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path: root/drivers/rtc/rtc-rx8025.c
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Diffstat (limited to 'drivers/rtc/rtc-rx8025.c')
-rw-r--r--drivers/rtc/rtc-rx8025.c591
1 files changed, 591 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rx8025.c b/drivers/rtc/rtc-rx8025.c
new file mode 100644
index 000000000..dde86f3e2
--- /dev/null
+++ b/drivers/rtc/rtc-rx8025.c
@@ -0,0 +1,591 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Epson's RTC module RX-8025 SA/NB
+ *
+ * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
+ *
+ * Copyright (C) 2005 by Digi International Inc.
+ * All rights reserved.
+ *
+ * Modified by fengjh at rising.com.cn
+ * <lm-sensors@lm-sensors.org>
+ * 2006.11
+ *
+ * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
+ * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
+ * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
+ */
+#include <linux/bcd.h>
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+
+/* Register definitions */
+#define RX8025_REG_SEC 0x00
+#define RX8025_REG_MIN 0x01
+#define RX8025_REG_HOUR 0x02
+#define RX8025_REG_WDAY 0x03
+#define RX8025_REG_MDAY 0x04
+#define RX8025_REG_MONTH 0x05
+#define RX8025_REG_YEAR 0x06
+#define RX8025_REG_DIGOFF 0x07
+#define RX8025_REG_ALWMIN 0x08
+#define RX8025_REG_ALWHOUR 0x09
+#define RX8025_REG_ALWWDAY 0x0a
+#define RX8025_REG_ALDMIN 0x0b
+#define RX8025_REG_ALDHOUR 0x0c
+/* 0x0d is reserved */
+#define RX8025_REG_CTRL1 0x0e
+#define RX8025_REG_CTRL2 0x0f
+
+#define RX8025_BIT_CTRL1_CT (7 << 0)
+/* 1 Hz periodic level irq */
+#define RX8025_BIT_CTRL1_CT_1HZ 4
+#define RX8025_BIT_CTRL1_TEST BIT(3)
+#define RX8025_BIT_CTRL1_1224 BIT(5)
+#define RX8025_BIT_CTRL1_DALE BIT(6)
+#define RX8025_BIT_CTRL1_WALE BIT(7)
+
+#define RX8025_BIT_CTRL2_DAFG BIT(0)
+#define RX8025_BIT_CTRL2_WAFG BIT(1)
+#define RX8025_BIT_CTRL2_CTFG BIT(2)
+#define RX8025_BIT_CTRL2_PON BIT(4)
+#define RX8025_BIT_CTRL2_XST BIT(5)
+#define RX8025_BIT_CTRL2_VDET BIT(6)
+
+#define RX8035_BIT_HOUR_1224 BIT(7)
+
+/* Clock precision adjustment */
+#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
+#define RX8025_ADJ_DATA_MAX 62
+#define RX8025_ADJ_DATA_MIN -62
+
+enum rx_model {
+ model_rx_unknown,
+ model_rx_8025,
+ model_rx_8035,
+ model_last
+};
+
+static const struct i2c_device_id rx8025_id[] = {
+ { "rx8025", model_rx_8025 },
+ { "rx8035", model_rx_8035 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, rx8025_id);
+
+struct rx8025_data {
+ struct rtc_device *rtc;
+ enum rx_model model;
+ u8 ctrl1;
+ int is_24;
+};
+
+static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
+{
+ return i2c_smbus_read_byte_data(client, number << 4);
+}
+
+static int rx8025_read_regs(const struct i2c_client *client,
+ u8 number, u8 length, u8 *values)
+{
+ int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
+ values);
+ if (ret != length)
+ return ret < 0 ? ret : -EIO;
+
+ return 0;
+}
+
+static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
+ u8 value)
+{
+ return i2c_smbus_write_byte_data(client, number << 4, value);
+}
+
+static s32 rx8025_write_regs(const struct i2c_client *client,
+ u8 number, u8 length, const u8 *values)
+{
+ return i2c_smbus_write_i2c_block_data(client, number << 4,
+ length, values);
+}
+
+static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2)
+{
+ int xstp = ctrl2 & RX8025_BIT_CTRL2_XST;
+ /* XSTP bit has different polarity on RX-8025 vs RX-8035.
