ARM: imx: provide twd clock lookup from device tree

While booting from device tree, imx6q used to provide twd clock lookup
by calling clk_register_clkdev() in clock driver.  However, the commit
bd60345 (ARM: use device tree to get smp_twd clock) forces DT boot to
look up the clock from device tree.  It causes the failure below when
twd driver tries to get the clock, and hence kernel has to calibrate the
local timer frequency.

 smp_twd: clock not found -2
 ...
 Calibrating local timer... 396.13MHz.

Fix the regression by providing twd clock lookup from device tree, and
remove the unused twd clk_register_clkdev() call from clock driver.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index 06ec460b4581c4163e4053953e84acfaad01a76b..281a223591ff83d5a9eef96c6775c77c99a356ad 100644 (file)
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -91,6 +91,7 @@
                        compatible = "arm,cortex-a9-twd-timer";
                        reg = <0x00a00600 0x20>;
                        interrupts = <1 13 0xf01>;
+                       clocks = <&clks 15>;
                };
 
                L2: l2-cache@00a02000 {

diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c
index 2f9ff93a4e6134773befacb68c4dd4ec5c14bb90..22a3021a455b144b4240f5418e4ebcecf95a6c11 100644 (file)
--- a/arch/arm/mach-imx/clk-imx6q.c
+++ b/arch/arm/mach-imx/clk-imx6q.c
@@ -443,7 +443,6 @@ int __init mx6q_clocks_init(void)
 
        clk_register_clkdev(clk[gpt_ipg], "ipg", "imx-gpt.0");
        clk_register_clkdev(clk[gpt_ipg_per], "per", "imx-gpt.0");
-       clk_register_clkdev(clk[twd], NULL, "smp_twd");
        clk_register_clkdev(clk[cko1_sel], "cko1_sel", NULL);
        clk_register_clkdev(clk[ahb], "ahb", NULL);
        clk_register_clkdev(clk[cko1], "cko1", NULL);