Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755155AbaDPRTs (ORCPT ); Wed, 16 Apr 2014 13:19:48 -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 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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: -- 1.8.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/