linux kernel - How to connect ov5642 camera module Pixel clock (8MHz) to imx6 quad -

i using i.mx6quad debian jessie (3.14.60-fslc-imx6-sr).

i want co connect ov5642 camera module parallel 8bit interface (using 8gpios data , 3 control signals). wrote linux kernel module service interrupts control signals. interrupts vsync , href signals serviced when connect pclk (about 8mhz) signal faster href or vsync linux hangs untill disconnect wire pclk (everything stucks). connect pclk use gpio90 (disp1_data22) tried other gpios.

now question gpio should use service such fast signals pclk or can avoid linux hang ups ??

i include linux kernel module code use.

#include<linux/init.h> #include<linux/module.h> #include<linux/kernel.h> #include<linux/gpio.h> #include<linux/interrupt.h>  static unsigned int vsync_gpio_number=79; static unsigned int href_gpio_number=76; static unsigned int pclk_gpio_number=90; static unsigned int vsync_irqnumber; static unsigned int href_irqnumber; static unsigned int pclk_irqnumber;  static irq_handler_t vsync_gpio_irq_handler(unsigned int irq,void *dev_id,struct pt_regs *regs); static irq_handler_t href_gpio_irq_handler(unsigned int irq,void *dev_id,struct pt_regs *regs); static irq_handler_t pclk_gpio_irq_handler(unsigned int irq,void *dev_id,struct pt_regs *regs);   int __init camera_module_test_init(void){//init_module()      int result=0;      printk(kern_info "gpio_test: initializing gpio_test lkm\n"); //vsync init     if(!gpio_is_valid(vsync_gpio_number)){         printk(kern_info "gpio test: invalid vsync gpio\n");         return -enodev;     } //href init     if(!gpio_is_valid(href_gpio_number)){     printk(kern_info "gpio test: invalid href gpio\n");     return -enodev;      } //pclk init     if(!gpio_is_valid(pclk_gpio_number)){     printk(kern_info "gpio test: invalid pclk gpio\n");     return -enodev;     }      //ledon=true; //vsync     gpio_request(vsync_gpio_number,"sysfs");     gpio_direction_input(vsync_gpio_number);         gpio_export(vsync_gpio_number,false);  // causes gpiox appear in sysfs /sys/class/gpio/ //href     gpio_request(href_gpio_number,"sysfs");     gpio_direction_input(href_gpio_number);     gpio_export(href_gpio_number,false); //pclk     gpio_request(pclk_gpio_number,"sysfs");     gpio_direction_input(pclk_gpio_number);     gpio_export(pclk_gpio_number,false);       // gpio numbers , irq numbers not same //mapping   gpio numbers irq numbers //---------     vsync_irqnumber = gpio_to_irq(vsync_gpio_number);     printk(kern_info "gpio_test: vsync signal mapped irq: %d\n",vsync_irqnumber);     //     href_irqnumber=gpio_to_irq(href_gpio_number);     printk(kern_info "gpio test: href signal mapped irq: %d\n",href_irqnumber);     //     pclk_irqnumber=gpio_to_irq(pclk_gpio_number);     printk(kern_info "gpio test: pclk signal mapped irq: %d\n",pclk_irqnumber);      //requests interrupt line //vsync      result=request_irq(vsync_irqnumber,(irq_handler_t)vsync_gpio_irq_handler,irqf_trigger_rising,"vsync_gpio_handler",null);     if(result==0){  //if success         printk(kern_info "gpio_test: vsync interrupt request result is: %d\n",result);         }            else{     printk(kern_info "gpio_test: vsync interrupt request fail !!! (%d)\n",result);       return result;       } //href       result=request_irq(href_irqnumber,(irq_handler_t)href_gpio_irq_handler,irqf_trigger_rising,"href_gpio_handler",null);     if(result==0){ //if success     printk(kern_info "gpio_test: href interrupt request result is: %d\n",result);     }     else{     printk(kern_info "gpio_test: href interrupt request fail !!! (%d)\n",result);     return result;       } //pclk     result=request_irq(pclk_irqnumber,(irq_handler_t)pclk_gpio_irq_handler,irqf_trigger_rising,"pclk_gpio_handler",null);        if(result==0){// if success     printk(kern_info "gpio_test: pclk interrupt request result is: %d\n",result);     }     else{     printk(kern_info "gpio_test: pclk interrupt request fail !!! (%d)\n",result);        return result;     }      printk(kern_info "module loaded.... waiting interruption\n");         return result; }  static void __exit camera_module_test_exit(void){ //cleanup_module(void){     printk(kern_info "exiting camera_lkm_module_test\n");  //unexporting gpios     gpio_unexport(vsync_gpio_number);     gpio_unexport(href_gpio_number);     gpio_unexport(pclk_gpio_number); //freeing irqs     free_irq(vsync_irqnumber,null);     free_irq(href_irqnumber,null);     free_irq(pclk_irqnumber,null); //freeing memory     gpio_free(vsync_gpio_number);     gpio_free(href_gpio_number);     gpio_free(pclk_gpio_number);      printk(kern_info "goodbye world - module closed\n"); }   static irq_handler_t vsync_gpio_irq_handler(unsigned int irq,void *dev_id,struct pt_regs *regs){     printk(kern_info "* vsync interrupt on rising! *\n");      return (irq_handler_t)irq_handled; }  static irq_handler_t href_gpio_irq_handler(unsigned int irq,void *dev_id,struct pt_regs *regs){     printk(kern_info "-- href interrupt! on rising --\n");      return (irq_handler_t)irq_handled;   }  static irq_handler_t pclk_gpio_irq_handler(unsigned int irq,void *dev_id,struct pt_regs *regs){     printk(kern_info "// pclk interrupt! on rising //\n");      return (irq_handler_t)irq_handled; }  module_init(camera_module_test_init); module_exit(camera_module_test_exit);  module_license("gpl"); 

i can add using hummingboard gate available gpios shown in attached image.

hummingboard gate available gpios