1// SPDX-License-Identifier: GPL-2.0-or-later
  2
  3/* Platform profile sysfs interface */
  4
  5#include <linux/acpi.h>
  6#include <linux/bits.h>
  7#include <linux/init.h>
  8#include <linux/mutex.h>
  9#include <linux/platform_profile.h>
 10#include <linux/sysfs.h>
 11
 12static struct platform_profile_handler *cur_profile;
 13static DEFINE_MUTEX(profile_lock);
 14
 15static const char * const profile_names[] = {
 16	[PLATFORM_PROFILE_LOW_POWER] = "low-power",
 17	[PLATFORM_PROFILE_COOL] = "cool",
 18	[PLATFORM_PROFILE_QUIET] = "quiet",
 19	[PLATFORM_PROFILE_BALANCED] = "balanced",
 20	[PLATFORM_PROFILE_BALANCED_PERFORMANCE] = "balanced-performance",
 21	[PLATFORM_PROFILE_PERFORMANCE] = "performance",
 22};
 23static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);
 24
 25static ssize_t platform_profile_choices_show(struct device *dev,
 26					struct device_attribute *attr,
 27					char *buf)
 28{
 29	int len = 0;
 30	int err, i;
 31
 32	err = mutex_lock_interruptible(&profile_lock);
 33	if (err)
 34		return err;
 35
 36	if (!cur_profile) {
 37		mutex_unlock(&profile_lock);
 38		return -ENODEV;
 39	}
 40
 41	for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
 42		if (len == 0)
 43			len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
 44		else
 45			len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
 46	}
 47	len += sysfs_emit_at(buf, len, "\n");
 48	mutex_unlock(&profile_lock);
 49	return len;
 50}
 51
 52static ssize_t platform_profile_show(struct device *dev,
 53					struct device_attribute *attr,
 54					char *buf)
 55{
 56	enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
 57	int err;
 58
 59	err = mutex_lock_interruptible(&profile_lock);
 60	if (err)
 61		return err;
 62
 63	if (!cur_profile) {
 64		mutex_unlock(&profile_lock);
 65		return -ENODEV;
 66	}
 67
 68	err = cur_profile->profile_get(cur_profile, &profile);
 69	mutex_unlock(&profile_lock);
 70	if (err)
 71		return err;
 72
 73	/* Check that profile is valid index */
 74	if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
 75		return -EIO;
 76
 77	return sysfs_emit(buf, "%s\n", profile_names[profile]);
 78}
 79
 80static ssize_t platform_profile_store(struct device *dev,
 81			    struct device_attribute *attr,
 82			    const char *buf, size_t count)
 83{
 84	int err, i;
 85
 86	err = mutex_lock_interruptible(&profile_lock);
 87	if (err)
 88		return err;
 89
 90	if (!cur_profile) {
 91		mutex_unlock(&profile_lock);
 92		return -ENODEV;
 93	}
 94
 95	/* Scan for a matching profile */
 96	i = sysfs_match_string(profile_names, buf);
 97	if (i < 0) {
 98		mutex_unlock(&profile_lock);
 99		return -EINVAL;
100	}
101
102	/* Check that platform supports this profile choice */
103	if (!test_bit(i, cur_profile->choices)) {
104		mutex_unlock(&profile_lock);
105		return -EOPNOTSUPP;
106	}
107
108	err = cur_profile->profile_set(cur_profile, i);
109	if (!err)
110		sysfs_notify(acpi_kobj, NULL, "platform_profile");
111
112	mutex_unlock(&profile_lock);
113	if (err)
114		return err;
115	return count;
116}
117
118static DEVICE_ATTR_RO(platform_profile_choices);
119static DEVICE_ATTR_RW(platform_profile);
120
121static struct attribute *platform_profile_attrs[] = {
122	&dev_attr_platform_profile_choices.attr,
123	&dev_attr_platform_profile.attr,
124	NULL
125};
126
127static const struct attribute_group platform_profile_group = {
128	.attrs = platform_profile_attrs
129};
130
131void platform_profile_notify(void)
132{
133	if (!cur_profile)
134		return;
135	sysfs_notify(acpi_kobj, NULL, "platform_profile");
136}
137EXPORT_SYMBOL_GPL(platform_profile_notify);
138
139int platform_profile_register(struct platform_profile_handler *pprof)
140{
141	int err;
142
143	mutex_lock(&profile_lock);
144	/* We can only have one active profile */
145	if (cur_profile) {
146		mutex_unlock(&profile_lock);
147		return -EEXIST;
148	}
149
150	/* Sanity check the profile handler field are set */
151	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
152		!pprof->profile_set || !pprof->profile_get) {
153		mutex_unlock(&profile_lock);
154		return -EINVAL;
155	}
156
157	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
158	if (err) {
159		mutex_unlock(&profile_lock);
160		return err;
161	}
162
163	cur_profile = pprof;
164	mutex_unlock(&profile_lock);
165	return 0;
166}
167EXPORT_SYMBOL_GPL(platform_profile_register);
168
169int platform_profile_remove(void)
170{
171	sysfs_remove_group(acpi_kobj, &platform_profile_group);
172
173	mutex_lock(&profile_lock);
174	cur_profile = NULL;
175	mutex_unlock(&profile_lock);
176	return 0;
177}
178EXPORT_SYMBOL_GPL(platform_profile_remove);
179
180MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
181MODULE_LICENSE("GPL");