xref: /openbmc/linux/drivers/mfd/ab8500-sysctrl.c (revision af873fce)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * AB8500 system control driver
4  *
5  * Copyright (C) ST-Ericsson SA 2010
6  * Author: Mattias Nilsson <mattias.i.nilsson@stericsson.com> for ST Ericsson.
7  */
8 
9 #include <linux/err.h>
10 #include <linux/init.h>
11 #include <linux/export.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm.h>
14 #include <linux/reboot.h>
15 #include <linux/signal.h>
16 #include <linux/power_supply.h>
17 #include <linux/mfd/abx500.h>
18 #include <linux/mfd/abx500/ab8500.h>
19 #include <linux/mfd/abx500/ab8500-sysctrl.h>
20 
21 /* RtcCtrl bits */
22 #define AB8500_ALARM_MIN_LOW  0x08
23 #define AB8500_ALARM_MIN_MID 0x09
24 #define RTC_CTRL 0x0B
25 #define RTC_ALARM_ENABLE 0x4
26 
27 static struct device *sysctrl_dev;
28 
ab8500_power_off(void)29 static void ab8500_power_off(void)
30 {
31 	sigset_t old;
32 	sigset_t all;
33 	static const char * const pss[] = {"ab8500_ac", "pm2301", "ab8500_usb"};
34 	int i;
35 	bool charger_present = false;
36 	union power_supply_propval val;
37 	struct power_supply *psy;
38 	int ret;
39 
40 	if (sysctrl_dev == NULL) {
41 		pr_err("%s: sysctrl not initialized\n", __func__);
42 		return;
43 	}
44 
45 	/*
46 	 * If we have a charger connected and we're powering off,
47 	 * reboot into charge-only mode.
48 	 */
49 
50 	for (i = 0; i < ARRAY_SIZE(pss); i++) {
51 		psy = power_supply_get_by_name(pss[i]);
52 		if (!psy)
53 			continue;
54 
55 		ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
56 				&val);
57 		power_supply_put(psy);
58 
59 		if (!ret && val.intval) {
60 			charger_present = true;
61 			break;
62 		}
63 	}
64 
65 	if (!charger_present)
66 		goto shutdown;
67 
68 	/* Check if battery is known */
69 	psy = power_supply_get_by_name("ab8500_btemp");
70 	if (psy) {
71 		ret = power_supply_get_property(psy,
72 				POWER_SUPPLY_PROP_TECHNOLOGY, &val);
73 		if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
74 			pr_info("Charger '%s' is connected with known battery",
75 				pss[i]);
76 			pr_info(" - Rebooting.\n");
77 			machine_restart("charging");
78 		}
79 		power_supply_put(psy);
80 	}
81 
82 shutdown:
83 	sigfillset(&all);
84 
85 	if (!sigprocmask(SIG_BLOCK, &all, &old)) {
86 		(void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
87 					 AB8500_STW4500CTRL1_SWOFF |
88 					 AB8500_STW4500CTRL1_SWRESET4500N);
89 		(void)sigprocmask(SIG_SETMASK, &old, NULL);
90 	}
91 }
92 
valid_bank(u8 bank)93 static inline bool valid_bank(u8 bank)
94 {
95 	return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
96 		(bank == AB8500_SYS_CTRL2_BLOCK));
97 }
98 
ab8500_sysctrl_read(u16 reg,u8 * value)99 int ab8500_sysctrl_read(u16 reg, u8 *value)
100 {
101 	u8 bank;
102 
103 	if (sysctrl_dev == NULL)
104 		return -EPROBE_DEFER;
105 
106 	bank = (reg >> 8);
107 	if (!valid_bank(bank))
108 		return -EINVAL;
109 
110 	return abx500_get_register_interruptible(sysctrl_dev, bank,
111 		(u8)(reg & 0xFF), value);
112 }
113 EXPORT_SYMBOL(ab8500_sysctrl_read);
114 
ab8500_sysctrl_write(u16 reg,u8 mask,u8 value)115 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
116 {
117 	u8 bank;
118 
119 	if (sysctrl_dev == NULL)
120 		return -EPROBE_DEFER;
121 
122 	bank = (reg >> 8);
123 	if (!valid_bank(bank)) {
124 		pr_err("invalid bank\n");
125 		return -EINVAL;
126 	}
127 
128 	return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
129 		(u8)(reg & 0xFF), mask, value);
130 }
131 EXPORT_SYMBOL(ab8500_sysctrl_write);
132 
ab8500_sysctrl_probe(struct platform_device * pdev)133 static int ab8500_sysctrl_probe(struct platform_device *pdev)
134 {
135 	sysctrl_dev = &pdev->dev;
136 
137 	if (!pm_power_off)
138 		pm_power_off = ab8500_power_off;
139 
140 	return 0;
141 }
142 
ab8500_sysctrl_remove(struct platform_device * pdev)143 static int ab8500_sysctrl_remove(struct platform_device *pdev)
144 {
145 	sysctrl_dev = NULL;
146 
147 	if (pm_power_off == ab8500_power_off)
148 		pm_power_off = NULL;
149 
150 	return 0;
151 }
152 
153 static const struct of_device_id ab8500_sysctrl_match[] = {
154 	{ .compatible = "stericsson,ab8500-sysctrl", },
155 	{}
156 };
157 
158 static struct platform_driver ab8500_sysctrl_driver = {
159 	.driver = {
160 		.name = "ab8500-sysctrl",
161 		.of_match_table = ab8500_sysctrl_match,
162 	},
163 	.probe = ab8500_sysctrl_probe,
164 	.remove = ab8500_sysctrl_remove,
165 };
166 
ab8500_sysctrl_init(void)167 static int __init ab8500_sysctrl_init(void)
168 {
169 	return platform_driver_register(&ab8500_sysctrl_driver);
170 }
171 arch_initcall(ab8500_sysctrl_init);
172