target/linux/s3c24xx/files-2.6.30/arch/arm/mach-s3c2442/gta02-pm-wlan.c

   1 /*
   2  * GTA02 WLAN power management
   3  *
   4  * (C) 2008, 2009 by Openmoko Inc.
   5  * Author: Andy Green <andy@openmoko.com>
   6  * All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation
  11  *
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/mutex.h>
  18 #include <linux/platform_device.h>
  19
  20 #include <mach/hardware.h>
  21 #include <asm/mach-types.h>
  22
  23 #include <mach/gta02.h>
  24 #include <mach/gta02-pm-wlan.h>
  25 #include <mach/regs-gpio.h>
  26 #include <mach/regs-gpioj.h>
  27
  28 #include <linux/delay.h>
  29 #include <linux/rfkill.h>
  30
  31
  32 /* ----- Module hardware reset ("power") ----------------------------------- */
  33
  34
  35 void gta02_wlan_reset(int assert_reset)
  36 {
  37         if (assert_reset) {
  38                 s3c2410_gpio_setpin(GTA02_GPIO_nWLAN_RESET, 0);
  39                 msleep(200); /* probably excessive but we don't have specs */
  40         } else {
  41                 s3c2410_gpio_setpin(GTA02_GPIO_nWLAN_RESET, 1);
  42         }
  43 }
  44
  45 /* ----- rfkill ------------------------------------------------------------ */
  46
  47 /*
  48  * S3C MCI handles suspend/resume through device removal/insertion. In order to
  49  * preserve rfkill state, as required in clause 7 of section 3.1 in rfkill.txt,
  50  * we therefore need to maintain rfkill state outside the driver.
  51  *
  52  * This platform driver is as good a place as any other.
  53  */
  54
  55 static int (*gta02_wlan_rfkill_cb)(void *user, int on);
  56 static void *gta02_wlan_rfkill_user;
  57 static DEFINE_MUTEX(gta02_wlan_rfkill_lock);
  58 static int gta02_wlan_rfkill_on;
  59
  60 /*
  61  * gta02_wlan_query_rfkill_lock is used to obtain the rfkill state before the
  62  * driver is ready to process rfkill callbacks. To prevent the state from
  63  * changing until the driver has completed its initialization, we grab and hold
  64  * the rfkill lock.
  65  *
  66  * A call to gta02_wlan_query_rfkill_lock must be followed by either
  67  * - a call to gta02_wlan_set_rfkill_cb, to complete the setup, or
  68  * - a call to gta02_wlan_query_rfkill_unlock to abort the setup process.
  69  */
  70
  71 int gta02_wlan_query_rfkill_lock(void)
  72 {
  73         mutex_lock(&gta02_wlan_rfkill_lock);
  74         return gta02_wlan_rfkill_on;
  75 }
  76 EXPORT_SYMBOL_GPL(gta02_wlan_query_rfkill_lock);
  77
  78 void gta02_wlan_query_rfkill_unlock(void)
  79 {
  80         mutex_unlock(&gta02_wlan_rfkill_lock);
  81 }
  82 EXPORT_SYMBOL_GPL(gta02_wlan_query_rfkill_unlock);
  83
  84 void gta02_wlan_set_rfkill_cb(int (*cb)(void *user, int on), void *user)
  85 {
  86         BUG_ON(!mutex_is_locked(&gta02_wlan_rfkill_lock));
  87         BUG_ON(gta02_wlan_rfkill_cb);
  88         gta02_wlan_rfkill_cb = cb;
  89         gta02_wlan_rfkill_user = user;
  90         mutex_unlock(&gta02_wlan_rfkill_lock);
  91 }
  92 EXPORT_SYMBOL_GPL(gta02_wlan_set_rfkill_cb);
  93
  94 void gta02_wlan_clear_rfkill_cb(void)
  95 {
  96         mutex_lock(&gta02_wlan_rfkill_lock);
  97         BUG_ON(!gta02_wlan_rfkill_cb);
  98         gta02_wlan_rfkill_cb = NULL;
