From e5aef1bbf11412eebd4c242b46adff5301353c30 Mon Sep 17 00:00:00 2001 From: Sam Protsenko Date: Thu, 7 Mar 2024 18:04:32 -0600 Subject: [PATCH] clk: Propagate clk_set_rate() if CLK_SET_PARENT_RATE present Sometimes clocks provided to a consumer might not have .set_rate operation (like gate or mux clocks), but have CLK_SET_PARENT_RATE flag set. In that case it's usually possible to find a parent up the tree which is capable of setting the rate (div, pll, etc). Implement a simple lookup procedure for such cases, to traverse the clock tree until .set_rate capable parent is found, and use that parent to actually change the rate. The search will stop once the first .set_rate capable clock is found, which is usually enough to handle most cases. Signed-off-by: Sam Protsenko --- drivers/clk/clk-uclass.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c index a9937c22dcb..353ae476068 100644 --- a/drivers/clk/clk-uclass.c +++ b/drivers/clk/clk-uclass.c @@ -569,8 +569,20 @@ ulong clk_set_rate(struct clk *clk, ulong rate) return 0; ops = clk_dev_ops(clk->dev); - if (!ops->set_rate) - return -ENOSYS; + /* Try to find parents which can set rate */ + while (!ops->set_rate) { + struct clk *parent; + + if (!(clk->flags & CLK_SET_RATE_PARENT)) + return -ENOSYS; + + parent = clk_get_parent(clk); + if (IS_ERR_OR_NULL(parent) || !clk_valid(parent)) + return -ENODEV; + + clk = parent; + ops = clk_dev_ops(clk->dev); + } /* get private clock struct used for cache */ clk_get_priv(clk, &clkp); -- 2.39.5