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 s64 rc = OPAL_BUSY; 61 int retries = 10; 62 u32 y_m_d; 63 u64 h_m_s_ms; 64 __be32 __y_m_d; 65 __be64 __h_m_s_ms; 66 67 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 68 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); 69 if (rc == OPAL_BUSY_EVENT) { 70 msleep(OPAL_BUSY_DELAY_MS); 71 opal_poll_events(NULL); 72 } else if (rc == OPAL_BUSY) { 73 msleep(OPAL_BUSY_DELAY_MS); 74 } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { 75 if (retries--) { 76 msleep(10); /* Wait 10ms before retry */ 77 rc = OPAL_BUSY; /* go around again */ 78 } 79 } 80 } 81 82 if (rc != OPAL_SUCCESS) 83 return -EIO; 84 85 y_m_d = be32_to_cpu(__y_m_d); 86 h_m_s_ms = be64_to_cpu(__h_m_s_ms); 87 opal_to_tm(y_m_d, h_m_s_ms, tm); 88 89 return 0; 90 } 91 92 static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm) 93 { 94 s64 rc = OPAL_BUSY; 95 int retries = 10; 96 u32 y_m_d = 0; 97 u64 h_m_s_ms = 0; 98 99 tm_to_opal(tm, &y_m_d, &h_m_s_ms); 100 101 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 102 rc = opal_rtc_write(y_m_d, h_m_s_ms); 103 if (rc == OPAL_BUSY_EVENT) { 104 msleep(OPAL_BUSY_DELAY_MS); 105 opal_poll_events(NULL); 106 } else if (rc == OPAL_BUSY) { 107 msleep(OPAL_BUSY_DELAY_MS); 108 } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { 109 if (retries--) { 110 msleep(10); /* Wait 10ms before retry */ 111 rc = OPAL_BUSY; /* go around again */ 112 } 113 } 114 } 115 116 return rc == OPAL_SUCCESS ? 0 : -EIO; 117 } 118 119 /* 120 * TPO Timed Power-On 121 * 122 * TPO get/set OPAL calls care about the hour and min and to make it consistent 123 * with the rtc utility time conversion functions, we use the 'u64' to store 124 * its value and perform bit shift by 32 before use.. 125 */ 126 static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 127 { 128 __be32 __y_m_d, __h_m; 129 struct opal_msg msg; 130 int rc, token; 131 u64 h_m_s_ms; 132 u32 y_m_d; 133 134 token = opal_async_get_token_interruptible(); 135 if (token < 0) { 136 if (token != -ERESTARTSYS) 137 pr_err("Failed to get the async token\n"); 138 139 return token; 140 } 141 142 rc = opal_tpo_read(token, &__y_m_d, &__h_m); 143 if (rc != OPAL_ASYNC_COMPLETION) { 144 rc = -EIO; 145 goto exit; 146 } 147 148 rc = opal_async_wait_response(token, &msg); 149 if (rc) { 150 rc = -EIO; 151 goto exit; 152 } 153 154 rc = opal_get_async_rc(msg); 155 if (rc != OPAL_SUCCESS) { 156 rc = -EIO; 157 goto exit; 158 } 159 160 y_m_d = be32_to_cpu(__y_m_d); 161 h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); 162 163 /* check if no alarm is set */ 164 if (y_m_d == 0 && h_m_s_ms == 0) { 165 pr_debug("No alarm is set\n"); 166 rc = -ENOENT; 167 goto exit; 168 } else { 169 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); 170 } 171 172 opal_to_tm(y_m_d, h_m_s_ms, &alarm->time); 173 174 exit: 175 opal_async_release_token(token); 176 return rc; 177 } 178 179 /* Set Timed Power-On */ 180 static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 181 { 182 u64 h_m_s_ms = 0; 183 struct opal_msg msg; 184 u32 y_m_d = 0; 185 int token, rc; 186 187 /* if alarm is enabled */ 188 if (alarm->enabled) { 189 tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms); 190 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); 191 192 } else { 193 pr_debug("Alarm getting disabled\n"); 194 } 195 196 token = opal_async_get_token_interruptible(); 197 if (token < 0) { 198 if (token != -ERESTARTSYS) 199 pr_err("Failed to get the async token\n"); 200 201 return token; 202 } 203 204 /* TPO, we care about hour and minute */ 205 rc = opal_tpo_write(token, y_m_d, 206 (u32)((h_m_s_ms >> 32) & 0xffff0000)); 207 if (rc != OPAL_ASYNC_COMPLETION) { 208 rc = -EIO; 209 goto exit; 210 } 211 212 rc = opal_async_wait_response(token, &msg); 213 if (rc) { 214 rc = -EIO; 215 goto exit; 216 } 217 218 rc = opal_get_async_rc(msg); 219 if (rc != OPAL_SUCCESS) 220 rc = -EIO; 221 222 exit: 223 opal_async_release_token(token); 224 return rc; 225 } 226 227 int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled) 228 { 229 struct rtc_wkalrm alarm = { .enabled = 0 }; 230 231 /* 232 * TPO is automatically enabled when opal_set_tpo_time() is called with 233 * non-zero rtc-time. We only handle disable case which needs to be 234 * explicitly told to opal. 235 */ 236 return enabled ? 0 : opal_set_tpo_time(dev, &alarm); 237 } 238 239 static struct rtc_class_ops opal_rtc_ops = { 240 .read_time = opal_get_rtc_time, 241 .set_time = opal_set_rtc_time, 242 }; 243 244 static int opal_rtc_probe(struct platform_device *pdev) 245 { 246 struct rtc_device *rtc; 247 248 if (pdev->dev.of_node && 249 (of_property_read_bool(pdev->dev.of_node, "wakeup-source") || 250 of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */)) { 251 device_set_wakeup_capable(&pdev->dev, true); 252 opal_rtc_ops.read_alarm = opal_get_tpo_time; 253 opal_rtc_ops.set_alarm = opal_set_tpo_time; 254 opal_rtc_ops.alarm_irq_enable = opal_tpo_alarm_irq_enable; 255 } 256 257 rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops, 258 THIS_MODULE); 259 if (IS_ERR(rtc)) 260 return PTR_ERR(rtc); 261 262 rtc->uie_unsupported = 1; 263 264 return 0; 265 } 266 267 static const struct of_device_id opal_rtc_match[] = { 268 { 269 .compatible = "ibm,opal-rtc", 270 }, 271 { } 272 }; 273 MODULE_DEVICE_TABLE(of, opal_rtc_match); 274 275 static const struct platform_device_id opal_rtc_driver_ids[] = { 276 { 277 .name = "opal-rtc", 278 }, 279 { } 280 }; 281 MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids); 282 283 static struct platform_driver opal_rtc_driver = { 284 .probe = opal_rtc_probe, 285 .id_table = opal_rtc_driver_ids, 286 .driver = { 287 .name = DRVNAME, 288 .of_match_table = opal_rtc_match, 289 }, 290 }; 291 292 static int __init opal_rtc_init(void) 293 { 294 if (!firmware_has_feature(FW_FEATURE_OPAL)) 295 return -ENODEV; 296 297 return platform_driver_register(&opal_rtc_driver); 298 } 299 300 static void __exit opal_rtc_exit(void) 301 { 302 platform_driver_unregister(&opal_rtc_driver); 303 } 304 305 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); 306 MODULE_DESCRIPTION("IBM OPAL RTC driver"); 307 MODULE_LICENSE("GPL"); 308 309 module_init(opal_rtc_init); 310 module_exit(opal_rtc_exit); 311