clk: clk-gpio: propagate rate change to parent

[ Upstream commit fc59462c5ce60da119568fac325c92fc6b7c6175 ]

For an external clock source, which is gated via a GPIO, the
rate change should typically be propagated to the parent clock.

The situation where we are requiring this propagation, is when an
external clock is connected to override an internal clock (which typically
has a fixed rate). The external clock can have a different rate than the
internal one, and may also be variable, thus requiring the rate
propagation.

This rate change wasn't propagated until now, and it's unclear about cases
where this shouldn't be propagated. Thus, it's unclear whether this is
fixing a bug, or extending the current driver behavior. Also, it's unsure
about whether this may break any existing setups; in the case that it does,
a device-tree property may be added to disable this flag.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lkml.kernel.org/r/20191108071718.17985-1-alexandru.ardelean@analog.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c
index 40af4fbab4d23f24acda1ab07fe1df887131c243..af9cc00d2d920a5565a3ffca2d0176bfc62b3d8b 100644 (file)
--- a/drivers/clk/clk-gpio.c
+++ b/drivers/clk/clk-gpio.c
@@ -248,7 +248,7 @@ static int gpio_clk_driver_probe(struct platform_device *pdev)
        else
                clk = clk_register_gpio_gate(&pdev->dev, node->name,
                                parent_names ?  parent_names[0] : NULL, gpiod,
-                               0);
+                               CLK_SET_RATE_PARENT);
        if (IS_ERR(clk))
                return PTR_ERR(clk);