1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * IBM OPAL RTC driver |
4 | * Copyright (C) 2014 IBM |
5 | */ |
6 | |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
8 | |
9 | #define DRVNAME "rtc-opal" |
10 | |
11 | #include <linux/module.h> |
12 | #include <linux/err.h> |
13 | #include <linux/rtc.h> |
14 | #include <linux/delay.h> |
15 | #include <linux/bcd.h> |
16 | #include <linux/platform_device.h> |
17 | #include <linux/of.h> |
18 | #include <asm/opal.h> |
19 | #include <asm/firmware.h> |
20 | |
21 | static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm) |
22 | { |
23 | tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) + |
24 | bcd2bin((y_m_d >> 16) & 0xff)) - 1900; |
25 | tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1; |
26 | tm->tm_mday = bcd2bin(y_m_d & 0xff); |
27 | tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff); |
28 | tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff); |
29 | tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff); |
30 | |
31 | tm->tm_wday = -1; |
32 | } |
33 | |
34 | static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms) |
35 | { |
36 | *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24; |
37 | *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16; |
38 | *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8; |
39 | *y_m_d |= ((u32)bin2bcd(tm->tm_mday)); |
40 | |
41 | *h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56; |
42 | *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48; |
43 | *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40; |
44 | } |
45 | |
46 | static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm) |
47 | { |
48 | s64 rc = OPAL_BUSY; |
49 | int retries = 10; |
50 | u32 y_m_d; |
51 | u64 h_m_s_ms; |
52 | __be32 __y_m_d; |
53 | __be64 __h_m_s_ms; |
54 | |
55 | while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { |
56 | rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); |
57 | if (rc == OPAL_BUSY_EVENT) { |
58 | msleep(msecs: OPAL_BUSY_DELAY_MS); |
59 | opal_poll_events(NULL); |
60 | } else if (rc == OPAL_BUSY) { |
61 | msleep(msecs: OPAL_BUSY_DELAY_MS); |
62 | } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { |
63 | if (retries--) { |
64 | msleep(msecs: 10); /* Wait 10ms before retry */ |
65 | rc = OPAL_BUSY; /* go around again */ |
66 | } |
67 | } |
68 | } |
69 | |
70 | if (rc != OPAL_SUCCESS) |
71 | return -EIO; |
72 | |
73 | y_m_d = be32_to_cpu(__y_m_d); |
74 | h_m_s_ms = be64_to_cpu(__h_m_s_ms); |
75 | opal_to_tm(y_m_d, h_m_s_ms, tm); |
76 | |
77 | return 0; |
78 | } |
79 | |
80 | static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm) |
81 | { |
82 | s64 rc = OPAL_BUSY; |
83 | int retries = 10; |
84 | u32 y_m_d = 0; |
85 | u64 h_m_s_ms = 0; |
86 | |
87 | tm_to_opal(tm, y_m_d: &y_m_d, h_m_s_ms: &h_m_s_ms); |
88 | |
89 | while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { |
90 | rc = opal_rtc_write(y_m_d, h_m_s_ms); |
91 | if (rc == OPAL_BUSY_EVENT) { |
92 | msleep(msecs: OPAL_BUSY_DELAY_MS); |
93 | opal_poll_events(NULL); |
94 | } else if (rc == OPAL_BUSY) { |
95 | msleep(msecs: OPAL_BUSY_DELAY_MS); |
96 | } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { |
97 | if (retries--) { |
98 | msleep(msecs: 10); /* Wait 10ms before retry */ |
99 | rc = OPAL_BUSY; /* go around again */ |
100 | } |
101 | } |
102 | } |
103 | |
104 | return rc == OPAL_SUCCESS ? 0 : -EIO; |
105 | } |
106 | |
107 | /* |
108 | * TPO Timed Power-On |
109 | * |
110 | * TPO get/set OPAL calls care about the hour and min and to make it consistent |
111 | * with the rtc utility time conversion functions, we use the 'u64' to store |
112 | * its value and perform bit shift by 32 before use.. |
113 | */ |
114 | static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) |
115 | { |
116 | __be32 __y_m_d, __h_m; |
117 | struct opal_msg msg; |
118 | int rc, token; |
119 | u64 h_m_s_ms; |
120 | u32 y_m_d; |
121 | |
122 | token = opal_async_get_token_interruptible(); |
123 | if (token < 0) { |
124 | if (token != -ERESTARTSYS) |
125 | pr_err("Failed to get the async token\n" ); |
126 | |
127 | return token; |
128 | } |
129 | |
130 | rc = opal_tpo_read(token, &__y_m_d, &__h_m); |
131 | if (rc != OPAL_ASYNC_COMPLETION) { |
132 | rc = -EIO; |
133 | goto exit; |
134 | } |
135 | |
136 | rc = opal_async_wait_response(token, &msg); |
137 | if (rc) { |
138 | rc = -EIO; |
139 | goto exit; |
140 | } |
141 | |
142 | rc = opal_get_async_rc(msg); |
143 | if (rc != OPAL_SUCCESS) { |
144 | rc = -EIO; |
145 | goto exit; |
146 | } |
147 | |
148 | y_m_d = be32_to_cpu(__y_m_d); |
149 | h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); |
