linux-imx

// SPDX-License-Identifier: GPL-2.0+

//

// Copyright (c) 2013-2014 Samsung Electronics Co., Ltd

//  http://www.samsung.com

//

//  Copyright (C) 2013 Google, Inc

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/module.h>

#include <linux/i2c.h>

#include <linux/bcd.h>

#include <linux/regmap.h>

#include <linux/rtc.h>

#include <linux/platform_device.h>

#include <linux/mfd/samsung/core.h>

#include <linux/mfd/samsung/irq.h>

#include <linux/mfd/samsung/rtc.h>

#include <linux/mfd/samsung/s2mps14.h>

​

/*

 * Maximum number of retries for checking changes in UDR field

 * of S5M_RTC_UDR_CON register (to limit possible endless loop).

 *

 * After writing to RTC registers (setting time or alarm) read the UDR field

 * in S5M_RTC_UDR_CON register. UDR is auto-cleared when data have

 * been transferred.

 */

#define UDR_READ_RETRY_CNT  5

​

enum {

    RTC_SEC = 0,

    RTC_MIN,

    RTC_HOUR,

    RTC_WEEKDAY,

    RTC_DATE,

    RTC_MONTH,

    RTC_YEAR1,

    RTC_YEAR2,

    /* Make sure this is always the last enum name. */

    RTC_MAX_NUM_TIME_REGS

};

​

/*

 * Registers used by the driver which are different between chipsets.

 *

 * Operations like read time and write alarm/time require updating

 * specific fields in UDR register. These fields usually are auto-cleared

 * (with some exceptions).

 *

 * Table of operations per device:

 *

 * Device     | Write time | Read time | Write alarm

 * =================================================

 * S5M8767    | UDR + TIME |           | UDR

 * S2MPS11/14 | WUDR       | RUDR      | WUDR + RUDR

 * S2MPS13    | WUDR       | RUDR      | WUDR + AUDR

 * S2MPS15    | WUDR       | RUDR      | AUDR

 */

struct s5m_rtc_reg_config {

    /* Number of registers used for setting time/alarm0/alarm1 */

    unsigned int regs_count;

    /* First register for time, seconds */

    unsigned int time;

    /* RTC control register */

    unsigned int ctrl;

    /* First register for alarm 0, seconds */

    unsigned int alarm0;

    /* First register for alarm 1, seconds */

    unsigned int alarm1;

    /*

     * Register for update flag (UDR). Typically setting UDR field to 1

     * will enable update of time or alarm register. Then it will be

     * auto-cleared after successful update.

     */

    unsigned int udr_update;

    /* Auto-cleared mask in UDR field for writing time and alarm */

    unsigned int autoclear_udr_mask;

    /*

     * Masks in UDR field for time and alarm operations.

     * The read time mask can be 0. Rest should not.

     */

    unsigned int read_time_udr_mask;

    unsigned int write_time_udr_mask;

    unsigned int write_alarm_udr_mask;

};

​

/* Register map for S5M8763 and S5M8767 */

static const struct s5m_rtc_reg_config s5m_rtc_regs = {

    .regs_count     = 8,

    .time           = S5M_RTC_SEC,

    .ctrl           = S5M_ALARM1_CONF,