高通msm8916 gpio笔记（基于设备树）
1.通用GPIO控制函数：
gpio_set_value（port_num,0/1） 一般只是在这个GPIO口的寄存器上写上某个值，至于这个端口是否设置为输出，它就管不了！而gpio_direction_output （port_num,0/1)，在某个GPIO口写上某个值之后，还会把这个端口设置为输出模式。首先要调用gpio_direction_output（），以后要设置高低电平时，直接使用gpio_set_value（）就可以了
2.http://wenku.baidu.com/link?url=5ry8VUdQA7-vhasbcfWwfOOTOteFvZCHxWVqAnix3z7kd7TVK4VRPHv22M2C17MAoSdd25mGYCI2qAhs9gwC-TZ1sCVpF24MTBzr8ET3AkGstruct
pinctrl * evm_pinctrl_get(struct device *dev);根据设备获取pin操作句柄，所以的pin操作必须基于此pinctrl句柄。与pinctrl_get接口功能完全一样，只是devm_pinctrl_get会将申请的pinctrl句柄做记账，绑定到设备句柄信息中。
改写后：设备树：msm8916-pinctrl.dtsi
gpio_cameral_flash {
compatible = "qcom,gpio_cameral_flash";
qcom,gpio_cameral_flash = <&msm_gpio 105 0>;
};
驱动：leds-cameral-flash.c
//#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
int gpio_ldo_pin = -1;
int gpio_flag = -1;
static struct class *gpio_cameral_flash_class = NULL;
static struct device *gpio_cameral_flash_dev = NULL;
#define CTL_POWER_ON "1"
#define CTL_POWER_OFF "0"
//cat
static ssize_t gpio_105_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
printk("%s\n", __func__);
sprintf(buf, "gpio_105 is %d\n", gpio_flag);
return strlen(buf);
}
//echo
static ssize_t gpio_105_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
if(!strncmp(buf, CTL_POWER_ON, strlen(CTL_POWER_ON))) {
printk("%s: to enable gpio_105\n", __func__);
gpio_set_value(gpio_ldo_pin, 1);
gpio_flag = 1;
} else if(!strncmp(buf, CTL_POWER_OFF, strlen(CTL_POWER_OFF))) {
printk("%s: to disable gpio_105\n", __func__);
gpio_set_value(gpio_ldo_pin, 0);
gpio_flag = 0;
}
return count;
}
static struct device_attribute gpio_105_dev_attr = { // /sys/class/gpio_cameral_flash下生成gpio_105设备节点
.attr = {
.name = "gpio_105",
.mode = S_IRWXU|S_IRWXG|S_IRWXO, //节点读写权限设置
},
.show = gpio_105_show, //节点读方法
.store = gpio_105_store, //节点写方法
};
static int gpio_cameral_flash_probe(struct platform_device *pdev)
{
int ret = 0;
printk("qcom enter gpio_cameral_flash_probe \n");
gpio_ldo_pin = of_get_named_gpio(pdev->dev.of_node, "qcom,gpio_cameral_flash", 0);
if (gpio_ldo_pin < 0)
printk("xcz gpio_ldo_pin is not available \n");
ret = gpio_request(gpio_ldo_pin, "gpio_cameral_flash");//取名
if(0 != ret) {
printk("qcom gpio request %d failed.", gpio_ldo_pin);
goto fail1;
}
gpio_direction_output(gpio_ldo_pin, 0);
gpio_set_value(gpio_ldo_pin, 0);
gpio_flag = 0;
gpio_cameral_flash_class = class_create(THIS_MODULE, "gpio_cameral_flash");
if(IS_ERR(gpio_cameral_flash_class))
{
ret = PTR_ERR(gpio_cameral_flash_class);
printk("Failed to create class.\n");
return ret;
}
gpio_cameral_flash_dev = device_create(gpio_cameral_flash_class, NULL, 0, NULL, "gpio_gpio_105");//取名
if (IS_ERR(gpio_cameral_flash_dev))
{
ret = PTR_ERR(gpio_cameral_flash_class);
printk("Failed to create device(gpio_cameral_flash_dev)!\n");
return ret;
}
ret = device_create_file(gpio_cameral_flash_dev, &gpio_105_dev_attr);
if(ret)
{
pr_err("%s: gpio_105 creat sysfs failed\n",__func__);
return ret;
}
printk("xcz enter gpio_cameral_flash_probe, ok \n");
fail1:
return ret;
}
//硬件卸载时调用
static int gpio_cameral_flash_remove(struct platform_device *pdev)
{
device_destroy(gpio_cameral_flash_class, 0);
class_destroy(gpio_cameral_flash_class);
device_remove_file(gpio_cameral_flash_dev, &gpio_105_dev_attr);
return 0;
}
static int gpio_cameral_flash_suspend(struct platform_device *pdev,pm_message_t state)
{
return 0;
}
static int gpio_cameral_flash_resume(struct platform_device *pdev)
{
return 0;
}
static struct of_device_id gpio_cameral_flash_dt_match[] = {
{ .compatible = "qcom,gpio_cameral_flash",},
{ },
};
MODULE_DEVICE_TABLE(of, gpio_cameral_flash_dt_match);
static struct platform_driver gpio_flash_driver = { // /sys/class总线下生成设备节点gpio_cameral_flash
.driver = {
.name = "gpio_cameral_flash",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(gpio_cameral_flash_dt_match),
},
.probe = gpio_cameral_flash_probe,
.remove = gpio_cameral_flash_remove,
.suspend = gpio_cameral_flash_suspend,
.resume = gpio_cameral_flash_resume,
