xref: /openbmc/linux/drivers/mfd/ab8500-sysctrl.c (revision 293d5b43)
1 /*
2  * Copyright (C) ST-Ericsson SA 2010
3  * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
4  * License terms: GNU General Public License (GPL) version 2
5  */
6 
7 #include <linux/err.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/pm.h>
11 #include <linux/reboot.h>
12 #include <linux/signal.h>
13 #include <linux/power_supply.h>
14 #include <linux/mfd/abx500.h>
15 #include <linux/mfd/abx500/ab8500.h>
16 #include <linux/mfd/abx500/ab8500-sysctrl.h>
17 
18 /* RtcCtrl bits */
19 #define AB8500_ALARM_MIN_LOW  0x08
20 #define AB8500_ALARM_MIN_MID 0x09
21 #define RTC_CTRL 0x0B
22 #define RTC_ALARM_ENABLE 0x4
23 
24 static struct device *sysctrl_dev;
25 
26 static void ab8500_power_off(void)
27 {
28 	sigset_t old;
29 	sigset_t all;
30 	static const char * const pss[] = {"ab8500_ac", "pm2301", "ab8500_usb"};
31 	int i;
32 	bool charger_present = false;
33 	union power_supply_propval val;
34 	struct power_supply *psy;
35 	int ret;
36 
37 	if (sysctrl_dev == NULL) {
38 		pr_err("%s: sysctrl not initialized\n", __func__);
39 		return;
40 	}
41 
42 	/*
43 	 * If we have a charger connected and we're powering off,
44 	 * reboot into charge-only mode.
45 	 */
46 
47 	for (i = 0; i < ARRAY_SIZE(pss); i++) {
48 		psy = power_supply_get_by_name(pss[i]);
49 		if (!psy)
50 			continue;
51 
52 		ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
53 				&val);
54 		power_supply_put(psy);
55 
56 		if (!ret && val.intval) {
57 			charger_present = true;
58 			break;
59 		}
60 	}
61 
62 	if (!charger_present)
63 		goto shutdown;
64 
65 	/* Check if battery is known */
66 	psy = power_supply_get_by_name("ab8500_btemp");
67 	if (psy) {
68 		ret = power_supply_get_property(psy,
69 				POWER_SUPPLY_PROP_TECHNOLOGY, &val);
70 		if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
71 			pr_info("Charger '%s' is connected with known battery",
72 				pss[i]);
73 			pr_info(" - Rebooting.\n");
74 			machine_restart("charging");
75 		}
76 		power_supply_put(psy);
77 	}
78 
79 shutdown:
80 	sigfillset(&all);
81 
82 	if (!sigprocmask(SIG_BLOCK, &all, &old)) {
83 		(void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
84 					 AB8500_STW4500CTRL1_SWOFF |
85 					 AB8500_STW4500CTRL1_SWRESET4500N);
86 		(void)sigprocmask(SIG_SETMASK, &old, NULL);
87 	}
88 }
89 
90 static inline bool valid_bank(u8 bank)
91 {
92 	return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
93 		(bank == AB8500_SYS_CTRL2_BLOCK));
94 }
95 
96 int ab8500_sysctrl_read(u16 reg, u8 *value)
97 {
98 	u8 bank;
99 
100 	if (sysctrl_dev == NULL)
101 		return -EINVAL;
102 
103 	bank = (reg >> 8);
104 	if (!valid_bank(bank))
105 		return -EINVAL;
106 
107 	return abx500_get_register_interruptible(sysctrl_dev, bank,
108 		(u8)(reg & 0xFF), value);
109 }
110 EXPORT_SYMBOL(ab8500_sysctrl_read);
111 
112 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
113 {
114 	u8 bank;
115 
116 	if (sysctrl_dev == NULL)
117 		return -EINVAL;
118 
119 	bank = (reg >> 8);
120 	if (!valid_bank(bank))
121 		return -EINVAL;
122 
123 	return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
124 		(u8)(reg & 0xFF), mask, value);
125 }
126 EXPORT_SYMBOL(ab8500_sysctrl_write);
127 
128 static int ab8500_sysctrl_probe(struct platform_device *pdev)
129 {
130 	sysctrl_dev = &pdev->dev;
131 
132 	if (!pm_power_off)
133 		pm_power_off = ab8500_power_off;
134 
135 	return 0;
136 }
137 
138 static int ab8500_sysctrl_remove(struct platform_device *pdev)
139 {
140 	sysctrl_dev = NULL;
141 
142 	if (pm_power_off == ab8500_power_off)
143 		pm_power_off = NULL;
144 
145 	return 0;
146 }
147 
148 static struct platform_driver ab8500_sysctrl_driver = {
149 	.driver = {
150 		.name = "ab8500-sysctrl",
151 	},
152 	.probe = ab8500_sysctrl_probe,
153 	.remove = ab8500_sysctrl_remove,
154 };
155 
156 static int __init ab8500_sysctrl_init(void)
157 {
158 	return platform_driver_register(&ab8500_sysctrl_driver);
159 }
160 arch_initcall(ab8500_sysctrl_init);
161 
162 MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
163 MODULE_DESCRIPTION("AB8500 system control driver");
164 MODULE_LICENSE("GPL v2");
165