drivers/mfd/ab8500-sysctrl.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010
   3  * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
   4  * License terms: GNU General Public License (GPL) version 2
   5  */
   6
   7 #include <linux/err.h>
   8 #include <linux/module.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/pm.h>
  11 #include <linux/reboot.h>
  12 #include <linux/signal.h>
  13 #include <linux/power_supply.h>
  14 #include <linux/mfd/abx500.h>
  15 #include <linux/mfd/abx500/ab8500.h>
  16 #include <linux/mfd/abx500/ab8500-sysctrl.h>
  17
  18 /* RtcCtrl bits */
  19 #define AB8500_ALARM_MIN_LOW  0x08
  20 #define AB8500_ALARM_MIN_MID 0x09
  21 #define RTC_CTRL 0x0B
  22 #define RTC_ALARM_ENABLE 0x4
  23
  24 static struct device *sysctrl_dev;
  25
  26 static void ab8500_power_off(void)
  27 {
  28         sigset_t old;
  29         sigset_t all;
  30         static const char * const pss[] = {"ab8500_ac", "pm2301", "ab8500_usb"};
  31         int i;
  32         bool charger_present = false;
  33         union power_supply_propval val;
  34         struct power_supply *psy;
  35         int ret;
  36
  37         if (sysctrl_dev == NULL) {
  38                 pr_err("%s: sysctrl not initialized\n", __func__);
  39                 return;
  40         }
  41
  42         /*
  43          * If we have a charger connected and we're powering off,
  44          * reboot into charge-only mode.
  45          */
  46
  47         for (i = 0; i < ARRAY_SIZE(pss); i++) {
  48                 psy = power_supply_get_by_name(pss[i]);
  49                 if (!psy)
  50                         continue;
  51
  52                 ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
  53                                 &val);
  54                 power_supply_put(psy);
  55
  56                 if (!ret && val.intval) {
  57                         charger_present = true;
  58                         break;
  59                 }
  60         }
  61
  62         if (!charger_present)
  63                 goto shutdown;
  64
  65         /* Check if battery is known */
  66         psy = power_supply_get_by_name("ab8500_btemp");
  67         if (psy) {
  68                 ret = power_supply_get_property(psy,
  69                                 POWER_SUPPLY_PROP_TECHNOLOGY, &val);
  70                 if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
  71                         pr_info("Charger '%s' is connected with known battery",
  72                                 pss[i]);
  73                         pr_info(" - Rebooting.\n");
  74                         machine_restart("charging");
  75                 }
  76                 power_supply_put(psy);
  77         }
  78
  79 shutdown:
  80         sigfillset(&all);
  81
  82         if (!sigprocmask(SIG_BLOCK, &all, &old)) {
  83                 (void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
  84                                          AB8500_STW4500CTRL1_SWOFF |
  85                                          AB8500_STW4500CTRL1_SWRESET4500N);
  86                 (void)sigprocmask(SIG_SETMASK, &old, NULL);
  87         }
  88 }
  89
  90 static inline bool valid_bank(u8 bank)
  91 {
  92         return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
  93                 (bank == AB8500_SYS_CTRL2_BLOCK));
  94 }
  95
  96 int ab8500_sysctrl_read(u16 reg, u8 *value)
  97 {
  98         u8 bank;
  99
 100         if (sysctrl_dev == NULL)
 101                 return -EINVAL;
 102
 103         bank = (reg >> 8);
 104         if (!valid_bank(bank))
 105                 return -EINVAL;
 106
 107         return abx500_get_register_interruptible(sysctrl_dev, bank,
 108                 (u8)(reg & 0xFF), value);
 109 }
 110 EXPORT_SYMBOL(ab8500_sysctrl_read);
 111
 112 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
 113 {
 114         u8 bank;
 115
 116         if (sysctrl_dev == NULL)
 117                 return -EINVAL;
 118
 119         bank = (reg >> 8);
 120         if (!valid_bank(bank))
 121                 return -EINVAL;
 122
 123         return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
 124                 (u8)(reg & 0xFF), mask, value);
 125 }
 126 EXPORT_SYMBOL(ab8500_sysctrl_write);
 127
 128 static int ab8500_sysctrl_probe(struct platform_device *pdev)
 129 {
 130         sysctrl_dev = &pdev->dev;
 131
 132         if (!pm_power_off)
 133                 pm_power_off = ab8500_power_off;
 134
 135         return 0;
 136 }
 137
 138 static int ab8500_sysctrl_remove(struct platform_device *pdev)
 139 {
 140         sysctrl_dev = NULL;
 141
 142         if (pm_power_off == ab8500_power_off)
 143                 pm_power_off = NULL;
 144
 145         return 0;
 146 }
 147
 148 static struct platform_driver ab8500_sysctrl_driver = {
 149         .driver = {
 150                 .name = "ab8500-sysctrl",
 151         },
 152         .probe = ab8500_sysctrl_probe,
 153         .remove = ab8500_sysctrl_remove,
 154 };
 155
 156 static int __init ab8500_sysctrl_init(void)
 157 {
 158         return platform_driver_register(&ab8500_sysctrl_driver);
 159 }
 160 arch_initcall(ab8500_sysctrl_init);
 161
 162 MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
 163 MODULE_DESCRIPTION("AB8500 system control driver");
 164 MODULE_LICENSE("GPL v2");