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linux/drivers/rtc/rtc-pcf8523.c
Alexandre Belloni 4aa90c036d rtc: pcf8523: rename register and bit defines 
arch/arm/mach-ixp4xx/include/mach/platform.h now gets included indirectly
and defines REG_OFFSET. Rename the register and bit definition to something
specific to the driver.

Fixes: 7fd70c65fa ("ARM: irqstat: Get rid of duplicated declaration")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210710211431.1393589-1-alexandre.belloni@bootlin.com
2021-07-10 23:18:30 +02:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Avionic Design GmbH
*/
#include <linux/bcd.h>
#include <linux/i2c.h>
#include <linux/module.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_BLD BIT(7) /* battery low detection disabled */
#define PCF8523_CONTROL3_PM_VDD BIT(6) /* switch-over disabled */
#define PCF8523_CONTROL3_PM_DSM BIT(5) /* direct switching mode */
#define PCF8523_CONTROL3_PM_MASK 0xe0
#define PCF8523_CONTROL3_BLF BIT(2) /* battery low bit, read-only */
#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 i2c_client *client;
};
static int pcf8523_read(struct i2c_client *client, u8 reg, u8 *valuep)
{
struct i2c_msg msgs[2];
u8 value = 0;
int err;
msgs[0].addr = client->addr;
msgs[0].flags = 0;
msgs[0].len = sizeof(reg);
msgs[0].buf = &reg;
msgs[1].addr = client->addr;
msgs[1].flags = I2C_M_RD;
msgs[1].len = sizeof(value);
msgs[1].buf = &value;
err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (err < 0)
return err;
*valuep = value;
return 0;
}
static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value)
{
u8 buffer[2] = { reg, value };
struct i2c_msg msg;
int err;
msg.addr = client->addr;
msg.flags = 0;
msg.len = sizeof(buffer);
msg.buf = buffer;
err = i2c_transfer(client->adapter, &msg, 1);
if (err < 0)
return err;
return 0;
}
static int pcf8523_voltage_low(struct i2c_client *client)
{
u8 value;
int err;
err = pcf8523_read(client, PCF8523_REG_CONTROL3, &value);
if (err < 0)
return err;
return !!(value & PCF8523_CONTROL3_BLF);
}
static int pcf8523_load_capacitance(struct i2c_client *client)
{
u32 load;
u8 value;
int err;
err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
if (err < 0)
return err;
load = 12500;
of_property_read_u32(client->dev.of_node, "quartz-load-femtofarads",
&load);
switch (load) {
default:
dev_warn(&client->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 12500",
load);
fallthrough;
case 12500:
value |= PCF8523_CONTROL1_CAP_SEL;
break;
case 7000:
value &= ~PCF8523_CONTROL1_CAP_SEL;
break;
}
err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
return err;
}
static int pcf8523_set_pm(struct i2c_client *client, u8 pm)
{
u8 value;
int err;
err = pcf8523_read(client, PCF8523_REG_CONTROL3, &value);
if (err < 0)
return err;
value = (value & ~PCF8523_CONTROL3_PM_MASK) | pm;
err = pcf8523_write(client, PCF8523_REG_CONTROL3, value);
if (err < 0)
return err;
return 0;
}
static irqreturn_t pcf8523_irq(int irq, void *dev_id)
{
struct pcf8523 *pcf8523 = i2c_get_clientdata(dev_id);
u8 value;
int err;
err = pcf8523_read(pcf8523->client, PCF8523_REG_CONTROL2, &value);
if (err < 0)
return IRQ_HANDLED;
if (value & PCF8523_CONTROL2_AF) {
value &= ~PCF8523_CONTROL2_AF;
pcf8523_write(pcf8523->client, PCF8523_REG_CONTROL2, value);
rtc_update_irq(pcf8523->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int pcf8523_stop_rtc(struct i2c_client *client)
{
u8 value;
int err;
err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
if (err < 0)
return err;
value |= PCF8523_CONTROL1_STOP;
err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
if (err < 0)
return err;
return 0;
}
static int pcf8523_start_rtc(struct i2c_client *client)
{
u8 value;
int err;
err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
if (err < 0)
return err;
value &= ~PCF8523_CONTROL1_STOP;
err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
if (err < 0)
return err;
return 0;
}
static int pcf8523_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
u8 start = PCF8523_REG_SECONDS, regs[7];
struct i2c_msg msgs[2];
int err;
err = pcf8523_voltage_low(client);
if (err < 0) {
return err;
} else if (err > 0) {
dev_err(dev, "low voltage detected, time is unreliable\n");
return -EINVAL;
}
msgs[0].addr = client->addr;
msgs[0].flags = 0;
msgs[0].len = 1;
msgs[0].buf = &start;
msgs[1].addr = client->addr;
msgs[1].flags = I2C_M_RD;
msgs[1].len = sizeof(regs);
msgs[1].buf = regs;
err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (err < 0)
return err;
if (regs[0] & PCF8523_SECONDS_OS)
return -EINVAL;
tm->tm_sec = bcd2bin(regs[0] & 0x7f);
tm->tm_min = bcd2bin(regs[1] & 0x7f);
tm->tm_hour = bcd2bin(regs[2] & 0x3f);
tm->tm_mday = bcd2bin(regs[3] & 0x3f);
tm->tm_wday = regs[4] & 0x7;
tm->tm_mon = bcd2bin(regs[5] & 0x1f) - 1;
tm->tm_year = bcd2bin(regs[6]) + 100;
return 0;
}
static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_msg msg;
u8 regs[8];
int err;
err = pcf8523_stop_rtc(client);
if (err < 0)
return err;
regs[0] = PCF8523_REG_SECONDS;
/* This will purposely overwrite PCF8523_SECONDS_OS */
regs[1] = bin2bcd(tm->tm_sec);
regs[2] = bin2bcd(tm->tm_min);
regs[3] = bin2bcd(tm->tm_hour);
regs[4] = bin2bcd(tm->tm_mday);
regs[5] = tm->tm_wday;
regs[6] = bin2bcd(tm->tm_mon + 1);
regs[7] = bin2bcd(tm->tm_year - 100);
msg.addr = client->addr;
msg.flags = 0;
msg.len = sizeof(regs);
msg.buf = regs;
err = i2c_transfer(client->adapter, &msg, 1);
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.
