The backend needs to run at 300MHz to be functional. This was done so far
using assigned-clocks in the device tree, but that is easy to forget, and
dosen't provide any other guarantee than the rate is going to be roughly
the one requested at probe time.
Therefore it's pretty fragile, so let's just use the exclusive clock API to
enforce it.
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
---
drivers/gpu/drm/sun4i/sun4i_backend.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index 4e29f4fe4a05..aa55eaeb8823 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -857,6 +857,7 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
goto err_disable_bus_clk;
}
clk_prepare_enable(backend->mod_clk);
+ clk_set_rate_exclusive(backend->mod_clk, 300000000);
backend->ram_clk = devm_clk_get(dev, "ram");
if (IS_ERR(backend->ram_clk)) {
@@ -932,6 +933,7 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
err_disable_ram_clk:
clk_disable_unprepare(backend->ram_clk);
err_disable_mod_clk:
+ clk_rate_exclusive_put(backend->mod_clk);
clk_disable_unprepare(backend->mod_clk);
err_disable_bus_clk:
clk_disable_unprepare(backend->bus_clk);
@@ -952,6 +954,7 @@ static void sun4i_backend_unbind(struct device *dev, struct device *master,
sun4i_backend_free_sat(dev);
clk_disable_unprepare(backend->ram_clk);
+ clk_rate_exclusive_put(backend->mod_clk);
clk_disable_unprepare(backend->mod_clk);
clk_disable_unprepare(backend->bus_clk);
reset_control_assert(backend->reset);
--
2.23.0
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