Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * pwm-fan.c - Hwmon driver for fans connected to PWM lines.
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
 *
 * Author: Kamil Debski <k.debski@samsung.com>
 */
 
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/regulator/consumer.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>
#include <linux/timer.h>
#include <soc/rockchip/rockchip_system_monitor.h>
 
#define MAX_PWM 255
 
struct thermal_trips {
<------>int temp;
<------>int state;
};
 
struct pwm_fan_ctx {
<------>struct mutex lock;
<------>struct pwm_device *pwm;
<------>struct regulator *reg_en;
 
<------>int irq;
<------>atomic_t pulses;
<------>unsigned int rpm;
<------>u8 pulses_per_revolution;
<------>ktime_t sample_start;
<------>struct timer_list rpm_timer;
 
<------>unsigned int pwm_value;
<------>unsigned int pwm_fan_state;
<------>unsigned int pwm_fan_max_state;
<------>unsigned int *pwm_fan_cooling_levels;
<------>struct thermal_cooling_device *cdev;
<------>struct notifier_block thermal_nb;
<------>struct thermal_trips *thermal_trips;
<------>bool thermal_notifier_is_ok;
};
 
/* This handler assumes self resetting edge triggered interrupt. */
static irqreturn_t pulse_handler(int irq, void *dev_id)
{
<------>struct pwm_fan_ctx *ctx = dev_id;
 
<------>atomic_inc(&ctx->pulses);
 
<------>return IRQ_HANDLED;
}
 
static void sample_timer(struct timer_list *t)
{
<------>struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer);
<------>unsigned int delta = ktime_ms_delta(ktime_get(), ctx->sample_start);
<------>int pulses;
 
<------>if (delta) {
<------><------>pulses = atomic_read(&ctx->pulses);
<------><------>atomic_sub(pulses, &ctx->pulses);
<------><------>ctx->rpm = (unsigned int)(pulses * 1000 * 60) /
<------><------><------>(ctx->pulses_per_revolution * delta);
 
<------><------>ctx->sample_start = ktime_get();
<------>}
 
<------>mod_timer(&ctx->rpm_timer, jiffies + HZ);
}
 
static int  __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
{
<------>unsigned long period;
<------>int ret = 0;
<------>struct pwm_state state = { };
 
<------>mutex_lock(&ctx->lock);
<------>if (ctx->pwm_value == pwm)
<------><------>goto exit_set_pwm_err;
 
<------>pwm_init_state(ctx->pwm, &state);
<------>period = ctx->pwm->args.period;
<------>state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
<------>state.enabled = pwm ? true : false;
 
<------>ret = pwm_apply_state(ctx->pwm, &state);
<------>if (!ret)
<------><------>ctx->pwm_value = pwm;
exit_set_pwm_err:
<------>mutex_unlock(&ctx->lock);
<------>return ret;
}
 
static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
{
<------>int i;
 
<------>for (i = 0; i < ctx->pwm_fan_max_state; ++i)
<------><------>if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
<------><------><------>break;
 
<------>ctx->pwm_fan_state = i;
}
 
static ssize_t pwm_store(struct device *dev, struct device_attribute *attr,
<------><------><------> const char *buf, size_t count)
{
<------>struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
<------>unsigned long pwm;
<------>int ret;
 
<------>if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
<------><------>return -EINVAL;
 
<------>ret = __set_pwm(ctx, pwm);
<------>if (ret)
<------><------>return ret;
 
<------>pwm_fan_update_state(ctx, pwm);
<------>return count;
}
 
static ssize_t pwm_show(struct device *dev, struct device_attribute *attr,
<------><------><------>char *buf)
{
<------>struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 
<------>return sprintf(buf, "%u\n", ctx->pwm_value);
}
 
static ssize_t rpm_show(struct device *dev,
<------><------><------>struct device_attribute *attr, char *buf)
{
<------>struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 
<------>return sprintf(buf, "%u\n", ctx->rpm);
}
 
static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0);
 
static struct attribute *pwm_fan_attrs[] = {
<------>&sensor_dev_attr_pwm1.dev_attr.attr,
<------>&sensor_dev_attr_fan1_input.dev_attr.attr,
<------>NULL,
};
 
static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a,
<------><------><------><------>     int n)
{
<------>struct device *dev = container_of(kobj, struct device, kobj);
<------>struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
 
<------>/* Hide fan_input in case no interrupt is available  */
<------>if (n == 1 && ctx->irq <= 0)
<------><------>return 0;
 
<------>return a->mode;
}
 
static const struct attribute_group pwm_fan_group = {
<------>.attrs = pwm_fan_attrs,
<------>.is_visible = pwm_fan_attrs_visible,
};
 
static const struct attribute_group *pwm_fan_groups[] = {
<------>&pwm_fan_group,
<------>NULL,
};
 
