linux/drivers/rtc/rtc-palmas.c
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   1/*
   2 * rtc-palmas.c -- Palmas Real Time Clock driver.
   3
   4 * RTC driver for TI Palma series devices like TPS65913,
   5 * TPS65914 power management IC.
   6 *
   7 * Copyright (c) 2012, NVIDIA Corporation.
   8 *
   9 * Author: Laxman Dewangan <ldewangan@nvidia.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 as
  13 * published by the Free Software Foundation version 2.
  14 *
  15 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  16 * whether express or implied; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 * General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  23 * 02111-1307, USA
  24 */
  25
  26#include <linux/bcd.h>
  27#include <linux/errno.h>
  28#include <linux/init.h>
  29#include <linux/interrupt.h>
  30#include <linux/kernel.h>
  31#include <linux/mfd/palmas.h>
  32#include <linux/module.h>
  33#include <linux/rtc.h>
  34#include <linux/types.h>
  35#include <linux/platform_device.h>
  36#include <linux/pm.h>
  37
  38struct palmas_rtc {
  39        struct rtc_device       *rtc;
  40        struct device           *dev;
  41        unsigned int            irq;
  42};
  43
  44/* Total number of RTC registers needed to set time*/
  45#define PALMAS_NUM_TIME_REGS    (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
  46
  47static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
  48{
  49        unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
  50        struct palmas *palmas = dev_get_drvdata(dev->parent);
  51        int ret;
  52
  53        /* Copy RTC counting registers to static registers or latches */
  54        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
  55                PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
  56        if (ret < 0) {
  57                dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
  58                return ret;
  59        }
  60
  61        ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
  62                        rtc_data, PALMAS_NUM_TIME_REGS);
  63        if (ret < 0) {
  64                dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", ret);
  65                return ret;
  66        }
  67
  68        tm->tm_sec = bcd2bin(rtc_data[0]);
  69        tm->tm_min = bcd2bin(rtc_data[1]);
  70        tm->tm_hour = bcd2bin(rtc_data[2]);
  71        tm->tm_mday = bcd2bin(rtc_data[3]);
  72        tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
  73        tm->tm_year = bcd2bin(rtc_data[5]) + 100;
  74
  75        return ret;
  76}
  77
  78static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
  79{
  80        unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
  81        struct palmas *palmas = dev_get_drvdata(dev->parent);
  82        int ret;
  83
  84        rtc_data[0] = bin2bcd(tm->tm_sec);
  85        rtc_data[1] = bin2bcd(tm->tm_min);
  86        rtc_data[2] = bin2bcd(tm->tm_hour);
  87        rtc_data[3] = bin2bcd(tm->tm_mday);
  88        rtc_data[4] = bin2bcd(tm->tm_mon + 1);
  89        rtc_data[5] = bin2bcd(tm->tm_year - 100);
  90
  91        /* Stop RTC while updating the RTC time registers */
  92        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
  93                PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
  94        if (ret < 0) {
  95                dev_err(dev, "RTC stop failed, err = %d\n", ret);
  96                return ret;
  97        }
  98
  99        ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
 100                rtc_data, PALMAS_NUM_TIME_REGS);
 101        if (ret < 0) {
 102                dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
 103                return ret;
 104        }
 105
 106        /* Start back RTC */
 107        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
 108                PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
 109        if (ret < 0)
 110                dev_err(dev, "RTC start failed, err = %d\n", ret);
 111        return ret;
 112}
 113
 114static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
 115{
 116        struct palmas *palmas = dev_get_drvdata(dev->parent);
 117        u8 val;
 118
 119        val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
 120        return palmas_write(palmas, PALMAS_RTC_BASE,
 121                PALMAS_RTC_INTERRUPTS_REG, val);
 122}
 123
 124static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 125{
 126        unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
 127        u32 int_val;
 128        struct palmas *palmas = dev_get_drvdata(dev->parent);
 129        int ret;
 130
 131        ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
 132                        PALMAS_ALARM_SECONDS_REG,
 133                        alarm_data, PALMAS_NUM_TIME_REGS);
 134        if (ret < 0) {
 135                dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret);
 136                return ret;
 137        }
 138
 139        alm->time.tm_sec = bcd2bin(alarm_data[0]);
 140        alm->time.tm_min = bcd2bin(alarm_data[1]);
 141        alm->time.tm_hour = bcd2bin(alarm_data[2]);
 142        alm->time.tm_mday = bcd2bin(alarm_data[3]);
 143        alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
 144        alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
 145
 146        ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
 147                        &int_val);
 148        if (ret < 0) {
 149                dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
 150                return ret;
 151        }
 152
 153        if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
 154                alm->enabled = 1;
 155        return ret;
 156}
 157
 158static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 159{
 160        unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
 161        struct palmas *palmas = dev_get_drvdata(dev->parent);
 162        int ret;
 163
 164        ret = palmas_rtc_alarm_irq_enable(dev, 0);
 165        if (ret < 0) {
 166                dev_err(dev, "Disable RTC alarm failed\n");
 167                return ret;
 168        }
 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        ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
 178                PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
 179        if (ret < 0) {
 180                dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
 181                return ret;
 182        }
 183
 184        if (alm->enabled)
 185                ret = palmas_rtc_alarm_irq_enable(dev, 1);
 186        return ret;
 187}
 188
 189static int palmas_clear_interrupts(struct device *dev)
 190{
 191        struct palmas *palmas = dev_get_drvdata(dev->parent);
 192        unsigned int rtc_reg;
 193        int ret;
 194
 195        ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
 196                                &rtc_reg);
 197        if (ret < 0) {
 198                dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
 199                return ret;
 200        }
 201
 202        ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
 203                        rtc_reg);
 204        if (ret < 0) {
 205                dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
 206                return ret;
 207        }
 208        return 0;
 209}
 210
 211static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
 212{
 213        struct palmas_rtc *palmas_rtc = context;
 214        struct device *dev = palmas_rtc->dev;
 215        int ret;
 216
 217        ret = palmas_clear_interrupts(dev);
 218        if (ret < 0) {
 219                dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
 220                return IRQ_NONE;
 221        }
 222
 223        rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
 224        return IRQ_HANDLED;
 225}
 226
 227static struct rtc_class_ops palmas_rtc_ops = {
 228        .read_time      = palmas_rtc_read_time,
 229        .set_time       = palmas_rtc_set_time,
 230        .read_alarm     = palmas_rtc_read_alarm,
 231        .set_alarm      = palmas_rtc_set_alarm,
 232        .alarm_irq_enable = palmas_rtc_alarm_irq_enable,
 233};
 234
 235static int palmas_rtc_probe(struct platform_device *pdev)
 236{
 237        struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
 238        struct palmas_rtc *palmas_rtc = NULL;
 239        int ret;
 240
 241        palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
 242                        GFP_KERNEL);
 243        if (!palmas_rtc)
 244                return -ENOMEM;
 245
 246        /* Clear pending interrupts */
 247        ret = palmas_clear_interrupts(&pdev->dev);
 248        if (ret < 0) {
 249                dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
 250                return ret;
 251        }
 252
 253        palmas_rtc->dev = &pdev->dev;
 254        platform_set_drvdata(pdev, palmas_rtc);
 255
 256        /* Start RTC */
 257        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
 258                        PALMAS_RTC_CTRL_REG_STOP_RTC,
 259                        PALMAS_RTC_CTRL_REG_STOP_RTC);
 260        if (ret < 0) {
 261                dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
 262                return ret;
 263        }
 264
 265        palmas_rtc->irq = platform_get_irq(pdev, 0);
 266
 267        palmas_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
 268                                &palmas_rtc_ops, THIS_MODULE);
 269        if (IS_ERR(palmas_rtc->rtc)) {
 270                ret = PTR_ERR(palmas_rtc->rtc);
 271                dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
 272                return ret;
 273        }
 274
 275        ret = request_threaded_irq(palmas_rtc->irq, NULL,
 276                        palmas_rtc_interrupt,
 277                        IRQF_TRIGGER_LOW | IRQF_ONESHOT |
 278                        IRQF_EARLY_RESUME,
 279                        dev_name(&pdev->dev), palmas_rtc);
 280        if (ret < 0) {
 281                dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
 282                rtc_device_unregister(palmas_rtc->rtc);
 283                return ret;
 284        }
 285
 286        device_set_wakeup_capable(&pdev->dev, 1);
 287        return 0;
 288}
 289
 290static int palmas_rtc_remove(struct platform_device *pdev)
 291{
 292        struct palmas_rtc *palmas_rtc = platform_get_drvdata(pdev);
 293
 294        palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
 295        free_irq(palmas_rtc->irq, palmas_rtc);
 296        rtc_device_unregister(palmas_rtc->rtc);
 297        return 0;
 298}
 299
 300#ifdef CONFIG_PM_SLEEP
 301static int palmas_rtc_suspend(struct device *dev)
 302{
 303        struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
 304
 305        if (device_may_wakeup(dev))
 306                enable_irq_wake(palmas_rtc->irq);
 307        return 0;
 308}
 309
 310static int palmas_rtc_resume(struct device *dev)
 311{
 312        struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
 313
 314        if (device_may_wakeup(dev))
 315                disable_irq_wake(palmas_rtc->irq);
 316        return 0;
 317}
 318#endif
 319
 320static const struct dev_pm_ops palmas_rtc_pm_ops = {
 321        SET_SYSTEM_SLEEP_PM_OPS(palmas_rtc_suspend, palmas_rtc_resume)
 322};
 323
 324static struct platform_driver palmas_rtc_driver = {
 325        .probe          = palmas_rtc_probe,
 326        .remove         = palmas_rtc_remove,
 327        .driver         = {
 328                .owner  = THIS_MODULE,
 329                .name   = "palmas-rtc",
 330                .pm     = &palmas_rtc_pm_ops,
 331        },
 332};
 333
 334module_platform_driver(palmas_rtc_driver);
 335
 336MODULE_ALIAS("platform:palmas_rtc");
 337MODULE_DESCRIPTION("TI PALMAS series RTC driver");
 338MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 339MODULE_LICENSE("GPL v2");
 340
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