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); 262