芯耀
166
例程代碼路徑：ELF 1開發(fā)板資料包3-例程源碼3-2 驅(qū)動例程源碼9_Regmap-icm20607
下面編寫一個六軸傳感器的驅(qū)動，來了解Regmap子系統(tǒng)的具體使用。
一、修改設(shè)備樹
（一）查看原理圖和引腳復(fù)用表格，確定六軸傳感器連接引腳。
（二）在設(shè)備樹文件arch/arm/boot/dts/imx6ull-elf1-emmc.dts的IOMUX節(jié)點下添加子節(jié)點：
| pinctrl_ecspi1: ecspi1grp {
fsl,pins = < MX6UL_PAD_LCD_DATA20__ECSPI1_SCLK ??????0x10b0 MX6UL_PAD_LCD_DATA21__GPIO3_IO26 ????????0x10b0 MX6UL_PAD_LCD_DATA22__ECSPI1_MOSI ??????0x10b0 MX6UL_PAD_LCD_DATA23__ECSPI1_MISO ??????0x10b0 >; }; |
添加后效果如下：
在arch/arm/boot/dts/imx6ull-elf1-emmc.dts文件中搜索引腳PAD NAME，在&iomux的子節(jié)點pinctrl_lcdif_dat節(jié)點下搜索到了這幾個引腳的復(fù)用，我們需要將這些注釋掉：
（三）添加設(shè)備節(jié)點
在arch/arm/boot/dts/imx6ull.dtsi中已經(jīng)存在了spi接口的相關(guān)節(jié)點ecspi1-ecspi4，我們只需要在arch/arm/boot/dts/imx6ull-elf1-emmc.dts文件中引用相關(guān)節(jié)點，并在該節(jié)點下添加子節(jié)點spidevicm：
| &ecspi1 {
pinctrl-names = "default"; pinctrl-0 = <&pinctrl_ecspi1>; fsl,spi-num-chipselects = <1>; cs-gpios = <&gpio3 26 GPIO_ACTIVE_LOW>; status = "okay"; spidevicm: icm20607@0 { compatible = "icm20607"; spi-max-frequency = <8000000>; reg = <0>; }; }; |
添加后的效果如下：
（四）重新編譯設(shè)備樹，用7.9.4.2節(jié)編譯好的內(nèi)核即可：
| . /opt/fsl-imx-x11/4.1.15-2.0.0/environment-setup-cortexa7hf-neon-poky-linux-gnueabi
elf@ubuntu:~/work/linux-imx-imx_4.1.15_2.0.0_ga$ make dtbs |
編譯生成的設(shè)備樹文件為imx6ull-elf1-emmc.dtb，參考《01-0 ELF1、ELF1S開發(fā)板_快速啟動手冊_V1》4.4節(jié)單獨更新設(shè)備樹。
二、編寫icm20607.c驅(qū)動
（一）在驅(qū)動中要操作很多芯片相關(guān)的寄存器，所以需要先新建一個icm20607.h的頭文件，用來定義相關(guān)寄存器值。
| #ifndef ICM20607_H
#define ICM20607_H /*************************************************************** 文件名 : icm20607.h 描述 : ICM20607寄存器地址描述頭文件 ***************************************************************/ #define ICM20608G_ID 0XAF /* ID值 */ #define ICM20608D_ID 0XAE /* ID值 */ #define ICM20607_ID 0X05 /* ICM20607寄存器 *復(fù)位后所有寄存器地址都為0，除了 *Register 107(0x41) Power Management 1 *Register 117(0x05) WHO_AM_I *Register 26(0x80) CONFIG */ /* 陀螺儀和加速度自測(出產(chǎn)時設(shè)置，用于與用戶的自檢輸出值比較） */ /* ICM20607 SELF TEST GYRO Modify 0x ->5x */ #define ICM20_SELF_TEST_X_GYRO 0x50 #define ICM20_SELF_TEST_Y_GYRO 0x51 #define ICM20_SELF_TEST_Z_GYRO 0x52 #define ICM20_SELF_TEST_X_ACCEL 0x0D #define ICM20_SELF_TEST_Y_ACCEL 0x0E #define ICM20_SELF_TEST_Z_ACCEL 0x0F /* 陀螺儀靜態(tài)偏移 */ #define ICM20_XG_OFFS_USRH 0x13 #define ICM20_XG_OFFS_USRL 0x14 #define ICM20_YG_OFFS_USRH 0x15 #define ICM20_YG_OFFS_USRL 0x16 #define ICM20_ZG_OFFS_USRH 0x17 #define ICM20_ZG_OFFS_USRL 0x18 #define ICM20_SMPLRT_DIV 0x19 #define ICM20_CONFIG 0x1A #define ICM20_GYRO_CONFIG 0x1B #define