From patchwork Wed Apr 16 17:17:21 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergey Yanovich X-Patchwork-Id: 339681 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 0CE9F140077 for ; Thu, 17 Apr 2014 03:22:53 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754607AbaDPRTr (ORCPT ); Wed, 16 Apr 2014 13:19:47 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:50659 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755067AbaDPRTj (ORCPT ); Wed, 16 Apr 2014 13:19:39 -0400 Received: by mail-lb0-f174.google.com with SMTP id u14so8392747lbd.33 for ; Wed, 16 Apr 2014 10:19:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Ynlmndnhk7LyZ8DMA3ycJ7m9e5XweOm5KPhstbzcuJY=; b=qB/Si+vETSE8QzRBnIi9hqZglW0TZnutsYAQteWPxJqxOHK1nz7hxLSw05Ag2EuWb7 EKL86N0yrhBrguKsLb8wYajOcwvSxSFNfuzrqvU2wkT7Sd6aNCh57wUNzUF4PePLjhGe RXhREK0/9imf0PxpOPDbImRskFY7cQOv2nE9LOGWe+Zws/sDivfOG3q/1La7vgGXdUHr Pjp6cYg2DZTgwSwEBvqLNQ3BZdqVt7bZ00lFjGN7JPGXV2xONJqQSDyovKAE3aeewNdE 0R1u8rbqb/gR5S90d+5lN11iBBbvVhXLTs0Rm2pdvDZUAAQeBozrslHT/TqVUmfr+TXe m9/A== X-Received: by 10.152.87.102 with SMTP id w6mr2334259laz.46.1397668777285; Wed, 16 Apr 2014 10:19:37 -0700 (PDT) Received: from host5.omatika.ru (0893675324.static.corbina.ru. [95.31.1.192]) by mx.google.com with ESMTPSA id q4sm21186297lbh.20.2014.04.16.10.19.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 16 Apr 2014 10:19:36 -0700 (PDT) From: Sergei Ianovich To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Sergei Ianovich , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Randy Dunlap , Arnd Bergmann , Greg Kroah-Hartman , devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND...), linux-doc@vger.kernel.org (open list:DOCUMENTATION) Subject: [PATCH v4 16/21] misc: support for writing to LP-8x4x EEPROM Date: Wed, 16 Apr 2014 21:17:21 +0400 Message-Id: <1397668667-27328-10-git-send-email-ynvich@gmail.com> X-Mailer: git-send-email 1.9.2 In-Reply-To: <1397668667-27328-1-git-send-email-ynvich@gmail.com> References: <1397668411-27162-7-git-send-email-ynvich@gmail.com> <1397668667-27328-1-git-send-email-ynvich@gmail.com> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org at24c128 write protection is implemented by a separate GPIO line. EEPROM driver doesn't provide this option, so we implement it in the board-specific device. Signed-off-by: Sergei Ianovich --- v3..v4 * move DTS binding to a different patch (8/21) v2..v3 * new patch .../devicetree/bindings/misc/lp8x4x-bus.txt | 3 ++ Documentation/misc-devices/lp8x4x_bus.txt | 3 ++ drivers/misc/lp8x4x_bus.c | 50 ++++++++++++++++++++++ 3 files changed, 56 insertions(+) diff --git a/Documentation/devicetree/bindings/misc/lp8x4x-bus.txt b/Documentation/devicetree/bindings/misc/lp8x4x-bus.txt index 1b1776a..b0fb145 100644 --- a/Documentation/devicetree/bindings/misc/lp8x4x-bus.txt +++ b/Documentation/devicetree/bindings/misc/lp8x4x-bus.txt @@ -10,6 +10,8 @@ Required properties: * the 8bit DIP switch * the slot count register +- eeprom-gpios : should point to active-low write enable GPIO + Example: backplane { @@ -17,4 +19,5 @@ Example: reg = <0x0 0x2 0x9002 0x2 0x9046 0x2>; + eeprom-gpios = <&gpio 4 0>; }; diff --git a/Documentation/misc-devices/lp8x4x_bus.txt b/Documentation/misc-devices/lp8x4x_bus.txt index 829781b..78ea0a89 100644 --- a/Documentation/misc-devices/lp8x4x_bus.txt +++ b/Documentation/misc-devices/lp8x4x_bus.txt @@ -29,6 +29,9 @@ SYSFS dip RO - shows status of LP-8x4x 8bit DIP switch +eeprom_write_enable + RW - controls write access to board's EEPROM (1 - enable) + rotary RO - shows position of LP-8x4x rotary switch (0-9) diff --git a/drivers/misc/lp8x4x_bus.c b/drivers/misc/lp8x4x_bus.c index dfbc8c4..567fe078 100644 --- a/drivers/misc/lp8x4x_bus.c +++ b/drivers/misc/lp8x4x_bus.c @@ -9,6 +9,7 @@ * published by the Free Software Foundation or any later version. */ #include +#include #include #include #include @@ -27,6 +28,7 @@ struct lp8x4x_master { void *count_addr; void *rotary_addr; void *dip_addr; + struct gpio_desc *eeprom_nWE; struct device dev; }; @@ -68,6 +70,40 @@ static ssize_t rotary_show(struct device *dev, static DEVICE_ATTR_RO(rotary); +static ssize_t eeprom_write_enable_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct lp8x4x_master *m = container_of(dev, struct lp8x4x_master, dev); + + return sprintf(buf, "%u\n", !gpiod_get_value(m->eeprom_nWE)); +} + +static ssize_t eeprom_write_enable_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct lp8x4x_master *m = container_of(dev, struct lp8x4x_master, dev); + unsigned int val = 0; + int err; + + if (!buf) + return count; + + if (0 == count) + return count; + + err = kstrtouint(buf, 10, &val); + if (err != 0) { + dev_err(dev, "Bad input %s\n", buf); + return count; + } + + gpiod_set_value(m->eeprom_nWE, !val); + + return count; +} + +static DEVICE_ATTR_RW(eeprom_write_enable); + static ssize_t dip_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -81,6 +117,7 @@ static DEVICE_ATTR_RO(dip); static struct attribute *master_dev_attrs[] = { &dev_attr_slot_count.attr, &dev_attr_rotary.attr, + &dev_attr_eeprom_write_enable.attr, &dev_attr_dip.attr, NULL, }; @@ -156,6 +193,19 @@ static int __init lp8x4x_bus_probe(struct platform_device *pdev) goto err_free; } + m->eeprom_nWE = devm_gpiod_get(&pdev->dev, "eeprom"); + if (IS_ERR(m->eeprom_nWE)) { + err = PTR_ERR(m->eeprom_nWE); + dev_err(&pdev->dev, "Failed to get eeprom GPIO\n"); + goto err_free; + } + + err = gpiod_direction_output(m->eeprom_nWE, 1); + if (err < 0) { + dev_err(&pdev->dev, "Failed to set eeprom GPIO output\n"); + goto err_free; + } + m->slot_count = ioread8(m->count_addr); switch (m->slot_count) { case 1: