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* [PATCH] rtc: add support for Maxim rtc max6916 v3.0
@ 2016-05-13  6:14 venkat.prashanth2498
  2016-05-13 16:05 ` [rtc-linux] " Krzysztof Kozlowski
  0 siblings, 1 reply; 2+ messages in thread
From: venkat.prashanth2498 @ 2016-05-13  6:14 UTC (permalink / raw)
  To: a.zummo
  Cc: rtc-linux, linux-kernel, alexandre.belloni, marcus.folkesson,
	venkat-prashanth

From: venkat-prashanth <venkat.prashanth2498@gmail.com>

This is a patch to add support 
for Maxim rtc max6916

Signed-off-by: Venkat Prashanth B U <venkat.prashanth2498@gmail.com>
---

                       #Change Log: from v2.0 to v3.0

                     - fixed the out-of-tree Makefile and suitably added
                       the modifications in the Makefile

                     - fixed the bad indented Kconfig file

                     -used a define instead of 0x1B as follows
		                #define MAX6916_REG_MAP_ADDRESS 0x1B

                     -moved and placed the test at the begining of the function
                      after the range is properly enforced
		               if (dt->tm_year < 100 || dt->tm_year > 199) {
                      dev_err(&spi->dev,"Year must be between 2000 and 2099.
                      It's %d.\n", dt->tm_year + 1900);
                      return -EINVAL;
                      }

                     - A magic number is a direct usage of a number
                       in the code,instead has been refactored in  the
                       current version v3.0 which use defines as follows:-
                     -max6916_read_reg(&spi->dev,
                      int MAX6916_CONTROL_REG = 0x08, &data);
                     -max6916_write_reg(&spi->dev,
                      int MAX6916_CONTROL_REG= 0x08, data);
                     -max6916_write_reg(&spi->dev,
                      int MAX6916_STATUS_REG = 0x0C, data);
                     -max6916_read_reg(&spi->dev,
                      int MAX6916_CONTROL_REG = 0x08, &data);
		               -max6916_read_reg(&spi->dev,
                      int MAX6916_STATUS_REG  = 0X0C,  &data);
                     -Unnecessary test function if(dt->tm_year >= 100)
                                                  dt->tm_year -= 100;
                      is deleted after the range is properly enforced.
                     -seperated logical code sections with an empty line
                      and used indentation after if-statements.
---
---
 Kconfig       |   9 ++++
 Makefile      |   1 +
 rtc-max6916.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 172 insertions(+)

diff --git a/driver/rtc/Kconfig b/driver/rtc/Kconfig
index fcf87da..5321e8f 100644
--- a/driver/rtc/Kconfig
+++ b/driver/rtc/Kconfig
@@ -699,6 +699,15 @@
  
               This driver can also be built as a module. If so, the module
               will be called rtc-max6902.
+    config RTC_DRV_MAX6916
+            tristate "Maxim MAX6916"
+            help
+              If you say yes here you will get support for the
+              Maxim MAX6916 SPI RTC chip.
+
+              This driver can also be built as a module. If so, the module
+              will be called rtc-max6916.
+
  
     config RTC_DRV_R9701
             tristate "Epson RTC-9701JE"
diff --git a/driver/rtc/Makefile b/driver/rtc/Makefile
index 9421959..0b3fded 100644
--- a/driver/rtc/Makefile
+++ b/driver/rtc/Makefile
@@ -85,6 +85,7 @@
     obj-$(CONFIG_RTC_DRV_M48T86)    += rtc-m48t86.o
     obj-$(CONFIG_RTC_DRV_MAX6900)   += rtc-max6900.o
     obj-$(CONFIG_RTC_DRV_MAX6902)   += rtc-max6902.o
    +obj-$(CONFIG_RTC_DRV_MAX6916)   += rtc-max6916.o
     obj-$(CONFIG_RTC_DRV_MAX77686)  += rtc-max77686.o
     obj-$(CONFIG_RTC_DRV_MAX77802)  += rtc-max77802.o
     obj-$(CONFIG_RTC_DRV_MAX8907)   += rtc-max8907.o
diff --git a/driver/rtc/rtc-max6916.c b/driver/rtc/rtc-max6916.c
index e69de29..ced341a 100644
--- a/driver/rtc/rtc-max6916.c
+++ b/driver/rtc/rtc-max6916.c
@@ -0,0 +1,162 @@
+#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 max6916 rtc */
+
+#define MAX6916_SECONDS_REG          0x01
+#define MAX6916_MINUTES_REG          0x02
+#define MAX6916_HOURS_REG            0x03
+#define MAX6916_DATE_REG             0x04
+#define MAX6916_MONTH_REG            0x05
+#define MAX6916_DAY_REG              0x06
+#define MAX6916_YEAR_REG             0x07
+#define MAX6916_CONTROL_REG          0x08
+#define MAX6916_STATUS_REG           0x0C
+#define MAX6916_CLOCK_BURST          0x3F
+#define MAX6916_REG_MAP_ADDRESS      0x1B
+
+static int max6916_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 max6916_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 max6916_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] = MAX6916_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 max6916_set_time(struct device *dev, struct rtc_time *dt)
+{
+			struct spi_device *spi = to_spi_device(dev);
+			unsigned char buf[9];
+
+			if (dt->tm_year < 100 || dt->tm_year > 199) {
+				dev_err(&spi->dev, "Year must be between 2000 and 2099.It's %d.\n", dt->tm_year+1900);
+			return -EINVAL;
+}
+
+			buf[0] = MAX6916_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);
+			buf[7] = bin2bcd(dt->tm_year % 100);
+			buf[8] = bin2bcd(0x00);
+
+			/* write the rtc settings */
+			return spi_write_then_read(spi, buf, 9, NULL, 0);
+}
+
+static const struct rtc_class_ops max6916_rtc_ops = {
+			.read_time = max6916_read_time,
+			.set_time = max6916_set_time,
+};
+
+static int max6916_probe(struct spi_device *spi)
+{
+			struct rtc_device *rtc;
+			unsigned char data;
+			int res;
+
+			/* spi setup with max6916 in mode 3 and bits per word as 8 */
+			spi->mode = SPI_MODE_3;
+			spi->bits_per_word = 8;
+			spi_setup(spi);
+
+			/* RTC Settings */
+			res = max6916_read_reg(&spi->dev, MAX6916_SECONDS_REG, &data);
+
+			if (res)
+				return res;
+
+			/* Disable the write protect of rtc */
+			max6916_read_reg(&spi->dev, int  MAX6916_CONTROL_REG = 0x08, &data);
+			data = data & ~(1<<7);
+			max6916_write_reg(&spi->dev, int MAX6916_CONTROL_REG = 0x08, data);
+
+			/*Enable the oscillator,disable the oscillator stop flag, and glitch filter to reduce current consumption*/
+			max6916_read_reg(&spi->dev, int MAX6916_STATUS_REG = 0X0C, &data);
+			data = data & MAX6916_REG_MAP_ADDRESS;
+			max6916_write_reg(&spi->dev, int MAX6916_STATUS_REG = 0x0C, data);
+
+			/* display the settings */
+			max6916_read_reg(&spi->dev, int MAX6916_CONTROL_REG = 0x08, &data);
+			dev_info(&spi->dev, "MAX6916 RTC CTRL Reg = 0x%02x\n", data);
+
+			max6916_read_reg(&spi->dev, int MAX6916_STATUS_REG = 0X0C, &data);
+			dev_info(&spi->dev, "MAX6916 RTC Status Reg = 0x%02x\n", data);
+
+			rtc = devm_rtc_device_register(&spi->dev, "max6916", &max6916_rtc_ops, THIS_MODULE);
+
+
+			if (IS_ERR(rtc))
+			return PTR_ERR(rtc);
+
+			spi_set_drvdata(spi, rtc);
+
+			return 0;
+}
+
+static struct spi_driver max6916_driver = {
+			.driver = {
+			.name = "max6916",
+			},
+			.probe = max6916_probe,
+};
+
+module_spi_driver(max6916_driver);
+
+MODULE_DESCRIPTION("MAX6916 SPI RTC DRIVER");
+MODULE_AUTHOR("Venkat Prashanth B U <venkat.prashanth2498@gmail.com>");
+MODULE_LICENSE("GPL v2");
+
+
+
+
+
+
+
+
+
-- 
1.9.2

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [rtc-linux] [PATCH] rtc: add support for Maxim rtc max6916 v3.0
  2016-05-13  6:14 [PATCH] rtc: add support for Maxim rtc max6916 v3.0 venkat.prashanth2498
@ 2016-05-13 16:05 ` Krzysztof Kozlowski
  0 siblings, 0 replies; 2+ messages in thread
From: Krzysztof Kozlowski @ 2016-05-13 16:05 UTC (permalink / raw)
  To: rtc-linux
  Cc: a.zummo, linux-kernel, alexandre.belloni, marcus.folkesson,
	venkat-prashanth

On Fri, May 13, 2016 at 8:14 AM,  <venkat.prashanth2498@gmail.com> wrote:
> From: venkat-prashanth <venkat.prashanth2498@gmail.com>
>
> This is a patch to add support
> for Maxim rtc max6916

Please fix line wrapping (around 72 characters).

Also please follow patch submission rules. Look at other patches with
versions - how "v4" is added (not to title) and prefix for driver,
after 'rtc'.

