--- /dev/null
+/*
+ * Micro Crystal RV-3029C2 rtc class driver
+ *
+ * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
+ *
+ * based on previously existing rtc class drivers
+ *
+ * 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.
+ *
+ * NOTE: Currently this driver only supports the bare minimum for read
+ * and write the RTC and alarms. The extra features provided by this chip
+ * (trickle charger, eeprom, T° compensation) are unavailable.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+
+/* Register map */
+/* control section */
+#define RV3029C2_ONOFF_CTRL 0x00
+#define RV3029C2_IRQ_CTRL 0x01
+#define RV3029C2_IRQ_CTRL_AIE (1 << 0)
+#define RV3029C2_IRQ_FLAGS 0x02
+#define RV3029C2_IRQ_FLAGS_AF (1 << 0)
+#define RV3029C2_STATUS 0x03
+#define RV3029C2_STATUS_VLOW1 (1 << 2)
+#define RV3029C2_STATUS_VLOW2 (1 << 3)
+#define RV3029C2_STATUS_SR (1 << 4)
+#define RV3029C2_STATUS_PON (1 << 5)
+#define RV3029C2_STATUS_EEBUSY (1 << 7)
+#define RV3029C2_RST_CTRL 0x04
+#define RV3029C2_CONTROL_SECTION_LEN 0x05
+
+/* watch section */
+#define RV3029C2_W_SEC 0x08
+#define RV3029C2_W_MINUTES 0x09
+#define RV3029C2_W_HOURS 0x0A
+#define RV3029C2_REG_HR_12_24 (1<<6) /* 24h/12h mode */
+#define RV3029C2_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */
+#define RV3029C2_W_DATE 0x0B
+#define RV3029C2_W_DAYS 0x0C
+#define RV3029C2_W_MONTHS 0x0D
+#define RV3029C2_W_YEARS 0x0E
+#define RV3029C2_WATCH_SECTION_LEN 0x07
+
+/* alarm section */
+#define RV3029C2_A_SC 0x10
+#define RV3029C2_A_MN 0x11
+#define RV3029C2_A_HR 0x12
+#define RV3029C2_A_DT 0x13
+#define RV3029C2_A_DW 0x14
+#define RV3029C2_A_MO 0x15
+#define RV3029C2_A_YR 0x16
+#define RV3029C2_ALARM_SECTION_LEN 0x07
+
+/* timer section */
+#define RV3029C2_TIMER_LOW 0x18
+#define RV3029C2_TIMER_HIGH 0x19
+
+/* temperature section */
+#define RV3029C2_TEMP_PAGE 0x20
+
+/* eeprom data section */
+#define RV3029C2_E2P_EEDATA1 0x28
+#define RV3029C2_E2P_EEDATA2 0x29
+
+/* eeprom control section */
+#define RV3029C2_CONTROL_E2P_EECTRL 0x30
+#define RV3029C2_TRICKLE_1K (1<<0) /* 1K resistance */
+#define RV3029C2_TRICKLE_5K (1<<1) /* 5K resistance */
+#define RV3029C2_TRICKLE_20K (1<<2) /* 20K resistance */
+#define RV3029C2_TRICKLE_80K (1<<3) /* 80K resistance */
+#define RV3029C2_CONTROL_E2P_XTALOFFSET 0x31
+#define RV3029C2_CONTROL_E2P_QCOEF 0x32
+#define RV3029C2_CONTROL_E2P_TURNOVER 0x33
+
+/* user ram section */
+#define RV3029C2_USR1_RAM_PAGE 0x38
+#define RV3029C2_USR1_SECTION_LEN 0x04
+#define RV3029C2_USR2_RAM_PAGE 0x3C
+#define RV3029C2_USR2_SECTION_LEN 0x04
+
+static int
+rv3029c2_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf,
+ unsigned len)
+{
+ int ret;
+
+ if ((reg > RV3029C2_USR1_RAM_PAGE + 7) ||
+ (reg + len > RV3029C2_USR1_RAM_PAGE + 8))
+ return -EINVAL;
+
+ ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
+ if (ret < 0)
+ return ret;
+ if (ret < len)
+ return -EIO;
+ return 0;
+}
+
+static int
+rv3029c2_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[],
+ unsigned len)
+{
+ if ((reg > RV3029C2_USR1_RAM_PAGE + 7) ||
