| 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 | /* To store the list of enabled interrupts */ |
| 31 | u32 irqstat; |
| 32 | }; |
| 33 | |
| 34 | /* Total number of RTC registers needed to set time*/ |
| 35 | #define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1) |
| 36 | |
| 37 | static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled) |
| 38 | { |
| 39 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 40 | u8 val = 0; |
| 41 | |
| 42 | if (enabled) |
| 43 | val = TPS65910_RTC_INTERRUPTS_IT_ALARM; |
| 44 | |
| 45 | return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val); |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * Gets current tps65910 RTC time and date parameters. |
| 50 | * |
| 51 | * The RTC's time/alarm representation is not what gmtime(3) requires |
| 52 | * Linux to use: |
| 53 | * |
| 54 | * - Months are 1..12 vs Linux 0-11 |
| 55 | * - Years are 0..99 vs Linux 1900..N (we assume 21st century) |
| 56 | */ |
| 57 | static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| 58 | { |
| 59 | unsigned char rtc_data[NUM_TIME_REGS]; |
| 60 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 61 | int ret; |
| 62 | |
| 63 | /* Copy RTC counting registers to static registers or latches */ |
| 64 | ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, |
| 65 | TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME); |
| 66 | if (ret < 0) { |
| 67 | dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret); |
| 68 | return ret; |
| 69 | } |
| 70 | |
| 71 | ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data, |
| 72 | NUM_TIME_REGS); |
| 73 | if (ret < 0) { |
| 74 | dev_err(dev, "reading from RTC failed with err:%d\n", ret); |
| 75 | return ret; |
| 76 | } |
| 77 | |
| 78 | tm->tm_sec = bcd2bin(rtc_data[0]); |
| 79 | tm->tm_min = bcd2bin(rtc_data[1]); |
| 80 | tm->tm_hour = bcd2bin(rtc_data[2]); |
| 81 | tm->tm_mday = bcd2bin(rtc_data[3]); |
| 82 | tm->tm_mon = bcd2bin(rtc_data[4]) - 1; |
| 83 | tm->tm_year = bcd2bin(rtc_data[5]) + 100; |
| 84 | |
| 85 | return ret; |
| 86 | } |
| 87 | |
| 88 | static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| 89 | { |
| 90 | unsigned char rtc_data[NUM_TIME_REGS]; |
| 91 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 92 | int ret; |
| 93 | |
| 94 | rtc_data[0] = bin2bcd(tm->tm_sec); |
| 95 | rtc_data[1] = bin2bcd(tm->tm_min); |
| 96 | rtc_data[2] = bin2bcd(tm->tm_hour); |
| 97 | rtc_data[3] = bin2bcd(tm->tm_mday); |
| 98 | rtc_data[4] = bin2bcd(tm->tm_mon + 1); |
| 99 | rtc_data[5] = bin2bcd(tm->tm_year - 100); |
| 100 | |
| 101 | /* Stop RTC while updating the RTC time registers */ |
| 102 | ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, |
| 103 | TPS65910_RTC_CTRL_STOP_RTC, 0); |
| 104 | if (ret < 0) { |
| 105 | dev_err(dev, "RTC stop failed with err:%d\n", ret); |
| 106 | return ret; |
| 107 | } |
| 108 | |
| 109 | /* update all the time registers in one shot */ |
| 110 | ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data, |
| 111 | NUM_TIME_REGS); |
| 112 | if (ret < 0) { |
| 113 | dev_err(dev, "rtc_set_time error %d\n", ret); |
| 114 | return ret; |
| 115 | } |
| 116 | |
| 117 | /* Start back RTC */ |
| 118 | ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL, |
| 119 | TPS65910_RTC_CTRL_STOP_RTC, 1); |
| 120 | if (ret < 0) |
| 121 | dev_err(dev, "RTC start failed with err:%d\n", ret); |
| 122 | |
| 123 | return ret; |
| 124 | } |
| 125 | |
| 126 | /* |
| 127 | * Gets current tps65910 RTC alarm time. |
| 128 | */ |
| 129 | static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| 130 | { |
