From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932494AbdLTI1a (ORCPT ); Wed, 20 Dec 2017 03:27:30 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:35935 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754564AbdLTI0k (ORCPT ); Wed, 20 Dec 2017 03:26:40 -0500 X-Google-Smtp-Source: ACJfBov221VdtlvGmpF3nPQmIb7qfpz90YAoM9fnrozkUsq34UkeuHr/a3q3/ptFbfS97L8QjWAMPA== From: Bartosz Golaszewski To: Andy Shevchenko , Rob Herring , Mark Rutland , Linus Walleij , Peter Rosin Cc: linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH v2 1/2] dt-bindings: at24: new optional property - wp-gpios Date: Wed, 20 Dec 2017 09:26:32 +0100 Message-Id: <20171220082633.32237-2-brgl@bgdev.pl> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171220082633.32237-1-brgl@bgdev.pl> References: <20171220082633.32237-1-brgl@bgdev.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org AT24 EEPROMs have a write-protect pin, which - when pulled high - inhibits writes to the upper quadrant of memory (although it has been observed that on some chips it disables writing to the entire memory range). On some boards, this pin is connected to a GPIO and pulled high by default, which forces the user to manually change its state before writing. On linux this means that we either need to hog the line all the time, or set the GPIO value before writing from outside of the at24 driver. Add a new optional property to the device tree binding document, which allows to specify the GPIO line to which the write-protect pin is connected. Signed-off-by: Bartosz Golaszewski --- Documentation/devicetree/bindings/eeprom/at24.txt | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/devicetree/bindings/eeprom/at24.txt b/Documentation/devicetree/bindings/eeprom/at24.txt index a0415b8471bb..cbc80e194ac6 100644 --- a/Documentation/devicetree/bindings/eeprom/at24.txt +++ b/Documentation/devicetree/bindings/eeprom/at24.txt @@ -43,10 +43,13 @@ Optional properties: eeprom does not automatically roll over reads to the next slave address. Please consult the manual of your device. + - wp-gpios: GPIO to which the write-protect pin of the chip is connected. + Example: eeprom@52 { compatible = "atmel,24c32"; reg = <0x52>; pagesize = <32>; + wp-gpios = <&gpio1 3 0>; }; -- 2.15.1