+ (reg + len > RV3029C2_USR1_RAM_PAGE + 8))
+ return -EINVAL;
+
+ return i2c_smbus_write_i2c_block_data(client, reg, len, buf);
+}
+
+static int
+rv3029c2_i2c_get_sr(struct i2c_client *client, u8 *buf)
+{
+ int ret = rv3029c2_i2c_read_regs(client, RV3029C2_STATUS, buf, 1);
+
+ if (ret < 0)
+ return -EIO;
+ dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
+ return 0;
+}
+
+static int
+rv3029c2_i2c_set_sr(struct i2c_client *client, u8 val)
+{
+ u8 buf[1];
+ int sr;
+
+ buf[0] = val;
+ sr = rv3029c2_i2c_write_regs(client, RV3029C2_STATUS, buf, 1);
+ dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
+ if (sr < 0)
+ return -EIO;
+ return 0;
+}
+
+static int
+rv3029c2_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
+{
+ u8 buf[1];
+ int ret;
+ u8 regs[RV3029C2_WATCH_SECTION_LEN] = { 0, };
+
+ ret = rv3029c2_i2c_get_sr(client, buf);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return -EIO;
+ }
+
+ ret = rv3029c2_i2c_read_regs(client, RV3029C2_W_SEC , regs,
+ RV3029C2_WATCH_SECTION_LEN);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reading RTC section failed\n",
+ __func__);
+ return ret;
+ }
+
+ tm->tm_sec = bcd2bin(regs[RV3029C2_W_SEC-RV3029C2_W_SEC]);
+ tm->tm_min = bcd2bin(regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC]);
+
+ /* HR field has a more complex interpretation */
+ {
+ const u8 _hr = regs[RV3029C2_W_HOURS-RV3029C2_W_SEC];
+ if (_hr & RV3029C2_REG_HR_12_24) {
+ /* 12h format */
+ tm->tm_hour = bcd2bin(_hr & 0x1f);
+ if (_hr & RV3029C2_REG_HR_PM) /* PM flag set */
+ tm->tm_hour += 12;
+ } else /* 24h format */
+ tm->tm_hour = bcd2bin(_hr & 0x3f);
+ }
+
+ tm->tm_mday = bcd2bin(regs[RV3029C2_W_DATE-RV3029C2_W_SEC]);
+ tm->tm_mon = bcd2bin(regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC]) - 1;
+ tm->tm_year = bcd2bin(regs[RV3029C2_W_YEARS-RV3029C2_W_SEC]) + 100;
+ tm->tm_wday = bcd2bin(regs[RV3029C2_W_DAYS-RV3029C2_W_SEC]) - 1;
+
+ return 0;
+}
+
+static int rv3029c2_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ return rv3029c2_i2c_read_time(to_i2c_client(dev), tm);
+}
+
+static int
+rv3029c2_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
+{
+ struct rtc_time *const tm = &alarm->time;
+ int ret;
+ u8 regs[8];
+
+ ret = rv3029c2_i2c_get_sr(client, regs);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return -EIO;
+ }
+
+ ret = rv3029c2_i2c_read_regs(client, RV3029C2_A_SC, regs,
+ RV3029C2_ALARM_SECTION_LEN);
+
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reading alarm section failed\n",
+ __func__);
+ return ret;
+ }
+
+ tm->tm_sec = bcd2bin(regs[RV3029C2_A_SC-RV3029C2_A_SC] & 0x7f);
+ tm->tm_min = bcd2bin(regs[RV3029C2_A_MN-RV3029C2_A_SC] & 0x7f);
+ tm->tm_hour = bcd2bin(regs[RV3029C2_A_HR-RV3029C2_A_SC] & 0x3f);
+ tm->tm_mday = bcd2bin(regs[RV3029C2_A_DT-RV3029C2_A_SC] & 0x3f);
+ tm->tm_mon = bcd2bin(regs[RV3029C2_A_MO-RV3029C2_A_SC] & 0x1f) - 1;
+ tm->tm_year = bcd2bin(regs[RV3029C2_A_YR-RV3029C2_A_SC] & 0x7f) + 100;
+ tm->tm_wday = bcd2bin(regs[RV3029C2_A_DW-RV3029C2_A_SC] & 0x07) - 1;
+
+ return 0;
+}
+
+static int
