Hi, Please run checkpatch --strict before submitting.
Also, it seems to me this is a regular i2c chip, I don't think the whole bitbanging is necessary. On 24/12/2016 at 08:47:14 -0800, Venkat Prashanth B U wrote: > This is a patch to add support for > maxim dallas ds1682 total elapsed time recorder > > Signed‐off‐by: Venkat Prashanth B U <[email protected]> > --- > --- > drivers/rtc/Kconfig | 9 ++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-ds1682.c | 288 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 298 insertions(+) > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index e859d14..bcab91f 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -275,6 +275,15 @@ config RTC_DRV_DS1672 > This driver can also be built as a module. If so, the module > will be called rtc-ds1672. > > +config RTC_DRV_DS1682 > + tristate "Dallas/Maxim DS1682" > + help > + If you say yes here you get support for the > + Dallas/Maxim DS1682 total elapsed time recorder. > + > + This driver can also be built as a module. If so, the module > + will be called rtc-ds1682. > + > config RTC_DRV_HYM8563 > tristate "Haoyu Microelectronics HYM8563" > depends on OF > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index 1ac694a..70bb28c 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -58,6 +58,7 @@ 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 > +obj-$(CONFIG_RTC_DRV_DS1682) += rtc-ds1682.o > obj-$(CONFIG_RTC_DRV_DS1685_FAMILY) += rtc-ds1685.o > obj-$(CONFIG_RTC_DRV_DS1742) += rtc-ds1742.o > obj-$(CONFIG_RTC_DRV_DS2404) += rtc-ds2404.o > diff --git a/drivers/rtc/rtc-ds1682.c b/drivers/rtc/rtc-ds1682.c > index e69de29..fad440e 100644 > --- a/drivers/rtc/rtc-ds1682.c > +++ b/drivers/rtc/rtc-ds1682.c > @@ -0,0 +1,288 @@ > +/* Driver for Dallas Semiconductor DS1682 2 wire total elapsed > + * time recorder > + * > + * Author : Venkat Prashanth B U <[email protected]> > + * > + * 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/platform_device.h> > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/rtc.h> > +#include <linux/types.h> > +#include <linux/bcd.h> > +#include <linux/delay.h> > +#include <linux/gpio.h> > +#include <linux/slab.h> > + > +#include <linux/io.h> > + > +#define DS1682_READ_MEMORY_CMD 0x1D > + > +#ifndef __LINUX_DS1682_H > +#define __LINUX_DS1682_H > + > +const struct ds1682_platform_data { > + > + > + unsigned int gpio_rst; > + unsigned int gpio_clk; > + unsigned int gpio_dq; > +}; > +#endif > + > +const struct ds1682; > + > +const struct ds1682_chip_ops { > + int (*map_io)(const struct ds1682 *chip, struct platform_device *pdev, > + const struct ds1682_platform_data *pdata); > + void (*unmap_io)(const struct ds1682 *chip); > +}; > + > +#define DS1682_RST 0 > +#define DS1682_CLK 1 > +#define DS1682_DQ 2 > + > +const struct ds1682_gpio { > + const char *name; > + unsigned int gpio; > +}; > + > +const struct ds1682 { > + const struct ds1682_gpio *gpio; > + const struct ds1682_chip_ops *ops; > + const struct rtc_device *rtc; > +}; > + > +const struct ds1682_gpio ds1682_gpio[] = { > + { "RTC RST", 0 }, > + { "RTC CLK", 0 }, > + { "RTC DQ", 0 }, > +}; > + > +int ds1682_gpio_map(const struct ds1682 *chip, struct platform_device *pdev, > + const struct ds1682_platform_data *pdata) > +{ > + int i, err; > + > + ds1682_gpio[DS1682_RST].gpio = pdata->gpio_rst; > + ds1682_gpio[DS1682_CLK].gpio = pdata->gpio_clk; > + ds1682_gpio[DS1682_DQ].gpio = pdata->gpio_dq; > + > + for (i = 0; i < ARRAY_SIZE(ds1682_gpio); i++) { > + err = gpio_request(ds1682_gpio[i].gpio, ds1682_gpio[i].name); > + if (err) { > + dev_err(&pdev->dev, "error mapping gpio %s: %d\n", > + ds1682_gpio[i].name, err); > + goto err_request; > + } > + if (i != DS1682_DQ) > + gpio_direction_output(ds1682_gpio[i].gpio, 1); > + } > + > + chip->gpio = ds1682_gpio; > + return 0; > + > +err_request: > + while (--i >= 0) > + gpio_free(ds1682_gpio[i].gpio); > + return err; > +} > + > +static void ds1682_gpio_unmap(const struct ds1682 *chip) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(ds1682_gpio); i++) > + gpio_free(ds1682_gpio[i].gpio); > +} > + > +static const struct ds1682_chip_ops ds1682_gpio_ops = { > + .map_io = ds1682_gpio_map, > + .unmap_io = ds1682_gpio_unmap, > +}; > + > +static void ds1682_reset(const struct device *dev) > +{ > + gpio_set_value(ds1682_gpio[DS1682_RST].gpio, 0); > + udelay(1000); > + gpio_set_value(ds1682_gpio[DS1682_RST].gpio, 1); > + gpio_set_value(ds1682_gpio[DS1682_CLK].gpio, 