linux/drivers/rtc/rtc-tps65910.c
<<
>>
Prefs
   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
  28struct 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
  37static 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 */
  57static 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
  88static 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 */
 129static 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
 160static 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
 191static 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
 217static 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
 225static 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 */
 295static 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
 308static 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
 324static 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
 333static 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
 343static 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
 353module_platform_driver(tps65910_rtc_driver);
 354MODULE_ALIAS("platform:rtc-tps65910");
 355MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
 356MODULE_LICENSE("GPL");
 357
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.