[PATCH 5.12 126/127] rtc: pcf85063: fallback to parent of_node

Greg Kroah-Hartman
2021-05-24T16:09:22Z

From: Francois Gervais <fgervais@distech-controls.com>

commit 03531606ef4cda25b629f500d1ffb6173b805c05 upstream.

The rtc device node is always NULL.

Since v5.12-rc1-dontuse/3c9ea42802a1fbf7ef29660ff8c6e526c58114f6 this
will lead to a NULL pointer dereference.

To fix this use the parent node which is the i2c client node as set by
devm_rtc_allocate_device().

Using the i2c client node seems to be what other similar drivers do
e.g. rtc-pcf8563.c.

Signed-off-by: Francois Gervais <fgervais@distech-controls.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210310211026.27299-1-fgervais@distech-controls.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/rtc/rtc-pcf85063.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -478,6 +478,7 @@ static struct clk *pcf85063_clkout_regis
{
struct clk *clk;
struct clk_init_data init;
+ struct device_node *node = pcf85063->rtc->dev.parent->of_node;

init.name = "pcf85063-clkout";
init.ops = &pcf85063_clkout_ops;
@@ -487,15 +488,13 @@ static struct clk *pcf85063_clkout_regis
pcf85063->clkout_hw.init = &init;

/* optional override of the clockname */
- of_property_read_string(pcf85063->rtc->dev.of_node,
- "clock-output-names", &init.name);
+ of_property_read_string(node, "clock-output-names", &init.name);

/* register the clock */
clk = devm_clk_register(&pcf85063->rtc->dev, &pcf85063->clkout_hw);

if (!IS_ERR(clk))
- of_clk_add_provider(pcf85063->rtc->dev.of_node,
- of_clk_src_simple_get, clk);
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);

return clk;
}