Messages in this thread | | | Date | Thu, 20 Mar 2014 19:22:49 +0100 | From | Alessandro Zummo <> | Subject | Re: [PATCH] rtc: add support for maxim dallas rtc ds1347 |
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On Thu, 20 Mar 2014 21:55:33 +0530 RAGHAVENDRA GANIGA <ravi23ganiga@gmail.com> wrote:
Thanks for your submission! just a few comments below:
> --- > drivers/rtc/Kconfig | 12 ++++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-ds1347.c | 175 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 188 insertions(+) > create mode 100644 drivers/rtc/rtc-ds1347.c > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index db933de..2e565f8 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -573,6 +573,18 @@ 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_DS1347 > + tristate "Dallas/Maxim DS1347" > + help > + If you say yes here you get support for the > + Dallas/Maxim DS1347 chips. > + > + This driver only supports the RTC feature, and not other chip > + features such as alarms. > + > + This driver can also be built as a module. If so, the module > + will be called rtc-ds1347. > + > config RTC_DRV_DS1390 > tristate "Dallas/Maxim DS1390/93/94" > help > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index b427bf7..40a0991 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -40,6 +40,7 @@ obj-$(CONFIG_RTC_DRV_DS1286) += rtc-ds1286.o > obj-$(CONFIG_RTC_DRV_DS1302) += rtc-ds1302.o > obj-$(CONFIG_RTC_DRV_DS1305) += rtc-ds1305.o > obj-$(CONFIG_RTC_DRV_DS1307) += rtc-ds1307.o > +obj-$(CONFIG_RTC_DRV_DS1347) += rtc-ds1347.o > obj-$(CONFIG_RTC_DRV_DS1374) += rtc-ds1374.o > obj-$(CONFIG_RTC_DRV_DS1390) += rtc-ds1390.o > obj-$(CONFIG_RTC_DRV_DS1511) += rtc-ds1511.o > diff --git a/drivers/rtc/rtc-ds1347.c b/drivers/rtc/rtc-ds1347.c > new file mode 100644 > index 0000000..3c9a934 > --- /dev/null > +++ b/drivers/rtc/rtc-ds1347.c > @@ -0,0 +1,175 @@ > +/* rtc-ds1347.c > + * > + * Driver for Dallas Semiconductor DS1347 Low Current, SPI Compatible > + * Real Time Clock > + * > + * Author : Raghavendra Chandra Ganiga <ravi23ganiga@gmail.com> > + * > + * 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/init.h> > +#include <linux/module.h> > +#include <linux/device.h> > +#include <linux/platform_device.h> > +#include <linux/rtc.h> > +#include <linux/spi/spi.h> > +#include <linux/bcd.h> > + > +/*Registers in ds1347 rtc*/ > + > +#define DS1347_SECONDS_REG 0x01 > +#define DS1347_MINUTES_REG 0x03 > +#define DS1347_HOURS_REG 0x05 > +#define DS1347_DATE_REG 0x07 > +#define DS1347_MONTH_REG 0x09 > +#define DS1347_DAY_REG 0x0B > +#define DS1347_YEAR_REG 0x0D > +#define DS1347_CONTROL_REG 0x0F > +#define DS1347_STATUS_REG 0x17 > +#define DS1347_CLOCK_BURST 0x3F > + > + > + > +static int ds1347_read_reg(struct device *dev, unsigned char address, > + unsigned char *data) > +{ > + struct spi_device *spi = to_spi_device(dev); > + > + *data = address | 0x80; > + > + return spi_write_then_read(spi, data, 1, data, 1); > +} > + > +static int ds1347_write_reg(struct device *dev, unsigned char address, > + unsigned char data) > +{ > + struct spi_device *spi = to_spi_device(dev); > + unsigned char buf[2]; > + > + buf[0] = address & 0x7F; > + buf[1] = data; > + > + return spi_write_then_read(spi, buf, 2, NULL, 0); > +} > + > +static int ds1347_read_time(struct device *dev, struct rtc_time *dt) > +{ > + struct spi_device *spi = to_spi_device(dev); > + int err; > + unsigned char