307 строки
8.9 KiB
C
307 строки
8.9 KiB
C
/*
|
|
* rtc-isl12057 - Driver for Intersil ISL12057 I2C Real Time Clock
|
|
*
|
|
* Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
|
|
*
|
|
* This work is largely based on Intersil ISL1208 driver developed by
|
|
* Hebert Valerio Riedel <hvr@gnu.org>.
|
|
*
|
|
* Detailed datasheet on which this development is based is available here:
|
|
*
|
|
* http://natisbad.org/NAS2/refs/ISL12057.pdf
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/bcd.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/regmap.h>
|
|
|
|
#define DRV_NAME "rtc-isl12057"
|
|
|
|
/* RTC section */
|
|
#define ISL12057_REG_RTC_SC 0x00 /* Seconds */
|
|
#define ISL12057_REG_RTC_MN 0x01 /* Minutes */
|
|
#define ISL12057_REG_RTC_HR 0x02 /* Hours */
|
|
#define ISL12057_REG_RTC_HR_PM BIT(5) /* AM/PM bit in 12h format */
|
|
#define ISL12057_REG_RTC_HR_MIL BIT(6) /* 24h/12h format */
|
|
#define ISL12057_REG_RTC_DW 0x03 /* Day of the Week */
|
|
#define ISL12057_REG_RTC_DT 0x04 /* Date */
|
|
#define ISL12057_REG_RTC_MO 0x05 /* Month */
|
|
#define ISL12057_REG_RTC_YR 0x06 /* Year */
|
|
#define ISL12057_RTC_SEC_LEN 7
|
|
|
|
/* Alarm 1 section */
|
|
#define ISL12057_REG_A1_SC 0x07 /* Alarm 1 Seconds */
|
|
#define ISL12057_REG_A1_MN 0x08 /* Alarm 1 Minutes */
|
|
#define ISL12057_REG_A1_HR 0x09 /* Alarm 1 Hours */
|
|
#define ISL12057_REG_A1_HR_PM BIT(5) /* AM/PM bit in 12h format */
|
|
#define ISL12057_REG_A1_HR_MIL BIT(6) /* 24h/12h format */
|
|
#define ISL12057_REG_A1_DWDT 0x0A /* Alarm 1 Date / Day of the week */
|
|
#define ISL12057_REG_A1_DWDT_B BIT(6) /* DW / DT selection bit */
|
|
#define ISL12057_A1_SEC_LEN 4
|
|
|
|
/* Alarm 2 section */
|
|
#define ISL12057_REG_A2_MN 0x0B /* Alarm 2 Minutes */
|
|
#define ISL12057_REG_A2_HR 0x0C /* Alarm 2 Hours */
|
|
#define ISL12057_REG_A2_DWDT 0x0D /* Alarm 2 Date / Day of the week */
|
|
#define ISL12057_A2_SEC_LEN 3
|
|
|
|
/* Control/Status registers */
|
|
#define ISL12057_REG_INT 0x0E
|
|
#define ISL12057_REG_INT_A1IE BIT(0) /* Alarm 1 interrupt enable bit */
|
|
#define ISL12057_REG_INT_A2IE BIT(1) /* Alarm 2 interrupt enable bit */
|
|
#define ISL12057_REG_INT_INTCN BIT(2) /* Interrupt control enable bit */
|
|
#define ISL12057_REG_INT_RS1 BIT(3) /* Freq out control bit 1 */
|
|
#define ISL12057_REG_INT_RS2 BIT(4) /* Freq out control bit 2 */
|
|
#define ISL12057_REG_INT_EOSC BIT(7) /* Oscillator enable bit */
|
|
|
|
#define ISL12057_REG_SR 0x0F
|
|
#define ISL12057_REG_SR_A1F BIT(0) /* Alarm 1 interrupt bit */
|
|
#define ISL12057_REG_SR_A2F BIT(1) /* Alarm 2 interrupt bit */
|
|
#define ISL12057_REG_SR_OSF BIT(7) /* Oscillator failure bit */
|
|
|
|
/* Register memory map length */
|
|
#define ISL12057_MEM_MAP_LEN 0x10
|
|
|
|
struct isl12057_rtc_data {
|
|
struct regmap *regmap;
|
|
struct mutex lock;
|
|
};
|
|
|
|
static void isl12057_rtc_regs_to_tm(struct rtc_time *tm, u8 *regs)
|
|
{
|
|
tm->tm_sec = bcd2bin(regs[ISL12057_REG_RTC_SC]);
|
|
tm->tm_min = bcd2bin(regs[ISL12057_REG_RTC_MN]);
|
|
|
|
if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_MIL) { /* AM/PM */
|
|
tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x0f);
|
|
if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_PM)
