[PATCH v4 0/4] nvmem: qfprom: Patches for fuse blowing on Qualcomm SoCs

[PATCH v4 0/4] nvmem: qfprom: Patches for fuse blowing on Qualcomm SoCs

[Douglas Anderson]

This series enables blowing of fuses on Qualcomm SoCs by extending the
existing qfprom driver with write support.

A few notes:
- Though I don't have any firsthand knowledge of it, it's my
  understanding that these changes could be used on any Qualcomm SoC.
  However, it's likely not very useful on most boards because the
  bootloader protects against this.  Thus the write support here is
  likely only useful with a cooperating bootloader.
- Blowing fuses is truly a one-way process.  If you mess around with
  this and do something wrong you could irreparably brick your chip.
  You have been warned.

Versions 1 and 2 of this series were posted by Ravi Kumar Bokka.  I
posted version 3 containing my changes / fixups with his consent.  I
have left authorship as Ravi but added my own Signed-off-by.

Version 4 is a minor spin over version 3.

Changes in v4:
- Maintainer now listed as Srinivas.
- Example under "soc" to get #address-cells and #size-cells.
- Clock name is "core", not "sec".
- Example under "soc" to get #address-cells and #size-cells.
- Only get clock/regulator if all address ranges are provided.
- Don't use optional version of clk_get now.
- Clock name is "core", not "sec".
- Cleaned up error message if couldn't get clock.
- Fixed up minor version mask.
- Use GENMASK to generate masks.
- Clock name is "core", not "sec".

Changes in v3:
- Split conversion to yaml into separate patch new in v3.
- Use 'const' for compatible instead of a 1-entry enum.
- Changed filename to match compatible string.
- Add #address-cells and #size-cells to list of properties.
- Fixed up example.
- Add an extra reg range (at 0x6000 offset for SoCs checked)
- Define two options for reg: 1 item or 4 items.
- No reg-names.
- Add "clocks" and "clock-names" to list of properties.
- Clock is now "sec", not "secclk".
- Add "vcc-supply" to list of properties.
- Fixed up example.
- Don't provide "reset" value for things; just save/restore.
- Use the major/minor version read from 0x6000.
- Reading should still read "corrected", not "raw".
- Added a sysfs knob to allow you to read "raw" instead of "corrected"
- Simplified the SoC data structure.
- No need for quite so many levels of abstraction for clocks/regulator.
- Don't set regulator voltage.  Rely on device tree to make sure it's right.
- Properly undo things in the case of failure.
- Don't just keep enabling the regulator over and over again.
- Enable / disable the clock each time
- Polling every 100 us but timing out in 10 us didn't make sense; swap.
- No reason for 100 us to be SoC specific.
- No need for reg-names.
- We shouldn't be creating two separate nvmem devices.
- Name is now 'efuse' to match what schema checker wants.
- Reorganized ranges to match driver/bindings changes.
- Added 4th range as per driver/binding changes.
- No more reg-names as per driver/binding changes.
- Clock name is now just "sec" as per driver/binding changes.

Ravi Kumar Bokka (4):
  dt-bindings: nvmem: qfprom: Convert to yaml
  dt-bindings: nvmem: Add properties needed for blowing fuses
  nvmem: qfprom: Add fuse blowing support
  arm64: dts: qcom: sc7180: Add properties to qfprom for fuse blowing

 .../bindings/nvmem/qcom,qfprom.yaml           |  96 ++++++
 .../devicetree/bindings/nvmem/qfprom.txt      |  35 --
 arch/arm64/boot/dts/qcom/sc7180-idp.dts       |   4 +
 arch/arm64/boot/dts/qcom/sc7180.dtsi          |  10 +-
 drivers/nvmem/qfprom.c                        | 314 +++++++++++++++++-
 5 files changed, 411 insertions(+), 48 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
 delete mode 100644 Documentation/devicetree/bindings/nvmem/qfprom.txt

-- 
2.27.0.111.gc72c7da667-goog

[PATCH v4 1/4] dt-bindings: nvmem: qfprom: Convert to yaml

[Douglas Anderson]

From: Ravi Kumar Bokka <rbokka@codeaurora.org>

This switches the bindings over from txt to yaml.

Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v4:
- Maintainer now listed as Srinivas.
- Example under "soc" to get #address-cells and #size-cells.

Changes in v3:
- Split conversion to yaml into separate patch new in v3.
- Use 'const' for compatible instead of a 1-entry enum.
- Changed filename to match compatible string.
- Add #address-cells and #size-cells to list of properties.
- Fixed up example.

 .../bindings/nvmem/qcom,qfprom.yaml           | 50 +++++++++++++++++++
 .../devicetree/bindings/nvmem/qfprom.txt      | 35 -------------
 2 files changed, 50 insertions(+), 35 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
 delete mode 100644 Documentation/devicetree/bindings/nvmem/qfprom.txt

diff --git a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
new file mode 100644
index 000000000000..39f97c1c83a4
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/qcom,qfprom.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Technologies Inc, QFPROM Efuse bindings
+
+maintainers:
+  - Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+
+allOf:
+  - $ref: "nvmem.yaml#"
+
+properties:
+  compatible:
+    const: qcom,qfprom
+
+  reg:
+    items:
+      - description: The corrected region.
+
+  # Needed if any child nodes are present.
+  "#address-cells":
+    const: 1
+  "#size-cells":
+    const: 1
+
+required:
+   - compatible
+   - reg
+
+examples:
+  - |
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      efuse@784000 {
+        compatible = "qcom,qfprom";
+        reg = <0 0x00784000 0 0x8ff>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        hstx-trim-primary@1eb {
+          reg = <0x1eb 0x1>;
+          bits = <1 4>;
+        };
+      };
+    };
diff --git a/Documentation/devicetree/bindings/nvmem/qfprom.txt b/Documentation/devicetree/bindings/nvmem/qfprom.txt
deleted file mode 100644
index 26fe878d5c86..000000000000
--- a/Documentation/devicetree/bindings/nvmem/qfprom.txt
+++ /dev/null
@@ -1,35 +0,0 @@
-= Qualcomm QFPROM device tree bindings =
-
-This binding is intended to represent QFPROM which is found in most QCOM SOCs.
-
-Required properties:
-- compatible: should be "qcom,qfprom"
-- reg: Should contain registers location and length
-
-= Data cells =
-Are child nodes of qfprom, bindings of which as described in
-bindings/nvmem/nvmem.txt
-
-Example:
-
-	qfprom: qfprom@700000 {
-		compatible 	= "qcom,qfprom";
-		reg		= <0x00700000 0x8000>;
-		...
-		/* Data cells */
-		tsens_calibration: calib@404 {
-			reg = <0x4404 0x10>;
-		};
-	};
-
-
-= Data consumers =
-Are device nodes which consume nvmem data cells.
-
-For example:
-
-	tsens {
-		...
-		nvmem-cells = <&tsens_calibration>;
-		nvmem-cell-names = "calibration";
-	};
-- 
2.27.0.111.gc72c7da667-goog

Re: [PATCH v4 1/4] dt-bindings: nvmem: qfprom: Convert to yaml

[Rob Herring]

On Mon, 22 Jun 2020 07:49:26 -0700, Douglas Anderson wrote:
> From: Ravi Kumar Bokka <rbokka@codeaurora.org>
> 
> This switches the bindings over from txt to yaml.
> 
> Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
> Changes in v4:
> - Maintainer now listed as Srinivas.
> - Example under "soc" to get #address-cells and #size-cells.
> 
> Changes in v3:
> - Split conversion to yaml into separate patch new in v3.
> - Use 'const' for compatible instead of a 1-entry enum.
> - Changed filename to match compatible string.
> - Add #address-cells and #size-cells to list of properties.
> - Fixed up example.
> 
>  .../bindings/nvmem/qcom,qfprom.yaml           | 50 +++++++++++++++++++
>  .../devicetree/bindings/nvmem/qfprom.txt      | 35 -------------
>  2 files changed, 50 insertions(+), 35 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
>  delete mode 100644 Documentation/devicetree/bindings/nvmem/qfprom.txt
> 

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

[PATCH v4 2/4] dt-bindings: nvmem: Add properties needed for blowing fuses

[Douglas Anderson]

From: Ravi Kumar Bokka <rbokka@codeaurora.org>

On some systems it's possible to actually blow the fuses in the qfprom
from the kernel.  Add properties to support that.

NOTE: Whether this is possible depends on the BIOS settings and
whether the kernel has permissions here, so not all boards will be
able to blow fuses in the kernel.

Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v4:
- Clock name is "core", not "sec".
- Example under "soc" to get #address-cells and #size-cells.

Changes in v3:
- Add an extra reg range (at 0x6000 offset for SoCs checked)
- Define two options for reg: 1 item or 4 items.
- No reg-names.
- Add "clocks" and "clock-names" to list of properties.
- Clock is now "sec", not "secclk".
- Add "vcc-supply" to list of properties.
- Fixed up example.

 .../bindings/nvmem/qcom,qfprom.yaml           | 50 ++++++++++++++++++-
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
index 39f97c1c83a4..d10a0cf91ba7 100644
--- a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
+++ b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
@@ -17,8 +17,27 @@ properties:
     const: qcom,qfprom
 
   reg:
-    items:
-      - description: The corrected region.
+    # If the QFPROM is read-only OS image then only the corrected region
+    # needs to be provided.  If the QFPROM is writable then all 4 regions
+    # must be provided.
+    oneOf:
+      - items:
+          - description: The corrected region.
+      - items:
+          - description: The corrected region.
+          - description: The raw region.
+          - description: The config region.
+          - description: The security control region.
+
+  # Clock must be provided if QFPROM is writable from the OS image.
+  clocks:
+    maxItems: 1
+  clock-names:
+    const: core
+
+  # Supply reference must be provided if QFPROM is writable from the OS image.
+  vcc-supply:
+    description: Our power supply.
 
   # Needed if any child nodes are present.
   "#address-cells":
@@ -31,6 +50,33 @@ required:
    - reg
 
 examples:
+  - |
+    #include <dt-bindings/clock/qcom,gcc-sc7180.h>
+
+    soc {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      efuse@784000 {
+        compatible = "qcom,qfprom";
+        reg = <0 0x00784000 0 0x8ff>,
+              <0 0x00780000 0 0x7a0>,
+              <0 0x00782000 0 0x100>,
+              <0 0x00786000 0 0x1fff>;
+        clocks = <&gcc GCC_SEC_CTRL_CLK_SRC>;
+        clock-names = "core";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        vcc-supply = <&vreg_l11a_1p8>;
+
+        hstx-trim-primary@25b {
+          reg = <0x25b 0x1>;
+          bits = <1 3>;
+        };
+      };
+    };
+
   - |
     soc {
       #address-cells = <2>;
-- 
2.27.0.111.gc72c7da667-goog

Re: [PATCH v4 2/4] dt-bindings: nvmem: Add properties needed for blowing fuses

[Rob Herring]

On Mon, 22 Jun 2020 07:49:27 -0700, Douglas Anderson wrote:
> From: Ravi Kumar Bokka <rbokka@codeaurora.org>
> 
> On some systems it's possible to actually blow the fuses in the qfprom
> from the kernel.  Add properties to support that.
> 
> NOTE: Whether this is possible depends on the BIOS settings and
> whether the kernel has permissions here, so not all boards will be
> able to blow fuses in the kernel.
> 
> Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
> Changes in v4:
> - Clock name is "core", not "sec".
> - Example under "soc" to get #address-cells and #size-cells.
> 
> Changes in v3:
> - Add an extra reg range (at 0x6000 offset for SoCs checked)
> - Define two options for reg: 1 item or 4 items.
> - No reg-names.
> - Add "clocks" and "clock-names" to list of properties.
> - Clock is now "sec", not "secclk".
> - Add "vcc-supply" to list of properties.
> - Fixed up example.
> 
>  .../bindings/nvmem/qcom,qfprom.yaml           | 50 ++++++++++++++++++-
>  1 file changed, 48 insertions(+), 2 deletions(-)
> 

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

[PATCH v4 4/4] arm64: dts: qcom: sc7180: Add properties to qfprom for fuse blowing

[Douglas Anderson]

From: Ravi Kumar Bokka <rbokka@codeaurora.org>

This patch adds properties to the qfprom node to enable fuse blowing.

Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v4:
- Clock name is "core", not "sec".

Changes in v3:
- Name is now 'efuse' to match what schema checker wants.
- Reorganized ranges to match driver/bindings changes.
- Added 4th range as per driver/binding changes.
- No more reg-names as per driver/binding changes.
- Clock name is now just "sec" as per driver/binding changes.

 arch/arm64/boot/dts/qcom/sc7180-idp.dts |  4 ++++
 arch/arm64/boot/dts/qcom/sc7180.dtsi    | 10 ++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180-idp.dts b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
index 39dbfc89689e..4b3c6ebdc8d8 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-idp.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
@@ -287,6 +287,10 @@ vreg_bob: bob {
 	};
 };
 
+&qfprom {
+	vcc-supply = <&vreg_l11a_1p8>;
+};
+
 &qspi {
 	status = "okay";
 	pinctrl-names = "default";
diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
index 3a8076c8bdbf..bfbdace2d29c 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -498,9 +498,15 @@ gcc: clock-controller@100000 {
 			#power-domain-cells = <1>;
 		};
 
-		qfprom@784000 {
+		qfprom: efuse@784000 {
 			compatible = "qcom,qfprom";
-			reg = <0 0x00784000 0 0x8ff>;
+			reg = <0 0x00784000 0 0x8ff>,
+			      <0 0x00780000 0 0x7a0>,
+			      <0 0x00782000 0 0x100>,
+			      <0 0x00786000 0 0x1fff>;
+
+			clocks = <&gcc GCC_SEC_CTRL_CLK_SRC>;
+			clock-names = "core";
 			#address-cells = <1>;
 			#size-cells = <1>;
 
-- 
2.27.0.111.gc72c7da667-goog