target/linux/goldfish/patches-2.6.30/0072-PM-earlysuspend-Removing-dependence-on-console.patch

   1 From ba801aa66e869f1f9f9d3a1610a2165baa024e4b Mon Sep 17 00:00:00 2001
   2 From: Rebecca Schultz <rschultz@google.com>
   3 Date: Thu, 17 Jul 2008 18:14:55 -0700
   4 Subject: [PATCH 072/134] PM: earlysuspend: Removing dependence on console.
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=utf-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Rather than signaling a full update of the display from userspace via a
  10 console switch, this patch introduces 2 files int /sys/power,
  11 wait_for_fb_sleep and wait_for_fb_wake.  Reading these files will block
  12 until the requested state has been entered.  When a read from
  13 wait_for_fb_sleep returns userspace should stop drawing.  When
  14 wait_for_fb_wake returns, it should do a full update.  If either are called
  15 when the fb driver is already in the requested state, they will return
  16 immediately.
  17
  18 Signed-off-by: Rebecca Schultz <rschultz@google.com>
  19 Signed-off-by: Arve Hjønnevåg <arve@android.com>
  20 ---
  21  kernel/power/Kconfig          |    9 +++
  22  kernel/power/Makefile         |    1 +
  23  kernel/power/fbearlysuspend.c |  153 +++++++++++++++++++++++++++++++++++++++++
  24  3 files changed, 163 insertions(+), 0 deletions(-)
  25  create mode 100644 kernel/power/fbearlysuspend.c
  26
  27 --- a/kernel/power/Kconfig
  28 +++ b/kernel/power/Kconfig
  29 @@ -159,6 +159,7 @@ config EARLYSUSPEND
  30
  31  choice
  32         prompt "User-space screen access"
  33 +       default FB_EARLYSUSPEND if !FRAMEBUFFER_CONSOLE
  34         default CONSOLE_EARLYSUSPEND
  35         depends on HAS_EARLYSUSPEND
  36
  37 @@ -172,6 +173,14 @@ choice
  38                   Register early suspend handler to perform a console switch to
  39                   when user-space should stop drawing to the screen and a switch
  40                   back when it should resume.
  41 +
  42 +       config FB_EARLYSUSPEND
  43 +               bool "Sysfs interface"
  44 +               depends on HAS_EARLYSUSPEND
  45 +               ---help---
  46 +                 Register early suspend handler that notifies and waits for
  47 +                 user-space through sysfs when user-space should stop drawing
  48 +                 to the screen and notifies user-space when it should resume.
  49  endchoice
  50
  51  config HIBERNATION
  52 --- a/kernel/power/Makefile
  53 +++ b/kernel/power/Makefile
  54 @@ -10,6 +10,7 @@ obj-$(CONFIG_WAKELOCK)                += wakelock.o
  55  obj-$(CONFIG_USER_WAKELOCK)    += userwakelock.o
  56  obj-$(CONFIG_EARLYSUSPEND)     += earlysuspend.o
  57  obj-$(CONFIG_CONSOLE_EARLYSUSPEND)     += consoleearlysuspend.o
  58 +obj-$(CONFIG_FB_EARLYSUSPEND)  += fbearlysuspend.o
  59  obj-$(CONFIG_HIBERNATION)      += swsusp.o disk.o snapshot.o swap.o user.o
  60
  61  obj-$(CONFIG_MAGIC_SYSRQ)      += poweroff.o
  62 --- /dev/null
  63 +++ b/kernel/power/fbearlysuspend.c
  64 @@ -0,0 +1,153 @@
  65 +/* kernel/power/fbearlysuspend.c
  66 + *
  67 + * Copyright (C) 2005-2008 Google, Inc.
  68 + *
  69 + * This software is licensed under the terms of the GNU General Public
  70 + * License version 2, as published by the Free Software Foundation, and
  71 + * may be copied, distributed, and modified under those terms.
  72 + *
  73 + * This program is distributed in the hope that it will be useful,
  74 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  75 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  76 + * GNU General Public License for more details.
