[PATCH 0/2] irqchip/renesas-intc-irqpin: fallback enhancements

Hi,

this short series aims to improve the fallback compatibility strings
for the renesas-intc-irqpin driver.

Based on v4.9-rc1.

Simon Horman (2):
  irqchip/renesas-intc-irqpin: List fallback compatibility last
  irqchip/renesas-intc-irqpin: Add R-Car Gen1 fallback binding

 .../interrupt-controller/renesas,intc-irqpin.txt   | 44 ++++++++++++----------
 drivers/irqchip/irq-renesas-intc-irqpin.c          |  4 +-
 2 files changed, 27 insertions(+), 21 deletions(-)

-- 
2.7.0.rc3.207.g0ac5344

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 1, Gen 2 and Gen 3. But beyond that its not clear what the
relationship between IP blocks might be. For example, I believe that
r8a7779 is older than r8a7778 but that doesn't imply that the latter is a
descendant of the former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme being adopted for
drivers for Renesas SoCs.

Signed-off-by: Simon Horman <redacted>
---
 .../interrupt-controller/renesas,intc-irqpin.txt   | 44 ++++++++++++----------
 drivers/irqchip/irq-renesas-intc-irqpin.c          |  2 +
 2 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt b/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
index 772c550d3b4b..e5a5251be9f5 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt

@@ -2,13 +2,19 @@ DT bindings for the R-/SH-Mobile irqpin controller
 
 Required properties:
 
-- compatible: has to be "renesas,intc-irqpin-<soctype>", "renesas,intc-irqpin"
-  as fallback.
-  Examples with soctypes are:
+- compatible:
     - "renesas,intc-irqpin-r8a7740" (R-Mobile A1)
     - "renesas,intc-irqpin-r8a7778" (R-Car M1A)
     - "renesas,intc-irqpin-r8a7779" (R-Car H1)
     - "renesas,intc-irqpin-sh73a0" (SH-Mobile AG5)
+    - "renesas,rcar-gen1-intc-irqpin" (generic R-Car Gen1 compatible device)
+    - "renesas,intc-irqpin"         (generic device)
+
+    When compatible with a generic R-Car version, nodes must list the
+    SoC-specific version corresponding to the platform first followed by
+    the generic R-Car version.
+
+    "renesas,intc-irqpin" must be present and last.
 
 - reg: Base address and length of each register bank used by the external
   IRQ pins driven by the interrupt controller hardware module. The base

@@ -39,24 +45,22 @@ Optional properties:
 Example
 -------
 
-	irqpin1: interrupt-controller@e6900004 {
-		compatible = "renesas,intc-irqpin-r8a7740",
+	irqpin0: interrupt-controller@fe78001c {
+		compatible = "renesas,intc-irqpin-r8a7779",
+			     "renesas,rcar-gen1-intc-irqpin",
 			     "renesas,intc-irqpin";
 		#interrupt-cells = <2>;
+		status = "disabled";
 		interrupt-controller;
-		reg = <0xe6900004 4>,
-			<0xe6900014 4>,
-			<0xe6900024 1>,
-			<0xe6900044 1>,
-			<0xe6900064 1>;
-		interrupts = <0 149 IRQ_TYPE_LEVEL_HIGH
-			      0 149 IRQ_TYPE_LEVEL_HIGH
-			      0 149 IRQ_TYPE_LEVEL_HIGH
-			      0 149 IRQ_TYPE_LEVEL_HIGH
-			      0 149 IRQ_TYPE_LEVEL_HIGH
-			      0 149 IRQ_TYPE_LEVEL_HIGH
-			      0 149 IRQ_TYPE_LEVEL_HIGH
-			      0 149 IRQ_TYPE_LEVEL_HIGH>;
-		clocks = <&mstp2_clks R8A7740_CLK_INTCA>;
-		power-domains = <&pd_a4s>;
+		reg = <0xfe78001c 4>,
+			<0xfe780010 4>,
+			<0xfe780024 4>,
+			<0xfe780044 4>,
+			<0xfe780064 4>,
+			<0xfe780000 4>;
+		interrupts = <GIC_SPI 27 IRQ_TYPE_LEVEL_HIGH
+			      GIC_SPI 28 IRQ_TYPE_LEVEL_HIGH
+			      GIC_SPI 29 IRQ_TYPE_LEVEL_HIGH
+			      GIC_SPI 30 IRQ_TYPE_LEVEL_HIGH>;
+		sense-bitfield-width = <2>;
 	};

diff --git a/drivers/irqchip/irq-renesas-intc-irqpin.c b/drivers/irqchip/irq-renesas-intc-irqpin.c
index 5fe1207a079c..70095b61a90a 100644
--- a/drivers/irqchip/irq-renesas-intc-irqpin.c
+++ b/drivers/irqchip/irq-renesas-intc-irqpin.c

@@ -378,6 +378,8 @@ static const struct of_device_id intc_irqpin_dt_ids[] = {
 	  .data = &intc_irqpin_irlm_r8a777x },
 	{ .compatible = "renesas,intc-irqpin-r8a7779",
 	  .data = &intc_irqpin_irlm_r8a777x },
+	{ .compatible = "renesas,rcar-gen1-intc-irqpin",
+	  .data = &intc_irqpin_irlm_r8a777x },
 	{ .compatible = "renesas,intc-irqpin-r8a7740",
 	  .data = &intc_irqpin_rmobile },
 	{ .compatible = "renesas,intc-irqpin-sh73a0",

-- 
2.7.0.rc3.207.g0ac5344

Improve readability by listing the rmobile fallback compatibility string
after the more-specific compatibility strings they provide a fallback for.

This does not effect run-time behaviour as it is the order in the DTB that
determines which compatibility string is used.

Signed-off-by: Simon Horman <redacted>
---
 drivers/irqchip/irq-renesas-intc-irqpin.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-renesas-intc-irqpin.c b/drivers/irqchip/irq-renesas-intc-irqpin.c
index 713177d97c7a..5fe1207a079c 100644
--- a/drivers/irqchip/irq-renesas-intc-irqpin.c
+++ b/drivers/irqchip/irq-renesas-intc-irqpin.c

@@ -374,7 +374,6 @@ static const struct intc_irqpin_config intc_irqpin_rmobile = {
 };
 
 static const struct of_device_id intc_irqpin_dt_ids[] = {
-	{ .compatible = "renesas,intc-irqpin", },
 	{ .compatible = "renesas,intc-irqpin-r8a7778",
 	  .data = &intc_irqpin_irlm_r8a777x },
 	{ .compatible = "renesas,intc-irqpin-r8a7779",

@@ -383,6 +382,7 @@ static const struct of_device_id intc_irqpin_dt_ids[] = {
 	  .data = &intc_irqpin_rmobile },
 	{ .compatible = "renesas,intc-irqpin-sh73a0",
 	  .data = &intc_irqpin_rmobile },
+	{ .compatible = "renesas,intc-irqpin", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);

-- 
2.7.0.rc3.207.g0ac5344

Hi Simon,

On Fri, Dec 9, 2016 at 11:50 AM, Simon Horman
[off-list ref] wrote:

Improve readability by listing the rmobile fallback compatibility string

s/rmobile/generic/

BTW, I'm wondering what's the added value of keeping the generic
"renesas,intc-irqpin" fallback. There is no user of the pure generic version
only, and all SoC-specific versions are treated slightly different.

        {},
 };
 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Hi Simon,

On Fri, Dec 9, 2016 at 11:50 AM, Simon Horman
[off-list ref] wrote:

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 1, Gen 2 and Gen 3. But beyond that its not clear what the

it's

Does it make sense to add a new family-specific compatible value to a driver
that's unlikely to receive more users in the future? More recent SoCs use
renesas,irqc.

If the answer is yes, do we want one for SH/R-Mobile too?

And now we have three compatible values to list...

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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On Fri, Dec 09, 2016 at 01:52:20PM +0100, Geert Uytterhoeven wrote:

Hi Simon,

On Fri, Dec 9, 2016 at 11:50 AM, Simon Horman
[off-list ref] wrote:

quoted

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 1, Gen 2 and Gen 3. But beyond that its not clear what the

it's

quoted

relationship between IP blocks might be. For example, I believe that
r8a7779 is older than r8a7778 but that doesn't imply that the latter is a
descendant of the former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme being adopted for
drivers for Renesas SoCs.

Signed-off-by: Simon Horman <horms+renesas-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org>
---
 .../interrupt-controller/renesas,intc-irqpin.txt   | 44 ++++++++++++----------
 drivers/irqchip/irq-renesas-intc-irqpin.c          |  2 +
 2 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt b/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
index 772c550d3b4b..e5a5251be9f5 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt

@@ -2,13 +2,19 @@ DT bindings for the R-/SH-Mobile irqpin controller

 Required properties:

-- compatible: has to be "renesas,intc-irqpin-<soctype>", "renesas,intc-irqpin"
-  as fallback.
-  Examples with soctypes are:
+- compatible:
     - "renesas,intc-irqpin-r8a7740" (R-Mobile A1)
     - "renesas,intc-irqpin-r8a7778" (R-Car M1A)
     - "renesas,intc-irqpin-r8a7779" (R-Car H1)
     - "renesas,intc-irqpin-sh73a0" (SH-Mobile AG5)
+    - "renesas,rcar-gen1-intc-irqpin" (generic R-Car Gen1 compatible device)

Does it make sense to add a new family-specific compatible value to a driver
that's unlikely to receive more users in the future? More recent SoCs use
renesas,irqc.

If that's the case, then no. Please don't go crazy with your generic 
strings. I don't mind them, but I don't know that I'd call it best 
practice.

Rob
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On Mon, Dec 12, 2016 at 12:43:11PM -0600, Rob Herring wrote:

On Fri, Dec 09, 2016 at 01:52:20PM +0100, Geert Uytterhoeven wrote:

quoted

Hi Simon,

On Fri, Dec 9, 2016 at 11:50 AM, Simon Horman
[off-list ref] wrote:

quoted

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 1, Gen 2 and Gen 3. But beyond that its not clear what the

it's

quoted

relationship between IP blocks might be. For example, I believe that
r8a7779 is older than r8a7778 but that doesn't imply that the latter is a
descendant of the former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme being adopted for
drivers for Renesas SoCs.

Signed-off-by: Simon Horman <horms+renesas-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org>
---
 .../interrupt-controller/renesas,intc-irqpin.txt   | 44 ++++++++++++----------
 drivers/irqchip/irq-renesas-intc-irqpin.c          |  2 +
 2 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt b/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
index 772c550d3b4b..e5a5251be9f5 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/renesas,intc-irqpin.txt

@@ -2,13 +2,19 @@ DT bindings for the R-/SH-Mobile irqpin controller

 Required properties:

-- compatible: has to be "renesas,intc-irqpin-<soctype>", "renesas,intc-irqpin"
-  as fallback.
-  Examples with soctypes are:
+- compatible:
     - "renesas,intc-irqpin-r8a7740" (R-Mobile A1)
     - "renesas,intc-irqpin-r8a7778" (R-Car M1A)
     - "renesas,intc-irqpin-r8a7779" (R-Car H1)
     - "renesas,intc-irqpin-sh73a0" (SH-Mobile AG5)
+    - "renesas,rcar-gen1-intc-irqpin" (generic R-Car Gen1 compatible device)

Does it make sense to add a new family-specific compatible value to a driver
that's unlikely to receive more users in the future? More recent SoCs use
renesas,irqc.

If that's the case, then no. Please don't go crazy with your generic 
strings. I don't mind them, but I don't know that I'd call it best 
practice.

Understood. I do not see any new users of this driver on the horizon
and given the above I withdraw this patch.
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