/*
* this is the low level routine to read/write a bit on the One Wire
* interface on the hardware. It does write 0 if parameter bit is set
* to 0, otherwise a write 1/read.
*/
static u8 mxc_w1_ds2_touch_bit(void *data, u8 bit)
{
struct mxc_w1_device *mdev = data;
void __iomem *ctrl_addr = mdev->regs + MXC_W1_CONTROL;
unsigned int timeout_cnt = 400; /* Takes max. 120us according to
* datasheet.
*/
writeb(MXC_W1_CONTROL_WR(bit), ctrl_addr);
while (timeout_cnt--) {
if (!(readb(ctrl_addr) & MXC_W1_CONTROL_WR(bit)))
break;
udelay(1);
}
return !!(readb(ctrl_addr) & MXC_W1_CONTROL_RDST);
}
/*
* this is the low level routine to read/write a bit on the One Wire
* interface on the hardware. It does write 0 if parameter bit is set
* to 0, otherwise a write 1/read.
*/
static u8 mxc_w1_ds2_touch_bit(void *data, u8 bit)
{
struct mxc_w1_device *dev = data;
unsigned long timeout;
writeb(MXC_W1_CONTROL_WR(bit), dev->regs + MXC_W1_CONTROL);
/* Wait for read/write bit (60us, Max 120us), use 200us for sure */
timeout = jiffies + usecs_to_jiffies(200);
udelay(60);
do {
u8 ctrl = readb(dev->regs + MXC_W1_CONTROL);
/* RDST bit is valid after the WR1/RD bit is self-cleared */
if (!(ctrl & MXC_W1_CONTROL_WR(bit)))
return !!(ctrl & MXC_W1_CONTROL_RDST);
} while (time_is_after_jiffies(timeout));
return 0;
}
