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