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|
/*
* Micro Crystal RV-3029 rtc class driver
*
* Author: Gregory Hermant <gregory.hermant@calao-systems.com>
* Michael Buesch <m@bues.ch>
*
* based on previously existing rtc class drivers
*
* 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/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
/* Register map */
/* control section */
#define RV3029_ONOFF_CTRL 0x00
#define RV3029_ONOFF_CTRL_WE BIT(0)
#define RV3029_ONOFF_CTRL_TE BIT(1)
#define RV3029_ONOFF_CTRL_TAR BIT(2)
#define RV3029_ONOFF_CTRL_EERE BIT(3)
#define RV3029_ONOFF_CTRL_SRON BIT(4)
#define RV3029_ONOFF_CTRL_TD0 BIT(5)
#define RV3029_ONOFF_CTRL_TD1 BIT(6)
#define RV3029_ONOFF_CTRL_CLKINT BIT(7)
#define RV3029_IRQ_CTRL 0x01
#define RV3029_IRQ_CTRL_AIE BIT(0)
#define RV3029_IRQ_CTRL_TIE BIT(1)
#define RV3029_IRQ_CTRL_V1IE BIT(2)
#define RV3029_IRQ_CTRL_V2IE BIT(3)
#define RV3029_IRQ_CTRL_SRIE BIT(4)
#define RV3029_IRQ_FLAGS 0x02
#define RV3029_IRQ_FLAGS_AF BIT(0)
#define RV3029_IRQ_FLAGS_TF BIT(1)
#define RV3029_IRQ_FLAGS_V1IF BIT(2)
#define RV3029_IRQ_FLAGS_V2IF BIT(3)
#define RV3029_IRQ_FLAGS_SRF BIT(4)
#define RV3029_STATUS 0x03
#define RV3029_STATUS_VLOW1 BIT(2)
#define RV3029_STATUS_VLOW2 BIT(3)
#define RV3029_STATUS_SR BIT(4)
#define RV3029_STATUS_PON BIT(5)
#define RV3029_STATUS_EEBUSY BIT(7)
#define RV3029_RST_CTRL 0x04
#define RV3029_RST_CTRL_SYSR BIT(4)
#define RV3029_CONTROL_SECTION_LEN 0x05
/* watch section */
#define RV3029_W_SEC 0x08
#define RV3029_W_MINUTES 0x09
#define RV3029_W_HOURS 0x0A
#define RV3029_REG_HR_12_24 BIT(6) /* 24h/12h mode */
#define RV3029_REG_HR_PM BIT(5) /* PM/AM bit in 12h mode */
#define RV3029_W_DATE 0x0B
#define RV3029_W_DAYS 0x0C
#define RV3029_W_MONTHS 0x0D
#define RV3029_W_YEARS 0x0E
#define RV3029_WATCH_SECTION_LEN 0x07
/* alarm section */
#define RV3029_A_SC 0x10
#define RV3029_A_MN 0x11
#define RV3029_A_HR 0x12
#define RV3029_A_DT 0x13
#define RV3029_A_DW 0x14
#define RV3029_A_MO 0x15
#define RV3029_A_YR 0x16
#define RV3029_ALARM_SECTION_LEN 0x07
/* timer section */
#define RV3029_TIMER_LOW 0x18
#define RV3029_TIMER_HIGH 0x19
/* temperature section */
#define RV3029_TEMP_PAGE 0x20
/* eeprom data section */
#define RV3029_E2P_EEDATA1 0x28
#define RV3029_E2P_EEDATA2 0x29
#define RV3029_E2PDATA_SECTION_LEN 0x02
/* eeprom control section */
#define RV3029_CONTROL_E2P_EECTRL 0x30
#define RV3029_EECTRL_THP BIT(0) /* temp scan interval */
#define RV3029_EECTRL_THE BIT(1) /* thermometer enable */
#define RV3029_EECTRL_FD0 BIT(2) /* CLKOUT */
#define RV3029_EECTRL_FD1 BIT(3) /* CLKOUT */
#define RV3029_TRICKLE_1K BIT(4) /* 1.5K resistance */
#define RV3029_TRICKLE_5K BIT(5) /* 5K resistance */
#define RV3029_TRICKLE_20K BIT(6) /* 20K resistance */
#define RV3029_TRICKLE_80K BIT(7) /* 80K resistance */
#define RV3029_TRICKLE_MASK (RV3029_TRICKLE_1K |\
RV3029_TRICKLE_5K |\
RV3029_TRICKLE_20K |\
RV3029_TRICKLE_80K)
#define RV3029_TRICKLE_SHIFT 4
