Re: [PATCH v7 1/3] Documentation: dt: net: add ath9k wireless device binding

On Sun, Oct 9, 2016 at 3:28 AM, Rob Herring [off-list ref] wrote:

On Sun, Oct 02, 2016 at 11:47:41PM +0200, Martin Blumenstingl wrote:

quoted

Add documentation how devicetree can be used to configure ath9k based
devices.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 .../devicetree/bindings/net/wireless/qca,ath9k.txt | 30 ++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt

diff --git a/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt b/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
new file mode 100644
index 0000000..9b58ede
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt

@@ -0,0 +1,30 @@
+* Qualcomm Atheros ath9k wireless devices
+
+This node provides properties for configuring the ath9k wireless device. The
+node is expected to be specified as a child node of the PCI controller to
+which the wireless chip is connected.
+
+Required properties:
+- compatible: For PCI and PCIe devices this should be an identifier following
+             the format as defined in "PCI Bus Binding to Open Firmware"
+             Revision 2.1. One of the possible formats is "pciVVVV,DDDD"
+             where VVVV is the PCI vendor ID and DDDD is PCI device ID.

Are there some known values you can document here? Like the one in the
example.

what do you have in mind there?

there are lots of supported device IDs just with vendor 0x168c (Atheros):
echo $(grep 'PCI_VDEVICE(ATHEROS'
drivers/net/wireless/ath/ath9k/pci.c; grep '{
PCI_DEVICE_SUB(PCI_VENDOR_ID_ATHEROS'
drivers/net/wireless/ath/ath9k/pci.c -A1) | grep -Eo "0x[
0-9A-Z]{4}" | sort -u
Also some device IDs seem to be used by different chips, for example
0x0029 is used for both, AR9220 and AR9223 - see [0]

I could extend the documentation with something like:
vendor ID is usually 168c (Atheros) and device ID is one of the
following, depending on the actual chipset:
- 002d: AR9227 (PCI variant of AR9287)
- 002e: AR9287 (PCI-e)
- ...

quoted

+- reg: Address and length of the register set for the device.
+
+Optional properties:
+- qca,no-eeprom: Indicates that there is no physical EEPROM connected to the
+                     ath9k wireless chip (in this case the calibration /
+                     EEPROM data will be loaded from userspace using the
+                     kernel firmware loader).
+- mac-address: See ethernet.txt in the parent directory
+- local-mac-address: See ethernet.txt in the parent directory
+
+
+In this example, the node is defined as child node of the PCI controller:
+&pci0 {
+     ath9k@168c,002d {

wifi@...

will fix that, thanks for the hint


[0] https://wireless.wiki.kernel.org/en/users/drivers/ath9k/devices