Hi Guenter,
Agreed with the suggestion with regards to fan profile support.
Looked at thermal driver and further planning to implement required changes in thermal core instead of pwm-fan driver.
Dropping the current series.
Thanks & Regards,
Sandipan
> -----Original Message-----
> From: Guenter Roeck <groeck7@xxxxxxxxx> On Behalf Of Guenter Roeck
> Sent: Tuesday, June 2, 2020 7:58 PM
> To: Sandipan Patra <spatra@xxxxxxxxxx>
> Cc: Thierry Reding <treding@xxxxxxxxxx>; Jonathan Hunter
> <jonathanh@xxxxxxxxxx>; kamil@xxxxxxxxx; jdelvare@xxxxxxxx;
> robh+dt@xxxxxxxxxx; u.kleine-koenig@xxxxxxxxxxxxxx; Bibek Basu
> <bbasu@xxxxxxxxxx>; Bitan Biswas <bbiswas@xxxxxxxxxx>; Krishna Yarlagadda
> <kyarlagadda@xxxxxxxxxx>; linux-pwm@xxxxxxxxxxxxxxx; linux-
> hwmon@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> tegra@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH V2 1/2] hwmon: pwm-fan: Add profile support and add
> remove module support
>
> External email: Use caution opening links or attachments
>
>
> On Mon, Jun 01, 2020 at 11:49:13AM +0530, Sandipan Patra wrote:
> > Add support for profiles mode settings.
> > This allows different fan settings for trip point temp/hyst/pwm.
> > Tegra194 has multiple fan-profiles support.
> >
> > Signed-off-by: Sandipan Patra <spatra@xxxxxxxxxx>
>
> The subject says "remove module support". What is this supposed to be about ?
>
> The code adds support for multiple cooling "profiles" but, unless I am really
> missing something, no means to actually select a profile.
> This adds a lot of complexity to the code with zero value.
>
> Either case, and I may have mentioned this before, functionality like this should
> really reside in the thermal core and not in individual drivers.
>
> > ---
> >
> > PATCH V2:
> > Cleaned pwm_fan_remove support as it is not required.
> >
> > drivers/hwmon/pwm-fan.c | 92
> > ++++++++++++++++++++++++++++++++++++++++++-------
> > 1 file changed, 80 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index
> > 30b7b3e..1d2a416 100644
> > --- a/drivers/hwmon/pwm-fan.c
> > +++ b/drivers/hwmon/pwm-fan.c
> > @@ -3,8 +3,10 @@
> > * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
> > *
> > * Copyright (c) 2014 Samsung Electronics Co., Ltd.
> > + * Copyright (c) 2020, NVIDIA Corporation.
> > *
> > * Author: Kamil Debski <k.debski@xxxxxxxxxxx>
> > + * Author: Sandipan Patra <spatra@xxxxxxxxxx>
>
> You can not claim authorship for a driver by adding a few lines of code to it.
>
> > */
> >
> > #include <linux/hwmon.h>
> > @@ -21,6 +23,8 @@
> > #include <linux/timer.h>
> >
> > #define MAX_PWM 255
> > +/* Based on OF max device tree node name length */
> > +#define MAX_PROFILE_NAME_LENGTH 31
> >
> > struct pwm_fan_ctx {
> > struct mutex lock;
> > @@ -38,6 +42,12 @@ struct pwm_fan_ctx {
> > unsigned int pwm_fan_state;
> > unsigned int pwm_fan_max_state;
> > unsigned int *pwm_fan_cooling_levels;
> > +
> > + unsigned int pwm_fan_profiles;
> > + const char **fan_profile_names;
> > + unsigned int **fan_profile_cooling_levels;
> > + unsigned int fan_current_profile;
> > +
> > struct thermal_cooling_device *cdev; };
> >
> > @@ -227,28 +237,86 @@ static int pwm_fan_of_get_cooling_data(struct
> device *dev,
> > struct pwm_fan_ctx *ctx) {
> > struct device_node *np = dev->of_node;
> > + struct device_node *base_profile = NULL;
> > + struct device_node *profile_np = NULL;
> > + const char *default_profile = NULL;
> > int num, i, ret;
> >
> > - if (!of_find_property(np, "cooling-levels", NULL))
> > - return 0;
> > + num = of_property_count_u32_elems(np, "cooling-levels");
> > + if (num <= 0) {
> > + base_profile = of_get_child_by_name(np, "profiles");
>
> You can not just add new properties like this without documenting it and getting
> approval by devicetree maintainers.
