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 ticks = rtc_tm_to_time64(tm); 110 111 /* load 32-bit read-only counter */ 112 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 113 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 114 (buf[1] << 8) | buf[0]; 115 base = ticks - data; 116 dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 117 base, data, ticks); 118 119 pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF); 120 pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF); 121 pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF); 122 pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF); 123 124 return 0; 125 } 126 127 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 128 { 129 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 130 unsigned char buf[8]; 131 unsigned long ticks, base, data; 132 int ret; 133 134 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 135 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 136 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 137 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 138 (buf[5] << 8) | buf[7]; 139 140 pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 141 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 142 (buf[1] << 8) | buf[0]; 143 ticks = base + data; 144 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 145 base, data, ticks); 146 147 rtc_time64_to_tm(ticks, &alrm->time); 148 ret = pm860x_reg_read(info->i2c, PM8607_RTC1); 149 alrm->enabled = (ret & ALARM_EN) ? 1 : 0; 150 alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0; 151 return 0; 152 } 153 154 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 155 { 156 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 157 unsigned long ticks, base, data; 158 unsigned char buf[8]; 159 int mask; 160 161 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 162 163 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 164 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 165 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 166 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 167 (buf[5] << 8) | buf[7]; 168 169 ticks = rtc_tm_to_time64(&alrm->time); 170 data = ticks - base; 171 172 buf[0] = data & 0xff; 173 buf[1] = (data >> 8) & 0xff; 174 buf[2] = (data >> 16) & 0xff; 175 buf[3] = (data >> 24) & 0xff; 176 pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 177 if (alrm->enabled) { 178 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 179 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask); 180 } else { 181 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 182 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, 183 ALARM | ALARM_WAKEUP); 184 } 185 return 0; 186 } 187 188 static const struct rtc_class_ops pm860x_rtc_ops = { 189 .read_time = pm860x_rtc_read_time, 190 .set_time = pm860x_rtc_set_time, 191 .read_alarm = pm860x_rtc_read_alarm, 192 .set_alarm = pm860x_rtc_set_alarm, 193 .alarm_irq_enable = pm860x_rtc_alarm_irq_enable, 194 }; 195 196 #ifdef VRTC_CALIBRATION 197 static void calibrate_vrtc_work(struct work_struct *work) 198 { 199 struct pm860x_rtc_info *info = container_of(work, 200 struct pm860x_rtc_info, calib_work.work); 201 unsigned char buf[2]; 202 unsigned int sum, data, mean, vrtc_set; 203 int i; 204 205 for (i = 0, sum = 0; i < 16; i++) { 206 msleep(100); 207 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf); 208 data = (buf[0] << 4) | buf[1]; 209 data = (data * 5400) >> 12; /* convert to mv */ 210 sum += data; 211 } 212 mean = sum >> 4; 213 vrtc_set = 2700 + (info->vrtc & 0x3) * 200; 214 dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set); 215 216 sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1); 217 data = sum & 0x3; 218 if ((mean + 200) < vrtc_set) { 219 /* try higher voltage */ 220 if (++data == 4) 221 goto out; 222 data = (sum & 0xf8) | (data & 0x3); 223 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 224 } else if ((mean - 200) > vrtc_set) { 225 /* try lower voltage */ 226 if (data-- == 0) 227 goto out; 228 data = (sum & 0xf8) | (data & 0x3); 229 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 230 } else 231 goto out; 232 dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data); 233 /* trigger next calibration since VRTC is updated */ 234 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 235 return; 236 out: 237 /* disable measurement */ 238 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 239 dev_dbg(info->dev, "finish VRTC calibration\n"); 240 return; 241 } 242 #endif 243 244 #ifdef CONFIG_OF 245 static int pm860x_rtc_dt_init(struct platform_device *pdev, 246 struct pm860x_rtc_info *info) 247 { 248 struct device_node *np = pdev->dev.parent->of_node; 249 int ret; 250 if (!np) 251 return -ENODEV; 252 np = of_get_child_by_name(np, "rtc"); 253 if (!np) { 254 dev_err(&pdev->dev, "failed to find rtc node\n"); 255 return -ENODEV; 256 } 257 ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc); 258 if (ret) 259 info->vrtc = 0; 260 of_node_put(np); 261 return 0; 262 } 263 #else 264 #define pm860x_rtc_dt_init(x, y) do { } while (0) 265 #endif 266 267 static int pm860x_rtc_probe(struct platform_device *pdev) 268 { 269 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 270 struct pm860x_rtc_info *info; 271 int ret; 272 273 info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info), 274 GFP_KERNEL); 275 if (!info) 276 return -ENOMEM; 277 info->irq = platform_get_irq(pdev, 0); 278 if (info->irq < 0) 279 return info->irq; 280 281 info->chip = chip; 282 info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion; 283 info->dev = &pdev->dev; 284 dev_set_drvdata(&pdev->dev, info); 285 286 info->rtc_dev = devm_rtc_allocate_device(&pdev->dev); 287 if (IS_ERR(info->rtc_dev)) 288 return PTR_ERR(info->rtc_dev); 289 290 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 291 rtc_update_handler, IRQF_ONESHOT, "rtc", 292 info); 293 if (ret < 0) { 294 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", 295 info->irq, ret); 296 return ret; 297 } 298 299 /* set addresses of 32-bit base value for RTC time */ 300 pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA); 301 pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA); 302 pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA); 303 pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA); 304 305 pm860x_rtc_dt_init(pdev, info); 306 307 info->rtc_dev->ops = &pm860x_rtc_ops; 308 info->rtc_dev->range_max = U32_MAX; 309 310 ret = devm_rtc_register_device(info->rtc_dev); 311 if (ret) 312 return ret; 313 314 /* 315 * enable internal XO instead of internal 3.25MHz clock since it can 316 * free running in PMIC power-down state. 317 */ 318 pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO); 319 320 #ifdef VRTC_CALIBRATION 321 /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */ 322 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC); 323 324 /* calibrate VRTC */ 325 INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work); 326 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 327 #endif /* VRTC_CALIBRATION */ 328 329 device_init_wakeup(&pdev->dev, 1); 330 331 return 0; 332 } 333 334 static int pm860x_rtc_remove(struct platform_device *pdev) 335 { 336 struct pm860x_rtc_info *info = platform_get_drvdata(pdev); 337 338 #ifdef VRTC_CALIBRATION 339 cancel_delayed_work_sync(&info->calib_work); 340 /* disable measurement */ 341 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 342 #endif /* VRTC_CALIBRATION */ 343 344 return 0; 345 } 346 347 #ifdef CONFIG_PM_SLEEP 348 static int pm860x_rtc_suspend(struct device *dev) 349 { 350 struct platform_device *pdev = to_platform_device(dev); 351 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 352 353 if (device_may_wakeup(dev)) 354 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC; 355 return 0; 356 } 357 static int pm860x_rtc_resume(struct device *dev) 358 { 359 struct platform_device *pdev = to_platform_device(dev); 360 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 361 362 if (device_may_wakeup(dev)) 363 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC); 364 return 0; 365 } 366 #endif 367 368 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume); 369 370 static struct platform_driver pm860x_rtc_driver = { 371 .driver = { 372 .name = "88pm860x-rtc", 373 .pm = &pm860x_rtc_pm_ops, 374 }, 375 .probe = pm860x_rtc_probe, 376 .remove = pm860x_rtc_remove, 377 }; 378 379 module_platform_driver(pm860x_rtc_driver); 380 381 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver"); 382 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 383 MODULE_LICENSE("GPL"); 384