[PATCH v6 3/5] RTC: RK808: add RTC driver for RK808

Chris Zhong
2014-08-26T14:16:05Z

Adding RTC driver for supporting RTC device present inside RK808 PMIC.

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Zhang Qing <zhangqing@rock-chips.com>

---

Changes in v6:
Adviced by doug
- move RTC_READSEL setting into probe

Changes in v5:
- fixed a bug about set_time failed

Changes in v4:
- use &client->dev replace rk808->dev

Changes in v3: None
Changes in v2:
Adviced by javier.martinez
- Add a separate clock driver, rather than in RTC driver

drivers/rtc/Kconfig | 10 ++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-rk808.c | 412 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 423 insertions(+)
create mode 100644 drivers/rtc/rtc-rk808.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index a168e96..aeab9d9 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -288,6 +288,16 @@ config RTC_DRV_MAX77686
This driver can also be built as a module. If so, the module
will be called rtc-max77686.

+config RTC_DRV_RK808
+ tristate "Rockchip RK808 RTC"
+ depends on MFD_RK808
+ help
+ If you say yes here you will get support for the
+ RTC of RK808 PMIC.
+
+ This driver can also be built as a module. If so, the module
+ will be called rk808-rtc.
+
config RTC_DRV_RS5C372
tristate "Ricoh R2025S/D, RS5C372A/B, RV5C386, RV5C387A"
help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 56f061c..91fe4647 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_RTC_DRV_PUV3) += rtc-puv3.o
obj-$(CONFIG_RTC_DRV_PXA) += rtc-pxa.o
obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o
obj-$(CONFIG_RTC_DRV_RC5T583) += rtc-rc5t583.o
+obj-$(CONFIG_RTC_DRV_RK808) += rtc-rk808.o
obj-$(CONFIG_RTC_DRV_RP5C01) += rtc-rp5c01.o
obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o
obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o
diff --git a/drivers/rtc/rtc-rk808.c b/drivers/rtc/rtc-rk808.c
new file mode 100644
index 0000000..00cd997
--- /dev/null
+++ b/drivers/rtc/rtc-rk808.c
@@ -0,0 +1,412 @@
+/*
+ * RTC driver for Rockchip RK808
+ *
+ * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * 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)
+#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;
+
+ 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 0;
+}
+
+/* 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;
+ uint32_t rtc_ctl;
+ 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,rtc_ctl=0x%x\n", __func__, irq, rtc_ctl);
+ 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
+/* 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;
+}
+#else
+#define rk808_rtc_suspend NULL
+#define rk808_rtc_resume NULL
+#endif
+
+static const struct dev_pm_ops rk808_rtc_pm_ops = {
+ .suspend = rk808_rtc_suspend,
+ .resume = rk808_rtc_resume,
+ .poweroff = rk808_rtc_suspend,
+};
+
+/* 2012.1.1 12:00:00 Saturday */
+struct rtc_time tm_def = {
+ .tm_wday = 6,
+ .tm_year = 114,
+ .tm_mon = 0,
+ .tm_mday = 1,
+ .tm_hour = 12,
+ .tm_min = 0,
+ .tm_sec = 0,
+};
+
+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.
+ * RK808 has a shadowed register for saving a "frozen" RTC time.
+ * When user setting "RTC_READSEL" to 1, the time will save in this
+ * shadowed register. In this case, user read rtc time register,
+ * actually get the time of that moment. We need the real time,
+ * so clr this bit.
+ */
+ ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
+ BIT_RTC_CTRL_REG_STOP_RTC_M |
+ BIT_RTC_CTRL_REG_RTC_READSEL_M, 0);
+ 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 and init time\n");
+ rk808_rtc_set_time(&pdev->dev, &tm_def);
+ }
+
+ 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) {
+ dev_warn(&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,
+ IRQF_TRIGGER_LOW | IRQF_EARLY_RESUME,
+ "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 <zhanqging@rock-chips.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rk808-rtc");
--
1.7.9.5