>
> Guenter
>
> > + if (!base_profile) {
> > + dev_err(dev, "Wrong Data\n");
> > + return -EINVAL;
> > + }
> > + }
> > +
> > + if (base_profile) {
> > + ctx->pwm_fan_profiles =
> > + of_get_available_child_count(base_profile);
> >
> > - ret = of_property_count_u32_elems(np, "cooling-levels");
> > - if (ret <= 0) {
> > - dev_err(dev, "Wrong data!\n");
> > - return ret ? : -EINVAL;
> > + if (ctx->pwm_fan_profiles <= 0) {
> > + dev_err(dev, "Profiles used but not defined\n");
> > + return -EINVAL;
> > + }
> > +
> > + ctx->fan_profile_names = devm_kzalloc(dev,
> > + sizeof(const char *) * ctx->pwm_fan_profiles,
> > + GFP_KERNEL);
> > + ctx->fan_profile_cooling_levels = devm_kzalloc(dev,
> > + sizeof(int *) * ctx->pwm_fan_profiles,
> > + GFP_KERNEL);
> > +
> > + if (!ctx->fan_profile_names
> > + || !ctx->fan_profile_cooling_levels)
> > + return -ENOMEM;
> > +
> > + ctx->fan_current_profile = 0;
> > + i = 0;
> > + for_each_available_child_of_node(base_profile, profile_np) {
> > + num = of_property_count_u32_elems(profile_np,
> > + "cooling-levels");
> > + if (num <= 0) {
> > + dev_err(dev, "No data in cooling-levels inside profile
> node!\n");
> > + return -EINVAL;
> > + }
> > +
> > + of_property_read_string(profile_np, "name",
> > + &ctx->fan_profile_names[i]);
> > + if (default_profile &&
> > + !strncmp(default_profile,
> > + ctx->fan_profile_names[i],
> > + MAX_PROFILE_NAME_LENGTH))
> > + ctx->fan_current_profile = i;
> > +
> > + ctx->fan_profile_cooling_levels[i] =
> > + devm_kzalloc(dev, sizeof(int) * num,
> > + GFP_KERNEL);
> > + if (!ctx->fan_profile_cooling_levels[i])
> > + return -ENOMEM;
> > +
> > + of_property_read_u32_array(profile_np, "cooling-levels",
> > + ctx->fan_profile_cooling_levels[i], num);
> > + i++;
> > + }
> > }
> >
> > - num = ret;
> > ctx->pwm_fan_cooling_levels = devm_kcalloc(dev, num, sizeof(u32),
> > GFP_KERNEL);
> > if (!ctx->pwm_fan_cooling_levels)
> > return -ENOMEM;
> >
> > - ret = of_property_read_u32_array(np, "cooling-levels",
> > - ctx->pwm_fan_cooling_levels, num);
> > - if (ret) {
> > - dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
> > - return ret;
> > + if (base_profile) {
> > + memcpy(ctx->pwm_fan_cooling_levels,
> > + ctx->fan_profile_cooling_levels[ctx->fan_current_profile],
> > + num);
> > + } else {
> > + ret = of_property_read_u32_array(np, "cooling-levels",
> > + ctx->pwm_fan_cooling_levels, num);
> > + if (ret) {
> > + dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
> > + return -EINVAL;
> > + }
> > }
> >
> > for (i = 0; i < num; i++) {
