Re: [PATCH] of: thermal: Allow multiple devices to share cooling map

Eduardo Valentin
2018-08-06T18:05:59Z

Hello,

On Tue, Jul 17, 2018 at 04:24:16PM +0530, Viresh Kumar wrote:
> A cooling map entry may now contain a list of phandles and their
> arguments representing multiple devices which share the trip point.
>
> This patch updates the thermal OF core to parse them properly.

I am mostly fine with the patch idea, specially because we wont be
breaking existing DT blobs out there.

See comment below.

>
> Tested on Hikey960.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> This is a follow up patch to the DT bindings patchset:
>
> https://lkml.kernel.org/r/cover.1530766981.git.viresh.kumar@linaro.org
>
> drivers/thermal/of-thermal.c | 140 +++++++++++++++++++++++++----------
> 1 file changed, 102 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
> index 977a8307fbb1..79c06c4c861b 100644
> --- a/drivers/thermal/of-thermal.c
> +++ b/drivers/thermal/of-thermal.c
> @@ -19,22 +19,33 @@
> /*** Private data structures to represent thermal device tree data ***/
>
> /**
> - * struct __thermal_bind_param - a match between trip and cooling device
> + * struct __thermal_cooling_bind_param - a cooling device for a trip point
> * @cooling_device: a pointer to identify the referred cooling device
> - * @trip_id: the trip point index
> - * @usage: the percentage (from 0 to 100) of cooling contribution
> * @min: minimum cooling state used at this trip point
> * @max: maximum cooling state used at this trip point
> */
>
> -struct __thermal_bind_params {
> +struct __thermal_cooling_bind_param {
> struct device_node *cooling_device;
> - unsigned int trip_id;
> - unsigned int usage;
> unsigned long min;
> unsigned long max;
> };
>
> +/**
> + * struct __thermal_bind_param - a match between trip and cooling device
> + * @tcbp: a pointer to an array of cooling devices
> + * @count: number of elements in array
> + * @trip_id: the trip point index
> + * @usage: the percentage (from 0 to 100) of cooling contribution
> + */
> +
> +struct __thermal_bind_params {
> + struct __thermal_cooling_bind_param *tcbp;
> + unsigned int count;
> + unsigned int trip_id;
> + unsigned int usage;
> +};

Do you mind elaborating why you needed to do this split and adding a new
struct? More important, please describe in your commit message.

> +
> /**
> * struct __thermal_zone - internal representation of a thermal zone
> * @mode: current thermal zone device mode (enabled/disabled)
> @@ -192,25 +203,31 @@ static int of_thermal_bind(struct thermal_zone_device *thermal,
> struct thermal_cooling_device *cdev)
> {
> struct __thermal_zone *data = thermal->devdata;
> - int i;
> + struct __thermal_bind_params *tbp;
> + struct __thermal_cooling_bind_param *tcbp;
> + int i, j;
>
> if (!data || IS_ERR(data))
> return -ENODEV;
>
> /* find where to bind */
> for (i = 0; i < data->num_tbps; i++) {
> - struct __thermal_bind_params *tbp = data->tbps + i;
> + tbp = data->tbps + i;
>
> - if (tbp->cooling_device == cdev->np) {
> - int ret;
> + for (j = 0; j < tbp->count; j++) {
> + tcbp = tbp->tcbp + j;
>
> - ret = thermal_zone_bind_cooling_device(thermal,
> + if (tcbp->cooling_device == cdev->np) {
> + int ret;
> +
> + ret = thermal_zone_bind_cooling_device(thermal,
> tbp->trip_id, cdev,
> - tbp->max,
> - tbp->min,
> + tcbp->max,
> + tcbp->min,
> tbp->usage);
> - if (ret)
> - return ret;
> + if (ret)
> + return ret;
> + }
> }
> }
>
> @@ -221,22 +238,28 @@ static int of_thermal_unbind(struct thermal_zone_device *thermal,
> struct thermal_cooling_device *cdev)
> {
> struct __thermal_zone *data = thermal->devdata;
> - int i;
> + struct __thermal_bind_params *tbp;
> + struct __thermal_cooling_bind_param *tcbp;
> + int i, j;
>
> if (!data || IS_ERR(data))
> return -ENODEV;
>
> /* find where to unbind */
> for (i = 0; i < data->num_tbps; i++) {
> - struct __thermal_bind_params *tbp = data->tbps + i;
> + tbp = data->tbps + i;
> +
> + for (j = 0; j < tbp->count; j++) {
> + tcbp = tbp->tcbp + j;
>
> - if (tbp->cooling_device == cdev->np) {
> - int ret;
> + if (tcbp->cooling_device == cdev->np) {
> + int ret;
>
> - ret = thermal_zone_unbind_cooling_device(thermal,
> - tbp->trip_id, cdev);
> - if (ret)
> - return ret;
> + ret = thermal_zone_unbind_cooling_device(thermal,
> + tbp->trip_id, cdev);
> + if (ret)
> + return ret;
> + }
> }
> }
>
> @@ -652,8 +675,9 @@ static int thermal_of_populate_bind_params(struct device_node *np,
> int ntrips)
> {
> struct of_phandle_args cooling_spec;
> + struct __thermal_cooling_bind_param *__tcbp;
> struct device_node *trip;
> - int ret, i;
> + int ret, i, count;
> u32 prop;
>
> /* Default weight. Usage is optional */
> @@ -680,20 +704,44 @@ static int thermal_of_populate_bind_params(struct device_node *np,
> goto end;
> }
>
> - ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
> - 0, &cooling_spec);
> - if (ret < 0) {
> + count = of_count_phandle_with_args(np, "cooling-device",
> + "#cooling-cells");
> + if (!count) {
> pr_err("missing cooling_device property\n");

