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/of.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regulator/machine.h>
  17 #include <linux/regulator/consumer.h>
  18 #include <linux/mfd/syscon.h>
  19 #include <linux/regmap.h>
  20
  21 /* Power Management Control 16bit (R/W) */
  22 #define U300_SYSCON_PMCR                                        (0x50)
  23 #define U300_SYSCON_PMCR_DCON_ENABLE                            (0x0002)
  24 #define U300_SYSCON_PMCR_PWR_MGNT_ENABLE                        (0x0001)
  25
  26 /*
  27  * Regulators that power the board and chip and which are
  28  * not copuled to specific drivers are hogged in these
  29  * instances.
  30  */
  31 static struct regulator *main_power_15;
  32
  33 /*
  34  * This function is used from pm.h to shut down the system by
  35  * resetting all regulators in turn and then disable regulator
  36  * LDO D (main power).
  37  */
  38 void u300_pm_poweroff(void)
  39 {
  40         sigset_t old, all;
  41
  42         sigfillset(&all);
  43         if (!sigprocmask(SIG_BLOCK, &all, &old)) {
  44                 /* Disable LDO D to shut down the system */
  45                 if (main_power_15)
  46                         regulator_disable(main_power_15);
  47                 else
  48                         pr_err("regulator not available to shut down system\n");
  49                 (void) sigprocmask(SIG_SETMASK, &old, NULL);
  50         }
  51         return;
  52 }
  53
  54 /*
  55  * Hog the regulators needed to power up the board.
  56  */
  57 static int __init __u300_init_boardpower(struct platform_device *pdev)
  58 {
  59         struct device_node *np = pdev->dev.of_node;
  60         struct device_node *syscon_np;
  61         struct regmap *regmap;
  62         int err;
  63
  64         pr_info("U300: setting up board power\n");
  65
  66         syscon_np = of_parse_phandle(np, "syscon", 0);
  67         if (!syscon_np) {
  68                 pr_crit("U300: no syscon node\n");
  69                 return -ENODEV;
  70         }
  71         regmap = syscon_node_to_regmap(syscon_np);
  72         if (IS_ERR(regmap)) {
  73                 pr_crit("U300: could not locate syscon regmap\n");
  74                 return PTR_ERR(regmap);
  75         }
  76
  77         main_power_15 = regulator_get(&pdev->dev, "vana15");
  78
  79         if (IS_ERR(main_power_15)) {
  80                 pr_err("could not get vana15");
  81                 return PTR_ERR(main_power_15);
  82         }
  83         err = regulator_enable(main_power_15);
  84         if (err) {
  85                 pr_err("could not enable vana15\n");
  86                 return err;
  87         }
  88
  89         /*
  90          * On U300 a special system controller register pulls up the DC
  91          * until the vana15 (LDO D) regulator comes up. At this point, all
  92          * regulators are set and we do not need power control via
  93          * DC ON anymore. This function will likely be moved whenever
  94          * the rest of the U300 power management is implemented.
  95          */
  96         pr_info("U300: disable system controller pull-up\n");
  97         regmap_update_bits(regmap, U300_SYSCON_PMCR,
  98                            U300_SYSCON_PMCR_DCON_ENABLE, 0);
  99
 100         /* Register globally exported PM poweroff hook */
 101         pm_power_off = u300_pm_poweroff;
 102
 103         return 0;
 104 }
 105
 106 static int __init s365_board_probe(struct platform_device *pdev)
 107 {
 108         return __u300_init_boardpower(pdev);
 109 }
 110
 111 static const struct of_device_id s365_board_match[] = {
 112         { .compatible = "stericsson,s365" },
 113         {},
 114 };
 115
 116 static struct platform_driver s365_board_driver = {
 117         .driver         = {
 118                 .name   = "s365-board",
 119                 .of_match_table = s365_board_match,
 120         },
 121 };
 122
 123 /*
 124  * So at module init time we hog the regulator!
 125  */
 126 static int __init u300_init_boardpower(void)
 127 {
 128         return platform_driver_probe(&s365_board_driver,
 129                                      s365_board_probe);
 130 }
 131
 132 device_initcall(u300_init_boardpower);