linux-imx

/*

 * Driver for Epson RTC-9701JE

 *

 * Copyright (C) 2008 Magnus Damm

 *

 * Based on rtc-max6902.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.

 */

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/platform_device.h>

#include <linux/device.h>

#include <linux/init.h>

#include <linux/rtc.h>

#include <linux/spi/spi.h>

#include <linux/bcd.h>

#include <linux/delay.h>

#include <linux/bitops.h>

​

#define RSECCNT 0x00    /* Second Counter */

#define RMINCNT 0x01    /* Minute Counter */

#define RHRCNT  0x02    /* Hour Counter */

#define RWKCNT  0x03    /* Week Counter */

#define RDAYCNT 0x04    /* Day Counter */

#define RMONCNT 0x05    /* Month Counter */

#define RYRCNT  0x06    /* Year Counter */

#define R100CNT 0x07    /* Y100 Counter */

#define RMINAR  0x08    /* Minute Alarm */

#define RHRAR   0x09    /* Hour Alarm */

#define RWKAR   0x0a    /* Week/Day Alarm */

#define RTIMCNT 0x0c    /* Interval Timer */

#define REXT    0x0d    /* Extension Register */

#define RFLAG   0x0e    /* RTC Flag Register */

#define RCR 0x0f    /* RTC Control Register */

​

static int write_reg(struct device *dev, int 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(spi, buf, ARRAY_SIZE(buf));

}

​

static int read_regs(struct device *dev, unsigned char *regs, int no_regs)

{

    struct spi_device *spi = to_spi_device(dev);

    u8 txbuf[1], rxbuf[1];

    int k, ret;

​

    ret = 0;

​

    for (k = 0; ret == 0 && k < no_regs; k++) {

        txbuf[0] = 0x80 | regs[k];