--- /dev/null
+/*
+ * RTC driver for Maxim MAX8997
+ *
+ * Copyright (C) 2013 Samsung Electronics Co.Ltd
+ *
+ * based on rtc-max8998.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max8997-private.h>
+#include <linux/irqdomain.h>
+
+/* Module parameter for WTSR function control */
+static int wtsr_en = 1;
+module_param(wtsr_en, int, 0444);
+MODULE_PARM_DESC(wtsr_en, "Watchdog Timeout & Software Reset (default=on)");
+/* Module parameter for SMPL function control */
+static int smpl_en = 1;
+module_param(smpl_en, int, 0444);
+MODULE_PARM_DESC(smpl_en, "Sudden Momentary Power Loss (default=on)");
+
+/* RTC Control Register */
+#define BCD_EN_SHIFT 0
+#define BCD_EN_MASK (1 << BCD_EN_SHIFT)
+#define MODEL24_SHIFT 1
+#define MODEL24_MASK (1 << MODEL24_SHIFT)
+/* RTC Update Register1 */
+#define RTC_UDR_SHIFT 0
+#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT)
+/* WTSR and SMPL Register */
+#define WTSRT_SHIFT 0
+#define SMPLT_SHIFT 2
+#define WTSR_EN_SHIFT 6
+#define SMPL_EN_SHIFT 7
+#define WTSRT_MASK (3 << WTSRT_SHIFT)
+#define SMPLT_MASK (3 << SMPLT_SHIFT)
+#define WTSR_EN_MASK (1 << WTSR_EN_SHIFT)
+#define SMPL_EN_MASK (1 << SMPL_EN_SHIFT)
+/* RTC Hour register */
+#define HOUR_PM_SHIFT 6
+#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT)
+/* RTC Alarm Enable */
+#define ALARM_ENABLE_SHIFT 7
+#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)
+
+enum {
+ RTC_SEC = 0,
+ RTC_MIN,
+ RTC_HOUR,
+ RTC_WEEKDAY,
+ RTC_MONTH,
+ RTC_YEAR,
+ RTC_DATE,
+ RTC_NR_TIME
+};
+
+struct max8997_rtc_info {
+ struct device *dev;
+ struct max8997_dev *max8997;
+ struct i2c_client *rtc;
+ struct rtc_device *rtc_dev;
+ struct mutex lock;
+ int virq;
+ int rtc_24hr_mode;
+};
+
+static void max8997_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
+ int rtc_24hr_mode)
+{
+ tm->tm_sec = data[RTC_SEC] & 0x7f;
+ tm->tm_min = data[RTC_MIN] & 0x7f;
+ if (rtc_24hr_mode)
+ tm->tm_hour = data[RTC_HOUR] & 0x1f;
+ else {
+ tm->tm_hour = data[RTC_HOUR] & 0x0f;
+ if (data[RTC_HOUR] & HOUR_PM_MASK)
+ tm->tm_hour += 12;
+ }
+
+ tm->tm_wday = fls(data[RTC_WEEKDAY] & 0x7f) - 1;
+ tm->tm_mday = data[RTC_DATE] & 0x1f;
+ tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
+ tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;
+ tm->tm_yday = 0;
+ tm->tm_isdst = 0;
+}
+
+static int max8997_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
+{
+ data[RTC_SEC] = tm->tm_sec;
+ data[RTC_MIN] = tm->tm_min;
+ data[RTC_HOUR] = tm->tm_hour;
+ data[RTC_WEEKDAY] = 1 << tm->tm_wday;
+ data[RTC_DATE] = tm->tm_mday;
+ data[RTC_MONTH] = tm->tm_mon + 1;
+ data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;
+
+ if (tm->tm_year < 100) {
+ pr_warn("RTC cannot handle the year %d. Assume it's 2000.\n",
+ 1900 + tm->tm_year);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static inline int max8997_rtc_set_update_reg(struct max8997_rtc_info *info)
+{
+ int ret;
+
+ ret = max8997_write_reg(info->rtc, MAX8997_RTC_UPDATE1,
+ RTC_UDR_MASK);
+ if (ret < 0)
+ dev_err(info->dev, "%s: fail to write update reg(%d)\n",
+ __func__, ret);
+ else {
+ /* Minimum 16ms delay required before RTC update.
+ * Otherwise, we may read and update based on out-of-date
+ * value */
+ msleep(20);
+ }
+
+ return ret;
+}
+
+static int max8997_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ mutex_lock(&info->lock);
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data);
+ mutex_unlock(&info->lock);
+
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__,
+ ret);
+ return ret;
+ }
+
+ max8997_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);
+
+ return rtc_valid_tm(tm);
+}
+
+static int max8997_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ ret = max8997_rtc_tm_to_data(tm, data);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&info->lock);
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
+ ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max8997_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ u8 val;
+ int i, ret;
+
+ mutex_lock(&info->lock);
+
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
+ __func__, __LINE__, ret);
+ goto out;
+ }
+
+ max8997_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);
+
+ alrm->enabled = 0;
+ for (i = 0; i < RTC_NR_TIME; i++) {
+ if (data[i] & ALARM_ENABLE_MASK) {
+ alrm->enabled = 1;
+ break;
+ }
+ }
+
+ alrm->pending = 0;
+ ret = max8997_read_reg(info->max8997->i2c, MAX8997_REG_STATUS1, &val);
+ if (ret < 0) {
+ dev_err(info->dev, "%s:%d fail to read status1 reg(%d)\n",
+ __func__, __LINE__, ret);
+ goto out;
+ }
+
+ if (val & (1 << 4)) /* RTCA1 */
+ alrm->pending = 1;
+
+out:
+ mutex_unlock(&info->lock);
+ return 0;
+}
+
+static int max8997_rtc_stop_alarm(struct max8997_rtc_info *info)
+{
+ u8 data[RTC_NR_TIME];
+ int ret, i;
+
+ if (!mutex_is_locked(&info->lock))
+ dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
+
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ for (i = 0; i < RTC_NR_TIME; i++)
+ data[i] &= ~ALARM_ENABLE_MASK;
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+out:
+ return ret;
+}
+
+static int max8997_rtc_start_alarm(struct max8997_rtc_info *info)
+{
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ if (!mutex_is_locked(&info->lock))
+ dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
+
+ ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
+ data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
+ data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
+ data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
+ if (data[RTC_MONTH] & 0xf)
+ data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
+ if (data[RTC_YEAR] & 0x7f)
+ data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
+ if (data[RTC_DATE] & 0x1f)
+ data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+out:
+ return ret;
+}
+static int max8997_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ ret = max8997_rtc_tm_to_data(&alrm->time, data);
+ if (ret < 0)
+ return ret;
+
+ dev_info(info->dev, "%s: %d-%02d-%02d %02d:%02d:%02d\n", __func__,
+ data[RTC_YEAR] + 2000, data[RTC_MONTH], data[RTC_DATE],
+ data[RTC_HOUR], data[RTC_MIN], data[RTC_SEC]);
+
+ mutex_lock(&info->lock);
+
+ ret = max8997_rtc_stop_alarm(info);
+ if (ret < 0)
+ goto out;
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
+ data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+ if (ret < 0)
+ goto out;
+
+ if (alrm->enabled)
+ ret = max8997_rtc_start_alarm(info);
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max8997_rtc_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct max8997_rtc_info *info = dev_get_drvdata(dev);
+ int ret;
+
+ mutex_lock(&info->lock);
+ if (enabled)
+ ret = max8997_rtc_start_alarm(info);
+ else
+ ret = max8997_rtc_stop_alarm(info);
+ mutex_unlock(&info->lock);
+
+ return ret;
+}
+
+static irqreturn_t max8997_rtc_alarm_irq(int irq, void *data)
+{
+ struct max8997_rtc_info *info = data;
+
+ dev_info(info->dev, "%s:irq(%d)\n", __func__, irq);
+
+ rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
+
