[PATCH 0/4] syscon: Alter syscon and reboot-mode drivers

[PATCH 0/4] syscon: Alter syscon and reboot-mode drivers

[Sergey.Semin]

From: Serge Semin <fancer.lancer@gmail.com>

A lot of custom functionality can be tuned by means of a syscon-registers
placed in Baikal-T1 CCU memory space (though in documentation they are
called system devices registers). While in most of the case the syscon
registers usage will be distributed between corresponding subsystem drivers
(thanks to pretty much coherent design of the registers fields), there are
some peculiarities we should reflect in the generic syscon code.

First of all seeing there is an map endiannes config acceptable by the syscon
it would be justified to add the corresponding properties declared in the
mfd/syscon.yaml bindings file. Don't really know why this hasn't been done
before.

Then as it's going to be general in the framework of the Baikal-T1 SoC support
integration into the kernel, we suggest to replace the legacy text-based
syscon-reboot-mode dts-bindings file with yaml-based one.

Finally seeing the syscon-reboot-mode devices are mostly used in conjuction
with just syscon-reboot device (in particular Baikal-T1 CCU WDT RCR register is
preserved during any type of reboots) and for several other reasons (see the
commit message for details), we suggest to add the 'regmap' property support
to the syscon-reboot-mode driver. This would eliminate the requirement of
placing the syscon-reboot-mode dts-node in the syscon sub-nodes area.

This patchset is rebased and tested on the mainline Linux kernel 5.6-rc4:
commit 98d54f81e36b ("Linux 5.6-rc4").

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru>
Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Ekaterina Skachko <Ekaterina.Skachko@baikalelectronics.ru>
Cc: Vadim Vlasov <V.Vlasov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Serge Semin (4):
  dt-bindings: syscon: Add syscon endian properties support
  dt-bindings: power: reset: Replace SYSCON reboot-mode legacy bindings
    with YAML-based one
  dt-bindings: power: reset: Add regmap support to the SYSCON
    reboot-mode bindings
  power: reset: syscon-reboot-mode: Add regmap dts-property support

 .../devicetree/bindings/mfd/syscon.yaml       | 14 +++++
 .../power/reset/syscon-reboot-mode.txt        | 35 -----------
 .../power/reset/syscon-reboot-mode.yaml       | 58 +++++++++++++++++++
 drivers/power/reset/syscon-reboot-mode.c      | 11 +++-
 4 files changed, 80 insertions(+), 38 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
 create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml

-- 
2.25.1

Re: [PATCH 0/4] syscon: Alter syscon and reboot-mode drivers

[Lee Jones]

On Fri, 06 Mar 2020, Sergey.Semin@baikalelectronics.ru wrote:

> From: Serge Semin <fancer.lancer@gmail.com>
> 
> A lot of custom functionality can be tuned by means of a syscon-registers
> placed in Baikal-T1 CCU memory space (though in documentation they are
> called system devices registers). While in most of the case the syscon
> registers usage will be distributed between corresponding subsystem drivers
> (thanks to pretty much coherent design of the registers fields), there are
> some peculiarities we should reflect in the generic syscon code.
> 
> First of all seeing there is an map endiannes config acceptable by the syscon
> it would be justified to add the corresponding properties declared in the
> mfd/syscon.yaml bindings file. Don't really know why this hasn't been done
> before.
> 
> Then as it's going to be general in the framework of the Baikal-T1 SoC support
> integration into the kernel, we suggest to replace the legacy text-based
> syscon-reboot-mode dts-bindings file with yaml-based one.
> 
> Finally seeing the syscon-reboot-mode devices are mostly used in conjuction
> with just syscon-reboot device (in particular Baikal-T1 CCU WDT RCR register is
> preserved during any type of reboots) and for several other reasons (see the
> commit message for details), we suggest to add the 'regmap' property support
> to the syscon-reboot-mode driver. This would eliminate the requirement of
> placing the syscon-reboot-mode dts-node in the syscon sub-nodes area.
> 
> This patchset is rebased and tested on the mainline Linux kernel 5.6-rc4:
> commit 98d54f81e36b ("Linux 5.6-rc4").
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru>
> Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
> Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
> Cc: Ekaterina Skachko <Ekaterina.Skachko@baikalelectronics.ru>
> Cc: Vadim Vlasov <V.Vlasov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Sebastian Reichel <sre@kernel.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-pm@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> 
> Serge Semin (4):
>   dt-bindings: syscon: Add syscon endian properties support
>   dt-bindings: power: reset: Replace SYSCON reboot-mode legacy bindings
>     with YAML-based one
>   dt-bindings: power: reset: Add regmap support to the SYSCON
>     reboot-mode bindings
>   power: reset: syscon-reboot-mode: Add regmap dts-property support
> 
>  .../devicetree/bindings/mfd/syscon.yaml       | 14 +++++
>  .../power/reset/syscon-reboot-mode.txt        | 35 -----------
>  .../power/reset/syscon-reboot-mode.yaml       | 58 +++++++++++++++++++
>  drivers/power/reset/syscon-reboot-mode.c      | 11 +++-
>  4 files changed, 80 insertions(+), 38 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
>  create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml

Please re-send this patch --threaded.

As it stands, it's been scattered to the 4 winds throughout my inbox.

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH 0/4] syscon: Alter syscon and reboot-mode drivers

[Sergey Semin]

On Mon, Mar 09, 2020 at 07:13:13AM +0000, Lee Jones wrote:
> On Fri, 06 Mar 2020, Sergey.Semin@baikalelectronics.ru wrote:
> 
> > From: Serge Semin <fancer.lancer@gmail.com>
> > 
> > A lot of custom functionality can be tuned by means of a syscon-registers
> > placed in Baikal-T1 CCU memory space (though in documentation they are
> > called system devices registers). While in most of the case the syscon
> > registers usage will be distributed between corresponding subsystem drivers
> > (thanks to pretty much coherent design of the registers fields), there are
> > some peculiarities we should reflect in the generic syscon code.
> > 
> > First of all seeing there is an map endiannes config acceptable by the syscon
> > it would be justified to add the corresponding properties declared in the
> > mfd/syscon.yaml bindings file. Don't really know why this hasn't been done
> > before.
> > 
> > Then as it's going to be general in the framework of the Baikal-T1 SoC support
> > integration into the kernel, we suggest to replace the legacy text-based
> > syscon-reboot-mode dts-bindings file with yaml-based one.
> > 
> > Finally seeing the syscon-reboot-mode devices are mostly used in conjuction
> > with just syscon-reboot device (in particular Baikal-T1 CCU WDT RCR register is
> > preserved during any type of reboots) and for several other reasons (see the
> > commit message for details), we suggest to add the 'regmap' property support
> > to the syscon-reboot-mode driver. This would eliminate the requirement of
> > placing the syscon-reboot-mode dts-node in the syscon sub-nodes area.
> > 
> > This patchset is rebased and tested on the mainline Linux kernel 5.6-rc4:
> > commit 98d54f81e36b ("Linux 5.6-rc4").
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru>
> > Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
> > Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
> > Cc: Ekaterina Skachko <Ekaterina.Skachko@baikalelectronics.ru>
> > Cc: Vadim Vlasov <V.Vlasov@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Lee Jones <lee.jones@linaro.org>
> > Cc: Sebastian Reichel <sre@kernel.org>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: devicetree@vger.kernel.org
> > Cc: linux-pm@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > 
> > Serge Semin (4):
> >   dt-bindings: syscon: Add syscon endian properties support
> >   dt-bindings: power: reset: Replace SYSCON reboot-mode legacy bindings
> >     with YAML-based one
> >   dt-bindings: power: reset: Add regmap support to the SYSCON
> >     reboot-mode bindings
> >   power: reset: syscon-reboot-mode: Add regmap dts-property support
> > 
> >  .../devicetree/bindings/mfd/syscon.yaml       | 14 +++++
> >  .../power/reset/syscon-reboot-mode.txt        | 35 -----------
> >  .../power/reset/syscon-reboot-mode.yaml       | 58 +++++++++++++++++++
> >  drivers/power/reset/syscon-reboot-mode.c      | 11 +++-
> >  4 files changed, 80 insertions(+), 38 deletions(-)
> >  delete mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> >  create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
> 
> Please re-send this patch --threaded.
> 
> As it stands, it's been scattered to the 4 winds throughout my inbox.
> 

Hello Lee,

Of course I've sent the patchset with 'thread=true' config set. It appears our
corporate email server changes the Message-Id field of messages passing through
it. Due to that the emails threading gets to be broken. I'll resubmit the
properly structured v2 patchset as soon as our system administrator fixes
the problem. Sorry for the inconvenience caused by it.

