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![Bartlomiej Zolnierkiewicz](/assets/img/avatar_default.png)
Switch pwm-fan driver to new atomic PWM API. Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
341 lines
7.6 KiB
C
341 lines
7.6 KiB
C
/*
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* pwm-fan.c - Hwmon driver for fans connected to PWM lines.
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*
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* Copyright (c) 2014 Samsung Electronics Co., Ltd.
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*
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* Author: Kamil Debski <k.debski@samsung.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pwm.h>
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#include <linux/sysfs.h>
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#include <linux/thermal.h>
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#define MAX_PWM 255
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struct pwm_fan_ctx {
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struct mutex lock;
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struct pwm_device *pwm;
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unsigned int pwm_value;
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unsigned int pwm_fan_state;
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unsigned int pwm_fan_max_state;
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unsigned int *pwm_fan_cooling_levels;
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struct thermal_cooling_device *cdev;
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};
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static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm)
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{
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unsigned long period;
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int ret = 0;
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struct pwm_state state = { };
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mutex_lock(&ctx->lock);
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if (ctx->pwm_value == pwm)
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goto exit_set_pwm_err;
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pwm_init_state(ctx->pwm, &state);
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period = ctx->pwm->args.period;
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state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM);
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state.enabled = pwm ? true : false;
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ret = pwm_apply_state(ctx->pwm, &state);
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if (!ret)
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ctx->pwm_value = pwm;
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exit_set_pwm_err:
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mutex_unlock(&ctx->lock);
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return ret;
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}
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static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
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{
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int i;
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for (i = 0; i < ctx->pwm_fan_max_state; ++i)
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if (pwm < ctx->pwm_fan_cooling_levels[i + 1])
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break;
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ctx->pwm_fan_state = i;
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}
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static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
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unsigned long pwm;
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int ret;
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if (kstrtoul(buf, 10, &pwm) || pwm > MAX_PWM)
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return -EINVAL;
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ret = __set_pwm(ctx, pwm);
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if (ret)
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return ret;
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pwm_fan_update_state(ctx, pwm);
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return count;
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}
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static ssize_t show_pwm(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
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return sprintf(buf, "%u\n", ctx->pwm_value);
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}
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static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm, 0);
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static struct attribute *pwm_fan_attrs[] = {
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&sensor_dev_attr_pwm1.dev_attr.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(pwm_fan);
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/* thermal cooling device callbacks */
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static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
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unsigned long *state)
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{
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struct pwm_fan_ctx *ctx = cdev->devdata;
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if (!ctx)
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return -EINVAL;
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*state = ctx->pwm_fan_max_state;
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return 0;
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}
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static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
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unsigned long *state)
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{
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struct pwm_fan_ctx *ctx = cdev->devdata;
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if (!ctx)
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return -EINVAL;
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*state = ctx->pwm_fan_state;
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return 0;
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}
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static int
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pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
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{
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struct pwm_fan_ctx *ctx = cdev->devdata;
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int ret;
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if (!ctx || (state > ctx->pwm_fan_max_state))
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return -EINVAL;
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if (state == ctx->pwm_fan_state)
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return 0;
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ret = __set_pwm(ctx, ctx->pwm_fan_cooling_levels[state]);
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if (ret) {
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dev_err(&cdev->device, "Cannot set pwm!\n");
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return ret;
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}
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ctx->pwm_fan_state = state;
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return ret;
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}
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static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
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.get_max_state = pwm_fan_get_max_state,
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.get_cur_state = pwm_fan_get_cur_state,
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.set_cur_state = pwm_fan_set_cur_state,
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};
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static int pwm_fan_of_get_cooling_data(struct device *dev,
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struct pwm_fan_ctx *ctx)
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{
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struct device_node *np = dev->of_node;
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int num, i, ret;
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if (!of_find_property(np, "cooling-levels", NULL))
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return 0;
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ret = of_property_count_u32_elems(np, "cooling-levels");
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if (ret <= 0) {
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dev_err(dev, "Wrong data!\n");
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return ret ? : -EINVAL;
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}
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num = ret;
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ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32),
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GFP_KERNEL);
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if (!ctx->pwm_fan_cooling_levels)
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return -ENOMEM;
