说明
其实只是一个简单的gpio驱动，但是因为某些问题一直无法实现对背光灯的控制，最后发现原来是某些函数接口的更改，或者说是所支持的接口不一致导致的问题。
在驱动中，
irq_of_parse_and_map(BLgpio_node,0);
gpio_to_irq(blgpio_state2_pin);
原本一直使用的是gpio_to_irq，但是返回值为-22,
以为是硬件管脚相关的配置问题，后来检查没有发现任何问题
然后就尝试使用irq_of_parse_and_map这个接口
一开始我心里是恐惧的，不知道该如何调用以及相关参数是如何修改等等问题，一直迟迟不动，后来就像试试吧，并且在头文件中添加如下：
extern unsigned int irq_of_parse_and_map(struct device_node* dev, int index);
就是这简单的一句，就成功的把该接口调用起来了
但是问题还没有解决，还是没办法正常的，在设备树中只是做了上升沿或下降沿触发的方式中断，然后修改成如下即可：
注意：IRQ_TYPE_EDGE_RISING
find ./kernel-4.9/include/ -name "irq.h"
vi ./kernel-4.9/include/dt-bindings/interrupt-controller/irq.h
#ifndef _DT_BINDINGS_INTERRUPT_CONTROLLER_IRQ_H
#define _DT_BINDINGS_INTERRUPT_CONTROLLER_IRQ_H
#define IRQ_TYPE_NONE 0
#define IRQ_TYPE_EDGE_RISING 1
#define IRQ_TYPE_EDGE_FALLING 2
#define IRQ_TYPE_EDGE_BOTH (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)
#define IRQ_TYPE_LEVEL_HIGH 4
#define IRQ_TYPE_LEVEL_LOW 8
#endif
flyrdgpio:flyrdgpio {
compatible = "mediatek,flyrdgpio";
apstate_scone_gpio=<&pio 152 0>;
apstate_sctwo_gpio=<&pio 151 0>;
apstate_acc_gpio=<&pio 0 0>;
apstate_led_gpio=<&pio 4 0>;
apstate_backlight_gpio=<&pio 164 0>;
interrupt-parent = <&pio>;
interrupts = <151 IRQ_TYPE_EDGE_RISING 151 0>;
fly_amp_mute_=<&pio 165 0>;
fly_dsi_irq=<&pio 3 0>;
fly_gps_ant_en=<&pio 175 0>;
fly_gpro_acc_in=<&pio 48 0>;
fly_ek1=<&pio 9 0>;
fly_ek3=<&pio 4 0>;
fly_gyro_gry_int=<&pio 49 0>;
fly_camera_power=<&pio 167 0>;
status="okay";
};
头文件
#ifndef __BACKLIGHTGPIO_H_
#define __BACKLIGHTGPIO_H_
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <generated/autoconf.h>
#include <linux/platform_device.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/spinlock.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/irq.h>
#include <asm/atomic.h>
#include <linux/of_gpio.h>
#include <linux/time.h>
#include <linux/types.h>
#include <linux/poll.h>
#include <linux/interrupt.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#define AP_STATE1_H "ap_state1_h"
#define AP_STATE2_H "ap_state2_h"
#define AP_STATE3_H "ap_state3_h"
#define AP_I2C_C2_L "i2c_c2_h"
#define AP_I2C_C2 "i2c_c2_ch"
#define AP_PIN_NUM 2
#define AP_PIN_STRDES 30
#define TAG "backlightgpio"
#define fly_pr_info(fmt, arg...) printk(KERN_WARNING fmt, ##arg)
#define FLYGPIO_DEBUG_ON 1
#define FLYGPIO_DEBUG(fmt, arg...) do {\
if (FLYGPIO_DEBUG_ON)\
fly_pr_info("<<-DEBUG->> [%d]"fmt"\n", __LINE__, ##arg);\
} while (0)
struct work_struct work;
enum AccStatus{
IN_SLEEP_STATUS=0,
WAKE_UP_STATUS ,
};
enum FLY_DRIVER_RETURN {
FLY_DRIVER_RETURN_SUCCESS = 0,
FLY_DRIVER_RETURN_ERROR = -1,
};
static DECLARE_WAIT_QUEUE_HEAD(wq);
extern void Set_Camera_power(int value);
extern void driver_cfg_gpio_init(void);
extern void driver_cfg_gpio_exit(void);
extern void driver_cfg_led_init(void);
extern void driver_cfg_led_exit(void);
extern unsigned int irq_of_parse_and_map(struct device_node* dev, int index);
#endif
背光控制驱动
#include "backlightgpio.h"
static struct device_node *BLgpio_node = NULL;
static int blgpio_state2_pin = -1;
static int rdgpio_acc_pin = -1;
static int blgpio_backlight_pin = -1;
static int carback_state_old=-1;
static int carback_state_new=-1;
int condition = 0;
static int BL_gpio_open(struct inode *inode, struct file *file);
static int BL_gpio_release(struct inode *inode, struct file *file);
static ssize_t BL_gpio_read(struct file *filp, char __user *user_buffer, size_t count, loff_t *offset);
static ssize_t BL_gpio_write(struct file *pFile, const char __user *pBuffer, size_t Count, loff_t *p_off);
static unsigned int BL_gpio_poll(struct file *filp, struct poll_table_struct *p);
static void BLgpio_init(void);
static void tsk_work_handler(struct work_struct *work);
irqreturn_t BL_status_handler(int irq,void *date);
static int set_BLgpio_to_irq(void);
static void BLgpio_init(void)
{
int ret = -1;
#if 0
ret = gpio_request(blgpio_state2_pin, "rdgpio_state2_pin");
if (ret < 0) {
FLYGPIO_DEBUG("@@blgpio_state2_pin gpio bc_failed\n");
}
gpio_direction_input(blgpio_state2_pin);
FLYGPIO_DEBUG("@@blgpio_state2_pin gpio ok\n");
#endif
ret = gpio_request(blgpio_backlight_pin, "apstate_backlight_gpio");
if (ret < 0) {
FLYGPIO_DEBUG("@@blgpio_backlight_pin gpio bc_failed\n");
}
FLYGPIO_DEBUG("@@blgpio_backlight_pin gpio ok\n");
gpio_direction_output(blgpio_backlight_pin,1);
}
static void tsk_work_handler(struct work_struct *work)
{
int val = -1;
FLYGPIO_DEBUG("@@handler is running..\n");
val = gpio_get_value(blgpio_state2_pin);
carback_state_new = val;
FLYGPIO_DEBUG("@@carback_state_new = %d, carback_state_old = %d.\n", carback_state_new, carback_state_old);
if(carback_state_new != carback_state_old)
{
condition = 1;
if(carback_state_new == WAKE_UP_STATUS)
{
FLYGPIO_DEBUG("@@handler is running set blgpio_backlight_pin HEIGHT\n");
gpio_set_value(blgpio_backlight_pin ,1);
}
else if(carback_state_new == IN_SLEEP_STATUS)
{
FLYGPIO_DEBUG("@@handler is running set blgpio_backlight_pin LOW\n");
gpio_set_value(blgpio_backlight_pin ,0);
}
wake_up_interruptible(&wq);
}
FLYGPIO_DEBUG("@@handler is running end in outside\n");
}
irqreturn_t BL_status_handler(int irq,void *date)
{
if(!work_pending(&work))
{
FLYGPIO_DEBUG("@@In BL_status_handler.\n");
schedule_work(&work);
}
return IRQ_HANDLED;
}
static int set_BLgpio_to_irq(void)
{
int ret = -1;
int irq = -1;
ret = gpio_request(blgpio_state2_pin, "apstate_sctwo_gpio");
if (ret < 0) {
FLYGPIO_DEBUG("@@apstate_sctwo_gpio gpio bc_failed\n");
return -1;
}
gpio_direction_input(blgpio_state2_pin);
FLYGPIO_DEBUG("@@##blgpio_state2_pin %d\n", blgpio_state2_pin);
irq = irq_of_parse_and_map(BLgpio_node,0);