+rv3029c2_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ return rv3029c2_i2c_read_alarm(to_i2c_client(dev), alarm);
+}
+
+static int rv3029c2_rtc_i2c_alarm_set_irq(struct i2c_client *client,
+ int enable)
+{
+ int ret;
+ u8 buf[1];
+
+ /* enable AIE irq */
+ ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_CTRL, buf, 1);
+ if (ret < 0) {
+ dev_err(&client->dev, "can't read INT reg\n");
+ return ret;
+ }
+ if (enable)
+ buf[0] |= RV3029C2_IRQ_CTRL_AIE;
+ else
+ buf[0] &= ~RV3029C2_IRQ_CTRL_AIE;
+
+ ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_CTRL, buf, 1);
+ if (ret < 0) {
+ dev_err(&client->dev, "can't set INT reg\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int rv3029c2_rtc_i2c_set_alarm(struct i2c_client *client,
+ struct rtc_wkalrm *alarm)
+{
+ struct rtc_time *const tm = &alarm->time;
+ int ret;
+ u8 regs[8];
+
+ /*
+ * The clock has an 8 bit wide bcd-coded register (they never learn)
+ * for the year. tm_year is an offset from 1900 and we are interested
+ * in the 2000-2099 range, so any value less than 100 is invalid.
+ */
+ if (tm->tm_year < 100)
+ return -EINVAL;
+
+ ret = rv3029c2_i2c_get_sr(client, regs);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return -EIO;
+ }
+ regs[RV3029C2_A_SC-RV3029C2_A_SC] = bin2bcd(tm->tm_sec & 0x7f);
+ regs[RV3029C2_A_MN-RV3029C2_A_SC] = bin2bcd(tm->tm_min & 0x7f);
+ regs[RV3029C2_A_HR-RV3029C2_A_SC] = bin2bcd(tm->tm_hour & 0x3f);
+ regs[RV3029C2_A_DT-RV3029C2_A_SC] = bin2bcd(tm->tm_mday & 0x3f);
+ regs[RV3029C2_A_MO-RV3029C2_A_SC] = bin2bcd((tm->tm_mon & 0x1f) - 1);
+ regs[RV3029C2_A_DW-RV3029C2_A_SC] = bin2bcd((tm->tm_wday & 7) - 1);
+ regs[RV3029C2_A_YR-RV3029C2_A_SC] = bin2bcd((tm->tm_year & 0x7f) - 100);
+
+ ret = rv3029c2_i2c_write_regs(client, RV3029C2_A_SC, regs,
+ RV3029C2_ALARM_SECTION_LEN);
+ if (ret < 0)
+ return ret;
+
+ if (alarm->enabled) {
+ u8 buf[1];
+
+ /* clear AF flag */
+ ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_FLAGS,
+ buf, 1);
+ if (ret < 0) {
+ dev_err(&client->dev, "can't read alarm flag\n");
+ return ret;
+ }
+ buf[0] &= ~RV3029C2_IRQ_FLAGS_AF;
+ ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_FLAGS,
+ buf, 1);
+ if (ret < 0) {
+ dev_err(&client->dev, "can't set alarm flag\n");
+ return ret;
+ }
+ /* enable AIE irq */
+ ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 1);
+ if (ret)
+ return ret;
+
+ dev_dbg(&client->dev, "alarm IRQ armed\n");
+ } else {
+ /* disable AIE irq */
+ ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 0);
+ if (ret)
+ return ret;
+
+ dev_dbg(&client->dev, "alarm IRQ disabled\n");
+ }
+
+ return 0;
+}
+
+static int rv3029c2_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+ return rv3029c2_rtc_i2c_set_alarm(to_i2c_client(dev), alarm);
+}
+
+static int
+rv3029c2_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
+{
+ u8 regs[8];
+ int ret;
+
+ /*
+ * The clock has an 8 bit wide bcd-coded register (they never learn)
+ * for the year. tm_year is an offset from 1900 and we are interested
+ * in the 2000-2099 range, so any value less than 100 is invalid.
