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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #define DRVNAME "rtc-opal" 22 23 #include <linux/module.h> 24 #include <linux/err.h> 25 #include <linux/rtc.h> 26 #include <linux/delay.h> 27 #include <linux/bcd.h> 28 #include <linux/platform_device.h> 29 #include <linux/of.h> 30 #include <asm/opal.h> 31 #include <asm/firmware.h> 32 33 static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm) 34 { 35 tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) + 36 bcd2bin((y_m_d >> 16) & 0xff)) - 1900; 37 tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1; 38 tm->tm_mday = bcd2bin(y_m_d & 0xff); 39 tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff); 40 tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff); 41 tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff); 42 43 tm->tm_wday = -1; 44 } 45 46 static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms) 47 { 48 *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24; 49 *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16; 50 *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8; 51 *y_m_d |= ((u32)bin2bcd(tm->tm_mday)); 52 53 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56; 54 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48; 55 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40; 56 } 57 58 static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm) 59 { 60 long rc = OPAL_BUSY; 61 u32 y_m_d; 62 u64 h_m_s_ms; 63 __be32 __y_m_d; 64 __be64 __h_m_s_ms; 65 66 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 67 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); 68 if (rc == OPAL_BUSY_EVENT) 69 opal_poll_events(NULL); 70 else 71 msleep(10); 72 } 73 74 if (rc != OPAL_SUCCESS) 75 return -EIO; 76 77 y_m_d = be32_to_cpu(__y_m_d); 78 h_m_s_ms = be64_to_cpu(__h_m_s_ms); 79 opal_to_tm(y_m_d, h_m_s_ms, tm); 80 81 return 0; 82 } 83 84 static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm) 85 { 86 long rc = OPAL_BUSY; 87 u32 y_m_d = 0; 88 u64 h_m_s_ms = 0; 89 90 tm_to_opal(tm, &y_m_d, &h_m_s_ms); 91 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 92 rc = opal_rtc_write(y_m_d, h_m_s_ms); 93 if (rc == OPAL_BUSY_EVENT) 94 opal_poll_events(NULL); 95 else 96 msleep(10); 97 } 98 99 return rc == OPAL_SUCCESS ? 0 : -EIO; 100 } 101 102 /* 103 * TPO Timed Power-On 104 * 105 * TPO get/set OPAL calls care about the hour and min and to make it consistent 106 * with the rtc utility time conversion functions, we use the 'u64' to store 107 * its value and perform bit shift by 32 before use.. 108 */ 109 static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 110 { 111 __be32 __y_m_d, __h_m; 112 struct opal_msg msg; 113 int rc, token; 114 u64 h_m_s_ms; 115 u32 y_m_d; 116 117 token = opal_async_get_token_interruptible(); 118 if (token < 0) { 119 if (token != -ERESTARTSYS) 120 pr_err("Failed to get the async token\n"); 121 122 return token; 123 } 124 125 rc = opal_tpo_read(token, &__y_m_d, &__h_m); 126 if (rc != OPAL_ASYNC_COMPLETION) { 127 rc = -EIO; 128 goto exit; 129 } 130 131 rc = opal_async_wait_response(token, &msg); 132 if (rc) { 133 rc = -EIO; 134 goto exit; 135 } 136 137 rc = be64_to_cpu(msg.params[1]); 138 if (rc != OPAL_SUCCESS) { 139 rc = -EIO; 140 goto exit; 141 } 142 143 y_m_d = be32_to_cpu(__y_m_d); 144 h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); 145 opal_to_tm(y_m_d, h_m_s_ms, &alarm->time); 146 147 exit: 148 opal_async_release_token(token); 149 return rc; 150 } 151 152 /* Set Timed Power-On */ 153 static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 154 { 155 u64 h_m_s_ms = 0; 156 struct opal_msg msg; 157 u32 y_m_d = 0; 158 int token, rc; 159 160 tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms); 161 162 token = opal_async_get_token_interruptible(); 163 if (token < 0) { 164 if (token != -ERESTARTSYS) 165 pr_err("Failed to get the async token\n"); 166 167 return token; 168 } 169 170 /* TPO, we care about hour and minute */ 171 rc = opal_tpo_write(token, y_m_d, 172 (u32)((h_m_s_ms >> 32) & 0xffff0000)); 173 if (rc != OPAL_ASYNC_COMPLETION) { 174 rc = -EIO; 175 goto exit; 176 } 177 178 rc = opal_async_wait_response(token, &msg); 179 if (rc) { 180 rc = -EIO; 181 goto exit; 182 } 183 184 rc = be64_to_cpu(msg.params[1]); 185 if (rc != OPAL_SUCCESS) 186 rc = -EIO; 187 188 exit: 189 opal_async_release_token(token); 190 return rc; 191 } 192 193 static struct rtc_class_ops opal_rtc_ops = { 194 .read_time = opal_get_rtc_time, 195 .set_time = opal_set_rtc_time, 196 }; 197 198 static int opal_rtc_probe(struct platform_device *pdev) 199 { 200 struct rtc_device *rtc; 201 202 if (pdev->dev.of_node && 203 (of_property_read_bool(pdev->dev.of_node, "wakeup-source") || 204 of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */)) { 205 device_set_wakeup_capable(&pdev->dev, true); 206 opal_rtc_ops.read_alarm = opal_get_tpo_time; 207 opal_rtc_ops.set_alarm = opal_set_tpo_time; 208 } 209 210 rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops, 211 THIS_MODULE); 212 if (IS_ERR(rtc)) 213 return PTR_ERR(rtc); 214 215 rtc->uie_unsupported = 1; 216 217 return 0; 218 } 219 220 static const struct of_device_id opal_rtc_match[] = { 221 { 222 .compatible = "ibm,opal-rtc", 223 }, 224 { } 225 }; 226 MODULE_DEVICE_TABLE(of, opal_rtc_match); 227 228 static const struct platform_device_id opal_rtc_driver_ids[] = { 229 { 230 .name = "opal-rtc", 231 }, 232 { } 233 }; 234 MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids); 235 236 static struct platform_driver opal_rtc_driver = { 237 .probe = opal_rtc_probe, 238 .id_table = opal_rtc_driver_ids, 239 .driver = { 240 .name = DRVNAME, 241 .of_match_table = opal_rtc_match, 242 }, 243 }; 244 245 static int __init opal_rtc_init(void) 246 { 247 if (!firmware_has_feature(FW_FEATURE_OPAL)) 248 return -ENODEV; 249 250 return platform_driver_register(&opal_rtc_driver); 251 } 252 253 static void __exit opal_rtc_exit(void) 254 { 255 platform_driver_unregister(&opal_rtc_driver); 256 } 257 258 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); 259 MODULE_DESCRIPTION("IBM OPAL RTC driver"); 260 MODULE_LICENSE("GPL"); 261 262 module_init(opal_rtc_init); 263 module_exit(opal_rtc_exit); 264