arch/arm/mach-u300/regulator.c

   1 /*
   2  * arch/arm/mach-u300/regulator.c
   3  *
   4  * Copyright (C) 2009 ST-Ericsson AB
   5  * License terms: GNU General Public License (GPL) version 2
   6  * Handle board-bound regulators and board power not related
   7  * to any devices.
   8  * Author: Linus Walleij <linus.walleij@stericsson.com>
   9  */
  10 #include <linux/device.h>
  11 #include <linux/signal.h>
  12 #include <linux/err.h>
  13 #include <linux/regulator/consumer.h>
  14 /* Those are just for writing in syscon */
  15 #include <linux/io.h>
  16 #include <mach/hardware.h>
  17 #include <mach/syscon.h>
  18
  19 /*
  20  * Regulators that power the board and chip and which are
  21  * not copuled to specific drivers are hogged in these
  22  * instances.
  23  */
  24 static struct regulator *main_power_15;
  25
  26 /*
  27  * This function is used from pm.h to shut down the system by
  28  * resetting all regulators in turn and then disable regulator
  29  * LDO D (main power).
  30  */
  31 void u300_pm_poweroff(void)
  32 {
  33         sigset_t old, all;
  34
  35         sigfillset(&all);
  36         if (!sigprocmask(SIG_BLOCK, &all, &old)) {
  37                 /* Disable LDO D to shut down the system */
  38                 if (main_power_15)
  39                         regulator_disable(main_power_15);
  40                 else
  41                         pr_err("regulator not available to shut down system\n");
  42                 (void) sigprocmask(SIG_SETMASK, &old, NULL);
  43         }
  44         return;
  45 }
  46
  47 /*
  48  * Hog the regulators needed to power up the board.
  49  */
  50 static int __init u300_init_boardpower(void)
  51 {
  52         int err;
  53         u32 val;
  54
  55         pr_info("U300: setting up board power\n");
  56         main_power_15 = regulator_get(NULL, "vana15");
  57         if (IS_ERR(main_power_15)) {
  58                 pr_err("could not get vana15");
  59                 return PTR_ERR(main_power_15);
  60         }
  61         err = regulator_enable(main_power_15);
  62         if (err) {
  63                 pr_err("could not enable vana15\n");
  64                 return err;
  65         }
  66
  67         /*
  68          * On U300 a special system controller register pulls up the DC
  69          * until the vana15 (LDO D) regulator comes up. At this point, all
  70          * regulators are set and we do not need power control via
  71          * DC ON anymore. This function will likely be moved whenever
  72          * the rest of the U300 power management is implemented.
  73          */
  74         pr_info("U300: disable system controller pull-up\n");
  75         val = readw(U300_SYSCON_VBASE + U300_SYSCON_PMCR);
  76         val &= ~U300_SYSCON_PMCR_DCON_ENABLE;
  77         writew(val, U300_SYSCON_VBASE + U300_SYSCON_PMCR);
  78
  79         /* Register globally exported PM poweroff hook */
  80         pm_power_off = u300_pm_poweroff;
  81
  82         return 0;
  83 }
  84
  85 /*
  86  * So at module init time we hog the regulator!
  87  */
  88 module_init(u300_init_boardpower);