mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 16:56:40 +07:00
feb141d11a
devm_rtc_device_register() is device managed and makes cleanup paths simpler. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
265 lines
6.7 KiB
C
265 lines
6.7 KiB
C
/*
|
|
* rtc class driver for the Maxim MAX6900 chip
|
|
*
|
|
* Author: Dale Farnsworth <dale@farnsworth.org>
|
|
*
|
|
* based on previously existing rtc class drivers
|
|
*
|
|
* 2007 (c) MontaVista, Software, Inc. This file is licensed under
|
|
* the terms of the GNU General Public License version 2. This program
|
|
* is licensed "as is" without any warranty of any kind, whether express
|
|
* or implied.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/bcd.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/delay.h>
|
|
|
|
#define DRV_VERSION "0.2"
|
|
|
|
/*
|
|
* register indices
|
|
*/
|
|
#define MAX6900_REG_SC 0 /* seconds 00-59 */
|
|
#define MAX6900_REG_MN 1 /* minutes 00-59 */
|
|
#define MAX6900_REG_HR 2 /* hours 00-23 */
|
|
#define MAX6900_REG_DT 3 /* day of month 00-31 */
|
|
#define MAX6900_REG_MO 4 /* month 01-12 */
|
|
#define MAX6900_REG_DW 5 /* day of week 1-7 */
|
|
#define MAX6900_REG_YR 6 /* year 00-99 */
|
|
#define MAX6900_REG_CT 7 /* control */
|
|
/* register 8 is undocumented */
|
|
#define MAX6900_REG_CENTURY 9 /* century */
|
|
#define MAX6900_REG_LEN 10
|
|
|
|
#define MAX6900_BURST_LEN 8 /* can burst r/w first 8 regs */
|
|
|
|
#define MAX6900_REG_CT_WP (1 << 7) /* Write Protect */
|
|
|
|
/*
|
|
* register read/write commands
|
|
*/
|
|
#define MAX6900_REG_CONTROL_WRITE 0x8e
|
|
#define MAX6900_REG_CENTURY_WRITE 0x92
|
|
#define MAX6900_REG_CENTURY_READ 0x93
|
|
#define MAX6900_REG_RESERVED_READ 0x96
|
|
#define MAX6900_REG_BURST_WRITE 0xbe
|
|
#define MAX6900_REG_BURST_READ 0xbf
|
|
|
|
#define MAX6900_IDLE_TIME_AFTER_WRITE 3 /* specification says 2.5 mS */
|
|
|
|
static struct i2c_driver max6900_driver;
|
|
|
|
static int max6900_i2c_read_regs(struct i2c_client *client, u8 *buf)
|
|
{
|
|
u8 reg_burst_read[1] = { MAX6900_REG_BURST_READ };
|
|
u8 reg_century_read[1] = { MAX6900_REG_CENTURY_READ };
|
|
struct i2c_msg msgs[4] = {
|
|
{
|
|
.addr = client->addr,
|
|
.flags = 0, /* write */
|
|
.len = sizeof(reg_burst_read),
|
|
.buf = reg_burst_read}
|
|
,
|
|
{
|
|
.addr = client->addr,
|
|
.flags = I2C_M_RD,
|
|
.len = MAX6900_BURST_LEN,
|
|
.buf = buf}
|
|
,
|
|
{
|
|
.addr = client->addr,
|
|
.flags = 0, /* write */
|
|
.len = sizeof(reg_century_read),
|
|
.buf = reg_century_read}
|
|
,
|
|
{
|
|
.addr = client->addr,
|
|
.flags = I2C_M_RD,
|
|
.len = sizeof(buf[MAX6900_REG_CENTURY]),
|
|
.buf = &buf[MAX6900_REG_CENTURY]
|
|
}
|
|
};
|
|
int rc;
|
|
|
|
rc = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
|
|
if (rc != ARRAY_SIZE(msgs)) {
|
|
dev_err(&client->dev, "%s: register read failed\n", __func__);
|
|
return -EIO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int max6900_i2c_write_regs(struct i2c_client *client, u8 const *buf)
|
|
{
|
|
u8 i2c_century_buf[1 + 1] = { MAX6900_REG_CENTURY_WRITE };
|
|
struct i2c_msg century_msgs[1] = {
|
|
{
|
|
.addr = client->addr,
|
|
.flags = 0, /* write */
|
|
.len = sizeof(i2c_century_buf),
|
|
.buf = i2c_century_buf}
|
|
};
|
|
u8 i2c_burst_buf[MAX6900_BURST_LEN + 1] = { MAX6900_REG_BURST_WRITE };
|
|
struct i2c_msg burst_msgs[1] = {
|
|
{
|
|
.addr = client->addr,
|
|
.flags = 0, /* write */
|
|
.len = sizeof(i2c_burst_buf),
|
|
.buf = i2c_burst_buf}
|
|
};
|
|
int rc;
|
|
|
|
/*
|
|
* We have to make separate calls to i2c_transfer because of
|
|
* the need to delay after each write to the chip. Also,
|
|
* we write the century byte first, since we set the write-protect
|
|
* bit as part of the burst write.
|
|
*/
|
|
i2c_century_buf[1] = buf[MAX6900_REG_CENTURY];
|
|
|
|
rc = i2c_transfer(client->adapter, century_msgs,
|
|
ARRAY_SIZE(century_msgs));
|
|
if (rc != ARRAY_SIZE(century_msgs))
|
|
goto write_failed;
|
|
|
|
msleep(MAX6900_IDLE_TIME_AFTER_WRITE);
|
|
|
|
memcpy(&i2c_burst_buf[1], buf, MAX6900_BURST_LEN);
|
|
|
|
rc = i2c_transfer(client->adapter, burst_msgs, ARRAY_SIZE(burst_msgs));
|
|
if (rc != ARRAY_SIZE(burst_msgs))
|
|
goto write_failed;
|
|
msleep(MAX6900_IDLE_TIME_AFTER_WRITE);
|
|
|
|
return 0;
|
|
|
|
write_failed:
|
|
dev_err(&client->dev, "%s: register write failed\n", __func__);
|
|
return -EIO;
|
|
}
|
|
|
|
static int max6900_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
|
|
{
|
|
int rc;
|
|
u8 regs[MAX6900_REG_LEN];
|
|
|
|
rc = max6900_i2c_read_regs(client, regs);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
tm->tm_sec = bcd2bin(regs[MAX6900_REG_SC]);
|
|
tm->tm_min = bcd2bin(regs[MAX6900_REG_MN]);
|
|
tm->tm_hour = bcd2bin(regs[MAX6900_REG_HR] & 0x3f);
|
|
tm->tm_mday = bcd2bin(regs[MAX6900_REG_DT]);
|
|
tm->tm_mon = bcd2bin(regs[MAX6900_REG_MO]) - 1;
|
|
tm->tm_year = bcd2bin(regs[MAX6900_REG_YR]) +
|
|
bcd2bin(regs[MAX6900_REG_CENTURY]) * 100 - 1900;
|
|
tm->tm_wday = bcd2bin(regs[MAX6900_REG_DW]);
|
|
|
|
return rtc_valid_tm(tm);
|
|
}
|
|
|
|
static int max6900_i2c_clear_write_protect(struct i2c_client *client)
|
|
{
|
|
int rc;
|
|
rc = i2c_smbus_write_byte_data(client, MAX6900_REG_CONTROL_WRITE, 0);
|
|
if (rc < 0) {
|
|
dev_err(&client->dev, "%s: control register write failed\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
max6900_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
|
|
{
|
|
u8 regs[MAX6900_REG_LEN];
|
|
int rc;
|
|
|
|
rc = max6900_i2c_clear_write_protect(client);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
regs[MAX6900_REG_SC] = bin2bcd(tm->tm_sec);
|
|
regs[MAX6900_REG_MN] = bin2bcd(tm->tm_min);
|
|
regs[MAX6900_REG_HR] = bin2bcd(tm->tm_hour);
|
|
regs[MAX6900_REG_DT] = bin2bcd(tm->tm_mday);
|
|
regs[MAX6900_REG_MO] = bin2bcd(tm->tm_mon + 1);
|
|
regs[MAX6900_REG_DW] = bin2bcd(tm->tm_wday);
|
|
regs[MAX6900_REG_YR] = bin2bcd(tm->tm_year % 100);
|
|
regs[MAX6900_REG_CENTURY] = bin2bcd((tm->tm_year + 1900) / 100);
|
|
/* set write protect */
|
|
regs[MAX6900_REG_CT] = MAX6900_REG_CT_WP;
|
|
|
|
rc = max6900_i2c_write_regs(client, regs);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int max6900_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
return max6900_i2c_read_time(to_i2c_client(dev), tm);
|
|
}
|
|
|
|
static int max6900_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
return max6900_i2c_set_time(to_i2c_client(dev), tm);
|
|
}
|
|
|
|
static int max6900_remove(struct i2c_client *client)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops max6900_rtc_ops = {
|
|
.read_time = max6900_rtc_read_time,
|
|
.set_time = max6900_rtc_set_time,
|
|
};
|
|
|
|
static int
|
|
max6900_probe(struct i2c_client *client, const struct i2c_device_id *id)
|
|
{
|
|
struct rtc_device *rtc;
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
|
return -ENODEV;
|
|
|
|
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
|
|
|
|
rtc = devm_rtc_device_register(&client->dev, max6900_driver.driver.name,
|
|
&max6900_rtc_ops, THIS_MODULE);
|
|
if (IS_ERR(rtc))
|
|
return PTR_ERR(rtc);
|
|
|
|
i2c_set_clientdata(client, rtc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct i2c_device_id max6900_id[] = {
|
|
{ "max6900", 0 },
|
|
{ }
|
|
};
|
|
|
|
static struct i2c_driver max6900_driver = {
|
|
.driver = {
|
|
.name = "rtc-max6900",
|
|
},
|
|
.probe = max6900_probe,
|
|
.remove = max6900_remove,
|
|
.id_table = max6900_id,
|
|
};
|
|
|
|
module_i2c_driver(max6900_driver);
|
|
|
|
MODULE_DESCRIPTION("Maxim MAX6900 RTC driver");
|
|
MODULE_AUTHOR("Dale Farnsworth <dale@farnsworth.org>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(DRV_VERSION);
|