From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 3 May 2016 14:09:41 +0200 From: Alexandre Belloni To: venkat.prashanth2498@gmail.com Cc: a.zummo@towertech.it, rtc-linux@googlegroups.com, inux-kernel@vger.kernel.org Subject: Re: [rtc-linux] [PATCH] rtc: add support for maxim rtc max6916 Message-ID: <20160503120941.GH2335@piout.net> References: <1462273240-2050-1-git-send-email-venkat.prashanth2498@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <1462273240-2050-1-git-send-email-venkat.prashanth2498@gmail.com> List-ID: Hi, Please use checkpatch before submitting. On 03/05/2016 at 04:00:40 -0700, venkat.prashanth2498@gmail.com wrote : > From: venkat-prashanth > > This is a patch to add support for > maxim rtc max6916 > > Signed-off-by:Venkat Prashanth B U > --- > --- > rtc-max6916.c | 157 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ This will not apply, that driver has to be in drivers/rtc > txtfile | 11 ++++ What is that file? > 2 files changed, 168 insertions(+) > create mode 100644 rtc-max6916.c > create mode 100644 txtfile > > diff --git a/rtc-max6916.c b/rtc-max6916.c > new file mode 100644 > index 0000000..7fabaa2 > --- /dev/null > +++ b/rtc-max6916.c > @@ -0,0 +1,157 @@ > +/* rtc-max6916.c > + * > + * Driver for MAXIM max6916 Low Current, SPI Compatible > + * Real Time Clock > + * > + * Author : Venkat Prashanth B U > + * > + * 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 > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* 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 0x00 > +#define ADDRESS_REG 0x70 > +#define DATA_REG 0x71 > +#define ADDRESS_REG_MASK 0xe0 > + > +static unsigned char get_rtc(unsigned char addr) > +{ > + outb(addr, ADDRESS_REG); > + return inb(DATA_REG); What is the use of those port IOs? > +} > + > +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 = get_rtc(buf[0]); > + dt->tm_min = get_rtc(buf[1]); > + dt->tm_hour = get_rtc(buf[2] & 0x00); How can that work? > + dt->tm_mday = get_rtc(buf[3]); > + dt->tm_mon = get_rtc(buf[4]) - 1; > + dt->tm_wday = get_rtc(buf[5]) - 1; > + dt->tm_year = get_rtc(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]; > + > + buf[0] = MAX6916_CLOCK_BURST & 0x7F; > + buf[1] = bcd2bin(dt->tm_sec); > + buf[2] = bcd2bin(dt->tm_min); > + buf[3] = (bcd2bin(dt->tm_hour) & 0x00); Same question, this is always setting 0... > + buf[4] = bcd2bin(dt->tm_mday); > + buf[5] = bcd2bin(dt->tm_mon + 1); > + buf[6] = bcd2bin(dt->tm_wday + 1); > + > + /* year in linux is from 1900 i.e in range of 100 > + in rtc it is from 00 to 99 */ > + dt->tm_year = dt->tm_year % 100; You should enforce the year range instead of accepting any value. > + > + buf[7] = bcd2bin(dt->tm_year); > + buf[8] = bcd2bin(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, MAX6916_CONTROL_REG, &data); > + data = data & ~(1<<7); > + max6916_write_reg(&spi->dev, MAX6916_CONTROL_REG, data); > + /* Enable the oscillator , disable the oscillator stop flag, > + and glitch filter to reduce current consumption */ > + max6916_read_reg(&spi->dev, MAX6916_STATUS_REG, &data); > + data = data & 0x1B; > + max6916_write_reg(&spi->dev, MAX6916_STATUS_REG, data); > + /* display the settings */ > + max6916_read_reg(&spi->dev, MAX6916_CONTROL_REG, &data); > + dev_info(&spi->dev, "MAX6916 RTC CTRL Reg = 0x%02x\n", data); > + max6916_read_reg(&spi->dev, MAX6916_STATUS_REG, &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, > +}; > +static void __exit rtc_exit(void) > +{ > + pr_info("rtc module unloaded\n"); > +} > + > +module_spi_driver(max6916_driver); > +MODULE_DESCRIPTION("MAX6916 SPI RTC DRIVER"); > +MODULE_AUTHOR("Venkat Prashanth B U "); > +MODULE_LICENSE("GPL v2"); > diff --git a/txtfile b/txtfile > new file mode 100644 > index 0000000..1604409 > --- /dev/null > +++ b/txtfile > @@ -0,0 +1,11 @@ > +config RTC_DRV_MAX6916 > +tristate "Maxim MAX6916" > + > +help > + If you say yes here you get support for the > + Maxim MAX6916 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‐max6916. Ok, this should go in drivers/rtc/Kconfig -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com