> Signed-off-by: Venkat Prashanth B U <venkat.prashanth2498@gmail.com>

>From name does not match Signed-off-by.

> ---
>
>                        #Change Log: from v2.0 to v3.0
>
>                      - fixed the out-of-tree Makefile and suitably added
>                        the modifications in the Makefile
>
>                      - fixed the bad indented Kconfig file
>
>                      -used a define instead of 0x1B as follows
 >                                 #define MAX6916_REG_MAP_ADDRESS 0x1B
>
>                      -moved and placed the test at the begining of the function
>                       after the range is properly enforced
>                                if (dt->tm_year < 100 || dt->tm_year > 199) {
>                       dev_err(&spi->dev,"Year must be between 2000 and 2099.
>                       It's %d.\n", dt->tm_year + 1900);
>                       return -EINVAL;
>                       }
>
>                      - A magic number is a direct usage of a number
>                        in the code,instead has been refactored in  the
>                        current version v3.0 which use defines as follows:-
>                      -max6916_read_reg(&spi->dev,
>                       int MAX6916_CONTROL_REG = 0x08, &data);
>                      -max6916_write_reg(&spi->dev,
>                       int MAX6916_CONTROL_REG= 0x08, data);
>                      -max6916_write_reg(&spi->dev,
>                       int MAX6916_STATUS_REG = 0x0C, data);
>                      -max6916_read_reg(&spi->dev,
>                       int MAX6916_CONTROL_REG = 0x08, &data);
>                                -max6916_read_reg(&spi->dev,
>                       int MAX6916_STATUS_REG  = 0X0C,  &data);
>                      -Unnecessary test function if(dt->tm_year >= 100)
>                                                   dt->tm_year -= 100;
>                       is deleted after the range is properly enforced.
>                      -seperated logical code sections with an empty line
>                       and used indentation after if-statements.

Indentation and line wrapping created unreadable piece of changelog.

> ---
> ---
>  Kconfig       |   9 ++++
>  Makefile      |   1 +
>  rtc-max6916.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

This looks wrong.

>  3 files changed, 172 insertions(+)
>
> diff --git a/driver/rtc/Kconfig b/driver/rtc/Kconfig
> index fcf87da..5321e8f 100644
> --- a/driver/rtc/Kconfig
> +++ b/driver/rtc/Kconfig
> @@ -699,6 +699,15 @@
>
>                This driver can also be built as a module. If so, the module
>                will be called rtc-max6902.
> +    config RTC_DRV_MAX6916
> +            tristate "Maxim MAX6916"
> +            help
> +              If you say yes here you will get support for the
> +              Maxim MAX6916 SPI RTC chip.
> +
> +              This driver can also be built as a module. If so, the module
> +              will be called rtc-max6916.
> +
>
>      config RTC_DRV_R9701
>              tristate "Epson RTC-9701JE"
> diff --git a/driver/rtc/Makefile b/driver/rtc/Makefile
> index 9421959..0b3fded 100644
> --- a/driver/rtc/Makefile
> +++ b/driver/rtc/Makefile
> @@ -85,6 +85,7 @@
>      obj-$(CONFIG_RTC_DRV_M48T86)    += rtc-m48t86.o
>      obj-$(CONFIG_RTC_DRV_MAX6900)   += rtc-max6900.o
>      obj-$(CONFIG_RTC_DRV_MAX6902)   += rtc-max6902.o
>     +obj-$(CONFIG_RTC_DRV_MAX6916)   += rtc-max6916.o
>      obj-$(CONFIG_RTC_DRV_MAX77686)  += rtc-max77686.o
>      obj-$(CONFIG_RTC_DRV_MAX77802)  += rtc-max77802.o
>      obj-$(CONFIG_RTC_DRV_MAX8907)   += rtc-max8907.o
> diff --git a/driver/rtc/rtc-max6916.c b/driver/rtc/rtc-max6916.c
> index e69de29..ced341a 100644
> --- a/driver/rtc/rtc-max6916.c
> +++ b/driver/rtc/rtc-max6916.c
> @@ -0,0 +1,162 @@
> +#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 max6916 rtc */
> +
> +#define MAX6916_SECONDS_REG          0x01
> +#define MAX6916_MINUTES_REG          0x02
> +#define MAX6916_HOURS_REG            0x03
> +#define MAX6916_DATE_REG             0x04
> +#define MAX6916_MONTH_REG            0x05
> +#define MAX6916_DAY_REG              0x06
> +#define MAX6916_YEAR_REG             0x07
> +#define MAX6916_CONTROL_REG          0x08
> +#define MAX6916_STATUS_REG           0x0C
> +#define MAX6916_CLOCK_BURST          0x3F
> +#define MAX6916_REG_MAP_ADDRESS      0x1B

Align the value with tabs. Make it readable.

