1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Real Time Clock driver for Marvell 88PM860x PMIC 4 * 5 * Copyright (c) 2010 Marvell International Ltd. 6 * Author: Haojian Zhuang <haojian.zhuang@marvell.com> 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/of.h> 12 #include <linux/platform_device.h> 13 #include <linux/slab.h> 14 #include <linux/mutex.h> 15 #include <linux/rtc.h> 16 #include <linux/delay.h> 17 #include <linux/mfd/core.h> 18 #include <linux/mfd/88pm860x.h> 19 20 #define VRTC_CALIBRATION 21 22 struct pm860x_rtc_info { 23 struct pm860x_chip *chip; 24 struct i2c_client *i2c; 25 struct rtc_device *rtc_dev; 26 struct device *dev; 27 struct delayed_work calib_work; 28 29 int irq; 30 int vrtc; 31 }; 32 33 #define REG_VRTC_MEAS1 0x7D 34 35 #define REG0_ADDR 0xB0 36 #define REG1_ADDR 0xB2 37 #define REG2_ADDR 0xB4 38 #define REG3_ADDR 0xB6 39 40 #define REG0_DATA 0xB1 41 #define REG1_DATA 0xB3 42 #define REG2_DATA 0xB5 43 #define REG3_DATA 0xB7 44 45 /* bit definitions of Measurement Enable Register 2 (0x51) */ 46 #define MEAS2_VRTC (1 << 0) 47 48 /* bit definitions of RTC Register 1 (0xA0) */ 49 #define ALARM_EN (1 << 3) 50 #define ALARM_WAKEUP (1 << 4) 51 #define ALARM (1 << 5) 52 #define RTC1_USE_XO (1 << 7) 53 54 #define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */ 55 56 static irqreturn_t rtc_update_handler(int irq, void *data) 57 { 58 struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data; 59 int mask; 60 61 mask = ALARM | ALARM_WAKEUP; 62 pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask); 63 rtc_update_irq(info->rtc_dev, 1, RTC_AF); 64 return IRQ_HANDLED; 65 } 66 67 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 68 { 69 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 70 71 if (enabled) 72 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN); 73 else 74 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 75 return 0; 76 } 77 78 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm) 79 { 80 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 81 unsigned char buf[8]; 82 unsigned long ticks, base, data; 83 84 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 85 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 86 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 87 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 88 (buf[5] << 8) | buf[7]; 89 90 /* load 32-bit read-only counter */ 91 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 92 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 93 (buf[1] << 8) | buf[0]; 94 ticks = base + data; 95 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 96 base, data, ticks); 97 98 rtc_time64_to_tm(ticks, tm); 99 100 return 0; 101 } 102 103 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm) 104 { 105 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 106 unsigned char buf[4]; 107 unsigned long ticks, base, data; 108 109 if (tm->tm_year > 206) { 110 dev_dbg(info->dev, "Set time %d out of range. " 111 "Please set time between 1970 to 2106.\n", 112 1900 + tm->tm_year); 113 return -EINVAL; 114 } 115 ticks = rtc_tm_to_time64(tm); 116 117 /* load 32-bit read-only counter */ 118 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 119 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 120 (buf[1] << 8) | buf[0]; 121 base = ticks - data; 122 dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 123 base, data, ticks); 124 125 pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF); 126 pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF); 127 pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF); 128 pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF); 129 130 return 0; 131 } 132 133 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 134 { 135 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 136 unsigned char buf[8]; 137 unsigned long ticks, base, data; 138 int ret; 139 140 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 141 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 142 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 143 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 144 (buf[5] << 8) | buf[7]; 145 146 pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 147 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 148 (buf[1] << 8) | buf[0]; 149 ticks = base + data; 150 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 151 base, data, ticks); 152 153 rtc_time64_to_tm(ticks, &alrm->time); 154 ret = pm860x_reg_read(info->i2c, PM8607_RTC1); 155 alrm->enabled = (ret & ALARM_EN) ? 1 : 0; 156 alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0; 157 return 0; 158 } 159 160 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 161 { 162 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 163 unsigned long ticks, base, data; 164 unsigned char buf[8]; 165 int mask; 166 167 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 168 169 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 170 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 171 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 172 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 173 (buf[5] << 8) | buf[7]; 174 175 ticks = rtc_tm_to_time64(&alrm->time); 176 data = ticks - base; 177 178 buf[0] = data & 0xff; 179 buf[1] = (data >> 8) & 0xff; 180 buf[2] = (data >> 16) & 0xff; 181 buf[3] = (data >> 24) & 0xff; 182 pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 183 if (alrm->enabled) { 184 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 185 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask); 186 } else { 187 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 188 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, 189 ALARM | ALARM_WAKEUP); 190 } 191 return 0; 192 } 193 194 static const struct rtc_class_ops pm860x_rtc_ops = { 195 .read_time = pm860x_rtc_read_time, 196 .set_time = pm860x_rtc_set_time, 197 .read_alarm = pm860x_rtc_read_alarm, 198 .set_alarm = pm860x_rtc_set_alarm, 199 .alarm_irq_enable = pm860x_rtc_alarm_irq_enable, 200 }; 201 202 #ifdef VRTC_CALIBRATION 203 static void calibrate_vrtc_work(struct work_struct *work) 204 { 205 struct pm860x_rtc_info *info = container_of(work, 206 struct pm860x_rtc_info, calib_work.work); 207 unsigned char buf[2]; 208 unsigned int sum, data, mean, vrtc_set; 209 int i; 210 211 for (i = 0, sum = 0; i < 16; i++) { 212 msleep(100); 213 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf); 214 data = (buf[0] << 4) | buf[1]; 215 data = (data * 5400) >> 12; /* convert to mv */ 216 sum += data; 217 } 218 mean = sum >> 4; 219 vrtc_set = 2700 + (info->vrtc & 0x3) * 200; 220 dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set); 221 222 sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1); 223 data = sum & 0x3; 224 if ((mean + 200) < vrtc_set) { 225 /* try higher voltage */ 226 if (++data == 4) 227 goto out; 228 data = (sum & 0xf8) | (data & 0x3); 229 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 230 } else if ((mean - 200) > vrtc_set) { 231 /* try lower voltage */ 232 if (data-- == 0) 233 goto out; 234 data = (sum & 0xf8) | (data & 0x3); 235 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 236 } else 237 goto out; 238 dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data); 239 /* trigger next calibration since VRTC is updated */ 240 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 241 return; 242 out: 243 /* disable measurement */ 244 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 245 dev_dbg(info->dev, "finish VRTC calibration\n"); 246 return; 247 } 248 #endif 249 250 #ifdef CONFIG_OF 251 static int pm860x_rtc_dt_init(struct platform_device *pdev, 252 struct pm860x_rtc_info *info) 253 { 254 struct device_node *np = pdev->dev.parent->of_node; 255 int ret; 256 if (!np) 257 return -ENODEV; 258 np = of_get_child_by_name(np, "rtc"); 259 if (!np) { 260 dev_err(&pdev->dev, "failed to find rtc node\n"); 261 return -ENODEV; 262 } 263 ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc); 264 if (ret) 265 info->vrtc = 0; 266 of_node_put(np); 267 return 0; 268 } 269 #else 270 #define pm860x_rtc_dt_init(x, y) do { } while (0) 271 #endif 272 273 static int pm860x_rtc_probe(struct platform_device *pdev) 274 { 275 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 276 struct pm860x_rtc_info *info; 277 int ret; 278 279 info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info), 280 GFP_KERNEL); 281 if (!info) 282 return -ENOMEM; 283 info->irq = platform_get_irq(pdev, 0); 284 if (info->irq < 0) 285 return info->irq; 286 287 info->chip = chip; 288 info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion; 289 info->dev = &pdev->dev; 290 dev_set_drvdata(&pdev->dev, info); 291 292 info->rtc_dev = devm_rtc_allocate_device(&pdev->dev); 293 if (IS_ERR(info->rtc_dev)) 294 return PTR_ERR(info->rtc_dev); 295 296 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 297 rtc_update_handler, IRQF_ONESHOT, "rtc", 298 info); 299 if (ret < 0) { 300 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", 301 info->irq, ret); 302 return ret; 303 } 304 305 /* set addresses of 32-bit base value for RTC time */ 306 pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA); 307 pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA); 308 pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA); 309 pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA); 310 311 pm860x_rtc_dt_init(pdev, info); 312 313 info->rtc_dev->ops = &pm860x_rtc_ops; 314 info->rtc_dev->range_max = U32_MAX; 315 316 ret = rtc_register_device(info->rtc_dev); 317 if (ret) 318 return ret; 319 320 /* 321 * enable internal XO instead of internal 3.25MHz clock since it can 322 * free running in PMIC power-down state. 323 */ 324 pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO); 325 326 #ifdef VRTC_CALIBRATION 327 /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */ 328 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC); 329 330 /* calibrate VRTC */ 331 INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work); 332 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 333 #endif /* VRTC_CALIBRATION */ 334 335 device_init_wakeup(&pdev->dev, 1); 336 337 return 0; 338 } 339 340 static int pm860x_rtc_remove(struct platform_device *pdev) 341 { 342 struct pm860x_rtc_info *info = platform_get_drvdata(pdev); 343 344 #ifdef VRTC_CALIBRATION 345 cancel_delayed_work_sync(&info->calib_work); 346 /* disable measurement */ 347 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 348 #endif /* VRTC_CALIBRATION */ 349 350 return 0; 351 } 352 353 #ifdef CONFIG_PM_SLEEP 354 static int pm860x_rtc_suspend(struct device *dev) 355 { 356 struct platform_device *pdev = to_platform_device(dev); 357 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 358 359 if (device_may_wakeup(dev)) 360 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC; 361 return 0; 362 } 363 static int pm860x_rtc_resume(struct device *dev) 364 { 365 struct platform_device *pdev = to_platform_device(dev); 366 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 367 368 if (device_may_wakeup(dev)) 369 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC); 370 return 0; 371 } 372 #endif 373 374 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume); 375 376 static struct platform_driver pm860x_rtc_driver = { 377 .driver = { 378 .name = "88pm860x-rtc", 379 .pm = &pm860x_rtc_pm_ops, 380 }, 381 .probe = pm860x_rtc_probe, 382 .remove = pm860x_rtc_remove, 383 }; 384 385 module_platform_driver(pm860x_rtc_driver); 386 387 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver"); 388 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 389 MODULE_LICENSE("GPL"); 390