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 */
intel_display_param_int_show(struct seq_file * m,void * data)16 static 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
intel_display_param_int_open(struct inode * inode,struct file * file)25 static 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
intel_display_param_int_write(struct file * file,const char __user * ubuf,size_t len,loff_t * offp)30 static 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
51 static 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
60 static 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 */
intel_display_param_uint_show(struct seq_file * m,void * data)69 static 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
intel_display_param_uint_open(struct inode * inode,struct file * file)78 static 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
intel_display_param_uint_write(struct file * file,const char __user * ubuf,size_t len,loff_t * offp)83 static 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
104 static 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
113 static 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 *
intel_display_debugfs_create_int(const char * name,umode_t mode,struct dentry * parent,int * value)124 intel_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 *
intel_display_debugfs_create_uint(const char * name,umode_t mode,struct dentry * parent,unsigned int * value)133 intel_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 */
intel_display_debugfs_params(struct intel_display * display)154 void intel_display_debugfs_params(struct intel_display *display)
155 {
156 struct drm_minor *minor = display->drm->primary;
157 struct dentry *dir;
158 char dirname[16];
159
160 snprintf(dirname, sizeof(dirname), "%s_params", display->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, &display->params.x);
175 INTEL_DISPLAY_PARAMS_FOR_EACH(REGISTER);
176 #undef REGISTER
177 }
178