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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/rtc/rtc-isl12022.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/rtc/rtc-isl12022.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-isl12022.c b/drivers/rtc/rtc-isl12022.c
new file mode 100644
index 000000000..ca677c426
--- /dev/null
+++ b/drivers/rtc/rtc-isl12022.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * An I2C driver for the Intersil ISL 12022
+ *
+ * Author: Roman Fietze <roman.fietze@telemotive.de>
+ *
+ * Based on the Philips PCF8563 RTC
+ * by Alessandro Zummo <a.zummo@towertech.it>.
+ */
+
+#include <linux/i2c.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+/* ISL register offsets */
+#define ISL12022_REG_SC 0x00
+#define ISL12022_REG_MN 0x01
+#define ISL12022_REG_HR 0x02
+#define ISL12022_REG_DT 0x03
+#define ISL12022_REG_MO 0x04
+#define ISL12022_REG_YR 0x05
+#define ISL12022_REG_DW 0x06
+
+#define ISL12022_REG_SR 0x07
+#define ISL12022_REG_INT 0x08
+
+/* ISL register bits */
+#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
+
+#define ISL12022_SR_LBAT85 (1 << 2)
+#define ISL12022_SR_LBAT75 (1 << 1)
+
+#define ISL12022_INT_WRTC (1 << 6)
+
+
+static struct i2c_driver isl12022_driver;
+
+struct isl12022 {
+ struct rtc_device *rtc;
+ struct regmap *regmap;
+};
+
+/*
+ * In the routines that deal directly with the isl12022 hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
+ */
+static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct isl12022 *isl12022 = dev_get_drvdata(dev);
+ struct regmap *regmap = isl12022->regmap;
+ uint8_t buf[ISL12022_REG_INT + 1];
+ int ret;
+
+ ret = regmap_bulk_read(regmap, ISL12022_REG_SC, buf, sizeof(buf));
+ if (ret)
+ return ret;
+
+ if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
+ dev_warn(dev,
+ "voltage dropped below %u%%, "
+ "date and time is not reliable.\n",
+ buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
+ }
+
+ dev_dbg(dev,
+ "%s: raw data is sec=%02x, min=%02x, hr=%02x, "
+ "mday=%02x, mon=%02x, year=%02x, wday=%02x, "
+ "sr=%02x, int=%02x",
+ __func__,
+ buf[ISL12022_REG_SC],
+ buf[ISL12022_REG_MN],
+ buf[ISL12022_REG_HR],
+ buf[ISL12022_REG_DT],
+ buf[ISL12022_REG_MO],
+ buf[ISL12022_REG_YR],
+ buf[ISL12022_REG_DW],
+ buf[ISL12022_REG_SR],
+ buf[ISL12022_REG_INT]);
+
+ tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
+ tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
+ tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
+ tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
+ tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
+ tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
+ tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
+
+ dev_dbg(dev, "%s: %ptR\n", __func__, tm);
+
+ return 0;
+}
+
+static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct isl12022 *isl12022 = dev_get_drvdata(dev);
+ struct regmap *regmap = isl12022->regmap;
+ int ret;
+ uint8_t buf[ISL12022_REG_DW + 1];
+
+ dev_dbg(dev, "%s: %ptR\n", __func__, tm);
+
+ /* Ensure the write enable bit is set. */
+ ret = regmap_update_bits(regmap, ISL12022_REG_INT,
+ ISL12022_INT_WRTC, ISL12022_INT_WRTC);
+ if (ret)
+ return ret;
+
+ /* hours, minutes and seconds */
+ buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
+ buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
+ buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
+
+ buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
+
+ /* month, 1 - 12 */
+ buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
+
+ /* year and century */
+ buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
+
+ buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
+
+ return regmap_bulk_write(isl12022->regmap, ISL12022_REG_SC,
+ buf, sizeof(buf));
+}
+
+static const struct rtc_class_ops isl12022_rtc_ops = {
+ .read_time = isl12022_rtc_read_time,
+ .set_time = isl12022_rtc_set_time,
+};
+
+static const struct regmap_config regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .use_single_write = true,
+};
+
+static int isl12022_probe(struct i2c_client *client)
+{
+ struct isl12022 *isl12022;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -ENODEV;
+
+ isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
+ GFP_KERNEL);
+ if (!isl12022)
+ return -ENOMEM;
+ dev_set_drvdata(&client->dev, isl12022);
+
+ isl12022->regmap = devm_regmap_init_i2c(client, &regmap_config);
+ if (IS_ERR(isl12022->regmap)) {
+ dev_err(&client->dev, "regmap allocation failed\n");
+ return PTR_ERR(isl12022->regmap);
+ }
+
+ isl12022->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(isl12022->rtc))
+ return PTR_ERR(isl12022->rtc);
+
+ isl12022->rtc->ops = &isl12022_rtc_ops;
+ isl12022->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ isl12022->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+ return devm_rtc_register_device(isl12022->rtc);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id isl12022_dt_match[] = {
+ { .compatible = "isl,isl12022" }, /* for backward compat., don't use */
+ { .compatible = "isil,isl12022" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, isl12022_dt_match);
+#endif
+
+static const struct i2c_device_id isl12022_id[] = {
+ { "isl12022", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, isl12022_id);
+
+static struct i2c_driver isl12022_driver = {
+ .driver = {
+ .name = "rtc-isl12022",
+#ifdef CONFIG_OF
+ .of_match_table = of_match_ptr(isl12022_dt_match),
+#endif
+ },
+ .probe_new = isl12022_probe,
+ .id_table = isl12022_id,
+};
+
+module_i2c_driver(isl12022_driver);
+
+MODULE_AUTHOR("roman.fietze@telemotive.de");
+MODULE_DESCRIPTION("ISL 12022 RTC driver");
+MODULE_LICENSE("GPL");