Thread (2 messages) flat view 2 messages, 2 authors, 2011-08-11

Re: [PATCH v11 3/6] flexcan: Fix up fsl-flexcan device tree binding.

From: Grant Likely <hidden>
Date: 2011-08-11 16:53:43
Also in: linux-devicetree, linuxppc-dev

Possibly related (same subject, not in this thread)

On Thu, Aug 11, 2011 at 10:07 AM, Robin Holt [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This patch cleans up the documentation of the device-tree binding for
the Flexcan devices on Freescale's PowerPC and ARM cores. Extra
properties are not used by the driver so we are removing them.

Signed-off-by: Robin Holt <redacted>
To: Marc Kleine-Budde <mkl@pengutronix.de>,
To: Wolfgang Grandegger <redacted>,
To: U Bhaskar-B22300 <redacted>
To: Scott Wood <redacted>
To: Grant Likely <redacted>
To: Kumar Gala <redacted>
Cc: socketcan-core@lists.berlios.de,
Cc: netdev@vger.kernel.org,
Cc: PPC list <redacted>
Cc: devicetree-discuss@lists.ozlabs.org
---
 .../devicetree/bindings/net/can/fsl-flexcan.txt    |   69 ++++---------------
 arch/powerpc/boot/dts/p1010rdb.dts                 |   10 +--
 arch/powerpc/boot/dts/p1010si.dtsi                 |   10 +--
 3 files changed, 21 insertions(+), 68 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
index 1a729f0..c78dcbb 100644
--- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
+++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
@@ -1,61 +1,22 @@
-CAN Device Tree Bindings
-------------------------
-2011 Freescale Semiconductor, Inc.
+Flexcan CAN contoller on Freescale's ARM and PowerPC processors

-fsl,flexcan-v1.0 nodes
------------------------
-In addition to the required compatible-, reg- and interrupt-properties, you can
-also specify which clock source shall be used for the controller.
+Required properties:

-CPI Clock- Can Protocol Interface Clock
-       This CLK_SRC bit of CTRL(control register) selects the clock source to
-       the CAN Protocol Interface(CPI) to be either the peripheral clock
-       (driven by the PLL) or the crystal oscillator clock. The selected clock
-       is the one fed to the prescaler to generate the Serial Clock (Sclock).
-       The PRESDIV field of CTRL(control register) controls a prescaler that
-       generates the Serial Clock (Sclock), whose period defines the
-       time quantum used to compose the CAN waveform.
+- compatible : Should be "fsl,<processor>-flexcan" and "fsl,flexcan"
Don't do this.  "fsl,flexcan" is far too generic.  Be specific to the
soc part number or the ip core implementation version.
-Can Engine Clock Source
-       There are two sources for CAN clock
-       - Platform Clock  It represents the bus clock
-       - Oscillator Clock
+  An implementation should also claim any of the following compatibles
+  that it is fully backwards compatible with:

-       Peripheral Clock (PLL)
-       --------------
-                    |
-                   ---------                 -------------
-                   |       |CPI Clock        | Prescaler |       Sclock
-                   |       |---------------->| (1.. 256) |------------>
-                   ---------                 -------------
-                     |  |
-       --------------  ---------------------CLK_SRC
-       Oscillator Clock
+  - fsl,p1010-flexcan

-- fsl,flexcan-clock-source : CAN Engine Clock Source.This property selects
-                            the peripheral clock. PLL clock is fed to the
-                            prescaler to generate the Serial Clock (Sclock).
-                            Valid values are "oscillator" and "platform"
-                            "oscillator": CAN engine clock source is oscillator clock.
-                            "platform" The CAN engine clock source is the bus clock
-                            (platform clock).
+- reg : Offset and length of the register set for this device
+- interrupts : Interrupt tuple for this device

-- fsl,flexcan-clock-divider : for the reference and system clock, an additional
-                             clock divider can be specified.
-- clock-frequency: frequency required to calculate the bitrate for FlexCAN.
+Example:

-Note:
-       - v1.0 of flexcan-v1.0 represent the IP block version for P1010 SOC.
-       - P1010 does not have oscillator as the Clock Source.So the default
-         Clock Source is platform clock.
-Examples:
-
-       can0@1c000 {
-               compatible = "fsl,flexcan-v1.0";
-               reg = <0x1c000 0x1000>;
-               interrupts = <48 0x2>;
-               interrupt-parent = <&mpic>;
-               fsl,flexcan-clock-source = "platform";
-               fsl,flexcan-clock-divider = <2>;
-               clock-frequency = <fixed by u-boot>;
-       };
+  can@1c000 {
+          compatible = "fsl,p1010-flexcan", "fsl,flexcan";
+          reg = <0x1c000 0x1000>;
+          interrupts = <48 0x2>;
+          interrupt-parent = <&mpic>;
+  };
The diffstat for this patch looks too big because the whitespace has
changed.  Try to restrict whitespace changes so that the patch is
friendly to reviewers.

g.
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