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