1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IBM OPAL RTC driver 4 * Copyright (C) 2014 IBM 5 */ 6 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 9 #define DRVNAME "rtc-opal" 10 11 #include <linux/module.h> 12 #include <linux/err.h> 13 #include <linux/rtc.h> 14 #include <linux/delay.h> 15 #include <linux/bcd.h> 16 #include <linux/platform_device.h> 17 #include <linux/of.h> 18 #include <asm/opal.h> 19 #include <asm/firmware.h> 20 21 static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm) 22 { 23 tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) + 24 bcd2bin((y_m_d >> 16) & 0xff)) - 1900; 25 tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1; 26 tm->tm_mday = bcd2bin(y_m_d & 0xff); 27 tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff); 28 tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff); 29 tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff); 30 31 tm->tm_wday = -1; 32 } 33 34 static void tm_to_opal(struct rtc_time *tm, u32 *y_m_d, u64 *h_m_s_ms) 35 { 36 *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24; 37 *y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16; 38 *y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8; 39 *y_m_d |= ((u32)bin2bcd(tm->tm_mday)); 40 41 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56; 42 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48; 43 *h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40; 44 } 45 46 static int opal_get_rtc_time(struct device *dev, struct rtc_time *tm) 47 { 48 s64 rc = OPAL_BUSY; 49 int retries = 10; 50 u32 y_m_d; 51 u64 h_m_s_ms; 52 __be32 __y_m_d; 53 __be64 __h_m_s_ms; 54 55 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 56 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); 57 if (rc == OPAL_BUSY_EVENT) { 58 msleep(OPAL_BUSY_DELAY_MS); 59 opal_poll_events(NULL); 60 } else if (rc == OPAL_BUSY) { 61 msleep(OPAL_BUSY_DELAY_MS); 62 } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { 63 if (retries--) { 64 msleep(10); /* Wait 10ms before retry */ 65 rc = OPAL_BUSY; /* go around again */ 66 } 67 } 68 } 69 70 if (rc != OPAL_SUCCESS) 71 return -EIO; 72 73 y_m_d = be32_to_cpu(__y_m_d); 74 h_m_s_ms = be64_to_cpu(__h_m_s_ms); 75 opal_to_tm(y_m_d, h_m_s_ms, tm); 76 77 return 0; 78 } 79 80 static int opal_set_rtc_time(struct device *dev, struct rtc_time *tm) 81 { 82 s64 rc = OPAL_BUSY; 83 int retries = 10; 84 u32 y_m_d = 0; 85 u64 h_m_s_ms = 0; 86 87 tm_to_opal(tm, &y_m_d, &h_m_s_ms); 88 89 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 90 rc = opal_rtc_write(y_m_d, h_m_s_ms); 91 if (rc == OPAL_BUSY_EVENT) { 92 msleep(OPAL_BUSY_DELAY_MS); 93 opal_poll_events(NULL); 94 } else if (rc == OPAL_BUSY) { 95 msleep(OPAL_BUSY_DELAY_MS); 96 } else if (rc == OPAL_HARDWARE || rc == OPAL_INTERNAL_ERROR) { 97 if (retries--) { 98 msleep(10); /* Wait 10ms before retry */ 99 rc = OPAL_BUSY; /* go around again */ 100 } 101 } 102 } 103 104 return rc == OPAL_SUCCESS ? 0 : -EIO; 105 } 106 107 /* 108 * TPO Timed Power-On 109 * 110 * TPO get/set OPAL calls care about the hour and min and to make it consistent 111 * with the rtc utility time conversion functions, we use the 'u64' to store 112 * its value and perform bit shift by 32 before use.. 113 */ 114 static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 115 { 116 __be32 __y_m_d, __h_m; 117 struct opal_msg msg; 118 int rc, token; 119 u64 h_m_s_ms; 120 u32 y_m_d; 121 122 token = opal_async_get_token_interruptible(); 123 if (token < 0) { 124 if (token != -ERESTARTSYS) 125 pr_err("Failed to get the async token\n"); 126 127 return token; 128 } 129 130 rc = opal_tpo_read(token, &__y_m_d, &__h_m); 131 if (rc != OPAL_ASYNC_COMPLETION) { 132 rc = -EIO; 133 goto exit; 134 } 135 136 rc = opal_async_wait_response(token, &msg); 137 if (rc) { 138 rc = -EIO; 139 goto exit; 140 } 141 142 rc = opal_get_async_rc(msg); 