|
|
tm->tm_hour += 12;
|
|
} else { /* 24 hour mode */
|
|
tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x3f);
|
|
}
|
|
|
|
tm->tm_mday = bcd2bin(regs[ISL12057_REG_RTC_DT]);
|
|
tm->tm_wday = bcd2bin(regs[ISL12057_REG_RTC_DW]) - 1; /* starts at 1 */
|
|
tm->tm_mon = bcd2bin(regs[ISL12057_REG_RTC_MO]) - 1; /* starts at 1 */
|
|
tm->tm_year = bcd2bin(regs[ISL12057_REG_RTC_YR]) + 100;
|
|
}
|
|
|
|
static int isl12057_rtc_tm_to_regs(u8 *regs, struct rtc_time *tm)
|
|
{
|
|
/*
|
|
* The clock has an 8 bit wide bcd-coded register for the year.
|
|
* tm_year is an offset from 1900 and we are interested in the
|
|
* 2000-2099 range, so any value less than 100 is invalid.
|
|
*/
|
|
if (tm->tm_year < 100)
|
|
return -EINVAL;
|
|
|
|
regs[ISL12057_REG_RTC_SC] = bin2bcd(tm->tm_sec);
|
|
regs[ISL12057_REG_RTC_MN] = bin2bcd(tm->tm_min);
|
|
regs[ISL12057_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */
|
|
regs[ISL12057_REG_RTC_DT] = bin2bcd(tm->tm_mday);
|
|
regs[ISL12057_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1);
|
|
regs[ISL12057_REG_RTC_YR] = bin2bcd(tm->tm_year - 100);
|
|
regs[ISL12057_REG_RTC_DW] = bin2bcd(tm->tm_wday + 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Try and match register bits w/ fixed null values to see whether we
|
|
* are dealing with an ISL12057. Note: this function is called early
|
|
* during init and hence does need mutex protection.
|
|
*/
|
|
static int isl12057_i2c_validate_chip(struct regmap *regmap)
|
|
{
|
|
u8 regs[ISL12057_MEM_MAP_LEN];
|
|
static const u8 mask[ISL12057_MEM_MAP_LEN] = { 0x80, 0x80, 0x80, 0xf8,
|
|
0xc0, 0x60, 0x00, 0x00,
|
|
0x00, 0x00, 0x00, 0x00,
|
|
0x00, 0x00, 0x60, 0x7c };
|
|
int ret, i;
|
|
|
|
ret = regmap_bulk_read(regmap, 0, regs, ISL12057_MEM_MAP_LEN);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (i = 0; i < ISL12057_MEM_MAP_LEN; ++i) {
|
|
if (regs[i] & mask[i]) /* check if bits are cleared */
|
|
return -ENODEV;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct isl12057_rtc_data *data = dev_get_drvdata(dev);
|
|
u8 regs[ISL12057_RTC_SEC_LEN];
|
|
int ret;
|
|
|
|
mutex_lock(&data->lock);
|
|
ret = regmap_bulk_read(data->regmap, ISL12057_REG_RTC_SC, regs,
|
|
ISL12057_RTC_SEC_LEN);
|
|
mutex_unlock(&data->lock);
|
|
|
|
if (ret) {
|
|
dev_err(dev, "%s: RTC read failed\n", __func__);
|
|
return ret;
|
|
}
|
|
|
|
isl12057_rtc_regs_to_tm(tm, regs);
|
|
|
|
return rtc_valid_tm(tm);
|
|
}
|
|
|
|
static int isl12057_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct isl12057_rtc_data *data = dev_get_drvdata(dev);
|
|
u8 regs[ISL12057_RTC_SEC_LEN];
|
|
int ret;
|
|
|
|
ret = isl12057_rtc_tm_to_regs(regs, tm);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&data->lock);
|
|
ret = regmap_bulk_write(data->regmap, ISL12057_REG_RTC_SC, regs,
|
|
ISL12057_RTC_SEC_LEN);
|
|
mutex_unlock(&data->lock);
|
|
|
|
if (ret)
|
|
dev_err(dev, "%s: RTC write failed\n", __func__);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Check current RTC status and enable/disable what needs to be. Return 0 if
|
|
* everything went ok and a negative value upon error. Note: this function
|
|
* is called early during init and hence does need mutex protection.
