Re: [PATCH v3 2/4] dt-bindings: nvmem: Add properties needed for blowing fuses

From: Srinivas Kandagatla
Date: Wed Jun 17 2020 - 11:19:07 EST




On 17/06/2020 15:51, Douglas Anderson wrote:
From: Ravi Kumar Bokka <rbokka@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

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 | 45 ++++++++++++++++++-
1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
index 5efa5e7c4d81..b195212c6193 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: sec

Do we need clock-names for just one clock here?

+
+ # 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 +50,28 @@ required:
- reg
examples:
+ - |
+ #include <dt-bindings/clock/qcom,gcc-sc7180.h>
+
+ 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 = "sec";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ vcc-supply = <&vreg_l11a_1p8>;
+
+ hstx-trim-primary@25b {
+ reg = <0x25b 0x1>;
+ bits = <1 3>;
+ };
+ };
+
- |
efuse@784000 {
compatible = "qcom,qfprom";