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> --- Changes in v4: - Implement more comprehensive data validation. - Inline some temporary variables. - Link to v3: https://lore.kernel.org/r/20240620-rtc-sd2405al-v3-1-65d5bb01af50@xxxxxxxxx Changes in v3: - #define-s of registers are reworked. - Minor revisions based on the reviewer's suggestions. - Link to v2: https://lore.kernel.org/r/20240619-rtc-sd2405al-v2-1-39bea29bd2a5@xxxxxxxxx Changes in v2: - Refactored based on reviewer's suggestions. - I couldn't get the I2C IRQ to work on Raspberry Pi 4, so alarm is skipped. - Link to v1: https://lore.kernel.org/r/20240607-rtc-sd2405al-v1-1-535971e7a866@xxxxxxxxx --- MAINTAINERS | 6 + drivers/rtc/Kconfig | 10 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-sd2405al.c | 319 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 336 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..5440cc1aed1d --- /dev/null +++ b/drivers/rtc/rtc-sd2405al.c @@ -0,0 +1,319 @@ +// 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> (rtc-sd3078.c) + * Copyright (C) 2005 James Chapman (rtc-ds1307.c) + */ + +#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(6) +#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_check_writable(struct sd2405al *sd2405al) +{ + u8 data[2] = { 0 }; + int ret; + + ret = regmap_bulk_read(sd2405al->regmap, SD2405AL_REG_CTR1, data, 2); + if (ret < 0) { + dev_err(sd2405al->dev, "read failed: %d\n", ret); + return ret; + } + + return (data[0] & (SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3)) != 0 && + (data[1] & SD2405AL_BIT_WRTC1) != 0; +} + +static int sd2405al_setup(struct sd2405al *sd2405al) +{ + int ret; + + /* order of writes is important */ + /* + * CTR2.WRTC1 = 1, device is writable + * CTR2.IM = 0, single event alarm + * CTR2.S{1,0} = 0, disable INT pin + * CTR2.FOBAT = 0, interrupt enabled during battery backup mode + * CTR2.INTDE = 0, countdown interrupt disabled + * CTR2.INTAE = 0, alarm interrupt disabled + * CTR2.INTFE = 0, frequency interrupt disabled + */ + ret = regmap_write(sd2405al->regmap, SD2405AL_REG_CTR2, + SD2405AL_BIT_WRTC1); + if (ret < 0) { + dev_err(sd2405al->dev, "write failed: %d\n", ret); + return ret; + } + + /* + * CTR2.WRTC3 = 1, device is writable + * CTR1.INTAF = 0, clear alarm interrupt flag + * CTR2.INTDF = 0, clear countdown interrupt flag + * CTR2.WRTC2 = 1, device is writable + */ + ret = regmap_write(sd2405al->regmap, SD2405AL_REG_CTR1, + SD2405AL_BIT_WRTC2 | SD2405AL_BIT_WRTC3); + if (ret < 0) { + dev_err(sd2405al->dev, "write failed: %d\n", ret); + return ret; + } + + /* + * CRT3.ARTS = 0, disable auto reset of interrupt flags + * CTR3.TDS{1,0} = 0, unused, since countdown interrupt is disabled + * CTR3.FS{3,2,1,0} = 0, unused since frequency interrupt is disabled + */ + ret = regmap_write(sd2405al->regmap, SD2405AL_REG_CTR3, 0); + if (ret < 0) { + dev_err(sd2405al->dev, "write failed: %d\n", ret); + return ret; + } + + ret = sd2405al_check_writable(sd2405al); + if (ret == 0) { + dev_err(sd2405al->dev, "device is not writable\n"); + return -EINVAL; + } else if (ret < 0) { + return ret; + } else { + dev_dbg(sd2405al->dev, "device is writable\n"); + } + + 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) { + dev_err(sd2405al->dev, "read failed: %d\n", ret); + return ret; + } + + if (data[SD2405AL_REG_T_SEC] & 0x80) { + dev_err(sd2405al->dev, "invalid second\n"); + return -EINVAL; + } + + if (data[SD2405AL_REG_T_MIN] & 0x80) { + dev_err(sd2405al->dev, "invalid minute\n"); + return -EINVAL; + } + + if (data[SD2405AL_REG_T_HOUR] & 0x40) { + dev_err(sd2405al->dev, "invalid hour\n"); + return -EINVAL; + } + + if (data[SD2405AL_REG_T_WEEK] & 0xF8) { + dev_err(sd2405al->dev, "invalid week\n"); + return -EINVAL; + } + + if (data[SD2405AL_REG_T_DAY] & 0xC0) { + dev_err(sd2405al->dev, "invalid day\n"); + return -EINVAL; + } + + if (data[SD2405AL_REG_T_MON] & 0xE0) { + dev_err(sd2405al->dev, "invalid month\n"); + return -EINVAL; + } + + 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 = 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: %d-%02d-%02d %02d:%02d:%02d\n", + time->tm_year, time->tm_mon, time->tm_mday, + time->tm_hour, time->tm_min, time->tm_sec); + + 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; + + ret = sd2405al_check_writable(sd2405al); + if (ret == 0) { + dev_err(sd2405al->dev, "device is not writable\n"); + return -EINVAL; + } else if (ret < 0) { + return ret; + } else { + dev_dbg(sd2405al->dev, "device is writable\n"); + } + + 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) { + dev_err(sd2405al->dev, "write failed: %d\n", ret); + return ret; + } + + dev_dbg(sd2405al->dev, "set time: %d-%02d-%02d %02d:%02d:%02d\n", + time->tm_year, time->tm_mon, time->tm_mday, + time->tm_hour, time->tm_min, time->tm_sec); + + 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) { + dev_err(&client->dev, "invalid adapter\n"); + return -ENODEV; + } + + sd2405al = devm_kzalloc(&client->dev, sizeof(*sd2405al), GFP_KERNEL); + if (!sd2405al) { + dev_err(&client->dev, "unable to allocate memory\n"); + return -ENOMEM; + } + + sd2405al->dev = &client->dev; + + sd2405al->regmap = devm_regmap_init_i2c(client, &sd2405al_regmap_conf); + if (IS_ERR(sd2405al->regmap)) { + dev_err(sd2405al->dev, "unable to allocate regmap\n"); + return PTR_ERR(sd2405al->regmap); + } + + ret = sd2405al_setup(sd2405al); + if (ret < 0) { + dev_err(sd2405al->dev, "unable to setup device\n"); + return ret; + } + + sd2405al->rtc = devm_rtc_allocate_device(&client->dev); + if (IS_ERR(sd2405al->rtc)) { + dev_err(sd2405al->dev, "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; + + dev_set_drvdata(&client->dev, sd2405al); + + ret = devm_rtc_register_device(sd2405al->rtc); + if (ret < 0) { + dev_err(sd2405al->dev, "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>