  99         mutex_unlock(&gta02_wlan_rfkill_lock);
 100 }
 101 EXPORT_SYMBOL_GPL(gta02_wlan_clear_rfkill_cb);
 102
 103 static int gta02_wlan_toggle_radio(void *data, enum rfkill_state state)
 104 {
 105         struct device *dev = data;
 106         int on = state == RFKILL_STATE_UNBLOCKED;
 107         int res = 0;
 108
 109         dev_dbg(dev, "gta02_wlan_toggle_radio: state %d (%p)\n",
 110             state, gta02_wlan_rfkill_cb);
 111         mutex_lock(&gta02_wlan_rfkill_lock);
 112         if (gta02_wlan_rfkill_cb)
 113                 res = gta02_wlan_rfkill_cb(gta02_wlan_rfkill_user, on);
 114         if (!res)
 115                 gta02_wlan_rfkill_on = on;
 116         mutex_unlock(&gta02_wlan_rfkill_lock);
 117         return res;
 118 }
 119
 120
 121 /* ----- Initialization/removal -------------------------------------------- */
 122
 123
 124 static int __init gta02_wlan_probe(struct platform_device *pdev)
 125 {
 126         /* default-on for now */
 127         const int default_state = 1;
 128         struct rfkill *rfkill;
 129         int error;
 130
 131         dev_info(&pdev->dev, "starting\n");
 132
 133         s3c2410_gpio_cfgpin(GTA02_GPIO_nWLAN_RESET, S3C2410_GPIO_OUTPUT);
 134         gta02_wlan_reset(1);
 135         gta02_wlan_reset(0);
 136
 137         rfkill = rfkill_allocate(&pdev->dev, RFKILL_TYPE_WLAN);
 138         rfkill->name = "ar6000";
 139         rfkill->data = &pdev->dev;
 140         rfkill->state = default_state ? RFKILL_STATE_ON : RFKILL_STATE_OFF;
 141         /*
 142          * If the WLAN driver somehow managed to get activated before we're
 143          * ready, the driver is now in an unknown state, which isn't something
 144          * we're prepared to handle. This can't happen, so just fail hard.
 145          */
 146         BUG_ON(gta02_wlan_rfkill_cb);
 147         gta02_wlan_rfkill_on = default_state;
 148         rfkill->toggle_radio = gta02_wlan_toggle_radio;
 149
 150         error = rfkill_register(rfkill);
 151         if (error) {
 152                 rfkill_free(rfkill);
 153                 return error;
 154         }
 155
 156         dev_set_drvdata(&pdev->dev, rfkill);
 157
 158         return 0;
 159 }
 160
 161 static int gta02_wlan_remove(struct platform_device *pdev)
 162 {
 163         struct rfkill *rfkill = dev_get_drvdata(&pdev->dev);
 164
 165         rfkill_unregister(rfkill);
 166         rfkill_free(rfkill);
 167
 168         return 0;
 169 }
 170
 171 static struct platform_driver gta02_wlan_driver = {
 172         .probe          = gta02_wlan_probe,
 173         .remove         = gta02_wlan_remove,
 174         .driver         = {
 175                 .name           = "gta02-pm-wlan",
 176         },
 177 };
 178
 179 static int __devinit gta02_wlan_init(void)
 180 {
 181         return platform_driver_register(&gta02_wlan_driver);
 182 }
 183
 184 static void gta02_wlan_exit(void)
 185 {
 186         platform_driver_unregister(&gta02_wlan_driver);
 187 }
 188
 189 module_init(gta02_wlan_init);
 190 module_exit(gta02_wlan_exit);
 191
 192 MODULE_LICENSE("GPL");
 193 MODULE_AUTHOR("Andy Green <andy@openmoko.com>");
 194 MODULE_DESCRIPTION("Openmoko GTA02 WLAN power management");