_Reset           ((unsigned int)0xFF3FFDFF)// /* CR1 register Mask */
#define CR1_CLEAR_MASK              ((unsigned int)0xFFF0FEFF)//
#define SR_EOC_OFFSET 0x1
#define SR_J_EOC_OFFSET 0x2//
#define CR1_EOC_IE_OFFSET 0x5
#define CR1_J_EOC_IE_OFFSET 0x7/* ADC ADON mask */
#define CR2_ADON_OFFSET             0x0/* ADC reset */
// #define CR2_ADC_Reset               ((unsigned int)0x80000000)// /* ADC DMA mask */
// #define CR2_DMA_Set                 ((unsigned int)0x00000100)
// #define CR2_DMA_Reset               ((unsigned int)0xFFFFFEFF)// /* ADC RSTCAL mask */
// #define CR2_RSTCAL_Set              ((unsigned int)0x00000008)// /* ADC CAL mask */
// #define CR2_CAL_Set                 ((unsigned int)0x00000004)// /* ADC SWSTART mask */
// #define CR2_SWSTART_Set             ((unsigned int)0x00400000)// /* ADC EXTTRIG mask */
// #define CR2_EXTTRIG_Set             ((unsigned int)0x00100000)
// #define CR2_EXTTRIG_Reset           ((unsigned int)0xFFEFFFFF)/* ADC Software start mask */
#define CR2_EXTTRIG_SW_START_OFFSET 22
#define CR2_EXTTRIG_SW_J_START_OFFSET 21
#define CR2_EXTTRIG_OFFSET 20
#define CR2_J_EXTTRIG_OFFSET 15
// #define CR2_EXTTRIG_SWSTART_Set     ((unsigned int)0x00500000)
// #define CR2_EXTTRIG_SWSTART_Reset   ((unsigned int)0xFFAFFFFF)/* ADC JEXTSEL mask */
// #define CR2_JEXTSEL_Reset           ((unsigned int)0xFFFF8FFF)// /* ADC JEXTTRIG mask */
// #define CR2_JEXTTRIG_Set            ((unsigned int)0x00008000)
// #define CR2_JEXTTRIG_Reset          ((unsigned int)0xFFFF7FFF)// /* ADC JSWSTART mask */
// #define CR2_JSWSTART_Set            ((unsigned int)0x00200000)// /* ADC injected software start mask */
// #define CR2_JEXTTRIG_JSWSTART_Set   ((unsigned int)0x00208000)
// #define CR2_JEXTTRIG_JSWSTART_Reset ((unsigned int)0xFFDF7FFF)// /* ADC TSPD mask */
// #define CR2_TSVREFE_Set             ((unsigned int)0x00800000)
// #define CR2_TSVREFE_Reset           ((unsigned int)0xFF7FFFFF)// /* CR2 register Mask */
#define CR2_CLEAR_MASK              ((unsigned int)0xFFF1F7FD)// /* ADC SQx mask */
#define SQR3_SQ_MASK 0x1F
#define SQR2_SQ_MASK 0x1F
#define SQR1_SQ_MASK 0x1F// /* SQR1 register Mask */
#define SQR1_CLEAR_MASK             ((unsigned int)0xFF0FFFFF)// /* ADC JSQx mask */
// #define JSQR_JSQ_Set                ((unsigned int)0x0000001F)// /* ADC JL mask */
// #define JSQR_JL_Set                 ((unsigned int)0x00300000)
// #define JSQR_JL_Reset               ((unsigned int)0xFFCFFFFF)// /* ADC SMPx mask */
#define SMPR1_SMP_MASK 0x7
#define SMPR2_SMP_MASK 0x7// /* ADC JDRx registers offset */
// #define JDR_Offset                  ((unsigned char)0x28)// #define DISABLE 0
// #define ENABLE 1/* Includes ------------------------------------------------------------------*/
// #include "../i2c/ls2k0300_map.h"/* Exported types ------------------------------------------------------------*/
/* ADC Init structure definition */
typedef struct
{unsigned int ADC_Mode;int ADC_ScanConvMode;  //CR1 scanint ADC_ContinuousConvMode;//CR2 contunsigned int ADC_ExternalTrigConv;//CR2 extselunsigned int ADC_DataAlign;//CR2 alignunsigned char  ADC_NbrOfChannel;//SQR1 lunsigned short ADC_ClkDivider;//CR1 clkdivunsigned char  ADC_JTrigMod;//CR2 jtrigmodunsigned char  ADC_ADCEdge;//CR2 adcedgeunsigned char  ADC_DiffMod;//CR1 diffmodunsigned char  ADC_OutPhaseSel;//CR1 opsunsigned char  ADC_ClkMask;//CR2 clkmaskunsigned char ADC_Int_EOC; // CR1 EOC enable ?unsigned char ADC_Int_JEOC; // CR1 JEOC enable ?
