--- /dev/null
+/*
+ * RTC driver for Maxim MAX77686
+ *
+ * Copyright (C) 2012 Samsung Electronics Co.Ltd
+ *
+ * based on rtc-max8997.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.
+ *
+ */
+
+#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/max77686-private.h>
+#include <linux/irqdomain.h>
+#include <linux/regmap.h>
+
+/* 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)
+#define RTC_RBUDR_SHIFT 4
+#define RTC_RBUDR_MASK (1 << RTC_RBUDR_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)
+
+#define MAX77686_RTC_UPDATE_DELAY 16
+#undef MAX77686_RTC_WTSR_SMPL
+
+enum {
+ RTC_SEC = 0,
+ RTC_MIN,
+ RTC_HOUR,
+ RTC_WEEKDAY,
+ RTC_MONTH,
+ RTC_YEAR,
+ RTC_DATE,
+ RTC_NR_TIME
+};
+
+struct max77686_rtc_info {
+ struct device *dev;
+ struct max77686_dev *max77686;
+ struct i2c_client *rtc;
+ struct rtc_device *rtc_dev;
+ struct mutex lock;
+
+ struct regmap *regmap;
+
+ int virq;
+ int rtc_24hr_mode;
+};
+
+enum MAX77686_RTC_OP {
+ MAX77686_RTC_WRITE,
+ MAX77686_RTC_READ,
+};
+
+static inline int max77686_rtc_calculate_wday(u8 shifted)
+{
+ int counter = -1;
+ while (shifted) {
+ shifted >>= 1;
+ counter++;
+ }
+ return counter;
+}
+
+static void max77686_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 = max77686_rtc_calculate_wday(data[RTC_WEEKDAY] & 0x7f);
+ 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 max77686_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("%s: MAX77686 RTC cannot handle the year %d."
+ "Assume it's 2000.\n", __func__, 1900 + tm->tm_year);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static inline int max77686_rtc_update(struct max77686_rtc_info *info,
+ enum MAX77686_RTC_OP op)
+{
+ int ret;
+ unsigned int data;
+
+ switch (op) {
+ case MAX77686_RTC_WRITE:
+ data = 1 << RTC_UDR_SHIFT;
+ break;
+ case MAX77686_RTC_READ:
+ data = 1 << RTC_RBUDR_SHIFT;
+ break;
+ }
+
+ ret = regmap_update_bits(info->max77686->rtc_regmap,
+ MAX77686_RTC_UPDATE0, data, data);
+ if (ret < 0)
+ dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n",
+ __func__, ret, data);
+ else {
+ /* Minimum 16ms delay required before RTC update. */
+ msleep(MAX77686_RTC_UPDATE_DELAY);
+ }
+
+ return ret;
+}
+
+static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max77686_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ mutex_lock(&info->lock);
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_READ);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_bulk_read(info->max77686->rtc_regmap,
+ MAX77686_RTC_SEC, data, RTC_NR_TIME);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, ret);
+ goto out;
+ }
+
+ max77686_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);
+
+ ret = rtc_valid_tm(tm);
+
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct max77686_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ ret = max77686_rtc_tm_to_data(tm, data);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&info->lock);
+
+ ret = regmap_bulk_write(info->max77686->rtc_regmap,
+ MAX77686_RTC_SEC, data, RTC_NR_TIME);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
+ ret);
+ goto out;
+ }
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
+
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max77686_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ unsigned int val;
+ int i, ret;
+
+ mutex_lock(&info->lock);
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_READ);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_bulk_read(info->max77686->rtc_regmap,
+ MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
+ if (ret < 0) {
+ dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
+ __func__, __LINE__, ret);
+ goto out;
+ }
+
+ max77686_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 = regmap_read(info->max77686->regmap, MAX77686_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 max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
+{
+ u8 data[RTC_NR_TIME];
+ int ret, i;
+ struct rtc_time tm;
+
+ if (!mutex_is_locked(&info->lock))
+ dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_READ);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_bulk_read(info->max77686->rtc_regmap,
+ MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
+
+ for (i = 0; i < RTC_NR_TIME; i++)
+ data[i] &= ~ALARM_ENABLE_MASK;
+
+ ret = regmap_bulk_write(info->max77686->rtc_regmap,
+ MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
+out:
+ return ret;
+}
+
+static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
+{
+ u8 data[RTC_NR_TIME];
+ int ret;
+ struct rtc_time tm;
+
+ if (!mutex_is_locked(&info->lock))
+ dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_READ);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_bulk_read(info->max77686->rtc_regmap,
+ MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ max77686_rtc_data_to_tm(data, &tm, info->rtc_24hr_mode);
+
+ 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 = regmap_bulk_write(info->max77686->rtc_regmap,
+ MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
+out:
+ return ret;
+}
+
+static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct max77686_rtc_info *info = dev_get_drvdata(dev);
+ u8 data[RTC_NR_TIME];
+ int ret;
+
+ ret = max77686_rtc_tm_to_data(&alrm->time, data);
+ if (ret < 0)
+ return ret;
+
+ mutex_lock(&info->lock);
+
+ ret = max77686_rtc_stop_alarm(info);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_bulk_write(info->max77686->rtc_regmap,
+ MAX77686_ALARM1_SEC, data, RTC_NR_TIME);
+
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
+ __func__, ret);
+ goto out;
+ }
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
+ if (ret < 0)
+ goto out;
+
+ if (alrm->enabled)
+ ret = max77686_rtc_start_alarm(info);
+out:
+ mutex_unlock(&info->lock);
+ return ret;
+}
+
+static int max77686_rtc_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct max77686_rtc_info *info = dev_get_drvdata(dev);
+ int ret;
+
+ mutex_lock(&info->lock);
+ if (enabled)
+ ret = max77686_rtc_start_alarm(info);
+ else
+ ret = max77686_rtc_stop_alarm(info);
+ mutex_unlock(&info->lock);
+
+ return ret;
+}
+
+static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
+{
+ struct max77686_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 max77686_rtc_ops = {
+ .read_time = max77686_rtc_read_time,
+ .set_time = max77686_rtc_set_time,
+ .read_alarm = max77686_rtc_read_alarm,
+ .set_alarm = max77686_rtc_set_alarm,
+ .alarm_irq_enable = max77686_rtc_alarm_irq_enable,
+};
+
+#ifdef MAX77686_RTC_WTSR_SMPL
+static void max77686_rtc_enable_wtsr(struct max77686_rtc_info *info, bool enable)
+{
+ int ret;
+ unsigned int val, mask;
+
+ 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 = regmap_update_bits(info->max77686->rtc_regmap,
+ MAX77686_WTSR_SMPL_CNTL, mask, val);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
+ __func__, ret);
+ return;
+ }
+
+ max77686_rtc_update(info, MAX77686_RTC_WRITE);
+}
+
+static void max77686_rtc_enable_smpl(struct max77686_rtc_info *info, bool enable)
+{
+ int ret;
+ unsigned int val, mask;
+
+ 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 = regmap_update_bits(info->max77686->rtc_regmap,
+ MAX77686_WTSR_SMPL_CNTL, mask, val);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
+ __func__, ret);
+ return;
+ }
+
+ max77686_rtc_update(info, MAX77686_RTC_WRITE);
+
+ val = 0;
+ regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
+ pr_info("%s: WTSR_SMPL(0x%02x)\n", __func__, val);
+}
+#endif /* MAX77686_RTC_WTSR_SMPL */
+
