From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752881Ab3AVJqd (ORCPT ); Tue, 22 Jan 2013 04:46:33 -0500 Received: from mail-bk0-f44.google.com ([209.85.214.44]:51935 "EHLO mail-bk0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154Ab3AVJqa (ORCPT ); Tue, 22 Jan 2013 04:46:30 -0500 Date: Tue, 22 Jan 2013 09:46:24 +0000 From: Lee Jones To: broonie@opensource.wolfsonmicro.com Cc: linux-kernel@vger.kernel.org Subject: [RFC] regulator: Display in use regulators in sysfs Message-ID: <20130122094624.GJ6857@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Please excuse any poor formatting that may occur, as this is copy-paste into my mailer, but what do you think of this idea? To locate a consumer that currently holds a regulattor, a new sysfs entry is created. The consumer are published in /sys/class/regulator/regulator.<#>/use. --- drivers/regulator/core.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 046fb1b..40fd150 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -81,6 +81,7 @@ struct regulator { struct device_attribute dev_attr; struct regulator_dev *rdev; struct dentry *debugfs; + int use; }; static int _regulator_is_enabled(struct regulator_dev *rdev); @@ -602,6 +603,32 @@ static ssize_t regulator_suspend_standby_state_show(struct device *dev, static DEVICE_ATTR(suspend_standby_state, 0444, regulator_suspend_standby_state_show, NULL); +static ssize_t regulator_use_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct regulator_dev *rdev = dev_get_drvdata(dev); + struct regulator *reg; + size_t size = 0; + + if (rdev->use_count == 0) + return sprintf(buf, "no users\n"); + + list_for_each_entry(reg, &rdev->consumer_list, list) { + if (!reg->use) + continue; + + if (reg->dev != NULL) + size += sprintf((buf + size), "%s (%d) ", + dev_name(reg->dev), reg->use); + else + size += sprintf((buf + size), "unknown (%d) ", + reg->use); + } + size += sprintf((buf + size), "\n"); + + return size; +} +static DEVICE_ATTR(use, 0444, regulator_use_show, NULL); /* * These are the only attributes are present for all regulators. @@ -1540,6 +1567,8 @@ int regulator_enable(struct regulator *regulator) if (ret != 0 && rdev->supply) regulator_disable(rdev->supply); + else + regulator->use++; return ret; } @@ -1613,6 +1642,9 @@ int regulator_disable(struct regulator *regulator) if (ret == 0 && rdev->supply) regulator_disable(rdev->supply); + if (ret == 0) + regulator->use--; + return ret; } EXPORT_SYMBOL_GPL(regulator_disable); @@ -2699,6 +2731,10 @@ static int add_regulator_attributes(struct regulator_dev *rdev) struct regulator_ops *ops = rdev->desc->ops; int status = 0; + status = device_create_file(dev, &dev_attr_use); + if (status < 0) + dev_warn(dev, "Create sysfs file \"use\" failed"); + /* some attributes need specific methods to be displayed */ if ((ops->get_voltage && ops->get_voltage(rdev) >= 0) || (ops->get_voltage_sel && ops->get_voltage_sel(rdev) >= 0)) { -- Lee Jones Linaro ST-Ericsson Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog