Thread (23 messages) 23 messages, 6 authors, 2021-09-15

RE: [PATCH v1 5/6] TODO: gpio: mlxbf2: Introduce IRQ support

From: Asmaa Mnebhi <asmaa@nvidia.com>
Date: 2021-08-19 12:28:43
Also in: linux-acpi, lkml, netdev

Thank you Andrew and Andy! I will prepare 2 patches (one for gpio-mlxbf2.c and one for mlxbf-gige) and send it your way.

-----Original Message-----
From: Andrew Lunn <andrew@lunn.ch> 
Sent: Wednesday, August 18, 2021 6:40 PM
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Asmaa Mnebhi <asmaa@nvidia.com>; David Thompson <davthompson@nvidia.com>; linux-kernel@vger.kernel.org; linux-gpio@vger.kernel.org; netdev@vger.kernel.org; linux-acpi@vger.kernel.org; Linus Walleij <redacted>; Bartosz Golaszewski <redacted>; David S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Rafael J. Wysocki <redacted>; Liming Sun <redacted>
Subject: Re: [PATCH v1 5/6] TODO: gpio: mlxbf2: Introduce IRQ support
Importance: High

Hi Asmaa
quoted
And I will need to add GpioInt to the GPI0 ACPI table as follows:
But you told me that it's already on the market, how are you suppose 
to change existing tables?
BIOSes have as many bugs a the kernel. So your product should be designed so you can upgrade the kernel and upgrade the BIOS.

phylib itself does not care if there is an interrupt or not. It will fall back to polling. So if your driver finds itself running with old tables, it does not matter. Just print a warning to the kernel logs suggesting the user upgrades their BIOS firmware.
quoted
// GPIO Controller
      Device(GPI0) {
       Name(_HID, "MLNXBF22")
        Name(_UID, Zero)
        Name(_CCA, 1)
        Name(_CRS, ResourceTemplate() {
          // for gpio[0] yu block
         Memory32Fixed(ReadWrite, 0x0280c000, 0x00000100)
         GpioInt (Level, ActiveLow, Exclusive, PullDefault, , " \\_SB.GPI0") {9}
        })
        Name(_DSD, Package() {
          ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
          Package() {
            Package () { "phy-gpios", Package() {^GPI0, 0, 0, 0 }},
            Package () { "rst-pin", 32 }, // GPIO pin triggering soft reset on BlueSphere and PRIS
          }
        })
      }
No, it's completely wrong. The resources are provided by GPIO 
controller and consumed by devices.
In the device tree world, you list the interrupt in the PHY node.
Documentation/devicetree/bindings/net/ethernet-phy.yaml gives an
example:

    ethernet {
        #address-cells = <1>;
        #size-cells = <0>;

        ethernet-phy@0 {
            compatible = "ethernet-phy-id0141.0e90", "ethernet-phy-ieee802.3-c45";
            interrupt-parent = <&PIC>;
            interrupts = <35 1>;
            reg = <0>;

            resets = <&rst 8>;
            reset-names = "phy";
            reset-gpios = <&gpio1 4 1>;
            reset-assert-us = <1000>;
            reset-deassert-us = <2000>;
        };
    };

You need to do something similar in the ACPI world. There was a very long discussion in this area recently, and some patches merged. You probably need to build on that. See:

firmware-guide/acpi/dsd/phy.rst

	Andrew
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help