+static int max77686_rtc_init_reg(struct max77686_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 = regmap_bulk_write(info->max77686->rtc_regmap, MAX77686_RTC_CONTROLM, data, 2);
+ if (ret < 0) {
+ dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
+ return ret;
+}
+
+static struct regmap_config max77686_rtc_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int max77686_rtc_probe(struct platform_device *pdev)
+{
+ struct max77686_dev *max77686 = dev_get_drvdata(pdev->dev.parent);
+ struct max77686_rtc_info *info;
+ int ret, virq;
+
+ printk(KERN_INFO "%s\n", __func__);
+
+ info = kzalloc(sizeof(struct max77686_rtc_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ mutex_init(&info->lock);
+ info->dev = &pdev->dev;
+ info->max77686 = max77686;
+ info->rtc = max77686->rtc;
+ info->max77686->rtc_regmap = regmap_init_i2c(info->max77686->rtc,
+ &max77686_rtc_regmap_config);
+ if (IS_ERR(info->max77686->rtc_regmap)) {
+ ret = PTR_ERR(info->max77686->rtc_regmap);
+ dev_err(info->max77686->dev, "Failed to allocate register map: %d\n",
+ ret);
+ kfree(info);
+ return ret;
+ }
+ platform_set_drvdata(pdev, info);
+
+ ret = max77686_rtc_init_reg(info);
+
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
+ goto err_rtc;
+ }
+
+#ifdef MAX77686_RTC_WTSR_SMPL
+ max77686_rtc_enable_wtsr(info, true);
+ max77686_rtc_enable_smpl(info, true);
+#endif
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ info->rtc_dev = rtc_device_register("max77686-rtc", &pdev->dev,
+ &max77686_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(info->rtc_dev)) {
+ printk(KERN_INFO "%s: fail\n", __func__);
+
+ ret = PTR_ERR(info->rtc_dev);
+ dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+ if (ret == 0)
+ ret = -EINVAL;
+ goto err_rtc;
+ }
+ virq = irq_create_mapping(max77686->irq_domain, MAX77686_RTCIRQ_RTCA1);
+ if (!virq)
+ goto err_rtc;
+ info->virq = virq;
+
+ ret = request_threaded_irq(virq, NULL, max77686_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);
+ goto err_rtc;
+ }
+
+ goto out;
+err_rtc:
+ kfree(info);
+ return ret;
+out:
+ return ret;
+}
+
+static int max77686_rtc_remove(struct platform_device *pdev)
+{
+ struct max77686_rtc_info *info = platform_get_drvdata(pdev);
+
+ if (info) {
+ free_irq(info->virq, info);
+ rtc_device_unregister(info->rtc_dev);
+ kfree(info);
+ }
+
+ return 0;
+}
+
+static void max77686_rtc_shutdown(struct platform_device *pdev)
+{
+#ifdef MAX77686_RTC_WTSR_SMPL
+ struct max77686_rtc_info *info = platform_get_drvdata(pdev);
+ int i;
+ u8 val = 0;
+
+ for (i = 0; i < 3; i++) {
+ max77686_rtc_enable_wtsr(info, false);
+ regmap_read(info->max77686->rtc_regmap, MAX77686_WTSR_SMPL_CNTL, &val);
+ pr_info("%s: WTSR_SMPL reg(0x%02x)\n", __func__, val);
+ if (val & WTSR_EN_MASK)
+ pr_emerg("%s: fail to disable WTSR\n", __func__);
+ else {
+ pr_info("%s: success to disable WTSR\n", __func__);
+ break;
+ }
+ }
+
+ /* Disable SMPL when power off */
+ max77686_rtc_enable_smpl(info, false);
+#endif /* MAX77686_RTC_WTSR_SMPL */
+}
+
+static const struct platform_device_id rtc_id[] = {
+ { "max77686-rtc", 0 },
+ {},
+};
+
+static struct platform_driver max77686_rtc_driver = {
+ .driver = {
+ .name = "max77686-rtc",
+ .owner = THIS_MODULE,
+ },
+ .probe = max77686_rtc_probe,
+ .remove = max77686_rtc_remove,
+ .shutdown = max77686_rtc_shutdown,
+ .id_table = rtc_id,
+};
+
+static int __init max77686_rtc_init(void)
+{
+ return platform_driver_register(&max77686_rtc_driver);
+}
+module_init(max77686_rtc_init);
+
+static void __exit max77686_rtc_exit(void)
+{
+ platform_driver_unregister(&max77686_rtc_driver);
+}
+module_exit(max77686_rtc_exit);
+
+MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
+MODULE_AUTHOR("<woong.byun@samsung.com>");
+MODULE_LICENSE("GPL");
projects / karo-tx-linux.git / commitdiff