target/linux/s3c24xx/files-2.6.31/arch/arm/mach-s3c2442/gta02-pm-gps.c

   1 /*
   2  * GPS Power Management code for the Openmoko Freerunner GSM Phone
   3  *
   4  * (C) 2007-2009 by Openmoko Inc.
   5  * Author: Harald Welte <laforge@openmoko.org>
   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/delay.h>
  18 #include <linux/platform_device.h>
  19
  20 #include <mach/hardware.h>
  21 #include <mach/gpio-fns.h>
  22 #include <mach/cpu.h>
  23
  24 #include <asm/mach-types.h>
  25
  26 #include <mach/gta02.h>
  27 #include <linux/mfd/pcf50633/core.h>
  28 #include <linux/mfd/pcf50633/pmic.h>
  29
  30 #include <linux/regulator/consumer.h>
  31 #include <linux/err.h>
  32
  33 struct gta02_pm_gps_data {
  34 #ifdef CONFIG_PM
  35         int keep_on_in_suspend;
  36 #endif
  37         int power_was_on;
  38         struct regulator *regulator;
  39 };
  40
  41 static struct gta02_pm_gps_data gta02_gps;
  42
  43 int gta02_pm_gps_is_on(void)
  44 {
  45         return gta02_gps.power_was_on;
  46 }
  47 EXPORT_SYMBOL_GPL(gta02_pm_gps_is_on);
  48
  49 /* This is the POWERON pin */
  50 static void gps_pwron_set(int on)
  51 {
  52         if (on) {
  53                 /* return UART pins to being UART pins */
  54                 s3c2410_gpio_cfgpin(S3C2410_GPH(4), S3C2410_GPH4_TXD1);
  55                 /* remove pulldown now it won't be floating any more */
  56                 s3c2410_gpio_pullup(S3C2410_GPH(5), 0);
  57
  58                 if (!gta02_gps.power_was_on)
  59                         regulator_enable(gta02_gps.regulator);
  60         } else {
  61                 /*
  62                  * take care not to power unpowered GPS from UART TX
  63                  * return them to GPIO and force low
  64                  */
  65                 s3c2410_gpio_cfgpin(S3C2410_GPH(4), S3C2410_GPIO_OUTPUT);
  66                 s3c2410_gpio_setpin(S3C2410_GPH(4), 0);
  67                 /* don't let RX from unpowered GPS float */
  68                 s3c2410_gpio_pullup(S3C2410_GPH(5), 1);
  69                 if (gta02_gps.power_was_on)
  70                         regulator_disable(gta02_gps.regulator);
  71         }
  72 }
  73
  74 static int gps_pwron_get(void)
  75 {
  76         return regulator_is_enabled(gta02_gps.regulator);
  77 }
  78
  79 #ifdef CONFIG_PM
  80 /* This is the flag for keeping gps ON during suspend */
  81 static void gps_keep_on_in_suspend_set(int on)
  82 {
  83         gta02_gps.keep_on_in_suspend = on;
  84 }
  85
  86 static int gps_keep_on_in_suspend_get(void)
  87 {
  88         return gta02_gps.keep_on_in_suspend;
  89 }
  90 #endif
  91
  92 static ssize_t power_gps_read(struct device *dev,
  93                               struct device_attribute *attr, char *buf)
  94 {
  95         int ret = 0;
  96
  97         if (!strcmp(attr->attr.name, "power_on") ||
  98             !strcmp(attr->attr.name, "pwron")) {
  99                 ret = gps_pwron_get();
 100 #ifdef CONFIG_PM
 101         } else if (!strcmp(attr->attr.name, "keep_on_in_suspend")) {
 102                 ret = gps_keep_on_in_suspend_get();
 103 #endif
 104         }
 105         if (ret)
 106                 return strlcpy(buf, "1\n", 3);
 107         else
 108                 return strlcpy(buf, "0\n", 3);
 109 }
 110
 111 static ssize_t power_gps_write(struct device *dev,
 112                                struct device_attribute *attr, const char *buf,
 113                                size_t count)
 114 {
 115         unsigned long on = simple_strtoul(buf, NULL, 10);
 116
 117         if (!strcmp(attr->attr.name, "power_on") ||
 118             !strcmp(attr->attr.name, "pwron")) {
 119                 gps_pwron_set(on);
 120                 gta02_gps.power_was_on = !!on;
 121 #ifdef CONFIG_PM
 122         } else if (!strcmp(attr->attr.name, "keep_on_in_suspend")) {
 123                 gps_keep_on_in_suspend_set(on);
 124 #endif
 125         }
 126         return count;
 127 }
 128
 129 #ifdef CONFIG_PM
 130 static int gta02_pm_gps_suspend(struct platform_device *pdev,
