500 lines
12 KiB
C
500 lines
12 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
/*
|
||
|
* Copyright (C) 2012 Avionic Design GmbH
|
||
|
*/
|
||
|
|
||
|
#include <linux/bcd.h>
|
||
|
#include <linux/bitfield.h>
|
||
|
#include <linux/i2c.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/regmap.h>
|
||
|
#include <linux/rtc.h>
|
||
|
#include <linux/of.h>
|
||
|
#include <linux/pm_wakeirq.h>
|
||
|
|
||
|
#define PCF8523_REG_CONTROL1 0x00
|
||
|
#define PCF8523_CONTROL1_CAP_SEL BIT(7)
|
||
|
#define PCF8523_CONTROL1_STOP BIT(5)
|
||
|
#define PCF8523_CONTROL1_AIE BIT(1)
|
||
|
|
||
|
#define PCF8523_REG_CONTROL2 0x01
|
||
|
#define PCF8523_CONTROL2_AF BIT(3)
|
||
|
|
||
|
#define PCF8523_REG_CONTROL3 0x02
|
||
|
#define PCF8523_CONTROL3_PM GENMASK(7,5)
|
||
|
#define PCF8523_PM_STANDBY 0x7
|
||
|
#define PCF8523_CONTROL3_BLF BIT(2) /* battery low bit, read-only */
|
||
|
#define PCF8523_CONTROL3_BSF BIT(3)
|
||
|
|
||
|
#define PCF8523_REG_SECONDS 0x03
|
||
|
#define PCF8523_SECONDS_OS BIT(7)
|
||
|
|
||
|
#define PCF8523_REG_MINUTES 0x04
|
||
|
#define PCF8523_REG_HOURS 0x05
|
||
|
#define PCF8523_REG_DAYS 0x06
|
||
|
#define PCF8523_REG_WEEKDAYS 0x07
|
||
|
#define PCF8523_REG_MONTHS 0x08
|
||
|
#define PCF8523_REG_YEARS 0x09
|
||
|
|
||
|
#define PCF8523_REG_MINUTE_ALARM 0x0a
|
||
|
#define PCF8523_REG_HOUR_ALARM 0x0b
|
||
|
#define PCF8523_REG_DAY_ALARM 0x0c
|
||
|
#define PCF8523_REG_WEEKDAY_ALARM 0x0d
|
||
|
#define ALARM_DIS BIT(7)
|
||
|
|
||
|
#define PCF8523_REG_OFFSET 0x0e
|
||
|
#define PCF8523_OFFSET_MODE BIT(7)
|
||
|
|
||
|
#define PCF8523_TMR_CLKOUT_CTRL 0x0f
|
||
|
|
||
|
struct pcf8523 {
|
||
|
struct rtc_device *rtc;
|
||
|
struct regmap *regmap;
|
||
|
};
|
||
|
|
||
|
static int pcf8523_load_capacitance(struct pcf8523 *pcf8523, struct device_node *node)
|
||
|
{
|
||
|
u32 load, value = 0;
|
||
|
|
||
|
load = 12500;
|
||
|
of_property_read_u32(node, "quartz-load-femtofarads", &load);
|
||
|
|
||
|
switch (load) {
|
||
|
default:
|
||
|
dev_warn(&pcf8523->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 12500",
|
||
|
load);
|
||
|
fallthrough;
|
||
|
case 12500:
|
||
|
value |= PCF8523_CONTROL1_CAP_SEL;
|
||
|
break;
|
||
|
case 7000:
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
|
||
|
PCF8523_CONTROL1_CAP_SEL, value);
|
||
|
}
|
||
|
|
||
|
static irqreturn_t pcf8523_irq(int irq, void *dev_id)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_id;
|
||
|
u32 value;
|
||
|
int err;
|
||
|
|
||
|
err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
|
||
|
if (err < 0)
|
||
|
return IRQ_HANDLED;
|
||
|
|
||
|
if (value & PCF8523_CONTROL2_AF) {
|
||
|
value &= ~PCF8523_CONTROL2_AF;
|
||
|
regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, value);
|
||
|
rtc_update_irq(pcf8523->rtc, 1, RTC_IRQF | RTC_AF);
|
||
|
|
||
|
return IRQ_HANDLED;
|
||
|
}
|
||
|
|
||
|
return IRQ_NONE;
|
||
|
}
|
||
|
|
||
|
static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
u8 regs[10];
|
||
|
int err;
|
||
|
|
||
|
err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_CONTROL1, regs,
|
||
|
sizeof(regs));
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
if ((regs[0] & PCF8523_CONTROL1_STOP) || (regs[3] & PCF8523_SECONDS_OS))
|
||
|
return -EINVAL;
|
||
|
|
||
|
tm->tm_sec = bcd2bin(regs[3] & 0x7f);
|
||
|
tm->tm_min = bcd2bin(regs[4] & 0x7f);
|
||
|
tm->tm_hour = bcd2bin(regs[5] & 0x3f);
|
||
|
tm->tm_mday = bcd2bin(regs[6] & 0x3f);
|
||
|
tm->tm_wday = regs[7] & 0x7;
|
||
|
tm->tm_mon = bcd2bin(regs[8] & 0x1f) - 1;
|
||
|
tm->tm_year = bcd2bin(regs[9]) + 100;
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
u8 regs[7];
|
||
|
int err;
|
||
|
|
||
|
err = regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
|
||
|
PCF8523_CONTROL1_STOP, PCF8523_CONTROL1_STOP);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
/* This will purposely overwrite PCF8523_SECONDS_OS */
|
||
|
regs[0] = bin2bcd(tm->tm_sec);
|
||
|
regs[1] = bin2bcd(tm->tm_min);
|
||
|
regs[2] = bin2bcd(tm->tm_hour);
|
||
|
regs[3] = bin2bcd(tm->tm_mday);
|
||
|
regs[4] = tm->tm_wday;
|
||
|
regs[5] = bin2bcd(tm->tm_mon + 1);
|
||
|
regs[6] = bin2bcd(tm->tm_year - 100);
|
||
|
|
||
|
err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_SECONDS, regs,
|
||
|
sizeof(regs));
|
||
|
if (err < 0) {
|
||
|
/*
|
||
|
* If the time cannot be set, restart the RTC anyway. Note
|
||
|
* that errors are ignored if the RTC cannot be started so
|
||
|
* that we have a chance to propagate the original error.
|
||
|
*/
|
||
|
regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
|
||
|
PCF8523_CONTROL1_STOP, 0);
|
||
|
return err;
|
||
|
}
|
||
|
|
||
|
return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
|
||
|
PCF8523_CONTROL1_STOP, 0);
|
||
|
}
|
||
|
|
||
|
static int pcf8523_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
u8 regs[4];
|
||
|
u32 value;
|
||
|
int err;
|
||
|
|
||
|
err = regmap_bulk_read(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
|
||
|
sizeof(regs));
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
tm->time.tm_sec = 0;
|
||
|
tm->time.tm_min = bcd2bin(regs[0] & 0x7F);
|
||
|
tm->time.tm_hour = bcd2bin(regs[1] & 0x3F);
|
||
|
tm->time.tm_mday = bcd2bin(regs[2] & 0x3F);
|
||
|
tm->time.tm_wday = bcd2bin(regs[3] & 0x7);
|
||
|
|
||
|
err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL1, &value);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
tm->enabled = !!(value & PCF8523_CONTROL1_AIE);
|
||
|
|
||
|
err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL2, &value);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
tm->pending = !!(value & PCF8523_CONTROL2_AF);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int pcf8523_irq_enable(struct device *dev, unsigned int enabled)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
|
||
|
return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL1,
|
||
|
PCF8523_CONTROL1_AIE, enabled ?
|
||
|
PCF8523_CONTROL1_AIE : 0);
|
||
|
}
|
||
|
|
||
|
static int pcf8523_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
u8 regs[5];
|
||
|
int err;
|
||
|
|
||
|
err = pcf8523_irq_enable(dev, 0);
|
||
|
if (err)
|
||
|
return err;
|
||
|
|
||
|
err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL2, 0);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
regs[0] = bin2bcd(tm->time.tm_min);
|
||
|
regs[1] = bin2bcd(tm->time.tm_hour);
|
||
|
regs[2] = bin2bcd(tm->time.tm_mday);
|
||
|
regs[3] = ALARM_DIS;
|
||
|
|
||
|
err = regmap_bulk_write(pcf8523->regmap, PCF8523_REG_MINUTE_ALARM, regs,
|
||
|
sizeof(regs));
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
if (tm->enabled)
|
||
|
return pcf8523_irq_enable(dev, tm->enabled);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int pcf8523_param_get(struct device *dev, struct rtc_param *param)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
int ret;
|
||
|
u32 value;
|
||
|
|
||
|
switch(param->param) {
|
||
|
|
||
|
case RTC_PARAM_BACKUP_SWITCH_MODE:
|
||
|
ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
|
||
|
if (ret < 0)
|
||
|
return ret;
|
||
|
|
||
|
value = FIELD_GET(PCF8523_CONTROL3_PM, value);
|
||
|
|
||
|
switch(value) {
|
||
|
case 0x0:
|
||
|
case 0x4:
|
||
|
param->uvalue = RTC_BSM_LEVEL;
|
||
|
break;
|
||
|
case 0x1:
|
||
|
case 0x5:
|
||
|
param->uvalue = RTC_BSM_DIRECT;
|
||
|
break;
|
||
|
case PCF8523_PM_STANDBY:
|
||
|
param->uvalue = RTC_BSM_STANDBY;
|
||
|
break;
|
||
|
default:
|
||
|
param->uvalue = RTC_BSM_DISABLED;
|
||
|
}
|
||
|
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int pcf8523_param_set(struct device *dev, struct rtc_param *param)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
u8 mode;
|
||
|
|
||
|
switch(param->param) {
|
||
|
case RTC_PARAM_BACKUP_SWITCH_MODE:
|
||
|
switch (param->uvalue) {
|
||
|
case RTC_BSM_DISABLED:
|
||
|
mode = 0x2;
|
||
|
break;
|
||
|
case RTC_BSM_DIRECT:
|
||
|
mode = 0x1;
|
||
|
break;
|
||
|
case RTC_BSM_LEVEL:
|
||
|
mode = 0x0;
|
||
|
break;
|
||
|
case RTC_BSM_STANDBY:
|
||
|
mode = PCF8523_PM_STANDBY;
|
||
|
break;
|
||
|
default:
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
return regmap_update_bits(pcf8523->regmap, PCF8523_REG_CONTROL3,
|
||
|
PCF8523_CONTROL3_PM,
|
||
|
FIELD_PREP(PCF8523_CONTROL3_PM, mode));
|
||
|
|
||
|
break;
|
||
|
|
||
|
default:
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
|
||
|
unsigned long arg)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
unsigned int flags = 0;
|
||
|
u32 value;
|
||
|
int ret;
|
||
|
|
||
|
switch (cmd) {
|
||
|
case RTC_VL_READ:
|
||
|
ret = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
|
||
|
if (ret < 0)
|
||
|
return ret;
|
||
|
|
||
|
if (value & PCF8523_CONTROL3_BLF)
|
||
|
flags |= RTC_VL_BACKUP_LOW;
|
||
|
|
||
|
ret = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
|
||
|
if (ret < 0)
|
||
|
return ret;
|
||
|
|
||
|
if (value & PCF8523_SECONDS_OS)
|
||
|
flags |= RTC_VL_DATA_INVALID;
|
||
|
|
||
|
return put_user(flags, (unsigned int __user *)arg);
|
||
|
|
||
|
default:
|
||
|
return -ENOIOCTLCMD;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
static int pcf8523_rtc_read_offset(struct device *dev, long *offset)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
int err;
|
||
|
u32 value;
|
||
|
s8 val;
|
||
|
|
||
|
err = regmap_read(pcf8523->regmap, PCF8523_REG_OFFSET, &value);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
/* sign extend the 7-bit offset value */
|
||
|
val = value << 1;
|
||
|
*offset = (value & PCF8523_OFFSET_MODE ? 4069 : 4340) * (val >> 1);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int pcf8523_rtc_set_offset(struct device *dev, long offset)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523 = dev_get_drvdata(dev);
|
||
|
long reg_m0, reg_m1;
|
||
|
u32 value;
|
||
|
|
||
|
reg_m0 = clamp(DIV_ROUND_CLOSEST(offset, 4340), -64L, 63L);
|
||
|
reg_m1 = clamp(DIV_ROUND_CLOSEST(offset, 4069), -64L, 63L);
|
||
|
|
||
|
if (abs(reg_m0 * 4340 - offset) < abs(reg_m1 * 4069 - offset))
|
||
|
value = reg_m0 & 0x7f;
|
||
|
else
|
||
|
value = (reg_m1 & 0x7f) | PCF8523_OFFSET_MODE;
|
||
|
|
||
|
return regmap_write(pcf8523->regmap, PCF8523_REG_OFFSET, value);
|
||
|
}
|
||
|
|
||
|
static const struct rtc_class_ops pcf8523_rtc_ops = {
|
||
|
.read_time = pcf8523_rtc_read_time,
|
||
|
.set_time = pcf8523_rtc_set_time,
|
||
|
.read_alarm = pcf8523_rtc_read_alarm,
|
||
|
.set_alarm = pcf8523_rtc_set_alarm,
|
||
|
.alarm_irq_enable = pcf8523_irq_enable,
|
||
|
.ioctl = pcf8523_rtc_ioctl,
|
||
|
.read_offset = pcf8523_rtc_read_offset,
|
||
|
.set_offset = pcf8523_rtc_set_offset,
|
||
|
.param_get = pcf8523_param_get,
|
||
|
.param_set = pcf8523_param_set,
|
||
|
};
|
||
|
|
||
|
static const struct regmap_config regmap_config = {
|
||
|
.reg_bits = 8,
|
||
|
.val_bits = 8,
|
||
|
.max_register = 0x13,
|
||
|
};
|
||
|
|
||
|
static int pcf8523_probe(struct i2c_client *client)
|
||
|
{
|
||
|
struct pcf8523 *pcf8523;
|
||
|
struct rtc_device *rtc;
|
||
|
bool wakeup_source = false;
|
||
|
u32 value;
|
||
|
int err;
|
||
|
|
||
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
|
||
|
return -ENODEV;
|
||
|
|
||
|
pcf8523 = devm_kzalloc(&client->dev, sizeof(struct pcf8523), GFP_KERNEL);
|
||
|
if (!pcf8523)
|
||
|
return -ENOMEM;
|
||
|
|
||
|
pcf8523->regmap = devm_regmap_init_i2c(client, ®map_config);
|
||
|
if (IS_ERR(pcf8523->regmap))
|
||
|
return PTR_ERR(pcf8523->regmap);
|
||
|
|
||
|
i2c_set_clientdata(client, pcf8523);
|
||
|
|
||
|
rtc = devm_rtc_allocate_device(&client->dev);
|
||
|
if (IS_ERR(rtc))
|
||
|
return PTR_ERR(rtc);
|
||
|
pcf8523->rtc = rtc;
|
||
|
|
||
|
err = pcf8523_load_capacitance(pcf8523, client->dev.of_node);
|
||
|
if (err < 0)
|
||
|
dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
|
||
|
err);
|
||
|
|
||
|
err = regmap_read(pcf8523->regmap, PCF8523_REG_SECONDS, &value);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
if (value & PCF8523_SECONDS_OS) {
|
||
|
err = regmap_read(pcf8523->regmap, PCF8523_REG_CONTROL3, &value);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
if (FIELD_GET(PCF8523_CONTROL3_PM, value) == PCF8523_PM_STANDBY) {
|
||
|
err = regmap_write(pcf8523->regmap, PCF8523_REG_CONTROL3,
|
||
|
value & ~PCF8523_CONTROL3_PM);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
rtc->ops = &pcf8523_rtc_ops;
|
||
|
rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
|
||
|
rtc->range_max = RTC_TIMESTAMP_END_2099;
|
||
|
set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
|
||
|
clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
|
||
|
|
||
|
if (client->irq > 0) {
|
||
|
unsigned long irqflags = IRQF_TRIGGER_LOW;
|
||
|
|
||
|
if (dev_fwnode(&client->dev))
|
||
|
irqflags = 0;
|
||
|
|
||
|
err = regmap_write(pcf8523->regmap, PCF8523_TMR_CLKOUT_CTRL, 0x38);
|
||
|
if (err < 0)
|
||
|
return err;
|
||
|
|
||
|
err = devm_request_threaded_irq(&client->dev, client->irq,
|
||
|
NULL, pcf8523_irq,
|
||
|
IRQF_SHARED | IRQF_ONESHOT | irqflags,
|
||
|
dev_name(&rtc->dev), pcf8523);
|
||
|
if (err)
|
||
|
return err;
|
||
|
|
||
|
dev_pm_set_wake_irq(&client->dev, client->irq);
|
||
|
}
|
||
|
|
||
|
wakeup_source = of_property_read_bool(client->dev.of_node, "wakeup-source");
|
||
|
if (client->irq > 0 || wakeup_source)
|
||
|
device_init_wakeup(&client->dev, true);
|
||
|
|
||
|
return devm_rtc_register_device(rtc);
|
||
|
}
|
||
|
|
||
|
static const struct i2c_device_id pcf8523_id[] = {
|
||
|
{ "pcf8523", 0 },
|
||
|
{ }
|
||
|
};
|
||
|
MODULE_DEVICE_TABLE(i2c, pcf8523_id);
|
||
|
|
||
|
static const struct of_device_id pcf8523_of_match[] = {
|
||
|
{ .compatible = "nxp,pcf8523" },
|
||
|
{ .compatible = "microcrystal,rv8523" },
|
||
|
{ }
|
||
|
};
|
||
|
MODULE_DEVICE_TABLE(of, pcf8523_of_match);
|
||
|
|
||
|
static struct i2c_driver pcf8523_driver = {
|
||
|
.driver = {
|
||
|
.name = "rtc-pcf8523",
|
||
|
.of_match_table = pcf8523_of_match,
|
||
|
},
|
||
|
.probe_new = pcf8523_probe,
|
||
|
.id_table = pcf8523_id,
|
||
|
};
|
||
|
module_i2c_driver(pcf8523_driver);
|
||
|
|
||
|
MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
|
||
|
MODULE_DESCRIPTION("NXP PCF8523 RTC driver");
|
||
|
MODULE_LICENSE("GPL v2");
|