rtc: pcf85063: fallback to parent of_node

BugLink: https://bugs.launchpad.net/bugs/1931896
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index e19cf2adbc355cba0684bd31b75b1a3b9b635e94..9fcf6a6f4da0d22152b6b88a4de451398c5d0993 100644 (file)
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -486,6 +486,7 @@ static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
 {
        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;
@@ -495,15 +496,13 @@ static struct clk *pcf85063_clkout_register_clk(struct pcf85063 *pcf85063)
        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;
 }