static ssize_t cs5535_gpio_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos)
{
u32 m = iminor(file->f_path.dentry->d_inode);
u32 base = gpio_base + cs5535_lowhigh_base(m);
int rd_bit = 1 << (m & 0x0f);
int i;
char ch;
ssize_t count = 0;
if (*ppos >= ARRAY_SIZE(rm))
return 0;
for (i = *ppos; (i < (*ppos + len)) && (i < ARRAY_SIZE(rm)); i++) {
ch = (inl(base + rm[i].rd_offset) & rd_bit) ?
rm[i].on : rm[i].off;
if (put_user(ch, buf+count))
return -EFAULT;
count++;
}
if ((i == ARRAY_SIZE(rm)) && (count < len)) {
put_user('\n', buf + count);
count++;
}
*ppos += count;
return count;
}
static ssize_t cs5535_gpio_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
u32 m = iminor(file->f_path.dentry->d_inode);
int i, j;
u32 base = gpio_base + cs5535_lowhigh_base(m);
u32 m0, m1;
char c;
m1 = 1 << (m & 0x0F);
m0 = m1 << 16;
for (i = 0; i < len; ++i) {
if (get_user(c, data+i))
return -EFAULT;
for (j = 0; j < ARRAY_SIZE(rm); j++) {
if (c == rm[j].on) {
outl(m1, base + rm[j].wr_offset);
if (c == 'O') {
outl(m0, base + 0x10);
outl(m0, base + 0x14);
}
break;
} else if (c == rm[j].off) {
outl(m0, base + rm[j].wr_offset);
break;
}
}
}
*ppos = 0;
return len;
}
static ssize_t cs5535_gpio_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
u32 m = iminor(file->f_path.dentry->d_inode);
int i, j;
u32 base = gpio_base + cs5535_lowhigh_base(m);
u32 m0, m1;
char c;
/**
* Creates the mask for atomic bit programming.
* The high 16 bits and the low 16 bits are used to set the mask.
* For example, GPIO 15 maps to 31,15: 0,1 => On; 1,0=> Off
*/
m1 = 1 << (m & 0x0F);
m0 = m1 << 16;
for (i = 0; i < len; ++i) {
if (get_user(c, data+i))
return -EFAULT;
for (j = 0; j < ARRAY_SIZE(rm); j++) {
if (c == rm[j].on) {
outl(m1, base + rm[j].wr_offset);
break;
} else if (c == rm[j].off) {
outl(m0, base + rm[j].wr_offset);
break;
}
}
}
*ppos = 0;
return len;
}
