[PATCH 1/2] hwmon: pwm-fan: Add profile support and add remove module support

From: Sandipan Patra
Date: Tue May 26 2020 - 01:06:20 EST


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 | 112 ++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 100 insertions(+), 12 deletions(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 30b7b3e..26db589 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",
--
2.7.4