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 */
 15static 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
 24static 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
 29static 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
 50static 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
 59static 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 */
 68static 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
 77static 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
 82static 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
103static 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
112static 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 *
123intel_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 *
132intel_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 */
153void 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}