#define RV3029_CONTROL_E2P_XOFFS 0x31 /* XTAL offset */
#define RV3029_CONTROL_E2P_XOFFS_SIGN BIT(7) /* Sign: 1->pos, 0->neg */
#define RV3029_CONTROL_E2P_QCOEF 0x32 /* XTAL temp drift coef */
#define RV3029_CONTROL_E2P_TURNOVER 0x33 /* XTAL turnover temp (in *C) */
#define RV3029_CONTROL_E2P_TOV_MASK 0x3F /* XTAL turnover temp mask */
/* user ram section */
#define RV3029_USR1_RAM_PAGE 0x38
#define RV3029_USR1_SECTION_LEN 0x04
#define RV3029_USR2_RAM_PAGE 0x3C
#define RV3029_USR2_SECTION_LEN 0x04
static int
rv3029_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf,
unsigned len)
{
int ret;
if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
(reg + len > RV3029_USR1_RAM_PAGE + 8))
return -EINVAL;
ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
if (ret < 0)
return ret;
if (ret < len)
return -EIO;
return 0;
}
static int
rv3029_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[],
unsigned len)
{
if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
(reg + len > RV3029_USR1_RAM_PAGE + 8))
return -EINVAL;
return i2c_smbus_write_i2c_block_data(client, reg, len, buf);
}
static int
rv3029_i2c_update_bits(struct i2c_client *client, u8 reg, u8 mask, u8 set)
{
u8 buf;
int ret;
ret = rv3029_i2c_read_regs(client, reg, &buf, 1);
if (ret < 0)
return ret;
buf &= ~mask;
buf |= set & mask;
ret = rv3029_i2c_write_regs(client, reg, &buf, 1);
if (ret < 0)
return ret;
return 0;
}
static int
rv3029_i2c_get_sr(struct i2c_client *client, u8 *buf)
{
int ret = rv3029_i2c_read_regs(client, RV3029_STATUS, buf, 1);
if (ret < 0)
return -EIO;
dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
return 0;
}
static int
rv3029_i2c_set_sr(struct i2c_client *client, u8 val)
{
u8 buf[1];
int sr;
buf[0] = val;
sr = rv3029_i2c_write_regs(client, RV3029_STATUS, buf, 1);
dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
if (sr < 0)
return -EIO;
return 0;
}
static int rv3029_eeprom_busywait(struct i2c_client *client)
{
int i, ret;
u8 sr;
for (i = 100; i > 0; i--) {
ret = rv3029_i2c_get_sr(client, &sr);
if (ret < 0)
break;
if (!(sr & RV3029_STATUS_EEBUSY))
break;
usleep_range(1000, 10000);
}
if (i <= 0) {
dev_err(&client->dev, "EEPROM busy wait timeout.\n");
return -ETIMEDOUT;
}
return ret;
}
static int rv3029_eeprom_exit(struct i2c_client *client)
{
/* Re-enable eeprom refresh */
return rv3029_i2c_update_bits(client, RV3029_ONOFF_CTRL,
RV3029_ONOFF_CTRL_EERE,
RV3029_ONOFF_CTRL_EERE);
}
static int rv3029_eeprom_enter(struct i2c_client *client)
{
int ret;
u8 sr;
/* Check whether we are in the allowed voltage range. */
ret = rv3029_i2c_get_sr(client, &sr);
if (ret < 0)
return ret;
if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
/* We clear the bits and retry once just in case
* we had a brown out in early startup.
*/
sr &= ~RV3029_STATUS_VLOW1;
sr &= ~RV3029_STATUS_VLOW2;
ret = rv3029_i2c_set_sr(client, sr);
if (ret < 0)
return ret;
usleep_range(1000, 10000);
ret = rv3029_i2c_get_sr(client,
|