Probably the above error message deserves a better fit to the current
situation. Maybe:
+ pr_err("Add a cooling_device property with at least one device\n");

> goto end;
> }
> - __tbp->cooling_device = cooling_spec.np;
> - if (cooling_spec.args_count >= 2) { /* at least min and max */
> - __tbp->min = cooling_spec.args[0];
> - __tbp->max = cooling_spec.args[1];
> - } else {
> - pr_err("wrong reference to cooling device, missing limits\n");
> +
> + __tcbp = kcalloc(count, sizeof(*__tcbp), GFP_KERNEL);
> + if (!__tcbp)
> + goto end;
> +
> + for (i = 0; i < count; i++) {
> + ret = of_parse_phandle_with_args(np, "cooling-device",
> + "#cooling-cells", i, &cooling_spec);
> + if (ret < 0) {
> + pr_err("missing cooling_device property\n");

Here is a wrongly written cooling_device phandle, no?

> + goto free_tcbp;
> + }
> +
> + __tcbp[i].cooling_device = cooling_spec.np;
> +
> + if (cooling_spec.args_count >= 2) { /* at least min and max */
> + __tcbp[i].min = cooling_spec.args[0];
> + __tcbp[i].max = cooling_spec.args[1];
> + } else {
> + pr_err("wrong reference to cooling device, missing limits\n");
> + }
> }
>
> + __tbp->tcbp= __tcbp;
> + __tbp->count = count;
> +
> + goto end;
> +
> +free_tcbp:
> + for (i = i - 1; i >= 0; i--)
> + of_node_put(__tcbp[i].cooling_device);
> + kfree(__tcbp);
> end:
> of_node_put(trip);
>
> @@ -900,8 +948,16 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
> return tz;
>
> free_tbps:
> - for (i = i - 1; i >= 0; i--)
> - of_node_put(tz->tbps[i].cooling_device);
> + for (i = i - 1; i >= 0; i--) {
> + struct __thermal_bind_params *tbp = tz->tbps + i;
> + int j;
> +
> + for (j = 0; j < tbp->count; j++)
> + of_node_put(tbp->tcbp[j].cooling_device);
> +
> + kfree(tbp->tcbp);
> + }
> +
> kfree(tz->tbps);
> free_trips:
> for (i = 0; i < tz->ntrips; i++)
> @@ -917,10 +973,18 @@ __init *thermal_of_build_thermal_zone(struct device_node *np)
>
> static inline void of_thermal_free_zone(struct __thermal_zone *tz)
> {
> - int i;
> + struct __thermal_bind_params *tbp;
> + int i, j;
> +
> + for (i = 0; i < tz->num_tbps; i++) {
> + tbp = tz->tbps + i;
> +
> + for (j = 0; j < tbp->count; j++)
> + of_node_put(tbp->tcbp[j].cooling_device);
> +
> + kfree(tbp->tcbp);
> + }
>
> - for (i = 0; i < tz->num_tbps; i++)
> - of_node_put(tz->tbps[i].cooling_device);
> kfree(tz->tbps);
> for (i = 0; i < tz->ntrips; i++)
> of_node_put(tz->trips[i].np);
> --
> 2.18.0.rc1.242.g61856ae69a2c
>