0); > + gpio_direction_output(ds1682_gpio[DS1682_DQ].gpio, 0); > + udelay(10); > +} > + > +static void ds1682_write_byte(const struct device *dev, u8 byte) > +{ > + int i; > + > + gpio_direction_output(ds1682_gpio[DS1682_DQ].gpio, 1); > + for (i = 0; i < 8; i++) { > + gpio_set_value(ds1682_gpio[DS1682_DQ].gpio, byte & (1 << i)); > + udelay(10); > + gpio_set_value(ds1682_gpio[DS1682_CLK].gpio, 1); > + udelay(10); > + gpio_set_value(ds1682_gpio[DS1682_CLK].gpio, 0); > + udelay(10); > + } > +} > + > +static u8 ds1682_read_byte(const struct device *dev) > +{ > + int i; > + u8 ret = 0; > + > + gpio_direction_input(ds1682_gpio[DS1682_DQ].gpio); > + > + for (i = 0; i < 8; i++) { > + gpio_set_value(ds1682_gpio[DS1682_CLK].gpio, 0); > + udelay(10); > + if (gpio_get_value(ds1682_gpio[DS1682_DQ].gpio)) > + ret |= 1 << i; > + gpio_set_value(ds1682_gpio[DS1682_CLK].gpio, 1); > + udelay(10); > + } > + return ret; > +} > + > +static void ds1682_read_memory(const struct device *dev, u16 offset, > + int length, u8 *out) > +{ > + ds1682_reset(dev); > + ds1682_write_byte(dev, DS1682_READ_MEMORY_CMD); > + ds1682_write_byte(dev, offset & 0xff); > + ds1682_write_byte(dev, (offset >> 8) & 0xff); > + while (length--) > + *out++ = ds1682_read_byte(dev); > +} > + > +static void ds1682_write_memory(const struct device *dev, u16 offset, > + int length, u8 *out) > +{ > + int i; > + u8 ta01, ta02, es; > + > + ds1682_reset(dev); > + ds1682_write_byte(dev, offset & 0xff); > + ds1682_write_byte(dev, (offset >> 8) & 0xff); > + > + for (i = 0; i < length; i++) > + ds1682_write_byte(dev, out[i]); > + > + ds1682_reset(dev); > + > + ta01 = ds1682_read_byte(dev); > + ta02 = ds1682_read_byte(dev); > + es = ds1682_read_byte(dev); > + > + for (i = 0; i < length; i++) { > + if (out[i] != ds1682_read_byte(dev)) { > + dev_err(dev, "read invalid data\n"); > + return; > + } > + } > + > + ds1682_reset(dev); > + ds1682_write_byte(dev, ta01); > + ds1682_write_byte(dev, ta02); > + ds1682_write_byte(dev, es); > + gpio_direction_input(ds1682_gpio[DS1682_DQ].gpio); > + while (gpio_get_value(ds1682_gpio[DS1682_DQ].gpio)) > + ; > +} > + > +static void ds1682_enable_osc(const struct device *dev) > +{ > + u8 in[1] = { 0x10 }; /* enable oscillator */ > + > + ds1682_write_memory(dev, 0x201, 1, in); > +} > + > +static int ds1682_read_time(const struct device *dev, struct rtc_time *dt) > +{ > + unsigned long time = 0; > + > + ds1682_read_memory(dev, 0x203, 4, (u8 *)&time); > + time = le32_to_cpu(time); > + rtc_time_to_tm(time, dt); > + return rtc_valid_tm(dt); > +} > + > +static int ds1682_set_mmss(const struct device *dev, unsigned long secs) > +{ > + u32 time = cpu_to_le32(secs); > + > + ds1682_write_memory(dev, 0x203, 4, (u8 *)&time); > + return 0; > +} > + > +static const struct rtc_class_ops ds1682_rtc_ops = { > + .read_time = ds1682_read_time, > + .set_mmss = ds1682_set_mmss, > +}; > + > +static int rtc_probe(const struct platform_device *pdev) > +{ > +const struct ds1682_platform_data *pdata = dev_get_platdata(&pdev->dev); > + const struct ds1682 *chip; > + int retval = -EBUSY; > + > +chip = devm_kzalloc(&pdev->dev, sizeof(const struct ds1682), GFP_KERNEL); > + if (!chip) > + return -ENOMEM; > + > + chip->ops = &ds1682_gpio_ops; > + > + retval = chip->ops->map_io(chip, pdev, pdata); > + if (retval) > + goto err_chip; > + > + dev_info(&pdev->dev, "using GPIOs RST:%d, CLK:%d, DQ:%d\n", > + chip->gpio[DS1682_RST].gpio, chip->gpio[DS1682_CLK].gpio, > + chip->gpio[DS1682_DQ].gpio); > + > + platform_set_drvdata(pdev, chip); > + > + chip->rtc = devm_rtc_device_register(&pdev->dev, "ds1682", > + &ds1682_rtc_ops, THIS_MODULE); > + if (IS_ERR(chip->rtc)) { > + retval = PTR_ERR(chip->rtc); > + goto err_io; > + } > + > + ds1682_enable_osc(&pdev->dev); > + return 0; > + > +err_io: > + chip->ops->unmap_io(chip); > +err_chip: > + return retval; > +} > + > +static int rtc_remove(const struct platform_device *dev) > +{ > +const struct ds1682 *chip = platform_get_drvdata(dev); > + > + chip->ops->unmap_io(chip); > + > + return 0; > +} > + > +const struct platform_driver rtc_device_driver = { > + .probe = rtc_probe, > + .remove = rtc_remove, > + .driver = { > + .name = "ds1682", > + }, > +}; > +module_platform_driver(rtc_device_driver); > + > +MODULE_DESCRIPTION("DS1682 Total Elapsed Time Recorder"); > +MODULE_AUTHOR("Venkat Prashanth B U <[email protected]>"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("platform:ds1682"); > + > -- > 1.9.2 > -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
