Re: [PATCH V2 1/2] dt-bindings: usb: misc: Add binding for Microchip usb2244 Controller

From: Michal Simek
Date: Tue Nov 30 2021 - 05:23:48 EST




On 11/30/21 03:11, Rob Herring wrote:
On Mon, Nov 22, 2021 at 11:58:33AM +0530, Piyush Mehta wrote:
Microchip's USB224x family of Hi-Speed USB 2.0 flash media card controllers
provides an ultra-fast interface between a USB host controller and flash
media cards.

Add dt-bindings documentation for Microchip's usb2244 Controller.
USB224x is a USB 2.0 compliant ultra fast USB 2.0 multi-format,
SD/MMC, and MS Flash Media Controllers.

Signed-off-by: Piyush Mehta <piyush.mehta@xxxxxxxxxx>
---
Changes for V2:
- Update reset polarity, make reset ACTIVE LOW in the dt-binding document.
- Added usbsd node under the usb controller (usb0) node.
- Remove Warning: decoded text below may be mangled, UTF-8 assumed.

Review comments:
Link: https://lore.kernel.org/lkml/CAL_JsqKu6vr3iCz1G7MtK6gyqAvn4s4mpuLOwPzJDEmyZeROig@xxxxxxxxxxxxxx/
---
.../devicetree/bindings/usb/microchip,usb2244.yaml | 47 ++++++++++++++++++++++
1 file changed, 47 insertions(+)
create mode 100644 Documentation/devicetree/bindings/usb/microchip,usb2244.yaml

diff --git a/Documentation/devicetree/bindings/usb/microchip,usb2244.yaml b/Documentation/devicetree/bindings/usb/microchip,usb2244.yaml
new file mode 100644
index 0000000..1854313
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/microchip,usb2244.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/usb/microchip,usb2244.yaml#";
+$schema: "http://devicetree.org/meta-schemas/core.yaml#";
+
+title: Bindings for the Microchip USB2244 Ultra Fast USB-SD Controller
+
+description:
+ Microchip USB224x is a USB 2.0 compliant, Hi-Speed bulk only mass
+ storage class peripheral controller intended for reading and writing
+ to popular flash media from the xDPicture Card, Memory Stick (MS),
+ Secure Digital (SD), and MultiMediaCard (MMC) families.
+
+ USB224x is a flash media card reader solution fully compliant with the
+ USB 2.0 specification.
+
+maintainers:
+ - Piyush Mehta <piyush.mehta@xxxxxxxxxx>
+
+properties:
+ compatible:
+ const: microchip,usb2244
+
+ reset-gpios:
+ maxItems: 1
+ description:
+ The phandle and specifier for the GPIO that controls the RESET line of
+ flash media controller.
+
+required:
+ - compatible
+ - reset-gpios
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ usb0 {
+ usbsd {
+ compatible = "microchip,usb2244";
+ reset-gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
+ };

This is not how the USB device binding works. See usb-device.yaml.


Is this fine?

device@1 {
compatible = "usb424,2240";
reg = <1>;
reset-gpios = <&gpio 2 GPIO_ACTIVE_LOW>;
};

If yes, this means that we should use usb driver instead of platform driver.

Thanks,
Michal