From: Raphael Assenat Date: Sun, 25 Jun 2006 12:48:24 +0000 (-0700) Subject: [PATCH] Add v3020 RTC support X-Git-Tag: v2.6.18-rc1~950 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=362600fe60fd18a25b4de8ec544b9e24e77e1484;p=linux-2.6 [PATCH] Add v3020 RTC support This patch adds support for the v3020 RTC from EM Microelectronic. The v3020 RTC is designed to be connected on a bus using only one data bit. Since any data bit may be used, it is necessary to specify this to the driver by passing a struct v3020_platform_data pointer (see include/linux/rtc-v3020.h) to the driver. Part of the following code comes from the kernel patchs produced by Compulab for their products. The original file (available here: http://raph.people.8d.com/misc/emv3020.c) was released under the terms of the GPL license. [akpm@osdl.org: cleanups] Signed-off-by: Raphael Assenat Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 94746cfac7..8534012ebd 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -227,4 +227,14 @@ config RTC_DRV_MAX6902 This driver can also be built as a module. If so, the module will be called rtc-max6902. +config RTC_DRV_V3020 + tristate "EM Microelectronic V3020" + depends on RTC_CLASS + help + If you say yes here you will get support for the + EM Microelectronic v3020 RTC chip. + + This driver can also be built as a module. If so, the module + will be called rtc-v3020. + endmenu diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index dd480d6bcd..cbb8e8a7f6 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -24,3 +24,4 @@ obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o +obj-$(CONFIG_RTC_DRV_V3020) += rtc-v3020.o diff --git a/drivers/rtc/rtc-v3020.c b/drivers/rtc/rtc-v3020.c new file mode 100644 index 0000000000..a40f400acf --- /dev/null +++ b/drivers/rtc/rtc-v3020.c @@ -0,0 +1,264 @@ +/* drivers/rtc/rtc-v3020.c + * + * Copyright (C) 2006 8D Technologies inc. + * Copyright (C) 2004 Compulab Ltd. + * + * 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. + * + * Driver for the V3020 RTC + * + * Changelog: + * + * 10-May-2006: Raphael Assenat + * - Converted to platform driver + * - Use the generic rtc class + * + * ??-???-2004: Someone at Compulab + * - Initial driver creation. + * + */ +#include +#include +#include +#include +#include +#include +#include + +#include + +#undef DEBUG + +struct v3020 { + void __iomem *ioaddress; + int leftshift; + struct rtc_device *rtc; +}; + +static void v3020_set_reg(struct v3020 *chip, unsigned char address, + unsigned char data) +{ + int i; + unsigned char tmp; + + tmp = address; + for (i = 0; i < 4; i++) { + writel((tmp & 1) << chip->leftshift, chip->ioaddress); + tmp >>= 1; + } + + /* Commands dont have data */ + if (!V3020_IS_COMMAND(address)) { + for (i = 0; i < 8; i++) { + writel((data & 1) << chip->leftshift, chip->ioaddress); + data >>= 1; + } + } +} + +static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address) +{ + unsigned int data=0; + int i; + + for (i = 0; i < 4; i++) { + writel((address & 1) << chip->leftshift, chip->ioaddress); + address >>= 1; + } + + for (i = 0; i < 8; i++) { + data >>= 1; + if (readl(chip->ioaddress) & (1 << chip->leftshift)) + data |= 0x80; + } + + return data; +} + +static int v3020_read_time(struct device *dev, struct rtc_time *dt) +{ + struct v3020 *chip = dev_get_drvdata(dev); + int tmp; + + /* Copy the current time to ram... */ + v3020_set_reg(chip, V3020_CMD_CLOCK2RAM, 0); + + /* ...and then read constant values. */ + tmp = v3020_get_reg(chip, V3020_SECONDS); + dt->tm_sec = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_MINUTES); + dt->tm_min = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_HOURS); + dt->tm_hour = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_MONTH_DAY); + dt->tm_mday = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_MONTH); + dt->tm_mon = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_WEEK_DAY); + dt->tm_wday = BCD2BIN(tmp); + tmp = v3020_get_reg(chip, V3020_YEAR); + dt->tm_year = BCD2BIN(tmp)+100; + +#ifdef DEBUG + printk("\n%s : Read RTC values\n",__FUNCTION__); + printk("tm_hour: %i\n",dt->tm_hour); + printk("tm_min : %i\n",dt->tm_min); + printk("tm_sec : %i\n",dt->tm_sec); + printk("tm_year: %i\n",dt->tm_year); + printk("tm_mon : %i\n",dt->tm_mon); + printk("tm_mday: %i\n",dt->tm_mday); + printk("tm_wday: %i\n",dt->tm_wday); +#endif + + return 0; +} + + +static int v3020_set_time(struct device *dev, struct rtc_time *dt) +{ + struct v3020 *chip = dev_get_drvdata(dev); + +#ifdef DEBUG + printk("\n%s : Setting RTC values\n",__FUNCTION__); + printk("tm_sec : %i\n",dt->tm_sec); + printk("tm_min : %i\n",dt->tm_min); + printk("tm_hour: %i\n",dt->tm_hour); + printk("tm_mday: %i\n",dt->tm_mday); + printk("tm_wday: %i\n",dt->tm_wday); + printk("tm_year: %i\n",dt->tm_year); +#endif + + /* Write all the values to ram... */ + v3020_set_reg(chip, V3020_SECONDS, BIN2BCD(dt->tm_sec)); + v3020_set_reg(chip, V3020_MINUTES, BIN2BCD(dt->tm_min)); + v3020_set_reg(chip, V3020_HOURS, BIN2BCD(dt->tm_hour)); + v3020_set_reg(chip, V3020_MONTH_DAY, BIN2BCD(dt->tm_mday)); + v3020_set_reg(chip, V3020_MONTH, BIN2BCD(dt->tm_mon)); + v3020_set_reg(chip, V3020_WEEK_DAY, BIN2BCD(dt->tm_wday)); + v3020_set_reg(chip, V3020_YEAR, BIN2BCD(dt->tm_year % 100)); + + /* ...and set the clock. */ + v3020_set_reg(chip, V3020_CMD_RAM2CLOCK, 0); + + /* Compulab used this delay here. I dont know why, + * the datasheet does not specify a delay. */ + /*mdelay(5);*/ + + return 0; +} + +static struct rtc_class_ops v3020_rtc_ops = { + .read_time = v3020_read_time, + .set_time = v3020_set_time, +}; + +static int rtc_probe(struct platform_device *pdev) +{ + struct v3020_platform_data *pdata = pdev->dev.platform_data; + struct v3020 *chip; + struct rtc_device *rtc; + int retval = -EBUSY; + int i; + int temp; + + if (pdev->num_resources != 1) + return -EBUSY; + + if (pdev->resource[0].flags != IORESOURCE_MEM) + return -EBUSY; + + if (pdev == NULL) + return -EBUSY; + + chip = kzalloc(sizeof *chip, GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->leftshift = pdata->leftshift; + chip->ioaddress = ioremap(pdev->resource[0].start, 1); + if (chip->ioaddress == NULL) + goto err_chip; + + /* Make sure the v3020 expects a communication cycle + * by reading 8 times */ + for (i = 0; i < 8; i++) + temp = readl(chip->ioaddress); + + /* Test chip by doing a write/read sequence + * to the chip ram */ + v3020_set_reg(chip, V3020_SECONDS, 0x33); + if(v3020_get_reg(chip, V3020_SECONDS) != 0x33) { + retval = -ENODEV; + goto err_io; + } + + /* Make sure frequency measurment mode, test modes, and lock + * are all disabled */ + v3020_set_reg(chip, V3020_STATUS_0, 0x0); + + dev_info(&pdev->dev, "Chip available at physical address 0x%p," + "data connected to D%d\n", + (void*)pdev->resource[0].start, + chip->leftshift); + + platform_set_drvdata(pdev, chip); + + rtc = rtc_device_register("v3020", + &pdev->dev, &v3020_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc)) { + retval = PTR_ERR(rtc); + goto err_io; + } + chip->rtc = rtc; + + return 0; + +err_io: + iounmap(chip->ioaddress); +err_chip: + kfree(chip); + + return retval; +} + +static int rtc_remove(struct platform_device *dev) +{ + struct v3020 *chip = platform_get_drvdata(dev); + struct rtc_device *rtc = chip->rtc; + + if (rtc) + rtc_device_unregister(rtc); + + iounmap(chip->ioaddress); + kfree(chip); + + return 0; +} + +static struct platform_driver rtc_device_driver = { + .probe = rtc_probe, + .remove = rtc_remove, + .driver = { + .name = "v3020", + .owner = THIS_MODULE, + }, +}; + +static __init int v3020_init(void) +{ + return platform_driver_register(&rtc_device_driver); +} + +static __exit void v3020_exit(void) +{ + platform_driver_unregister(&rtc_device_driver); +} + +module_init(v3020_init); +module_exit(v3020_exit); + +MODULE_DESCRIPTION("V3020 RTC"); +MODULE_AUTHOR("Raphael Assenat"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/rtc-v3020.h b/include/linux/rtc-v3020.h new file mode 100644 index 0000000000..bf74e63c98 --- /dev/null +++ b/include/linux/rtc-v3020.h @@ -0,0 +1,35 @@ +/* + * v3020.h - Registers definition and platform data structure for the v3020 RTC. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2006, 8D Technologies inc. + */ +#ifndef __LINUX_V3020_H +#define __LINUX_V3020_H + +/* The v3020 has only one data pin but which one + * is used depends on the board. */ +struct v3020_platform_data { + int leftshift; /* (1<<(leftshift)) & readl() */ +}; + +#define V3020_STATUS_0 0x00 +#define V3020_STATUS_1 0x01 +#define V3020_SECONDS 0x02 +#define V3020_MINUTES 0x03 +#define V3020_HOURS 0x04 +#define V3020_MONTH_DAY 0x05 +#define V3020_MONTH 0x06 +#define V3020_YEAR 0x07 +#define V3020_WEEK_DAY 0x08 +#define V3020_WEEK 0x09 + +#define V3020_IS_COMMAND(val) ((val)>=0x0E) + +#define V3020_CMD_RAM2CLOCK 0x0E +#define V3020_CMD_CLOCK2RAM 0x0F + +#endif /* __LINUX_V3020_H */