+ * RX-8025: 0 == oscillator stopped
+ * RX-8035: 1 == oscillator stopped
+ */
+
+ if (model == model_rx_8025)
+ xstp = !xstp;
+
+ return xstp;
+}
+
+static int rx8025_check_validity(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8025_data *drvdata = dev_get_drvdata(dev);
+ int ctrl2;
+ int xstp;
+
+ ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
+ if (ctrl2 < 0)
+ return ctrl2;
+
+ if (ctrl2 & RX8025_BIT_CTRL2_VDET)
+ dev_warn(dev, "power voltage drop detected\n");
+
+ if (ctrl2 & RX8025_BIT_CTRL2_PON) {
+ dev_warn(dev, "power-on reset detected, date is invalid\n");
+ return -EINVAL;
+ }
+
+ xstp = rx8025_is_osc_stopped(drvdata->model, ctrl2);
+ if (xstp) {
+ dev_warn(dev, "crystal stopped, date is invalid\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int rx8025_reset_validity(struct i2c_client *client)
+{
+ struct rx8025_data *drvdata = i2c_get_clientdata(client);
+ int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
+
+ if (ctrl2 < 0)
+ return ctrl2;
+
+ ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);
+
+ if (drvdata->model == model_rx_8025)
+ ctrl2 |= RX8025_BIT_CTRL2_XST;
+ else
+ ctrl2 &= ~(RX8025_BIT_CTRL2_XST);
+
+ return rx8025_write_reg(client, RX8025_REG_CTRL2,
+ ctrl2);
+}
+
+static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
+{
+ struct i2c_client *client = dev_id;
+ struct rx8025_data *rx8025 = i2c_get_clientdata(client);
+ int status, xstp;
+
+ rtc_lock(rx8025->rtc);
+ status = rx8025_read_reg(client, RX8025_REG_CTRL2);
+ if (status < 0)
+ goto out;
+
+ xstp = rx8025_is_osc_stopped(rx8025->model, status);
+ if (xstp)
+ dev_warn(&client->dev, "Oscillation stop was detected,"
+ "you may have to readjust the clock\n");
+
+ if (status & RX8025_BIT_CTRL2_CTFG) {
+ /* periodic */
+ status &= ~RX8025_BIT_CTRL2_CTFG;
+ rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
+ }
+
+ if (status & RX8025_BIT_CTRL2_DAFG) {
+ /* alarm */
+ status &= RX8025_BIT_CTRL2_DAFG;
+ if (rx8025_write_reg(client, RX8025_REG_CTRL1,
+ rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
+ goto out;
+ rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
+ }
+
+out:
+ rtc_unlock(rx8025->rtc);
+
+ return IRQ_HANDLED;
+}
+
+static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8025_data *rx8025 = dev_get_drvdata(dev);
+ u8 date[7];
+ int err;
+
+ err = rx8025_check_validity(dev);
+ if (err)
+ return err;
+
+ err = rx8025_read_regs(client, RX8025_REG_SEC, 7, date);
+ if (err)
+ return err;
+
+ dev_dbg(dev, "%s: read %7ph\n", __func__, date);
+
+ dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
+ dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
+ if (rx8025->is_24)
+ dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
+ else
+ dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
+ + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
+
+ dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
+ dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
+ dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
+
+ dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
+
+ return 0;
+}
+
+static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8025_data *rx8025 = dev_get_drvdata(dev);
+ u8 date[7];
+ int ret;
+
+ /*
+ * Here the read-only bits are written as "0". I'm not sure if that
+ * is sound.
