renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-11-28 12:35:22 +08:00
Code
ca03b7a2c0
linux-next/drivers/rtc/rtc-isl12022.c
Rasmus Villemoes ca03b7a2c0 rtc: isl12022: specify range_min and range_max 
The isl12022 can (only) keep track of times in the range
2000-2099. The data sheet says

  The calendar registers track date, month, year, and day of the week
  and are accurate through 2099, with automatic leap year correction.

The lower bound of 2000 is obtained by simply observing that its YR
register only counts from 00 through 99.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20220921114624.3250848-3-linux@rasmusvillemoes.dk
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-10-13 00:17:21 +02:00

291 lines
6.9 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-only
/*
* An I2C driver for the Intersil ISL 12022
*
* Author: Roman Fietze <roman.fietze@telemotive.de>
*
* Based on the Philips PCF8563 RTC
* by Alessandro Zummo <a.zummo@towertech.it>.
*/
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_device.h>
/* ISL register offsets */
#define ISL12022_REG_SC 0x00
#define ISL12022_REG_MN 0x01
#define ISL12022_REG_HR 0x02
#define ISL12022_REG_DT 0x03
#define ISL12022_REG_MO 0x04
#define ISL12022_REG_YR 0x05
#define ISL12022_REG_DW 0x06
#define ISL12022_REG_SR 0x07
#define ISL12022_REG_INT 0x08
/* ISL register bits */
#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */
#define ISL12022_SR_LBAT85 (1 << 2)
#define ISL12022_SR_LBAT75 (1 << 1)
#define ISL12022_INT_WRTC (1 << 6)
static struct i2c_driver isl12022_driver;
struct isl12022 {
struct rtc_device *rtc;
bool write_enabled; /* true if write enable is set */
};
static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
uint8_t *data, size_t n)
{
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = data
}, /* setup read ptr */
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = n,
.buf = data
}
};
int ret;
data[0] = reg;
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (ret != ARRAY_SIZE(msgs)) {
dev_err(&client->dev, "%s: read error, ret=%d\n",
__func__, ret);
return -EIO;
}
return 0;
}
static int isl12022_write_reg(struct i2c_client *client,
uint8_t reg, uint8_t val)
{
uint8_t data[2] = { reg, val };
int err;
err = i2c_master_send(client, data, sizeof(data));
if (err != sizeof(data)) {
dev_err(&client->dev,
"%s: err=%d addr=%02x, data=%02x\n",
__func__, err, data[0], data[1]);
return -EIO;
}
return 0;
}
/*
* In the routines that deal directly with the isl12022 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/
static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
uint8_t buf[ISL12022_REG_INT + 1];
int ret;
ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
if (ret)
return ret;
if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
dev_warn(&client->dev,
"voltage dropped below %u%%, "
"date and time is not reliable.\n",
buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
}
dev_dbg(&client->dev,
"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
"sr=%02x, int=%02x",
__func__,
buf[ISL12022_REG_SC],
buf[ISL12022_REG_MN],
buf[ISL12022_REG_HR],
buf[ISL12022_REG_DT],
buf[ISL12022_REG_MO],
buf[ISL12022_REG_YR],
buf[ISL12022_REG_DW],
buf[ISL12022_REG_SR],
buf[ISL12022_REG_INT]);
tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;
dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
return 0;
}
static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
struct isl12022 *isl12022 = i2c_get_clientdata(client);
size_t i;
int ret;
uint8_t buf[ISL12022_REG_DW + 1];
dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
if (!isl12022->write_enabled) {
ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
if (ret)
return ret;
/* Check if WRTC (write rtc enable) is set factory default is
* 0 (not set) */
if (!(buf[0] & ISL12022_INT_WRTC)) {
dev_info(&client->dev,
"init write enable and 24 hour format\n");
/* Set the write enable bit. */
ret = isl12022_write_reg(client,
ISL12022_REG_INT,
buf[0] | ISL12022_INT_WRTC);
if (ret)
return ret;
/* Write to any RTC register to start RTC, we use the
* HR register, setting the MIL bit to use the 24 hour
* format. */
ret = isl12022_read_regs(client, ISL12022_REG_HR,
buf, 1);
if (ret)
return ret;
ret = isl12022_write_reg(client,
ISL12022_REG_HR,
buf[0] | ISL12022_HR_MIL);
if (ret)
return ret;
}
isl12022->write_enabled = true;
}
/* hours, minutes and seconds */
buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;
buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);
/* month, 1 - 12 */
buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);
/* year and century */
buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);
buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;
/* write register's data */
for (i = 0; i < ARRAY_SIZE(buf); i++) {
ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
buf[ISL12022_REG_SC + i]);
if (ret)
return -EIO;
}
return 0;
}
static const struct rtc_class_ops isl12022_rtc_ops = {
.read_time = isl12022_rtc_read_time,
.set_time = isl12022_rtc_set_time,
};
static int isl12022_probe(struct i2c_client *client)
{
struct isl12022 *isl12022;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
GFP_KERNEL);
if (!isl12022)
return -ENOMEM;
i2c_set_clientdata(client, isl12022);
isl12022->rtc = devm_rtc_allocate_device(&client->dev);
if (IS_ERR(isl12022->rtc))
return PTR_ERR(isl12022->rtc);
isl12022->rtc->ops = &isl12022_rtc_ops;
isl12022->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
isl12022->rtc->range_max = RTC_TIMESTAMP_END_2099;
return devm_rtc_register_device(isl12022->rtc);
}
#ifdef CONFIG_OF
static const struct of_device_id isl12022_dt_match[] = {
{ .compatible = "isl,isl12022" }, /* for backward compat., don't use */
{ .compatible = "isil,isl12022" },
{ },
};
MODULE_DEVICE_TABLE(of, isl12022_dt_match);
#endif
static const struct i2c_device_id isl12022_id[] = {
{ "isl12022", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, isl12022_id);
static struct i2c_driver isl12022_driver = {
.driver = {
.name = "rtc-isl12022",
#ifdef CONFIG_OF
.of_match_table = of_match_ptr(isl12022_dt_match),
#endif
},
.probe_new = isl12022_probe,
.id_table = isl12022_id,
};
module_i2c_driver(isl12022_driver);
MODULE_AUTHOR("roman.fietze@telemotive.de");
MODULE_DESCRIPTION("ISL 12022 RTC driver");
MODULE_LICENSE("GPL");
View Git Blame Copy Permalink