Regards
-Sergey


> -- 
> Lee Jones [李琼斯]
> Linaro Services Technical Lead
> Linaro.org │ Open source software for ARM SoCs
> Follow Linaro: Facebook | Twitter | Blog

[PATCH v2 0/3] syscon: Alter syscon and reboot drivers

[Serge Semin]

This is a small patchset about tuning the syscon infrastructure a bit.
As it's going to be general in the framework of the Baikal-T1 SoC support
integration into the kernel, we suggest to replace the legacy text-based
syscon-reboot-mode dts-bindings file with yaml-based one. Then seeing a
syscon reboot block is normally expected to be a part of a system
controller and based on the discussion
https://lore.kernel.org/linux-pm/20200306130402.1F4F0803079F@mail.baikalelectronics.ru/
we decided to alter the syscon reboot driver so one would also try to fetch
the syscon registers map from a parental DT node. regmap property is left
supported although it's marked as deprecated from now.

This patchset is rebased and tested on the mainline Linux kernel 5.7-rc4:
0e698dfa2822 ("Linux 5.7-rc4")
tag: v5.7-rc4

Changelog v2:
- Add Sebastian' Acked-by tag to patch 1.
- Use a shorter summary describing the bindings modification patches.
- Our corporate email server doesn't change Message-Id anymore, so the patchset
  is resubmitted being in the cover-letter-threaded format.
- Discard patch with syscon "-endian" property support. As Rob said It shall be
  in the common dt-schema.
- Replace patches of adding a regmap property support to the syscon-reboot-mode
  with patches making syscon-reboot a sub-node of a system controller node.
- Mark regmap property as deprecated from now.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru>
Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Ekaterina Skachko <Ekaterina.Skachko@baikalelectronics.ru>
Cc: Vadim Vlasov <V.Vlasov@baikalelectronics.ru>
Cc: Alexey Kolotnikov <Alexey.Kolotnikov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Allison Randal <allison@lohutok.net>
Cc: Richard Fontana <rfontana@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Serge Semin (3):
  dt-bindings: power: reset: Convert syscon-reboot-mode to DT schema
  dt-bindings: power: reset: Unrequire regmap property in syscon-reboot
    node
  power: reset: syscon-reboot: Add parental syscon support

 .../power/reset/syscon-reboot-mode.txt        | 35 ------------
 .../power/reset/syscon-reboot-mode.yaml       | 55 +++++++++++++++++++
 .../bindings/power/reset/syscon-reboot.yaml   | 15 +++--
 drivers/power/reset/syscon-reboot.c           |  7 ++-
 4 files changed, 70 insertions(+), 42 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
 create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml

-- 
2.25.1

[PATCH v2 1/3] dt-bindings: power: reset: Convert syscon-reboot-mode to DT schema

[Serge Semin]

Modern device tree bindings are supposed to be created as YAML-files
in accordance with dt-schema. This commit replaces SYSCON reboot-mode
legacy bare text bindings with YAML file. As before the bindings file
states that the corresponding dts node is supposed to be compatible
"syscon-reboot-mode" device and necessarily have an offset property
to determine which register from the regmap is supposed to keep the
mode on reboot.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Allison Randal <allison@lohutok.net>
Cc: Richard Fontana <rfontana@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@vger.kernel.org
---
 .../power/reset/syscon-reboot-mode.txt        | 35 ------------
 .../power/reset/syscon-reboot-mode.yaml       | 55 +++++++++++++++++++
 2 files changed, 55 insertions(+), 35 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
 create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml

diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
deleted file mode 100644
index f7ce1d8af04a..000000000000
--- a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
+++ /dev/null
@@ -1,35 +0,0 @@
-SYSCON reboot mode driver
-
-This driver gets reboot mode magic value form reboot-mode driver
-and stores it in a SYSCON mapped register. Then the bootloader
-can read it and take different action according to the magic
-value stored.
-
-This DT node should be represented as a sub-node of a "syscon", "simple-mfd"
-node.
-
-Required properties:
-- compatible: should be "syscon-reboot-mode"
-- offset: offset in the register map for the storage register (in bytes)
-
-Optional property:
-- mask: bits mask of the bits in the register to store the reboot mode magic value,
-  default set to 0xffffffff if missing.
-
-The rest of the properties should follow the generic reboot-mode description
-found in reboot-mode.txt
-
-Example:
-	pmu: pmu@20004000 {
-		compatible = "rockchip,rk3066-pmu", "syscon", "simple-mfd";
-		reg = <0x20004000 0x100>;
-
-		reboot-mode {
-			compatible = "syscon-reboot-mode";
-			offset = <0x40>;
-			mode-normal = <BOOT_NORMAL>;
-			mode-recovery = <BOOT_RECOVERY>;
-			mode-bootloader = <BOOT_FASTBOOT>;
-			mode-loader = <BOOT_BL_DOWNLOAD>;
-		};
-	};
diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
new file mode 100644
index 000000000000..9b1ffceefe3d
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/reset/syscon-reboot-mode.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic SYSCON reboot mode driver
+
+maintainers:
+  - Sebastian Reichel <sre@kernel.org>
+
+description: |
+  This driver gets reboot mode magic value from reboot-mode driver
+  and stores it in a SYSCON mapped register. Then the bootloader
+  can read it and take different action according to the magic
+  value stored. The SYSCON mapped register is retrieved from the
+  parental dt-node plus the offset. So the SYSCON reboot-mode node
+  should be represented as a sub-node of a "syscon", "simple-mfd" node.
+
+properties:
+  compatible:
+    const: syscon-reboot-mode
+
+  mask:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Update only the register bits defined by the mask (32 bit)
+
+  offset:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Offset in the register map for the mode register (in bytes)
+
+patternProperties:
+  "^mode-.+":
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Vendor-specific mode value written to the mode register
+
+additionalProperties: false
+
+required:
+  - compatible
+  - offset
+
+examples:
+  - |
+    #include <dt-bindings/soc/rockchip,boot-mode.h>
+
+    reboot-mode {
+      compatible = "syscon-reboot-mode";
+      offset = <0x40>;
+      mode-normal = <BOOT_NORMAL>;
+      mode-recovery = <BOOT_RECOVERY>;
+      mode-bootloader = <BOOT_FASTBOOT>;
+      mode-loader = <BOOT_BL_DOWNLOAD>;
+    };
+...
-- 
2.25.1

[PATCH v2 2/3] dt-bindings: power: reset: Unrequire regmap property in syscon-reboot node

[Serge Semin]

Since normally syscon-reboot block is supposed to be a part of a system
controller, lets mark the regmap property as deprecated and recommend the
syscon-reboot node to be a sub-node of SYSCON.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Allison Randal <allison@lohutok.net>
Cc: Richard Fontana <rfontana@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@vger.kernel.org

---

Changelog v2:
- This is a new patch created as a result of the discussion:
  https://lore.kernel.org/linux-pm/20200306130402.1F4F0803079F@mail.baikalelectronics.ru/
---
 .../bindings/power/reset/syscon-reboot.yaml       | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot.yaml b/Documentation/devicetree/bindings/power/reset/syscon-reboot.yaml
index b80772cb9f06..da2509724812 100644
--- a/Documentation/devicetree/bindings/power/reset/syscon-reboot.yaml
+++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot.yaml
@@ -12,9 +12,12 @@ maintainers:
 description: |+
   This is a generic reset driver using syscon to map the reset register.
   The reset is generally performed with a write to the reset register
-  defined by the register map pointed by syscon reference plus the offset
-  with the value and mask defined in the reboot node.
-  Default will be little endian mode, 32 bit access only.
+  defined by the SYSCON register map base plus the offset with the value and
+  mask defined in the reboot node. Default will be little endian mode, 32 bit
+  access only. The SYSCON registers map is normally retrieved from the
+  parental dt-node. So the SYSCON reboot node should be represented as a
+  sub-node of a "syscon", "simple-mfd" node. Though the regmap property
+  pointing to the system controller node is also supported.
 
 properties:
   compatible:
@@ -30,7 +33,10 @@ properties:
 
   regmap:
     $ref: /schemas/types.yaml#/definitions/phandle
-    description: Phandle to the register map node.
+    deprecated: true
+    description: |
+      Phandle to the register map node. This property is deprecated in favor of
+      the syscon-reboot node been a child of a system controller node.
 
   value:
     $ref: /schemas/types.yaml#/definitions/uint32
@@ -38,7 +44,6 @@ properties:
 
 required:
   - compatible
-  - regmap
   - offset
 
 additionalProperties: false
-- 
2.25.1

[PATCH v2 3/3] power: reset: syscon-reboot: Add parental syscon support

[Serge Semin]

Since normally syscon-reboot block is supposed to be a part of a system
controller, lets look for the syscon regmap in a parental DT node if
regmap property isn't specified. DT binding from now considers the regmap
property as deprecated.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org

---

Changelog v2:
- This is a new patch created as a result of the discussion:
  https://lore.kernel.org/linux-pm/20200306130402.1F4F0803079F@mail.baikalelectronics.ru/
---
 drivers/power/reset/syscon-reboot.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c
index 62fbba0df971..510e363381ca 100644
--- a/drivers/power/reset/syscon-reboot.c
+++ b/drivers/power/reset/syscon-reboot.c
@@ -51,8 +51,11 @@ static int syscon_reboot_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
-	if (IS_ERR(ctx->map))
-		return PTR_ERR(ctx->map);
+	if (IS_ERR(ctx->map)) {
+		ctx->map = syscon_node_to_regmap(dev->parent->of_node);
+		if (IS_ERR(ctx->map))
+			return PTR_ERR(ctx->map);
+	}
 
 	if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset))
 		return -EINVAL;
-- 
2.25.1

Re: [PATCH v2 1/3] dt-bindings: power: reset: Convert syscon-reboot-mode to DT schema

[Sebastian Reichel]

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Hi,

On Fri, May 08, 2020 at 02:38:44AM +0300, Serge Semin wrote:
> Modern device tree bindings are supposed to be created as YAML-files
> in accordance with dt-schema. This commit replaces SYSCON reboot-mode
> legacy bare text bindings with YAML file. As before the bindings file
> states that the corresponding dts node is supposed to be compatible
> "syscon-reboot-mode" device and necessarily have an offset property
> to determine which register from the regmap is supposed to keep the
> mode on reboot.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Allison Randal <allison@lohutok.net>
> Cc: Richard Fontana <rfontana@redhat.com>
> Cc: Kate Stewart <kstewart@linuxfoundation.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: linux-mips@vger.kernel.org
> ---

Thanks, I queued this patch to power-supply's for-next branch. For the other
two patches I will wait for Rob's feedback.

-- Sebastian

>  .../power/reset/syscon-reboot-mode.txt        | 35 ------------
>  .../power/reset/syscon-reboot-mode.yaml       | 55 +++++++++++++++++++
>  2 files changed, 55 insertions(+), 35 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
>  create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
> 
> diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> deleted file mode 100644
> index f7ce1d8af04a..000000000000
> --- a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> +++ /dev/null
> @@ -1,35 +0,0 @@
> -SYSCON reboot mode driver
> -
> -This driver gets reboot mode magic value form reboot-mode driver
> -and stores it in a SYSCON mapped register. Then the bootloader
> -can read it and take different action according to the magic
> -value stored.
> -
> -This DT node should be represented as a sub-node of a "syscon", "simple-mfd"
> -node.
> -
> -Required properties:
> -- compatible: should be "syscon-reboot-mode"
> -- offset: offset in the register map for the storage register (in bytes)
> -
> -Optional property:
> -- mask: bits mask of the bits in the register to store the reboot mode magic value,
> -  default set to 0xffffffff if missing.
> -
> -The rest of the properties should follow the generic reboot-mode description
> -found in reboot-mode.txt
> -
> -Example:
> -	pmu: pmu@20004000 {
> -		compatible = "rockchip,rk3066-pmu", "syscon", "simple-mfd";
> -		reg = <0x20004000 0x100>;
> -
> -		reboot-mode {
> -			compatible = "syscon-reboot-mode";
> -			offset = <0x40>;
> -			mode-normal = <BOOT_NORMAL>;
> -			mode-recovery = <BOOT_RECOVERY>;
> -			mode-bootloader = <BOOT_FASTBOOT>;
> -			mode-loader = <BOOT_BL_DOWNLOAD>;
> -		};
> -	};
> diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
> new file mode 100644
> index 000000000000..9b1ffceefe3d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
> @@ -0,0 +1,55 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/power/reset/syscon-reboot-mode.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Generic SYSCON reboot mode driver
> +
> +maintainers:
> +  - Sebastian Reichel <sre@kernel.org>
> +
> +description: |
> +  This driver gets reboot mode magic value from reboot-mode driver
> +  and stores it in a SYSCON mapped register. Then the bootloader
> +  can read it and take different action according to the magic
> +  value stored. The SYSCON mapped register is retrieved from the
> +  parental dt-node plus the offset. So the SYSCON reboot-mode node
> +  should be represented as a sub-node of a "syscon", "simple-mfd" node.
> +
> +properties:
> +  compatible:
> +    const: syscon-reboot-mode
> +
> +  mask:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: Update only the register bits defined by the mask (32 bit)
> +
> +  offset:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: Offset in the register map for the mode register (in bytes)
> +
> +patternProperties:
> +  "^mode-.+":
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: Vendor-specific mode value written to the mode register
> +
> +additionalProperties: false
> +
> +required:
> +  - compatible
> +  - offset
> +
> +examples:
> +  - |
> +    #include <dt-bindings/soc/rockchip,boot-mode.h>
> +
> +    reboot-mode {
> +      compatible = "syscon-reboot-mode";
> +      offset = <0x40>;
> +      mode-normal = <BOOT_NORMAL>;
> +      mode-recovery = <BOOT_RECOVERY>;
> +      mode-bootloader = <BOOT_FASTBOOT>;
> +      mode-loader = <BOOT_BL_DOWNLOAD>;
> +    };
> +...
> -- 
> 2.25.1
> 