143 if (rc != OPAL_SUCCESS) { 144 rc = -EIO; 145 goto exit; 146 } 147 148 y_m_d = be32_to_cpu(__y_m_d); 149 h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); 150 151 /* check if no alarm is set */ 152 if (y_m_d == 0 && h_m_s_ms == 0) { 153 pr_debug("No alarm is set\n"); 154 rc = -ENOENT; 155 goto exit; 156 } else { 157 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); 158 } 159 160 opal_to_tm(y_m_d, h_m_s_ms, &alarm->time); 161 162 exit: 163 opal_async_release_token(token); 164 return rc; 165 } 166 167 /* Set Timed Power-On */ 168 static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) 169 { 170 u64 h_m_s_ms = 0; 171 struct opal_msg msg; 172 u32 y_m_d = 0; 173 int token, rc; 174 175 /* if alarm is enabled */ 176 if (alarm->enabled) { 177 tm_to_opal(&alarm->time, &y_m_d, &h_m_s_ms); 178 pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); 179 180 } else { 181 pr_debug("Alarm getting disabled\n"); 182 } 183 184 token = opal_async_get_token_interruptible(); 185 if (token < 0) { 186 if (token != -ERESTARTSYS) 187 pr_err("Failed to get the async token\n"); 188 189 return token; 190 } 191 192 /* TPO, we care about hour and minute */ 193 rc = opal_tpo_write(token, y_m_d, 194 (u32)((h_m_s_ms >> 32) & 0xffff0000)); 195 if (rc != OPAL_ASYNC_COMPLETION) { 196 rc = -EIO; 197 goto exit; 198 } 199 200 rc = opal_async_wait_response(token, &msg); 201 if (rc) { 202 rc = -EIO; 203 goto exit; 204 } 205 206 rc = opal_get_async_rc(msg); 207 if (rc != OPAL_SUCCESS) 208 rc = -EIO; 209 210 exit: 211 opal_async_release_token(token); 212 return rc; 213 } 214 215 static int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled) 216 { 217 struct rtc_wkalrm alarm = { .enabled = 0 }; 218 219 /* 220 * TPO is automatically enabled when opal_set_tpo_time() is called with 221 * non-zero rtc-time. We only handle disable case which needs to be 222 * explicitly told to opal. 223 */ 224 return enabled ? 0 : opal_set_tpo_time(dev, &alarm); 225 } 226 227 static struct rtc_class_ops opal_rtc_ops = { 228 .read_time = opal_get_rtc_time, 229 .set_time = opal_set_rtc_time, 230 }; 231 232 static int opal_rtc_probe(struct platform_device *pdev) 233 { 234 struct rtc_device *rtc; 235 236 if (pdev->dev.of_node && 237 (of_property_read_bool(pdev->dev.of_node, "wakeup-source") || 238 of_property_read_bool(pdev->dev.of_node, "has-tpo")/* legacy */)) { 239 device_set_wakeup_capable(&pdev->dev, true); 240 opal_rtc_ops.read_alarm = opal_get_tpo_time; 241 opal_rtc_ops.set_alarm = opal_set_tpo_time; 242 opal_rtc_ops.alarm_irq_enable = opal_tpo_alarm_irq_enable; 243 } 244 245 rtc = devm_rtc_device_register(&pdev->dev, DRVNAME, &opal_rtc_ops, 246 THIS_MODULE); 247 if (IS_ERR(rtc)) 248 return PTR_ERR(rtc); 249 250 rtc->uie_unsupported = 1; 251 252 return 0; 253 } 254 255 static const struct of_device_id opal_rtc_match[] = { 256 { 257 .compatible = "ibm,opal-rtc", 258 }, 259 { } 260 }; 261 MODULE_DEVICE_TABLE(of, opal_rtc_match); 262 263 static const struct platform_device_id opal_rtc_driver_ids[] = { 264 { 265 .name = "opal-rtc", 266 }, 267 { } 268 }; 269 MODULE_DEVICE_TABLE(platform, opal_rtc_driver_ids); 270 271 static struct platform_driver opal_rtc_driver = { 272 .probe = opal_rtc_probe, 273 .id_table = opal_rtc_driver_ids, 274 .driver = { 275 .name = DRVNAME, 276 .of_match_table = opal_rtc_match, 277 }, 278 }; 279 280 static int __init opal_rtc_init(void) 281 { 282 if (!firmware_has_feature(FW_FEATURE_OPAL)) 283 return -ENODEV; 284 285 return platform_driver_register(&opal_rtc_driver); 286 } 287 288 static void __exit opal_rtc_exit(void) 289 { 290 platform_driver_unregister(&opal_rtc_driver); 291 } 292 293 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); 294 MODULE_DESCRIPTION("IBM OPAL RTC driver"); 295 MODULE_LICENSE("GPL"); 296 297 module_init(opal_rtc_init); 298 module_exit(opal_rtc_exit); 299