}adc_init_info;/* Exported constants --------------------------------------------------------*//* ADC dual mode -------------------------------------------------------------*/
#define ADC_Mode_Independent                       ((unsigned int)0x00000000)
#define ADC_Mode_RegInjecSimult                    ((unsigned int)0x00010000)
#define ADC_Mode_RegSimult_AlterTrig               ((unsigned int)0x00020000)
#define ADC_Mode_InjecSimult_FastInterl            ((unsigned int)0x00030000)
#define ADC_Mode_InjecSimult_SlowInterl            ((unsigned int)0x00040000)
#define ADC_Mode_InjecSimult                       ((unsigned int)0x00050000)
#define ADC_Mode_RegSimult                         ((unsigned int)0x00060000)
#define ADC_Mode_FastInterl                        ((unsigned int)0x00070000)
#define ADC_Mode_SlowInterl                        ((unsigned int)0x00080000)
#define ADC_Mode_AlterTrig                         ((unsigned int)0x00090000)#define IS_ADC_MODE(MODE) (((MODE) == ADC_Mode_Independent) || \((MODE) == ADC_Mode_RegInjecSimult) || \((MODE) == ADC_Mode_RegSimult_AlterTrig) || \((MODE) == ADC_Mode_InjecSimult_FastInterl) || \((MODE) == ADC_Mode_InjecSimult_SlowInterl) || \((MODE) == ADC_Mode_InjecSimult) || \((MODE) == ADC_Mode_RegSimult) || \((MODE) == ADC_Mode_FastInterl) || \((MODE) == ADC_Mode_SlowInterl) || \((MODE) == ADC_Mode_AlterTrig))/* ADC extrenal trigger sources for regular channels conversion --------------*/
/* for ADC1 and ADC2 */
#define ADC_ExternalTrigConv_T1_CC1                ((unsigned int)0x00000000)
#define ADC_ExternalTrigConv_T1_CC2                ((unsigned int)0x00020000)
#define ADC_ExternalTrigConv_T2_CC2                ((unsigned int)0x00060000)
#define ADC_ExternalTrigConv_T3_TRGO               ((unsigned int)0x00080000)
#define ADC_ExternalTrigConv_T4_CC4                ((unsigned int)0x000A0000)
#define ADC_ExternalTrigConv_Ext_IT11_TIM8_TRGO    ((unsigned int)0x000C0000)
/* for ADC1, ADC2 and ADC3 */
#define ADC_ExternalTrigConv_T1_CC3                ((unsigned int)0x00040000)
#define ADC_ExternalTrigConv_None                  ((unsigned int)0x000E0000)
/* for ADC3 */
#define ADC_ExternalTrigConv_T3_CC1                ((unsigned int)0x00000000)
#define ADC_ExternalTrigConv_T2_CC3                ((unsigned int)0x00020000)
#define ADC_ExternalTrigConv_T8_CC1                ((unsigned int)0x00060000)
#define ADC_ExternalTrigConv_T8_TRGO               ((unsigned int)0x00080000)
#define ADC_ExternalTrigConv_T5_CC1                ((unsigned int)0x000A0000)
#define ADC_ExternalTrigConv_T5_CC3                ((unsigned int)0x000C0000)#define IS_ADC_EXT_TRIG(REGTRIG) (((REGTRIG) == ADC_ExternalTrigConv_T1_CC1) || \((REGTRIG) == ADC_ExternalTrigConv_T1_CC2) || \((REGTRIG) == ADC_ExternalTrigConv_T1_CC3) || \((REGTRIG) == ADC_ExternalTrigConv_T2_CC2) || \((REGTRIG) == ADC_ExternalTrigConv_T3_TRGO) || \((REGTRIG) == ADC_ExternalTrigConv_T4_CC4) || \((REGTRIG) == ADC_ExternalTrigConv_Ext_IT11_TIM8_TRGO) || \((REGTRIG) == ADC_ExternalTrigConv_None) || \((REGTRIG) == ADC_ExternalTrigConv_T3_CC1) || \((REGTRIG) == ADC_ExternalTrigConv_T2_CC3) || \((REGTRIG) == ADC_ExternalTrigConv_T8_CC1) || \((REGTRIG) == ADC_ExternalTrigConv_T8_TRGO) || \((REGTRIG) == ADC_ExternalTrigConv_T5_CC1) || \((REGTRIG) == ADC_ExternalTrigConv_T5_CC3))/* ADC data align ------------------------------------------------------------*/
#define ADC_DataAlign_Right                        ((unsigned int)0x00000000)
#define ADC_DataAlign_Left                         ((unsigned int)0x00000800)#define IS_ADC_DATA_ALIGN(ALIGN) (((ALIGN) == ADC_DataAlign_Right) || \((ALIGN) == ADC_DataAlign_Left))/* ADC channels --------------------------------------------------------------*/
#define ADC_Channel_0                               ((unsigned char)0x00)
#define ADC_Channel_1                               ((unsigned char)0x01)
#define ADC_Channel_2                               ((unsigned char)0x02)
#define ADC_Channel_3                               ((unsigned char)0x03)
#define ADC_Channel_4                               ((unsigned char)0x08)
#define ADC_Channel_5                               ((unsigned char)0x09)
#define ADC_Channel_6                               ((unsigned char)0x0a)
#define ADC_Channel_7                               ((unsigned char)0x0b)
#define ADC_Channel_8                               ((unsigned char)0x18)
#define ADC_Channel_9                               ((unsigned char)0x19)
#define ADC_Channel_10                              ((unsigned char)0x1A)
#define ADC_Channel_11                              ((unsigned char)0x1B)
#define ADC_Channel_12                              ((unsigned char)0x1C)
#define ADC_Channel_13                              ((unsigned char)0x1D)
#define ADC_Channel_14                              ((unsigned char)0x1E)
#define ADC_Channel_15                              ((unsigned char)0x1F)
#define ADC_Channel_16                              ((unsigned char)0x10)
#define ADC_Channel_17                              ((unsigned char)0x11)#define IS_ADC_CHANNEL(CHANNEL) (((CHANNEL) == ADC_Channel_0) || ((CHANNEL) == ADC_Channel_1) || \((CHANNEL) == ADC_Channel_2) || ((CHANNEL) == ADC_Channel_3) || \((CHANNEL) == ADC_Channel_4) || ((CHANNEL) == ADC_Channel_5) || \((CHANNEL) == ADC_Channel_6) || ((CHANNEL) == ADC_Channel_7) || \((CHANNEL) == ADC_Channel_8) || ((CHANNEL) == ADC_Channel_9) || \((CHANNEL) == ADC_Channel_10) || ((CHANNEL) == ADC_Channel_11) || \((CHANNEL) == ADC_Channel_12) || ((CHANNEL) == ADC_Channel_13) || \((CHANNEL) == ADC_Channel_14) || ((CHANNEL) == ADC_Channel_15) || \((CHANNEL) == ADC_Channel_16) || ((CHANNEL) == ADC_Channel_17))/* ADC sampling times --------------------------------------------------------*/
#define ADC_SampleTime_1Cycles                    ((unsigned char)0x00)
#define ADC_SampleTime_2Cycles                    ((unsigned char)0x01)
#define ADC_SampleTime_4Cycles                    ((unsigned char)0x02)
#define ADC_SampleTime_8Cycles                    ((unsigned char)0x03)
#define ADC_SampleTime_16Cycles                   ((unsigned char)0x04)
#define ADC_SampleTime_32Cycles                   ((unsigned char)0x05)
#define ADC_SampleTime_64Cycles                   ((unsigned char)0x06)
#define ADC_SampleTime_128Cycles                  ((unsigned char)0x07)#define IS_ADC_SAMPLE_TIME(TIME) (((TIME) == ADC_SampleTime_1Cycles5)  || \((TIME) == ADC_SampleTime_2Cycles5)  || \((TIME) == ADC_SampleTime_4Cycles5)  || \((TIME) == ADC_SampleTime_8Cycles5)  || \((TIME) == ADC_SampleTime_16Cycles5) || \((TIME) == ADC_SampleTime_32Cycles5) || \((TIME) == ADC_SampleTime_64Cycles5) || \((TIME) == ADC_SampleTime_128Cycles5))/* ADC extrenal trigger sources for injected channels conversion -------------*/
