[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 <raph@raphnet.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Raphael Assenat
Linus Torvalds
parent
9be05b57bd
commit
362600fe60
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@ -227,4 +227,14 @@ config RTC_DRV_MAX6902
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This driver can also be built as a module. If so, the module
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will be called rtc-max6902.
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config RTC_DRV_V3020
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tristate "EM Microelectronic V3020"
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depends on RTC_CLASS
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help
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If you say yes here you will get support for the
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EM Microelectronic v3020 RTC chip.
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This driver can also be built as a module. If so, the module
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will be called rtc-v3020.
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endmenu
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@ -24,3 +24,4 @@ obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o
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obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o
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obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
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obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o
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obj-$(CONFIG_RTC_DRV_V3020) += rtc-v3020.o
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@ -0,0 +1,264 @@
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/* drivers/rtc/rtc-v3020.c
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*
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* Copyright (C) 2006 8D Technologies inc.
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* Copyright (C) 2004 Compulab Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Driver for the V3020 RTC
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*
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* Changelog:
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*
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* 10-May-2006: Raphael Assenat <raph@8d.com>
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* - Converted to platform driver
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* - Use the generic rtc class
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*
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* ??-???-2004: Someone at Compulab
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* - Initial driver creation.
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*
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*/
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#include <linux/platform_device.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/rtc.h>
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#include <linux/types.h>
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#include <linux/bcd.h>
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#include <linux/rtc-v3020.h>
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#include <asm/io.h>
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#undef DEBUG
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struct v3020 {
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void __iomem *ioaddress;
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int leftshift;
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struct rtc_device *rtc;
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};
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static void v3020_set_reg(struct v3020 *chip, unsigned char address,
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unsigned char data)
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{
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int i;
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unsigned char tmp;
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tmp = address;
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for (i = 0; i < 4; i++) {
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writel((tmp & 1) << chip->leftshift, chip->ioaddress);
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tmp >>= 1;
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}
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/* Commands dont have data */
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if (!V3020_IS_COMMAND(address)) {
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for (i = 0; i < 8; i++) {
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writel((data & 1) << chip->leftshift, chip->ioaddress);
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data >>= 1;
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}
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}
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}
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static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address)
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{
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unsigned int data=0;
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int i;
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for (i = 0; i < 4; i++) {
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writel((address & 1) << chip->leftshift, chip->ioaddress);
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address >>= 1;
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}
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for (i = 0; i < 8; i++) {
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data >>= 1;
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if (readl(chip->ioaddress) & (1 << chip->leftshift))
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data |= 0x80;
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}
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return data;
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}
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static int v3020_read_time(struct device *dev, struct rtc_time *dt)
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{
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struct v3020 *chip = dev_get_drvdata(dev);
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int tmp;
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/* Copy the current time to ram... */
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v3020_set_reg(chip, V3020_CMD_CLOCK2RAM, 0);
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/* ...and then read constant values. */
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tmp = v3020_get_reg(chip, V3020_SECONDS);
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dt->tm_sec = BCD2BIN(tmp);
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tmp = v3020_get_reg(chip, V3020_MINUTES);
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dt->tm_min = BCD2BIN(tmp);
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tmp = v3020_get_reg(chip, V3020_HOURS);
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dt->tm_hour = BCD2BIN(tmp);
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tmp = v3020_get_reg(chip, V3020_MONTH_DAY);
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dt->tm_mday = BCD2BIN(tmp);
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tmp = v3020_get_reg(chip, V3020_MONTH);
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dt->tm_mon = BCD2BIN(tmp);
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tmp = v3020_get_reg(chip, V3020_WEEK_DAY);
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dt->tm_wday = BCD2BIN(tmp);
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tmp = v3020_get_reg(chip, V3020_YEAR);
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dt->tm_year = BCD2BIN(tmp)+100;
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#ifdef DEBUG
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printk("\n%s : Read RTC values\n",__FUNCTION__);
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printk("tm_hour: %i\n",dt->tm_hour);
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printk("tm_min : %i\n",dt->tm_min);
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printk("tm_sec : %i\n",dt->tm_sec);
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printk("tm_year: %i\n",dt->tm_year);
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printk("tm_mon : %i\n",dt->tm_mon);
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printk("tm_mday: %i\n",dt->tm_mday);
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printk("tm_wday: %i\n",dt->tm_wday);
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#endif
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return 0;
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}
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static int v3020_set_time(struct device *dev, struct rtc_time *dt)
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{
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struct v3020 *chip = dev_get_drvdata(dev);
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#ifdef DEBUG
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printk("\n%s : Setting RTC values\n",__FUNCTION__);
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printk("tm_sec : %i\n",dt->tm_sec);
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printk("tm_min : %i\n",dt->tm_min);
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printk("tm_hour: %i\n",dt->tm_hour);
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printk("tm_mday: %i\n",dt->tm_mday);
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printk("tm_wday: %i\n",dt->tm_wday);
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printk("tm_year: %i\n",dt->tm_year);
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#endif
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/* Write all the values to ram... */
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v3020_set_reg(chip, V3020_SECONDS, BIN2BCD(dt->tm_sec));