+ return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops max8997_rtc_ops = {
+ .read_time = max8997_rtc_read_time,
+ .set_time = max8997_rtc_set_time,
+ .read_alarm = max8997_rtc_read_alarm,
+ .set_alarm = max8997_rtc_set_alarm,
+ .alarm_irq_enable = max8997_rtc_alarm_irq_enable,
+};
+
+static void max8997_rtc_enable_wtsr(struct max8997_rtc_info *info, bool enable)
+{
+ int ret;
+ u8 val, mask;
+
+ if (!wtsr_en)
+ return;
+
+ if (enable)
+ val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT);
+ else
+ val = 0;
+
+ mask = WTSR_EN_MASK | WTSRT_MASK;
+
+ dev_info(info->dev, "%s: %s WTSR\n", __func__,
+ enable ? "enable" : "disable");
+
+ ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
+ __func__, ret);
+ return;
+ }
+
+ max8997_rtc_set_update_reg(info);
+}
+
+static void max8997_rtc_enable_smpl(struct max8997_rtc_info *info, bool enable)
+{
+ int ret;
+ u8 val, mask;
+
+ if (!smpl_en)
+ return;
+
+ if (enable)
+ val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT);
+ else
+ val = 0;
+
+ mask = SMPL_EN_MASK | SMPLT_MASK;
+
+ dev_info(info->dev, "%s: %s SMPL\n", __func__,
+ enable ? "enable" : "disable");
+
+ ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
+ __func__, ret);
+ return;
+ }
+
+ max8997_rtc_set_update_reg(info);
+
+ val = 0;
+ max8997_read_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, &val);
+ pr_info("WTSR_SMPL(0x%02x)\n", val);
+}
+
+static int max8997_rtc_init_reg(struct max8997_rtc_info *info)
+{
+ u8 data[2];
+ int ret;
+
+ /* Set RTC control register : Binary mode, 24hour mdoe */
+ data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
+ data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
+
+ info->rtc_24hr_mode = 1;
+
+ ret = max8997_bulk_write(info->rtc, MAX8997_RTC_CTRLMASK, 2, data);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = max8997_rtc_set_update_reg(info);
+ return ret;
+}
+
+static int max8997_rtc_probe(struct platform_device *pdev)
+{
+ struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent);
+ struct max8997_rtc_info *info;
+ int ret, virq;
+
+ info = devm_kzalloc(&pdev->dev, sizeof(struct max8997_rtc_info),
+ GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ mutex_init(&info->lock);
+ info->dev = &pdev->dev;
+ info->max8997 = max8997;
+ info->rtc = max8997->rtc;
+
+ platform_set_drvdata(pdev, info);
+
+ ret = max8997_rtc_init_reg(info);
+
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
+ return ret;
+ }
+
+ max8997_rtc_enable_wtsr(info, true);
+ max8997_rtc_enable_smpl(info, true);
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8997-rtc",
+ &max8997_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(info->rtc_dev)) {
+ ret = PTR_ERR(info->rtc_dev);
+ dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+ return ret;
+ }
+
+ virq = irq_create_mapping(max8997->irq_domain, MAX8997_PMICIRQ_RTCA1);
+ if (!virq) {
+ dev_err(&pdev->dev, "Failed to create mapping alarm IRQ\n");
+ ret = -ENXIO;
+ goto err_out;
+ }
+ info->virq = virq;
+
+ ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
+ max8997_rtc_alarm_irq, 0,
+ "rtc-alarm0", info);
+ if (ret < 0)
+ dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
+ info->virq, ret);
+
+err_out:
+ return ret;
+}
+
+static void max8997_rtc_shutdown(struct platform_device *pdev)
+{
+ struct max8997_rtc_info *info = platform_get_drvdata(pdev);
+
+ max8997_rtc_enable_wtsr(info, false);
+ max8997_rtc_enable_smpl(info, false);
+}
+
+static const struct platform_device_id rtc_id[] = {
+ { "max8997-rtc", 0 },
+ {},
+};
+
+static struct platform_driver max8997_rtc_driver = {
+ .driver = {
+ .name = "max8997-rtc",
+ },
+ .probe = max8997_rtc_probe,
+ .shutdown = max8997_rtc_shutdown,
+ .id_table = rtc_id,
+};
+
+module_platform_driver(max8997_rtc_driver);
+
+MODULE_DESCRIPTION("Maxim MAX8997 RTC driver");
+MODULE_AUTHOR("<ms925.kim@samsung.com>");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff