drivers/mfd/ab8500-sysctrl.c

   1 /*
   2  * AB8500 system control driver
   3  *
   4  * Copyright (C) ST-Ericsson SA 2010
   5  * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
   6  * License terms: GNU General Public License (GPL) version 2
   7  */
   8
   9 #include <linux/err.h>
  10 #include <linux/init.h>
  11 #include <linux/export.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/pm.h>
  14 #include <linux/reboot.h>
  15 #include <linux/signal.h>
  16 #include <linux/power_supply.h>
  17 #include <linux/mfd/abx500.h>
  18 #include <linux/mfd/abx500/ab8500.h>
  19 #include <linux/mfd/abx500/ab8500-sysctrl.h>
  20
  21 /* RtcCtrl bits */
  22 #define AB8500_ALARM_MIN_LOW  0x08
  23 #define AB8500_ALARM_MIN_MID 0x09
  24 #define RTC_CTRL 0x0B
  25 #define RTC_ALARM_ENABLE 0x4
  26
  27 static struct device *sysctrl_dev;
  28
  29 static void ab8500_power_off(void)
  30 {
  31         sigset_t old;
  32         sigset_t all;
  33         static const char * const pss[] = {"ab8500_ac", "pm2301", "ab8500_usb"};
  34         int i;
  35         bool charger_present = false;
  36         union power_supply_propval val;
  37         struct power_supply *psy;
  38         int ret;
  39
  40         if (sysctrl_dev == NULL) {
  41                 pr_err("%s: sysctrl not initialized\n", __func__);
  42                 return;
  43         }
  44
  45         /*
  46          * If we have a charger connected and we're powering off,
  47          * reboot into charge-only mode.
  48          */
  49
  50         for (i = 0; i < ARRAY_SIZE(pss); i++) {
  51                 psy = power_supply_get_by_name(pss[i]);
  52                 if (!psy)
  53                         continue;
  54
  55                 ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
  56                                 &val);
  57                 power_supply_put(psy);
  58
  59                 if (!ret && val.intval) {
  60                         charger_present = true;
  61                         break;
  62                 }
  63         }
  64
  65         if (!charger_present)
  66                 goto shutdown;
  67
  68         /* Check if battery is known */
  69         psy = power_supply_get_by_name("ab8500_btemp");
  70         if (psy) {
  71                 ret = power_supply_get_property(psy,
  72                                 POWER_SUPPLY_PROP_TECHNOLOGY, &val);
  73                 if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
  74                         pr_info("Charger '%s' is connected with known battery",
  75                                 pss[i]);
  76                         pr_info(" - Rebooting.\n");
  77                         machine_restart("charging");
  78                 }
  79                 power_supply_put(psy);
  80         }
  81
  82 shutdown:
  83         sigfillset(&all);
  84
  85         if (!sigprocmask(SIG_BLOCK, &all, &old)) {
  86                 (void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
  87                                          AB8500_STW4500CTRL1_SWOFF |
  88                                          AB8500_STW4500CTRL1_SWRESET4500N);
  89                 (void)sigprocmask(SIG_SETMASK, &old, NULL);
  90         }
  91 }
  92
  93 static inline bool valid_bank(u8 bank)
  94 {
  95         return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
  96                 (bank == AB8500_SYS_CTRL2_BLOCK));
  97 }
  98
  99 int ab8500_sysctrl_read(u16 reg, u8 *value)
 100 {
 101         u8 bank;
 102
 103         if (sysctrl_dev == NULL)
 104                 return -EPROBE_DEFER;
 105
 106         bank = (reg >> 8);
 107         if (!valid_bank(bank))
 108                 return -EINVAL;
 109
 110         return abx500_get_register_interruptible(sysctrl_dev, bank,
 111                 (u8)(reg & 0xFF), value);
 112 }
 113 EXPORT_SYMBOL(ab8500_sysctrl_read);
 114
 115 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
 116 {
 117         u8 bank;
 118
 119         if (sysctrl_dev == NULL)
 120                 return -EPROBE_DEFER;
 121
 122         bank = (reg >> 8);
 123         if (!valid_bank(bank)) {
 124                 pr_err("invalid bank\n");
 125                 return -EINVAL;
 126         }
 127
 128         return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
 129                 (u8)(reg & 0xFF), mask, value);
 130 }
 131 EXPORT_SYMBOL(ab8500_sysctrl_write);
 132
 133 static int ab8500_sysctrl_probe(struct platform_device *pdev)
 134 {
 135         sysctrl_dev = &pdev->dev;
 136
 137         if (!pm_power_off)
 138                 pm_power_off = ab8500_power_off;
 139
 140         return 0;
 141 }
 142
 143 static int ab8500_sysctrl_remove(struct platform_device *pdev)
 144 {
 145         sysctrl_dev = NULL;
 146
 147         if (pm_power_off == ab8500_power_off)
 148                 pm_power_off = NULL;
 149
 150         return 0;
 151 }
 152
 153 static const struct of_device_id ab8500_sysctrl_match[] = {
 154         { .compatible = "stericsson,ab8500-sysctrl", },
 155         {}
 156 };
 157
 158 static struct platform_driver ab8500_sysctrl_driver = {
 159         .driver = {
 160                 .name = "ab8500-sysctrl",
 161                 .of_match_table = ab8500_sysctrl_match,
 162         },
 163         .probe = ab8500_sysctrl_probe,
 164         .remove = ab8500_sysctrl_remove,
 165 };
 166
 167 static int __init ab8500_sysctrl_init(void)
 168 {
 169         return platform_driver_register(&ab8500_sysctrl_driver);
 170 }
 171 arch_initcall(ab8500_sysctrl_init);