[PATCH v2 5/5] rtc: rtc-rc5t619: add ricoh rc5t619 RTC driver

Andreas Kemnade
2019-10-31T21:39:31Z

Add an RTC driver for the RTC device on Ricoh MFD rc5t619,
which is implemented as a variant of rn5t618.

rtc-range output:
Testing 2000-02-28 23:59:59.
OK

Testing 2038-01-19 03:14:07.
OK

Testing 2069-12-31 23:59:59.
OK

Testing 2099-12-31 23:59:59.
KO RTC_RD_TIME returned 22 (line 138)

Testing 2100-02-28 23:59:59.
KO RTC_SET_TIME returned 34 (line 122)

Testing 2106-02-07 06:28:15.
KO RTC_SET_TIME returned 34 (line 122)

Testing 2262-04-11 23:47:16.
KO RTC_SET_TIME returned 34 (line 122)

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
Changes in v2:
- correct subject line
- reset pon flag not at probe but later
- initialize things only on pon
- 12h handling
- ranges
- style cleanup
- less magic values

drivers/rtc/Kconfig | 10 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-rc5t619.c | 488 ++++++++++++++++++++++++++++++++++++++
3 files changed, 499 insertions(+)
create mode 100644 drivers/rtc/rtc-rc5t619.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 1adf9f815652..b8e5bfa8efc6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -600,6 +600,16 @@ config RTC_DRV_RC5T583
This driver can also be built as a module. If so, the module
will be called rtc-rc5t583.

