| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20140320192249.72f0288a@linux.lan.towertech.it>
Date: Thu, 20 Mar 2014 19:22:49 +0100
From: Alessandro Zummo <a.zummo@...ertech.it>
To: RAGHAVENDRA GANIGA <ravi23ganiga@...il.com>
Cc: linux-kernel@...r.kernel.org, rtc-linux@...glegroups.com
Subject: Re: [PATCH] rtc: add support for maxim dallas rtc ds1347
On Thu, 20 Mar 2014 21:55:33 +0530
RAGHAVENDRA GANIGA <ravi23ganiga@...il.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@...il.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@...il.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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists