From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Jackson Subject: [PATCH v3] Add Dallas DS1390 RTC chip Date: Mon, 20 Oct 2008 12:46:08 +0100 Message-ID: <48FC6F80.7030401@mimc.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: lkml , Alessandro Zummo , rtc-linux@googlegroups.com, spi-devel-general@lists.sourceforge.net To: dbrownell@users.sourceforge.net Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org v3 of this patch with some code tidying as per previous comments. Also only a single tx/rx buffer is used. This patch adds support for the Dallas DS1390 SPI RTC chip. Signed-off-by: Mark Jackson --- drivers/rtc/Kconfig | 14 +++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-ds1390.c | 256 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 271 insertions(+), 0 deletions(-) diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 9a9755c..7ec6abb 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -292,6 +292,20 @@ config RTC_DRV_DS1305 This driver can also be built as a module. If so, the module will be called rtc-ds1305. +config RTC_DRV_DS1390 + tristate "Dallas/Maxim DS1390" + help + If you say yes here you get support for the DS1390 and probably + other chips connected with SPI. + + The first seven registers on these chips hold an RTC, and other + registers may add features such as NVRAM, a trickle charger for + the RTC/NVRAM backup power, and alarms. This driver may not + expose all those available chip features. + + This driver can also be built as a module. If so, the module + will be called rtc-ds1390. + config RTC_DRV_MAX6902 tristate "Maxim MAX6902" help diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 18622ef..6306900 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_RTC_DRV_DS1302) += rtc-ds1302.o obj-$(CONFIG_RTC_DRV_DS1305) += rtc-ds1305.o obj-$(CONFIG_RTC_DRV_DS1307) += rtc-ds1307.o obj-$(CONFIG_RTC_DRV_DS1374) += rtc-ds1374.o +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 diff --git a/drivers/rtc/rtc-ds1390.c b/drivers/rtc/rtc-ds1390.c new file mode 100644 index 0000000..30f2fd8 --- /dev/null +++ b/drivers/rtc/rtc-ds1390.c @@ -0,0 +1,256 @@ +/* drivers/rtc/rtc-ds1390.c + * + * Copyright (C) 2008 Mercury IMC Ltd + * + * 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. + * + * Driver for DS1390 SPI RTC + * + * Changelog: + * + * 04-Apr-2008: Mark Jackson + * - Initial version based on rtc-max6902 + * - No alarm support though !! + */ + +#include +#include +#include +#include + +#define DS1390_REG_100THS 0x00 +#define DS1390_REG_SECONDS 0x01 +#define DS1390_REG_MINUTES 0x02 +#define DS1390_REG_HOURS 0x03 +#define DS1390_REG_DAY 0x04 +#define DS1390_REG_DATE 0x05 +#define DS1390_REG_MONTH_CENT 0x06 +#define DS1390_REG_YEAR 0x07 + +#define DS1390_REG_ALARM_100THS 0x08 +#define DS1390_REG_ALARM_SECONDS 0x09 +#define DS1390_REG_ALARM_MINUTES 0x0A +#define DS1390_REG_ALARM_HOURS 0x0B +#define DS1390_REG_ALARM_DAY_DATE 0x0C + +#define DS1390_REG_CONTROL 0x0D +#define DS1390_REG_STATUS 0x0E +#define DS1390_REG_TRICKLE 0x0F + +struct ds1390 { + struct rtc_device *rtc; + u8 txrx_buf[9]; /* cmd + 8 registers */ +}; + +static void ds1390_set_reg(struct device *dev, unsigned char address, + unsigned char data) +{ + struct spi_device *spi = to_spi_device(dev); + unsigned char buf[2]; + + /* MSB must be '1' to write */ + buf[0] = address | 0x80; + buf[1] = data; + + spi_write(spi, buf, 2); +} + +static int ds1390_get_reg(struct device *dev, unsigned char address, + unsigned char *data) +{ + struct spi_device *spi = to_spi_device(dev); + struct ds1390 *chip = dev_get_drvdata(dev); + struct spi_message message; + struct spi_transfer xfer; + int status; + + if (!data) + return -EINVAL; + + /* Build our spi message */ + spi_message_init(&message); + memset(&xfer, 0, sizeof(xfer)); + xfer.len = 2; + /* Can tx_buf and rx_buf be equal? Yes... */ + xfer.tx_buf = chip->txrx_buf; + xfer.rx_buf = chip->txrx_buf; + + /* Clear MSB to indicate read */ + chip->txrx_buf[0] = address & 0x7f; + + spi_message_add_tail(&xfer, &message); + + /* do the i/o */ + status = spi_sync(spi, &message); + if (status != 0) + return status; + + *data = chip->txrx_buf[1]; + + return message.status; +} + +static int ds1390_get_datetime(struct device *dev, struct rtc_time *dt) +{ + struct spi_device *spi = to_spi_device(dev); + struct ds1390 *chip = dev_get_drvdata(dev); + struct spi_message message; + struct spi_transfer xfer; + int status; + + /* build the message */ + spi_message_init(&message); + memset(&xfer, 0, sizeof(xfer)); + xfer.len = 1 + 7; /* read command + 7 registers */ + xfer.tx_buf = chip->txrx_buf; + xfer.rx_buf = chip->txrx_buf; + chip->txrx_buf[0] = DS1390_REG_SECONDS; + spi_message_add_tail(&xfer, &message); + + /* do the i/o */ + status = spi_sync(spi, &message); + if (status != 0) + return status; + + /* The chip sends data in this order: + * Seconds, Minutes, Hours, Day, Date, Month / Century, Year */ + dt->tm_sec = bcd2bin(chip->txrx_buf[1]); + dt->tm_min = bcd2bin(chip->txrx_buf[2]); + dt->tm_hour = bcd2bin(chip->txrx_buf[3]); + dt->tm_wday = bcd2bin(chip->txrx_buf[4]); + dt->tm_mday = bcd2bin(chip->txrx_buf[5]); + /* mask off century bit */ + dt->tm_mon = bcd2bin(chip->txrx_buf[6] & 0x7f) - 1; + /* adjust for century bit */ + dt->tm_year = bcd2bin(chip->txrx_buf[7]) + ((chip->txrx_buf[6] & 0x80) ? 100 : 0); + + return 0; +} + +static int ds1390_set_datetime(struct device *dev, struct rtc_time *dt) +{ + struct spi_device *spi = to_spi_device(dev); + struct ds1390 *chip = dev_get_drvdata(dev); + struct spi_message message; + struct spi_transfer xfer; + int status; + + /* build the message */ + spi_message_init(&message); + memset(&xfer, 0, sizeof(xfer)); + xfer.len = 1 + 8; /* write command + 8 registers */ + xfer.tx_buf = chip->txrx_buf; + xfer.rx_buf = chip->txrx_buf; + chip->txrx_buf[0] = DS1390_REG_SECONDS | 0x80; + chip->txrx_buf[1] = bin2bcd(dt->tm_sec); + chip->txrx_buf[2] = bin2bcd(dt->tm_min); + chip->txrx_buf[3] = bin2bcd(dt->tm_hour); + chip->txrx_buf[4] = bin2bcd(dt->tm_wday); + chip->txrx_buf[5] = bin2bcd(dt->tm_mday); + chip->txrx_buf[6] = bin2bcd(dt->tm_mon + 1) | + ((dt->tm_year > 99) ? 0x80 : 0x00); + chip->txrx_buf[7] = bin2bcd(dt->tm_year % 100); + spi_message_add_tail(&xfer, &message); + + /* do the i/o */ + status = spi_sync(spi, &message); + if (status == 0) + return message.status; + + return 0; +} + +static int ds1390_read_time(struct device *dev, struct rtc_time *tm) +{ + return ds1390_get_datetime(dev, tm); +} + +static int ds1390_set_time(struct device *dev, struct rtc_time *tm) +{ + return ds1390_set_datetime(dev, tm); +} + +static const struct rtc_class_ops ds1390_rtc_ops = { + .read_time = ds1390_read_time, + .set_time = ds1390_set_time, +}; + +static int __devinit ds1390_probe(struct spi_device *spi) +{ + struct rtc_device *rtc; + unsigned char tmp; + struct ds1390 *chip; + int res; + + printk(KERN_DEBUG "DS1390 SPI RTC driver\n"); + + rtc = rtc_device_register("ds1390", + &spi->dev, &ds1390_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) { + printk(KERN_ALERT "RTC : unable to register device\n"); + return PTR_ERR(rtc); + } + + spi->mode = SPI_MODE_3; + spi->bits_per_word = 8; + spi_setup(spi); + + chip = kzalloc(sizeof *chip, GFP_KERNEL); + if (!chip) { + printk(KERN_ALERT "RTC : unable to allocate device memory\n"); + rtc_device_unregister(rtc); + return -ENOMEM; + } + chip->rtc = rtc; + dev_set_drvdata(&spi->dev, chip); + + res = ds1390_get_reg(&spi->dev, DS1390_REG_SECONDS, &tmp); + if (res) { + printk(KERN_ALERT "RTC : unable to read device\n"); + rtc_device_unregister(rtc); + return res; + } + + return 0; +} + +static int __devexit ds1390_remove(struct spi_device *spi) +{ + struct ds1390 *chip = platform_get_drvdata(spi); + struct rtc_device *rtc = chip->rtc; + + if (rtc) + rtc_device_unregister(rtc); + + kfree(chip); + + return 0; +} + +static struct spi_driver ds1390_driver = { + .driver = { + .name = "rtc-ds1390", + .bus = &spi_bus_type, + .owner = THIS_MODULE, + }, + .probe = ds1390_probe, + .remove = __devexit_p(ds1390_remove), +}; + +static __init int ds1390_init(void) +{ + return spi_register_driver(&ds1390_driver); +} +module_init(ds1390_init); + +static __exit void ds1390_exit(void) +{ + spi_unregister_driver(&ds1390_driver); +} +module_exit(ds1390_exit); + +MODULE_DESCRIPTION("DS1390 SPI RTC driver"); +MODULE_AUTHOR("Mark Jackson "); +MODULE_LICENSE("GPL");