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From: Wei Wang <wvw@google.com>
To: unlisted-recipients:; (no To-header on input)
Cc: wei.vince.wang@gmail.com, Wei Wang <wvw@google.com>,
	Zhang Rui <rui.zhang@intel.com>,
	Eduardo Valentin <edubezval@gmail.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Kucheria <amit.kucheria@verdurent.com>,
	linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 2/2] thermal: create softlink by name for thermal_zone and cooling_device
Date: Wed,  4 Dec 2019 13:56:18 -0800
Message-ID: <20191204215618.125826-3-wvw@google.com> (raw)
In-Reply-To: <20191204215618.125826-1-wvw@google.com>

The paths thermal_zone%d and cooling_device%d are not intuitive and the
numbers are subject to change due to device tree change. This usually
leads to tree traversal in userspace code.
The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
cooling_device respectively.

Signed-off-by: Wei Wang <wvw@google.com>
---
 drivers/thermal/thermal_core.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 64fbb59c2f44..4f55e3f16265 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -22,6 +22,7 @@
 #include <net/netlink.h>
 #include <net/genetlink.h>
 #include <linux/suspend.h>
+#include <linux/kobject.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/thermal.h>
@@ -46,6 +47,8 @@ static DEFINE_MUTEX(poweroff_lock);
 
 static atomic_t in_suspend;
 static bool power_off_triggered;
+static struct kobject *cdev_link_kobj;
+static struct kobject *tz_link_kobj;
 
 static struct thermal_governor *def_governor;
 
@@ -997,9 +1000,15 @@ __thermal_cooling_device_register(struct device_node *np,
 		return ERR_PTR(result);
 	}
 
-	/* Add 'this' new cdev to the global cdev list */
+	/* Add 'this' new cdev to the global cdev list and create link*/
 	mutex_lock(&thermal_list_lock);
 	list_add(&cdev->node, &thermal_cdev_list);
+	if (!cdev_link_kobj)
+		cdev_link_kobj = kobject_create_and_add("cdev-by-name",
+						cdev->device.kobj.parent);
+	if (!cdev_link_kobj || sysfs_create_link(cdev_link_kobj,
+						&cdev->device.kobj, cdev->type))
+		dev_err(&cdev->device, "Failed to create cdev-by-name link\n");
 	mutex_unlock(&thermal_list_lock);
 
 	/* Update binding information for 'this' new cdev */
@@ -1165,6 +1174,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
 			}
 		}
 	}
+	if (cdev_link_kobj)
+		sysfs_remove_link(cdev_link_kobj, cdev->type);
 
 	mutex_unlock(&thermal_list_lock);
 
@@ -1348,6 +1359,12 @@ thermal_zone_device_register(const char *type, int trips, int mask,
 
 	mutex_lock(&thermal_list_lock);
 	list_add_tail(&tz->node, &thermal_tz_list);
+	if (!tz_link_kobj)
+		tz_link_kobj = kobject_create_and_add("tz-by-name",
+						tz->device.kobj.parent);
+	if (!tz_link_kobj || sysfs_create_link(tz_link_kobj,
+						&tz->device.kobj, tz->type))
+		dev_err(&tz->device, "Failed to create tz-by-name link\n");
 	mutex_unlock(&thermal_list_lock);
 
 	/* Bind cooling devices for this zone */
@@ -1419,6 +1436,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 			}
 		}
 	}
+	if (tz_link_kobj)
+		sysfs_remove_link(tz_link_kobj, tz->type);
 
 	mutex_unlock(&thermal_list_lock);
 
-- 
2.24.0.393.g34dc348eaf-goog


  parent reply index

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-15  6:13 [PATCH] " Wei Wang
2019-10-16 16:50 ` Amit Kucheria
2019-10-16 17:15   ` Amit Kucheria
2019-10-16 21:34     ` Wei Wang
2019-11-11  5:26       ` Amit Kucheria
2019-11-11 17:52         ` Wei Wang
2019-12-04 12:45           ` Amit Kucheria
2019-12-04 21:56             ` [PATCH v2 0/2] thermal: introduce by-name softlink Wei Wang
2019-12-04 21:56               ` [PATCH v2 1/2] thermal: fix and clean up tz and cdev registration Wei Wang
2019-12-05  4:13                 ` Amit Kucheria
2019-12-05  6:14                   ` Wei Wang
2019-12-05  6:26                     ` Amit Kucheria
2019-12-05  7:06                       ` Amit Kucheria
2019-12-05  7:56                         ` Zhang Rui
2019-12-04 21:56               ` Wei Wang [this message]
2019-12-05  4:14                 ` [PATCH v2 2/2] thermal: create softlink by name for thermal_zone and cooling_device Amit Kucheria
2019-12-04 21:58             ` [PATCH] " Wei Wang

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