+config RTC_DRV_RC5T619
+ tristate "RICOH RC5T619 RTC driver"
+ depends on MFD_RN5T618
+ help
+ If you say yes here you get support for the RTC on the
+ RICOH RC5T619 chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-rc5t619.
+
config RTC_DRV_S35390A
tristate "Seiko Instruments S-35390A"
select BITREVERSE
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 4ac8f19fb631..7612912cdf00 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -137,6 +137,7 @@ obj-$(CONFIG_RTC_DRV_PXA) += rtc-pxa.o
obj-$(CONFIG_RTC_DRV_R7301) += rtc-r7301.o
obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o
obj-$(CONFIG_RTC_DRV_RC5T583) += rtc-rc5t583.o
+obj-$(CONFIG_RTC_DRV_RC5T619) += rtc-rc5t619.o
obj-$(CONFIG_RTC_DRV_RK808) += rtc-rk808.o
obj-$(CONFIG_RTC_DRV_RP5C01) += rtc-rp5c01.o
obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o
diff --git a/drivers/rtc/rtc-rc5t619.c b/drivers/rtc/rtc-rc5t619.c
new file mode 100644
index 000000000000..903bb9f9d96b
--- /dev/null
+++ b/drivers/rtc/rtc-rc5t619.c
@@ -0,0 +1,488 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * drivers/rtc/rtc-rc5t619.c
+ *
+ * Real time clock driver for RICOH RC5T619 power management chip.
+ *
+ * Copyright (C) 2019 Andreas Kemnade
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mfd/rn5t618.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/irqdomain.h>
+
+struct rc5t619_rtc {
+ int irq;
+ struct rtc_device *rtc;
+ struct rn5t618 *rn5t618;
+};
+
+#define CTRL1_ALARM_ENABLED 0x40
+#define CTRL1_24HR 0x20
+#define CTRL1_PERIODIC_MASK 0xf
+
+#define CTRL2_PON 0x10
+#define CTRL2_ALARM_STATUS 0x80
+#define CTRL2_CTFG 0x4
+#define CTRL2_CTC 0x1
+
+#define MONTH_CENTFLAG 0x80
+#define HOUR_PMFLAG 0x20
+#define MDAY_DAL_EXT 0x80
+
+static uint8_t rtc5t619_12hour_bcd2bin(uint8_t hour)
+{
+ if (hour & HOUR_PMFLAG) {
+ hour = bcd2bin(hour & ~HOUR_PMFLAG);
+ return hour == 12 ? 12 : 12 + hour;
+ }
+
+ hour = bcd2bin(hour);
+ return hour == 12 ? 0 : hour;
+}
+
+static uint8_t rtc5t619_12hour_bin2bcd(uint8_t hour)
+{
+ if (!hour)
+ return 0x12;
+
+ if (hour < 12)
+ return bin2bcd(hour);
+
+ if (hour == 12)
+ return 0x12 | HOUR_PMFLAG;
+
+ return bin2bcd(hour - 12) | HOUR_PMFLAG;
+}
+
+static int rc5t619_rtc_periodic_disable(struct device *dev)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+ int err;
+
+ /* disable function */
+ err = regmap_update_bits(rtc->rn5t618->regmap,
+ RN5T618_RTC_CTRL1, CTRL1_PERIODIC_MASK, 0);
+ if (err < 0)
+ return err;
+
+ /* clear alarm flag and CTFG */
+ err = regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2,
+ CTRL2_ALARM_STATUS | CTRL2_CTFG | CTRL2_CTC, 0);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+/* things to be done once after power on */
+static int rc5t619_rtc_pon_setup(struct device *dev)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+ int err;
+ unsigned int reg_data;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &reg_data);
+ if (err < 0)
+ return err;
+
+ /* clear VDET PON */
+ reg_data &= ~(CTRL2_PON | CTRL2_CTC | 0x4a); /* 0101-1011 */
+ reg_data |= 0x20; /* 0010-0000 */
+ err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2,
+ reg_data);
+ if (err < 0)
+ return err;
+
+ /* clearing RTC Adjust register */
+ err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_ADJUST, 0);
+ if (err)
+ return err;
+
+ return regmap_update_bits(rtc->rn5t618->regmap,
+ RN5T618_RTC_CTRL1,
+ CTRL1_24HR, CTRL1_24HR);
+}
+
+static int rc5t619_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+ u8 buff[7];
+ int err;
+ int cent_flag;
+ unsigned int ctrl1;
+ unsigned int ctrl2;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
+ if (err < 0)
+ return err;
+
+ if (ctrl2 & CTRL2_PON)
+ return -EINVAL;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
+ if (err < 0)
+ return err;
+
+ err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
+ buff, sizeof(buff));
+ if (err < 0)
+ return err;
+
+ if (buff[5] & MONTH_CENTFLAG)
+ cent_flag = 1;
+ else
+ cent_flag = 0;
+
+ tm->tm_sec = bcd2bin(buff[0]);
+ tm->tm_min = bcd2bin(buff[1]);
+
+ if (ctrl1 & CTRL1_24HR)
+ tm->tm_hour = bcd2bin(buff[2]);
+ else
+ tm->tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
+
+ tm->tm_wday = bcd2bin(buff[3]);
+ tm->tm_mday = bcd2bin(buff[4]);
+ tm->tm_mon = bcd2bin(buff[5] & 0x1f) - 1; /* back to system 0-11 */
+ tm->tm_year = bcd2bin(buff[6]) + 100 * cent_flag;
+
+ return 0;
+}
+
+static int rc5t619_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+ u8 buff[7];
+ int err;
+ int cent_flag;
+ unsigned int ctrl1;
+ unsigned int ctrl2;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
+ if (err < 0)
+ return err;
+
+ if (ctrl2 & CTRL2_PON)
+ rc5t619_rtc_pon_setup(dev);
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
+ if (err < 0)
+ return err;
+
+ if (tm->tm_year >= 100)
+ cent_flag = 1;
+ else
+ cent_flag = 0;
+
+ buff[0] = bin2bcd(tm->tm_sec);
+ buff[1] = bin2bcd(tm->tm_min);
+
+ if (ctrl1 & CTRL1_24HR)
+ buff[2] = bin2bcd(tm->tm_hour);
+ else
+ buff[2] = rtc5t619_12hour_bin2bcd(tm->tm_hour);
+
+ buff[3] = bin2bcd(tm->tm_wday);
+ buff[4] = bin2bcd(tm->tm_mday);
+ buff[5] = bin2bcd(tm->tm_mon + 1); /* system set 0-11 */
+ buff[6] = bin2bcd(tm->tm_year - cent_flag * 100);
+
+ if (cent_flag)
+ buff[5] |= MONTH_CENTFLAG;
+
+ err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
+ buff, sizeof(buff));
+ if (err < 0) {
+ dev_err(dev, "failed to program new time: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static int rc5t619_rtc_alarm_is_enabled(struct device *dev, uint8_t *enabled)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+ int err;
+ unsigned int reg_data;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &reg_data);
+ if (err)
+ return err;
+
+ if (reg_data & CTRL1_ALARM_ENABLED)
+ *enabled = 1;
+ else
+ *enabled = 0;
+
+ return err;
+}
+
+/* 0-disable, 1-enable */
+static int rc5t619_rtc_alarm_enable(struct device *dev, unsigned int enabled)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+
+ return regmap_update_bits(rtc->rn5t618->regmap,
+ RN5T618_RTC_CTRL1,
+ CTRL1_ALARM_ENABLED,
+ enabled ? CTRL1_ALARM_ENABLED : 0);
+}
+
+static int rc5t619_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+ u8 buff[6];
+ unsigned int buff_cent;
+ int err;
+ int cent_flag;
+ unsigned int ctrl1;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
+ if (err)
+ return err;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_MONTH, &buff_cent);
+ if (err < 0) {
+ dev_err(dev, "failed to read time: %d\n", err);
+ return err;
+ }
+
+ if (buff_cent & MONTH_CENTFLAG)
+ cent_flag = 1;
+ else
+ cent_flag = 0;
+
+ err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
+ buff, sizeof(buff));
+ if (err)
+ return err;
+
+
+ buff[3] = buff[3] & 0x3f;
+
+ alrm->time.tm_sec = bcd2bin(buff[0]);
+ alrm->time.tm_min = bcd2bin(buff[1]);
+
+ if (ctrl1 & CTRL1_24HR)
+ alrm->time.tm_hour = bcd2bin(buff[2]);
+ else
+ alrm->time.tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
+
+ alrm->time.tm_mday = bcd2bin(buff[3]);
+ alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
+ alrm->time.tm_year = bcd2bin(buff[5]) + 100 * cent_flag;
+ alrm->enabled = !!(ctrl1 & CTRL1_ALARM_ENABLED);
+ dev_dbg(dev, "read alarm: %ptR\n", &alrm->time);
+
+ return 0;
+}
+
+static int rc5t619_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+ u8 buff[6];
+ int err;
+ int cent_flag;
+ unsigned int ctrl1;
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
+ if (err)
+ return err;
+
+ err = rc5t619_rtc_alarm_enable(dev, 0);
+ if (err < 0)
+ return err;
+
+ if (rtc->irq == -1)
+ return -EINVAL;
+
+ if (alrm->enabled == 0)
+ return 0;
+
+ if (alrm->time.tm_year >= 100)
+ cent_flag = 1;
+ else
+ cent_flag = 0;
+
+ alrm->time.tm_mon += 1;
+ buff[0] = bin2bcd(alrm->time.tm_sec);
+ buff[1] = bin2bcd(alrm->time.tm_min);
+
+ if (ctrl1 & CTRL1_24HR)
+ buff[2] = bin2bcd(alrm->time.tm_hour);
