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 static struct device *sysctrl_dev;
  19
  20 void ab8500_power_off(void)
  21 {
  22         sigset_t old;
  23         sigset_t all;
  24         static char *pss[] = {"ab8500_ac", "ab8500_usb"};
  25         int i;
  26         bool charger_present = false;
  27         union power_supply_propval val;
  28         struct power_supply *psy;
  29         int ret;
  30
  31         /*
  32          * If we have a charger connected and we're powering off,
  33          * reboot into charge-only mode.
  34          */
  35
  36         for (i = 0; i < ARRAY_SIZE(pss); i++) {
  37                 psy = power_supply_get_by_name(pss[i]);
  38                 if (!psy)
  39                         continue;
  40
  41                 ret = psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &val);
  42
  43                 if (!ret && val.intval) {
  44                         charger_present = true;
  45                         break;
  46                 }
  47         }
  48
  49         if (!charger_present)
  50                 goto shutdown;
  51
  52         /* Check if battery is known */
  53         psy = power_supply_get_by_name("ab8500_btemp");
  54         if (psy) {
  55                 ret = psy->get_property(psy, POWER_SUPPLY_PROP_TECHNOLOGY,
  56                                         &val);
  57                 if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
  58                         printk(KERN_INFO
  59                                "Charger \"%s\" is connected with known battery."
  60                                " Rebooting.\n",
  61                                pss[i]);
  62                         machine_restart("charging");
  63                 }
  64         }
  65
  66 shutdown:
  67         sigfillset(&all);
  68
  69         if (!sigprocmask(SIG_BLOCK, &all, &old)) {
  70                 (void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
  71                                          AB8500_STW4500CTRL1_SWOFF |
  72                                          AB8500_STW4500CTRL1_SWRESET4500N);
  73                 (void)sigprocmask(SIG_SETMASK, &old, NULL);
  74         }
  75 }
  76
  77 static inline bool valid_bank(u8 bank)
  78 {
  79         return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
  80                 (bank == AB8500_SYS_CTRL2_BLOCK));
  81 }
  82
  83 int ab8500_sysctrl_read(u16 reg, u8 *value)
  84 {
  85         u8 bank;
  86
  87         if (sysctrl_dev == NULL)
  88                 return -EAGAIN;
  89
  90         bank = (reg >> 8);
  91         if (!valid_bank(bank))
  92                 return -EINVAL;
  93
  94         return abx500_get_register_interruptible(sysctrl_dev, bank,
  95                 (u8)(reg & 0xFF), value);
  96 }
  97 EXPORT_SYMBOL(ab8500_sysctrl_read);
  98
  99 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
 100 {
 101         u8 bank;
 102
 103         if (sysctrl_dev == NULL)
 104                 return -EAGAIN;
 105
 106         bank = (reg >> 8);
 107         if (!valid_bank(bank))
 108                 return -EINVAL;
 109
 110         return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
 111                 (u8)(reg & 0xFF), mask, value);
 112 }
 113 EXPORT_SYMBOL(ab8500_sysctrl_write);
 114
 115 static int ab8500_sysctrl_probe(struct platform_device *pdev)
 116 {
 117         struct ab8500_platform_data *plat;
 118         struct ab8500_sysctrl_platform_data *pdata;
 119
 120         sysctrl_dev = &pdev->dev;
 121         plat = dev_get_platdata(pdev->dev.parent);
 122         if (plat->pm_power_off)
 123                 pm_power_off = ab8500_power_off;
 124
 125         pdata = plat->sysctrl;
 126
 127         if (pdata) {
 128                 int ret, i, j;
 129
 130                 for (i = AB8500_SYSCLKREQ1RFCLKBUF;
 131                      i <= AB8500_SYSCLKREQ8RFCLKBUF; i++) {
 132                         j = i - AB8500_SYSCLKREQ1RFCLKBUF;
 133                         ret = ab8500_sysctrl_write(i, 0xff,
 134                                                    pdata->initial_req_buf_config[j]);
 135                         dev_dbg(&pdev->dev,
 136                                 "Setting SysClkReq%dRfClkBuf 0x%X\n",
 137                                 j + 1,
 138                                 pdata->initial_req_buf_config[j]);
 139                         if (ret < 0) {
 140                                 dev_err(&pdev->dev,
 141                                         "unable to set sysClkReq%dRfClkBuf: "
 142                                         "%d\n", j + 1, ret);
 143                         }
 144                 }
 145         }
 146
 147         return 0;
 148 }
 149
 150 static int ab8500_sysctrl_remove(struct platform_device *pdev)
 151 {
 152         sysctrl_dev = NULL;
 153         return 0;
 154 }
 155
 156 static struct platform_driver ab8500_sysctrl_driver = {
 157         .driver = {
 158                 .name = "ab8500-sysctrl",
 159                 .owner = THIS_MODULE,
 160         },
 161         .probe = ab8500_sysctrl_probe,
 162         .remove = ab8500_sysctrl_remove,
 163 };
 164
 165 static int __init ab8500_sysctrl_init(void)
 166 {
 167         return platform_driver_register(&ab8500_sysctrl_driver);
 168 }
 169 subsys_initcall(ab8500_sysctrl_init);
 170
 171 MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
 172 MODULE_DESCRIPTION("AB8500 system control driver");
 173 MODULE_LICENSE("GPL v2");