Thread (47 messages) 47 messages, 5 authors, 2014-07-07

[PATCH v2 05/20] clk: sunxi: Support factor clocks with N multiplier factor starting from 1

From: Maxime Ripard <hidden>
Date: 2014-06-18 09:45:39
Also in: linux-devicetree, linux-serial, lkml

On Tue, Jun 17, 2014 at 10:52:42PM +0800, Chen-Yu Tsai wrote:
quoted hunk ↗ jump to hunk
The PLLs on newer Allwinner SoC's, such as the A31 and A23, have a
N multiplier factor that starts from 1, not 0.

This patch adds an option to the clock driver's config data structures
to define the difference.

Signed-off-by: Chen-Yu Tsai <redacted>
Acked-by: Maxime Ripard <redacted>
---
 drivers/clk/sunxi/clk-factors.c | 5 ++++-
 drivers/clk/sunxi/clk-factors.h | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
index 3806d97..399cf4d 100644
--- a/drivers/clk/sunxi/clk-factors.c
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -62,7 +62,10 @@ static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
 		p = FACTOR_GET(config->pshift, config->pwidth, reg);
 
 	/* Calculate the rate */
-	rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
+	if (config->n_from_one)
+		rate = (parent_rate * (n + 1) * (k + 1) >> p) / (m + 1);
+	else
+		rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
Thinking a bit more about this, I wonder wether it wouldn't be better
to just have a n_start variable or something, and just use (n +
n_start) instead.

That would avoid having to declare twice the same function.

Maxime
quoted hunk ↗ jump to hunk
 
 	return rate;
 }
diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
index 02e1a43..0484a48 100644
--- a/drivers/clk/sunxi/clk-factors.h
+++ b/drivers/clk/sunxi/clk-factors.h
@@ -15,6 +15,7 @@ struct clk_factors_config {
 	u8 mwidth;
 	u8 pshift;
 	u8 pwidth;
+	u8 n_from_one;
Especially when you declare it as an u8, and not a bool.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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