// SPDX-License-Identifier: GPL-2.0-or-later
/*
* fbsysfs.c - framebuffer device class and attributes
*
* Copyright (c) 2004 James Simmons <[email protected]>
*/
#include <linux/console.h>
#include <linux/fb.h>
#include <linux/fbcon.h>
#include <linux/major.h>
#include "fb_internal.h"
#define FB_SYSFS_FLAG_ATTR 1
static int activate(struct fb_info *fb_info, struct fb_var_screeninfo *var)
{
int err;
var->activate |= FB_ACTIVATE_FORCE;
console_lock();
lock_fb_info(fb_info);
err = fb_set_var(fb_info, var);
if (!err)
fbcon_update_vcs(fb_info, var->activate & FB_ACTIVATE_ALL);
unlock_fb_info(fb_info);
console_unlock();
if (err)
return err;
return 0;
}
static int mode_string(char *buf, unsigned int offset,
const struct fb_videomode *mode)
{
char m = 'U';
char v = 'p';
if (mode->flag & FB_MODE_IS_DETAILED)
m = 'D';
if (mode->flag & FB_MODE_IS_VESA)
m = 'V';
if (mode->flag & FB_MODE_IS_STANDARD)
m = 'S';
if (mode->vmode & FB_VMODE_INTERLACED)
v = 'i';
if (mode->vmode & FB_VMODE_DOUBLE)
v = 'd';
return snprintf(&buf[offset], PAGE_SIZE - offset, "%c:%dx%d%c-%d\n",
m, mode->xres, mode->yres, v, mode->refresh);
}
static ssize_t store_mode(struct device *device, struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
char mstr[100];
struct fb_var_screeninfo var;
struct fb_modelist *modelist;
struct fb_videomode *mode;
size_t i;
int err;
memset(&var, 0, sizeof(var));
list_for_each_entry(modelist, &fb_info->modelist, list) {
mode = &modelist->mode;
i = mode_string(mstr, 0, mode);
if (strncmp(mstr, buf, max(count, i)) == 0) {
var = fb_info->var;
fb_videomode_to_var(&var, mode);
if ((err = activate(fb_info, &var)))
return err;
fb_info->mode = mode;
return count;
}
}
return -EINVAL;
}
static ssize_t show_mode(struct device *device, struct device_attribute *attr,
char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
if (!fb_info->mode)
return 0;
return mode_string(buf, 0, fb_info->mode);
}
static ssize_t store_modes(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
LIST_HEAD(old_list);
int i = count / sizeof(struct fb_videomode);
if (i * sizeof(struct fb_videomode) != count)
return -EINVAL;
console_lock();
lock_fb_info(fb_info);
list_splice(&fb_info->modelist, &old_list);
fb_videomode_to_modelist((const struct fb_videomode *)buf, i,
&fb_info->modelist);
if (fb_new_modelist(fb_info)) {
fb_destroy_modelist(&fb_info->modelist);
list_splice(&old_list, &fb_info->modelist);
} else
fb_destroy_modelist(&old_list);
unlock_fb_info(fb_info);
console_unlock();
return 0;
}
static ssize_t show_modes(struct device *device, struct device_attribute *attr,
char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
unsigned int i;
struct fb_modelist *modelist;
const struct fb_videomode *mode;
i = 0;
list_for_each_entry(modelist, &fb_info->modelist, list) {
mode = &modelist->mode;
i += mode_string(buf, i, mode);
}
return i;
}
static ssize_t store_bpp(struct device *device, struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
struct fb_var_screeninfo var;
char ** last = NULL;
int err;
var = fb_info->var;
var.bits_per_pixel = simple_strtoul(buf, last, 0);
if ((err = activate(fb_info, &var)))
return err;
return count;
}
static ssize_t show_bpp(struct device *device, struct device_attribute *attr,
char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
return sysfs_emit(buf, "%d\n", fb_info->var.bits_per_pixel);
}
static ssize_t store_rotate(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
struct fb_var_screeninfo var;
char **last = NULL;
int err;
var = fb_info->var;
var.rotate = simple_strtoul(buf, last, 0);
if ((err = activate(fb_info, &var)))
return err;
return count;
}
static ssize_t show_rotate(struct device *device,
struct device_attribute *attr, char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
return sysfs_emit(buf, "%d\n", fb_info->var.rotate);
}
static ssize_t store_virtual(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
struct fb_var_screeninfo var;