buf[8]; > + > + buf[0] = DS1347_CLOCK_BURST | 0x80; > + > + err = spi_write_then_read(spi, buf, 1, buf, 8); > + if (err) > + return err; > + > + dt->tm_sec = bcd2bin(buf[0]); > + dt->tm_min = bcd2bin(buf[1]); > + dt->tm_hour = bcd2bin(buf[2] & 0x3F); > + dt->tm_mday = bcd2bin(buf[3]); > + dt->tm_mon = bcd2bin(buf[4]) - 1; > + dt->tm_wday = bcd2bin(buf[5]) - 1; > + dt->tm_year = bcd2bin(buf[6]) + 100; > + > + return rtc_valid_tm(dt); > +} > + > +static int ds1347_set_time(struct device *dev, struct rtc_time *dt) > +{ > + struct spi_device *spi = to_spi_device(dev); > + unsigned char buf[9]; > + > + buf[0] = DS1347_CLOCK_BURST & 0x7F; > + buf[1] = bin2bcd(dt->tm_sec); > + buf[2] = bin2bcd(dt->tm_min); > + buf[3] = (bin2bcd(dt->tm_hour) & 0x3F); > + buf[4] = bin2bcd(dt->tm_mday); > + buf[5] = bin2bcd(dt->tm_mon + 1); > + buf[6] = bin2bcd(dt->tm_wday + 1); > + > + /*year in linux is from 1900 i.e in range of 100 > + in rtc it is from 00 to 99 so subtract
please leave a space after /*
> + the linux year by 100*/
and before */
(ditto for the other comments)
> + if (dt->tm_year >= 100) > + dt->tm_year -= 100; > + > + buf[7] = bin2bcd(dt->tm_year); > + buf[8] = bin2bcd(0x00); > + > + /*write the rtc settings*/ > + return spi_write_then_read(spi, buf, 9, NULL, 0); > +} > + > + > +
extra white lines
> +static const struct rtc_class_ops ds1347_rtc_ops = { > + .read_time = ds1347_read_time, > + .set_time = ds1347_set_time, > +}; > + > +static int ds1347_probe(struct spi_device *spi) > +{ > + struct rtc_device *rtc; > + unsigned char data; > + int res; > + > + /*spi setup with ds1347 in mode 3 and bits per word as 8*/ > + spi->mode = SPI_MODE_3; > + spi->bits_per_word = 8; > + spi_setup(spi); > + > + /*RTC Settings*/ > +
unnecessary comment
> + /*check if spi read is successfull*/
unnecessary comment, this is pretty clear
> + res = ds1347_read_reg(&spi->dev, DS1347_SECONDS_REG, &data); > + if (res) > + return res; > + > + /*Disable the write protect of rtc*/ > + ds1347_read_reg(&spi->dev, DS1347_CONTROL_REG, &data); > + data = data & ~(1<<7); > + ds1347_write_reg(&spi->dev, DS1347_CONTROL_REG, data); > + > + /*Enable the oscillator , disable the oscillator stop flag, > + and glitch filter to reduce current consumption*/ > + ds1347_read_reg(&spi->dev, DS1347_STATUS_REG, &data); > + data = data & 0x1B; > + ds1347_write_reg(&spi->dev, DS1347_STATUS_REG, data); > + > + /*display the settings*/ > + ds1347_read_reg(&spi->dev, DS1347_CONTROL_REG, &data); > + dev_info(&spi->dev, "DS1347 RTC CTRL Reg = 0x%02x\n", data); > + > + ds1347_read_reg(&spi->dev, DS1347_STATUS_REG, &data); > + dev_info(&spi->dev, "DS1347 RTC Status Reg = 0x%02x\n", data); > + > + rtc = devm_rtc_device_register(&spi->dev, "ds1347", > + &ds1347_rtc_ops, THIS_MODULE); > + > + if (IS_ERR(rtc)) > + return PTR_ERR(rtc); > + > + spi_set_drvdata(spi, rtc); > + > + return 0; > +} > + > +static struct spi_driver ds1347_driver = { > + .driver = { > + .name = "ds1347", > + .owner = THIS_MODULE, > + }, > + .probe = ds1347_probe, > +}; > + > +module_spi_driver(ds1347_driver); > + > +MODULE_DESCRIPTION("DS1347 SPI RTC DRIVER"); > +MODULE_AUTHOR("Raghavendra C Ganiga <ravi23ganiga@gmail.com>"); > +MODULE_LICENSE("GPL");
should be GPL v2 as you declared in the comments at the top of the file.
--
Best regards,
Alessandro Zummo, Tower Technologies - Torino, Italy
http://www.towertech.it
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