ICM20_ACCEL_CONFIG 0x1C #define ICM20_ACCEL_CONFIG2 0x1D #define ICM20_LP_MODE_CFG 0x1E #define ICM20_ACCEL_WOM_THR 0x1F #define ICM20_FIFO_EN 0x23 #define ICM20_FSYNC_INT 0x36 #define ICM20_INT_PIN_CFG 0x37 #define ICM20_INT_ENABLE 0x38 #define ICM20_INT_STATUS 0x3A /* 加速度輸出 */ #define ICM20_ACCEL_XOUT_H 0x3B #define ICM20_ACCEL_XOUT_L 0x3C #define ICM20_ACCEL_YOUT_H 0x3D #define ICM20_ACCEL_YOUT_L 0x3E #define ICM20_ACCEL_ZOUT_H 0x3F #define ICM20_ACCEL_ZOUT_L 0x40 /* 溫度輸出 */ #define ICM20_TEMP_OUT_H 0x41 #define ICM20_TEMP_OUT_L 0x42 /* 陀螺儀輸出 */ #define ICM20_GYRO_XOUT_H 0x43 #define ICM20_GYRO_XOUT_L 0x44 #define ICM20_GYRO_YOUT_H 0x45 #define ICM20_GYRO_YOUT_L 0x46 #define ICM20_GYRO_ZOUT_H 0x47 #define ICM20_GYRO_ZOUT_L 0x48 #define ICM20_SIGNAL_PATH_RESET 0x68 #define ICM20_ACCEL_INTEL_CTRL 0x69 #define ICM20_USER_CTRL 0x6A #define ICM20_PWR_MGMT_1 0x6B #define ICM20_PWR_MGMT_2 0x6C #define ICM20_FIFO_COUNTH 0x72 #define ICM20_FIFO_COUNTL 0x73 #define ICM20_FIFO_R_W 0x74 #define ICM20_WHO_AM_I 0x75 /* 加速度靜態(tài)偏移 */ #define ICM20_XA_OFFSET_H 0x77 #define ICM20_XA_OFFSET_L 0x78 #define ICM20_YA_OFFSET_H 0x7A #define ICM20_YA_OFFSET_L 0x7B #define ICM20_ZA_OFFSET_H 0x7D #define ICM20_ZA_OFFSET_L 0x7E #endif |
（二）icm20607.c文件編寫
（1）頭文件引用
| #include <linux/module.h>
#include <linux/init.h> #include <linux/fs.h> ??????????// 包含文件系統(tǒng)相關(guān)函數(shù)的頭文件 #include <linux/uaccess.h> ?????// 包含用戶空間數(shù)據(jù)訪問函數(shù)的頭文件 #include <linux/cdev.h> ????????//包含字符設(shè)備頭文件 #include <linux/device.h> #include <linux/delay.h> #include <linux/spi/spi.h> #include <linux/regmap.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_gpio.h> #include "icm20607.h" |
（2）創(chuàng)建相關(guān)宏定義和變量
| #define ICM20607_REG_WHOAMI ?????0x75
#define ICM20607_WHOAMI_VALUE ???0xAF #define DEVICE_NAME "icm20607" ?// 設(shè)備名稱 static dev_t dev_num; ??//分配的設(shè)備號 int major; ?//主設(shè)備號 int minor; ?//次設(shè)備號 struct icm20607_dev { struct spi_device *spi_dev; /* spi設(shè)備 */ dev_t dev_num; /* 設(shè)備號 ?*/ struct cdev cdev; /* cdev */ struct class *class; /* 類 */ struct device *device; /* 設(shè)備 ?*/ struct device_node *nd; /* 設(shè)備節(jié)點 */ int cs_gpio; /* 片選所使用的GPIO編號 */ signed int gyro_x_adc; /* 陀螺儀X軸原始值 ?*/ signed int gyro_y_adc; /* 陀螺儀Y軸原始值 */ signed int gyro_z_adc; /* 陀螺儀Z軸原始值 */ signed int accel_x_adc; /* 加速度計X軸原始值 */ signed int accel_y_adc; /* 加速度計Y軸原始值 */ signed int accel_z_adc; /* 加速度計Z軸原始值 */ signed int temp_adc; /* 溫度原始值 */ struct regmap *spi_regmap; /* regmap */ struct regmap_config regmap_config; }; |
