[PATCH] drivers: rtc: Add driver for SD2405AL.

From: Tóth János via B4 Relay
Date: Fri Jun 07 2024 - 08:20:59 EST

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From: Tóth János <gomba007@xxxxxxxxx>

Add support for the DFRobot SD2405AL I2C RTC Module.

Datasheet:
https://image.dfrobot.com/image/data/TOY0021/SD2405AL%20datasheet%20(Angelo%20v0.1).pdf

Product:
https://www.dfrobot.com/product-1600.html

To instantiate (assuming device is connected to I2C-1)
as root:
echo sd2405al 0x32 > /sys/bus/i2c/devices/i2c-1/new_device
as user:
echo 'sd2405al 0x32' | sudo tee /sys/class/i2c-adapter/i2c-1/new_device

The driver is tested with:
+ hwclock
+ tools/testing/selftests/rtc/setdate
+ tools/testing/selftests/rtc/rtctest

Signed-off-by: Tóth János <gomba007@xxxxxxxxx>
---
MAINTAINERS | 6 ++
drivers/rtc/Kconfig | 10 +++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-sd2405al.c | 195 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 212 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 8754ac2c259d..c78587811433 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6337,6 +6337,12 @@ F: include/net/devlink.h
F: include/uapi/linux/devlink.h
F: net/devlink/

+DFROBOT SD2405AL RTC DRIVER
+M: Tóth János <gomba007@xxxxxxxxx>
+L: linux-rtc@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/rtc/rtc-sd2405al.c
+
DH ELECTRONICS IMX6 DHCOM/DHCOR BOARD SUPPORT
M: Christoph Niedermaier <cniedermaier@xxxxxxxxxxxxxxxxxx>
L: kernel@xxxxxxxxxxxxxxxxxx
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2a95b05982ad..15f1c0ba5759 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -743,6 +743,16 @@ config RTC_DRV_S5M
This driver can also be built as a module. If so, the module
will be called rtc-s5m.

