static int pcf8523_rtc_check_oscillator(struct i2c_client *client)
{
u8 value;
int err;
err = pcf8523_read(client, REG_SECONDS, &value);
if (err < 0)
return err;
if (value & REG_SECONDS_OS) {
/*
* If the oscillator was stopped, try to clear the flag. Upon
* power-up the flag is always set, but if we cannot clear it
* the oscillator isn't running properly for some reason. The
* sensible thing therefore is to return an error, signalling
* that the clock cannot be assumed to be correct.
*/
value &= ~REG_SECONDS_OS;
err = pcf8523_write(client, REG_SECONDS, value);
if (err < 0)
return err;
err = pcf8523_read(client, REG_SECONDS, &value);
if (err < 0)
return err;
if (value & REG_SECONDS_OS)
return -EAGAIN;
}
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 = REG_SECONDS, regs[7];
struct i2c_msg msgs[2];
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;
if (regs[0] & REG_SECONDS_OS) {
/*
* If the oscillator was stopped, try to clear the flag. Upon
* power-up the flag is always set, but if we cannot clear it
* the oscillator isn't running properly for some reason. The
* sensible thing therefore is to return an error, signalling
* that the clock cannot be assumed to be correct.
*/
regs[0] &= ~REG_SECONDS_OS;
err = pcf8523_write(client, REG_SECONDS, regs[0]);
if (err < 0)
return err;
err = pcf8523_read(client, REG_SECONDS, ®s[0]);
if (err < 0)
return err;
if (regs[0] & REG_SECONDS_OS)
return -EAGAIN;
}
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);
tm->tm_year = bcd2bin(regs[6]) + 100;
return rtc_valid_tm(tm);
}
static int pcf8523_switch_capacitance(struct i2c_client *client)
{
u8 value;
int err;
err = pcf8523_read(client, REG_CONTROL1, &value);
if (err < 0)
goto out;
value ^= REG_CONTROL1_CAP_SEL;
err = pcf8523_write(client, REG_CONTROL1, value);
out:
return err;
}
static int pcf8523_start_rtc(struct i2c_client *client)
{
u8 value;
int err;
err = pcf8523_read(client, REG_CONTROL1, &value);
if (err < 0)
return err;
value &= ~REG_CONTROL1_STOP;
err = pcf8523_write(client, REG_CONTROL1, value);
if (err < 0)
return err;
return 0;
}
static int pcf8523_set_pm(struct i2c_client *client, u8 pm)
{
u8 value;
int err;
err = pcf8523_read(client, REG_CONTROL3, &value);
if (err < 0)
return err;
value = (value & ~REG_CONTROL3_PM_MASK) | pm;
err = pcf8523_write(client, REG_CONTROL3, value);
if (err < 0)
return err;
return 0;
}
static int pcf8523_select_capacitance(struct i2c_client *client, bool high)
{
u8 value;
int err;
err = pcf8523_read(client, REG_CONTROL1, &value);
if (err < 0)
return err;
if (!high)
value &= ~REG_CONTROL1_CAP_SEL;
else
value |= REG_CONTROL1_CAP_SEL;
err = pcf8523_write(client, REG_CONTROL1, value);
if (err < 0)
return err;
return err;
}