1// SPDX-License-Identifier: MIT
2/*
3 * Copyright �� 2023 Intel Corporation
4 */
5
6#include <linux/debugfs.h>
7#include <linux/kernel.h>
8
9#include <drm/drm_drv.h>
10
11#include "intel_display_debugfs_params.h"
12#include "i915_drv.h"
13#include "intel_display_params.h"
14
15/* int param */
16static int intel_display_param_int_show(struct seq_file *m, void *data)
17{
18	int *value = m->private;
19
20	seq_printf(m, "%d\n", *value);
21
22	return 0;
23}
24
25static int intel_display_param_int_open(struct inode *inode, struct file *file)
26{
27	return single_open(file, intel_display_param_int_show, inode->i_private);
28}
29
30static ssize_t intel_display_param_int_write(struct file *file,
31					     const char __user *ubuf, size_t len,
32					     loff_t *offp)
33{
34	struct seq_file *m = file->private_data;
35	int *value = m->private;
36	int ret;
37
38	ret = kstrtoint_from_user(ubuf, len, 0, value);
39	if (ret) {
40		/* support boolean values too */
41		bool b;
42
43		ret = kstrtobool_from_user(ubuf, len, &b);
44		if (!ret)
45			*value = b;
46	}
47
48	return ret ?: len;
49}
50
51static const struct file_operations intel_display_param_int_fops = {
52	.owner = THIS_MODULE,
53	.open = intel_display_param_int_open,
54	.read = seq_read,
55	.write = intel_display_param_int_write,
56	.llseek = default_llseek,
57	.release = single_release,
58};
59
60static const struct file_operations intel_display_param_int_fops_ro = {
61	.owner = THIS_MODULE,
62	.open = intel_display_param_int_open,
63	.read = seq_read,
64	.llseek = default_llseek,
65	.release = single_release,
66};
67
68/* unsigned int param */
69static int intel_display_param_uint_show(struct seq_file *m, void *data)
70{
71	unsigned int *value = m->private;
72
73	seq_printf(m, "%u\n", *value);
74
75	return 0;
76}
77
78static int intel_display_param_uint_open(struct inode *inode, struct file *file)
79{
80	return single_open(file, intel_display_param_uint_show, inode->i_private);
81}
82
83static ssize_t intel_display_param_uint_write(struct file *file,
84					      const char __user *ubuf, size_t len,
85					      loff_t *offp)
86{
87	struct seq_file *m = file->private_data;
88	unsigned int *value = m->private;
89	int ret;
90
91	ret = kstrtouint_from_user(ubuf, len, 0, value);
92	if (ret) {
93		/* support boolean values too */
94		bool b;
95
96		ret = kstrtobool_from_user(ubuf, len, &b);
97		if (!ret)
98			*value = b;
99	}
100
101	return ret ?: len;
102}
103
104static const struct file_operations intel_display_param_uint_fops = {
105	.owner = THIS_MODULE,
106	.open = intel_display_param_uint_open,
107	.read = seq_read,
108	.write = intel_display_param_uint_write,
109	.llseek = default_llseek,
110	.release = single_release,
111};
112
113static const struct file_operations intel_display_param_uint_fops_ro = {
114	.owner = THIS_MODULE,
115	.open = intel_display_param_uint_open,
116	.read = seq_read,
117	.llseek = default_llseek,
118	.release = single_release,
119};
120
121#define RO(mode) (((mode) & 0222) == 0)
122
123__maybe_unused static struct dentry *
124intel_display_debugfs_create_int(const char *name, umode_t mode,
125			struct dentry *parent, int *value)
126{
127	return debugfs_create_file_unsafe(name, mode, parent, value,
128					  RO(mode) ? &intel_display_param_int_fops_ro :
129					  &intel_display_param_int_fops);
130}
131
132__maybe_unused static struct dentry *
133intel_display_debugfs_create_uint(const char *name, umode_t mode,
134			 struct dentry *parent, unsigned int *value)
135{
136	return debugfs_create_file_unsafe(name, mode, parent, value,
137					  RO(mode) ? &intel_display_param_uint_fops_ro :
138					  &intel_display_param_uint_fops);
139}
140
141#define _intel_display_param_create_file(parent, name, mode, valp)	\
142	do {								\
143		if (mode)						\
144			_Generic(valp,					\
145				 bool * : debugfs_create_bool,		\
146				 int * : intel_display_debugfs_create_int, \
147				 unsigned int * : intel_display_debugfs_create_uint, \
148				 unsigned long * : debugfs_create_ulong, \
149				 char ** : debugfs_create_str) \
150				(name, mode, parent, valp);		\
151	} while (0)
152
153/* add a subdirectory with files for each intel display param */
154void intel_display_debugfs_params(struct drm_i915_private *i915)
155{
156	struct drm_minor *minor = i915->drm.primary;
157	struct dentry *dir;
158	char dirname[16];
159
160	snprintf(dirname, sizeof(dirname), "%s_params", i915->drm.driver->name);
161	dir = debugfs_lookup(dirname, minor->debugfs_root);
162	if (!dir)
163		dir = debugfs_create_dir(dirname, minor->debugfs_root);
164	if (IS_ERR(dir))
165		return;
166
167	/*
168	 * Note: We could create files for params needing special handling
169	 * here. Set mode in params to 0 to skip the generic create file, or
170	 * just let the generic create file fail silently with -EEXIST.
171	 */
172
173#define REGISTER(T, x, unused, mode, ...) _intel_display_param_create_file( \
174		dir, #x, mode, &i915->display.params.x);
175	INTEL_DISPLAY_PARAMS_FOR_EACH(REGISTER);
176#undef REGISTER
177}
178