+config RTC_DRV_SD2405AL
+ tristate "DFRobot SD2405AL"
+ select REGMAP_I2C
+ help
+ If you say yes here you will get support for the
+ DFRobot SD2405AL I2C RTC Module.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-sd2405al.
+
config RTC_DRV_SD3078
tristate "ZXW Shenzhen whwave SD3078"
select REGMAP_I2C
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 3004e372f25f..3d19feba1e1c 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -162,6 +162,7 @@ obj-$(CONFIG_RTC_DRV_S3C) += rtc-s3c.o
obj-$(CONFIG_RTC_DRV_S5M) += rtc-s5m.o
obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o
obj-$(CONFIG_RTC_DRV_SC27XX) += rtc-sc27xx.o
+obj-$(CONFIG_RTC_DRV_SD2405AL) += rtc-sd2405al.o
obj-$(CONFIG_RTC_DRV_SD3078) += rtc-sd3078.o
obj-$(CONFIG_RTC_DRV_SH) += rtc-sh.o
obj-$(CONFIG_RTC_DRV_SNVS) += rtc-snvs.o
diff --git a/drivers/rtc/rtc-sd2405al.c b/drivers/rtc/rtc-sd2405al.c
new file mode 100644
index 000000000000..3250c4616aa3
--- /dev/null
+++ b/drivers/rtc/rtc-sd2405al.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RTC driver for the SD2405AL Real-Time Clock
+ *
+ * Datasheet:
+ * https://image.dfrobot.com/image/data/TOY0021/SD2405AL%20datasheet%20(Angelo%20v0.1).pdf
+ *
+ * Copyright (C) 2024 Tóth János <gomba007@xxxxxxxxx>
+ * Copyright (C) 2018 Zoro Li <long17.cool@xxxxxxx>
+ */
+
+#include <linux/bcd.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+#define SD2405AL_REG_T_SEC 0x00
+#define SD2405AL_REG_T_MIN 0x01
+#define SD2405AL_REG_T_HOUR 0x02
+#define SD2405AL_REG_T_WEEK 0x03
+#define SD2405AL_REG_T_DAY 0x04
+#define SD2405AL_REG_T_MON 0x05
+#define SD2405AL_REG_T_YEAR 0x06
+
+#define SD2405AL_REG_A_SEC 0x07
+#define SD2405AL_REG_A_MIN 0x08
+#define SD2405AL_REG_A_HOUR 0x09
+#define SD2405AL_REG_A_WEEK 0x0A
+#define SD2405AL_REG_A_DAY 0x0B
+#define SD2405AL_REG_A_MON 0x0C
+#define SD2405AL_REG_A_YEAR 0x0D
+#define SD2405AL_REG_A_EN 0x0E
+
+#define SD2405AL_REG_CTR1 0x0F
+#define SD2405AL_REG_CTR2 0x10
+#define SD2405AL_REG_CTR3 0x11
+#define SD2405AL_REG_TTF 0x12
+#define SD2405AL_REG_CTR 0x13 /* count down register */
+
+#define SD2405AL_REG_M_START 0x14 /* general RAM start */
+#define SD2405AL_REG_M_END 0x1F /* general RAM end */
+
+#define SD2405AL_NUM_T_REGS (SD2405AL_REG_T_YEAR - SD2405AL_REG_T_SEC + 1)
+
+#define SD2405AL_BIT_24H 0x80
+#define SD2405AL_BIT_12H_PM 0x20
+
+struct sd2405al {
+ struct rtc_device *rtc;
+ struct regmap *regmap;
+};
+
+static int sd2405al_read_time(struct device *dev, struct rtc_time *time)
+{
+ u8 hour;
+ u8 data[SD2405AL_NUM_T_REGS] = { 0 };
+ struct i2c_client *client = to_i2c_client(dev);
+ struct sd2405al *sd2405al = i2c_get_clientdata(client);
+ int ret;
+
+ ret = regmap_bulk_read(sd2405al->regmap, SD2405AL_REG_T_SEC, data,
+ SD2405AL_NUM_T_REGS);
+ if (ret < 0) {
+ printk(KBUILD_MODNAME ": reading failed: %d\n", ret);
+ return ret;
+ }
+
+ time->tm_sec = bcd2bin(data[SD2405AL_REG_T_SEC] & 0x7F);
+ time->tm_min = bcd2bin(data[SD2405AL_REG_T_MIN] & 0x7F);
+
+ hour = data[SD2405AL_REG_T_HOUR];
+ if (hour & SD2405AL_BIT_24H)
+ time->tm_hour = bcd2bin(hour & 0x3F);
+ else
+ if (hour & SD2405AL_BIT_12H_PM)
+ time->tm_hour = bcd2bin(hour & 0x1F) + 12;
+ else /* 12 hour mode, AM */
+ time->tm_hour = bcd2bin(hour & 0x1F);
+
+ time->tm_mday = bcd2bin(data[SD2405AL_REG_T_DAY] & 0x3F);
+ time->tm_wday = data[SD2405AL_REG_T_WEEK] & 0x07;
+ time->tm_mon = bcd2bin(data[SD2405AL_REG_T_MON] & 0x1F) - 1;
+ time->tm_year = bcd2bin(data[SD2405AL_REG_T_YEAR]) + 100;
+
+ return 0;
+}
+
+static int sd2405al_set_time(struct device *dev, struct rtc_time *time)
+{
+ u8 data[SD2405AL_NUM_T_REGS];
+ struct i2c_client *client = to_i2c_client(dev);
+ struct sd2405al *sd2405al = i2c_get_clientdata(client);
+ int ret;
+
+ data[SD2405AL_REG_T_SEC] = bin2bcd(time->tm_sec);
+ data[SD2405AL_REG_T_MIN] = bin2bcd(time->tm_min);
+ data[SD2405AL_REG_T_HOUR] = bin2bcd(time->tm_hour) | SD2405AL_BIT_24H;
+ data[SD2405AL_REG_T_DAY] = bin2bcd(time->tm_mday);
+ data[SD2405AL_REG_T_WEEK] = time->tm_wday & 0x07;
+ data[SD2405AL_REG_T_MON] = bin2bcd(time->tm_mon) + 1;
+ data[SD2405AL_REG_T_YEAR] = bin2bcd(time->tm_year - 100);
+
+ ret = regmap_bulk_write(sd2405al->regmap, SD2405AL_REG_T_SEC, data,
+ SD2405AL_NUM_T_REGS);
+ if (ret < 0) {
+ printk(KBUILD_MODNAME ": writing failed: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct rtc_class_ops sd2405al_rtc_ops = {
+ .read_time = sd2405al_read_time,
+ .set_time = sd2405al_set_time,
+};
+
+static const struct regmap_config sd2405al_regmap_conf = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = SD2405AL_REG_M_END,
+};
+
+static int sd2405al_probe(struct i2c_client *client)
+{
+ struct sd2405al *sd2405al;
+ int func;
+ int ret;
+
+ func = i2c_check_functionality(client->adapter, I2C_FUNC_I2C);
+ if (!func) {
+ printk(KBUILD_MODNAME ": invalid adapter\n");
+ return -ENODEV;
+ }
+
+ sd2405al = devm_kzalloc(&client->dev, sizeof(*sd2405al), GFP_KERNEL);
+ if (!sd2405al) {
+ printk(KBUILD_MODNAME ": unable to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ sd2405al->regmap = devm_regmap_init_i2c(client, &sd2405al_regmap_conf);
+ if (IS_ERR(sd2405al->regmap)) {
+ printk(KBUILD_MODNAME ": unable to allocate regmap\n");
+ return PTR_ERR(sd2405al->regmap);
+ }
+
+ i2c_set_clientdata(client, sd2405al);
+
+ sd2405al->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(sd2405al->rtc)) {
+ printk(KBUILD_MODNAME ": unable to allocate device\n");
+ return PTR_ERR(sd2405al->rtc);
+ }
+
+ sd2405al->rtc->ops = &sd2405al_rtc_ops;
+ sd2405al->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ sd2405al->rtc->range_max = RTC_TIMESTAMP_END_2099;
+
+ ret = devm_rtc_register_device(sd2405al->rtc);
+ if (ret < 0) {
+ printk(KBUILD_MODNAME ": unable to register device: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct i2c_device_id sd2405al_id[] = {
+ { "sd2405al", 0 },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, sd2405al_id);
+
+static const __maybe_unused struct of_device_id sd2405al_of_match[] = {
+ { .compatible = "dfrobot,sd2405al" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sd2405al_of_match);
+
+static struct i2c_driver sd2405al_driver = {
+ .driver = {
+ .name = "sd2405al",
+ .of_match_table = of_match_ptr(sd2405al_of_match),
+ },
+ .probe = sd2405al_probe,
+ .id_table = sd2405al_id,
+};
+
+module_i2c_driver(sd2405al_driver);
+
+MODULE_AUTHOR("Tóth János");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SD2405AL RTC driver");

---
base-commit: c3f38fa61af77b49866b006939479069cd451173
change-id: 20240607-rtc-sd2405al-a0947377c73d

Best regards,
--
Tóth János <gomba007@xxxxxxxxx>

Next message: Konstantin Komarov: "[PATCH 00/18] Bugfix and refactoring"
Previous message: Dimitri Fedrau: "[PATCH v4 2/2] pwm: add support for NXPs high-side switch MC33XS2410"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]