[PATCH v2] rtc: Add Epson RX8010SJ RTC driver
From: Akshay Bhat
Date: Thu Dec 03 2015 - 14:41:58 EST
This driver supports the following functions:
- reading and setting time
- alarms when connected to an IRQ
- reading and clearing the voltage low flags
Datasheet:
http://www.epsondevice.com/docs/qd/en/DownloadServlet?id=ID000956
Signed-off-by: Akshay Bhat <akshay.bhat@xxxxxxxxxxx>
---
Changes in v2:
- Address comments from Alexandre Belloni
- Update copyright info
- Use i2c_smbus_read_byte_data/i2c_smbus_read_i2c_block_data directly
- Use ffs for wday instead of bcd2bin
- Fixes from checkpatch --strict
- Limit date range to 2000 to 2100
- Fix incorrect write to RX8010_WDAY
- Do not clear VLF flag on power up
drivers/rtc/Kconfig | 10 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-rx8010.c | 523 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 534 insertions(+)
create mode 100644 drivers/rtc/rtc-rx8010.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2a52424..376322f 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -558,6 +558,16 @@ config RTC_DRV_FM3130
This driver can also be built as a module. If so the module
will be called rtc-fm3130.
+config RTC_DRV_RX8010
+ tristate "Epson RX8010SJ"
+ depends on I2C
+ help
+ If you say yes here you get support for the Epson RX8010SJ RTC
+ chip.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-rx8010.
+
config RTC_DRV_RX8581
tristate "Epson RX-8581"
help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 231f764..62d61b2 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -128,6 +128,7 @@ obj-$(CONFIG_RTC_DRV_RS5C372) += rtc-rs5c372.o
obj-$(CONFIG_RTC_DRV_RV3029C2) += rtc-rv3029c2.o
obj-$(CONFIG_RTC_DRV_RV8803) += rtc-rv8803.o
obj-$(CONFIG_RTC_DRV_RX4581) += rtc-rx4581.o
+obj-$(CONFIG_RTC_DRV_RX8010) += rtc-rx8010.o
obj-$(CONFIG_RTC_DRV_RX8025) += rtc-rx8025.o
obj-$(CONFIG_RTC_DRV_RX8581) += rtc-rx8581.o
obj-$(CONFIG_RTC_DRV_S35390A) += rtc-s35390a.o
diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c
new file mode 100644
index 0000000..772d221
--- /dev/null
+++ b/drivers/rtc/rtc-rx8010.c
@@ -0,0 +1,523 @@
+/*
+ * Driver for the Epson RTC module RX-8010 SJ
+ *
+ * Copyright(C) Timesys Corporation 2015
+ * Copyright(C) General Electric Company 2015
+ *
+ * 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/bcd.h>
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+
+#define RX8010_SEC 0x10
+#define RX8010_MIN 0x11
+#define RX8010_HOUR 0x12
+#define RX8010_WDAY 0x13
+#define RX8010_MDAY 0x14
+#define RX8010_MONTH 0x15
+#define RX8010_YEAR 0x16
+#define RX8010_YEAR 0x16
+#define RX8010_RESV17 0x17
+#define RX8010_ALMIN 0x18
+#define RX8010_ALHOUR 0x19
+#define RX8010_ALWDAY 0x1A
+#define RX8010_TCOUNT0 0x1B
+#define RX8010_TCOUNT1 0x1C
+#define RX8010_EXT 0x1D
+#define RX8010_FLAG 0x1E
+#define RX8010_CTRL 0x1F
+/* 0x20 to 0x2F are user registers */
+#define RX8010_RESV30 0x30
+#define RX8010_RESV31 0x32
+#define RX8010_IRQ 0x32
+
+#define RX8010_EXT_WADA BIT(3)
+
+#define RX8010_FLAG_VLF BIT(1)
+#define RX8010_FLAG_AF BIT(3)
+#define RX8010_FLAG_TF BIT(4)
+#define RX8010_FLAG_UF BIT(5)
+
+#define RX8010_CTRL_AIE BIT(3)
+#define RX8010_CTRL_UIE BIT(5)
+#define RX8010_CTRL_STOP BIT(6)
+#define RX8010_CTRL_TEST BIT(7)
+
+#define RX8010_ALARM_AE BIT(7)
+
+static const struct i2c_device_id rx8010_id[] = {
+ { "rx8010", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, rx8010_id);
+
+struct rx8010_data {
+ struct i2c_client *client;
+ struct rtc_device *rtc;
+ u8 ctrlreg;
+ spinlock_t flags_lock;
+};
+
+static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
+{
+ struct i2c_client *client = dev_id;
+ struct rx8010_data *rx8010 = i2c_get_clientdata(client);
+ int flagreg;
+
+ spin_lock(&rx8010->flags_lock);
+
+ flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
+
+ if (flagreg <= 0) {
+ spin_unlock(&rx8010->flags_lock);
+ return IRQ_NONE;
+ }
+
+ if (flagreg & RX8010_FLAG_VLF)
+ dev_warn(&client->dev, "Frequency stop detected\n");
+
+ if (flagreg & RX8010_FLAG_TF) {
+ flagreg &= ~RX8010_FLAG_TF;
+ rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
+ }
+
+ if (flagreg & RX8010_FLAG_AF) {
+ flagreg &= ~RX8010_FLAG_AF;
+ rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
+ }
+
+ if (flagreg & RX8010_FLAG_UF) {
+ flagreg &= ~RX8010_FLAG_UF;
+ rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
+ }
+
+ i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
+
+ spin_unlock(&rx8010->flags_lock);
+ return IRQ_HANDLED;
+}
+
+static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
+{
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ u8 date[7];
+ int flagreg;
+ int err;
+
+ flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
+ if (flagreg < 0)
+ return flagreg;
+
+ if (flagreg & RX8010_FLAG_VLF) {