};
static __init int gpio_flash_init(void)
{
return platform_driver_register(&gpio_flash_driver);
}
static void __exit gpio_flash_exit(void)
{
platform_driver_unregister(&gpio_flash_driver);
}
module_init(gpio_flash_init);
module_exit(gpio_flash_exit);
MODULE_AUTHOR("GPIO_CAMERAL_FLASH, Inc.");
MODULE_DESCRIPTION("QCOM GPIO_CAMERAL_FLASH");
MODULE_LICENSE("GPL");
来源于：
设备树：msm8916-pinctrl.dtsi
gpio_ldo_power {
compatible = "xcz,gpio_ldo_power";
qcom,gpio_ldo_pin = <&msm_gpio 20 0>;
};
驱动：leds-cameral-flash.c
//#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
int gpio_ldo_pin = -1;
int gpio_flag = -1;
static struct class *gpio_ldo_power_class = NULL;
static struct device *gpio_ldo_power_dev = NULL;
#define CTL_POWER_ON "1"
#define CTL_POWER_OFF "0"
//cat
static ssize_t gpio_22_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
printk("%s\n", __func__);
sprintf(buf, "gpio_22 is %d\n", gpio_flag);
return strlen(buf);
}
//echo
static ssize_t gpio_22_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
if(!strncmp(buf, CTL_POWER_ON, strlen(CTL_POWER_ON))) {
printk("%s: to enable gpio_22\n", __func__);
gpio_set_value(gpio_ldo_pin, 1);
gpio_flag = 1;
} else if(!strncmp(buf, CTL_POWER_OFF, strlen(CTL_POWER_OFF))) {
printk("%s: to disable gpio_22\n", __func__);
gpio_set_value(gpio_ldo_pin, 0);
gpio_flag = 0;
}
return count;
}
static struct device_attribute gpio_22_dev_attr = {
.attr = {
.name = "gpio_22",
.mode = S_IRWXU|S_IRWXG|S_IRWXO,
},
.show = gpio_22_show,
.store = gpio_22_store,
};
static int gpio_ldo_power_probe(struct platform_device *pdev)
{
int ret = 0;
printk("xcz enter gpio_ldo_power_probe \n");
gpio_ldo_pin = of_get_named_gpio(pdev->dev.of_node, "qcom,gpio_ldo_pin", 0);
if (gpio_ldo_pin < 0)
printk("xcz gpio_ldo_pin is not available \n");
ret = gpio_request(gpio_ldo_pin, "gpio_ldo_pin");
if(0 != ret) {
printk("xcz gpio request %d failed.", gpio_ldo_pin);
goto fail1;
}
gpio_direction_output(gpio_ldo_pin, 0);
gpio_set_value(gpio_ldo_pin, 0);
gpio_flag = 0;
gpio_ldo_power_class = class_create(THIS_MODULE, "gpio_ldo_power");
if(IS_ERR(gpio_ldo_power_class))
{
ret = PTR_ERR(gpio_ldo_power_class);
printk("Failed to create class.\n");
return ret;
}
gpio_ldo_power_dev = device_create(gpio_ldo_power_class, NULL, 0, NULL, "gpio_gpio_22");
if (IS_ERR(gpio_ldo_power_dev))
{
ret = PTR_ERR(gpio_ldo_power_class);
printk("Failed to create device(gpio_ldo_power_dev)!\n");
return ret;
}
ret = device_create_file(gpio_ldo_power_dev, &gpio_22_dev_attr);
if(ret)
{
pr_err("%s: gpio_22 creat sysfs failed\n",__func__);
return ret;
}
printk("xcz enter gpio_ldo_power_probe, ok \n");
fail1:
return ret;
}
//硬件卸载时调用
static int gpio_ldo_power_remove(struct platform_device *pdev)
{
device_destroy(gpio_ldo_power_class, 0);
class_destroy(gpio_ldo_power_class);
device_remove_file(gpio_ldo_power_dev, &gpio_22_dev_attr);
return 0;
}
static int gpio_ldo_power_suspend(struct platform_device *pdev,pm_message_t state)
{
return 0;
}
static int gpio_ldo_power_resume(struct platform_device *pdev)
{
return 0;
}
static struct of_device_id gpio_ldo_power_dt_match[] = {
{ .compatible = "xcz,gpio_ldo_power",},
{ },
};
MODULE_DEVICE_TABLE(of, gpio_ldo_power_dt_match);
static struct platform_driver gpio_power_driver = {
.driver = {
.name = "gpio_ldo_power",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(gpio_ldo_power_dt_match),
},
.probe = gpio_ldo_power_probe,
.remove = gpio_ldo_power_remove,
.suspend = gpio_ldo_power_suspend,
.resume = gpio_ldo_power_resume,
};
static __init int gpio_power_init(void)
{
return platform_driver_register(&gpio_power_driver);
}
static void __exit gpio_power_exit(void)
{
platform_driver_unregister(&gpio_power_driver);
}
module_init(gpio_power_init);
module_exit(gpio_power_exit);
MODULE_AUTHOR("GPIO_LDO_POWER, Inc.");
MODULE_DESCRIPTION("XCZ GPIO_LDO_POWER");
MODULE_LICENSE("GPL");
关于高通8053平台i2c和spi配置的学习总结
发表于2016/9/29 17:16:02 858人阅读
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