  77 + *
  78 + */
  79 +
  80 +#include <linux/earlysuspend.h>
  81 +#include <linux/module.h>
  82 +#include <linux/wait.h>
  83 +
  84 +#include "power.h"
  85 +
  86 +static wait_queue_head_t fb_state_wq;
  87 +static DEFINE_SPINLOCK(fb_state_lock);
  88 +static enum {
  89 +       FB_STATE_STOPPED_DRAWING,
  90 +       FB_STATE_REQUEST_STOP_DRAWING,
  91 +       FB_STATE_DRAWING_OK,
  92 +} fb_state;
  93 +
  94 +/* tell userspace to stop drawing, wait for it to stop */
  95 +static void stop_drawing_early_suspend(struct early_suspend *h)
  96 +{
  97 +       int ret;
  98 +       unsigned long irq_flags;
  99 +
 100 +       spin_lock_irqsave(&fb_state_lock, irq_flags);
 101 +       fb_state = FB_STATE_REQUEST_STOP_DRAWING;
 102 +       spin_unlock_irqrestore(&fb_state_lock, irq_flags);
 103 +
 104 +       wake_up_all(&fb_state_wq);
 105 +       ret = wait_event_timeout(fb_state_wq,
 106 +                                fb_state == FB_STATE_STOPPED_DRAWING,
 107 +                                HZ);
 108 +       if (unlikely(fb_state != FB_STATE_STOPPED_DRAWING))
 109 +               pr_warning("stop_drawing_early_suspend: timeout waiting for "
 110 +                          "userspace to stop drawing\n");
 111 +}
 112 +
 113 +/* tell userspace to start drawing */
 114 +static void start_drawing_late_resume(struct early_suspend *h)
 115 +{
 116 +       unsigned long irq_flags;
 117 +
 118 +       spin_lock_irqsave(&fb_state_lock, irq_flags);
 119 +       fb_state = FB_STATE_DRAWING_OK;
 120 +       spin_unlock_irqrestore(&fb_state_lock, irq_flags);
 121 +       wake_up(&fb_state_wq);
 122 +}
 123 +
 124 +static struct early_suspend stop_drawing_early_suspend_desc = {
 125 +       .level = EARLY_SUSPEND_LEVEL_STOP_DRAWING,
 126 +       .suspend = stop_drawing_early_suspend,
 127 +       .resume = start_drawing_late_resume,
 128 +};
 129 +
 130 +static ssize_t wait_for_fb_sleep_show(struct kobject *kobj,
 131 +                                     struct kobj_attribute *attr, char *buf)
 132 +{
 133 +       char *s = buf;
 134 +       int ret;
 135 +
 136 +       ret = wait_event_interruptible(fb_state_wq,
 137 +                                      fb_state != FB_STATE_DRAWING_OK);
 138 +       if (ret && fb_state == FB_STATE_DRAWING_OK)
 139 +               return ret;
 140 +       else
 141 +               s += sprintf(buf, "sleeping");
 142 +       return s - buf;
 143 +}
 144 +
 145 +static ssize_t wait_for_fb_wake_show(struct kobject *kobj,
 146 +                                    struct kobj_attribute *attr, char *buf)
 147 +{
 148 +       char *s = buf;
 149 +       int ret;
 150 +       unsigned long irq_flags;
 151 +
 152 +       spin_lock_irqsave(&fb_state_lock, irq_flags);
 153 +       if (fb_state == FB_STATE_REQUEST_STOP_DRAWING) {
 154 +               fb_state = FB_STATE_STOPPED_DRAWING;
 155 +               wake_up(&fb_state_wq);
 156 +       }
 157 +       spin_unlock_irqrestore(&fb_state_lock, irq_flags);
 158 +
 159 +       ret = wait_event_interruptible(fb_state_wq,
 160 +                                      fb_state == FB_STATE_DRAWING_OK);
 161 +       if (ret && fb_state != FB_STATE_DRAWING_OK)
 162 +               return ret;
 163 +       else
 164 +               s += sprintf(buf, "awake");
 165 +
 166 +       return s - buf;
 167 +}
 168 +
 169 +#define power_ro_attr(_name) \
 170 +static struct kobj_attribute _name##_attr = {  \
 171 +       .attr   = {                             \
 172 +               .name = __stringify(_name),     \
 173 +               .mode = 0444,                   \
 174 +       },                                      \
 175 +       .show   = _name##_show,                 \
 176 +       .store  = NULL,         \
 177 +}
 178 +
 179 +power_ro_attr(wait_for_fb_sleep);
 180 +power_ro_attr(wait_for_fb_wake);
 181 +
 182 +static struct attribute *g[] = {
 183 +       &wait_for_fb_sleep_attr.attr,
 184 +       &wait_for_fb_wake_attr.attr,
 185 +       NULL,
 186 +};
 187 +
 188 +static struct attribute_group attr_group = {
 189 +       .attrs = g,
 190 +};
 191 +
 192 +static int __init android_power_init(void)
 193 +{
 194 +       int ret;
 195 +
 196 +       init_waitqueue_head(&fb_state_wq);
 197 +       fb_state = FB_STATE_DRAWING_OK;
 198 +
 199 +       ret = sysfs_create_group(power_kobj, &attr_group);
 200 +       if (ret) {
 201 +               pr_err("android_power_init: sysfs_create_group failed\n");
 202 +               return ret;
 203 +       }
 204 +
 205 +       register_early_suspend(&stop_drawing_early_suspend_desc);
 206 +       return 0;
 207 +}
 208 +
 209 +static void  __exit android_power_exit(void)
 210 +{
 211 +       unregister_early_suspend(&stop_drawing_early_suspend_desc);
 212 +       sysfs_remove_group(power_kobj, &attr_group);
 213 +}
 214 +
 215 +module_init(android_power_init);
 216 +module_exit(android_power_exit);
 217 +