[PATCH 3/4] Documentation: devicetree: Add cpu clock configuration data binding for Exynos3250
Chanwoo Choi
cw00.choi at samsung.com
Thu Jun 12 23:08:12 PDT 2014
The clock block of Exynos3250 add new properties to support cpu clock provider.
To register cpu clock provider of Exynos3250, must need armclk-provider-table
which includes various dividers to change CPU clock to support Exynos3250 cpufreq.
Cc: Thomas Abraham <thomas.ab at samsung.com>
Cc: Tomasz Figa <t.figa at samsung.com>
Cc: Rob Herring <robh+dt at kernel.org>
Cc: Pawel Moll <pawel.moll at arm.com>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Ian Campbell <ijc+devicetree at hellion.org.uk>
Cc: Kumar Gala <galak at codeaurora.org>
Cc: <devicetree at vger.kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi at samsung.com>
Acked-by: Kyungmin Park <kyungmin.park at samsung.com>
---
.../devicetree/bindings/clock/exynos3250-clock.txt | 32 ++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/Documentation/devicetree/bindings/clock/exynos3250-clock.txt b/Documentation/devicetree/bindings/clock/exynos3250-clock.txt
index aadc9c5..189b506 100644
--- a/Documentation/devicetree/bindings/clock/exynos3250-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos3250-clock.txt
@@ -13,6 +13,25 @@ Required Properties:
- #clock-cells: should be 1.
+- samsung,armclk-divider-table: when the frequency of the APLL is changed
+ the divider clocks in CMU_CPU clock domain also need to be updated. These
+ divider clocks have SoC specific divider clock output requirements for a
+ specific APLL clock speeds. When APLL clock rate is changed, these divider
+ clocks are reprogrammed with pre-determined values in order to maintain the
+ SoC specific divider clock outputs. This property lists the divider values
+ for divider clocks in the CMU_CPU block for supported APLL clock speeds.
+ The format of each entry included in the arm-frequency-table should be
+ as defined below
+
+ cell #1: expected arm clock parent frequency
+ cell #2 ~ cell #7: value of clock divider in the following order
+ corem_ratio, atb_ratio, pclk_dbg_ratio, apll_ratio,
+ copy_ratio, hpm_ratio
+
+- samsung,armclk-cells: defines the number of cells in
+ samsung,armclk-divider-table property. The value of this property depends on
+ the SoC type.
+
Each clock is assigned an identifier and client nodes can use this identifier
to specify the clock which they consume.
@@ -26,6 +45,19 @@ Example 1: An example of a clock controller node is listed below.
compatible = "samsung,exynos3250-cmu";
reg = <0x10030000 0x20000>;
#clock-cells = <1>;
+
+ samsung,armclk-cells = <7>;
+ samsung,armclk-divider-table =
+ <1000000 1 4 7 1 7 7>,
+ <900000 1 3 7 1 7 7>,
+ <800000 1 3 7 1 7 7>,
+ <700000 1 3 7 1 7 7>,
+ <600000 1 3 7 1 7 7>,
+ <500000 1 3 7 1 7 7>,
+ <400000 1 3 7 1 7 7>,
+ <300000 1 3 5 1 7 7>,
+ <200000 1 3 3 1 7 7>,
+ <100000 1 1 1 1 7 7>;
};
Example 2: UART controller node that consumes the clock generated by the clock
--
1.8.0
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