From patchwork Tue Jan 2 13:19:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 854540 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3z9vqC6JxVz9t3n for ; Wed, 3 Jan 2018 00:21:59 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751678AbeABNV5 (ORCPT ); Tue, 2 Jan 2018 08:21:57 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:59297 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751615AbeABNV4 (ORCPT ); Tue, 2 Jan 2018 08:21:56 -0500 Received: from tarshish.tkos.co.il (unknown [10.0.8.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPSA id 1A9AA4409E7; Tue, 2 Jan 2018 15:21:54 +0200 (IST) From: Baruch Siach To: Dave Stevenson , Eric Anholt , Stefan Wahren , Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, devicetree@vger.kernel.org, Baruch Siach Subject: [PATCH 2/4] dt-bindings: gpio: add raspberry pi GPIO expander binding Date: Tue, 2 Jan 2018 15:19:19 +0200 Message-Id: <4ca1795c6e09eb89f481cdec55180b4f1165bbfd.1514898134.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.15.1 In-Reply-To: References: Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware over I2C. The firmware mailbox interface allows the ARM core to control the GPIO lines. Signed-off-by: Baruch Siach --- .../bindings/gpio/brcm,bcm2835-expgpio.txt | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt diff --git a/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt new file mode 100644 index 000000000000..55257f31a9be --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/brcm,bcm2835-expgpio.txt @@ -0,0 +1,24 @@ +Raspberry Pi GPIO expander + +The Raspberry Pi 3 GPIO expander is controlled by the VC4 firmware. The +firmware exposes a mailbox interface that allows the ARM core to control the +GPIO lines on the expander. + +Required properties: + +- compatible : Should be "brcm,bcm2835-expgpio" +- gpio-controller : Marks the device node as a gpio controller +- #gpio-cells : Should be two. The first cell is the pin number, and + the second cell is used to specify the gpio polarity: + 0 = active high + 1 = active low +- firmware : Reference to the RPi firmware device node + +Example: + +expgpio: expgpio { + compatible = "brcm,bcm2835-expgpio"; + gpio-controller; + #gpio-cells = <2>; + firmware = <&firmware>; +};