> +
> +static int max6916_read_reg(struct device *dev, unsigned char address, unsigned char *data)
> +
> +{
> +                       struct spi_device *spi = to_spi_device(dev);

All of these indentations look wrong.

Have you run checkpatch? I doubt it. Run also sparse and smatch. Fix
all the warnings.

> +
> +                       *data = address | 0x80;
> +
> +                       return spi_write_then_read(spi, data, 1, data, 1);
> +}
> +
> +static int max6916_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 max6916_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] = MAX6916_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 max6916_set_time(struct device *dev, struct rtc_time *dt)
> +{
> +                       struct spi_device *spi = to_spi_device(dev);
> +                       unsigned char buf[9];
> +
> +                       if (dt->tm_year < 100 || dt->tm_year > 199) {
> +                               dev_err(&spi->dev, "Year must be between 2000 and 2099.It's %d.\n", dt->tm_year+1900);
> +                       return -EINVAL;
> +}
> +
> +                       buf[0] = MAX6916_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);
> +                       buf[7] = bin2bcd(dt->tm_year % 100);
> +                       buf[8] = bin2bcd(0x00);
> +
> +                       /* write the rtc settings */
> +                       return spi_write_then_read(spi, buf, 9, NULL, 0);
> +}
> +
> +static const struct rtc_class_ops max6916_rtc_ops = {
> +                       .read_time = max6916_read_time,
> +                       .set_time = max6916_set_time,
> +};
> +
> +static int max6916_probe(struct spi_device *spi)
> +{
> +                       struct rtc_device *rtc;
> +                       unsigned char data;
> +                       int res;
> +
> +                       /* spi setup with max6916 in mode 3 and bits per word as 8 */
> +                       spi->mode = SPI_MODE_3;
> +                       spi->bits_per_word = 8;
> +                       spi_setup(spi);
> +
> +                       /* RTC Settings */
> +                       res = max6916_read_reg(&spi->dev, MAX6916_SECONDS_REG, &data);
> +
> +                       if (res)
> +                               return res;
> +
> +                       /* Disable the write protect of rtc */
> +                       max6916_read_reg(&spi->dev, int  MAX6916_CONTROL_REG = 0x08, &data);
> +                       data = data & ~(1<<7);
> +                       max6916_write_reg(&spi->dev, int MAX6916_CONTROL_REG = 0x08, data);
> +
> +                       /*Enable the oscillator,disable the oscillator stop flag, and glitch filter to reduce current consumption*/
> +                       max6916_read_reg(&spi->dev, int MAX6916_STATUS_REG = 0X0C, &data);
> +                       data = data & MAX6916_REG_MAP_ADDRESS;
> +                       max6916_write_reg(&spi->dev, int MAX6916_STATUS_REG = 0x0C, data);

Return value ignored. Does not look correct.

> +
> +                       /* display the settings */
> +                       max6916_read_reg(&spi->dev, int MAX6916_CONTROL_REG = 0x08, &data);
> +                       dev_info(&spi->dev, "MAX6916 RTC CTRL Reg = 0x%02x\n", data);
> +
> +                       max6916_read_reg(&spi->dev, int MAX6916_STATUS_REG = 0X0C, &data);
> +                       dev_info(&spi->dev, "MAX6916 RTC Status Reg = 0x%02x\n", data);

dev_dbg()

> +
> +                       rtc = devm_rtc_device_register(&spi->dev, "max6916", &max6916_rtc_ops, THIS_MODULE);
> +
> +
> +                       if (IS_ERR(rtc))
> +                       return PTR_ERR(rtc);

What is wrong with this coding style?

> +
> +                       spi_set_drvdata(spi, rtc);
> +
> +                       return 0;
> +}
> +
> +static struct spi_driver max6916_driver = {
> +                       .driver = {
> +                       .name = "max6916",
> +                       },
> +                       .probe = max6916_probe,
> +};
> +
> +module_spi_driver(max6916_driver);
> +
> +MODULE_DESCRIPTION("MAX6916 SPI RTC DRIVER");
> +MODULE_AUTHOR("Venkat Prashanth B U <venkat.prashanth2498@gmail.com>");
> +MODULE_LICENSE("GPL v2");
> +
> +
> +
> +
> +
> +
> +
> +
> +

Did you look at the output after creating the patch? Please double
check what you are sending. These empty lines do not look meaningful.

Go to Documentation/SubmittingPatches and follow the guidelines. And
run checkpatch once again.

Best regards,
Krzysztof

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2016-05-13 16:05 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
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2016-05-13  6:14 [PATCH] rtc: add support for Maxim rtc max6916 v3.0 venkat.prashanth2498
2016-05-13 16:05 ` [rtc-linux] " Krzysztof Kozlowski

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