*/
pcf8523_start_rtc(client);
return err;
}
return pcf8523_start_rtc(client);
}
static int pcf8523_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
{
struct i2c_client *client = to_i2c_client(dev);
u8 start = PCF8523_REG_MINUTE_ALARM, regs[4];
struct i2c_msg msgs[2];
u8 value;
int err;
msgs[0].addr = client->addr;
msgs[0].flags = 0;
msgs[0].len = 1;
msgs[0].buf = &start;
msgs[1].addr = client->addr;
msgs[1].flags = I2C_M_RD;
msgs[1].len = sizeof(regs);
msgs[1].buf = regs;
err = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
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 = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
if (err < 0)
return err;
tm->enabled = !!(value & PCF8523_CONTROL1_AIE);
err = pcf8523_read(client, 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 i2c_client *client = to_i2c_client(dev);
u8 value;
int err;
err = pcf8523_read(client, PCF8523_REG_CONTROL1, &value);
if (err < 0)
return err;
value &= PCF8523_CONTROL1_AIE;
if (enabled)
value |= PCF8523_CONTROL1_AIE;
err = pcf8523_write(client, PCF8523_REG_CONTROL1, value);
if (err < 0)
return err;
return 0;
}
static int pcf8523_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_msg msg;
u8 regs[5];
int err;
err = pcf8523_irq_enable(dev, 0);
if (err)
return err;
err = pcf8523_write(client, PCF8523_REG_CONTROL2, 0);
if (err < 0)
return err;
/* The alarm has no seconds, round up to nearest minute */
if (tm->time.tm_sec) {
time64_t alarm_time = rtc_tm_to_time64(&tm->time);
alarm_time += 60 - tm->time.tm_sec;
rtc_time64_to_tm(alarm_time, &tm->time);
}
regs[0] = PCF8523_REG_MINUTE_ALARM;
regs[1] = bin2bcd(tm->time.tm_min);
regs[2] = bin2bcd(tm->time.tm_hour);
regs[3] = bin2bcd(tm->time.tm_mday);
regs[4] = ALARM_DIS;
msg.addr = client->addr;
msg.flags = 0;
msg.len = sizeof(regs);
msg.buf = regs;
err = i2c_transfer(client->adapter, &msg, 1);
if (err < 0)
return err;
if (tm->enabled)
return pcf8523_irq_enable(dev, tm->enabled);
return 0;
}
#ifdef CONFIG_RTC_INTF_DEV
static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
unsigned long arg)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned int flags = 0;
u8 value;
int ret;
switch (cmd) {
case RTC_VL_READ:
ret = pcf8523_voltage_low(client);
if (ret < 0)
return ret;
if (ret)
flags |= RTC_VL_BACKUP_LOW;
ret = pcf8523_read(client, 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;
}
}
#else
#define pcf8523_rtc_ioctl NULL
#endif
static int pcf8523_rtc_read_offset(struct device *dev, long *offset)
{
struct i2c_client *client = to_i2c_client(dev);
int err;
u8 value;
s8 val;
err = pcf8523_read(client, 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 i2c_client *client = to_i2c_client(dev);
long reg_m0, reg_m1;
u8 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 pcf8523_write(client, 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,
};
static int pcf8523_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct pcf8523 *pcf8523;
struct rtc_device *rtc;
bool wakeup_source = false;
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;
i2c_set_clientdata(client, pcf8523);
pcf8523->client = client;
err = pcf8523_load_capacitance(client);
if (err < 0)
dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
err);
err = pcf8523_set_pm(client, 0);
if (err < 0)
return err;
rtc = devm_rtc_allocate_device(&client->dev);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
pcf8523->rtc = rtc;
rtc->ops = &pcf8523_rtc_ops;
rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
rtc->range_max = RTC_TIMESTAMP_END_2099;
rtc->uie_unsupported = 1;
if (client->irq > 0) {
err = pcf8523_write(client, 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 | IRQF_TRIGGER_LOW,
dev_name(&rtc->dev), client);
if (err)
return err;
dev_pm_set_wake_irq(&client->dev, client->irq);
}
#ifdef CONFIG_OF
wakeup_source = of_property_read_bool(client->dev.of_node, "wakeup-source");
#endif
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);
#ifdef CONFIG_OF
static const struct of_device_id pcf8523_of_match[] = {
{ .compatible = "nxp,pcf8523" },
{ .compatible = "microcrystal,rv8523" },
{ }
};
MODULE_DEVICE_TABLE(of, pcf8523_of_match);
#endif
static struct i2c_driver pcf8523_driver = {
.driver = {
.name = "rtc-pcf8523",
.of_match_table = of_match_ptr(pcf8523_of_match),
},
.probe = 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");
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