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 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
  77 shutdown:
  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  */
  93 void 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
 145 static inline bool valid_bank(u8 bank)
 146 {
 147         return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
 148                 (bank == AB8500_SYS_CTRL2_BLOCK));
 149 }
 150
 151 int 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 }
 165 EXPORT_SYMBOL(ab8500_sysctrl_read);
 166
 167 int 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 }
 181 EXPORT_SYMBOL(ab8500_sysctrl_write);
 182
 183 static 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
 227 static 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
 237 static 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
 246 static int __init ab8500_sysctrl_init(void)
 247 {
 248         return platform_driver_register(&ab8500_sysctrl_driver);
 249 }
 250 arch_initcall(ab8500_sysctrl_init);
 251
 252 MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
 253 MODULE_DESCRIPTION("AB8500 system control driver");
 254 MODULE_LICENSE("GPL v2");