On Mon, 2019-08-05 at 11:48 +0800, Dong Aisheng wrote:

On Sun, Aug 4, 2019 at 11:49 AM Shawn Guo [off-list ref]
wrote:

quoted

On Tue, Jul 16, 2019 at 11:00:55PM +0800, Dong Aisheng wrote:

quoted

There's a few limitations on the original one cell clock binding
(#clock-cells = <1>) that we have to define some SW clock IDs for
device
tree to reference. This may cause troubles if we want to use
common
clock IDs for multi platforms support when the clock of those
platforms
are mostly the same.
e.g. Current clock IDs name are defined with SS prefix.

However the device may reside in different SS across CPUs, that
means the
SS prefix may not valid anymore for a new SoC. Furthermore, the
device
availability of those clocks may also vary a bit.

For such situation, we want to eliminate the using of SW Clock
IDs and
change to use a more close to HW one instead.
For SCU clocks usage, only two params required: Resource id +
Clock Type.

If this is how SCU firmware addresses the clock, I agree that it's
worth
witching to this new bindings, which describes the hardware (SCU
firmware in this case) better, IMO.

quoted

Both parameters are platform independent. So we could use two
cells binding
to pass those parameters,

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
ChangeLog:
v2->v3:
 * Changed to two cells binding and register all clocks in driver
   instead of parse from device tree.
v1->v2:
 * changed to one cell binding inspired by arm,scpi.txt
   Documentation/devicetree/bindings/arm/arm,scpi.txt
   Resource ID is encoded in 'reg' property.
   Clock type is encoded in generic clock-indices property.
   Then we don't have to search all the DT nodes to fetch
   those two value to construct clocks which is relatively
   low efficiency.
 * Add required power-domain property as well.
---
 .../devicetree/bindings/arm/freescale/fsl,scu.txt       | 12
+++++++-----
 include/dt-bindings/firmware/imx/rsrc.h                 | 17
+++++++++++++++++
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git
a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
index 5d7dbab..351d335 100644

--- a/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt
+++ b/Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt

@@ -89,7 +89,10 @@ Required properties:
                        "fsl,imx8qm-clock"
                        "fsl,imx8qxp-clock"
                      followed by "fsl,scu-clk"
-- #clock-cells:              Should be 1. Contains the Clock ID

value.
+- #clock-cells:              Should be either
+                     2: Contains the Resource and Clock ID
value.
+                     or
+                     1: Contains the Clock ID value.
(DEPRECATED)
 - clocks:            List of clock specifiers, must contain an
entry for
                      each required entry in clock-names
 - clock-names:               Should include entries
"xtal_32KHz", "xtal_24MHz"

@@ -162,7 +165,7 @@ firmware {

              clk: clk {
                      compatible = "fsl,imx8qxp-clk", "fsl,scu-

clk";
-                     #clock-cells = <1>;
+                     #clock-cells = <2>;
              };

              iomuxc {

@@ -192,8 +195,7 @@ serial@5a060000 {
      ...
      pinctrl-names = "default";
      pinctrl-0 = <&pinctrl_lpuart0>;
-     clocks = <&clk IMX8QXP_UART0_CLK>,
-              <&clk IMX8QXP_UART0_IPG_CLK>;
-     clock-names = "per", "ipg";
+     clocks = <&uart0_clk IMX_SC_R_UART_0 IMX_SC_PM_CLK_PER>;
+     clock-names = "ipg";
      power-domains = <&pd IMX_SC_R_UART_0>;
 };

diff --git a/include/dt-bindings/firmware/imx/rsrc.h

b/include/dt-bindings/firmware/imx/rsrc.h
index 4e61f64..fbeaca7 100644

--- a/include/dt-bindings/firmware/imx/rsrc.h
+++ b/include/dt-bindings/firmware/imx/rsrc.h

@@ -547,4 +547,21 @@
 #define IMX_SC_R_ATTESTATION         545
 #define IMX_SC_R_LAST                        546

+/*
+ * Defines for SC PM CLK
+ */
+#define IMX_SC_PM_CLK_SLV_BUS                0       /* Slave

bus clock */
+#define IMX_SC_PM_CLK_MST_BUS                1       /* Master
bus clock */
+#define IMX_SC_PM_CLK_PER            2       /* Peripheral clock
*/
+#define IMX_SC_PM_CLK_PHY            3       /* Phy clock */
+#define IMX_SC_PM_CLK_MISC           4       /* Misc clock */

This is for typical device resource.

quoted

quoted

+#define IMX_SC_PM_CLK_MISC0          0       /* Misc 0 clock */
+#define IMX_SC_PM_CLK_MISC1          1       /* Misc 1 clock */
+#define IMX_SC_PM_CLK_MISC2          2       /* Misc 2 clock */
+#define IMX_SC_PM_CLK_MISC3          3       /* Misc 3 clock */
+#define IMX_SC_PM_CLK_MISC4          4       /* Misc 4 clock */

This is for some special clock types which do not belong to above
normal clock types.
Used very rare in SCU firmware.
e.g.
enet0_mac0_rxclk SC_R_ENE T_0 / SC_PM_CL K_MISC0

quoted

quoted

+#define IMX_SC_PM_CLK_CPU            2       /* CPU clock */
+#define IMX_SC_PM_CLK_PLL            4       /* PLL */
+#define IMX_SC_PM_CLK_BYPASS         4       /* Bypass clock */

They're for specific clock types for CPU/PLL/BYPASS only.

Hi Aisheng,

Yes, please separate this types of clocks in their own sections with
proper description.

quoted

It seems that there are several sets of clock type which apply to
different resources/devices?  If so, can you separate them a bit
with
some comments to make the list easier for readers?

So, please send v4 with all comments fixed. I can help with testing.
I am also intrested in seeing this get in!

thanks,
Daniel.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel