Re: [PATCH] clk: rockchip: add initcall to set clk defaults after syscons are available

From: Kever Yang
Date: Mon Sep 22 2014 - 03:56:25 EST


On 08/07/2014 08:57 PM, Heiko Stübner wrote:
PLLs on Rockchip platforms report their locking state in an external
register situated in the "General Register Files" which is provided
through a syscon device.

When the initial clk init runs, this syscon is of course not yet
available, making it impossible to set PLLs to other frequencies
through the assigned-rate property of the clock-controller node.

Syscon devices are initialized through a postcore initcall, so add an
arch_initcall to rerun the rockchip specific clock initalization when
the GRF is available.

As the clock init already runs two times (through of_clk_add_provider
and of_clk_init), a third time shouldn't hurt to much and in the best
case wouldn't change any settings at all.

Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
drivers/clk/rockchip/clk.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
index 9a3adb1..e14b108 100644
--- a/drivers/clk/rockchip/clk.c
+++ b/drivers/clk/rockchip/clk.c
@@ -23,6 +23,7 @@
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
+#include <linux/clk/clk-conf.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "clk.h"
@@ -126,6 +127,18 @@ void __init rockchip_clk_init(struct device_node *np, void __iomem *base,
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+ * Set clock-defaults again, after grf regmap is available for PLLs.
+ */
+static int __init rockchip_clk_set_defaults(void)
+ if (cru_node)
+ return of_clk_set_defaults(cru_node, true);
+ return 0;
struct regmap *rockchip_clk_get_grf(void)
if (IS_ERR(grf))
This patch works on my rk3288 evb, so,
Tested-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>

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