+ else
+ buff[2] = rtc5t619_12hour_bin2bcd(alrm->time.tm_hour);
+
+ buff[3] = bin2bcd(alrm->time.tm_mday);
+ buff[4] = bin2bcd(alrm->time.tm_mon);
+ buff[5] = bin2bcd(alrm->time.tm_year - 100 * cent_flag);
+ buff[3] |= MDAY_DAL_EXT;
+
+ err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
+ buff, sizeof(buff));
+ if (err < 0)
+ return err;
+
+ return rc5t619_rtc_alarm_enable(dev, alrm->enabled);
+}
+
+static const struct rtc_class_ops rc5t619_rtc_ops = {
+ .read_time = rc5t619_rtc_read_time,
+ .set_time = rc5t619_rtc_set_time,
+ .set_alarm = rc5t619_rtc_set_alarm,
+ .read_alarm = rc5t619_rtc_read_alarm,
+ .alarm_irq_enable = rc5t619_rtc_alarm_enable,
+};
+
+static int rc5t619_rtc_alarm_flag_clr(struct device *dev)
+{
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+
+ /* clear alarm-D status bits.*/
+ return regmap_update_bits(rtc->rn5t618->regmap,
+ RN5T618_RTC_CTRL2,
+ CTRL2_ALARM_STATUS | CTRL2_CTC, 0);
+}
+
+static irqreturn_t rc5t619_rtc_irq(int irq, void *data)
+{
+ struct device *dev = data;
+ struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+
+ rc5t619_rtc_alarm_flag_clr(dev);
+
+ rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
+ return IRQ_HANDLED;
+}
+
+
+static int rc5t619_rtc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
+ struct rc5t619_rtc *rtc;
+ uint8_t alarm_flag;
+ unsigned int ctrl2;
+ int err;
+
+ rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL);
+ if (IS_ERR(rtc)) {
+ err = PTR_ERR(rtc);
+ return -ENOMEM;
+ }
+
+ rtc->rn5t618 = rn5t618;
+
+ dev_set_drvdata(dev, rtc);
+ rtc->irq = -1;
+
+ if (rn5t618->irq_data)
+ rtc->irq = regmap_irq_get_virq(rn5t618->irq_data,
+ RN5T618_IRQ_RTC);
+
+ if (rtc->irq < 0) {
+ dev_err(dev, "no irq specified, wakeup is disabled\n");
+ rtc->irq = -1;
+ }
+
+ err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
+ if (err < 0)
+ return err;
+
+ /* get interrupt flag */
+ err = rc5t619_rtc_alarm_is_enabled(dev, &alarm_flag);
+ if (err)
+ return err;
+
+ /* disable rtc periodic function */
+ err = rc5t619_rtc_periodic_disable(&pdev->dev);
+ if (err)
+ return err;
+
+ /* disable interrupt */
+ err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
+ if (err)
+ return err;
+
+ if (ctrl2 & CTRL2_PON) {
+ alarm_flag = 0;
+ err = rc5t619_rtc_alarm_flag_clr(&pdev->dev);
+ if (err)
+ return err;
+ }
+
+ rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
+
+ if (IS_ERR(rtc->rtc)) {
+ err = PTR_ERR(rtc->rtc);
+ dev_err(dev, "RTC device register: err %d\n", err);
+ return err;
+ }
+
+ rtc->rtc->ops = &rc5t619_rtc_ops;
+ rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
+ rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+ /* set interrupt and enable it */
+ if (rtc->irq != -1) {
+ device_init_wakeup(&pdev->dev, 1);
+
+ err = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
+ rc5t619_rtc_irq,
+ IRQF_ONESHOT,
+ "rtc-rc5t619",
+ &pdev->dev);
+ if (err < 0) {
+ dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq);
+ rtc->irq = -1;
+
+ err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
+ if (err)
+ return err;
+
+ } else {
+ /* enable wake */
+ enable_irq_wake(rtc->irq);
+ /* enable alarm_d */
+ err = rc5t619_rtc_alarm_enable(&pdev->dev, alarm_flag);
+ if (err) {
+ dev_err(&pdev->dev, "failed rtc setup\n");
+ return -EBUSY;
+ }
+ }
+ } else {
+ /* system don't want to using alarm interrupt, so close it */
+ err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
+ if (err) {
+ dev_err(&pdev->dev, "disable rtc alarm error\n");
+ return err;
+ }
+
+ dev_err(&pdev->dev, "ricoh61x interrupt is disabled\n");
+ }
+
+ return rtc_register_device(rtc->rtc);
+}
+
+static struct platform_driver rc5t619_rtc_driver = {
+ .driver = {
+ .name = "rc5t619-rtc",
+ },
+ .probe = rc5t619_rtc_probe,
+};
+
+module_platform_driver(rc5t619_rtc_driver);
+MODULE_ALIAS("platform:rc5t619-rtc");
+MODULE_DESCRIPTION("RICOH RC5T619 RTC driver");
+MODULE_LICENSE("GPL");
--
2.20.1