/* For ADC1 and ADC2 */
#define ADC_ExternalTrigInjecConv_T2_TRGO           ((unsigned int)0x00002000)
#define ADC_ExternalTrigInjecConv_T2_CC1            ((unsigned int)0x00003000)
#define ADC_ExternalTrigInjecConv_T3_CC4            ((unsigned int)0x00004000)
#define ADC_ExternalTrigInjecConv_T4_TRGO           ((unsigned int)0x00005000)
#define ADC_ExternalTrigInjecConv_Ext_IT15_TIM8_CC4 ((unsigned int)0x00006000)
/* For ADC1, ADC2 and ADC3 */
#define ADC_ExternalTrigInjecConv_T1_TRGO           ((unsigned int)0x00000000)
#define ADC_ExternalTrigInjecConv_T1_CC4            ((unsigned int)0x00001000)
#define ADC_ExternalTrigInjecConv_None              ((unsigned int)0x00007000)
/* For ADC3 */
#define ADC_ExternalTrigInjecConv_T4_CC3            ((unsigned int)0x00002000)
#define ADC_ExternalTrigInjecConv_T8_CC2            ((unsigned int)0x00003000)
#define ADC_ExternalTrigInjecConv_T8_CC4            ((unsigned int)0x00004000)
#define ADC_ExternalTrigInjecConv_T5_TRGO           ((unsigned int)0x00005000)
#define ADC_ExternalTrigInjecConv_T5_CC4            ((unsigned int)0x00006000)#define IS_ADC_EXT_INJEC_TRIG(INJTRIG) (((INJTRIG) == ADC_ExternalTrigInjecConv_T1_TRGO) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T1_CC4) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T2_TRGO) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T2_CC1) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T3_CC4) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T4_TRGO) || \((INJTRIG) == ADC_ExternalTrigInjecConv_Ext_IT15_TIM8_CC4) || \((INJTRIG) == ADC_ExternalTrigInjecConv_None) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T4_CC3) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T8_CC2) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T8_CC4) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T5_TRGO) || \((INJTRIG) == ADC_ExternalTrigInjecConv_T5_CC4))/* ADC injected channel selection --------------------------------------------*/
#define ADC_InjectedChannel_1                       ((unsigned char)0x14)
#define ADC_InjectedChannel_2                       ((unsigned char)0x18)
#define ADC_InjectedChannel_3                       ((unsigned char)0x1C)
#define ADC_InjectedChannel_4                       ((unsigned char)0x20)#define IS_ADC_INJECTED_CHANNEL(CHANNEL) (((CHANNEL) == ADC_InjectedChannel_1) || \((CHANNEL) == ADC_InjectedChannel_2) || \((CHANNEL) == ADC_InjectedChannel_3) || \((CHANNEL) == ADC_InjectedChannel_4))/* ADC analog watchdog selection ---------------------------------------------*/
#define ADC_AnalogWatchdog_SingleRegEnable         ((unsigned int)0x00800200)
#define ADC_AnalogWatchdog_SingleInjecEnable       ((unsigned int)0x00400200)
#define ADC_AnalogWatchdog_SingleRegOrInjecEnable  ((unsigned int)0x00C00200)
#define ADC_AnalogWatchdog_AllRegEnable            ((unsigned int)0x00800000)
#define ADC_AnalogWatchdog_AllInjecEnable          ((unsigned int)0x00400000)
#define ADC_AnalogWatchdog_AllRegAllInjecEnable    ((unsigned int)0x00C00000)
