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}