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path: root/drivers/video/display/display-sysfs.c
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Diffstat (limited to 'drivers/video/display/display-sysfs.c')
-rw-r--r--drivers/video/display/display-sysfs.c217
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 00000000000..39c27b604cc
--- /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");
+