FLYGPIO_DEBUG("@@request irq is %d\n", irq);
if(irq < 0)
{
FLYGPIO_DEBUG("@@request irq is failed \n");
return -1;
}
else
{
FLYGPIO_DEBUG("@@@request irq apstate_sctwo_gpio.");
ret = request_irq(irq,
BL_status_handler,
IRQF_TRIGGER_FALLING|IRQF_TRIGGER_RISING,
"flyd-irq",
NULL);
FLYGPIO_DEBUG("@@refunction irq %d\n",ret);
ret = gpio_get_value(blgpio_state2_pin);
FLYGPIO_DEBUG("@@carback_state_new = %d, carback_state_old = %d.\n", ret , carback_state_old);
}
return 0;
}
static const struct file_operations BL_gpio_fops = {
.open = BL_gpio_open,
.release = BL_gpio_release,
.read = BL_gpio_read,
.write = BL_gpio_write,
.poll = BL_gpio_poll
};
static struct miscdevice BL_gpio_misc_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "BLgpio",
.fops = &BL_gpio_fops,
};
static int BL_gpio_open(struct inode *inode, struct file *file)
{
FLYGPIO_DEBUG("@@BL_gpio_open. \r\n");
return 0;
}
static int BL_gpio_release(struct inode *inode, struct file *file)
{
FLYGPIO_DEBUG("@@BL_gpio_release. \r\n");
return 0;
}
static ssize_t BL_gpio_read(struct file *filp, char __user *user_buffer, size_t count, loff_t *offset)
{
int pin = 3;
char buffer[30] = {
0};
if(carback_state_new == carback_state_old)
{
if(wait_event_interruptible(wq, carback_state_new != carback_state_old))
{
return -1;
}
}
carback_state_old = carback_state_new;
sprintf(buffer,"%d%5d",pin,carback_state_new);
if(copy_to_user(user_buffer, buffer, count))
{
FLYGPIO_DEBUG("@@cp to user failed \r\n");
}
return count;
}
static ssize_t BL_gpio_write(struct file *pFile, const char __user *pBuffer, size_t Count, loff_t *p_off)
{
char readbuf[30];
int ret_cnt;
int CopyBufSize = (Count < (sizeof(readbuf) - 1)) ? (Count) : (sizeof(readbuf) - 1);
int pin,value;
if (copy_from_user(readbuf, pBuffer, CopyBufSize))
{
FLYGPIO_DEBUG("@@copy_from_user() fail.\r\n");
return -1;
}
FLYGPIO_DEBUG("@@hello write buffer :%s\n",readbuf);
ret_cnt = sscanf(readbuf, "%d %d",&pin, &value);
if(ret_cnt < 1)
{
FLYGPIO_DEBUG("@@ret_cnt != 2 fail.\r\n");
return -1;
}
if((pin > AP_PIN_NUM )|| (pin <= 0) )
{
FLYGPIO_DEBUG("@@set pin is 1------8 please \r\n");
return -1;
}
if(value > 1 || value < 0)
{
FLYGPIO_DEBUG("@@set pin value is 0 or 1\r\n");
return -1;
}
FLYGPIO_DEBUG("@@you write pindes %d,value = %d \n",pin,value);
if(pin == 1){
;
}
else if(pin == 2)
{
gpio_set_value(blgpio_state2_pin,value);
FLYGPIO_DEBUG("@@##set pin value is %d\r\n", value);
}
return ((ssize_t)Count);
}
static unsigned int BL_gpio_poll(struct file *filp, struct poll_table_struct *p)
{
unsigned int mask = 0;
poll_wait(filp, &wq, p);
if(condition == 1)
{
mask |= POLLIN | POLLRDNORM;
}
else
{
mask = 0;
}
condition = 0;
return mask;
}
static int BL_gpio_probe(struct platform_device *pdev)
{
int ret = 0;
FLYGPIO_DEBUG("@@BL gpio Probe. \r\n");
ret = misc_register(&BL_gpio_misc_device);
if (ret != 0 )
printk(": BL_gpio_misc_device flygpio_device register failed\n");
INIT_WORK(&work, tsk_work_handler);
return ret;
}
static int BL_gpio_remove(struct platform_device *pdev)
{
FLYGPIO_DEBUG("@@BL gpio remove. \r\n");
misc_deregister(&BL_gpio_misc_device);
return 0;
}
static struct platform_driver BLgpio_driver = {
.driver = {
.name = "BLgpio-dev",
.owner = THIS_MODULE,
},
.remove = BL_gpio_remove,
.probe = BL_gpio_probe,
};
static struct platform_device BLgpio_device = {
.name = "BLgpio-dev",
.id = -1,
};
static int __init backlight_gpio_init(void)
{
int ret = 0;
FLYGPIO_DEBUG("@@backlight_gpio_init. \r\n");
ret = gpio_get_value(blgpio_state2_pin);
FLYGPIO_DEBUG("@@carback_state_new = %d, carback_state_old = %d.\n", ret , carback_state_old);
ret = platform_device_register(&BLgpio_device);
if(ret)
{
FLYGPIO_DEBUG("@@platform_device_register failed!");
goto err;
}
FLYGPIO_DEBUG("@@platform_device_register ok!");
ret = platform_driver_register(&BLgpio_driver);
if(ret)
{
FLYGPIO_DEBUG("@@platform_driver_register failed!");
platform_device_unregister(&BLgpio_device);
return ret;
}
FLYGPIO_DEBUG("@@platform_driver_register ok!");
BLgpio_node = of_find_compatible_node(NULL, NULL, "mediatek,flyrdgpio");
if(BLgpio_node)
{
blgpio_state2_pin = of_get_named_gpio(BLgpio_node, "apstate_sctwo_gpio", 0);
if (!gpio_is_valid(blgpio_state2_pin))
{
FLYGPIO_DEBUG("@@rdgpio_state2_pin bc_failed\n");
}
FLYGPIO_DEBUG("@@rdgpio_state2_pin ok\n");
#if 0
rdgpio_acc_pin = of_get_named_gpio(BLgpio_node,"apstate_acc_gpio", 0);
if (!gpio_is_valid(rdgpio_acc_pin)) {
FLYGPIO_DEBUG("@@rdgpio_acc_pin bc_failed\n");
}
FLYGPIO_DEBUG("@@rdgpio_acc_pin ok\n");
#endif
blgpio_backlight_pin = of_get_named_gpio(BLgpio_node,"apstate_backlight_gpio", 0);
if (!gpio_is_valid(blgpio_backlight_pin)) {
FLYGPIO_DEBUG("@@blgpio_backlight_pin bc_failed\n");
}
FLYGPIO_DEBUG("@@blgpio_backlight_pin ok\n");
}
FLYGPIO_DEBUG("@@my_find_ok blgpio_state2_pin=%d,rdgpio_acc_pin=%d,blgpio_backlight_pin=%d\r\n",
blgpio_state2_pin,
rdgpio_acc_pin,
blgpio_backlight_pin );
ret = gpio_get_value(blgpio_state2_pin);
FLYGPIO_DEBUG("@@carback_state_new = %d, carback_state_old = %d.\n", ret , carback_state_old);
BLgpio_init();
set_BLgpio_to_irq();
ret = gpio_get_value(blgpio_state2_pin);
FLYGPIO_DEBUG("@@carback_state_new = %d, carback_state_old = %d.\n", ret , carback_state_old);
return 0;
err:
FLYGPIO_DEBUG("backlight_gpio_init with err exit.");
return ret;
}
static void __exit backlight_gpio_exit(void)
{
FLYGPIO_DEBUG("@@backlight_gpio_exit. \r\n");
platform_driver_unregister(&BLgpio_driver);
platform_device_unregister(&BLgpio_device);
}
module_init(backlight_gpio_init);
module_exit(backlight_gpio_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MY General Purpose Driver (GPIO)");