xref: /openbmc/linux/drivers/mfd/ab8500-sysctrl.c (revision cdfce539)
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 char *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 = psy->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &val);
53 
54 		if (!ret && val.intval) {
55 			charger_present = true;
56 			break;
57 		}
58 	}
59 
60 	if (!charger_present)
61 		goto shutdown;
62 
63 	/* Check if battery is known */
64 	psy = power_supply_get_by_name("ab8500_btemp");
65 	if (psy) {
66 		ret = psy->get_property(psy, POWER_SUPPLY_PROP_TECHNOLOGY,
67 					&val);
68 		if (!ret && val.intval != POWER_SUPPLY_TECHNOLOGY_UNKNOWN) {
69 			printk(KERN_INFO
70 			       "Charger \"%s\" is connected with known battery."
71 			       " Rebooting.\n",
72 			       pss[i]);
73 			machine_restart("charging");
74 		}
75 	}
76 
77 shutdown:
78 	sigfillset(&all);
79 
80 	if (!sigprocmask(SIG_BLOCK, &all, &old)) {
81 		(void)ab8500_sysctrl_set(AB8500_STW4500CTRL1,
82 					 AB8500_STW4500CTRL1_SWOFF |
83 					 AB8500_STW4500CTRL1_SWRESET4500N);
84 		(void)sigprocmask(SIG_SETMASK, &old, NULL);
85 	}
86 }
87 
88 /*
89  * Use the AB WD to reset the platform. It will perform a hard
90  * reset instead of a soft reset. Write the reset reason to
91  * the AB before reset, which can be read upon restart.
92  */
93 void ab8500_restart(char mode, const char *cmd)
94 {
95 	struct ab8500_platform_data *plat;
96 	struct ab8500_sysctrl_platform_data *pdata;
97 	u16 reason = 0;
98 	u8 val;
99 
100 	if (sysctrl_dev == NULL) {
101 		pr_err("%s: sysctrl not initialized\n", __func__);
102 		return;
103 	}
104 
105 	plat = dev_get_platdata(sysctrl_dev->parent);
106 	pdata = plat->sysctrl;
107 	if (pdata && pdata->reboot_reason_code)
108 		reason = pdata->reboot_reason_code(cmd);
109 	else
110 		pr_warn("[%s] No reboot reason set. Default reason %d\n",
111 			__func__, reason);
112 
113 	/*
114 	 * Disable RTC alarm, just a precaution so that no alarm
115 	 * is running when WD reset is executed.
116 	 */
117 	abx500_get_register_interruptible(sysctrl_dev, AB8500_RTC,
118 		RTC_CTRL , &val);
119 	abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
120 		RTC_CTRL , (val & ~RTC_ALARM_ENABLE));
121 
122 	/*
123 	 * Android is not using the RTC alarm registers during reboot
124 	 * so we borrow them for writing the reason of reset
125 	 */
126 
127 	/* reason[8 LSB] */
128 	val = reason & 0xFF;
129 	abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
130 		AB8500_ALARM_MIN_LOW , val);
131 
132 	/* reason[8 MSB] */
133 	val = (reason>>8) & 0xFF;
134 	abx500_set_register_interruptible(sysctrl_dev, AB8500_RTC,
135 		AB8500_ALARM_MIN_MID , val);
136 
137 	/* Setting WD timeout to 0 */
138 	ab8500_sysctrl_write(AB8500_MAINWDOGTIMER, 0xFF, 0x0);
139 
140 	/* Setting the parameters to AB8500 WD*/
141 	ab8500_sysctrl_write(AB8500_MAINWDOGCTRL, 0xFF, (AB8500_ENABLE_WD |
142 		AB8500_WD_RESTART_ON_EXPIRE | AB8500_KICK_WD));
143 }
144 
145 static inline bool valid_bank(u8 bank)
146 {
147 	return ((bank == AB8500_SYS_CTRL1_BLOCK) ||
148 		(bank == AB8500_SYS_CTRL2_BLOCK));
149 }
150 
151 int ab8500_sysctrl_read(u16 reg, u8 *value)
152 {
153 	u8 bank;
154 
155 	if (sysctrl_dev == NULL)
156 		return -EINVAL;
157 
158 	bank = (reg >> 8);
159 	if (!valid_bank(bank))
160 		return -EINVAL;
161 
162 	return abx500_get_register_interruptible(sysctrl_dev, bank,
163 		(u8)(reg & 0xFF), value);
164 }
165 EXPORT_SYMBOL(ab8500_sysctrl_read);
166 
167 int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
168 {
169 	u8 bank;
170 
171 	if (sysctrl_dev == NULL)
172 		return -EINVAL;
173 
174 	bank = (reg >> 8);
175 	if (!valid_bank(bank))
176 		return -EINVAL;
177 
178 	return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
179 		(u8)(reg & 0xFF), mask, value);
180 }
181 EXPORT_SYMBOL(ab8500_sysctrl_write);
182 
183 static int ab8500_sysctrl_probe(struct platform_device *pdev)
184 {
185 	struct ab8500 *ab8500 = dev_get_drvdata(pdev->dev.parent);
186 	struct ab8500_platform_data *plat;
187 	struct ab8500_sysctrl_platform_data *pdata;
188 
189 	plat = dev_get_platdata(pdev->dev.parent);
190 
191 	if (!plat)
192 		return -EINVAL;
193 
194 	sysctrl_dev = &pdev->dev;
195 
196 	if (!pm_power_off)
197 		pm_power_off = ab8500_power_off;
198 
199 	pdata = plat->sysctrl;
200 	if (pdata) {
201 		int last, ret, i, j;
202 
203 		if (is_ab8505(ab8500))
204 			last = AB8500_SYSCLKREQ4RFCLKBUF;
205 		else
206 			last = AB8500_SYSCLKREQ8RFCLKBUF;
207 
208 		for (i = AB8500_SYSCLKREQ1RFCLKBUF; i <= last; i++) {
209 			j = i - AB8500_SYSCLKREQ1RFCLKBUF;
210 			ret = ab8500_sysctrl_write(i, 0xff,
211 					pdata->initial_req_buf_config[j]);
212 			dev_dbg(&pdev->dev,
213 					"Setting SysClkReq%dRfClkBuf 0x%X\n",
214 					j + 1,
215 					pdata->initial_req_buf_config[j]);
216 			if (ret < 0) {
217 				dev_err(&pdev->dev,
218 					"unable to set sysClkReq%dRfClkBuf: "
219 					"%d\n", j + 1, ret);
220 			}
221 		}
222 	}
223 
224 	return 0;
225 }
226 
227 static int ab8500_sysctrl_remove(struct platform_device *pdev)
228 {
229 	sysctrl_dev = NULL;
230 
231 	if (pm_power_off == ab8500_power_off)
232 		pm_power_off = NULL;
233 
234 	return 0;
235 }
236 
237 static struct platform_driver ab8500_sysctrl_driver = {
238 	.driver = {
239 		.name = "ab8500-sysctrl",
240 		.owner = THIS_MODULE,
241 	},
242 	.probe = ab8500_sysctrl_probe,
243 	.remove = ab8500_sysctrl_remove,
244 };
245 
246 static int __init ab8500_sysctrl_init(void)
247 {
248 	return platform_driver_register(&ab8500_sysctrl_driver);
249 }
250 arch_initcall(ab8500_sysctrl_init);
251 
252 MODULE_AUTHOR("Mattias Nilsson <mattias.i.nilsson@stericsson.com");
253 MODULE_DESCRIPTION("AB8500 system control driver");
254 MODULE_LICENSE("GPL v2");
255