W1_PAGE_MASK
if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);