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 */
u300_pm_poweroff(void)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 */
__u300_init_boardpower(struct platform_device * pdev)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
s365_board_probe(struct platform_device * pdev)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 */
u300_init_boardpower(void)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);
133