/* thermal cooling device callbacks */
static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
<------><------><------><------> unsigned long *state)
{
<------>struct pwm_fan_ctx *ctx = cdev->devdata;
 
<------>if (!ctx)
<------><------>return -EINVAL;
 
<------>*state = ctx->pwm_fan_max_state;
 
<------>return 0;
}
 
static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
<------><------><------><------> unsigned long *state)
{
<------>struct pwm_fan_ctx *ctx = cdev->devdata;
 
<------>if (!ctx)
<------><------>return -EINVAL;
 
<------>*state = ctx->pwm_fan_state;
 
<------>return 0;
}
 
static int
pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
{
<------>struct pwm_fan_ctx *ctx = cdev->devdata;
<------>int ret;
 
<------>if (!ctx || (state > ctx->pwm_fan_max_state))
<------><------>return -EINVAL;
 
<------>if (state == ctx->pwm_fan_state)
<------><------>return 0;
 
<------>ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
<------>if (ret) {
<------><------>dev_err(&cdev->device, "Cannot set pwm!\n");
<------><------>return ret;
<------>}
 
<------>ctx->pwm_fan_state = state;
 
<------>return ret;
}
 
static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
<------>.get_max_state = pwm_fan_get_max_state,
<------>.get_cur_state = pwm_fan_get_cur_state,
<------>.set_cur_state = pwm_fan_set_cur_state,
};
 
static int pwm_fan_of_get_cooling_data(struct device *dev,
<------><------><------><------>       struct pwm_fan_ctx *ctx)
{
<------>struct device_node *np = dev->of_node;
<------>int num, i, ret;
 
<------>if (!of_find_property(np, "cooling-levels", NULL))
<------><------>return 0;
 
<------>ret = of_property_count_u32_elems(np, "cooling-levels");
<------>if (ret <= 0) {
<------><------>dev_err(dev, "Wrong data!\n");
<------><------>return ret ? : -EINVAL;
<------>}
 
<------>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;
<------>}
 
<------>for (i = 0; i < num; i++) {
<------><------>if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
<------><------><------>dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
<------><------><------><------>ctx->pwm_fan_cooling_levels[i], MAX_PWM);
<------><------><------>return -EINVAL;
<------><------>}
<------>}
 
<------>ctx->pwm_fan_max_state = num - 1;
 
<------>return 0;
}
 
static void pwm_fan_regulator_disable(void *data)
{
<------>regulator_disable(data);
}
 
static void pwm_fan_pwm_disable(void *__ctx)
{
<------>struct pwm_fan_ctx *ctx = __ctx;
<------>pwm_disable(ctx->pwm);
<------>del_timer_sync(&ctx->rpm_timer);
}
 
static int pwm_fan_get_thermal_trips(struct device *dev, char *porp_name,
<------><------><------><------>     struct thermal_trips **trips)
{
<------>struct device_node *np = dev->of_node;
<------>struct thermal_trips *thermal_trips;
<------>const struct property *prop;
<------>int count, i;
 
<------>prop = of_find_property(np, porp_name, NULL);
<------>if (!prop)
<------><------>return -EINVAL;
<------>if (!prop->value)
<------><------>return -ENODATA;
<------>count = of_property_count_u32_elems(np, porp_name);
<------>if (count < 0)
<------><------>return -EINVAL;
<------>if (count % 2)
<------><------>return -EINVAL;
<------>thermal_trips = devm_kzalloc(dev,
<------><------><------><------>     sizeof(*thermal_trips) * (count / 2 + 1),
<------><------><------><------>     GFP_KERNEL);
<------>if (!thermal_trips)
<------><------>return -ENOMEM;
 
<------>for (i = 0; i < count / 2; i++) {
<------><------>of_property_read_u32_index(np, porp_name, 2 * i,
<------><------><------><------><------>   &thermal_trips[i].temp);
<------><------>of_property_read_u32_index(np, porp_name, 2 * i + 1,
<------><------><------><------><------>   &thermal_trips[i].state);
<------>}
<------>thermal_trips[i].temp = 0;
<------>thermal_trips[i].state = INT_MAX;
 
<------>*trips = thermal_trips;
 
<------>return 0;
}
 
static int pwm_fan_temp_to_state(struct pwm_fan_ctx *ctx, int temp)
{
<------>struct thermal_trips *trips = ctx->thermal_trips;
<------>int i, state = 0;
 
<------>for (i = 0; trips[i].state != INT_MAX; i++) {
<------><------>if (temp >= trips[i].temp)
<------><------><------>state = trips[i].state;
<------>}
 
<------>return state;
}
 
static int pwm_fan_thermal_notifier_call(struct notifier_block *nb,
<------><------><------><------><------> unsigned long event, void *data)
{
<------>struct pwm_fan_ctx *ctx = container_of(nb, struct pwm_fan_ctx, thermal_nb);
<------>struct system_monitor_event_data *event_data = data;
<------>int state, ret;
 
<------>if (event != SYSTEM_MONITOR_CHANGE_TEMP)
<------><------>return NOTIFY_OK;
 
<------>state = pwm_fan_temp_to_state(ctx, event_data->temp);
<------>if (state > ctx->pwm_fan_max_state)
<------><------>return NOTIFY_BAD;
<------>if (state == ctx->pwm_fan_state)
<------><------>return NOTIFY_OK;
 
<------>ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
<------>if (ret)
<------><------>return NOTIFY_BAD;
 
<------>ctx->pwm_fan_state = state;
 
<------>return NOTIFY_OK;
}
 
static int pwm_fan_register_thermal_notifier(struct device *dev,
<------><------><------><------><------>     struct pwm_fan_ctx *ctx)
{
<------>if (pwm_fan_get_thermal_trips(dev, "rockchip,temp-trips",
<------><------><------><------>      &ctx->thermal_trips))
<------><------>return -EINVAL;
 
<------>ctx->thermal_nb.notifier_call = pwm_fan_thermal_notifier_call;
 
<------>return rockchip_system_monitor_register_notifier(&ctx->thermal_nb);
}
 
static int pwm_fan_probe(struct platform_device *pdev)
{
<------>struct thermal_cooling_device *cdev;
<------>struct device *dev = &pdev->dev;
<------>struct pwm_fan_ctx *ctx;
<------>struct device *hwmon;
<------>int ret;
<------>struct pwm_state state = { };
<------>u32 ppr = 2;
 
<------>ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
<------>if (!ctx)
<------><------>return -ENOMEM;
 
<------>mutex_init(&ctx->lock);
 
<------>ctx->pwm = devm_of_pwm_get(dev, dev->of_node, NULL);
<------>if (IS_ERR(ctx->pwm))
<------><------>return dev_err_probe(dev, PTR_ERR(ctx->pwm), "Could not get PWM\n");
 
<------>platform_set_drvdata(pdev, ctx);
 
<------>ctx->irq = platform_get_irq_optional(pdev, 0);
<------>if (ctx->irq == -EPROBE_DEFER)
<------><------>return ctx->irq;
 
<------>ctx->reg_en = devm_regulator_get_optional(dev, "fan");
<------>if (IS_ERR(ctx->reg_en)) {
<------><------>if (PTR_ERR(ctx->reg_en) != -ENODEV)
<------><------><------>return PTR_ERR(ctx->reg_en);
 
<------><------>ctx->reg_en = NULL;
<------>} else {
<------><------>ret = regulator_enable(ctx->reg_en);
<------><------>if (ret) {
<------><------><------>dev_err(dev, "Failed to enable fan supply: %d\n", ret);
<------><------><------>return ret;
<------><------>}
<------><------>ret = devm_add_action_or_reset(dev, pwm_fan_regulator_disable,
<------><------><------><------><------>       ctx->reg_en);
<------><------>if (ret)
<------><------><------>return ret;
<------>}
 
<------>ctx->pwm_value = MAX_PWM;
 
<------>pwm_init_state(ctx->pwm, &state);
<------>/*
<------> * __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned
<------> * long. Check this here to prevent the fan running at a too low
<------> * frequency.
<------> */
<------>if (state.period > ULONG_MAX / MAX_PWM + 1) {
<------><------>dev_err(dev, "Configured period too big\n");
<------><------>return -EINVAL;
<------>}
 
<------>/* Set duty cycle to maximum allowed and enable PWM output */
<------>state.duty_cycle = ctx->pwm->args.period - 1;
<------>state.enabled = true;
 
<------>ret = pwm_apply_state(ctx->pwm, &state);
<------>if (ret) {
<------><------>dev_err(dev, "Failed to configure PWM: %d\n", ret);
<------><------>return ret;
<------>}
<------>timer_setup(&ctx->rpm_timer, sample_timer, 0);
<------>ret = devm_add_action_or_reset(dev, pwm_fan_pwm_disable, ctx);
<------>if (ret)
<------><------>return ret;
 
<------>of_property_read_u32(dev->of_node, "pulses-per-revolution", &ppr);
<------>ctx->pulses_per_revolution = ppr;
<------>if (!ctx->pulses_per_revolution) {
<------><------>dev_err(dev, "pulses-per-revolution can't be zero.\n");
<------><------>return -EINVAL;
<------>}
 
<------>if (ctx->irq > 0) {
<------><------>ret = devm_request_irq(dev, ctx->irq, pulse_handler, 0,
<------><------><------><------>       pdev->name, ctx);
<------><------>if (ret) {
<------><------><------>dev_err(dev, "Failed to request interrupt: %d\n", ret);
<------><------><------>return ret;
<------><------>}
<------><------>ctx->sample_start = ktime_get();
<------><------>mod_timer(&ctx->rpm_timer, jiffies + HZ);
<------>}
 
<------>hwmon = devm_hwmon_device_register_with_groups(dev, "pwmfan",
<------><------><------><------><------><------>       ctx, pwm_fan_groups);
<------>if (IS_ERR(hwmon)) {
<------><------>dev_err(dev, "Failed to register hwmon device\n");
<------><------>return PTR_ERR(hwmon);
<------>}
 
<------>ret = pwm_fan_of_get_cooling_data(dev, ctx);
<------>if (ret)
<------><------>return ret;
 
<------>ctx->pwm_fan_state = ctx->pwm_fan_max_state;
<------>if (IS_REACHABLE(CONFIG_ROCKCHIP_SYSTEM_MONITOR) &&
<------>    of_find_property(dev->of_node, "rockchip,temp-trips", NULL)) {
<------><------>ret = pwm_fan_register_thermal_notifier(dev, ctx);
<------><------>if (ret)
<------><------><------>dev_err(dev, "Failed to register thermal notifier: %d\n", ret);
<------><------>else
<------><------><------>ctx->thermal_notifier_is_ok = true;
<------><------>return 0;
<------>}
<------>if (IS_ENABLED(CONFIG_THERMAL)) {
<------><------>cdev = devm_thermal_of_cooling_device_register(dev,
<------><------><------>dev->of_node, "pwm-fan", ctx, &pwm_fan_cooling_ops);
<------><------>if (IS_ERR(cdev)) {
<------><------><------>ret = PTR_ERR(cdev);
<------><------><------>dev_err(dev,
<------><------><------><------>"Failed to register pwm-fan as cooling device: %d\n",
<------><------><------><------>ret);
<------><------><------>return ret;
<------><------>}
<------><------>ctx->cdev = cdev;
<------><------>thermal_cdev_update(cdev);
<------>}
 
<------>return 0;
}
 
static int pwm_fan_disable(struct device *dev)
{
<------>struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
<------>struct pwm_args args;
<------>int ret;
 
<------>pwm_get_args(ctx->pwm, &args);
 
<------>if (ctx->pwm_value || ctx->thermal_notifier_is_ok) {
<------><------>ret = pwm_config(ctx->pwm, 0, args.period);
<------><------>if (ret < 0)
<------><------><------>return ret;
 
<------><------>pwm_disable(ctx->pwm);
<------>}
 
<------>if (ctx->reg_en) {
<------><------>ret = regulator_disable(ctx->reg_en);
<------><------>if (ret) {
<------><------><------>dev_err(dev, "Failed to disable fan supply: %d\n", ret);
<------><------><------>return ret;
<------><------>}
<------>}
 
<------>return 0;
}
 
static void pwm_fan_shutdown(struct platform_device *pdev)
{
<------>pwm_fan_disable(&pdev->dev);
}
 
#ifdef CONFIG_PM_SLEEP
static int pwm_fan_suspend(struct device *dev)
{
<------>return pwm_fan_disable(dev);
}
 
static int pwm_fan_resume(struct device *dev)
{
<------>struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
<------>struct pwm_args pargs;
<------>unsigned long duty;
<------>int ret;
 
<------>if (ctx->reg_en) {
<------><------>ret = regulator_enable(ctx->reg_en);
<------><------>if (ret) {
<------><------><------>dev_err(dev, "Failed to enable fan supply: %d\n", ret);
<------><------><------>return ret;
<------><------>}
<------>}
 
<------>if (ctx->pwm_value == 0 && !ctx->thermal_notifier_is_ok)
<------><------>return 0;
 
<------>pwm_get_args(ctx->pwm, &pargs);
<------>duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
<------>ret = pwm_config(ctx->pwm, duty, pargs.period);
<------>if (ret)
<------><------>return ret;
<------>return pwm_enable(ctx->pwm);
}
#endif
 
static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
 
static const struct of_device_id of_pwm_fan_match[] = {
<------>{ .compatible = "pwm-fan", },
<------>{},
};
MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
 
static struct platform_driver pwm_fan_driver = {
<------>.probe		= pwm_fan_probe,
<------>.shutdown	= pwm_fan_shutdown,
<------>.driver	= {
<------><------>.name		= "pwm-fan",
<------><------>.pm		= &pwm_fan_pm,
<------><------>.of_match_table	= of_pwm_fan_match,
<------>},
};
 
module_platform_driver(pwm_fan_driver);
 
MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
MODULE_ALIAS("platform:pwm-fan");
MODULE_DESCRIPTION("PWM FAN driver");
MODULE_LICENSE("GPL");