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);