+ */
+ if (tm->tm_year < 100)
+ return -EINVAL;
+
+ regs[RV3029C2_W_SEC-RV3029C2_W_SEC] = bin2bcd(tm->tm_sec);
+ regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC] = bin2bcd(tm->tm_min);
+ regs[RV3029C2_W_HOURS-RV3029C2_W_SEC] = bin2bcd(tm->tm_hour);
+ regs[RV3029C2_W_DATE-RV3029C2_W_SEC] = bin2bcd(tm->tm_mday);
+ regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC] = bin2bcd(tm->tm_mon+1);
+ regs[RV3029C2_W_DAYS-RV3029C2_W_SEC] = bin2bcd((tm->tm_wday & 7)+1);
+ regs[RV3029C2_W_YEARS-RV3029C2_W_SEC] = bin2bcd(tm->tm_year - 100);
+
+ ret = rv3029c2_i2c_write_regs(client, RV3029C2_W_SEC, regs,
+ RV3029C2_WATCH_SECTION_LEN);
+ if (ret < 0)
+ return ret;
+
+ ret = rv3029c2_i2c_get_sr(client, regs);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return ret;
+ }
+ /* clear PON bit */
+ ret = rv3029c2_i2c_set_sr(client, (regs[0] & ~RV3029C2_STATUS_PON));
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reading SR failed\n", __func__);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int rv3029c2_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ return rv3029c2_i2c_set_time(to_i2c_client(dev), tm);
+}
+
+static const struct rtc_class_ops rv3029c2_rtc_ops = {
+ .read_time = rv3029c2_rtc_read_time,
+ .set_time = rv3029c2_rtc_set_time,
+ .read_alarm = rv3029c2_rtc_read_alarm,
+ .set_alarm = rv3029c2_rtc_set_alarm,
+};
+
+static struct i2c_device_id rv3029c2_id[] = {
+ { "rv3029c2", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, rv3029c2_id);
+
+static int rv3029c2_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct rtc_device *rtc;
+ int rc = 0;
+ u8 buf[1];
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_EMUL))
+ return -ENODEV;
+
+ rc = rv3029c2_i2c_get_sr(client, buf);
+ if (rc < 0) {
+ dev_err(&client->dev, "reading status failed\n");
+ return rc;
+ }
+
+ rtc = devm_rtc_device_register(&client->dev, client->name,
+ &rv3029c2_rtc_ops, THIS_MODULE);
+
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ i2c_set_clientdata(client, rtc);
+
+ return 0;
+}
+
+static struct i2c_driver rv3029c2_driver = {
+ .driver = {
+ .name = "rtc-rv3029c2",
+ },
+ .probe = rv3029c2_probe,
+ .id_table = rv3029c2_id,
+};
+
+module_i2c_driver(rv3029c2_driver);
+
+MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
+MODULE_DESCRIPTION("Micro Crystal RV3029C2 RTC driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff