linux-imx

/*

 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs

 *

 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>

 * Copyright (C) 2006 Tower Technologies

 * Copyright (C) 2008 Paul Mundt

 *

 * 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/rtc.h>

#include <linux/bcd.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/of_device.h>

​

/*

 * Ricoh has a family of I2C based RTCs, which differ only slightly from

 * each other.  Differences center on pinout (e.g. how many interrupts,

 * output clock, etc) and how the control registers are used.  The '372

 * is significant only because that's the one this driver first supported.

 */

#define RS5C372_REG_SECS    0

#define RS5C372_REG_MINS    1

#define RS5C372_REG_HOURS   2

#define RS5C372_REG_WDAY    3

#define RS5C372_REG_DAY     4

#define RS5C372_REG_MONTH   5

#define RS5C372_REG_YEAR    6

#define RS5C372_REG_TRIM    7

#   define RS5C372_TRIM_XSL     0x80

#   define RS5C372_TRIM_MASK    0x7F

​

#define RS5C_REG_ALARM_A_MIN    8           /* or ALARM_W */

#define RS5C_REG_ALARM_A_HOURS  9

#define RS5C_REG_ALARM_A_WDAY   10

​

#define RS5C_REG_ALARM_B_MIN    11          /* or ALARM_D */

#define RS5C_REG_ALARM_B_HOURS  12

#define RS5C_REG_ALARM_B_WDAY   13          /* (ALARM_B only) */

​

#define RS5C_REG_CTRL1      14

#   define RS5C_CTRL1_AALE      (1 << 7)    /* or WALE */

#   define RS5C_CTRL1_BALE      (1 << 6)    /* or DALE */

#   define RV5C387_CTRL1_24     (1 << 5)

#   define RS5C372A_CTRL1_SL1   (1 << 5)

#   define RS5C_CTRL1_CT_MASK   (7 << 0)

#   define RS5C_CTRL1_CT0       (0 << 0)    /* no periodic irq */

#   define RS5C_CTRL1_CT4       (4 << 0)    /* 1 Hz level irq */

#define RS5C_REG_CTRL2      15

#   define RS5C372_CTRL2_24     (1 << 5)

#   define RS5C_CTRL2_XSTP      (1 << 4)    /* only if !R2x2x */

#   define R2x2x_CTRL2_VDET     (1 << 6)    /* only if  R2x2x */

#   define R2x2x_CTRL2_XSTP     (1 << 5)    /* only if  R2x2x */

#   define R2x2x_CTRL2_PON      (1 << 4)    /* only if  R2x2x */

#   define RS5C_CTRL2_CTFG      (1 << 2)

#   define RS5C_CTRL2_AAFG      (1 << 1)    /* or WAFG */

#   define RS5C_CTRL2_BAFG      (1 << 0)    /* or DAFG */

​

​

/* to read (style 1) or write registers starting at R */

#define RS5C_ADDR(R)        (((R) << 4) | 0)

​

​

enum rtc_type {

    rtc_undef = 0,

    rtc_r2025sd,

    rtc_r2221tl,

    rtc_rs5c372a,

    rtc_rs5c372b,

    rtc_rv5c386,

    rtc_rv5c387a,

};

​

static const struct i2c_device_id rs5c372_id[] = {

    { "r2025sd", rtc_r2025sd },

    { "r2221tl", rtc_r2221tl },

    { "rs5c372a", rtc_rs5c372a },

    { "rs5c372b", rtc_rs5c372b },

    { "rv5c386", rtc_rv5c386 },

    { "rv5c387a", rtc_rv5c387a },

    { }

};

MODULE_DEVICE_TABLE(i2c, rs5c372_id);

​

static const struct of_device_id rs5c372_of_match[] = {

    {

        .compatible = "ricoh,r2025sd",

        .data = (void *)rtc_r2025sd