From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: rtc-linux@googlegroups.com MIME-Version: 1.0 Received: from mail-pf0-x236.google.com (mail-pf0-x236.google.com. [2607:f8b0:400e:c00::236]) by gmr-mx.google.com with ESMTPS id j129si91433oib.5.2017.11.26.22.48.49 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 26 Nov 2017 22:48:49 -0800 (PST) Received: by mail-pf0-x236.google.com with SMTP id q63so5648731pfd.7 for ; Sun, 26 Nov 2017 22:48:49 -0800 (PST) From: venkat.prashanth2498@gmail.com To: alexandre.belloni@free-electrons.com Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, a.zummo@towertech.it, Venkat Prashanth B U Subject: [rtc-linux] [PATCH] rtc: add support for maxim dallas ds1682 Date: Mon, 27 Nov 2017 12:18:44 +0530 Message-Id: <1511765324-3645-1-git-send-email-venkat.prashanth2498@gmail.com> Reply-To: rtc-linux@googlegroups.com Content-Type: text/plain; charset="UTF-8" List-ID: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , From: Venkat Prashanth B U Add supporting driver for Dallas Semiconductor DS1682 2 wire total elapsed time recorder. Signed-off-by: Venkat Prashanth B U --- drivers/rtc/rtc-ds1682.c | 284 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 284 insertions(+) diff --git a/drivers/rtc/rtc-ds1682.c b/drivers/rtc/rtc-ds1682.c index e69de29..a21c94d 100644 --- a/drivers/rtc/rtc-ds1682.c +++ b/drivers/rtc/rtc-ds1682.c @@ -0,0 +1,284 @@ +/* Driver for Dallas Semiconductor DS1682 2 wire total elapsed + * time recorder + * + * 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 +#include +#include +#include + +#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 "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ds1682"); -- 1.9.1 -- You received this message because you are subscribed to "rtc-linux". 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