linux/drivers/rtc/rtc-palmas.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * rtc-palmas.c -- Palmas Real Time Clock driver.
   4
   5 * RTC driver for TI Palma series devices like TPS65913,
   6 * TPS65914 power management IC.
   7 *
   8 * Copyright (c) 2012, NVIDIA Corporation.
   9 *
  10 * Author: Laxman Dewangan <ldewangan@nvidia.com>
  11 */
  12
  13#include <linux/bcd.h>
  14#include <linux/errno.h>
  15#include <linux/init.h>
  16#include <linux/interrupt.h>
  17#include <linux/kernel.h>
  18#include <linux/mfd/palmas.h>
  19#include <linux/module.h>
  20#include <linux/of.h>
  21#include <linux/rtc.h>
  22#include <linux/types.h>
  23#include <linux/platform_device.h>
  24#include <linux/pm.h>
  25
  26struct palmas_rtc {
  27        struct rtc_device       *rtc;
  28        struct device           *dev;
  29        unsigned int            irq;
  30};
  31
  32/* Total number of RTC registers needed to set time*/
  33#define PALMAS_NUM_TIME_REGS    (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
  34
  35static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
  36{
  37        unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
  38        struct palmas *palmas = dev_get_drvdata(dev->parent);
  39        int ret;
  40
  41        /* Copy RTC counting registers to static registers or latches */
  42        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
  43                PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
  44        if (ret < 0) {
  45                dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
  46                return ret;
  47        }
  48
  49        ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
  50                        rtc_data, PALMAS_NUM_TIME_REGS);
  51        if (ret < 0) {
  52                dev_err(dev, "RTC_SECONDS reg read failed, err = %d\n", ret);
  53                return ret;
  54        }
  55
  56        tm->tm_sec = bcd2bin(rtc_data[0]);
  57        tm->tm_min = bcd2bin(rtc_data[1]);
  58        tm->tm_hour = bcd2bin(rtc_data[2]);
  59        tm->tm_mday = bcd2bin(rtc_data[3]);
  60        tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
  61        tm->tm_year = bcd2bin(rtc_data[5]) + 100;
  62
  63        return ret;
  64}
  65
  66static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
  67{
  68        unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
  69        struct palmas *palmas = dev_get_drvdata(dev->parent);
  70        int ret;
  71
  72        rtc_data[0] = bin2bcd(tm->tm_sec);
  73        rtc_data[1] = bin2bcd(tm->tm_min);
  74        rtc_data[2] = bin2bcd(tm->tm_hour);
  75        rtc_data[3] = bin2bcd(tm->tm_mday);
  76        rtc_data[4] = bin2bcd(tm->tm_mon + 1);
  77        rtc_data[5] = bin2bcd(tm->tm_year - 100);
  78
  79        /* Stop RTC while updating the RTC time registers */
  80        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
  81                PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
  82        if (ret < 0) {
  83                dev_err(dev, "RTC stop failed, err = %d\n", ret);
  84                return ret;
  85        }
  86
  87        ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
  88                rtc_data, PALMAS_NUM_TIME_REGS);
  89        if (ret < 0) {
  90                dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
  91                return ret;
  92        }
  93
  94        /* Start back RTC */
  95        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
  96                PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
  97        if (ret < 0)
  98                dev_err(dev, "RTC start failed, err = %d\n", ret);
  99        return ret;
 100}
 101
 102static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
 103{
 104        struct palmas *palmas = dev_get_drvdata(dev->parent);
 105        u8 val;
 106
 107        val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
 108        return palmas_write(palmas, PALMAS_RTC_BASE,
 109                PALMAS_RTC_INTERRUPTS_REG, val);
 110}
 111
 112static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 113{
 114        unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
 115        u32 int_val;
 116        struct palmas *palmas = dev_get_drvdata(dev->parent);
 117        int ret;
 118
 119        ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
 120                        PALMAS_ALARM_SECONDS_REG,
 121                        alarm_data, PALMAS_NUM_TIME_REGS);
 122        if (ret < 0) {
 123                dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %d\n", ret);
 124                return ret;
 125        }
 126
 127        alm->time.tm_sec = bcd2bin(alarm_data[0]);
 128        alm->time.tm_min = bcd2bin(alarm_data[1]);
 129        alm->time.tm_hour = bcd2bin(alarm_data[2]);
 130        alm->time.tm_mday = bcd2bin(alarm_data[3]);
 131        alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
 132        alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
 133
 134        ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
 135                        &int_val);
 136        if (ret < 0) {
 137                dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
 138                return ret;
 139        }
 140
 141        if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
 142                alm->enabled = 1;
 143        return ret;
 144}
 145
 146static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 147{
 148        unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
 149        struct palmas *palmas = dev_get_drvdata(dev->parent);
 150        int ret;
 151
 152        ret = palmas_rtc_alarm_irq_enable(dev, 0);
 153        if (ret < 0) {
 154                dev_err(dev, "Disable RTC alarm failed\n");
 155                return ret;
 156        }
 157
 158        alarm_data[0] = bin2bcd(alm->time.tm_sec);
 159        alarm_data[1] = bin2bcd(alm->time.tm_min);
 160        alarm_data[2] = bin2bcd(alm->time.tm_hour);
 161        alarm_data[3] = bin2bcd(alm->time.tm_mday);
 162        alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
 163        alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
 164
 165        ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
 166                PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
 167        if (ret < 0) {
 168                dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
 169                return ret;
 170        }
 171
 172        if (alm->enabled)
 173                ret = palmas_rtc_alarm_irq_enable(dev, 1);
 174        return ret;
 175}
 176
 177static int palmas_clear_interrupts(struct device *dev)
 178{
 179        struct palmas *palmas = dev_get_drvdata(dev->parent);
 180        unsigned int rtc_reg;