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v3020_set_reg(chip, V3020_MINUTES, BIN2BCD(dt->tm_min));
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v3020_set_reg(chip, V3020_HOURS, BIN2BCD(dt->tm_hour));
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v3020_set_reg(chip, V3020_MONTH_DAY, BIN2BCD(dt->tm_mday));
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v3020_set_reg(chip, V3020_MONTH, BIN2BCD(dt->tm_mon));
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v3020_set_reg(chip, V3020_WEEK_DAY, BIN2BCD(dt->tm_wday));
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v3020_set_reg(chip, V3020_YEAR, BIN2BCD(dt->tm_year % 100));
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/* ...and set the clock. */
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v3020_set_reg(chip, V3020_CMD_RAM2CLOCK, 0);
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/* Compulab used this delay here. I dont know why,
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* the datasheet does not specify a delay. */
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/*mdelay(5);*/
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return 0;
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}
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static struct rtc_class_ops v3020_rtc_ops = {
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.read_time = v3020_read_time,
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.set_time = v3020_set_time,
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};
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static int rtc_probe(struct platform_device *pdev)
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{
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struct v3020_platform_data *pdata = pdev->dev.platform_data;
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struct v3020 *chip;
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struct rtc_device *rtc;
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int retval = -EBUSY;
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int i;
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int temp;
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if (pdev->num_resources != 1)
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return -EBUSY;
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if (pdev->resource[0].flags != IORESOURCE_MEM)
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return -EBUSY;
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if (pdev == NULL)
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return -EBUSY;
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chip = kzalloc(sizeof *chip, GFP_KERNEL);
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if (!chip)
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return -ENOMEM;
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chip->leftshift = pdata->leftshift;
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chip->ioaddress = ioremap(pdev->resource[0].start, 1);
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if (chip->ioaddress == NULL)
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goto err_chip;
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/* Make sure the v3020 expects a communication cycle
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* by reading 8 times */
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for (i = 0; i < 8; i++)
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temp = readl(chip->ioaddress);
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/* Test chip by doing a write/read sequence
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* to the chip ram */
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v3020_set_reg(chip, V3020_SECONDS, 0x33);
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if(v3020_get_reg(chip, V3020_SECONDS) != 0x33) {
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retval = -ENODEV;
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goto err_io;
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}
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/* Make sure frequency measurment mode, test modes, and lock
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* are all disabled */
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v3020_set_reg(chip, V3020_STATUS_0, 0x0);
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dev_info(&pdev->dev, "Chip available at physical address 0x%p,"
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"data connected to D%d\n",
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(void*)pdev->resource[0].start,
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chip->leftshift);
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platform_set_drvdata(pdev, chip);
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rtc = rtc_device_register("v3020",
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&pdev->dev, &v3020_rtc_ops, THIS_MODULE);
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if (IS_ERR(rtc)) {
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retval = PTR_ERR(rtc);
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goto err_io;
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}
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chip->rtc = rtc;
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return 0;
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err_io:
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iounmap(chip->ioaddress);
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err_chip:
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kfree(chip);
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return retval;
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}
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static int rtc_remove(struct platform_device *dev)
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{
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struct v3020 *chip = platform_get_drvdata(dev);
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struct rtc_device *rtc = chip->rtc;
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if (rtc)
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rtc_device_unregister(rtc);
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iounmap(chip->ioaddress);
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kfree(chip);
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return 0;
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}
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static struct platform_driver rtc_device_driver = {
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.probe = rtc_probe,
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.remove = rtc_remove,
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.driver = {
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.name = "v3020",
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.owner = THIS_MODULE,
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},
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};
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static __init int v3020_init(void)
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{
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return platform_driver_register(&rtc_device_driver);
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}
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static __exit void v3020_exit(void)
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{
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platform_driver_unregister(&rtc_device_driver);
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}
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module_init(v3020_init);
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module_exit(v3020_exit);
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MODULE_DESCRIPTION("V3020 RTC");
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MODULE_AUTHOR("Raphael Assenat");
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MODULE_LICENSE("GPL");
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@ -0,0 +1,35 @@
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/*
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* v3020.h - Registers definition and platform data structure for the v3020 RTC.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2006, 8D Technologies inc.
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*/
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#ifndef __LINUX_V3020_H
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#define __LINUX_V3020_H
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/* The v3020 has only one data pin but which one
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* is used depends on the board. */
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struct v3020_platform_data {
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int leftshift; /* (1<<(leftshift)) & readl() */
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};
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#define V3020_STATUS_0 0x00
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#define V3020_STATUS_1 0x01
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#define V3020_SECONDS 0x02
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#define V3020_MINUTES 0x03
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#define V3020_HOURS 0x04
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#define V3020_MONTH_DAY 0x05
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#define V3020_MONTH 0x06
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#define V3020_YEAR 0x07
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#define V3020_WEEK_DAY 0x08
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#define V3020_WEEK 0x09
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#define V3020_IS_COMMAND(val) ((val)>=0x0E)
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#define V3020_CMD_RAM2CLOCK 0x0E
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#define V3020_CMD_CLOCK2RAM 0x0F
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#endif /* __LINUX_V3020_H */
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