linux/drivers/mfd/ab8500-sysctrl.c
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   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
  24static struct device *sysctrl_dev;
  25
  26static void ab8500_power_off(void)
  27{
  28        sigset_t old;
  29        sigset_t all;
  30        static char *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 = psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &val);
  53
  54                if (!ret && val.intval) {
  55                        charger_present = true;
  56                        break;
  57                }
  58        }
  59
  60        if (!charger_present)
  61                goto shutdown;
  62
  63        /* Check if battery is known */
  64        psy = power_supply_get_by_name("ab8500_btemp");
  65        if (psy) {
  66                ret = psy->get_property(psy, POWER_SUPPLY_PROP_TECHNOLOGY,
  67                                        &val);
  68                if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
  69                        printk(KERN_INFO
  70                               "Charger \"%s\" is connected with known battery."
  71                               " Rebooting.\n",
  72                               pss[i]);
  73                        machine_restart("charging");
  74                }
  75        }
  76
  77shutdown:
  78        sigfillset(&all);
  79
  80        if (!sigprocmask(SIG_BLOCK, &all, &old)) {
  81                (void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
  82                                         AB8500_STW4500CTRL1_SWOFF |
  83                                         AB8500_STW4500CTRL1_SWRESET4500N);
  84                (void)sigprocmask(SIG_SETMASK, &old, NULL);
  85        }
  86}
  87
  88/*
  89 * Use the AB WD to reset the platform. It will perform a hard
  90 * reset instead of a soft reset. Write the reset reason to
  91 * the AB before reset, which can be read upon restart.
  92 */
  93void ab8500_restart(char mode, const char *cmd)
  94{
  95        struct ab8500_platform_data *plat;
  96        struct ab8500_sysctrl_platform_data *pdata;
  97        u16 reason = 0;
  98        u8 val;
  99
 100        if (sysctrl_dev == NULL) {
 101                pr_err("%s: sysctrl not initialized\n", __func__);
 102                return;
 103        }
 104
 105        plat = dev_get_platdata(sysctrl_dev->parent);
 106        pdata = plat->sysctrl;
 107        if (pdata && pdata->reboot_reason_code)
 108                reason = pdata->reboot_reason_code(cmd);
 109        else
 110                pr_warn("[%s] No reboot reason set. Default reason %d\n",
 111                        __func__, reason);
 112
 113        /*
 114         * Disable RTC alarm, just a precaution so that no alarm
 115         * is running when WD reset is executed.
 116         */
 117        abx500_get_register_interruptible(sysctrl_dev, AB8500_RTC,
 118                RTC_CTRL , &val);
 119        abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
 120                RTC_CTRL , (val & ~RTC_ALARM_ENABLE));
 121
 122        /*
 123         * Android is not using the RTC alarm registers during reboot
 124         * so we borrow them for writing the reason of reset
 125         */
 126
 127        /* reason[8 LSB] */
 128        val = reason & 0xFF;
 129        abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
 130                AB8500_ALARM_MIN_LOW , val);
 131
 132        /* reason[8 MSB] */
 133        val = (reason>>8) & 0xFF;
 134        abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
 135                AB8500_ALARM_MIN_MID , val);
 136
 137        /* Setting WD timeout to 0 */
 138        ab8500_sysctrl_write(AB8500_MAINWDOGTIMER, 0xFF, 0x0);
 139
 140        /* Setting the parameters to AB8500 WD*/
 141        ab8500_sysctrl_write(AB8500_MAINWDOGCTRL, 0xFF, (AB8500_ENABLE_WD |
 142                AB8500_WD_RESTART_ON_EXPIRE | AB8500_KICK_WD));
 143}
 144
 145static inline bool valid_bank(u8 bank)
 146{
 147        return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
 148                (bank == AB8500_SYS_CTRL2_BLOCK));
 149}
 150
 151int ab8500_sysctrl_read(u16 reg, u8 *value)
 152{
 153        u8 bank;
 154
 155        if (sysctrl_dev == NULL)
 156                return -EINVAL;
 157
 158        bank = (reg >> 8);
 159        if (!valid_bank(bank))
 160                return -EINVAL;
 161
 162        return abx500_get_register_interruptible(sysctrl_dev, bank,
 163                (u8)(reg & 0xFF), value);
 164}
 165EXPORT_SYMBOL(ab8500_sysctrl_read);
 166
 167int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
 168{
 169        u8 bank;
 170
 171        if (sysctrl_dev == NULL)
 172                return -EINVAL;
 173
 174        bank = (reg >> 8);
 175        if (!valid_bank(bank))
 176                return -EINVAL;
 177
 178        return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
 179                (u8)(reg & 0xFF), mask, value);
 180}
 181EXPORT_SYMBOL(ab8500_sysctrl_write);
 182
 183static int ab8500_sysctrl_probe(struct platform_device *pdev)
 184{
 185        struct ab8500 *ab8500 = dev_get_drvdata(pdev->dev.parent);
 186        struct ab8500_platform_data *plat;
 187        struct ab8500_sysctrl_platform_data *pdata;
 188
 189        plat = dev_get_platdata(pdev->dev.parent);
 190
 191        if (!plat)
 192                return -EINVAL;
 193
 194        sysctrl_dev = &pdev->dev;
 195
 196        if (!pm_power_off)
 197                pm_power_off = ab8500_power_off;
 198
 199        pdata = plat->sysctrl;
 200        if (pdata) {
 201                int last, ret, i, j;
 202
 203                if (is_ab8505(ab8500))
 204                        last = AB8500_SYSCLKREQ4RFCLKBUF;
 205                else
 206                        last = AB8500_SYSCLKREQ8RFCLKBUF;
 207
 208                for (i = AB8500_SYSCLKREQ1RFCLKBUF; i <= last; i++) {
 209                        j = i - AB8500_SYSCLKREQ1RFCLKBUF;
 210                        ret = ab8500_sysctrl_write(i, 0xff,
 211                                        pdata->initial_req_buf_config[j]);
 212                        dev_dbg(&pdev->dev,
 213                                        "Setting SysClkReq%dRfClkBuf 0x%X\n",
 214                                        j + 1,
 215                                        pdata->initial_req_buf_config[j]);
 216                        if (ret < 0) {
 217                                dev_err(&pdev->dev,
 218                                        "unable to set sysClkReq%dRfClkBuf: "
 219                                        "%d\n", j + 1, ret);
 220                        }
 221                }
 222        }
 223
 224        return 0;
 225}
 226
 227static int ab8500_sysctrl_remove(struct platform_device *pdev)
 228{
 229        sysctrl_dev = NULL;
 230
 231        if (pm_power_off == ab8500_power_off)
 232                pm_power_off = NULL;
 233
 234        return 0;
 235}
 236
 237static struct platform_driver ab8500_sysctrl_driver = {
 238        .driver = {
 239                .name = "ab8500-sysctrl",
 240                .owner = THIS_MODULE,
 241        },
 242        .probe = ab8500_sysctrl_probe,
 243        .remove = ab8500_sysctrl_remove,
 244};
 245
 246static int __init ab8500_sysctrl_init(void)
 247{
 248        return platform_driver_register(&ab8500_sysctrl_driver);
 249}
 250arch_initcall(ab8500_sysctrl_init);
 251
 252MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
 253MODULE_DESCRIPTION("AB8500 system control driver");
 254MODULE_LICENSE("GPL v2");
 255
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