LXR linux/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 */
  31static 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 */
  38void 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 */
  57static 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
 106static int __init s365_board_probe(struct platform_device *pdev)
 107{
 108        return __u300_init_boardpower(pdev);
 109}
 110
 111static const struct of_device_id s365_board_match[] = {
 112        { .compatible = "stericsson,s365" },
 113        {},
 114};
 115
 116static 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 */
 126static int __init u300_init_boardpower(void)
 127{
 128        return platform_driver_probe(&s365_board_driver,
 129                                     s365_board_probe);
 130}
 131
 132device_initcall(u300_init_boardpower);
 133