[PATCH v4 4/8] Documentation: devicetree: add cpu clock configuration data binding for Exynos4/5

Thomas Abraham
2014-05-14T01:11:12Z

From; Thomas Abraham <thomas.ab@samsung.com>

The clock blocks within the CMU_CPU clock domain are put together into a
new composite clock type called the cpu clock. This clock type requires
configuration data that will be atomically programmed in the multiple
clock blocks encapsulated within the cpu clock type when the parent clock
frequency is changed. This configuration data is held in the clock controller
node. Update clock binding documentation about this configuration data format
for Samsung Exynos4 and Exynos5 platforms.

Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: <devicetree@vger.kernel.org>
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
---
.../devicetree/bindings/clock/exynos4-clock.txt | 37 ++++++++++++++++++++
.../devicetree/bindings/clock/exynos5250-clock.txt | 36 +++++++++++++++++++
2 files changed, 73 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/exynos4-clock.txt b/Documentation/devicetree/bindings/clock/exynos4-clock.txt
index f5a5b19..0934e02 100644
--- a/Documentation/devicetree/bindings/clock/exynos4-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos4-clock.txt
@@ -15,6 +15,35 @@ 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
+
+ - for Exynos4210 and Exynos4212 based platforms:
+ cell #1: arm clock parent frequency
+ cell #2 ~ cell 9#: value of clock divider in the following order
+ corem0_ratio, corem1_ratio, periph_ratio, atb_ratio,
+ pclk_dbg_ratio, apll_ratio, copy_ratio, hpm_ratio.
+
+ - for Exynos4412 based platforms:
+ cell #1: expected arm clock parent frequency
+ cell #2 ~ cell #10: value of clock divider in the following order
+ corem0_ratio, corem1_ratio, periph_ratio, atb_ratio,
+ pclk_dbg_ratio, apll_ratio, copy_ratio, hpm_ratio, cores_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.
+
+ - for Exynos4210 and Exynos4212: the value should be 9.
+ - for Exynos4412: the value should be 10.
+
Each clock is assigned an identifier and client nodes can use this identifier
to specify the clock which they consume.

@@ -28,6 +57,14 @@ Example 1: An example of a clock controller node is listed below.
compatible = "samsung,exynos4210-clock";
reg = <0x10030000 0x20000>;
#clock-cells = <1>;
+
+ samsung,armclk-cells = <9>;
+ samsung,armclk-divider-table = <1200000 3 7 3 4 1 7 5 0>,
+ <1000000 3 7 3 4 1 7 4 0>,
+ < 800000 3 7 3 3 1 7 3 0>,
+ < 500000 3 7 3 3 1 7 3 0>,
+ < 400000 3 7 3 3 1 7 3 0>,
+ < 200000 1 3 1 1 1 0 3 0>;
};

Example 2: UART controller node that consumes the clock generated by the clock
diff --git a/Documentation/devicetree/bindings/clock/exynos5250-clock.txt b/Documentation/devicetree/bindings/clock/exynos5250-clock.txt
index 536eacd..3d63d09 100644
--- a/Documentation/devicetree/bindings/clock/exynos5250-clock.txt
+++ b/Documentation/devicetree/bindings/clock/exynos5250-clock.txt
@@ -13,6 +13,24 @@ 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 #9: value of clock divider in the following order
+ cpud_ratio, acp_ratio, periph_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 should be 9.
+
Each clock is assigned an identifier and client nodes can use this identifier
to specify the clock which they consume.

@@ -26,6 +44,24 @@ Example 1: An example of a clock controller node is listed below.
compatible = "samsung,exynos5250-clock";
reg = <0x10010000 0x30000>;
#clock-cells = <1>;
+
+ samsung,armclk-cells = <9>;
+ samsung,armclk-divider-table = <1700000 3 7 7 7 3 5 0 2>,
+ <1600000 3 7 7 7 1 4 0 2>,
+ <1500000 2 7 7 7 1 4 0 2>,
+ <1400000 2 7 7 6 1 4 0 2>,
+ <1300000 2 7 7 6 1 3 0 2>,
+ <1200000 2 7 7 5 1 3 0 2>,
+ <1100000 3 7 7 5 1 3 0 2>,
+ <1000000 1 7 7 4 1 2 0 2>,
+ < 900000 1 7 7 4 1 2 0 2>,
+ < 800000 1 7 7 4 1 2 0 2>,
+ < 700000 1 7 7 3 1 1 0 2>,
+ < 600000 1 7 7 3 1 1 0 2>,
+ < 500000 1 7 7 2 1 1 0 2>,
+ < 400000 1 7 7 2 1 1 0 2>,
+ < 300000 1 7 7 1 1 1 0 2>,
+ < 200000 1 7 7 1 1 1 0 2>;
};

Example 2: UART controller node that consumes the clock generated by the clock
--
1.7.4.4