1 /* 2 * rtc-tps65910.c -- TPS65910 Real Time Clock interface 3 * 4 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. 5 * Author: Venu Byravarasu <vbyravarasu@nvidia.com> 6 * 7 * Based on original TI driver rtc-twl.c 8 * Copyright (C) 2007 MontaVista Software, Inc 9 * Author: Alexandre Rusev <source@mvista.com> 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 */ 16 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/init.h> 20 #include <linux/module.h> 21 #include <linux/types.h> 22 #include <linux/rtc.h> 23 #include <linux/bcd.h> 24 #include <linux/platform_device.h> 25 #include <linux/interrupt.h> 26 #include <linux/mfd/tps65910.h> 27 28 struct tps65910_rtc { 29 struct rtc_device *rtc; 30 int irq; 31 }; 32 33 /* Total number of RTC registers needed to set time*/ 34 #define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1) 35 36 static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) 37 { 38 struct tps65910 *tps = dev_get_drvdata(dev->parent); 39 u8 val = 0; 40 41 if (enabled) 42 val = TPS65910_RTC_INTERRUPTS_IT_ALARM; 43 44 return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val); 45 } 46 47 /* 48 * Gets current tps65910 RTC time and date parameters. 49 * 50 * The RTC's time/alarm representation is not what gmtime(3) requires 51 * Linux to use: 52 * 53 * - Months are 1..12 vs Linux 0-11 54 * - Years are 0..99 vs Linux 1900..N (we assume 21st century) 55 */ 56 static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm) 57 { 58 unsigned char rtc_data[NUM_TIME_REGS]; 59 struct tps65910 *tps = dev_get_drvdata(dev->parent); 60 int ret; 61 62 /* Copy RTC counting registers to static registers or latches */ 63 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, 64 TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME); 65 if (ret < 0) { 66 dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret); 67 return ret; 68 } 69 70 ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data, 71 NUM_TIME_REGS); 72 if (ret < 0) { 73 dev_err(dev, "reading from RTC failed with err:%d\n", ret); 74 return ret; 75 } 76 77 tm->tm_sec = bcd2bin(rtc_data[0]); 78 tm->tm_min = bcd2bin(rtc_data[1]); 79 tm->tm_hour = bcd2bin(rtc_data[2]); 80 tm->tm_mday = bcd2bin(rtc_data[3]); 81 tm->tm_mon = bcd2bin(rtc_data[4]) - 1; 82 tm->tm_year = bcd2bin(rtc_data[5]) + 100; 83 84 return ret; 85 } 86 87 static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm) 88 { 89 unsigned char rtc_data[NUM_TIME_REGS]; 90 struct tps65910 *tps = dev_get_drvdata(dev->parent); 91 int ret; 92 93 rtc_data[0] = bin2bcd(tm->tm_sec); 94 rtc_data[1] = bin2bcd(tm->tm_min); 95 rtc_data[2] = bin2bcd(tm->tm_hour); 96 rtc_data[3] = bin2bcd(tm->tm_mday); 97 rtc_data[4] = bin2bcd(tm->tm_mon + 1); 98 rtc_data[5] = bin2bcd(tm->tm_year - 100); 99 100 /* Stop RTC while updating the RTC time registers */ 101 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, 102 TPS65910_RTC_CTRL_STOP_RTC, 0); 103 if (ret < 0) { 104 dev_err(dev, "RTC stop failed with err:%d\n", ret); 105 return ret; 106 } 107 108 /* update all the time registers in one shot */ 109 ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data, 110 NUM_TIME_REGS); 111 if (ret < 0) { 112 dev_err(dev, "rtc_set_time error %d\n", ret); 113 return ret; 114 } 115 116 /* Start back RTC */ 117 ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, 118 TPS65910_RTC_CTRL_STOP_RTC, 1); 119 if (ret < 0) 120 dev_err(dev, "RTC start failed with err:%d\n", ret); 121 122 return ret; 123 } 124 125 /* 126 * Gets current tps65910 RTC alarm time. 127 */ 128 static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) 129 { 130 unsigned char alarm_data[NUM_TIME_REGS]; 131 u32 int_val; 132 struct tps65910 *tps = dev_get_drvdata(dev->parent); 133 int ret; 134 135 ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data, 136 NUM_TIME_REGS); 137 if (ret < 0) { 138 dev_err(dev, "rtc_read_alarm error %d\n", ret); 139 return ret; 140 } 141 142 alm->time.tm_sec = bcd2bin(alarm_data[0]); 143 alm->time.tm_min = bcd2bin(alarm_data[1]); 144 alm->time.tm_hour = bcd2bin(alarm_data[2]); 145 alm->time.tm_mday = bcd2bin(alarm_data[3]); 146 alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; 147 alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; 148 149 ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val); 150 if (ret < 0) 151 return ret; 152 153 if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM) 154 alm->enabled = 1; 155 156 return ret; 157 } 158 159 static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) 160 { 161 unsigned char alarm_data[NUM_TIME_REGS]; 162 struct tps65910 *tps = dev_get_drvdata(dev->parent); 163 int ret; 164 165 ret = tps65910_rtc_alarm_irq_enable(dev, 0); 166 if (ret) 167 return ret; 168 169 alarm_data[0] = bin2bcd(alm->time.tm_sec); 170 alarm_data[1] = bin2bcd(alm->time.tm_min); 171 alarm_data[2] = bin2bcd(alm->time.tm_hour); 172 alarm_data[3] = bin2bcd(alm->time.tm_mday); 173 alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); 174 alarm_data[5] = bin2bcd(alm->time.tm_year - 100); 175 176 /* update all the alarm registers in one shot */ 177 ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS, 178 alarm_data, NUM_TIME_REGS); 179 if (ret) { 180 dev_err(dev, "rtc_set_alarm error %d\n", ret); 181 return ret; 182 } 183 184 if (alm->enabled) 185 ret = tps65910_rtc_alarm_irq_enable(dev, 1); 186 187 return ret; 188 } 189 190 static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc) 191 { 192 struct device *dev = rtc; 193 unsigned long events = 0; 194 struct tps65910 *tps = dev_get_drvdata(dev->parent); 195 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); 196 int ret; 197 u32 rtc_reg; 198 199 ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg); 200 if (ret) 201 return IRQ_NONE; 202 203 if (rtc_reg & TPS65910_RTC_STATUS_ALARM) 204 events = RTC_IRQF | RTC_AF; 205 206 ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg); 207 if (ret) 208 return IRQ_NONE; 209 210 /* Notify RTC core on event */ 211 rtc_update_irq(tps_rtc->rtc, 1, events); 212 213 return IRQ_HANDLED; 214 } 215 216 static const struct rtc_class_ops tps65910_rtc_ops = { 217 .read_time = tps65910_rtc_read_time, 218 .set_time = tps65910_rtc_set_time, 219 .read_alarm = tps65910_rtc_read_alarm, 220 .set_alarm = tps65910_rtc_set_alarm, 221 .alarm_irq_enable = tps65910_rtc_alarm_irq_enable, 222 }; 223 224 static int tps65910_rtc_probe(struct platform_device *pdev) 225 { 226 struct tps65910 *tps65910 = NULL; 227 struct tps65910_rtc *tps_rtc = NULL; 228 int ret; 229 int irq; 230 u32 rtc_reg; 231 232 tps65910 = dev_get_drvdata(pdev->dev.parent); 233 234 tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc), 235 GFP_KERNEL); 236 if (!tps_rtc) 237 return -ENOMEM; 238 239 /* Clear pending interrupts */ 240 ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg); 241 if (ret < 0) 242 return ret; 243 244 ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg); 245 if (ret < 0) 246 return ret; 247 248 dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n"); 249 250 /* Enable RTC digital power domain */ 251 ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL, 252 DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT); 253 if (ret < 0) 254 return ret; 255 256 rtc_reg = TPS65910_RTC_CTRL_STOP_RTC; 257 ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg); 258 if (ret < 0) 259 return ret; 260 261 irq = platform_get_irq(pdev, 0); 262 if (irq <= 0) { 263 dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n", 264 irq); 265 return -ENXIO; 266 } 267 268 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, 269 tps65910_rtc_interrupt, IRQF_TRIGGER_LOW | IRQF_EARLY_RESUME, 270 dev_name(&pdev->dev), &pdev->dev); 271 if (ret < 0) { 272 dev_err(&pdev->dev, "IRQ is not free.\n"); 273 return ret; 274 } 275 tps_rtc->irq = irq; 276 device_set_wakeup_capable(&pdev->dev, 1); 277 278 tps_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, 279 &tps65910_rtc_ops, THIS_MODULE); 280 if (IS_ERR(tps_rtc->rtc)) { 281 ret = PTR_ERR(tps_rtc->rtc); 282 dev_err(&pdev->dev, "RTC device register: err %d\n", ret); 283 return ret; 284 } 285 286 platform_set_drvdata(pdev, tps_rtc); 287 288 return 0; 289 } 290 291 /* 292 * Disable tps65910 RTC interrupts. 293 * Sets status flag to free. 294 */ 295 static int tps65910_rtc_remove(struct platform_device *pdev) 296 { 297 tps65910_rtc_alarm_irq_enable(&pdev->dev, 0); 298 299 return 0; 300 } 301 302 #ifdef CONFIG_PM_SLEEP 303 static int tps65910_rtc_suspend(struct device *dev) 304 { 305 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); 306 307 if (device_may_wakeup(dev)) 308 enable_irq_wake(tps_rtc->irq); 309 return 0; 310 } 311 312 static int tps65910_rtc_resume(struct device *dev) 313 { 314 struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); 315 316 if (device_may_wakeup(dev)) 317 disable_irq_wake(tps_rtc->irq); 318 return 0; 319 } 320 #endif 321 322 static SIMPLE_DEV_PM_OPS(tps65910_rtc_pm_ops, tps65910_rtc_suspend, 323 tps65910_rtc_resume); 324 325 static struct platform_driver tps65910_rtc_driver = { 326 .probe = tps65910_rtc_probe, 327 .remove = tps65910_rtc_remove, 328 .driver = { 329 .owner = THIS_MODULE, 330 .name = "tps65910-rtc", 331 .pm = &tps65910_rtc_pm_ops, 332 }, 333 }; 334 335 module_platform_driver(tps65910_rtc_driver); 336 MODULE_ALIAS("platform:rtc-tps65910"); 337 MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>"); 338 MODULE_LICENSE("GPL"); 339