char *last = NULL;
int err;
var = fb_info->var;
var.xres_virtual = simple_strtoul(buf, &last, 0);
last++;
if (last - buf >= count)
return -EINVAL;
var.yres_virtual = simple_strtoul(last, &last, 0);
if ((err = activate(fb_info, &var)))
return err;
return count;
}
static ssize_t show_virtual(struct device *device,
struct device_attribute *attr, char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
return sysfs_emit(buf, "%d,%d\n", fb_info->var.xres_virtual,
fb_info->var.yres_virtual);
}
static ssize_t show_stride(struct device *device,
struct device_attribute *attr, char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
return sysfs_emit(buf, "%d\n", fb_info->fix.line_length);
}
static ssize_t store_blank(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
char *last = NULL;
int err, arg;
arg = simple_strtoul(buf, &last, 0);
console_lock();
err = fb_blank(fb_info, arg);
/* might again call into fb_blank */
fbcon_fb_blanked(fb_info, arg);
console_unlock();
if (err < 0)
return err;
return count;
}
static ssize_t show_blank(struct device *device,
struct device_attribute *attr, char *buf)
{
// struct fb_info *fb_info = dev_get_drvdata(device);
return 0;
}
static ssize_t store_console(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
// struct fb_info *fb_info = dev_get_drvdata(device);
return 0;
}
static ssize_t show_console(struct device *device,
struct device_attribute *attr, char *buf)
{
// struct fb_info *fb_info = dev_get_drvdata(device);
return 0;
}
static ssize_t store_cursor(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
// struct fb_info *fb_info = dev_get_drvdata(device);
return 0;
}
static ssize_t show_cursor(struct device *device,
struct device_attribute *attr, char *buf)
{
// struct fb_info *fb_info = dev_get_drvdata(device);
return 0;
}
static ssize_t store_pan(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
struct fb_var_screeninfo var;
char *last = NULL;
int err;
var = fb_info->var;
var.xoffset = simple_strtoul(buf, &last, 0);
last++;
if (last - buf >= count)
return -EINVAL;
var.yoffset = simple_strtoul(last, &last, 0);
console_lock();
err = fb_pan_display(fb_info, &var);
console_unlock();
if (err < 0)
return err;
return count;
}
static ssize_t show_pan(struct device *device,
struct device_attribute *attr, char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
return sysfs_emit(buf, "%d,%d\n", fb_info->var.xoffset,
fb_info->var.yoffset);
}
static ssize_t show_name(struct device *device,
struct device_attribute *attr, char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
return sysfs_emit(buf, "%s\n", fb_info->fix.id);
}
static ssize_t store_fbstate(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
u32 state;
char *last = NULL;
state = simple_strtoul(buf, &last, 0);
console_lock();
lock_fb_info(fb_info);
fb_set_suspend(fb_info, (int)state);
unlock_fb_info(fb_info);
console_unlock();
return count;
}
static ssize_t show_fbstate(struct device *device,
struct device_attribute *attr, char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
return sysfs_emit(buf, "%d\n", fb_info->state);
}
#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
static ssize_t store_bl_curve(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct fb_info *fb_info = dev_get_drvdata(device);
u8 tmp_curve[FB_BACKLIGHT_LEVELS];
unsigned int i;
/* Some drivers don't use framebuffer_alloc(), but those also
* don't have backlights.
*/
if (!fb_info || !fb_info->bl_dev)
return -ENODEV;
if (count != (FB_BACKLIGHT_LEVELS / 8 * 24))
return -EINVAL;
for (i = 0; i < (FB_BACKLIGHT_LEVELS / 8); ++i)
if (sscanf(&buf[i * 24],
"%2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx\n",
&tmp_curve[i * 8 + 0],
&tmp_curve[i * 8 + 1],
&tmp_curve[i * 8 + 2],
&tmp_curve[i * 8 + 3],
&tmp_curve[i * 8 + 4],
&tmp_curve[i * 8 + 5],
&tmp_curve[i * 8 + 6],
&tmp_curve[i * 8 + 7]) != 8)
return -EINVAL;
/* If there has been an error in the input data, we won't
* reach this loop.
