--- /dev/null
+/*
+ * Real Time Clock driver for Marvell 88PM860x PMIC
+ *
+ * Copyright (c) 2010 Marvell International Ltd.
+ * Author: Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/88pm860x.h>
+
+#define VRTC_CALIBRATION
+
+struct pm860x_rtc_info {
+ struct pm860x_chip *chip;
+ struct i2c_client *i2c;
+ struct rtc_device *rtc_dev;
+ struct device *dev;
+ struct delayed_work calib_work;
+
+ int irq;
+ int vrtc;
+ int (*sync)(unsigned int ticks);
+};
+
+#define REG_VRTC_MEAS1 0x7D
+
+#define REG0_ADDR 0xB0
+#define REG1_ADDR 0xB2
+#define REG2_ADDR 0xB4
+#define REG3_ADDR 0xB6
+
+#define REG0_DATA 0xB1
+#define REG1_DATA 0xB3
+#define REG2_DATA 0xB5
+#define REG3_DATA 0xB7
+
+/* bit definitions of Measurement Enable Register 2 (0x51) */
+#define MEAS2_VRTC (1 << 0)
+
+/* bit definitions of RTC Register 1 (0xA0) */
+#define ALARM_EN (1 << 3)
+#define ALARM_WAKEUP (1 << 4)
+#define ALARM (1 << 5)
+#define RTC1_USE_XO (1 << 7)
+
+#define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */
+
+static irqreturn_t rtc_update_handler(int irq, void *data)
+{
+ struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
+ int mask;
+
+ mask = ALARM | ALARM_WAKEUP;
+ pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
+ rtc_update_irq(info->rtc_dev, 1, RTC_AF);
+ return IRQ_HANDLED;
+}
+
+static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct pm860x_rtc_info *info = dev_get_drvdata(dev);
+
+ if (enabled)
+ pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM, ALARM);
+ else
+ pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM, 0);
+ return 0;
+}
+
+/*
+ * Calculate the next alarm time given the requested alarm time mask
+ * and the current time.
+ */
+static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
+ struct rtc_time *alrm)
+{
+ unsigned long next_time;
+ unsigned long now_time;
+
+ next->tm_year = now->tm_year;
+ next->tm_mon = now->tm_mon;
+ next->tm_mday = now->tm_mday;
+ next->tm_hour = alrm->tm_hour;
+ next->tm_min = alrm->tm_min;
+ next->tm_sec = alrm->tm_sec;
+
+ rtc_tm_to_time(now, &now_time);
+ rtc_tm_to_time(next, &next_time);
+
+ if (next_time < now_time) {
+ /* Advance one day */
+ next_time += 60 * 60 * 24;
+ rtc_time_to_tm(next_time, next);
+ }
+}
+
+static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pm860x_rtc_info *info = dev_get_drvdata(dev);
+ unsigned char buf[8];
+ unsigned long ticks, base, data;
+
+ pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
+ dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
+ buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
+ base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
+
+ /* load 32-bit read-only counter */
+ pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
+ data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
+ ticks = base + data;
+ dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
+ base, data, ticks);
+
+ rtc_time_to_tm(ticks, tm);
+
+ return 0;
+}
+
+static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct pm860x_rtc_info *info = dev_get_drvdata(dev);
+ unsigned char buf[4];
+ unsigned long ticks, base, data;
+
+ if ((tm->tm_year < 70) || (tm->tm_year > 138)) {
+ dev_dbg(info->dev, "Set time %d out of range. "
+ "Please set time between 1970 to 2038.\n",
+ 1900 + tm->tm_year);
+ return -EINVAL;
+ }
+ rtc_tm_to_time(tm, &ticks);
+
+ /* load 32-bit read-only counter */
+ pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
+ data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
+ base = ticks - data;
+ dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
+ base, data, ticks);
+
+ pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
+ pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
+ pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
+ pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
+
+ if (info->sync)
+ info->sync(ticks);
+ return 0;
+}
+
+static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct pm860x_rtc_info *info = dev_get_drvdata(dev);
+ unsigned char buf[8];
+ unsigned long ticks, base, data;
+ int ret;
+
+ pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
+ dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
+ buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
+ base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
+
+ pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
+ data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
+ ticks = base + data;
+ dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
+ base, data, ticks);
+
+ rtc_time_to_tm(ticks, &alrm->time);
+ ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
+ alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
+ alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
+ return 0;
+}
+
+static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct pm860x_rtc_info *info = dev_get_drvdata(dev);
+ struct rtc_time now_tm, alarm_tm;
+ unsigned long ticks, base, data;
+ unsigned char buf[8];
+ int mask;
+
+ pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
+
+ pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
+ dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
+ buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
+ base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
+
+ /* load 32-bit read-only counter */
+ pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
+ data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
+ ticks = base + data;
+ dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
+ base, data, ticks);
+
+ rtc_time_to_tm(ticks, &now_tm);
+ rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
+ /* get new ticks for alarm in 24 hours */
+ rtc_tm_to_time(&alarm_tm, &ticks);
+ data = ticks - base;
+
+ buf[0] = data & 0xff;
+ buf[1] = (data >> 8) & 0xff;
+ buf[2] = (data >> 16) & 0xff;
