[v3,3/3] thermal: create softlink by name for thermal_zone and cooling_device
diff mbox series

Message ID 20191205071953.121511-4-wvw@google.com
State New
Delegated to: Zhang Rui
Headers show
Series
  • thermal: introduce by-name softlink
Related show

Commit Message

Wei Wang Dec. 5, 2019, 7:19 a.m. UTC
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>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
---
 drivers/thermal/thermal_core.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

Comments

Matthias Kaehlcke Dec. 6, 2019, 7:15 p.m. UTC | #1
On Wed, Dec 04, 2019 at 11:19:53PM -0800, Wei Wang wrote:
> 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.

This is useful, especially for systems with plenty of thermal zones :)

> Signed-off-by: Wei Wang <wvw@google.com>
> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
> ---
>  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 9db7f72e70f8..7872bd527f3f 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;
>  
> @@ -999,9 +1002,15 @@ __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 */
> @@ -1167,6 +1176,8 @@ 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);
>  
> @@ -1354,6 +1365,12 @@ 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 */
> @@ -1425,6 +1442,8 @@ 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);
>  

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Amit Kucheria Dec. 9, 2019, 7:42 a.m. UTC | #2
On Thu, Dec 5, 2019 at 12:50 PM Wei Wang <wvw@google.com> wrote:
>
> 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>
> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>

Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
> ---
>  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 9db7f72e70f8..7872bd527f3f 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;
>
> @@ -999,9 +1002,15 @@ __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 */
> @@ -1167,6 +1176,8 @@ 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);
>
> @@ -1354,6 +1365,12 @@ 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 */
> @@ -1425,6 +1442,8 @@ 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
>

Patch
diff mbox series

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 9db7f72e70f8..7872bd527f3f 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;
 
@@ -999,9 +1002,15 @@  __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 */
@@ -1167,6 +1176,8 @@  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);
 
@@ -1354,6 +1365,12 @@  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 */
@@ -1425,6 +1442,8 @@  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);