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66 lines
1.4 KiB
66 lines
1.4 KiB
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static uint8_t readBuffer(void){
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uint8_t ret;
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if(buff_empty){
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return 0;
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}
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ret=buffer[buff_end];
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buff_end++;
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if(buff_end==BUFFER_SIZE){
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buff_end=0;
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}
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if(buff_end==buff_start){
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buff_empty=1;
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}
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return ret;
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}
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static uint8_t writeToBuffer(uint8_t data){
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if(buff_start==buff_end && !buff_empty){
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/*overrun*/
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printk("<1>%s: Buffer overrun!\n",MOD_NAME);
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return 1;
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}
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buffer[buff_start]=data;
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buff_start++;
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if(buff_start==BUFFER_SIZE){
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buff_start=0;
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}
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buff_empty=0;
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return 0;
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}
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static ssize_t device_read(struct file *filp, char __user *buffer, size_t length, loff_t *offset){
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uint8_t val;
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if(!buff_empty){
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val = readBuffer();
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DEBUG_OUT("<1>%s: device_read invoked writing: mem[%x]=%02x\n",MOD_NAME,buffer,val);
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if( copy_to_user(buffer,&val,1)<0 ){
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printk("<1>%s: Device read error!\n",MOD_NAME);
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return 0;
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}
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return 1;
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}
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return 0;
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}
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static ssize_t device_write(struct file *filp, const char __user *buff, size_t len, loff_t *off){
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int ret;
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DEBUG_OUT("<1>%s: device_write invoked\n",MOD_NAME);
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if(len!=1){
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return -EINVAL;
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}
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ret = copy_from_user(pin_status, buff, len);
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if( ret<0 ){
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printk("<1>%s: Device write error!\n",MOD_NAME);
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return 0;
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}
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n_written=0;
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return len;
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}
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struct file_operations fops = {
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read: device_read,
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write: device_write,
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};
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