diff options
Diffstat (limited to 'drivers/video/display/display-sysfs.c')
| -rw-r--r-- | drivers/video/display/display-sysfs.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/drivers/video/display/display-sysfs.c b/drivers/video/display/display-sysfs.c new file mode 100644 index 0000000..39c27b6 --- /dev/null +++ b/drivers/video/display/display-sysfs.c @@ -0,0 +1,217 @@ +/* + * display-sysfs.c - Display output driver sysfs interface + * + * Copyright (C) 2007 James Simmons <jsimmons@infradead.org> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ +#include <linux/module.h> +#include <linux/display.h> +#include <linux/ctype.h> +#include <linux/idr.h> +#include <linux/err.h> + +static ssize_t display_show_name(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct display_device *dsp = dev_get_drvdata(dev); + return snprintf(buf, PAGE_SIZE, "%s\n", dsp->name); +} + +static ssize_t display_show_type(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct display_device *dsp = dev_get_drvdata(dev); + return snprintf(buf, PAGE_SIZE, "%s\n", dsp->type); +} + +static ssize_t display_show_contrast(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct display_device *dsp = dev_get_drvdata(dev); + ssize_t rc = -ENXIO; + + mutex_lock(&dsp->lock); + if (likely(dsp->driver) && dsp->driver->get_contrast) + rc = sprintf(buf, "%d\n", dsp->driver->get_contrast(dsp)); + mutex_unlock(&dsp->lock); + return rc; +} + +static ssize_t display_store_contrast(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct display_device *dsp = dev_get_drvdata(dev); + ssize_t ret = -EINVAL, size; + int contrast; + char *endp; + + contrast = simple_strtoul(buf, &endp, 0); + size = endp - buf; + + if (*endp && isspace(*endp)) + size++; + + if (size != count) + return ret; + + mutex_lock(&dsp->lock); + if (likely(dsp->driver && dsp->driver->set_contrast)) { + pr_debug("display: set contrast to %d\n", contrast); + dsp->driver->set_contrast(dsp, contrast); + ret = count; + } + mutex_unlock(&dsp->lock); + return ret; +} + +static ssize_t display_show_max_contrast(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct display_device *dsp = dev_get_drvdata(dev); + ssize_t rc = -ENXIO; + + mutex_lock(&dsp->lock); + if (likely(dsp->driver)) + rc = sprintf(buf, "%d\n", dsp->driver->max_contrast); + mutex_unlock(&dsp->lock); + return rc; +} + +static struct device_attribute display_attrs[] = { + __ATTR(name, S_IRUGO, display_show_name, NULL), + __ATTR(type, S_IRUGO, display_show_type, NULL), + __ATTR(contrast, S_IRUGO | S_IWUSR, display_show_contrast, display_store_contrast), + __ATTR(max_contrast, S_IRUGO, display_show_max_contrast, NULL), +}; + +static int display_suspend(struct device *dev, pm_message_t state) +{ + struct display_device *dsp = dev_get_drvdata(dev); + + mutex_lock(&dsp->lock); + if (likely(dsp->driver->suspend)) + dsp->driver->suspend(dsp, state); + mutex_unlock(&dsp->lock); + return 0; +}; + +static int display_resume(struct device *dev) +{ + struct display_device *dsp = dev_get_drvdata(dev); + + mutex_lock(&dsp->lock); + if (likely(dsp->driver->resume)) + dsp->driver->resume(dsp); + mutex_unlock(&dsp->lock); + return 0; +}; + +static struct mutex allocated_dsp_lock; +static DEFINE_IDR(allocated_dsp); +struct class *display_class; + +struct display_device *display_device_register(struct display_driver *driver, + struct device *parent, void *devdata) +{ + struct display_device *new_dev = NULL; + int ret = -EINVAL; + + if (unlikely(!driver)) + return ERR_PTR(ret); + + mutex_lock(&allocated_dsp_lock); + ret = idr_pre_get(&allocated_dsp, GFP_KERNEL); + mutex_unlock(&allocated_dsp_lock); + if (!ret) + return ERR_PTR(ret); + + new_dev = kzalloc(sizeof(struct display_device), GFP_KERNEL); + if (likely(new_dev) && unlikely(driver->probe(new_dev, devdata))) { + // Reserve the index for this display + mutex_lock(&allocated_dsp_lock); + ret = idr_get_new(&allocated_dsp, new_dev, &new_dev->idx); + mutex_unlock(&allocated_dsp_lock); + + if (!ret) { + new_dev->dev = device_create(display_class, parent, 0, + "display%d", new_dev->idx); + if (!IS_ERR(new_dev->dev)) { + dev_set_drvdata(new_dev->dev, new_dev); + new_dev->parent = parent; + new_dev->driver = driver; + mutex_init(&new_dev->lock); + return new_dev; + } + mutex_lock(&allocated_dsp_lock); + idr_remove(&allocated_dsp, new_dev->idx); + mutex_unlock(&allocated_dsp_lock); + ret = -EINVAL; + } + } + kfree(new_dev); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(display_device_register); + +void display_device_unregister(struct display_device *ddev) +{ + if (!ddev) + return; + // Free device + mutex_lock(&ddev->lock); + device_unregister(ddev->dev); + mutex_unlock(&ddev->lock); + // Mark device index as avaliable + mutex_lock(&allocated_dsp_lock); + idr_remove(&allocated_dsp, ddev->idx); + mutex_unlock(&allocated_dsp_lock); + kfree(ddev); +} +EXPORT_SYMBOL(display_device_unregister); + +static int __init display_class_init(void) +{ + display_class = class_create(THIS_MODULE, "display"); + if (IS_ERR(display_class)) { + printk(KERN_ERR "Failed to create display class\n"); + display_class = NULL; + return -EINVAL; + } + display_class->dev_attrs = display_attrs; + display_class->suspend = display_suspend; + display_class->resume = display_resume; + mutex_init(&allocated_dsp_lock); + return 0; +} + +static void __exit display_class_exit(void) +{ + class_destroy(display_class); +} + +module_init(display_class_init); +module_exit(display_class_exit); + +MODULE_DESCRIPTION("Display Hardware handling"); +MODULE_AUTHOR("James Simmons <jsimmons@infradead.org>"); +MODULE_LICENSE("GPL"); + |