+ dev_warn(dev, "Frequency stop detected\n");
+ return -EINVAL;
+ }
+
+ err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,
+ 7, date);
+ if (err != 7)
+ return err < 0 ? err : -EIO;
+
+ dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
+ dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
+ dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
+ dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
+ dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
+ dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
+ dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);
+
+ return rtc_valid_tm(dt);
+}
+
+static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
+{
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ u8 date[7];
+ int ctrl, flagreg;
+ int ret;
+ unsigned long irqflags;
+
+ if ((dt->tm_year < 100) || (dt->tm_year > 199))
+ return -EINVAL;
+
+ /* set STOP bit before changing clock/calendar */
+ ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
+ if (ctrl < 0)
+ return ctrl;
+ rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
+ ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (ret < 0)
+ return ret;
+
+ date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
+ date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
+ date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
+ date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
+ date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
+ date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
+ date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
+
+ ret = i2c_smbus_write_i2c_block_data(rx8010->client,
+ RX8010_SEC, 7, date);
+ if (ret < 0)
+ return ret;
+
+ /* clear STOP bit after changing clock/calendar */
+ ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
+ if (ctrl < 0)
+ return ctrl;
+ rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
+ ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (ret < 0)
+ return ret;
+
+ spin_lock_irqsave(&rx8010->flags_lock, irqflags);
+
+ flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
+ if (flagreg < 0) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return flagreg;
+ }
+
+ if (flagreg & RX8010_FLAG_VLF)
+ ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
+ flagreg & ~RX8010_FLAG_VLF);
+
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+
+ return 0;
+}
+
+static int rx8010_init_client(struct i2c_client *client)
+{
+ struct rx8010_data *rx8010 = i2c_get_clientdata(client);
+ u8 ctrl[2];
+ int need_clear = 0, err = 0;
+
+ /* Initialize reserved registers as specified in datasheet */
+ err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
+ if (err < 0)
+ return err;
+
+ err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
+ if (err < 0)
+ return err;
+
+ err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
+ if (err < 0)
+ return err;
+
+ err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
+ if (err < 0)
+ return err;
+
+ err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG,
+ 2, ctrl);
+ if (err != 2)
+ return err < 0 ? err : -EIO;
+
+ if (ctrl[0] & RX8010_FLAG_VLF)
+ dev_warn(&client->dev, "Frequency stop was detected\n");
+
+ if (ctrl[0] & RX8010_FLAG_AF) {
+ dev_warn(&client->dev, "Alarm was detected\n");
+ need_clear = 1;
+ }
+
+ if (ctrl[0] & RX8010_FLAG_TF)
+ need_clear = 1;
+
+ if (ctrl[0] & RX8010_FLAG_UF)
+ need_clear = 1;
+
+ if (need_clear) {
+ ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
+ err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]);
+ if (err < 0)
+ return err;
+ }
+
+ rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);
+
+ return err;
+}
+
+static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ struct i2c_client *client = rx8010->client;
+ u8 alarmvals[3];
+ int flagreg;
+ int err;
+
+ err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);
+ if (err != 3)
+ return err < 0 ? err : -EIO;
+
+ flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
+ if (flagreg < 0)
+ return flagreg;
+
+ t->time.tm_sec = 0;
+ t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
+ t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
+
+ if (alarmvals[2] & RX8010_ALARM_AE)
+ t->time.tm_mday = -1;
+ else
+ t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
+
+ t->time.tm_wday = -1;
+ t->time.tm_mon = -1;
+ t->time.tm_year = -1;
+
+ t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
+ t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
+
+ return err;
+}
+
+static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ u8 alarmvals[3];
+ int extreg, flagreg;
+ int err;
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&rx8010->flags_lock, irqflags);
+ flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
+ if (flagreg < 0) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return flagreg;
+ }
+
+ if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
+ rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (err < 0) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return err;
+ }
+ }
+
+ flagreg &= ~RX8010_FLAG_AF;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ if (err < 0)
+ return err;
+
+ alarmvals[0] = bin2bcd(t->time.tm_min);
+ alarmvals[1] = bin2bcd(t->time.tm_hour);
+ alarmvals[2] = bin2bcd(t->time.tm_mday);
+
+ err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
+ 2, alarmvals);
+ if (err < 0)
+ return err;
+
+ extreg = i2c_smbus_read_byte_data(client, RX8010_EXT);
+ if (extreg < 0)
+ return extreg;
+
+ extreg |= RX8010_EXT_WADA;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
+ if (err < 0)
+ return err;
+
+ if (alarmvals[2] == 0)
+ alarmvals[2] |= RX8010_ALARM_AE;
+
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
+ alarmvals[2]);
+ if (err < 0)
+ return err;
+
+ if (t->enabled) {
+ if (rx8010->rtc->uie_rtctimer.enabled)
+ rx8010->ctrlreg |= RX8010_CTRL_UIE;
+ if (rx8010->rtc->aie_timer.enabled)
+ rx8010->ctrlreg |=
+ (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+
+static int rx8010_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ int flagreg;
+ u8 ctrl;
+ int err;
+
+ ctrl = rx8010->ctrlreg;
+
+ if (enabled) {
+ if (rx8010->rtc->uie_rtctimer.enabled)
+ ctrl |= RX8010_CTRL_UIE;
+ if (rx8010->rtc->aie_timer.enabled)
+ ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
+ } else {
+ if (!rx8010->rtc->uie_rtctimer.enabled)
+ ctrl &= ~RX8010_CTRL_UIE;
+ if (!rx8010->rtc->aie_timer.enabled)
+ ctrl &= ~RX8010_CTRL_AIE;
+ }
+
+ flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
+ if (flagreg < 0)
+ return flagreg;
+
+ flagreg &= ~RX8010_FLAG_AF;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
+ if (err < 0)
+ return err;
+
+ if (ctrl != rx8010->ctrlreg) {
+ rx8010->ctrlreg = ctrl;
+ err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
+ rx8010->ctrlreg);
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+
+static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8010_data *rx8010 = dev_get_drvdata(dev);
+ int ret, tmp;
+ int flagreg;
+ unsigned long irqflags;
+
+ switch (cmd) {
+ case RTC_VL_READ:
+ flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
+ if (flagreg < 0)
+ return flagreg;
+
+ tmp = !!(flagreg & RX8010_FLAG_VLF);
+ if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
+ return -EFAULT;
+
+ return 0;
+
+ case RTC_VL_CLR:
+ spin_lock_irqsave(&rx8010->flags_lock, irqflags);
+ flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
+ if (flagreg < 0) {
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ return flagreg;
+ }
+
+ flagreg &= ~RX8010_FLAG_VLF;
+ ret = i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
+ spin_unlock_irqrestore(&rx8010->flags_lock, irqflags);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+static struct rtc_class_ops rx8010_rtc_ops = {
+ .read_time = rx8010_get_time,
+ .set_time = rx8010_set_time,
+ .ioctl = rx8010_ioctl,
+};
+
+static int rx8010_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ struct rx8010_data *rx8010;
+ int err = 0;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
+ | I2C_FUNC_SMBUS_I2C_BLOCK)) {
+ dev_err(&adapter->dev, "doesn't support required functionality\n");
+ return -EIO;
+ }
+
+ rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
+ GFP_KERNEL);
+ if (!rx8010)
+ return -ENOMEM;
+
+ rx8010->client = client;
+ i2c_set_clientdata(client, rx8010);
+
+ spin_lock_init(&rx8010->flags_lock);
+
+ err = rx8010_init_client(client);
+ if (err)
+ return err;
+
+ if (client->irq > 0) {
+ dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
+ err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+ rx8010_irq_1_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "rx8010", client);
+
+ if (err) {
+ dev_err(&client->dev, "unable to request IRQ\n");
+ client->irq = 0;
+ } else {
+ rx8010_rtc_ops.read_alarm = rx8010_read_alarm;
+ rx8010_rtc_ops.set_alarm = rx8010_set_alarm;
+ rx8010_rtc_ops.alarm_irq_enable = rx8010_alarm_irq_enable;
+ }
+ }
+
+ rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
+ &rx8010_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(rx8010->rtc)) {
+ dev_err(&client->dev, "unable to register the class device\n");
+ return PTR_ERR(rx8010->rtc);
+ }
+
+ rx8010->rtc->max_user_freq = 1;
+
+ return err;
+}
+
+static struct i2c_driver rx8010_driver = {
+ .driver = {
+ .name = "rtc-rx8010",
+ },
+ .probe = rx8010_probe,
+ .id_table = rx8010_id,
+};
+
+module_i2c_driver(rx8010_driver);
+
+MODULE_AUTHOR("Akshay Bhat <akshay.bhat@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
+MODULE_LICENSE("GPL v2");
--
2.6.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/