+ buf[3] = (data >> 24) & 0xff;
+ pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
+ if (alrm->enabled) {
+ mask = ALARM | ALARM_WAKEUP | ALARM_EN;
+ pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
+ } else {
+ mask = ALARM | ALARM_WAKEUP | ALARM_EN;
+ pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
+ ALARM | ALARM_WAKEUP);
+ }
+ return 0;
+}
+
+static const struct rtc_class_ops pm860x_rtc_ops = {
+ .read_time = pm860x_rtc_read_time,
+ .set_time = pm860x_rtc_set_time,
+ .read_alarm = pm860x_rtc_read_alarm,
+ .set_alarm = pm860x_rtc_set_alarm,
+ .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
+};
+
+#ifdef VRTC_CALIBRATION
+static void calibrate_vrtc_work(struct work_struct *work)
+{
+ struct pm860x_rtc_info *info = container_of(work,
+ struct pm860x_rtc_info, calib_work.work);
+ unsigned char buf[2];
+ unsigned int sum, data, mean, vrtc_set;
+ int i;
+
+ for (i = 0, sum = 0; i < 16; i++) {
+ msleep(100);
+ pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
+ data = (buf[0] << 4) | buf[1];
+ data = (data * 5400) >> 12; /* convert to mv */
+ sum += data;
+ }
+ mean = sum >> 4;
+ vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
+ dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
+
+ sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
+ data = sum & 0x3;
+ if ((mean + 200) < vrtc_set) {
+ /* try higher voltage */
+ if (++data == 4)
+ goto out;
+ data = (sum & 0xf8) | (data & 0x3);
+ pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
+ } else if ((mean - 200) > vrtc_set) {
+ /* try lower voltage */
+ if (data-- == 0)
+ goto out;
+ data = (sum & 0xf8) | (data & 0x3);
+ pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
+ } else
+ goto out;
+ dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
+ /* trigger next calibration since VRTC is updated */
+ schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
+ return;
+out:
+ /* disable measurement */
+ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
+ dev_dbg(info->dev, "finish VRTC calibration\n");
+ return;
+}
+#endif
+
+static int __devinit pm860x_rtc_probe(struct platform_device *pdev)
+{
+ struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
+ struct pm860x_rtc_pdata *pdata = NULL;
+ struct pm860x_rtc_info *info;
+ struct rtc_time tm;
+ unsigned long ticks = 0;
+ int ret;
+
+ pdata = pdev->dev.platform_data;
+ if (pdata == NULL)
+ dev_warn(&pdev->dev, "No platform data!\n");
+
+ info = kzalloc(sizeof(struct pm860x_rtc_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ info->irq = platform_get_irq(pdev, 0);
+ if (info->irq < 0) {
+ dev_err(&pdev->dev, "No IRQ resource!\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ info->chip = chip;
+ info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
+ info->dev = &pdev->dev;
+ dev_set_drvdata(&pdev->dev, info);
+
+ ret = request_threaded_irq(info->irq, NULL, rtc_update_handler,
+ IRQF_ONESHOT, "rtc", info);
+ if (ret < 0) {
+ dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
+ info->irq, ret);
+ goto out;
+ }
+
+ /* set addresses of 32-bit base value for RTC time */
+ pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
+ pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
+ pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
+ pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
+
+ ret = pm860x_rtc_read_time(&pdev->dev, &tm);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to read initial time.\n");
+ goto out_rtc;
+ }
+ if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
+ tm.tm_year = 70;
+ tm.tm_mon = 0;
+ tm.tm_mday = 1;
+ tm.tm_hour = 0;
+ tm.tm_min = 0;
+ tm.tm_sec = 0;
+ ret = pm860x_rtc_set_time(&pdev->dev, &tm);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to set initial time.\n");
+ goto out_rtc;
+ }
+ }
+ rtc_tm_to_time(&tm, &ticks);
+ if (pdata && pdata->sync) {
+ pdata->sync(ticks);
+ info->sync = pdata->sync;
+ }
+
+ info->rtc_dev = rtc_device_register("88pm860x-rtc", &pdev->dev,
+ &pm860x_rtc_ops, THIS_MODULE);
+ ret = PTR_ERR(info->rtc_dev);
+ if (IS_ERR(info->rtc_dev)) {
+ dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+ goto out_rtc;
+ }
+
+ /*
+ * enable internal XO instead of internal 3.25MHz clock since it can
+ * free running in PMIC power-down state.
+ */
+ pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
+
+#ifdef VRTC_CALIBRATION
+ /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
+ if (pdata && pdata->vrtc)
+ info->vrtc = pdata->vrtc & 0x3;
+ else
+ info->vrtc = 1;
+ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
+
+ /* calibrate VRTC */
+ INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
+ schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
+#endif /* VRTC_CALIBRATION */
+ return 0;
+out_rtc:
+ free_irq(info->irq, info);
+out:
+ kfree(info);
+ return ret;
+}
+
+static int __devexit pm860x_rtc_remove(struct platform_device *pdev)
+{
+ struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
+
+#ifdef VRTC_CALIBRATION
+ flush_scheduled_work();
+ /* disable measurement */
+ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
+#endif /* VRTC_CALIBRATION */
+
+ platform_set_drvdata(pdev, NULL);
+ rtc_device_unregister(info->rtc_dev);
+ free_irq(info->irq, info);
+ kfree(info);
+ return 0;
+}
+
+static struct platform_driver pm860x_rtc_driver = {
+ .driver = {
+ .name = "88pm860x-rtc",
+ .owner = THIS_MODULE,
+ },
+ .probe = pm860x_rtc_probe,
+ .remove = __devexit_p(pm860x_rtc_remove),
+};
+
+static int __init pm860x_rtc_init(void)
+{
+ return platform_driver_register(&pm860x_rtc_driver);
+}
+module_init(pm860x_rtc_init);
+
+static void __exit pm860x_rtc_exit(void)
+{
+ platform_driver_unregister(&pm860x_rtc_driver);
+}
+module_exit(pm860x_rtc_exit);
+
+MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-arm64.git / commitdiff