| 131 | unsigned char alarm_data[NUM_TIME_REGS]; |
| 132 | u32 int_val; |
| 133 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 134 | int ret; |
| 135 | |
| 136 | ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data, |
| 137 | NUM_TIME_REGS); |
| 138 | if (ret < 0) { |
| 139 | dev_err(dev, "rtc_read_alarm error %d\n", ret); |
| 140 | return ret; |
| 141 | } |
| 142 | |
| 143 | alm->time.tm_sec = bcd2bin(alarm_data[0]); |
| 144 | alm->time.tm_min = bcd2bin(alarm_data[1]); |
| 145 | alm->time.tm_hour = bcd2bin(alarm_data[2]); |
| 146 | alm->time.tm_mday = bcd2bin(alarm_data[3]); |
| 147 | alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1; |
| 148 | alm->time.tm_year = bcd2bin(alarm_data[5]) + 100; |
| 149 | |
| 150 | ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val); |
| 151 | if (ret < 0) |
| 152 | return ret; |
| 153 | |
| 154 | if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM) |
| 155 | alm->enabled = 1; |
| 156 | |
| 157 | return ret; |
| 158 | } |
| 159 | |
| 160 | static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| 161 | { |
| 162 | unsigned char alarm_data[NUM_TIME_REGS]; |
| 163 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 164 | int ret; |
| 165 | |
| 166 | ret = tps65910_rtc_alarm_irq_enable(dev, 0); |
| 167 | if (ret) |
| 168 | return ret; |
| 169 | |
| 170 | alarm_data[0] = bin2bcd(alm->time.tm_sec); |
| 171 | alarm_data[1] = bin2bcd(alm->time.tm_min); |
| 172 | alarm_data[2] = bin2bcd(alm->time.tm_hour); |
| 173 | alarm_data[3] = bin2bcd(alm->time.tm_mday); |
| 174 | alarm_data[4] = bin2bcd(alm->time.tm_mon + 1); |
| 175 | alarm_data[5] = bin2bcd(alm->time.tm_year - 100); |
| 176 | |
| 177 | /* update all the alarm registers in one shot */ |
| 178 | ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS, |
| 179 | alarm_data, NUM_TIME_REGS); |
| 180 | if (ret) { |
| 181 | dev_err(dev, "rtc_set_alarm error %d\n", ret); |
| 182 | return ret; |
| 183 | } |
| 184 | |
| 185 | if (alm->enabled) |
| 186 | ret = tps65910_rtc_alarm_irq_enable(dev, 1); |
| 187 | |
| 188 | return ret; |
| 189 | } |
| 190 | |
| 191 | static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc) |
| 192 | { |
| 193 | struct device *dev = rtc; |
| 194 | unsigned long events = 0; |
| 195 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 196 | struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev); |
| 197 | int ret; |
| 198 | u32 rtc_reg; |
| 199 | |
| 200 | ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg); |
| 201 | if (ret) |
| 202 | return IRQ_NONE; |
| 203 | |
| 204 | if (rtc_reg & TPS65910_RTC_STATUS_ALARM) |
| 205 | events = RTC_IRQF | RTC_AF; |
| 206 | |
| 207 | ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg); |
| 208 | if (ret) |
| 209 | return IRQ_NONE; |
| 210 | |
| 211 | /* Notify RTC core on event */ |
| 212 | rtc_update_irq(tps_rtc->rtc, 1, events); |
| 213 | |
| 214 | return IRQ_HANDLED; |
| 215 | } |
| 216 | |
| 217 | static const struct rtc_class_ops tps65910_rtc_ops = { |
| 218 | .read_time = tps65910_rtc_read_time, |
| 219 | .set_time = tps65910_rtc_set_time, |
| 220 | .read_alarm = tps65910_rtc_read_alarm, |
| 221 | .set_alarm = tps65910_rtc_set_alarm, |
| 222 | .alarm_irq_enable = tps65910_rtc_alarm_irq_enable, |
| 223 | }; |
| 224 | |
| 225 | static int tps65910_rtc_probe(struct platform_device *pdev) |
| 226 | { |
| 227 | struct tps65910 *tps65910 = NULL; |
| 228 | struct tps65910_rtc *tps_rtc = NULL; |
| 229 | int ret; |
| 230 | int irq; |
| 231 | u32 rtc_reg; |
| 232 | |
| 233 | tps65910 = dev_get_drvdata(pdev->dev.parent); |
| 234 | |
| 235 | tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc), |
| 236 | GFP_KERNEL); |
| 237 | if (!tps_rtc) |
| 238 | return -ENOMEM; |
| 239 | |
| 240 | /* Clear pending interrupts */ |
| 241 | ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg); |
| 242 | if (ret < 0) |
| 243 | return ret; |
| 244 | |
| 245 | ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg); |
| 246 | if (ret < 0) |
| 247 | return ret; |
| 248 | |
| 249 | dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n"); |
| 250 | |
| 251 | /* Enable RTC digital power domain */ |
| 252 | ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL, |
| 253 | DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT); |
| 254 | if (ret < 0) |
| 255 | return ret; |
| 256 | |
| 257 | rtc_reg = TPS65910_RTC_CTRL_STOP_RTC; |
| 258 | ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg); |
| 259 | if (ret < 0) |
| 260 | return ret; |
| 261 | |
| 262 | irq = platform_get_irq(pdev, 0); |
| 263 | if (irq <= 0) { |
| 264 | dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n", |
| 265 | irq); |
| 266 | return ret; |
| 267 | } |
| 268 | |
| 269 | ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, |
| 270 | tps65910_rtc_interrupt, IRQF_TRIGGER_LOW, |
| 271 | dev_name(&pdev->dev), &pdev->dev); |
| 272 | if (ret < 0) { |
| 273 | dev_err(&pdev->dev, "IRQ is not free.\n"); |
| 274 | return ret; |
| 275 | } |
| 276 | device_init_wakeup(&pdev->dev, 1); |
| 277 | |
| 278 | tps_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev, |
| 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 | /* leave rtc running, but disable irqs */ |
| 298 | struct tps65910_rtc *tps_rtc = platform_get_drvdata(pdev); |
| 299 | |
| 300 | tps65910_rtc_alarm_irq_enable(&pdev->dev, 0); |
| 301 | |
| 302 | rtc_device_unregister(tps_rtc->rtc); |
| 303 | return 0; |
| 304 | } |
| 305 | |
| 306 | #ifdef CONFIG_PM_SLEEP |
| 307 | |
| 308 | static int tps65910_rtc_suspend(struct device *dev) |
| 309 | { |
| 310 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 311 | u8 alarm = TPS65910_RTC_INTERRUPTS_IT_ALARM; |
| 312 | int ret; |
| 313 | |
| 314 | /* Store current list of enabled interrupts*/ |
| 315 | ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, |
| 316 | &tps->rtc->irqstat); |
| 317 | if (ret < 0) |
| 318 | return ret; |
| 319 | |
| 320 | /* Enable RTC ALARM interrupt only */ |
| 321 | return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, alarm); |
| 322 | } |
| 323 | |
| 324 | static int tps65910_rtc_resume(struct device *dev) |
| 325 | { |
| 326 | struct tps65910 *tps = dev_get_drvdata(dev->parent); |
| 327 | |
| 328 | /* Restore list of enabled interrupts before suspend */ |
| 329 | return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, |
| 330 | tps->rtc->irqstat); |
| 331 | } |
| 332 | |
| 333 | static const struct dev_pm_ops tps65910_rtc_pm_ops = { |
| 334 | .suspend = tps65910_rtc_suspend, |
| 335 | .resume = tps65910_rtc_resume, |
| 336 | }; |
| 337 | |
| 338 | #define DEV_PM_OPS (&tps65910_rtc_pm_ops) |
| 339 | #else |
| 340 | #define DEV_PM_OPS NULL |
| 341 | #endif |
| 342 | |
| 343 | static struct platform_driver tps65910_rtc_driver = { |
| 344 | .probe = tps65910_rtc_probe, |
| 345 | .remove = tps65910_rtc_remove, |
| 346 | .driver = { |
| 347 | .owner = THIS_MODULE, |
| 348 | .name = "tps65910-rtc", |
| 349 | .pm = DEV_PM_OPS, |
| 350 | }, |
| 351 | }; |
| 352 | |
| 353 | module_platform_driver(tps65910_rtc_driver); |
| 354 | MODULE_ALIAS("platform:rtc-tps65910"); |
| 355 | MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>"); |
| 356 | MODULE_LICENSE("GPL"); |