Initial import

1 files changed, 420 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-rk808.c b/drivers/rtc/rtc-rk808.c
new file mode 100644
index 000000000..91ca0bc1b
--- /dev/null
+++ b/drivers/rtc/rtc-rk808.c
@@ -0,0 +1,420 @@
+/*
+ * RTC driver for Rockchip RK808
+ *
+ * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * Author: Chris Zhong <zyw@rock-chips.com>
+ * Author: Zhang Qing <zhangqing@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/mfd/rk808.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+
+/* RTC_CTRL_REG bitfields */
+#define BIT_RTC_CTRL_REG_STOP_RTC_M		BIT(0)
+
+/* RK808 has a shadowed register for saving a "frozen" RTC time.
+ * When user setting "GET_TIME" to 1, the time will save in this shadowed
+ * register. If set "READSEL" to 1, user read rtc time register, actually
+ * get the time of that moment. If we need the real time, clr this bit.
+ */
+#define BIT_RTC_CTRL_REG_RTC_GET_TIME		BIT(6)
+#define BIT_RTC_CTRL_REG_RTC_READSEL_M		BIT(7)
+#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M	BIT(3)
+#define RTC_STATUS_MASK		0xFE
+
+#define SECONDS_REG_MSK		0x7F
+#define MINUTES_REG_MAK		0x7F
+#define HOURS_REG_MSK		0x3F
+#define DAYS_REG_MSK		0x3F
+#define MONTHS_REG_MSK		0x1F
+#define YEARS_REG_MSK		0xFF
+#define WEEKS_REG_MSK		0x7
+
+/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
+
+#define NUM_TIME_REGS	(RK808_WEEKS_REG - RK808_SECONDS_REG + 1)
+#define NUM_ALARM_REGS	(RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)
+
+struct rk808_rtc {
+	struct rk808 *rk808;
+	struct rtc_device *rtc;
+	int irq;
+};
+
+/* Read current time and date in RTC */
+static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
+	struct rk808 *rk808 = rk808_rtc->rk808;
+	u8 rtc_data[NUM_TIME_REGS];
+	int ret;
+
+	/* Force an update of the shadowed registers right now */
+	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
+				 BIT_RTC_CTRL_REG_RTC_GET_TIME,
+				 BIT_RTC_CTRL_REG_RTC_GET_TIME);
+	if (ret) {
+		dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * After we set the GET_TIME bit, the rtc time can't be read
+	 * immediately. So we should wait up to 31.25 us, about one cycle of
+	 * 32khz. If we clear the GET_TIME bit here, the time of i2c transfer
+	 * certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.
+	 */
+	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
+				 BIT_RTC_CTRL_REG_RTC_GET_TIME,
+				 0);
+	if (ret) {
+		dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_bulk_read(rk808->regmap, RK808_SECONDS_REG,
+			       rtc_data, NUM_TIME_REGS);
+	if (ret) {
+		dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);
+		return ret;
+	}
+
+	tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
+	tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
+	tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
+	tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
+	tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;
+	tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
+	tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
+	dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
+		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
+		tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);
+
+	return ret;
+}
+
+/* Set current time and date in RTC */
+static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
+	struct rk808 *rk808 = rk808_rtc->rk808;
+	u8 rtc_data[NUM_TIME_REGS];
+	int ret;
+
+	rtc_data[0] = bin2bcd(tm->tm_sec);
+	rtc_data[1] = bin2bcd(tm->tm_min);
+	rtc_data[2] = bin2bcd(tm->tm_hour);
+	rtc_data[3] = bin2bcd(tm->tm_mday);
+	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
+	rtc_data[5] = bin2bcd(tm->tm_year - 100);
+	rtc_data[6] = bin2bcd(tm->tm_wday);
+	dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
+		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
+		tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);
+
+	/* Stop RTC while updating the RTC registers */
+	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
+				 BIT_RTC_CTRL_REG_STOP_RTC_M,
+				 BIT_RTC_CTRL_REG_STOP_RTC_M);
+	if (ret) {
+		dev_err(dev, "Failed to update RTC control: %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_bulk_write(rk808->regmap, RK808_SECONDS_REG,
+				rtc_data, NUM_TIME_REGS);
+	if (ret) {
+		dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);
+		return ret;
+	}
+	/* Start RTC again */
+	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
+				 BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
+	if (ret) {
+		dev_err(dev, "Failed to update RTC control: %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+/* Read alarm time and date in RTC */
+static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
+	struct rk808 *rk808 = rk808_rtc->rk808;
+	u8 alrm_data[NUM_ALARM_REGS];
+	uint32_t int_reg;
+	int ret;
+
+	ret = regmap_bulk_read(rk808->regmap, RK808_ALARM_SECONDS_REG,
+			       alrm_data, NUM_ALARM_REGS);
+
+	alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);
+	alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);
+	alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);
+	alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);
+	alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;
+	alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;
+
+	ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg);
+	if (ret) {
+		dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);
+		return ret;
+	}
+
+	dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
+		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
+		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
+		alrm->time.tm_min, alrm->time.tm_sec);
+
+	alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
+
+	return 0;
+}
+
+static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)
+{
+	struct rk808 *rk808 = rk808_rtc->rk808;
+	int ret;
+
+	ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
+				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);
+
+	return ret;
+}
+
+static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)
+{
+	struct rk808 *rk808 = rk808_rtc->rk808;
+	int ret;
+
+	ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
+				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,
+				 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+
+	return ret;
+}
+
+static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
+	struct rk808 *rk808 = rk808_rtc->rk808;
+	u8 alrm_data[NUM_ALARM_REGS];
+	int ret;
+
+	ret = rk808_rtc_stop_alarm(rk808_rtc);
+	if (ret) {
+		dev_err(dev, "Failed to stop alarm: %d\n", ret);
+		return ret;
+	}
+	dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
+		1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
+		alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
+		alrm->time.tm_min, alrm->time.tm_sec);
+
+	alrm_data[0] = bin2bcd(alrm->time.tm_sec);
+	alrm_data[1] = bin2bcd(alrm->time.tm_min);
+	alrm_data[2] = bin2bcd(alrm->time.tm_hour);
+	alrm_data[3] = bin2bcd(alrm->time.tm_mday);
+	alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);
+	alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);
+
+	ret = regmap_bulk_write(rk808->regmap, RK808_ALARM_SECONDS_REG,
+				alrm_data, NUM_ALARM_REGS);
+	if (ret) {
+		dev_err(dev, "Failed to bulk write: %d\n", ret);
+		return ret;
+	}
+	if (alrm->enabled) {
+		ret = rk808_rtc_start_alarm(rk808_rtc);
+		if (ret) {
+			dev_err(dev, "Failed to start alarm: %d\n", ret);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static int rk808_rtc_alarm_irq_enable(struct device *dev,
+				      unsigned int enabled)
+{
+	struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
+
+	if (enabled)
+		return rk808_rtc_start_alarm(rk808_rtc);
+
+	return rk808_rtc_stop_alarm(rk808_rtc);
+}
+
+/*
+ * We will just handle setting the frequency and make use the framework for
+ * reading the periodic interupts.
