Thread (1 message) 1 message, 1 author, 2016-10-10

[PATCH] Reorganize STM32 clocks in order to prepare them for PLLI2S and PLLSAI

From: Daniel Thompson <hidden>
Date: 2016-10-10 09:37:53
Also in: linux-clk, lkml

On 06/10/16 23:01, radek wrote:
quoted hunk
From: Radoslaw Pietrzyk <redacted>

Signed-off-by: Radoslaw Pietrzyk <redacted>
---
 drivers/clk/clk-stm32f4.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
index 02d6810..1fd3eac 100644
--- a/drivers/clk/clk-stm32f4.c
+++ b/drivers/clk/clk-stm32f4.c
@@ -245,9 +245,10 @@ static void stm32f4_rcc_register_pll(const char *hse_clk, const char *hsi_clk)
 	const char   *pllsrc = pllcfgr & BIT(22) ? hse_clk : hsi_clk;
 	unsigned long pllq   = (pllcfgr >> 24) & 0xf;

-	clk_register_fixed_factor(NULL, "vco", pllsrc, 0, plln, pllm);
-	clk_register_fixed_factor(NULL, "pll", "vco", 0, 1, pllp);
-	clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq);
+	clk_register_fixed_factor(NULL, "vco-div", pllsrc, 0, 1, pllm);
+	clk_register_fixed_factor(NULL, "vco-mul", "vco-div", 0, plln, 1);
+	clk_register_fixed_factor(NULL, "pll", "vco-mul", 0, 1, pllp);
+	clk_register_fixed_factor(NULL, "pll48", "vco-mul", 0, 1, pllq);
I'm struggling to marry this up to the clock tree diagram for the 
F4-series (and there's no patch description to help me).

I can see the value of naming the "/M" pre-division separately (and 
agree that its hard to find it a good name for this clock in the 
datasheet). However I am struggling to work out why we'd want to rename 
the vco output.

For me the names for the multiplies clock within each pll emerges fairly 
cleanly from the datasheet (PLL -> vco, PLLI2S -> vcoi2s, PLLSAI -> 
vcosai). What does the '-mul' add?


Daniel.
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