|
|
*/
|
|
static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap)
|
|
{
|
|
int ret;
|
|
|
|
/* Enable oscillator if not already running */
|
|
ret = regmap_update_bits(regmap, ISL12057_REG_INT,
|
|
ISL12057_REG_INT_EOSC, 0);
|
|
if (ret < 0) {
|
|
dev_err(dev, "Unable to enable oscillator\n");
|
|
return ret;
|
|
}
|
|
|
|
/* Clear oscillator failure bit if needed */
|
|
ret = regmap_update_bits(regmap, ISL12057_REG_SR,
|
|
ISL12057_REG_SR_OSF, 0);
|
|
if (ret < 0) {
|
|
dev_err(dev, "Unable to clear oscillator failure bit\n");
|
|
return ret;
|
|
}
|
|
|
|
/* Clear alarm bit if needed */
|
|
ret = regmap_update_bits(regmap, ISL12057_REG_SR,
|
|
ISL12057_REG_SR_A1F, 0);
|
|
if (ret < 0) {
|
|
dev_err(dev, "Unable to clear alarm bit\n");
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops rtc_ops = {
|
|
.read_time = isl12057_rtc_read_time,
|
|
.set_time = isl12057_rtc_set_time,
|
|
};
|
|
|
|
static struct regmap_config isl12057_rtc_regmap_config = {
|
|
.reg_bits = 8,
|
|
.val_bits = 8,
|
|
};
|
|
|
|
static int isl12057_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
struct device *dev = &client->dev;
|
|
struct isl12057_rtc_data *data;
|
|
struct rtc_device *rtc;
|
|
struct regmap *regmap;
|
|
int ret;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
|
|
I2C_FUNC_SMBUS_BYTE_DATA |
|
|
I2C_FUNC_SMBUS_I2C_BLOCK))
|
|
return -ENODEV;
|
|
|
|
regmap = devm_regmap_init_i2c(client, &isl12057_rtc_regmap_config);
|
|
if (IS_ERR(regmap)) {
|
|
ret = PTR_ERR(regmap);
|
|
dev_err(dev, "regmap allocation failed: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = isl12057_i2c_validate_chip(regmap);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = isl12057_check_rtc_status(dev, regmap);
|
|
if (ret)
|
|
return ret;
|
|
|
|
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
mutex_init(&data->lock);
|
|
data->regmap = regmap;
|
|
dev_set_drvdata(dev, data);
|
|
|
|
rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops, THIS_MODULE);
|
|
return PTR_ERR_OR_ZERO(rtc);
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id isl12057_dt_match[] = {
|
|
{ .compatible = "isl,isl12057" },
|
|
{ },
|
|
};
|
|
#endif
|
|
|
|
static const struct i2c_device_id isl12057_id[] = {
|
|
{ "isl12057", 0 },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, isl12057_id);
|
|
|
|
static struct i2c_driver isl12057_driver = {
|
|
.driver = {
|
|
.name = DRV_NAME,
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = of_match_ptr(isl12057_dt_match),
|
|
},
|
|
.probe = isl12057_probe,
|
|
.id_table = isl12057_id,
|
|
};
|
|
module_i2c_driver(isl12057_driver);
|
|
|
|
MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
|
|
MODULE_DESCRIPTION("Intersil ISL12057 RTC driver");
|
|
MODULE_LICENSE("GPL");
|