[PATCH 2/3] ARM: DRA7x: dts: Fix the 32kHz clock calculation
Tero Kristo
t-kristo at ti.com
Wed Apr 27 04:40:14 PDT 2016
On 26/04/16 20:54, J.D. Schroeder wrote:
> From: "J.D. Schroeder" <jay.schroeder at garmin.com>
>
> This commit fixes the 32kHz clock (sys_32k_ck) calculation to be
> correctly based on the SYS_CLK1 (sys_clkin1) frequency. Based on the
> TRM CTRL_CORE_BOOTSTRAP[9:8] SPEEDSELECT, set by the SYSBOOT[9:8]
> board jumpers according to the SYS_CLK1 frequency, the frequency of
> the 32kHz FUNC_32K_CLK is set to SYS_CLK1/610. The following
> sys_32k_ck frequencies get used for different SYS_CLK1 frequencies:
> 0b00: Unknown -> 32768 Hz crystal from CLKIN_32K pin
> 0b01: 20 MHz -> 32787 Hz clock (SYS_CLK1/610)
> 0b10: 27 MHz -> 44262 Hz clock (SYS_CLK1/610)
> 0b11: 19.2 MHz -> 31475 Hz clock (SYS_CLK1/610)
>
> Signed-off-by: J.D. Schroeder <jay.schroeder at garmin.com>
> Reviewed-by: Ben McCauley <ben.mccauley at garmin.com>
A patch doing the same thing is already in mainline, see:
commit eea08802f586acd6aef377d1b4a541821013cc0b
Author: Keerthy <j-keerthy at ti.com>
Date: Mon Apr 4 11:07:15 2016 +0530
ARM: dts: dra7: Correct clock tree for sys_32k_ck
So, this one can be ignored.
-Tero
> ---
> arch/arm/boot/dts/dra7xx-clocks.dtsi | 28 ++++++++++++++++++++++------
> 1 file changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/boot/dts/dra7xx-clocks.dtsi b/arch/arm/boot/dts/dra7xx-clocks.dtsi
> index 9d1a583..a514fc3 100644
> --- a/arch/arm/boot/dts/dra7xx-clocks.dtsi
> +++ b/arch/arm/boot/dts/dra7xx-clocks.dtsi
> @@ -98,12 +98,6 @@
> clock-frequency = <32768>;
> };
>
> - sys_32k_ck: sys_32k_ck {
> - #clock-cells = <0>;
> - compatible = "fixed-clock";
> - clock-frequency = <32768>;
> - };
> -
> virt_12000000_ck: virt_12000000_ck {
> #clock-cells = <0>;
> compatible = "fixed-clock";
> @@ -2177,4 +2171,26 @@
> ti,bit-shift = <22>;
> reg = <0x0558>;
> };
> +
> + sys_32kin: sys_32kin {
> + #clock-cells = <0>;
> + compatible = "fixed-clock";
> + clock-frequency = <32768>;
> + };
> +
> + sys_clkin1_32k_div: sys_clkin1_32k_div {
> + #clock-cells = <0>;
> + compatible = "fixed-factor-clock";
> + clocks = <&sys_clkin1>;
> + clock-mult = <1>;
> + clock-div = <610>;
> + };
> +
> + sys_32k_ck: sys_32k_ck {
> + #clock-cells = <0>;
> + compatible = "ti,mux-clock";
> + clocks = <&sys_32kin>, <&sys_clkin1_32k_div>, <&sys_clkin1_32k_div>, <&sys_clkin1_32k_div>;
> + ti,bit-shift = <8>;
> + reg = <0x06c4>;
> + };
> };
>
More information about the linux-arm-kernel
mailing list