150 | |
151 | /* check if no alarm is set */ |
152 | if (y_m_d == 0 && h_m_s_ms == 0) { |
153 | pr_debug("No alarm is set\n" ); |
154 | rc = -ENOENT; |
155 | goto exit; |
156 | } else { |
157 | pr_debug("Alarm set to %x %llx\n" , y_m_d, h_m_s_ms); |
158 | } |
159 | |
160 | opal_to_tm(y_m_d, h_m_s_ms, tm: &alarm->time); |
161 | |
162 | exit: |
163 | opal_async_release_token(token); |
164 | return rc; |
165 | } |
166 | |
167 | /* Set Timed Power-On */ |
168 | static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) |
169 | { |
170 | u64 h_m_s_ms = 0; |
171 | struct opal_msg msg; |
172 | u32 y_m_d = 0; |
173 | int token, rc; |
174 | |
175 | /* if alarm is enabled */ |
176 | if (alarm->enabled) { |
177 | tm_to_opal(tm: &alarm->time, y_m_d: &y_m_d, h_m_s_ms: &h_m_s_ms); |
178 | pr_debug("Alarm set to %x %llx\n" , y_m_d, h_m_s_ms); |
179 | |
180 | } else { |
181 | pr_debug("Alarm getting disabled\n" ); |
182 | } |
183 | |
184 | token = opal_async_get_token_interruptible(); |
185 | if (token < 0) { |
186 | if (token != -ERESTARTSYS) |
187 | pr_err("Failed to get the async token\n" ); |
188 | |
189 | return token; |
190 | } |
191 | |
192 | /* TPO, we care about hour and minute */ |
193 | rc = opal_tpo_write(token, y_m_d, |
194 | (u32)((h_m_s_ms >> 32) & 0xffff0000)); |
195 | if (rc != OPAL_ASYNC_COMPLETION) { |
196 | rc = -EIO; |
197 | goto exit; |
198 | } |
199 | |
200 | rc = opal_async_wait_response(token, &msg); |
201 | if (rc) { |
202 | rc = -EIO; |
203 | goto exit; |
204 | } |
205 | |
206 | rc = opal_get_async_rc(msg); |
207 | if (rc != OPAL_SUCCESS) |
208 | rc = -EIO; |
209 | |
210 | exit: |
211 | opal_async_release_token(token); |
212 | return rc; |
213 | } |
214 | |
215 | static int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled) |
216 | { |
217 | struct rtc_wkalrm alarm = { .enabled = 0 }; |
218 | |
219 | /* |
220 | * TPO is automatically enabled when opal_set_tpo_time() is called with |
221 | * non-zero rtc-time. We only handle disable case which needs to be |
222 | * explicitly told to opal. |
223 | */ |
224 | return enabled ? 0 : opal_set_tpo_time(dev, alarm: &alarm); |
225 | } |
226 | |
227 | static const struct rtc_class_ops opal_rtc_ops = { |
228 | .read_time = opal_get_rtc_time, |
229 | .set_time = opal_set_rtc_time, |
230 | .read_alarm = opal_get_tpo_time, |
231 | .set_alarm = opal_set_tpo_time, |
232 | .alarm_irq_enable = opal_tpo_alarm_irq_enable, |
233 | }; |
234 | |
235 | static int opal_rtc_probe(struct platform_device *pdev) |
236 | { |
237 | struct rtc_device *rtc; |
238 | |
239 | rtc = devm_rtc_allocate_device(dev: &pdev->dev); |
240 | if (IS_ERR(ptr: rtc)) |
241 | return PTR_ERR(ptr: rtc); |
242 | |
243 | if (pdev->dev.of_node && |
244 | (of_property_read_bool(np: pdev->dev.of_node, propname: "wakeup-source" ) || |
245 | of_property_read_bool(np: pdev->dev.of_node, propname: "has-tpo" )/* legacy */)) |
246 | device_set_wakeup_capable(dev: &pdev->dev, capable: true); |
247 | else |
248 | clear_bit(RTC_FEATURE_ALARM, addr: rtc->features); |
249 | |
250 | rtc->ops = &opal_rtc_ops; |
251 | rtc->range_min = RTC_TIMESTAMP_BEGIN_0000; |
252 | rtc->range_max = RTC_TIMESTAMP_END_9999; |
253 | clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, addr: rtc->features); |
254 | |
255 | return devm_rtc_register_device(rtc); |
256 | } |
257 | |
258 | static const struct of_device_id opal_rtc_match[] = { |
259 | { |
260 | .compatible = "ibm,opal-rtc" , |
261 | }, |
262 | { } |
263 | }; |
264 | MODULE_DEVICE_TABLE(of, opal_rtc_match); |
265 | |
266 | static const struct platform_device_id opal_rtc_driver_ids[] = { |
267 | { |
268 | .name = "opal-rtc" , |
269 | }, |
270 | { } |
271 | }; |
272 | MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids); |
273 | |
274 | static struct platform_driver opal_rtc_driver = { |
275 | .probe = opal_rtc_probe, |
276 | .id_table = opal_rtc_driver_ids, |
277 | .driver = { |
278 | .name = DRVNAME, |
279 | .of_match_table = opal_rtc_match, |
280 | }, |
281 | }; |
282 | |
283 | static int __init opal_rtc_init(void) |
284 | { |
285 | if (!firmware_has_feature(FW_FEATURE_OPAL)) |
286 | return -ENODEV; |
287 | |
288 | return platform_driver_register(&opal_rtc_driver); |
289 | } |
290 | |
291 | static void __exit opal_rtc_exit(void) |
292 | { |
293 | platform_driver_unregister(&opal_rtc_driver); |
294 | } |
295 | |
296 | MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>" ); |
297 | MODULE_DESCRIPTION("IBM OPAL RTC driver" ); |
298 | MODULE_LICENSE("GPL" ); |
299 | |
300 | module_init(opal_rtc_init); |
301 | module_exit(opal_rtc_exit); |
302 | |