 181        int ret;
 182
 183        ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
 184                                &rtc_reg);
 185        if (ret < 0) {
 186                dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
 187                return ret;
 188        }
 189
 190        ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
 191                        rtc_reg);
 192        if (ret < 0) {
 193                dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
 194                return ret;
 195        }
 196        return 0;
 197}
 198
 199static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
 200{
 201        struct palmas_rtc *palmas_rtc = context;
 202        struct device *dev = palmas_rtc->dev;
 203        int ret;
 204
 205        ret = palmas_clear_interrupts(dev);
 206        if (ret < 0) {
 207                dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
 208                return IRQ_NONE;
 209        }
 210
 211        rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
 212        return IRQ_HANDLED;
 213}
 214
 215static const struct rtc_class_ops palmas_rtc_ops = {
 216        .read_time      = palmas_rtc_read_time,
 217        .set_time       = palmas_rtc_set_time,
 218        .read_alarm     = palmas_rtc_read_alarm,
 219        .set_alarm      = palmas_rtc_set_alarm,
 220        .alarm_irq_enable = palmas_rtc_alarm_irq_enable,
 221};
 222
 223static int palmas_rtc_probe(struct platform_device *pdev)
 224{
 225        struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
 226        struct palmas_rtc *palmas_rtc = NULL;
 227        int ret;
 228        bool enable_bb_charging = false;
 229        bool high_bb_charging = false;
 230
 231        if (pdev->dev.of_node) {
 232                enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
 233                                        "ti,backup-battery-chargeable");
 234                high_bb_charging = of_property_read_bool(pdev->dev.of_node,
 235                                        "ti,backup-battery-charge-high-current");
 236        }
 237
 238        palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
 239                        GFP_KERNEL);
 240        if (!palmas_rtc)
 241                return -ENOMEM;
 242
 243        /* Clear pending interrupts */
 244        ret = palmas_clear_interrupts(&pdev->dev);
 245        if (ret < 0) {
 246                dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
 247                return ret;
 248        }
 249
 250        palmas_rtc->dev = &pdev->dev;
 251        platform_set_drvdata(pdev, palmas_rtc);
 252
 253        if (enable_bb_charging) {
 254                unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;
 255
 256                if (high_bb_charging)
 257                        reg = 0;
 258
 259                ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
 260                        PALMAS_BACKUP_BATTERY_CTRL,
 261                        PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg);
 262                if (ret < 0) {
 263                        dev_err(&pdev->dev,
 264                                "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
 265                        return ret;
 266                }
 267
 268                ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
 269                        PALMAS_BACKUP_BATTERY_CTRL,
 270                        PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN,
 271                        PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN);
 272                if (ret < 0) {
 273                        dev_err(&pdev->dev,
 274                                "BACKUP_BATTERY_CTRL update failed, %d\n", ret);
 275                        return ret;
 276                }
 277        }
 278
 279        /* Start RTC */
 280        ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
 281                        PALMAS_RTC_CTRL_REG_STOP_RTC,
 282                        PALMAS_RTC_CTRL_REG_STOP_RTC);
 283        if (ret < 0) {
 284                dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
 285                return ret;
 286        }
 287
 288        palmas_rtc->irq = platform_get_irq(pdev, 0);
 289
 290        device_init_wakeup(&pdev->dev, 1);
 291        palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 292                                &palmas_rtc_ops, THIS_MODULE);
 293        if (IS_ERR(palmas_rtc->rtc)) {
 294                ret = PTR_ERR(palmas_rtc->rtc);
 295                dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
 296                return ret;
 297        }
 298
 299        ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
 300                        palmas_rtc_interrupt,
 301                        IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 302                        dev_name(&pdev->dev), palmas_rtc);
 303        if (ret < 0) {
 304                dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
 305                return ret;
 306        }
 307
 308        return 0;
 309}
 310
 311static int palmas_rtc_remove(struct platform_device *pdev)
 312{
 313        palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
 314        return 0;
 315}
 316
 317#ifdef CONFIG_PM_SLEEP
 318static int palmas_rtc_suspend(struct device *dev)
 319{
 320        struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
 321
 322        if (device_may_wakeup(dev))
 323                enable_irq_wake(palmas_rtc->irq);
 324        return 0;
 325}
 326
 327static int palmas_rtc_resume(struct device *dev)
 328{
 329        struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
 330
 331        if (device_may_wakeup(dev))
 332                disable_irq_wake(palmas_rtc->irq);
 333        return 0;
 334}
 335#endif
 336
 337static SIMPLE_DEV_PM_OPS(palmas_rtc_pm_ops, palmas_rtc_suspend,
 338                         palmas_rtc_resume);
 339
 340#ifdef CONFIG_OF
 341static const struct of_device_id of_palmas_rtc_match[] = {
 342        { .compatible = "ti,palmas-rtc"},
 343        { },
 344};
 345MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
 346#endif
 347
 348static struct platform_driver palmas_rtc_driver = {
 349        .probe          = palmas_rtc_probe,
 350        .remove         = palmas_rtc_remove,
 351        .driver         = {
 352                .name   = "palmas-rtc",
 353                .pm     = &palmas_rtc_pm_ops,
 354                .of_match_table = of_match_ptr(of_palmas_rtc_match),
 355        },
 356};
 357
 358module_platform_driver(palmas_rtc_driver);
 359
 360MODULE_ALIAS("platform:palmas_rtc");
 361MODULE_DESCRIPTION("TI PALMAS series RTC driver");
 362MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 363MODULE_LICENSE("GPL v2");
 364