From: Venkat Prashanth B U <[email protected]> This is a patch to add support for maxim/dallas I2C rtc ds1683 chip.
Signed-off-by: Venkat Prashanth B U <[email protected]> --- drivers/rtc/Kconfig | 9 +++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-ds1683.c | 203 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 213 insertions(+) diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index e0e58f3..2528b79 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -294,6 +294,15 @@ config RTC_DRV_DS1672 This driver can also be built as a module. If so, the module will be called rtc-ds1672. +config RTC_DRV_DS1683 + tristate "Dallas/Maxim DS1683" + help + If you say yes here you get support for the + Dallas/Maxim DS1683 I2C timekeeping chip. + + This driver can also be built as a module. If so, the module + will be called rtc-ds1683. + config RTC_DRV_HYM8563 tristate "Haoyu Microelectronics HYM8563" depends on OF diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 0bf1fc0..a6f4419 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -62,6 +62,7 @@ obj-$(CONFIG_RTC_DRV_DS1390) += rtc-ds1390.o obj-$(CONFIG_RTC_DRV_DS1511) += rtc-ds1511.o obj-$(CONFIG_RTC_DRV_DS1553) += rtc-ds1553.o obj-$(CONFIG_RTC_DRV_DS1672) += rtc-ds1672.o +obj-$(CONFIG_RTC_DRV_DS1683) += rtc-ds1683.o obj-$(CONFIG_RTC_DRV_DS1685_FAMILY) += rtc-ds1685.o obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o obj-$(CONFIG_RTC_DRV_DS2404) += rtc-ds2404.o diff --git a/drivers/rtc/rtc-ds1683.c b/drivers/rtc/rtc-ds1683.c index e69de29..7b6dac3 100644 --- a/drivers/rtc/rtc-ds1683.c +++ b/drivers/rtc/rtc-ds1683.c @@ -0,0 +1,203 @@ +/* rtc-ds1683.c + * + * Driver for Maxim/Dallas ds1683, I2C Compatible + * Real Time Clock + * + * Author : Venkat Prashanth B U <[email protected]> + * + * 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. + * + */ + +#include <linux/i2c.h> +#include <linux/rtc.h> +#include <linux/module.h> + +/* Registers */ + +#define ds1683_REG_CNT_BASE 0 +#define ds1683_REG_EVENT 4 + +#define ds1683_REG_CONTROL_EOSC 0x80 + +static struct i2c_driver ds1683_driver; + +static int ds1683_get_datetime(struct i2c_client *client, struct rtc_time *tm) +{ + unsigned long time; + unsigned char addr = ds1683_REG_CNT_BASE; + unsigned char buf[4]; + + struct i2c_msg msgs[] = { + { /* setup read pointer */ + .addr = client->addr, + .len = 1, + .buf = &addr + }, + {/* read date */ + .addr = client->addr, + .flags = I2C_M_RD, + .len = 4, + .buf = buf + }, + }; + + /* read date registers */ + if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { + dev_err(&client->dev, "%s: read error\n", __func__); + return -EIO; + } + + time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; + + rtc_time_to_tm(time, tm); + + return 0; +} + +static int ds1683_set_mmss(struct i2c_client *client, unsigned long secs) +{ + int xfer; + unsigned char buf[6]; + + buf[0] = ds1683_REG_CNT_BASE; + buf[1] = secs & 0x000000FF; + buf[2] = (secs & 0x0000FF00) >> 8; + buf[3] = (secs & 0x00FF0000) >> 16; + buf[4] = (secs & 0xFF000000) >> 24; + buf[5] = 0; /* set control reg to enable counting */ + + xfer = i2c_master_send(client, buf, 6); + if (xfer != 6) { + dev_err(&client->dev, "%s: send: %d\n", __func__, xfer); + return -EIO; + } + + return 0; +} + +static int ds1683_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + return ds1683_get_datetime(to_i2c_client(dev), tm); +} + +static int ds1683_rtc_set_mmss(struct device *dev, unsigned long secs) +{ + return ds1683_set_mmss(to_i2c_client(dev), secs); +} + +static int ds1683_get_control(struct i2c_client *client, u8 *status) +{ + unsigned char addr = ds1683_REG_CONTROL; + + struct i2c_msg msgs[] = { + {/* setup read pointer */ + .addr = client->addr, + .len = 1, + .buf = &addr + }, + {/* read control */ + .addr = client->addr, + .flags = I2C_M_RD, + .len = 1, + .buf = status + }, + }; + + /* read control register */ + if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { + dev_err(&client->dev, "%s: read error\n", __func__); + return -EIO; + } + + return 0; +} + +/* sysfs callback functions */ +static ssize_t show_control(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + u8 control; + int err; + + err = ds1683_get_control(client, &control); + if (err) + return err; + + return sprintf(buf, "%s\n", (control & ds1683_REG_CONTROL_EOSC) + ? "disabled" : "enabled"); +} + +static DEVICE_ATTR(control, 0444, show_control, NULL); + +static const struct rtc_class_ops ds1683_rtc_ops = { + .read_time = ds1683_rtc_read_time, + .set_mmss = ds1683_rtc_set_mmss, +}; + +static int ds1683_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int err = 0; + u8 control; + struct rtc_device *rtc; + + dev_dbg(&client->dev, "%s\n", __func__); + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + rtc = devm_rtc_device_register(&client->dev, ds1683_driver.driver.name, + &ds1683_rtc_ops, THIS_MODULE); + + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + i2c_set_clientdata(client, rtc); + + /* read control register */ + err = ds1683_get_control(client, &control); + if (err) + dev_warn(&client->dev, "Unable to read the control register\n"); + + if (control & ds1683_REG_CONTROL_EOSC) + dev_warn(&client->dev, "Oscillator not enabled Set time to enable.\n"); + + /* Register sysfs hooks */ + err = device_create_file(&client->dev, &dev_attr_control); + if (err) + dev_err(&client->dev, "Unable to create sysfs entry: %s\n", + dev_attr_control.attr.name); + + return 0; +} + +static const struct i2c_device_id ds1683_id[] = { + { "ds1683", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ds1683_id); + +static const struct of_device_id ds1683_of_match[] = { + { "dallas,ds1683", 0 }, + { } +}; +MODULE_DEVICE_TABLE(of, ds1683_of_match); + +static struct i2c_driver ds1683_driver = { + .driver = { + .name = "rtc-ds1683", + .of_match_table = of_match_ptr(ds1683_of_match), + }, + .probe = &ds1683_probe, + .id_table = ds1683_id, +}; + +module_i2c_driver(ds1683_driver); + +MODULE_AUTHOR("Venkat Prashanth B U <[email protected]>"); +MODULE_DESCRIPTION("Dallas/Maxim ds1683 I2C driver"); +MODULE_LICENSE("GPL"); -- 1.9.1 -- You received this message because you are subscribed to "rtc-linux". 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