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 #include <drm/drm_file.h>
11
12 #include "intel_display_core.h"
13 #include "intel_display_debugfs_params.h"
14 #include "intel_display_params.h"
15
16 /* int param */
intel_display_param_int_show(struct seq_file * m,void * data)17 static int intel_display_param_int_show(struct seq_file *m, void *data)
18 {
19 int *value = m->private;
20
21 seq_printf(m, "%d\n", *value);
22
23 return 0;
24 }
25
intel_display_param_int_open(struct inode * inode,struct file * file)26 static int intel_display_param_int_open(struct inode *inode, struct file *file)
27 {
28 return single_open(file, intel_display_param_int_show, inode->i_private);
29 }
30
intel_display_param_int_write(struct file * file,const char __user * ubuf,size_t len,loff_t * offp)31 static ssize_t intel_display_param_int_write(struct file *file,
32 const char __user *ubuf, size_t len,
33 loff_t *offp)
34 {
35 struct seq_file *m = file->private_data;
36 int *value = m->private;
37 int ret;
38
39 ret = kstrtoint_from_user(ubuf, len, 0, value);
40 if (ret) {
41 /* support boolean values too */
42 bool b;
43
44 ret = kstrtobool_from_user(ubuf, len, &b);
45 if (!ret)
46 *value = b;
47 }
48
49 return ret ?: len;
50 }
51
52 static const struct file_operations intel_display_param_int_fops = {
53 .owner = THIS_MODULE,
54 .open = intel_display_param_int_open,
55 .read = seq_read,
56 .write = intel_display_param_int_write,
57 .llseek = default_llseek,
58 .release = single_release,
59 };
60
61 static const struct file_operations intel_display_param_int_fops_ro = {
62 .owner = THIS_MODULE,
63 .open = intel_display_param_int_open,
64 .read = seq_read,
65 .llseek = default_llseek,
66 .release = single_release,
67 };
68
69 /* unsigned int param */
intel_display_param_uint_show(struct seq_file * m,void * data)70 static int intel_display_param_uint_show(struct seq_file *m, void *data)
71 {
72 unsigned int *value = m->private;
73
74 seq_printf(m, "%u\n", *value);
75
76 return 0;
77 }
78
intel_display_param_uint_open(struct inode * inode,struct file * file)79 static int intel_display_param_uint_open(struct inode *inode, struct file *file)
80 {
81 return single_open(file, intel_display_param_uint_show, inode->i_private);
82 }
83
intel_display_param_uint_write(struct file * file,const char __user * ubuf,size_t len,loff_t * offp)84 static ssize_t intel_display_param_uint_write(struct file *file,
85 const char __user *ubuf, size_t len,
86 loff_t *offp)
87 {
88 struct seq_file *m = file->private_data;
89 unsigned int *value = m->private;
90 int ret;
91
92 ret = kstrtouint_from_user(ubuf, len, 0, value);
93 if (ret) {
94 /* support boolean values too */
95 bool b;
96
97 ret = kstrtobool_from_user(ubuf, len, &b);
98 if (!ret)
99 *value = b;
100 }
101
102 return ret ?: len;
103 }
104
105 static const struct file_operations intel_display_param_uint_fops = {
106 .owner = THIS_MODULE,
107 .open = intel_display_param_uint_open,
108 .read = seq_read,
109 .write = intel_display_param_uint_write,
110 .llseek = default_llseek,
111 .release = single_release,
112 };
113
114 static const struct file_operations intel_display_param_uint_fops_ro = {
115 .owner = THIS_MODULE,
116 .open = intel_display_param_uint_open,
117 .read = seq_read,
118 .llseek = default_llseek,
119 .release = single_release,
120 };
121
122 #define RO(mode) (((mode) & 0222) == 0)
123
124 __maybe_unused static struct dentry *
intel_display_debugfs_create_int(const char * name,umode_t mode,struct dentry * parent,int * value)125 intel_display_debugfs_create_int(const char *name, umode_t mode,
126 struct dentry *parent, int *value)
127 {
128 return debugfs_create_file_unsafe(name, mode, parent, value,
129 RO(mode) ? &intel_display_param_int_fops_ro :
130 &intel_display_param_int_fops);
131 }
132
133 __maybe_unused static struct dentry *
intel_display_debugfs_create_uint(const char * name,umode_t mode,struct dentry * parent,unsigned int * value)134 intel_display_debugfs_create_uint(const char *name, umode_t mode,
135 struct dentry *parent, unsigned int *value)
136 {
137 return debugfs_create_file_unsafe(name, mode, parent, value,
138 RO(mode) ? &intel_display_param_uint_fops_ro :
139 &intel_display_param_uint_fops);
140 }
141
142 #define _intel_display_param_create_file(parent, name, mode, valp) \
143 do { \
144 if (mode) \
145 _Generic(valp, \
146 bool * : debugfs_create_bool, \
147 int * : intel_display_debugfs_create_int, \
148 unsigned int * : intel_display_debugfs_create_uint, \
149 unsigned long * : debugfs_create_ulong, \
150 char ** : debugfs_create_str) \
151 (name, mode, parent, valp); \
152 } while (0)
153
154 /* add a subdirectory with files for each intel display param */
intel_display_debugfs_params(struct intel_display * display)155 void intel_display_debugfs_params(struct intel_display *display)
156 {
157 struct drm_minor *minor = display->drm->primary;
158 struct dentry *dir;
159 char dirname[16];
160
161 snprintf(dirname, sizeof(dirname), "%s_params", display->drm->driver->name);
162 dir = debugfs_lookup(dirname, minor->debugfs_root);
163 if (!dir)
164 dir = debugfs_create_dir(dirname, minor->debugfs_root);
165 if (IS_ERR(dir))
166 return;
167
168 /*
169 * Note: We could create files for params needing special handling
170 * here. Set mode in params to 0 to skip the generic create file, or
171 * just let the generic create file fail silently with -EEXIST.
172 */
173
174 #define REGISTER(T, x, unused, mode, ...) _intel_display_param_create_file( \
175 dir, #x, mode, &display->params.x);
176 INTEL_DISPLAY_PARAMS_FOR_EACH(REGISTER);
177 #undef REGISTER
178 }
179