clk: zynqmp: do not enable already enabled clocks

The pmu fw manages the permissions who can enable/disable the clocks.

There are a few clocks (TOPSW_LSBUS and LSBUS) which are exposed to
Barebox and Barebox assumes that is has to enable the clocks. However,
the pmu fw considers the clocks under its control and returns a
permission denied for the clock enable request.

Assume that clocks that are already enabled don't need to be enable by
Barebox to avoid the permission denied errors.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Link: https://lore.barebox.org/20210624150054.1205422-3-m.tretter@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/clk/zynqmp/clk-gate-zynqmp.c b/drivers/clk/zynqmp/clk-gate-zynqmp.c
index a3b9ee21e5..493c1dfeaa 100644
--- a/drivers/clk/zynqmp/clk-gate-zynqmp.c
+++ b/drivers/clk/zynqmp/clk-gate-zynqmp.c
@@ -28,6 +28,9 @@ static int zynqmp_clk_gate_enable(struct clk_hw *hw)
 {
 	struct zynqmp_clk_gate *gate = to_zynqmp_clk_gate(hw);
 
+	if (clk_hw_is_enabled(hw))
+		return 0;
+
 	return gate->ops->clock_enable(gate->clk_id);
 }