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1 | /* |
2 | * IBM OPAL RTC driver | |
3 | * Copyright (C) 2014 IBM | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. | |
17 | */ | |
18 | ||
19 | #define DRVNAME "rtc-opal" | |
20 | #define pr_fmt(fmt) DRVNAME ": " fmt | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/err.h> | |
24 | #include <linux/rtc.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/bcd.h> | |
27 | #include <linux/platform_device.h> | |
28 | #include <linux/of.h> | |
29 | #include <asm/opal.h> | |
30 | #include <asm/firmware.h> | |
31 | ||
32 | static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm) | |
33 | { | |
34 | tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) + | |
35 | bcd2bin((y_m_d >> 16) & 0xff)) - 1900; | |
36 | tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1; | |
37 | tm->tm_mday = bcd2bin(y_m_d & 0xff); | |
38 | tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff); | |
39 | tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff); | |
40 | tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff); | |
41 | ||
42 | GregorianDay(tm); | |
43 | } | |
44 | ||
45 | static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms) | |
46 | { | |
47 | *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24; | |
48 | *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16; | |
49 | *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8; | |
50 | *y_m_d |= ((u32)bin2bcd(tm->tm_mday)); | |
51 | ||
52 | *h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56; | |
53 | *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48; | |
54 | *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40; | |
55 | } | |
56 | ||
57 | static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm) | |
58 | { | |
59 | long rc = OPAL_BUSY; | |
60 | u32 y_m_d; | |
61 | u64 h_m_s_ms; | |
62 | __be32 __y_m_d; | |
63 | __be64 __h_m_s_ms; | |
64 | ||
65 | while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { | |
66 | rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); | |
67 | if (rc == OPAL_BUSY_EVENT) | |
68 | opal_poll_events(NULL); | |
69 | else | |
70 | msleep(10); | |
71 | } | |
72 | ||
73 | if (rc != OPAL_SUCCESS) | |
74 | return -EIO; | |
75 | ||
76 | y_m_d = be32_to_cpu(__y_m_d); | |
77 | h_m_s_ms = be64_to_cpu(__h_m_s_ms); | |
78 | opal_to_tm(y_m_d, h_m_s_ms, tm); | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm) | |
84 | { | |
85 | long rc = OPAL_BUSY; | |
86 | u32 y_m_d = 0; | |
87 | u64 h_m_s_ms = 0; | |
88 | ||
89 | tm_to_opal(tm, &y_m_d, &h_m_s_ms); | |
90 | while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { | |
91 | rc = opal_rtc_write(y_m_d, h_m_s_ms); | |
92 | if (rc == OPAL_BUSY_EVENT) | |
93 | opal_poll_events(NULL); | |
94 | else | |
95 | msleep(10); | |
96 | } | |
97 | ||
98 | return rc == OPAL_SUCCESS ? 0 : -EIO; | |
99 | } | |
100 | ||
101 | /* | |
102 | * TPO Timed Power-On | |
103 | * | |
104 | * TPO get/set OPAL calls care about the hour and min and to make it consistent | |
105 | * with the rtc utility time conversion functions, we use the 'u64' to store | |
106 | * its value and perform bit shift by 32 before use.. | |
107 | */ | |
108 | static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) | |
109 | { | |
110 | __be32 __y_m_d, __h_m; | |
111 | struct opal_msg msg; | |
112 | int rc, token; | |
113 | u64 h_m_s_ms; | |
114 | u32 y_m_d; | |
115 | ||
116 | token = opal_async_get_token_interruptible(); | |
117 | if (token < 0) { | |
118 | if (token != -ERESTARTSYS) | |
119 | pr_err("Failed to get the async token\n"); | |
120 | ||
121 | return token; | |
122 | } | |
123 | ||
124 | rc = opal_tpo_read(token, &__y_m_d, &__h_m); | |
125 | if (rc != OPAL_ASYNC_COMPLETION) { | |
126 | rc = -EIO; | |
127 | goto exit; | |
128 | } | |
129 | ||
