![Stephen Rothwell](/assets/img/avatar_default.png)
Replace uses with of_find_node_by_name and for_each_node_by_name. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
220 lines
5.4 KiB
C
220 lines
5.4 KiB
C
/*
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* Miscellaneous procedures for dealing with the PowerMac hardware.
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* Contains support for the backlight.
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*
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* Copyright (C) 2000 Benjamin Herrenschmidt
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* Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
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*
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*/
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#include <linux/kernel.h>
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#include <linux/fb.h>
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#include <linux/backlight.h>
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#include <linux/adb.h>
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#include <linux/pmu.h>
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#include <asm/atomic.h>
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#include <asm/prom.h>
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#include <asm/backlight.h>
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#define OLD_BACKLIGHT_MAX 15
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static void pmac_backlight_key_worker(struct work_struct *work);
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static void pmac_backlight_set_legacy_worker(struct work_struct *work);
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static DECLARE_WORK(pmac_backlight_key_work, pmac_backlight_key_worker);
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static DECLARE_WORK(pmac_backlight_set_legacy_work, pmac_backlight_set_legacy_worker);
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/* Although these variables are used in interrupt context, it makes no sense to
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* protect them. No user is able to produce enough key events per second and
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* notice the errors that might happen.
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*/
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static int pmac_backlight_key_queued;
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static int pmac_backlight_set_legacy_queued;
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/* The via-pmu code allows the backlight to be grabbed, in which case the
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* in-kernel control of the brightness needs to be disabled. This should
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* only be used by really old PowerBooks.
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*/
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static atomic_t kernel_backlight_disabled = ATOMIC_INIT(0);
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/* Protect the pmac_backlight variable below.
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You should hold this lock when using the pmac_backlight pointer to
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prevent its potential removal. */
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DEFINE_MUTEX(pmac_backlight_mutex);
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/* Main backlight storage
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*
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* Backlight drivers in this variable are required to have the "ops"
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* attribute set and to have an update_status function.
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*
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* We can only store one backlight here, but since Apple laptops have only one
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* internal display, it doesn't matter. Other backlight drivers can be used
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* independently.
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*
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*/
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struct backlight_device *pmac_backlight;
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int pmac_has_backlight_type(const char *type)
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{
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struct device_node* bk_node = of_find_node_by_name(NULL, "backlight");
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if (bk_node) {
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const char *prop = of_get_property(bk_node,
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"backlight-control", NULL);
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if (prop && strncmp(prop, type, strlen(type)) == 0) {
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of_node_put(bk_node);
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return 1;
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}
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of_node_put(bk_node);
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}
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return 0;
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}
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int pmac_backlight_curve_lookup(struct fb_info *info, int value)
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{
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int level = (FB_BACKLIGHT_LEVELS - 1);
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if (info && info->bl_dev) {
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int i, max = 0;
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/* Look for biggest value */
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for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
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max = max((int)info->bl_curve[i], max);
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/* Look for nearest value */
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for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
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int diff = abs(info->bl_curve[i] - value);
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if (diff < max) {
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max = diff;
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level = i;
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}
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}
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}
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return level;
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}
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static void pmac_backlight_key_worker(struct work_struct *work)
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{
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if (atomic_read(&kernel_backlight_disabled))
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return;
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mutex_lock(&pmac_backlight_mutex);
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if (pmac_backlight) {
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struct backlight_properties *props;
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int brightness;
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props = &pmac_backlight->props;
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brightness = props->brightness +
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((pmac_backlight_key_queued?-1:1) *
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(props->max_brightness / 15));
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if (brightness < 0)
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brightness = 0;
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else if (brightness > props->max_brightness)
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brightness = props->max_brightness;
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props->brightness = brightness;
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backlight_update_status(pmac_backlight);
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}
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mutex_unlock(&pmac_backlight_mutex);
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}
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/* This function is called in interrupt context */
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void pmac_backlight_key(int direction)
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{
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if (atomic_read(&kernel_backlight_disabled))
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return;
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/* we can receive multiple interrupts here, but the scheduled work
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* will run only once, with the last value
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*/
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pmac_backlight_key_queued = direction;
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schedule_work(&pmac_backlight_key_work);
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}
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static int __pmac_backlight_set_legacy_brightness(int brightness)
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{
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int error = -ENXIO;
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mutex_lock(&pmac_backlight_mutex);
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if (pmac_backlight) {
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struct backlight_properties *props;
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props = &pmac_backlight->props;
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props->brightness = brightness *
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(props->max_brightness + 1) /
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(OLD_BACKLIGHT_MAX + 1);
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if (props->brightness > props->max_brightness)
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props->brightness = props->max_brightness;
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else if (props->brightness < 0)
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props->brightness = 0;
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backlight_update_status(pmac_backlight);
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error = 0;
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}
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mutex_unlock(&pmac_backlight_mutex);
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return error;
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}
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static void pmac_backlight_set_legacy_worker(struct work_struct *work)
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{
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if (atomic_read(&kernel_backlight_disabled))
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return;
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__pmac_backlight_set_legacy_brightness(pmac_backlight_set_legacy_queued);
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}
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/* This function is called in interrupt context */
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void pmac_backlight_set_legacy_brightness_pmu(int brightness) {
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if (atomic_read(&kernel_backlight_disabled))
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return;
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pmac_backlight_set_legacy_queued = brightness;
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schedule_work(&pmac_backlight_set_legacy_work);
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}
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int pmac_backlight_set_legacy_brightness(int brightness)
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{
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return __pmac_backlight_set_legacy_brightness(brightness);
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}
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int pmac_backlight_get_legacy_brightness()
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{
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int result = -ENXIO;
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mutex_lock(&pmac_backlight_mutex);
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if (pmac_backlight) {
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struct backlight_properties *props;
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props = &pmac_backlight->props;
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result = props->brightness *
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(OLD_BACKLIGHT_MAX + 1) /
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(props->max_brightness + 1);
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}
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mutex_unlock(&pmac_backlight_mutex);
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return result;
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}
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void pmac_backlight_disable()
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{
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atomic_inc(&kernel_backlight_disabled);
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}
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void pmac_backlight_enable()
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{
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atomic_dec(&kernel_backlight_disabled);
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}
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EXPORT_SYMBOL_GPL(pmac_backlight);
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EXPORT_SYMBOL_GPL(pmac_backlight_mutex);
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EXPORT_SYMBOL_GPL(pmac_has_backlight_type);
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