+ */
+ date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
+ date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
+ if (rx8025->is_24)
+ date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
+ else
+ date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
+ | bin2bcd((dt->tm_hour + 11) % 12 + 1);
+
+ date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
+ date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
+ date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
+ date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
+
+ dev_dbg(dev, "%s: write %7ph\n", __func__, date);
+
+ ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date);
+ if (ret < 0)
+ return ret;
+
+ return rx8025_reset_validity(client);
+}
+
+static int rx8025_init_client(struct i2c_client *client)
+{
+ struct rx8025_data *rx8025 = i2c_get_clientdata(client);
+ u8 ctrl[2], ctrl2;
+ int need_clear = 0;
+ int hour_reg;
+ int err;
+
+ err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
+ if (err)
+ goto out;
+
+ /* Keep test bit zero ! */
+ rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
+
+ if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
+ dev_warn(&client->dev, "Alarm was detected\n");
+ need_clear = 1;
+ }
+
+ if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
+ need_clear = 1;
+
+ if (need_clear) {
+ ctrl2 = ctrl[1];
+ ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
+ RX8025_BIT_CTRL2_DAFG);
+
+ err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
+ }
+
+ if (rx8025->model == model_rx_8035) {
+ /* In RX-8035, 12/24 flag is in the hour register */
+ hour_reg = rx8025_read_reg(client, RX8025_REG_HOUR);
+ if (hour_reg < 0)
+ return hour_reg;
+ rx8025->is_24 = (hour_reg & RX8035_BIT_HOUR_1224);
+ } else {
+ rx8025->is_24 = (ctrl[1] & RX8025_BIT_CTRL1_1224);
+ }
+out:
+ return err;
+}
+
+/* Alarm support */
+static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8025_data *rx8025 = dev_get_drvdata(dev);
+ u8 ald[2];
+ int ctrl2, err;
+
+ err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
+ if (err)
+ return err;
+
+ ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
+ if (ctrl2 < 0)
+ return ctrl2;
+
+ dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
+ __func__, ald[0], ald[1], ctrl2);
+
+ /* Hardware alarms precision is 1 minute! */
+ t->time.tm_sec = 0;
+ t->time.tm_min = bcd2bin(ald[0] & 0x7f);
+ if (rx8025->is_24)
+ t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
+ else
+ t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
+ + (ald[1] & 0x20 ? 12 : 0);
+
+ dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
+ t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
+ t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
+
+ return err;
+}
+
+static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8025_data *rx8025 = dev_get_drvdata(dev);
+ u8 ald[2];
+ int err;
+
+ ald[0] = bin2bcd(t->time.tm_min);
+ if (rx8025->is_24)
+ ald[1] = bin2bcd(t->time.tm_hour);
+ else
+ ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
+ | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
+
+ dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
+
+ if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
+ rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
+ err = rx8025_write_reg(client, RX8025_REG_CTRL1,
+ rx8025->ctrl1);
+ if (err)
+ return err;
+ }
+ err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
+ if (err)
+ return err;
+
+ if (t->enabled) {
+ rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
+ err = rx8025_write_reg(client, RX8025_REG_CTRL1,
+ rx8025->ctrl1);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct rx8025_data *rx8025 = dev_get_drvdata(dev);
+ u8 ctrl1;
+ int err;
+
+ ctrl1 = rx8025->ctrl1;
+ if (enabled)
+ ctrl1 |= RX8025_BIT_CTRL1_DALE;
+ else
+ ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
+
+ if (ctrl1 != rx8025->ctrl1) {
+ rx8025->ctrl1 = ctrl1;
+ err = rx8025_write_reg(client, RX8025_REG_CTRL1,
