linux/drivers/mfd/ab8500-sysctrl.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * AB8500 system control driver
   4 *
   5 * Copyright (C) ST-Ericsson SA 2010
   6 * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
   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
  27static struct device *sysctrl_dev;
  28
  29static 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
  82shutdown:
  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
  93static inline bool valid_bank(u8 bank)
  94{
  95        return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
  96                (bank == AB8500_SYS_CTRL2_BLOCK));
  97}
  98
  99int 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}
 113EXPORT_SYMBOL(ab8500_sysctrl_read);
 114
 115int 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}
 131EXPORT_SYMBOL(ab8500_sysctrl_write);
 132
 133static 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
 143static 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
 153static const struct of_device_id ab8500_sysctrl_match[] = {
 154        { .compatible = "stericsson,ab8500-sysctrl", },
 155        {}
 156};
 157
 158static 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
 167static int __init ab8500_sysctrl_init(void)
 168{
 169        return platform_driver_register(&ab8500_sysctrl_driver);
 170}
 171arch_initcall(ab8500_sysctrl_init);
 172