From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760328AbZKZMG0 (ORCPT ); Thu, 26 Nov 2009 07:06:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760306AbZKZMGZ (ORCPT ); Thu, 26 Nov 2009 07:06:25 -0500 Received: from mail-bw0-f227.google.com ([209.85.218.227]:37110 "EHLO mail-bw0-f227.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752437AbZKZMGY (ORCPT ); Thu, 26 Nov 2009 07:06:24 -0500 From: Amit Kucheria To: List Linux Kernel Cc: rui.zhang@intel.com, jic23@cam.ac.uk, khali@linux-fr.org, alan@linux.intel.com, linux-acpi@vger.kernel.org, gregkh@suse.de Subject: [PATCH 2/2] als: add unique device-ids to the als device class Date: Thu, 26 Nov 2009 14:06:26 +0200 Message-Id: <1259237186-5459-1-git-send-email-amit.kucheria@verdurent.com> X-Mailer: git-send-email 1.6.3.3 In-Reply-To: <1259237081-4403-1-git-send-email-amit.kucheria@verdurent.com> References: <1259237081-4403-1-git-send-email-amit.kucheria@verdurent.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Other devices classes such as hwmon and input class handle assignment of unique device-ids inside the core functions instead of pushing it out to individual drivers. This reduces code duplication and resulting bugs. Signed-off-by: Amit Kucheria Cc: Zhang Rui Cc: Jonathan Cameron --- drivers/als/als_sys.c | 48 +++++++++++++++++++++++++++++++++++++++++++++--- 1 files changed, 45 insertions(+), 3 deletions(-) diff --git a/drivers/als/als_sys.c b/drivers/als/als_sys.c index e1d6395..aa15ad8 100644 --- a/drivers/als/als_sys.c +++ b/drivers/als/als_sys.c @@ -26,22 +26,55 @@ #include #include #include +#include MODULE_AUTHOR("Zhang Rui "); MODULE_DESCRIPTION("Ambient Light Sensor sysfs/class support"); MODULE_LICENSE("GPL"); +#define ALS_ID_PREFIX "als" +#define ALS_ID_FORMAT ALS_ID_PREFIX "%d" + static struct class *als_class; +static DEFINE_IDR(als_idr); +static DEFINE_SPINLOCK(idr_lock); + /** * als_device_register - register a new Ambient Light Sensor class device * @parent: the device to register. * * Returns the pointer to the new device */ -struct device *als_device_register(struct device *dev, char *name) +struct device *als_device_register(struct device *dev) { - return device_create(als_class, dev, MKDEV(0, 0), NULL, name); + int id, err; + struct device *alsdev; + +again: + if (unlikely(idr_pre_get(&als_idr, GFP_KERNEL) == 0)) + return ERR_PTR(-ENOMEM); + + spin_lock(&idr_lock); + err = idr_get_new(&als_idr, NULL, &id); + spin_unlock(&idr_lock); + + if (unlikely(err == -EAGAIN)) + goto again; + else if (unlikely(err)) + return ERR_PTR(err); + + id = id & MAX_ID_MASK; + alsdev = device_create(als_class, dev, MKDEV(0, 0), NULL, + ALS_ID_FORMAT, id); + + if (IS_ERR(alsdev)) { + spin_lock(&idr_lock); + idr_remove(&als_idr, id); + spin_unlock(&idr_lock); + } + + return alsdev; } EXPORT_SYMBOL(als_device_register); @@ -51,7 +84,16 @@ EXPORT_SYMBOL(als_device_register); */ void als_device_unregister(struct device *dev) { - device_unregister(dev); + int id; + + if (likely(sscanf(dev_name(dev), ALS_ID_FORMAT, &id) == 1)) { + device_unregister(dev); + spin_lock(&idr_lock); + idr_remove(&als_idr, id); + spin_unlock(&idr_lock); + } else + dev_dbg(dev->parent, + "als_device_unregister() failed: bad class ID!\n"); } EXPORT_SYMBOL(als_device_unregister); -- 1.6.3.3