[PATCH] clk: fractional-divider: prevent division by zero

Heikki Krogerus
2015-01-16T12:37:55Z

Preventing division by zero condition by making sure that
the initial n and m values are not 0.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
drivers/clk/clk-fractional-divider.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c
index 82a59d0..dc91da7 100644
--- a/drivers/clk/clk-fractional-divider.c
+++ b/drivers/clk/clk-fractional-divider.c
@@ -104,6 +104,7 @@ struct clk *clk_register_fractional_divider(struct device *dev,
struct clk_fractional_divider *fd;
struct clk_init_data init;
struct clk *clk;
+ u32 val;

fd = kzalloc(sizeof(*fd), GFP_KERNEL);
if (!fd) {
@@ -126,6 +127,14 @@ struct clk *clk_register_fractional_divider(struct device *dev,
fd->lock = lock;
fd->hw.init = &init;

+ /* Prevent division by zero */
+ val = clk_readl(fd->reg);
+ if (!(val & fd->nmask))
+ val |= 1 << fd->nshift;
+ if (!(val & fd->mmask))
+ val |= 1 << fd->mshift;
+ clk_writel(val, fd->reg);
+
clk = clk_register(dev, &fd->hw);
if (IS_ERR(clk))
kfree(fd);
--
2.1.4