*/
mutex_lock(&fb_info->bl_curve_mutex);
for (i = 0; i < FB_BACKLIGHT_LEVELS; ++i)
fb_info->bl_curve[i] = tmp_curve[i];
mutex_unlock(&fb_info->bl_curve_mutex);
return count;
}
static ssize_t show_bl_curve(struct device *device,
struct device_attribute *attr, char *buf)
{
struct fb_info *fb_info = dev_get_drvdata(device);
ssize_t len = 0;
unsigned int i;
/* Some drivers don't use framebuffer_alloc(), but those also
* don't have backlights.
*/
if (!fb_info || !fb_info->bl_dev)
return -ENODEV;
mutex_lock(&fb_info->bl_curve_mutex);
for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8)
len += scnprintf(&buf[len], PAGE_SIZE - len, "%8ph\n",
fb_info->bl_curve + i);
mutex_unlock(&fb_info->bl_curve_mutex);
return len;
}
#endif
/* When cmap is added back in it should be a binary attribute
* not a text one. Consideration should also be given to converting
* fbdev to use configfs instead of sysfs */
static struct device_attribute device_attrs[] = {
__ATTR(bits_per_pixel, S_IRUGO|S_IWUSR, show_bpp, store_bpp),
__ATTR(blank, S_IRUGO|S_IWUSR, show_blank, store_blank),
__ATTR(console, S_IRUGO|S_IWUSR, show_console, store_console),
__ATTR(cursor, S_IRUGO|S_IWUSR, show_cursor, store_cursor),
__ATTR(mode, S_IRUGO|S_IWUSR, show_mode, store_mode),
__ATTR(modes, S_IRUGO|S_IWUSR, show_modes, store_modes),
__ATTR(pan, S_IRUGO|S_IWUSR, show_pan, store_pan),
__ATTR(virtual_size, S_IRUGO|S_IWUSR, show_virtual, store_virtual),
__ATTR(name, S_IRUGO, show_name, NULL),
__ATTR(stride, S_IRUGO, show_stride, NULL),
__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
__ATTR(state, S_IRUGO|S_IWUSR, show_fbstate, store_fbstate),
#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
__ATTR(bl_curve, S_IRUGO|S_IWUSR, show_bl_curve, store_bl_curve),
#endif
};
static int fb_init_device(struct fb_info *fb_info)
{
int i, error = 0;
dev_set_drvdata(fb_info->dev, fb_info);
fb_info->class_flag |= FB_SYSFS_FLAG_ATTR;
for (i = 0; i < ARRAY_SIZE(device_attrs); i++) {
error = device_create_file(fb_info->dev, &device_attrs[i]);
if (error)
break;
}
if (error) {
while (--i >= 0)
device_remove_file(fb_info->dev, &device_attrs[i]);
fb_info->class_flag &= ~FB_SYSFS_FLAG_ATTR;
}
return 0;
}
static void fb_cleanup_device(struct fb_info *fb_info)
{
unsigned int i;
if (fb_info->class_flag & FB_SYSFS_FLAG_ATTR) {
for (i = 0; i < ARRAY_SIZE(device_attrs); i++)
device_remove_file(fb_info->dev, &device_attrs[i]);
fb_info->class_flag &= ~FB_SYSFS_FLAG_ATTR;
}
}
int fb_device_create(struct fb_info *fb_info)
{
int node = fb_info->node;
dev_t devt = MKDEV(FB_MAJOR, node);
int ret;
fb_info->dev = device_create(fb_class, fb_info->device, devt, NULL, "fb%d", node);
if (IS_ERR(fb_info->dev)) {
/* Not fatal */
ret = PTR_ERR(fb_info->dev);
pr_warn("Unable to create device for framebuffer %d; error %d\n", node, ret);
fb_info->dev = NULL;
} else {
fb_init_device(fb_info);
}
return 0;
}
void fb_device_destroy(struct fb_info *fb_info)
{
dev_t devt = MKDEV(FB_MAJOR, fb_info->node);
if (!fb_info->dev)
return;
fb_cleanup_device(fb_info);
device_destroy(fb_class, devt);
fb_info->dev = NULL;
}
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