+ *
+ * @freq: Current periodic IRQ freq:
+ * bit 0: every second
+ * bit 1: every minute
+ * bit 2: every hour
+ * bit 3: every day
+ */
+static irqreturn_t rk808_alarm_irq(int irq, void *data)
+{
+	struct rk808_rtc *rk808_rtc = data;
+	struct rk808 *rk808 = rk808_rtc->rk808;
+	struct i2c_client *client = rk808->i2c;
+	int ret;
+
+	ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
+			   RTC_STATUS_MASK);
+	if (ret) {
+		dev_err(&client->dev,
+			"%s:Failed to update RTC status: %d\n", __func__, ret);
+		return ret;
+	}
+
+	rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);
+	dev_dbg(&client->dev,
+		 "%s:irq=%d\n", __func__, irq);
+	return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops rk808_rtc_ops = {
+	.read_time = rk808_rtc_readtime,
+	.set_time = rk808_rtc_set_time,
+	.read_alarm = rk808_rtc_readalarm,
+	.set_alarm = rk808_rtc_setalarm,
+	.alarm_irq_enable = rk808_rtc_alarm_irq_enable,
+};
+
+#ifdef CONFIG_PM_SLEEP
+/* Turn off the alarm if it should not be a wake source. */
+static int rk808_rtc_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(rk808_rtc->irq);
+
+	return 0;
+}
+
+/* Enable the alarm if it should be enabled (in case it was disabled to
+ * prevent use as a wake source).
+ */
+static int rk808_rtc_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(rk808_rtc->irq);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,
+	rk808_rtc_suspend, rk808_rtc_resume);
+
+static int rk808_rtc_probe(struct platform_device *pdev)
+{
+	struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
+	struct rk808_rtc *rk808_rtc;
+	struct rtc_time tm;
+	int ret;
+
+	rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
+	if (rk808_rtc == NULL)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, rk808_rtc);
+	rk808_rtc->rk808 = rk808;
+
+	/* start rtc running by default, and use shadowed timer. */
+	ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
+				 BIT_RTC_CTRL_REG_STOP_RTC_M |
+				 BIT_RTC_CTRL_REG_RTC_READSEL_M,
+				 BIT_RTC_CTRL_REG_RTC_READSEL_M);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Failed to update RTC control: %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
+			   RTC_STATUS_MASK);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Failed to write RTC status: %d\n", ret);
+			return ret;
+	}
+
+	/* set init time */
+	ret = rk808_rtc_readtime(&pdev->dev, &tm);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to read RTC time\n");
+		return ret;
+	}
+	ret = rtc_valid_tm(&tm);
+	if (ret)
+		dev_warn(&pdev->dev, "invalid date/time\n");
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	rk808_rtc->rtc = devm_rtc_device_register(&pdev->dev, "rk808-rtc",
+						  &rk808_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rk808_rtc->rtc)) {
+		ret = PTR_ERR(rk808_rtc->rtc);
+		return ret;
+	}
+
+	rk808_rtc->irq = platform_get_irq(pdev, 0);
+	if (rk808_rtc->irq < 0) {
+		if (rk808_rtc->irq != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Wake up is not possible as irq = %d\n",
+				rk808_rtc->irq);
+		return rk808_rtc->irq;
+	}
+
+	/* request alarm irq of rk808 */
+	ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,
+					rk808_alarm_irq, 0,
+					"RTC alarm", rk808_rtc);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
+			rk808_rtc->irq, ret);
+	}
+
+	return ret;
+}
+
+static struct platform_driver rk808_rtc_driver = {
+	.probe = rk808_rtc_probe,
+	.driver = {
+		.name = "rk808-rtc",
+		.pm = &rk808_rtc_pm_ops,
+	},
+};
+
+module_platform_driver(rk808_rtc_driver);
+
+MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
+MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
+MODULE_AUTHOR("Zhang Qing <zhangqing@rock-chips.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rk808-rtc");