diff options
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/masters/mxc_w1.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/w1/masters/mxc_w1.c b/drivers/w1/masters/mxc_w1.c index 5de3ca9b0fb9..953168c63392 100644 --- a/drivers/w1/masters/mxc_w1.c +++ b/drivers/w1/masters/mxc_w1.c @@ -105,6 +105,7 @@ static u8 mxc_w1_ds2_touch_bit(void *data, u8 bit) static int mxc_w1_probe(struct platform_device *pdev) { struct mxc_w1_device *mdev; + unsigned long clkrate; struct resource *res; unsigned int clkdiv; int err = 0; @@ -118,7 +119,16 @@ static int mxc_w1_probe(struct platform_device *pdev) if (IS_ERR(mdev->clk)) return PTR_ERR(mdev->clk); - clkdiv = (clk_get_rate(mdev->clk) / 1000000) - 1; + clkrate = clk_get_rate(mdev->clk); + if (clkrate < 10000000) + dev_warn(&pdev->dev, + "Low clock frequency causes improper function\n"); + + clkdiv = DIV_ROUND_CLOSEST(clkrate, 1000000); + clkrate /= clkdiv; + if ((clkrate < 980000) || (clkrate > 1020000)) + dev_warn(&pdev->dev, + "Incorrect time base frequency %lu Hz\n", clkrate); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); mdev->regs = devm_ioremap_resource(&pdev->dev, res); @@ -126,7 +136,7 @@ static int mxc_w1_probe(struct platform_device *pdev) return PTR_ERR(mdev->regs); clk_prepare_enable(mdev->clk); - __raw_writeb(clkdiv, mdev->regs + MXC_W1_TIME_DIVIDER); + __raw_writeb(clkdiv - 1, mdev->regs + MXC_W1_TIME_DIVIDER); mdev->bus_master.data = mdev; mdev->bus_master.reset_bus = mxc_w1_ds2_reset_bus; |