RE: [PATCH 2/2] hwmon: pwm-fan: Add profile support and add remove module support

From: Sandipan Patra
Date: Mon May 04 2020 - 03:15:11 EST


Gentle reminder.

> -----Original Message-----
> From: Sandipan Patra <spatra@xxxxxxxxxx>
> Sent: Friday, April 17, 2020 7:03 PM
> To: Thierry Reding <treding@xxxxxxxxxx>; robh+dt@xxxxxxxxxx; u.kleine-
> koenig@xxxxxxxxxxxxxx; Jonathan Hunter <jonathanh@xxxxxxxxxx>
> Cc: Bibek Basu <bbasu@xxxxxxxxxx>; Bitan Biswas <bbiswas@xxxxxxxxxx>;
> linux-pwm@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> tegra@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Sandipan Patra
> <spatra@xxxxxxxxxx>
> Subject: [PATCH 2/2] hwmon: pwm-fan: Add profile support and add remove
> module support
>
> This change has 2 parts:
> 1. Add support for profiles mode settings.
> This allows different fan settings for trip point temp/hyst/pwm.
> T194 has multiple fan-profiles support.
>
> 2. Add pwm-fan remove support. This is essential since the config is
> tristate capable.
>
> Signed-off-by: Sandipan Patra <spatra@xxxxxxxxxx>
> ---
> drivers/hwmon/pwm-fan.c | 113
> +++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 101 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index
> 30b7b3e..6332ed8 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>
> */
>
> #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");
> + 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);
> +
> + if (ctx->pwm_fan_profiles <= 0) {
> + dev_err(dev, "Profiles used but not defined\n");
> + return -EINVAL;
> + }
>
> - ret = of_property_count_u32_elems(np, "cooling-levels");
> - if (ret <= 0) {
> - dev_err(dev, "Wrong data!\n");
> - return ret ? : -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++) {
> @@ -390,6 +458,25 @@ static int pwm_fan_probe(struct platform_device
> *pdev)
> return 0;
> }
>
> +static int pwm_fan_remove(struct platform_device *pdev) {
> + struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
> + struct pwm_args args;
> +
> + if (!ctx)
> + return -EINVAL;
> +
> + if (IS_ENABLED(CONFIG_THERMAL))
> + thermal_cooling_device_unregister(ctx->cdev);
> +
> + pwm_get_args(ctx->pwm, &args);
> + pwm_config(ctx->pwm, 0, args.period);
> + pwm_disable(ctx->pwm);
> +
> + return 0;
> +}
> +
> +
> static int pwm_fan_disable(struct device *dev) {
> struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); @@ -465,6 +552,7
> @@ MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
>
> static struct platform_driver pwm_fan_driver = {
> .probe = pwm_fan_probe,
> + .remove = pwm_fan_remove,
> .shutdown = pwm_fan_shutdown,
> .driver = {
> .name = "pwm-fan",
> @@ -476,6 +564,7 @@ static struct platform_driver pwm_fan_driver = {
> module_platform_driver(pwm_fan_driver);
>
> MODULE_AUTHOR("Kamil Debski <k.debski@xxxxxxxxxxx>");
> +MODULE_AUTHOR("Sandipan Patra <spatra@xxxxxxxxxx>");
> MODULE_ALIAS("platform:pwm-fan");
> MODULE_DESCRIPTION("PWM FAN driver");
> MODULE_LICENSE("GPL");
> --
> 2.7.4