130 | rc = opal_async_wait_response(token, &msg); | |
131 | if (rc) { | |
132 | rc = -EIO; | |
133 | goto exit; | |
134 | } | |
135 | ||
136 | rc = be64_to_cpu(msg.params[1]); | |
137 | if (rc != OPAL_SUCCESS) { | |
138 | rc = -EIO; | |
139 | goto exit; | |
140 | } | |
141 | ||
142 | y_m_d = be32_to_cpu(__y_m_d); | |
143 | h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); | |
144 | opal_to_tm(y_m_d, h_m_s_ms, &alarm->time); | |
145 | ||
146 | exit: | |
147 | opal_async_release_token(token); | |
148 | return rc; | |
149 | } | |
150 | ||
151 | /* Set Timed Power-On */ | |
152 | static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) | |
153 | { | |
154 | u64 h_m_s_ms = 0, token; | |
155 | struct opal_msg msg; | |
156 | u32 y_m_d = 0; | |
157 | int rc; | |
158 | ||
159 | tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms); | |
160 | ||
161 | token = opal_async_get_token_interruptible(); | |
162 | if (token < 0) { | |
163 | if (token != -ERESTARTSYS) | |
164 | pr_err("Failed to get the async token\n"); | |
165 | ||
166 | return token; | |
167 | } | |
168 | ||
169 | /* TPO, we care about hour and minute */ | |
170 | rc = opal_tpo_write(token, y_m_d, | |
171 | (u32)((h_m_s_ms >> 32) & 0xffff0000)); | |
172 | if (rc != OPAL_ASYNC_COMPLETION) { | |
173 | rc = -EIO; | |
174 | goto exit; | |
175 | } | |
176 | ||
177 | rc = opal_async_wait_response(token, &msg); | |
178 | if (rc) { | |
179 | rc = -EIO; | |
180 | goto exit; | |
181 | } | |
182 | ||
183 | rc = be64_to_cpu(msg.params[1]); | |
184 | if (rc != OPAL_SUCCESS) | |
185 | rc = -EIO; | |
186 | ||
187 | exit: | |
188 | opal_async_release_token(token); | |
189 | return rc; | |
190 | } | |
191 | ||
192 | static const struct rtc_class_ops opal_rtc_ops = { | |
193 | .read_time = opal_get_rtc_time, | |
194 | .set_time = opal_set_rtc_time, | |
195 | .read_alarm = opal_get_tpo_time, | |
196 | .set_alarm = opal_set_tpo_time, | |
197 | }; | |
198 | ||
199 | static int opal_rtc_probe(struct platform_device *pdev) | |
200 | { | |
201 | struct rtc_device *rtc; | |
202 | ||
203 | if (pdev->dev.of_node && of_get_property(pdev->dev.of_node, "has-tpo", | |
204 | NULL)) | |
205 | device_set_wakeup_capable(&pdev->dev, true); | |
206 | ||
207 | rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops, | |
208 | THIS_MODULE); | |
209 | if (IS_ERR(rtc)) | |
210 | return PTR_ERR(rtc); | |
211 | ||
212 | rtc->uie_unsupported = 1; | |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
217 | static const struct of_device_id opal_rtc_match[] = { | |
218 | { | |
219 | .compatible = "ibm,opal-rtc", | |
220 | }, | |
221 | { } | |
222 | }; | |
223 | MODULE_DEVICE_TABLE(of, opal_rtc_match); | |
224 | ||
225 | static const struct platform_device_id opal_rtc_driver_ids[] = { | |
226 | { | |
227 | .name = "opal-rtc", | |
228 | }, | |
229 | { } | |
230 | }; | |
231 | MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids); | |
232 | ||
233 | static struct platform_driver opal_rtc_driver = { | |
234 | .probe = opal_rtc_probe, | |
235 | .id_table = opal_rtc_driver_ids, | |
236 | .driver = { | |
237 | .name = DRVNAME, | |
238 | .owner = THIS_MODULE, | |
239 | .of_match_table = opal_rtc_match, | |
240 | }, | |
241 | }; | |
242 | ||
243 | static int __init opal_rtc_init(void) | |
244 | { | |
245 | if (!firmware_has_feature(FW_FEATURE_OPAL)) | |
246 | return -ENODEV; | |
247 | ||
248 | return platform_driver_register(&opal_rtc_driver); | |
249 | } | |
250 | ||
251 | static void __exit opal_rtc_exit(void) | |
252 | { | |
253 | platform_driver_unregister(&opal_rtc_driver); | |
254 | } | |
255 | ||
256 | MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); | |
257 | MODULE_DESCRIPTION("IBM OPAL RTC driver"); | |
258 | MODULE_LICENSE("GPL"); | |
259 | ||
260 | module_init(opal_rtc_init); | |
261 | module_exit(opal_rtc_exit); |