（3）驅(qū)動模塊的入口和出口
| module_init(icm20607_init);
module_exit(icm20607_exit); |
（4）icm20607_init和icm20607_exit實現(xiàn)
| static int __init icm20607_init(void)
{ int ret; ret = spi_register_driver(&icm20607_driver); if (ret < 0) { pr_err("Failed to register ICM20607 driver: %dn", ret); return ret; } pr_info("ICM20607 SPI device driver loadedn"); return 0; } static void __exit icm20607_exit(void) { spi_unregister_driver(&icm20607_driver); pr_info("ICM20607 SPI device driver unloadedn"); } |
在入口函數(shù)中調(diào)用了spi_register_driver函數(shù)，來注冊SPI總線驅(qū)動程序。在出口函數(shù)中調(diào)用了spi_unregister_driver函數(shù)，來注銷驅(qū)動程序。
spi_register_driver函數(shù)原型如下：
| int spi_register_driver(struct spi_driver *drv); |
該函數(shù)接受一個指向struct spi_driver結(jié)構(gòu)體的指針作為參數(shù)，并返回一個整數(shù)值，表示注冊是否成功。struct spi_driver結(jié)構(gòu)體定義了SPI總線驅(qū)動程序的屬性和回調(diào)函數(shù)。
以下是struct spi_driver結(jié)構(gòu)體的常見成員：
driver：struct device_driver類型的成員，描述了驅(qū)動程序的基本信息，如名稱、總線類型等。
probe：指向驅(qū)動程序的探測函數(shù)的指針。探測函數(shù)在與設(shè)備匹配時被調(diào)用，用于初始化設(shè)備并注冊相關(guān)資源。
remove：指向驅(qū)動程序的移除函數(shù)的指針。移除函數(shù)在設(shè)備被卸載時被調(diào)用，用于清理和釋放相關(guān)資源。
id_table：指向struct spi_device_id數(shù)組的指針，用于匹配驅(qū)動程序和設(shè)備之間的關(guān)聯(lián)關(guān)系。
probe_new：指向新版的探測函數(shù)的指針。新版探測函數(shù)支持更多功能，并可以替代舊版的probe函數(shù)。
remove_new：指向新版的移除函數(shù)的指針。新版移除函數(shù)支持更多功能，并可以替代舊版的remove函數(shù)。
通過調(diào)用spi_register_driver函數(shù)并傳入正確配置的struct spi_driver結(jié)構(gòu)體，可以將SPI總線驅(qū)動程序注冊到Linux內(nèi)核，使其能夠接收和處理SPI設(shè)備的相關(guān)操作。
（5）spi_driver類型結(jié)構(gòu)體定義
| static struct spi_driver icm20607_driver = {
.driver = { .name = "icm20607", .owner = THIS_MODULE, .of_match_table = icm20607_of__match, }, .probe = icm20607_probe, .remove = icm20607_remove, }; |
（6）icm20607_of__match實現(xiàn)，用來與設(shè)備樹中的compatible匹配
| static const struct of_device_id icm20608_of_match[] = {
{ .compatible = "icm20607" }, { /* Sentinel */ } }; |
（7）remove函數(shù)實現(xiàn)，執(zhí)行icm20607設(shè)備的清理操作
| static int icm20607_remove(struct spi_device *spi)
{ struct icm20607_dev *icm20607dev = spi_get_drvdata(spi); // 在此處執(zhí)行 ICM20607 設(shè)備的清理操作 //刪除cdev cdev_del(&icm20607dev->cdev); //注銷設(shè)備號 unregister_chrdev_region(icm20607dev->dev_num, 1); //注銷設(shè)備 device_destroy(icm20607dev->class, icm20608dev->dev_num); //注銷類 class_destroy(icm20607dev->class); //刪除regmap regmap_exit(icm20607dev->spi_regmap); pr_info("ICM20607 SPI device removed successfullyn"); return 0; } |
（8）probe函數(shù)實現(xiàn)，此處簡略描述regmap注冊的過程：
| static int icm20607_probe(struct spi_device *spi)
{ int ret; unsigned int whoami; struct icm20607_dev *icm20607dev; //分配icm20607dev對象的空間 icm20607dev = devm_kzalloc(&spi->dev, sizeof(*icm20607dev), GFP_KERNEL); if(!icm20607dev) return -ENOMEM; // 創(chuàng)建 ICM20607 設(shè)備的 regmap icm20608dev->spi_regmap = regmap_init_spi(spi, &spi_regmap_config); if (IS_ERR(icm20607dev->spi_regmap)) { dev_err(&spi->dev, "Failed to initialize regmap: %ldn", PTR_ERR(icm20607dev->spi_regmap)); return PTR_ERR(icm20607dev->spi_regmap); } ...... /*初始化spi_device */ icm20607dev->spi_dev = spi; spi->mode = SPI_MODE_0; spi_setup(spi); /* 初始化ICM20607內(nèi)部寄存器 */ icm20607_reginit(icm20607dev); /* 保存icm20607dev結(jié)構(gòu)體 */ spi_set_drvdata(spi, icm20607dev); pr_info("ICM20607 SPI device probed successfullyn"); return 0; } |
probe函數(shù)中首先使用devm_kzalloc函數(shù)分配了icm20607dev的結(jié)構(gòu)體空間，然后使用regmap_init_spi函數(shù)創(chuàng)建regmap實例，再進行spi控制器的初始化和配置，最后對ICM20607的內(nèi)部寄存器進行配置。
其中regmap_init_spi函數(shù)中傳入了“&spi_regmap_config”參數(shù)，前邊有提到這個是用來配置regmap對象的，下邊我們看這個參數(shù)是如何定義的。
（9）spi_regmap_config的定義
| static const struct regmap_config spi_regmap_config = {
.reg_bits = 8, .val_bits = 8, .read_flag_mask = 0x80, .reg_read = icm20607_spi_read, .reg_write = icm20607_spi_write, .max_register = ICM20607_REG_WHOAMI, }; |
可以看到這其中規(guī)定了寄存器地址的位數(shù)，存儲寄存器的位數(shù)，讀寄存器掩碼，讀寄存器函數(shù)，寫寄存器函數(shù)，最大寄存器地址。
（10）讀寫寄存器函數(shù)實現(xiàn)
| static int icm20607_spi_read(struct icm20608_dev *dev, unsigned int reg, unsigned int *val)
{ return regmap_read(dev->spi_regmap, reg, val); } static int icm20607_spi_write(struct icm20608_dev *dev, unsigned int reg, unsigned int val) { return regmap_write(dev->spi_regmap, reg, val); } |
可以看出讀寫函數(shù)非常簡單明了，直接使用regmap_read和regmap_write函數(shù)即可。
①regmap_read函數(shù)原型如下：
| int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val); |
該函數(shù)用于從給定的寄存器地址(reg)讀取數(shù)據(jù)，并將讀取的值存儲在val指向的變量中。map參數(shù)是一個指向struct regmap的指針，表示寄存器映射對象。返回值為0表示讀取成功，否則表示讀取失敗。
②regmap_write函數(shù)原型如下：
| int regmap_write(struct regmap *map, unsigned int reg, unsigned int val); |
該函數(shù)用于向給定的寄存器地址(reg)寫入數(shù)據(jù)(val)。map參數(shù)是一個指向struct regmap的指針，表示寄存器映射對象。返回值為0表示寫入成功，否則表示寫入失敗。
三、完整驅(qū)動icm20607.c示例源碼
| #include <linux/module.h>
#include <linux/init.h> #include <linux/fs.h> ??????????// 包含文件系統(tǒng)相關(guān)函數(shù)的頭文件 #include <linux/uaccess.h> ?????// 包含用戶空間數(shù)據(jù)訪問函數(shù)的頭文件 #include <linux/cdev.h> ????????//包含字符設(shè)備頭文件 #include <linux/device.h> #include <linux/delay.h> #include <linux/spi/spi.h> #include <linux/regmap.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_gpio.h> #include "icm20607.h" #define ICM20607_REG_WHOAMI ?????0x75 #define ICM20607_WHOAMI_VALUE ???0xAF #define DEVICE_NAME "icm20607" ?// 設(shè)備名稱 static dev_t dev_num; ??//分配的設(shè)備號 int major; ?//主設(shè)備號 int minor; ?//次設(shè)備號 struct icm20607_dev { struct spi_device *spi_dev; ????/* spi設(shè)備 */ dev_t dev_num; ?????????????????/* 設(shè)備號*/ struct cdev cdev; ??????????????/* cdev */ struct class *class; ???????????/* 類*/ struct device *device; ?????????/* 設(shè)備 */ struct device_node ?????*nd; ???/* 設(shè)備節(jié)點 */ int cs_gpio; ???????????????????????????/* 片選所使用的GPIO編號 */ signed int gyro_x_adc; ?????????/* 陀螺儀X軸原始值*/ signed int gyro_y_adc; ?????????/* 陀螺儀Y軸原始值*/ signed int gyro_z_adc; ?????????/* 陀螺儀Z軸原始值*/ signed int accel_x_adc; ????????/* 加速度計X軸原始值*/ signed int accel_y_adc; ????????/* 加速度計Y軸原始值*/ signed int accel_z_adc; ????????/* 加速度計Z軸原始值*/ signed int temp_adc; ???????????/* 溫度原始值*/ struct regmap *spi_regmap; ?????????????/* regmap */ struct regmap_config regmap_config; }; void icm20607_readdata(struct icm20607_dev *dev) { u8 ret; unsigned char data[14]; ret = regmap_bulk_read(dev->spi_regmap, ICM20_ACCEL_XOUT_H, data, 14);/*讀多個寄存器的值*/ dev->accel_x_adc = (signed short)((data[0] << 8) | data[1]); dev->accel_y_adc = (signed short)((data[2] << 8) | data[3]); dev->accel_z_adc = (signed short)((data[4] << 8) | data[5]); dev->temp_adc ???= (signed short)((data[6] << 8) | data[7]); dev->gyro_x_adc ?= (signed short)((data[8] << 8) | data[9]); dev->gyro_y_adc ?= (signed short)((data[10] << 8) | data[11]); dev->gyro_z_adc ?= (signed short)((data[12] << 8) | data[13]); } static int icm20607_spi_read(struct icm20607_dev *dev, unsigned int reg, unsigned int *val) { return regmap_read(dev->spi_regmap, reg, val); } static int icm20607_spi_write(struct icm20607_dev *dev, unsigned int reg, unsigned int val) { return regmap_write(dev->spi_regmap, reg, val); } static const struct regmap_config spi_regmap_config = { .reg_bits = 8, .val_bits = 8, .read_flag_mask = 0x80, .reg_read = icm20607_spi_read, .reg_write = icm20607_spi_write, .max_register = ICM20607_REG_WHOAMI, }; static int device_open(struct inode *inode, struct file *file) { // 在這里處理設(shè)備打開的操作 printk(KERN_INFO "This is device_open.n"); return 0; } static int device_release(struct inode *inode, struct file *file) { // 在這里處理設(shè)備關(guān)閉的操作 printk(KERN_INFO "This is device_release.n"); return 0; } static ssize_t device_read(struct file *file, char __user *buffer, size_t length, loff_t *offset) { signed int data[7]; long err = 0; struct cdev *cdev = file->f_path.dentry->d_inode->i_cdev; struct icm20607_dev *dev = container_of(cdev, struct icm20607_dev, cdev); icm20607_readdata(dev); data[0] = dev->gyro_x_adc; data[1] = dev->gyro_y_adc; data[2] = dev->gyro_z_adc; data[3] = dev->accel_x_adc; data[4] = dev->accel_y_adc; data[5] = dev->accel_z_adc; data[6] = dev->temp_adc; err = copy_to_user(buffer, data, sizeof(data)); return 0; } static ssize_t device_write(struct file *file, const char __user *buffer, size_t length, loff_t *offset) { // 在這里處理設(shè)備寫入的操作 printk(KERN_INFO "This is device_write.n"); return 0; } void icm20607_reginit(struct icm20607_dev *dev) { u8 value = 0; icm20607_spi_write(dev, ICM20_PWR_MGMT_1, 0x80); mdelay(50); icm20607_spi_write(dev, ICM20_PWR_MGMT_1, 0x01); mdelay(50); icm20607_spi_read(dev, ICM20_WHO_AM_I,&value); printk("ICM20607 ID = %#Xrn", value); icm20607_spi_write(dev, ICM20_SMPLRT_DIV, 0x00); ?????/* 輸出速率是內(nèi)部采樣率*/ icm20607_spi_write(dev, ICM20_GYRO_CONFIG, 0x18); ?????/* 陀螺儀±2000dps量程 */ icm20607_spi_write(dev, ICM20_ACCEL_CONFIG, 0x18); ????/* 加速度計±16G量程*/ icm20607_spi_write(dev, ICM20_CONFIG, 0x04); ???????????/* 陀螺儀低通濾波BW=20Hz */ icm20607_spi_write(dev, ICM20_ACCEL_CONFIG2, 0x04); /* 加速度計低通濾波BW=21.2Hz */ icm20607_spi_write(dev, ICM20_PWR_MGMT_2, 0x00); ???????/* 打開加速度計和陀螺儀所有軸*/ icm20607_spi_write(dev, ICM20_LP_MODE_CFG, 0x00); ??????/* 關(guān)閉低功耗*/ icm20607_spi_write(dev, ICM20_FIFO_EN, 0x00); ??????????/* 關(guān)閉FIFO */ } static struct file_operations fops = { .owner = THIS_MODULE, .open = device_open, .release = device_release, .read = device_read, .write = device_write, }; static int icm20607_probe(struct spi_device *spi) { int ret; unsigned int whoami; struct icm20607_dev *icm20607dev; /* 分配icm20607dev對象的空間 */ icm20607dev = devm_kzalloc(&spi->dev, sizeof(*icm20607dev), GFP_KERNEL); if(!icm20607dev) return -ENOMEM; // 創(chuàng)建 ICM20607 設(shè)備的 regmap icm20607dev->spi_regmap = regmap_init_spi(spi, &spi_regmap_config); if (IS_ERR(icm20607dev->spi_regmap)) { dev_err(&spi->dev, "Failed to initialize regmap: %ldn", PTR_ERR(icm20607dev->spi_regmap)); return PTR_ERR(icm20607dev->spi_regmap); } // 注冊字符設(shè)備驅(qū)動程序 ret = alloc_chrdev_region(&icm20607dev->dev_num,0,1,DEVICE_NAME); if (ret < 0) { printk(KERN_ALERT "Failed to allocate device number: %dn", ret); return ret; } major=MAJOR(icm20607dev->dev_num); minor=MINOR(icm20607dev->dev_num); printk(KERN_INFO "major number: %dn",major); printk(KERN_INFO "minor number: %dn",minor); icm20607dev->cdev.owner = THIS_MODULE; cdev_init(&icm20607dev->cdev,&fops); cdev_add(&icm20607dev->cdev,icm20607dev->dev_num,1); // 創(chuàng)建設(shè)備類 icm20607dev->class = class_create(THIS_MODULE, DEVICE_NAME); if (IS_ERR(icm20607dev->class)) { pr_err("Failed to create classn"); return PTR_ERR(icm20607dev->class); } // 創(chuàng)建設(shè)備節(jié)點并關(guān)聯(lián)到設(shè)備類 icm20607dev->device = device_create(icm20607dev->class, NULL, MKDEV(major, minor), NULL, DEVICE_NAME); if (IS_ERR(icm20607dev->device)) { pr_err("Failed to create devicen"); class_destroy(icm20607dev->class); return PTR_ERR(icm20607dev->device); } /*初始化spi_device */ icm20607dev->spi_dev = spi; spi->mode = SPI_MODE_0; spi_setup(spi); /* 初始化ICM20607內(nèi)部寄存器 */ icm20607_reginit(icm20607dev); /* 保存icm20607dev結(jié)構(gòu)體 */ spi_set_drvdata(spi, icm20607dev); pr_info("ICM20607 SPI device probed successfullyn"); return 0; } static int icm20607_remove(struct spi_device *spi) { struct icm20607_dev *icm20607dev = spi_get_drvdata(spi); // 在此處執(zhí)行 ICM20607 設(shè)備的清理操作 //刪除cdev cdev_del(&icm20607dev->cdev); //注銷設(shè)備號 unregister_chrdev_region(icm20607dev->dev_num, 1); //注銷設(shè)備 device_destroy(icm20607dev->class, icm20607dev->dev_num); //注銷類 class_destroy(icm20607dev->class); //刪除regmap regmap_exit(icm20607dev->spi_regmap); pr_info("ICM20607 SPI device removed successfullyn"); return 0; } static const struct of_device_id icm20607_of__match[] = { { .compatible = "icm20607", }, {}, }; static struct spi_driver icm20607_driver = { .driver = { .name = "icm20607", .owner = THIS_MODULE, .of_match_table = icm20607_of__match, }, .probe = icm20607_probe, .remove = icm20607_remove, }; static int __init icm20607_init(void) { int ret; ret = spi_register_driver(&icm20607_driver); if (ret < 0) { pr_err("Failed to register ICM20607 driver: %dn", ret); return ret; } pr_info("ICM20607 SPI device driver loadedn"); return 0; } static void __exit icm20607_exit(void) { spi_unregister_driver(&icm20607_driver); pr_info("ICM20607 SPI device driver unloadedn"); } module_init(icm20607_init); module_exit(icm20607_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Your Name"); MODULE_DESCRIPTION("ICM20607 SPI device driver"); |
四、編譯
Makefile修改如下：
| . /opt/fsl-imx-x11/4.1.15-2.0.0/environment-setup-cortexa7hf-neon-poky-linux-gnueabi
elf@ubuntu:~/work/test/09_Regmap子系統(tǒng)-icm20607/icm20607$ make |
將編譯生成的icm20607.ko模塊拷貝到開發(fā)板。
五、編寫測試源碼icm20607_app.c
測試源碼中循環(huán)讀取驅(qū)動傳到用戶空間的數(shù)據(jù)：
| #include "stdio.h"