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Re: [PATCH v2 1/3] dt-bindings: power: reset: Convert syscon-reboot-mode to DT schema

[Serge Semin]

Hello

On Sat, May 09, 2020 at 02:30:45AM +0200, Sebastian Reichel wrote:
> Hi,
> 
> On Fri, May 08, 2020 at 02:38:44AM +0300, Serge Semin wrote:
> > Modern device tree bindings are supposed to be created as YAML-files
> > in accordance with dt-schema. This commit replaces SYSCON reboot-mode
> > legacy bare text bindings with YAML file. As before the bindings file
> > states that the corresponding dts node is supposed to be compatible
> > "syscon-reboot-mode" device and necessarily have an offset property
> > to determine which register from the regmap is supposed to keep the
> > mode on reboot.
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Allison Randal <allison@lohutok.net>
> > Cc: Richard Fontana <rfontana@redhat.com>
> > Cc: Kate Stewart <kstewart@linuxfoundation.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: linux-mips@vger.kernel.org
> > ---
> 
> Thanks, I queued this patch to power-supply's for-next branch. For the other
> two patches I will wait for Rob's feedback.

Great! Thanks. The rest of the patches shall also be fine since we discussed
the changes with Rob in comments to v1. Anyway lets wait for his response.

-Sergey

> 
> -- Sebastian
> 
> >  .../power/reset/syscon-reboot-mode.txt        | 35 ------------
> >  .../power/reset/syscon-reboot-mode.yaml       | 55 +++++++++++++++++++
> >  2 files changed, 55 insertions(+), 35 deletions(-)
> >  delete mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> >  create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> > deleted file mode 100644
> > index f7ce1d8af04a..000000000000
> > --- a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.txt
> > +++ /dev/null
> > @@ -1,35 +0,0 @@
> > -SYSCON reboot mode driver
> > -
> > -This driver gets reboot mode magic value form reboot-mode driver
> > -and stores it in a SYSCON mapped register. Then the bootloader
> > -can read it and take different action according to the magic
> > -value stored.
> > -
> > -This DT node should be represented as a sub-node of a "syscon", "simple-mfd"
> > -node.
> > -
> > -Required properties:
> > -- compatible: should be "syscon-reboot-mode"
> > -- offset: offset in the register map for the storage register (in bytes)
> > -
> > -Optional property:
> > -- mask: bits mask of the bits in the register to store the reboot mode magic value,
> > -  default set to 0xffffffff if missing.
> > -
> > -The rest of the properties should follow the generic reboot-mode description
> > -found in reboot-mode.txt
> > -
> > -Example:
> > -	pmu: pmu@20004000 {
> > -		compatible = "rockchip,rk3066-pmu", "syscon", "simple-mfd";
> > -		reg = <0x20004000 0x100>;
> > -
> > -		reboot-mode {
> > -			compatible = "syscon-reboot-mode";
> > -			offset = <0x40>;
> > -			mode-normal = <BOOT_NORMAL>;
> > -			mode-recovery = <BOOT_RECOVERY>;
> > -			mode-bootloader = <BOOT_FASTBOOT>;
> > -			mode-loader = <BOOT_BL_DOWNLOAD>;
> > -		};
> > -	};
> > diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
> > new file mode 100644
> > index 000000000000..9b1ffceefe3d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot-mode.yaml
> > @@ -0,0 +1,55 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/power/reset/syscon-reboot-mode.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Generic SYSCON reboot mode driver
> > +
> > +maintainers:
> > +  - Sebastian Reichel <sre@kernel.org>
> > +
> > +description: |
> > +  This driver gets reboot mode magic value from reboot-mode driver
> > +  and stores it in a SYSCON mapped register. Then the bootloader
> > +  can read it and take different action according to the magic
> > +  value stored. The SYSCON mapped register is retrieved from the
> > +  parental dt-node plus the offset. So the SYSCON reboot-mode node
> > +  should be represented as a sub-node of a "syscon", "simple-mfd" node.
> > +
> > +properties:
> > +  compatible:
> > +    const: syscon-reboot-mode
> > +
> > +  mask:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description: Update only the register bits defined by the mask (32 bit)
> > +
> > +  offset:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description: Offset in the register map for the mode register (in bytes)
> > +
> > +patternProperties:
> > +  "^mode-.+":
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description: Vendor-specific mode value written to the mode register
> > +
> > +additionalProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - offset
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/soc/rockchip,boot-mode.h>
> > +
> > +    reboot-mode {
> > +      compatible = "syscon-reboot-mode";
> > +      offset = <0x40>;
> > +      mode-normal = <BOOT_NORMAL>;
> > +      mode-recovery = <BOOT_RECOVERY>;
> > +      mode-bootloader = <BOOT_FASTBOOT>;
> > +      mode-loader = <BOOT_BL_DOWNLOAD>;
> > +    };
> > +...
> > -- 
> > 2.25.1
> > 

Re: [PATCH v2 2/3] dt-bindings: power: reset: Unrequire regmap property in syscon-reboot node

[Rob Herring]

On Fri, 8 May 2020 02:38:45 +0300, Serge Semin wrote:
> Since normally syscon-reboot block is supposed to be a part of a system
> controller, lets mark the regmap property as deprecated and recommend the
> syscon-reboot node to be a sub-node of SYSCON.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Allison Randal <allison@lohutok.net>
> Cc: Richard Fontana <rfontana@redhat.com>
> Cc: Kate Stewart <kstewart@linuxfoundation.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: linux-mips@vger.kernel.org
> 
> ---
> 
> Changelog v2:
> - This is a new patch created as a result of the discussion:
>   https://lore.kernel.org/linux-pm/20200306130402.1F4F0803079F@mail.baikalelectronics.ru/
> ---
>  .../bindings/power/reset/syscon-reboot.yaml       | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v2 2/3] dt-bindings: power: reset: Unrequire regmap property in syscon-reboot node

[Serge Semin]

On Thu, May 14, 2020 at 10:14:49PM -0500, Rob Herring wrote:
> On Fri, 8 May 2020 02:38:45 +0300, Serge Semin wrote:
> > Since normally syscon-reboot block is supposed to be a part of a system
> > controller, lets mark the regmap property as deprecated and recommend the
> > syscon-reboot node to be a sub-node of SYSCON.
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Allison Randal <allison@lohutok.net>
> > Cc: Richard Fontana <rfontana@redhat.com>
> > Cc: Kate Stewart <kstewart@linuxfoundation.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: linux-mips@vger.kernel.org
> > 
> > ---
> > 
> > Changelog v2:
> > - This is a new patch created as a result of the discussion:
> >   https://lore.kernel.org/linux-pm/20200306130402.1F4F0803079F@mail.baikalelectronics.ru/
> > ---
> >  .../bindings/power/reset/syscon-reboot.yaml       | 15 ++++++++++-----
> >  1 file changed, 10 insertions(+), 5 deletions(-)
> > 
> 
> Reviewed-by: Rob Herring <robh@kernel.org>

Great. Thanks!

Sebastian, Rob is ok with the change. Could you take a look at the next patch?

-Sergey