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ret = of_property_read_u32_array(np, "cooling-levels",
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ctx->pwm_fan_cooling_levels, num);
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if (ret) {
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dev_err(dev, "Property 'cooling-levels' cannot be read!\n");
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return ret;
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}
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for (i = 0; i < num; i++) {
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if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) {
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dev_err(dev, "PWM fan state[%d]:%d > %d\n", i,
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ctx->pwm_fan_cooling_levels[i], MAX_PWM);
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return -EINVAL;
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}
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}
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ctx->pwm_fan_max_state = num - 1;
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return 0;
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}
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static int pwm_fan_probe(struct platform_device *pdev)
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{
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struct thermal_cooling_device *cdev;
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struct pwm_fan_ctx *ctx;
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struct device *hwmon;
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int ret;
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struct pwm_state state = { };
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ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
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if (!ctx)
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return -ENOMEM;
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mutex_init(&ctx->lock);
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ctx->pwm = devm_of_pwm_get(&pdev->dev, pdev->dev.of_node, NULL);
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if (IS_ERR(ctx->pwm)) {
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dev_err(&pdev->dev, "Could not get PWM\n");
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return PTR_ERR(ctx->pwm);
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}
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platform_set_drvdata(pdev, ctx);
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ctx->pwm_value = MAX_PWM;
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/* Set duty cycle to maximum allowed and enable PWM output */
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pwm_init_state(ctx->pwm, &state);
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state.duty_cycle = ctx->pwm->args.period - 1;
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state.enabled = true;
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ret = pwm_apply_state(ctx->pwm, &state);
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if (ret) {
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dev_err(&pdev->dev, "Failed to configure PWM\n");
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return ret;
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}
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hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan",
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ctx, pwm_fan_groups);
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if (IS_ERR(hwmon)) {
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dev_err(&pdev->dev, "Failed to register hwmon device\n");
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ret = PTR_ERR(hwmon);
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goto err_pwm_disable;
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}
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ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx);
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if (ret)
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return ret;
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ctx->pwm_fan_state = ctx->pwm_fan_max_state;
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if (IS_ENABLED(CONFIG_THERMAL)) {
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cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
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"pwm-fan", ctx,
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&pwm_fan_cooling_ops);
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if (IS_ERR(cdev)) {
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dev_err(&pdev->dev,
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"Failed to register pwm-fan as cooling device");
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ret = PTR_ERR(cdev);
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goto err_pwm_disable;
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}
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ctx->cdev = cdev;
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thermal_cdev_update(cdev);
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}
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return 0;
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err_pwm_disable:
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state.enabled = false;
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pwm_apply_state(ctx->pwm, &state);
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return ret;
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}
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static int pwm_fan_remove(struct platform_device *pdev)
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{
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struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev);
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thermal_cooling_device_unregister(ctx->cdev);
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if (ctx->pwm_value)
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pwm_disable(ctx->pwm);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int pwm_fan_suspend(struct device *dev)
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{
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struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
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if (ctx->pwm_value)
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pwm_disable(ctx->pwm);
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return 0;
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}
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static int pwm_fan_resume(struct device *dev)
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{
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struct pwm_fan_ctx *ctx = dev_get_drvdata(dev);
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struct pwm_args pargs;
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unsigned long duty;
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int ret;
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if (ctx->pwm_value == 0)
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return 0;
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pwm_get_args(ctx->pwm, &pargs);
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duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
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ret = pwm_config(ctx->pwm, duty, pargs.period);
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if (ret)
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return ret;
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return pwm_enable(ctx->pwm);
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}
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#endif
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static SIMPLE_DEV_PM_OPS(pwm_fan_pm, pwm_fan_suspend, pwm_fan_resume);
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static const struct of_device_id of_pwm_fan_match[] = {
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{ .compatible = "pwm-fan", },
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{},
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};
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MODULE_DEVICE_TABLE(of, of_pwm_fan_match);
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static struct platform_driver pwm_fan_driver = {
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.probe = pwm_fan_probe,
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.remove = pwm_fan_remove,
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.driver = {
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.name = "pwm-fan",
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.pm = &pwm_fan_pm,
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.of_match_table = of_pwm_fan_match,
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},
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};
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module_platform_driver(pwm_fan_driver);
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MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
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MODULE_ALIAS("platform:pwm-fan");
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MODULE_DESCRIPTION("PWM FAN driver");
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MODULE_LICENSE("GPL");
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