AM33xx series SoCs do not have autoidle support, and for these the
autoidle register is marked as NULL. Check against a NULL pointer and
do not attempt to of_iomap in this case, as this just creates a bogus
pointer and causes a kernel crash during boot.

Signed-off-by: Tero Kristo <[email protected]>
---
 drivers/clk/omap/dpll.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/omap/dpll.c b/drivers/clk/omap/dpll.c
index 1d24feada..d8a958a 100644
--- a/drivers/clk/omap/dpll.c
+++ b/drivers/clk/omap/dpll.c
@@ -162,6 +162,7 @@ static void __init of_omap_dpll_setup(struct device_node 
*node,
        u32 max_multiplier = 2047;
        u32 max_divider = 128;
        u32 min_divider = 1;
+       u32 val;
        int i;
 
        dd = kzalloc(sizeof(struct dpll_data), GFP_KERNEL);
@@ -210,7 +211,14 @@ static void __init of_omap_dpll_setup(struct device_node 
*node,
 
        dd->control_reg = of_iomap(node, 0);
        dd->idlest_reg = of_iomap(node, 1);
-       dd->autoidle_reg = of_iomap(node, 2);
+       /*
+        * AM33xx DPLLs have no autoidle support, and the autoidle reg
+        * for these is NULL. Do not attempt to of_iomap in this case,
+        * as this just creates a bogus pointer and crashes the kernel.
+        */
+       of_property_read_u32_index(node, "reg", 2 * 2, &val);
+       if (val)
+               dd->autoidle_reg = of_iomap(node, 2);
        dd->mult_div1_reg = of_iomap(node, 3);
 
        dd->idlest_mask = idlest_mask;
-- 
1.7.9.5

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