#define ADC_AnalogWatchdog_None                    ((unsigned int)0x00000000)#define IS_ADC_ANALOG_WATCHDOG(WATCHDOG) (((WATCHDOG) == ADC_AnalogWatchdog_SingleRegEnable) || \((WATCHDOG) == ADC_AnalogWatchdog_SingleInjecEnable) || \((WATCHDOG) == ADC_AnalogWatchdog_SingleRegOrInjecEnable) || \((WATCHDOG) == ADC_AnalogWatchdog_AllRegEnable) || \((WATCHDOG) == ADC_AnalogWatchdog_AllInjecEnable) || \((WATCHDOG) == ADC_AnalogWatchdog_AllRegAllInjecEnable) || \((WATCHDOG) == ADC_AnalogWatchdog_None))/* ADC interrupts definition -------------------------------------------------*/
#define ADC_IT_EOC                                 ((unsigned short)0x0220)
#define ADC_IT_AWD                                 ((unsigned short)0x0140)
#define ADC_IT_JEOC                                ((unsigned short)0x0480)#define IS_ADC_IT(IT) ((((IT) & (unsigned short)0xF81F) == 0x00) && ((IT) != 0x00))
#define IS_ADC_GET_IT(IT) (((IT) == ADC_IT_EOC) || ((IT) == ADC_IT_AWD) || \((IT) == ADC_IT_JEOC))/* ADC flags definition ------------------------------------------------------*/
#define ADC_FLAG_AWD                               ((unsigned char)0x01)
#define ADC_FLAG_EOC                               ((unsigned char)0x02)
#define ADC_FLAG_JEOC                              ((unsigned char)0x04)
#define ADC_FLAG_JSTRT                             ((unsigned char)0x08)
#define ADC_FLAG_STRT                              ((unsigned char)0x10)#define IS_ADC_CLEAR_FLAG(FLAG) ((((FLAG) & (unsigned char)0xE0) == 0x00) && ((FLAG) != 0x00))
#define IS_ADC_GET_FLAG(FLAG) (((FLAG) == ADC_FLAG_AWD) || ((FLAG) == ADC_FLAG_EOC) || \((FLAG) == ADC_FLAG_JEOC) || ((FLAG)== ADC_FLAG_JSTRT) || \((FLAG) == ADC_FLAG_STRT))/* ADC thresholds ------------------------------------------------------------*/
#define IS_ADC_THRESHOLD(THRESHOLD) ((THRESHOLD) <= 0xFFF)/* ADC injected offset -------------------------------------------------------*/
#define IS_ADC_OFFSET(OFFSET) ((OFFSET) <= 0xFFF)/* ADC injected length -------------------------------------------------------*/
#define IS_ADC_INJECTED_LENGTH(LENGTH) (((LENGTH) >= 0x1) && ((LENGTH) <= 0x4))/* ADC injected rank ---------------------------------------------------------*/
#define IS_ADC_INJECTED_RANK(RANK) (((RANK) >= 0x1) && ((RANK) <= 0x4))/* ADC regular length --------------------------------------------------------*/
#define IS_ADC_REGULAR_LENGTH(LENGTH) (((LENGTH) >= 0x1) && ((LENGTH) <= 0x10))/* ADC regular rank ----------------------------------------------------------*/
#define IS_ADC_REGULAR_RANK(RANK) (((RANK) >= 0x1) && ((RANK) <= 0x10))/* ADC regular discontinuous mode number -------------------------------------*/
#define IS_ADC_REGULAR_DISC_NUMBER(NUMBER) (((NUMBER) >= 0x1) && ((NUMBER) <= 0x8))//Loongson Feature
#define RCH0  ADC_Channel_0
#define RCH1  ADC_Channel_1
#define RCH2  ADC_Channel_2
#define RCH3  ADC_Channel_3
#define RCH4  ADC_Channel_4
#define RCH5  ADC_Channel_5
#define RCH6  ADC_Channel_6
#define RCH7  ADC_Channel_7//Loongson Feature
#define JCH0  ADC_Channel_0
#define JCH1  ADC_Channel_1
#define JCH2  ADC_Channel_2
#define JCH3  ADC_Channel_3void adc_init(adc_reg_map* ADCx, adc_init_info* ADC_InitStruct);
void adc_struct_init(adc_init_info* ADC_InitStruct);
void ADC_RegularChannelConfig(adc_reg_map* ADCx, unsigned char ADC_Channel, unsigned char Rank, unsigned char ADC_SampleTime);
void adc_dev_enable(adc_reg_map* ADCx, FunctionalState state);
void adc_software_start_conv_trigger(adc_reg_map* ADCx, FunctionalState state, unsigned char J_channel);
void adc_eoc_check_conv_end(adc_reg_map* ADCx);#endif /* __LOONGSON_2K300_ADC_CORE_H__ */

Kconfig

需要在drivers/iio/adc下的Kconfig加入以下代码

config LS_2K300_ADCtristate "ls2k300 driver"select IIO_BUFFERselect IIO_TRIGGERED_BUFFERhelploongson 2k300 ADC driver

Makefile

需要在drivers/iio/adc下的Makefile加入以下代码

obj-$(CONFIG_LS_2K300_ADC) += loongson-2k300-adc.o loongson-2k300-adc-core.o

loongson_2k0300.dtsi

dtsi文件下加入以下代码

adc: adc@0x1611c000 {compatible = "ls2k300-adc";reg = <0 0x1611c000 0 0x50>;status = "disabled";num-channels = <0>;
};

loongson_2k0300_pai_99.dts

dts设备树下加入adc节点

&adc {status = "okay";
};

.config

在内核根目录下的配置文件加入以下开关

CONFIG_IIO=y
CONFIG_LS_2K300_ADC=y

修改完毕后重新编译内核，将内核部署到开发板/boot目录下，重启开发板发现/sys/bus/iio/devices/iio/device0目录下已经生成了相应的in_voltageX_raw节点

在这里插入图片描述

接口

久久派上集成8路12位ADC采样接口，支持单端采样，也支持差分采样，参考电压Vref为1.8V

PIN	信号定义	备注
1	P3V3	3.3V 电源输出
2	GND0	地线
3	ADC 通道 4	0/4 通道可以独立采样，也可以作为差分采样
4	ADC 通道 0	0/4 通道可以独立采样，也可以作为差分采样
5	ADC 通道 1	1/5 通道可以独立采样，也可以作为差分采样
6	ADC 通道 5	1/5 通道可以独立采样，也可以作为差分采样
7	ADC 通道 2	2/6 通道可以独立采样，也可以作为差分采样
8	ADC 通道 6	2/6 通道可以独立采样，也可以作为差分采样
9	ADC 通道 3	3/7 通道可以独立采样，也可以作为差分采样
10	ADC 通道 7	3/7 通道可以独立采样，也可以作为差分采样

原理图如下，J1针脚处可见ADC并不是按顺序分布的

在这里插入图片描述

测试

以读取ADC0通道为例，测试命令如下（其中raw为ADC原始数据，scale为单位分辨率所占的电压值，两者相乘可得到实际电压值）

raw=$(cat /sys/bus/iio/devices/iio\:device0/in_voltage0_raw)
scale=$(cat /sys/bus/iio/devices/iio\:device0/in_voltage_scale)
echo "vol_raw : $raw,vol_scale:$scale"

使用电位器调节到1.8V左右，和读取的数值较为接近：0.439453125 * 4095 / 1000约等于1.8V

在这里插入图片描述

参考

linux-5.10: linux for loongson2 (gitee.com)

实验目的

驱动移植

loongson-2k300-adc.c

loongson-2k300-adc-core.c

loongson-2k300-adc-core.h

Kconfig

Makefile

loongson_2k0300.dtsi

loongson_2k0300_pai_99.dts

.config

接口

测试

参考

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