Thread (2 messages) 2 messages, 2 authors, 2016-04-10

[PATCH 2/3] clk: sunxi: Add sun6i/8i PLL video support

From: Maxime Ripard <hidden>
Date: 2016-04-10 09:50:06
Also in: linux-clk, linux-devicetree

Hi,

On Wed, Mar 30, 2016 at 06:50:43PM +0200, Jean-Francois Moine wrote:
quoted hunk
Add the PLL type which is used by the sun6i/8i families for video display.

Signed-off-by: Jean-Francois Moine <redacted>
---
 Documentation/devicetree/bindings/clock/sunxi.txt |  1 +
 drivers/clk/sunxi/clk-sunxi.c                     | 65 +++++++++++++++++++++++
 2 files changed, 66 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index 8c0fda8..ff93aee 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -10,6 +10,7 @@ Required properties:
 	"allwinner,sun4i-a10-pll1-clk" - for the main PLL clock and PLL4
 	"allwinner,sun6i-a31-pll1-clk" - for the main PLL clock on A31
 	"allwinner,sun8i-a23-pll1-clk" - for the main PLL clock on A23
+	"allwinner,sun6i-a31-pll3-clk" - for the video PLL clock
 	"allwinner,sun9i-a80-pll4-clk" - for the peripheral PLLs on A80
 	"allwinner,sun4i-a10-pll5-clk" - for the PLL5 clock
 	"allwinner,sun4i-a10-pll6-clk" - for the PLL6 clock
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
index 0581e1b..270f2a9 100644
--- a/drivers/clk/sunxi/clk-sunxi.c
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -23,6 +23,7 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/log2.h>
+#include <linux/rational.h>
 
 #include "clk-factors.h"
 
@@ -1129,6 +1130,70 @@ CLK_OF_DECLARE(sun6i_pll6, "allwinner,sun6i-a31-pll6-clk",
 	       sun6i_pll6_clk_setup);
 
 /*
+ * sun6i pll3
+ *
+ * if (p == 0) rate = k ? 270MHz : 297MHz
+ * else rate = parent_rate / (m + 1) * (n + 1);
+ */
+static void sun6i_pll3_factors(struct factors_request *req)
+{
+	unsigned long n, m;
+
+	if (req->rate == 270000000) {
+		req->m = 0;
+		req->p = 0;
+		req->k = 0;
+	} else if (req->rate == 297000000) {
+		req->m = 0;
+		req->p = 0;
+		req->k = 1;
+	} else {
+		rational_best_approximation(req->rate,
+					req->parent_rate,
+					1 << 7, 1 << 4, &n, &m);
+		req->rate = req->parent_rate / m * n;
+		req->p = 1;
+		req->m = m - 1;
+		req->n = n - 1;
+	}
+}
+
+static void sun6i_pll3_recalc(struct factors_request *req)
+{
+	if (req->p)
+		req->rate = req->parent_rate / (req->m + 1) * (req->n + 1);
+	else if (req->k)
+		req->rate = 270000000;
+	else
+		req->rate = 297000000;
+}
+
+static const struct clk_factors_config sun6i_pll3_config = {
+	.mshift = 0,
+	.mwidth = 4,
+	.nshift = 8,
+	.nwidth = 7,
+	.pshift = 24,	/* mode selection fractional / integer */
+	.pwidth = 1,
+	.kshift = 25,	/* fraction 270 / 297 MHz */
+	.kwidth = 1,
+};
That's not what p and k are.

Please add extra parameters to deal with fractional rates in the
clk_factors_config (like an extra bit + an array with the two rate
exposed.

That way, you can also deal with it in the core, instead of doing a
hack.

Maxime

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