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![Uwe Kleine-König](/assets/img/avatar_default.png)
Once device_register is called for a device its attributes might be accessed. As the callbacks of a lcd device's attributes make use of the lcd_ops, the respective member must be setup before calling device_register. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Lee Jones <lee.jones@linaro.org>
364 lines
8.7 KiB
C
364 lines
8.7 KiB
C
/*
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* LCD Lowlevel Control Abstraction
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*
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* Copyright (C) 2003,2004 Hewlett-Packard Company
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/lcd.h>
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#include <linux/notifier.h>
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#include <linux/ctype.h>
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#include <linux/err.h>
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#include <linux/fb.h>
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#include <linux/slab.h>
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#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
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defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
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/* This callback gets called when something important happens inside a
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* framebuffer driver. We're looking if that important event is blanking,
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* and if it is, we're switching lcd power as well ...
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*/
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static int fb_notifier_callback(struct notifier_block *self,
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unsigned long event, void *data)
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{
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struct lcd_device *ld;
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struct fb_event *evdata = data;
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/* If we aren't interested in this event, skip it immediately ... */
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switch (event) {
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case FB_EVENT_BLANK:
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case FB_EVENT_MODE_CHANGE:
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case FB_EVENT_MODE_CHANGE_ALL:
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case FB_EARLY_EVENT_BLANK:
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case FB_R_EARLY_EVENT_BLANK:
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break;
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default:
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return 0;
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}
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ld = container_of(self, struct lcd_device, fb_notif);
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if (!ld->ops)
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return 0;
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mutex_lock(&ld->ops_lock);
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if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) {
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if (event == FB_EVENT_BLANK) {
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if (ld->ops->set_power)
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ld->ops->set_power(ld, *(int *)evdata->data);
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} else if (event == FB_EARLY_EVENT_BLANK) {
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if (ld->ops->early_set_power)
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ld->ops->early_set_power(ld,
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*(int *)evdata->data);
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} else if (event == FB_R_EARLY_EVENT_BLANK) {
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if (ld->ops->r_early_set_power)
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ld->ops->r_early_set_power(ld,
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*(int *)evdata->data);
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} else {
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if (ld->ops->set_mode)
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ld->ops->set_mode(ld, evdata->data);
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}
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}
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mutex_unlock(&ld->ops_lock);
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return 0;
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}
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static int lcd_register_fb(struct lcd_device *ld)
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{
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memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
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ld->fb_notif.notifier_call = fb_notifier_callback;
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return fb_register_client(&ld->fb_notif);
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}
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static void lcd_unregister_fb(struct lcd_device *ld)
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{
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fb_unregister_client(&ld->fb_notif);
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}
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#else
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static int lcd_register_fb(struct lcd_device *ld)
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{
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return 0;
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}
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static inline void lcd_unregister_fb(struct lcd_device *ld)
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{
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}
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#endif /* CONFIG_FB */
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static ssize_t lcd_power_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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int rc;
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struct lcd_device *ld = to_lcd_device(dev);
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mutex_lock(&ld->ops_lock);
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if (ld->ops && ld->ops->get_power)
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rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
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else
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rc = -ENXIO;
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mutex_unlock(&ld->ops_lock);
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return rc;
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}
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static ssize_t lcd_power_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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int rc;
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struct lcd_device *ld = to_lcd_device(dev);
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unsigned long power;
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rc = kstrtoul(buf, 0, &power);
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if (rc)
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return rc;
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rc = -ENXIO;
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mutex_lock(&ld->ops_lock);
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if (ld->ops && ld->ops->set_power) {
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pr_debug("set power to %lu\n", power);
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ld->ops->set_power(ld, power);
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rc = count;
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}
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mutex_unlock(&ld->ops_lock);
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return rc;
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}
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static DEVICE_ATTR_RW(lcd_power);
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static ssize_t contrast_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int rc = -ENXIO;
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struct lcd_device *ld = to_lcd_device(dev);
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mutex_lock(&ld->ops_lock);
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if (ld->ops && ld->ops->get_contrast)
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rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
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mutex_unlock(&ld->ops_lock);
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return rc;
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}
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static ssize_t contrast_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t count)
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{
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int rc;
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struct lcd_device *ld = to_lcd_device(dev);
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unsigned long contrast;
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rc = kstrtoul(buf, 0, &contrast);
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if (rc)
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return rc;
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rc = -ENXIO;
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mutex_lock(&ld->ops_lock);
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if (ld->ops && ld->ops->set_contrast) {
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pr_debug("set contrast to %lu\n", contrast);
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ld->ops->set_contrast(ld, contrast);
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rc = count;
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}
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mutex_unlock(&ld->ops_lock);
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return rc;
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}
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static DEVICE_ATTR_RW(contrast);
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static ssize_t max_contrast_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct lcd_device *ld = to_lcd_device(dev);
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return sprintf(buf, "%d\n", ld->props.max_contrast);
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}
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static DEVICE_ATTR_RO(max_contrast);
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static struct class *lcd_class;
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static void lcd_device_release(struct device *dev)
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{
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struct lcd_device *ld = to_lcd_device(dev);
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kfree(ld);
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}
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static struct attribute *lcd_device_attrs[] = {
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&dev_attr_lcd_power.attr,
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&dev_attr_contrast.attr,
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&dev_attr_max_contrast.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(lcd_device);
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/**
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* lcd_device_register - register a new object of lcd_device class.
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* @name: the name of the new object(must be the same as the name of the
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* respective framebuffer device).
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* @devdata: an optional pointer to be stored in the device. The
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* methods may retrieve it by using lcd_get_data(ld).
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* @ops: the lcd operations structure.
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*
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* Creates and registers a new lcd device. Returns either an ERR_PTR()
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* or a pointer to the newly allocated device.
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*/
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struct lcd_device *lcd_device_register(const char *name, struct device *parent,
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void *devdata, struct lcd_ops *ops)
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{
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struct lcd_device *new_ld;
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int rc;
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pr_debug("lcd_device_register: name=%s\n", name);
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new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
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if (!new_ld)
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return ERR_PTR(-ENOMEM);
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mutex_init(&new_ld->ops_lock);
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mutex_init(&new_ld->update_lock);
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new_ld->dev.class = lcd_class;
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new_ld->dev.parent = parent;
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new_ld->dev.release = lcd_device_release;
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dev_set_name(&new_ld->dev, "%s", name);
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dev_set_drvdata(&new_ld->dev, devdata);
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new_ld->ops = ops;
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rc = device_register(&new_ld->dev);
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if (rc) {
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put_device(&new_ld->dev);
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return ERR_PTR(rc);
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}
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rc = lcd_register_fb(new_ld);
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if (rc) {
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device_unregister(&new_ld->dev);
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return ERR_PTR(rc);
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}
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return new_ld;
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}
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EXPORT_SYMBOL(lcd_device_register);
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/**
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* lcd_device_unregister - unregisters a object of lcd_device class.
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* @ld: the lcd device object to be unregistered and freed.
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*
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* Unregisters a previously registered via lcd_device_register object.
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*/
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void lcd_device_unregister(struct lcd_device *ld)
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{
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if (!ld)
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return;
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mutex_lock(&ld->ops_lock);
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ld->ops = NULL;
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mutex_unlock(&ld->ops_lock);
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lcd_unregister_fb(ld);
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device_unregister(&ld->dev);
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}
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EXPORT_SYMBOL(lcd_device_unregister);
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static void devm_lcd_device_release(struct device *dev, void *res)
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{
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struct lcd_device *lcd = *(struct lcd_device **)res;
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lcd_device_unregister(lcd);
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}
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static int devm_lcd_device_match(struct device *dev, void *res, void *data)
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{
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struct lcd_device **r = res;
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return *r == data;
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}
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/**
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* devm_lcd_device_register - resource managed lcd_device_register()
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* @dev: the device to register
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* @name: the name of the device
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* @parent: a pointer to the parent device
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* @devdata: an optional pointer to be stored for private driver use
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* @ops: the lcd operations structure
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*
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* @return a struct lcd on success, or an ERR_PTR on error
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*
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* Managed lcd_device_register(). The lcd_device returned from this function
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* are automatically freed on driver detach. See lcd_device_register()
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* for more information.
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*/
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struct lcd_device *devm_lcd_device_register(struct device *dev,
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const char *name, struct device *parent,
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void *devdata, struct lcd_ops *ops)
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{
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struct lcd_device **ptr, *lcd;
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ptr = devres_alloc(devm_lcd_device_release, sizeof(*ptr), GFP_KERNEL);
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if (!ptr)
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return ERR_PTR(-ENOMEM);
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lcd = lcd_device_register(name, parent, devdata, ops);
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if (!IS_ERR(lcd)) {
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*ptr = lcd;
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devres_add(dev, ptr);
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} else {
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devres_free(ptr);
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}
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return lcd;
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}
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EXPORT_SYMBOL(devm_lcd_device_register);
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/**
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* devm_lcd_device_unregister - resource managed lcd_device_unregister()
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* @dev: the device to unregister
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* @ld: the lcd device to unregister
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*
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* Deallocated a lcd allocated with devm_lcd_device_register(). Normally
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* this function will not need to be called and the resource management
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* code will ensure that the resource is freed.
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*/
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void devm_lcd_device_unregister(struct device *dev, struct lcd_device *ld)
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{
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int rc;
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rc = devres_release(dev, devm_lcd_device_release,
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devm_lcd_device_match, ld);
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WARN_ON(rc);
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}
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EXPORT_SYMBOL(devm_lcd_device_unregister);
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static void __exit lcd_class_exit(void)
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{
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class_destroy(lcd_class);
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}
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static int __init lcd_class_init(void)
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{
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lcd_class = class_create(THIS_MODULE, "lcd");
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if (IS_ERR(lcd_class)) {
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pr_warn("Unable to create backlight class; errno = %ld\n",
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PTR_ERR(lcd_class));
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return PTR_ERR(lcd_class);
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}
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lcd_class->dev_groups = lcd_device_groups;
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return 0;
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}
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/*
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* if this is compiled into the kernel, we need to ensure that the
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* class is registered before users of the class try to register lcd's
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*/
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postcore_initcall(lcd_class_init);
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module_exit(lcd_class_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
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MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");
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