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Message-Id: <20240830-rtc-sd2405al-v7-1-2f7102621b1d@gmail.com>
Date: Fri, 30 Aug 2024 10:36:39 +0200
From: Tóth János via B4 Relay <devnull+gomba007.gmail.com@...nel.org>
To: Alexandre Belloni <alexandre.belloni@...tlin.com>,
Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>
Cc: linux-kernel@...r.kernel.org, linux-rtc@...r.kernel.org,
devicetree@...r.kernel.org,
Tóth János <gomba007@...il.com>,
Csókás Bence <csokas.bence@...lan.hu>
Subject: [PATCH v7 1/3] drivers: rtc: Add driver for SD2405AL.
From: Tóth János <gomba007@...il.com>
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
Reviewed-by: Csókás Bence <csokas.bence@...lan.hu>
Signed-off-by: Tóth János <gomba007@...il.com>
---
MAINTAINERS | 6 ++
drivers/rtc/Kconfig | 10 ++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-sd2405al.c | 227 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 244 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 878dcd23b331..cb4e5fcde44e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6476,6 +6476,12 @@ F: include/net/devlink.h
F: include/uapi/linux/devlink.h
F: net/devlink/
+DFROBOT SD2405AL RTC DRIVER
+M: Tóth János <gomba007@...il.com>
+L: linux-rtc@...r.kernel.org
+S: Maintained
+F: drivers/rtc/rtc-sd2405al.c
+
DH ELECTRONICS IMX6 DHCOM/DHCOR BOARD SUPPORT
M: Christoph Niedermaier <cniedermaier@...electronics.com>
L: kernel@...electronics.com
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..d2568c3e3876
--- /dev/null
+++ b/drivers/rtc/rtc-sd2405al.c
@@ -0,0 +1,227 @@
+// 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@...il.com>
+ */
+
+#include <linux/bcd.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+/* Real time clock registers */
+#define SD2405AL_REG_T_SEC 0x00
+#define SD2405AL_REG_T_MIN 0x01
+#define SD2405AL_REG_T_HOUR 0x02
+# define SD2405AL_BIT_12H_PM BIT(5)
+# define SD2405AL_BIT_24H BIT(7)
+#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_NUM_T_REGS (SD2405AL_REG_T_YEAR - SD2405AL_REG_T_SEC + 1)
+
+/* Control registers */
+#define SD2405AL_REG_CTR1 0x0F
+# define SD2405AL_BIT_WRTC2 BIT(2)
+# define SD2405AL_BIT_WRTC3 BIT(7)
+#define SD2405AL_REG_CTR2 0x10
+# define SD2405AL_BIT_WRTC1 BIT(7)
+#define SD2405AL_REG_CTR3 0x11
+#define SD2405AL_REG_TTF 0x12
+#define SD2405AL_REG_CNTDWN 0x13
+
+/* General RAM */
+#define SD2405AL_REG_M_START 0x14
+#define SD2405AL_REG_M_END 0x1F
+
+struct sd2405al {
+ struct device *dev;
+ struct rtc_device *rtc;
+ struct regmap *regmap;
+};
+
+static int sd2405al_enable_reg_write(struct sd2405al *sd2405al)
+{
+ int ret;
+
+ /* order of writes is important */
+ ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR2,
+ SD2405AL_BIT_WRTC1, SD2405AL_BIT_WRTC1);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR1,
+ SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3,
+ SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int sd2405al_disable_reg_write(struct sd2405al *sd2405al)
+{
+ int ret;
+
+ /* order of writes is important */
+ ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR1,
+ SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3, 0x00);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(sd2405al->regmap, SD2405AL_REG_CTR2,
+ SD2405AL_BIT_WRTC1, 0x00);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int sd2405al_read_time(struct device *dev, struct rtc_time *time)
+{
+ u8 data[SD2405AL_NUM_T_REGS] = { 0 };
+ struct sd2405al *sd2405al = dev_get_drvdata(dev);
+ int ret;
+
+ ret = regmap_bulk_read(sd2405al->regmap, SD2405AL_REG_T_SEC, data,
+ SD2405AL_NUM_T_REGS);
+ if (ret < 0)
+ return ret;
+
+ time->tm_sec = bcd2bin(data[SD2405AL_REG_T_SEC] & 0x7F);
+ time->tm_min = bcd2bin(data[SD2405AL_REG_T_MIN] & 0x7F);
+
+ if (data[SD2405AL_REG_T_HOUR] & SD2405AL_BIT_24H)
+ time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR] & 0x3F);
+ else
+ if (data[SD2405AL_REG_T_HOUR] & SD2405AL_BIT_12H_PM)
+ time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR]
+ & 0x1F) + 12;
+ else /* 12 hour mode, AM */
+ time->tm_hour = bcd2bin(data[SD2405AL_REG_T_HOUR]
+ & 0x1F);
+
+ time->tm_wday = bcd2bin(data[SD2405AL_REG_T_WEEK] & 0x07);
+ time->tm_mday = bcd2bin(data[SD2405AL_REG_T_DAY] & 0x3F);
+ time->tm_mon = bcd2bin(data[SD2405AL_REG_T_MON] & 0x1F) - 1;
+ time->tm_year = bcd2bin(data[SD2405AL_REG_T_YEAR]) + 100;
+
+ dev_dbg(sd2405al->dev, "read time: %ptR (%d)\n", time, time->tm_wday);
+
+ return 0;
+}
+
+static int sd2405al_set_time(struct device *dev, struct rtc_time *time)
+{
+ u8 data[SD2405AL_NUM_T_REGS];
+ struct sd2405al *sd2405al = dev_get_drvdata(dev);
+ 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] = bin2bcd(time->tm_wday);
+ data[SD2405AL_REG_T_MON] = bin2bcd(time->tm_mon) + 1;
+ data[SD2405AL_REG_T_YEAR] = bin2bcd(time->tm_year - 100);
+
+ ret = sd2405al_enable_reg_write(sd2405al);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_bulk_write(sd2405al->regmap, SD2405AL_REG_T_SEC, data,
+ SD2405AL_NUM_T_REGS);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_write(sd2405al->regmap, SD2405AL_REG_TTF, 0x00);
+ if (ret < 0)
+ return ret;
+
+ ret = sd2405al_disable_reg_write(sd2405al);
+ if (ret < 0)
+ return ret;
+
+ dev_dbg(sd2405al->dev, "set time: %ptR (%d)\n", time, time->tm_wday);
+
+ 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 ret;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -ENODEV;
+
+ sd2405al = devm_kzalloc(&client->dev, sizeof(*sd2405al), GFP_KERNEL);
+ if (!sd2405al)
+ return -ENOMEM;
+
+ sd2405al->dev = &client->dev;
+
+ sd2405al->regmap = devm_regmap_init_i2c(client, &sd2405al_regmap_conf);
+ if (IS_ERR(sd2405al->regmap))
+ return PTR_ERR(sd2405al->regmap);
+
+ sd2405al->rtc = devm_rtc_allocate_device(&client->dev);
+ if (IS_ERR(sd2405al->rtc))
+ 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;
+
+ dev_set_drvdata(&client->dev, sd2405al);
+
+ ret = devm_rtc_register_device(sd2405al->rtc);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static const struct i2c_device_id sd2405al_id[] = {
+ { "sd2405al" },
+ { /* 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 <gomba007@...il.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SD2405AL RTC driver");
--
2.34.1
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