+ rx8025->ctrl1);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+/*
+ * According to the RX8025 SA/NB application manual the frequency and
+ * temperature characteristics can be approximated using the following
+ * equation:
+ *
+ * df = a * (ut - t)**2
+ *
+ * df: Frequency deviation in any temperature
+ * a : Coefficient = (-35 +-5) * 10**-9
+ * ut: Ultimate temperature in degree = +25 +-5 degree
+ * t : Any temperature in degree
+ */
+static int rx8025_read_offset(struct device *dev, long *offset)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int digoff;
+
+ digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
+ if (digoff < 0)
+ return digoff;
+
+ *offset = digoff >= 64 ? digoff - 128 : digoff;
+ if (*offset > 0)
+ (*offset)--;
+ *offset *= RX8025_ADJ_RESOLUTION;
+
+ return 0;
+}
+
+static int rx8025_set_offset(struct device *dev, long offset)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ u8 digoff;
+
+ offset /= RX8025_ADJ_RESOLUTION;
+ if (offset > RX8025_ADJ_DATA_MAX)
+ offset = RX8025_ADJ_DATA_MAX;
+ else if (offset < RX8025_ADJ_DATA_MIN)
+ offset = RX8025_ADJ_DATA_MIN;
+ else if (offset > 0)
+ offset++;
+ else if (offset < 0)
+ offset += 128;
+ digoff = offset;
+
+ return rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
+}
+
+static const struct rtc_class_ops rx8025_rtc_ops = {
+ .read_time = rx8025_get_time,
+ .set_time = rx8025_set_time,
+ .read_alarm = rx8025_read_alarm,
+ .set_alarm = rx8025_set_alarm,
+ .alarm_irq_enable = rx8025_alarm_irq_enable,
+ .read_offset = rx8025_read_offset,
+ .set_offset = rx8025_set_offset,
+};
+
+static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ long adj;
+ int err;
+
+ dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
+ err = rx8025_read_offset(dev, &adj);
+ if (err)
+ return err;
+
+ return sprintf(buf, "%ld\n", -adj);
+}
+
+static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ long adj;
+ int err;
+
+ dev_warn_once(dev, "clock_adjust_ppb is deprecated, use offset\n");
+ if (kstrtol(buf, 10, &adj) != 0)
+ return -EINVAL;
+
+ err = rx8025_set_offset(dev, -adj);
+
+ return err ? err : count;
+}
+
+static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
+ rx8025_sysfs_show_clock_adjust,
+ rx8025_sysfs_store_clock_adjust);
+
+static struct attribute *rx8025_attrs[] = {
+ &dev_attr_clock_adjust_ppb.attr,
+ NULL
+};
+
+static const struct attribute_group rx8025_attr_group = {
+ .attrs = rx8025_attrs,
+};
+
+static int rx8025_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ struct rx8025_data *rx8025;
+ 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;
+ }
+
+ rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
+ if (!rx8025)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, rx8025);
+
+ if (id)
+ rx8025->model = id->driver_data;
+
+ err = rx8025_init_client(client);
+ if (err)
+ return err;
+
+ rx8025->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(rx8025->rtc))
+ return PTR_ERR(rx8025->rtc);
+
+ rx8025->rtc->ops = &rx8025_rtc_ops;
+ rx8025->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
+ rx8025->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+ if (client->irq > 0) {
+ dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
+ err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+ rx8025_handle_irq,
+ IRQF_ONESHOT,
+ "rx8025", client);
+ if (err)
+ clear_bit(RTC_FEATURE_ALARM, rx8025->rtc->features);
+ }
+
+ rx8025->rtc->max_user_freq = 1;
+
+ set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rx8025->rtc->features);
+ clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rx8025->rtc->features);
+
+ err = rtc_add_group(rx8025->rtc, &rx8025_attr_group);
+ if (err)
+ return err;
+
+ return devm_rtc_register_device(rx8025->rtc);
+}
+
+static struct i2c_driver rx8025_driver = {
+ .driver = {
+ .name = "rtc-rx8025",
+ },
+ .probe = rx8025_probe,
+ .id_table = rx8025_id,
+};
+
+module_i2c_driver(rx8025_driver);
+
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 09:46:54 +0000