From: wni@nvidia.com (Wei Ni)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH 5/9] Thermal: Support using dt node to get sensor
Date: Wed, 20 Feb 2013 18:36:00 +0800 [thread overview]
Message-ID: <5124A710.1050205@nvidia.com> (raw)
In-Reply-To: <512406F0.4080708@wwwdotorg.org>
On 02/20/2013 07:12 AM, Stephen Warren wrote:
> On 02/18/2013 04:30 AM, Wei Ni wrote:
>> Add functions to support using dt node with args to get sensor.
>
> You need to write a device tree binding document to explain this.
>
>> diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
>
>> +struct thermal_sensor *get_sensor_by_node(struct node_args *np_args)
>> +{
>> + struct thermal_sensor *pos;
>
> "pos" isn't a great variable name. Why not use "sensor", or just the
> "ts" variable you have right below?
Oh, yes, it can just use "ts" simply. I didn't consider it, thanks.
>
>> + struct thermal_sensor *ts = NULL;
>> + struct node_args *args;
>> +
>> + mutex_lock(&sensor_list_lock);
>> + for_each_thermal_sensor(pos) {
>> + args = &pos->np_args;
>> + if (args->np) {
>> + if ((args->np == np_args->np) &&
>> + (args->index == np_args->index)) {
>> + ts = pos;
>> + break;
>
> Replace those 2 lines with "goto out;".
>
>> + }
>> + }
>> + }
>
> here, add:
>
> ts = NULL;
> out:
>
> That way, you can use "ts" as the loop iteration variable.
>
> This whole patch rather assumes that all DT nodes can identify their
> exposed thermal sensors using an index in a single DT cell. That's not
> very flexible. All other DT bindings work like this:
>
> Provider of a service indicates how many DT cells are in the object
> (GPIO, IRQ, thermal sensors) specifier:
>
> sensor1: lm90 at 1c {
> ...
> #thermal-sensor-cells = <1>;
> };
>
> Each consumer of a service imports it by referencing it:
>
> thermal-zone {
> ...
> sensors = <&sensor1 0>;
> };
>
> The driver for LM90 provides an "of_xlate" function which receives a
> struct of_phandle_args and outputs/returns whatever Linux-internal
> identification/representation of the object is required. For example, see:
>
>> include/linux/pwm.h:161: struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
>
> This allows each providing object's DT binding to define its own value
> of #thermal-sensor-cells, as suited for its own requirements, and allows
> each driver to implement the mapping from DT to internal ID in whatever
> way is necessary.
>
> Now, many bindings/drivers might just end up using a common simple
> implementation. That's why functions such as of_pwm_simple_xlate() or
> of_gpio_simple_xlate() exist.
It looks like the "of_xlate" can handle the sensor identification.
I'm not familiar with this function, I will look into it and try to use.
Thanks for your comments.
Wei.
>
next prev parent reply other threads:[~2013-02-20 10:36 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 11:30 [RFC PATCH 0/9] Support for tegra30 thermal Wei Ni
2013-02-18 11:30 ` [RFC PATCH 1/9] ARM: dt: t30 cardhu: add dt entry for lm90 Wei Ni
2013-02-19 3:28 ` Alex Courbot
2013-02-19 9:52 ` Wei Ni
2013-02-19 22:48 ` Stephen Warren
2013-02-18 11:30 ` [RFC PATCH 2/9] hwmon: (lm90) split set&show temp as common codes Wei Ni
2013-02-18 22:29 ` Matthew Longnecker
2013-02-19 9:48 ` Wei Ni
2013-02-19 3:31 ` [lm-sensors] " Guenter Roeck
2013-02-19 10:00 ` Wei Ni
2013-02-19 22:56 ` Stephen Warren
2013-02-20 12:31 ` Wei Ni
2013-02-18 11:30 ` [RFC PATCH 3/9] hwmon: (lm90) add support to handle irq Wei Ni
2013-02-19 3:34 ` [lm-sensors] " Guenter Roeck
2013-02-19 10:43 ` Wei Ni
2013-02-19 23:00 ` Stephen Warren
2013-02-20 3:27 ` Alex Courbot
2013-02-20 10:27 ` Wei Ni
2013-02-18 11:30 ` [RFC PATCH 4/9] hwmon: (lm90) use macros for the indexes of temp8 and temp11 Wei Ni
2013-02-19 5:39 ` Alex Courbot
2013-02-19 9:58 ` Wei Ni
2013-02-19 23:02 ` Stephen Warren
2013-02-20 10:29 ` Wei Ni
2013-02-18 11:30 ` [RFC PATCH 5/9] Thermal: Support using dt node to get sensor Wei Ni
2013-02-19 23:12 ` Stephen Warren
2013-02-20 10:36 ` Wei Ni [this message]
2013-02-18 11:30 ` [RFC PATCH 6/9] hwmon: (lm90) Register to the thermal framework Wei Ni
2013-02-19 3:42 ` [lm-sensors] " Guenter Roeck
2013-02-19 10:47 ` Wei Ni
2013-02-19 5:22 ` Alex Courbot
2013-02-19 10:58 ` Wei Ni
2013-02-19 23:18 ` Stephen Warren
2013-02-20 10:40 ` Wei Ni
2013-02-18 11:30 ` [RFC PATCH 7/9] thermal: tegra30: add tegra30 thermal driver Wei Ni
2013-02-19 23:48 ` Stephen Warren
2013-02-20 12:23 ` Wei Ni
2013-02-19 23:56 ` Russell King - ARM Linux
2013-02-20 12:29 ` Wei Ni
2013-02-18 11:30 ` [RFC PATCH 8/9] ARM: dt: t30 cardhu: add dt entry for " Wei Ni
2013-02-19 3:42 ` Alex Courbot
2013-02-19 9:56 ` Wei Ni
2013-02-19 23:28 ` Stephen Warren
2013-02-20 11:53 ` Wei Ni
2013-02-20 17:18 ` Stephen Warren
2013-02-18 11:30 ` [RFC PATCH 9/9] ARM: tegra: defconfig: enable thermal framework Wei Ni
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