#include "unistd.h" #include "sys/types.h" #include "sys/stat.h" #include "sys/ioctl.h" #include "fcntl.h" #include "stdlib.h" #include "string.h" #include <poll.h> #include <sys/select.h> #include <sys/time.h> #include <signal.h> #include <fcntl.h> #define ICM20607_DEV "/dev/icm20607" int main(int argc, char *argv[]) { int fd; signed int databuf[7]; unsigned char data[14]; signed int gyro_x_adc, gyro_y_adc, gyro_z_adc; signed int accel_x_adc, accel_y_adc, accel_z_adc; signed int temp_adc; float gyro_x_act, gyro_y_act, gyro_z_act; float accel_x_act, accel_y_act, accel_z_act; float temp_act; int ret = 0; fd = open(ICM20607_DEV, O_RDWR); if(fd < 0) { printf("can't open file %srn", ICM20607_DEV); return -1; } while (1) { ret = read(fd, databuf, sizeof(databuf)); if(ret == 0) { /*讀取出原始值 */ gyro_x_adc = databuf[0]; gyro_y_adc = databuf[1]; gyro_z_adc = databuf[2]; accel_x_adc = databuf[3]; accel_y_adc = databuf[4]; accel_z_adc = databuf[5]; temp_adc = databuf[6]; /* 轉(zhuǎn)換為實際值 */ gyro_x_act = (float)(gyro_x_adc) ?/ 16.4; gyro_y_act = (float)(gyro_y_adc) ?/ 16.4; gyro_z_act = (float)(gyro_z_adc) ?/ 16.4; accel_x_act = (float)(accel_x_adc) / 2048; accel_y_act = (float)(accel_y_adc) / 2048; accel_z_act = (float)(accel_z_adc) / 2048; temp_act = ((float)(temp_adc) - 25 ) / 326.8 + 25; printf("rn"); printf("raw value:rn"); printf("gx = %d, gy = %d, gz = %drn", gyro_x_adc, gyro_y_adc, gyro_z_adc); printf("ax = %d, ay = %d, az = %drn", accel_x_adc, accel_y_adc, accel_z_adc); printf("temp = %drn", temp_adc); printf("rn"); printf("act value:rn"); printf("act gx = %.2f度/S, act gy = %.2f度/S, act gz = %.2f度/Srn", gyro_x_act, gyro_y_act, gyro_z_act); printf("act ax = %.2fg, act ay = %.2fg, act az = %.2fgrn", accel_x_act, accel_y_act, accel_z_act); printf("act temp = %.2f攝氏度rn", temp_act); } usleep(100000); /*100ms */ } close(fd); return 0; } |
六、編譯應(yīng)用
| . /opt/fsl-imx-x11/4.1.15-2.0.0/environment-setup-cortexa7hf-neon-poky-linux-gnueabi
elf@ubuntu:~/work/test/09_Regmap子系統(tǒng)-icm20607/icm20607_app$ $CC icm20607_app.c -o icm20607_app |
將編譯好的測試應(yīng)用拷貝到開發(fā)板。
七、測試
| root@ELF1:~#:~#?insmod elf-icm20607.ko
major number: 249 minor number: 0 ICM20607 ID = 0X0 ICM20607 SPI device probed successfully ICM20607 SPI device driver loaded root@ELF1:~#:~# ./icm20607_app This is device_open. raw value: gx = 0, gy = 0, gz = 0 ax = 0, ay = 0, az = 0 temp = 0 act value: act gx = 0.00度/S, act gy = 0.00度/S, act gz = 0.00度/S act ax = 0.00g, act ay = 0.00g, act az = 0.00g act temp = 24.92攝氏度 |
可以看到測試app將六軸傳感器的原始值和轉(zhuǎn)換后的值打印了出來。
