diff options
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/masters/mxc_w1.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/drivers/w1/masters/mxc_w1.c b/drivers/w1/masters/mxc_w1.c index 741d2bb400ae..da3d0f0ad63c 100644 --- a/drivers/w1/masters/mxc_w1.c +++ b/drivers/w1/masters/mxc_w1.c @@ -75,22 +75,25 @@ static u8 mxc_w1_ds2_reset_bus(void *data) */ 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. - */ + 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); - writeb(MXC_W1_CONTROL_WR(bit), ctrl_addr); + udelay(60); - while (timeout_cnt--) { - if (!(readb(ctrl_addr) & MXC_W1_CONTROL_WR(bit))) - break; + do { + u8 ctrl = readb(dev->regs + MXC_W1_CONTROL); - udelay(1); - } + /* 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 !!(readb(ctrl_addr) & MXC_W1_CONTROL_RDST); + return 0; } static int mxc_w1_probe(struct platform_device *pdev) |