linux-imx

/*

 * An I2C and SPI driver for the NXP PCF2127/29 RTC

 * Copyright 2013 Til-Technologies

 *

 * Author: Renaud Cerrato <r.cerrato@til-technologies.fr>

 *

 * based on the other drivers in this same directory.

 *

 * Datasheet: http://cache.nxp.com/documents/data_sheet/PCF2127.pdf

 *

 * 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/i2c.h>

#include <linux/spi/spi.h>

#include <linux/bcd.h>

#include <linux/rtc.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/regmap.h>

​

#define PCF2127_REG_CTRL1       (0x00)  /* Control Register 1 */

#define PCF2127_REG_CTRL2       (0x01)  /* Control Register 2 */

​

#define PCF2127_REG_CTRL3       (0x02)  /* Control Register 3 */

#define PCF2127_REG_CTRL3_BLF       BIT(2)

​

#define PCF2127_REG_SC          (0x03)  /* datetime */

#define PCF2127_REG_MN          (0x04)

#define PCF2127_REG_HR          (0x05)

#define PCF2127_REG_DM          (0x06)

#define PCF2127_REG_DW          (0x07)

#define PCF2127_REG_MO          (0x08)

#define PCF2127_REG_YR          (0x09)

​

/* the pcf2127 has 512 bytes nvmem, pcf2129 doesn't */

#define PCF2127_REG_RAM_addr_MSB       0x1a

#define PCF2127_REG_RAM_wrt_cmd        0x1c

#define PCF2127_REG_RAM_rd_cmd         0x1d

​

#define PCF2127_OSF             BIT(7)  /* Oscillator Fail flag */

​

struct pcf2127 {

    struct rtc_device *rtc;

    struct regmap *regmap;

};

​

/*

 * In the routines that deal directly with the pcf2127 hardware, we use

 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.

 */

static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

    struct pcf2127 *pcf2127 = dev_get_drvdata(dev);

    unsigned char buf[10];

    int ret;

    int i;

​

    for (i = 0; i <= PCF2127_REG_CTRL3; i++) {

        ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1 + i,