Re: [PATCH RFC 05/14] dt-bindings/interrupt-controller: pdc: add SPI config register

From: Lina Iyer
Date: Tue Sep 03 2019 - 13:07:27 EST

On Mon, Sep 02 2019 at 07:58 -0600, Marc Zyngier wrote:
On 02/09/2019 14:38, Rob Herring wrote:
On Thu, Aug 29, 2019 at 12:11:54PM -0600, Lina Iyer wrote:
In addition to configuring the PDC, additional registers that interface
the GIC have to be configured to match the GPIO type. The registers on
some QCOM SoCs are access restricted, while on other SoCs are not. They
SoCs with access restriction to these SPI registers need to be written

Took me a minute to figure out this is GIC SPI interrupts, not SPI bus.

from the firmware using the SCM interface. Add a flag to indicate if the
register is to be written using SCM interface.

Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
.../bindings/interrupt-controller/qcom,pdc.txt | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
index 8e0797cb1487..852fcba98ea6 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
@@ -50,15 +50,22 @@ Properties:
The second element is the GIC hwirq number for the PDC port.
The third element is the number of interrupts in sequence.

+- qcom,scm-spi-cfg:
+ Usage: optional
+ Value type: <bool>
+ Definition: Specifies if the SPI configuration registers have to be
+ written from the firmware.

pdc: interrupt-controller@b220000 {
compatible = "qcom,sdm845-pdc";
- reg = <0xb220000 0x30000>;
+ reg = <0xb220000 0x30000>, <0x179900f0 0x60>;

There needs to be a description for reg updated. These aren't GIC
registers are they? Because those go in the GIC node.

They are not GIC registers. I will update this documentation.

This is completely insane. Why are the GIC registers configured as
secure the first place, if they are expected to be in control of the
These are not GIC registers but located on the PDC interface to the GIC.
They may or may not be secure access controlled, depending on the SoC.