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 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 opal_poll_events(NULL); 71 else if (retries-- && (rc == OPAL_HARDWARE 72 || rc == OPAL_INTERNAL_ERROR)) 73 msleep(10); 74 else if (rc != OPAL_BUSY && rc != OPAL_BUSY_EVENT) 75 break; 76 } 77 78 if (rc != OPAL_SUCCESS) 79 return -EIO; 80 81 y_m_d = be32_to_cpu(__y_m_d); 82 h_m_s_ms = be64_to_cpu(__h_m_s_ms); 83 opal_to_tm(y_m_d, h_m_s_ms, tm); 84 85 return 0; 86 } 87 88 static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm) 89 { 90 long rc = OPAL_BUSY; 91 int retries = 10; 92 u32 y_m_d = 0; 93 u64 h_m_s_ms = 0; 94 95 tm_to_opal(tm, &y_m_d, &h_m_s_ms); 96 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 97 rc = opal_rtc_write(y_m_d, h_m_s_ms); 98 if (rc == OPAL_BUSY_EVENT) 99 opal_poll_events(NULL); 100 else if (retries-- && (rc == OPAL_HARDWARE 101 || rc == OPAL_INTERNAL_ERROR)) 102 msleep(10); 103 else if (rc != OPAL_BUSY && rc != OPAL_BUSY_EVENT) 104 break; 105 } 106 107 return rc == OPAL_SUCCESS ? 0 : -EIO; 108 } 109 110 /* 111 * TPO Timed Power-On 112 * 113 * TPO get/set OPAL calls care about the hour and min and to make it consistent 114 * with the rtc utility time conversion functions, we use the 'u64' to store 115 * its value and perform bit shift by 32 before use.. 116 */ 117 static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 118 { 119 __be32 __y_m_d, __h_m; 120 struct opal_msg msg; 121 int rc, token; 122 u64 h_m_s_ms; 123 u32 y_m_d; 124 125 token = opal_async_get_token_interruptible(); 126 if (token < 0) { 127 if (token != -ERESTARTSYS) 128 pr_err("Failed to get the async token\n"); 129 130 return token; 131 } 132 133 rc = opal_tpo_read(token, &__y_m_d, &__h_m); 134 if (rc != OPAL_ASYNC_COMPLETION) { 135 rc = -EIO; 136 goto exit; 137 } 138 139 rc = opal_async_wait_response(token, &msg); 140 if (rc) { 141 rc = -EIO; 142 goto exit; 143 } 144 145 rc = opal_get_async_rc(msg); 146 if (rc != OPAL_SUCCESS) { 147 rc = -EIO; 148 goto exit; 149 } 150 151 y_m_d = be32_to_cpu(__y_m_d); 152 h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); 153 154 /* check if no alarm is set */ 155 if (y_m_d == 0 && h_m_s_ms == 0) { 156 pr_debug("No alarm is set\n"); 157 rc = -ENOENT; 158 goto exit; 159 } else { 160 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); 161 } 162 163 opal_to_tm(y_m_d, h_m_s_ms, &alarm->time); 164 165 exit: 166 opal_async_release_token(token); 167 return rc; 168 } 169 170 /* Set Timed Power-On */ 171 static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 172 { 173 u64 h_m_s_ms = 0; 174 struct opal_msg msg; 175 u32 y_m_d = 0; 176 int token, rc; 177 178 /* if alarm is enabled */ 179 if (alarm->enabled) { 180 tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms); 181 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); 182 183 } else { 184 pr_debug("Alarm getting disabled\n"); 185 } 186 187 token = opal_async_get_token_interruptible(); 188 if (token < 0) { 189 if (token != -ERESTARTSYS) 190 pr_err("Failed to get the async token\n"); 191 192 return token; 193 } 194 195 /* TPO, we care about hour and minute */ 196 rc = opal_tpo_write(token, y_m_d, 197 (u32)((h_m_s_ms >> 32) & 0xffff0000)); 198 if (rc != OPAL_ASYNC_COMPLETION) { 199 rc = -EIO; 200 goto exit; 201 } 202 203 rc = opal_async_wait_response(token, &msg); 204 if (rc) { 205 rc = -EIO; 206 goto exit; 207 } 208 209 rc = opal_get_async_rc(msg); 210 if (rc != OPAL_SUCCESS) 211 rc = -EIO; 212 213 exit: 214 opal_async_release_token(token); 215 return rc; 216 } 217 218 int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled) 219 { 220 struct rtc_wkalrm alarm = { .enabled = 0 }; 221 222 /* 223 * TPO is automatically enabled when opal_set_tpo_time() is called with 224 * non-zero rtc-time. We only handle disable case which needs to be 225 * explicitly told to opal. 226 */ 227 return enabled ? 0 : opal_set_tpo_time(dev, &alarm); 228 } 229 230 static struct rtc_class_ops opal_rtc_ops = { 231 .read_time = opal_get_rtc_time, 232 .set_time = opal_set_rtc_time, 233 }; 234 235 static int opal_rtc_probe(struct platform_device *pdev) 236 { 237 struct rtc_device *rtc; 238 239 if (pdev->dev.of_node && 240 (of_property_read_bool(pdev->dev.of_node, "wakeup-source") || 241 of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */)) { 242 device_set_wakeup_capable(&pdev->dev, true); 243 opal_rtc_ops.read_alarm = opal_get_tpo_time; 244 opal_rtc_ops.set_alarm = opal_set_tpo_time; 245 opal_rtc_ops.alarm_irq_enable = opal_tpo_alarm_irq_enable; 246 } 247 248 rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops, 249 THIS_MODULE); 250 if (IS_ERR(rtc)) 251 return PTR_ERR(rtc); 252 253 rtc->uie_unsupported = 1; 254 255 return 0; 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