1
0
mirror of https://github.com/richardghirst/PiBits.git synced 2025-02-20 14:54:14 +01:00

Add dev_read() function to driver to allow it to report current settings

for each of the 8 PWMs via /dev/servoblaster.
This commit is contained in:
Robin Mallinson 2012-11-05 22:23:45 +00:00
parent da669a303d
commit fd2d771d1e

View File

@ -323,7 +323,55 @@ static int dev_open(struct inode *inod,struct file *fil)
static ssize_t dev_read(struct file *filp,char *buf,size_t count,loff_t *f_pos)
{
#if 0
int servo;
static int idx=0;
// Allow 10 chars per line:
static char returnedData[NUM_SERVOS * 10] = {0};
if (0 == *f_pos)
{
// Get fresh data
for (servo=0, idx=0; servo < NUM_SERVOS; ++servo)
{
if (wait_for_servo(servo))
return -EINTR;
idx += snprintf(returnedData+idx, sizeof(returnedData)-idx,
"%i %lu\n",
servo,
ctl->cb[servo*4+1].length / sizeof(uint32_t)
);
}
}
if (*f_pos >= idx)
{
//EOF
return 0;
}
else if ( (*f_pos + count) < idx )
{
// Sufficient data to fulfil request
if (copy_to_user(buf,returnedData+fpos,count) {
return -EFAULT;
}
*f_pos+=count;
return count;
}
else
{
// Return all the data we have
const int nBytes = idx-*f_pos;
if (copy_to_user(buf,returnedData+*f_pos, nBytes) {
return -EFAULT;
}
*f_pos+=nBytes;
return nBytes;
}
#else
return 0;
#endif
}
static ssize_t dev_write(struct file *filp,const char *buf,size_t count,loff_t *f_pos)