 131                                 pm_message_t state)
 132 {
 133         if (!gta02_gps.keep_on_in_suspend ||
 134                 !gta02_gps.power_was_on)
 135                 gps_pwron_set(0);
 136         else
 137                 dev_warn(&pdev->dev, "GTA02: keeping gps ON "
 138                          "during suspend\n");
 139         return 0;
 140 }
 141
 142 static int gta02_pm_gps_resume(struct platform_device *pdev)
 143 {
 144         if (!gta02_gps.keep_on_in_suspend && gta02_gps.power_was_on)
 145                 gps_pwron_set(1);
 146
 147         return 0;
 148 }
 149
 150 static DEVICE_ATTR(keep_on_in_suspend, 0644, power_gps_read, power_gps_write);
 151 #else
 152 #define gta02_pm_gps_suspend    NULL
 153 #define gta02_pm_gps_resume     NULL
 154 #endif
 155
 156 static DEVICE_ATTR(power_on, 0644, power_gps_read, power_gps_write);
 157
 158 static struct attribute *gta02_gps_sysfs_entries[] = {
 159         &dev_attr_power_on.attr,
 160 #ifdef CONFIG_PM
 161         &dev_attr_keep_on_in_suspend.attr,
 162 #endif
 163         NULL
 164 };
 165
 166 static struct attribute_group gta02_gps_attr_group = {
 167         .name   = NULL,
 168         .attrs  = gta02_gps_sysfs_entries,
 169 };
 170
 171 static int __init gta02_pm_gps_probe(struct platform_device *pdev)
 172 {
 173         gta02_gps.regulator = regulator_get(&pdev->dev, "RF_3V");
 174         if (IS_ERR(gta02_gps.regulator)) {
 175                 dev_err(&pdev->dev, "probe failed %ld\n",
 176                         PTR_ERR(gta02_gps.regulator));
 177
 178                 return PTR_ERR(gta02_gps.regulator);
 179         }
 180
 181         dev_info(&pdev->dev, "starting\n");
 182
 183         /*
 184          * Here we should call the code that handles the set GPS power
 185          * off action.  But, the regulator API does not allow us to
 186          * reassert regulator state, and when we read the regulator API
 187          * logical state, it can differ from the actual state,  So
 188          * a workaround for this is to just set the regulator off in the
 189          * PMU directly.  Because that's different from normal flow, we
 190          * have to reproduce other things from the OFF action here too.
 191          */
 192
 193         /*
 194          * u-boot enables LDO5 (GPS), which doesn't make sense and
 195          * causes confusion. We therefore disable the regulator here.
 196          */
 197         pcf50633_reg_write(gta02_pcf, PCF50633_REG_LDO5ENA, 0);
 198
 199         /*
 200          * take care not to power unpowered GPS from UART TX
 201          * return them to GPIO and force low
 202          */
 203         s3c2410_gpio_cfgpin(S3C2410_GPH(4), S3C2410_GPIO_OUTPUT);
 204         s3c2410_gpio_setpin(S3C2410_GPH(4), 0);
 205         /* don't let RX from unpowered GPS float */
 206         s3c2410_gpio_pullup(S3C2410_GPH(5), 1);
 207
 208         return sysfs_create_group(&pdev->dev.kobj,
 209                                   &gta02_gps_attr_group);
 210 }
 211
 212 static int gta02_pm_gps_remove(struct platform_device *pdev)
 213 {
 214         regulator_put(gta02_gps.regulator);
 215         sysfs_remove_group(&pdev->dev.kobj, &gta02_gps_attr_group);
 216         return 0;
 217 }
 218
 219 static struct platform_driver gta02_pm_gps_driver = {
 220         .probe          = gta02_pm_gps_probe,
 221         .remove         = gta02_pm_gps_remove,
 222         .suspend        = gta02_pm_gps_suspend,
 223         .resume         = gta02_pm_gps_resume,
 224         .driver         = {
 225                 .name           = "gta02-pm-gps",
 226         },
 227 };
 228
 229 static int __devinit gta02_pm_gps_init(void)
 230 {
 231         return platform_driver_register(&gta02_pm_gps_driver);
 232 }
 233
 234 static void gta02_pm_gps_exit(void)
 235 {
 236         platform_driver_unregister(&gta02_pm_gps_driver);
 237 }
 238
 239 module_init(gta02_pm_gps_init);
 240 module_exit(gta02_pm_gps_exit);
 241
 242 MODULE_LICENSE("GPL");
 243 MODULE_AUTHOR("Harald Welte <laforge@openmoko.org>");