diff options
| -rw-r--r-- | drivers/rtc/rtc-pcf8563.c | 40 |
1 files changed, 34 insertions, 6 deletions
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c index 4b72b8ef5d66..038118bbfaea 100644 --- a/drivers/rtc/rtc-pcf8563.c +++ b/drivers/rtc/rtc-pcf8563.c @@ -53,6 +53,25 @@ I2C_CLIENT_INSMOD; #define PCF8563_SC_LV 0x80 /* low voltage */ #define PCF8563_MO_C 0x80 /* century */ +struct pcf8563 { + struct i2c_client client; + /* + * The meaning of MO_C bit varies by the chip type. + * From PCF8563 datasheet: this bit is toggled when the years + * register overflows from 99 to 00 + * 0 indicates the century is 20xx + * 1 indicates the century is 19xx + * From RTC8564 datasheet: this bit indicates change of + * century. When the year digit data overflows from 99 to 00, + * this bit is set. By presetting it to 0 while still in the + * 20th century, it will be set in year 2000, ... + * There seems no reliable way to know how the system use this + * bit. So let's do it heuristically, assuming we are live in + * 1970...2069. + */ + int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ +}; + static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind); static int pcf8563_detach(struct i2c_client *client); @@ -62,6 +81,7 @@ static int pcf8563_detach(struct i2c_client *client); */ static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) { + struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client); unsigned char buf[13] = { PCF8563_REG_ST1 }; struct i2c_msg msgs[] = { @@ -94,8 +114,12 @@ static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) tm->tm_mday = BCD2BIN(buf[PCF8563_REG_DM] & 0x3F); tm->tm_wday = buf[PCF8563_REG_DW] & 0x07; tm->tm_mon = BCD2BIN(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */ - tm->tm_year = BCD2BIN(buf[PCF8563_REG_YR]) - + (buf[PCF8563_REG_MO] & PCF8563_MO_C ? 0 : 100); + tm->tm_year = BCD2BIN(buf[PCF8563_REG_YR]); + if (tm->tm_year < 70) + tm->tm_year += 100; /* assume we are in 1970...2069 */ + /* detect the polarity heuristically. see note above. */ + pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ? + (tm->tm_year >= 100) : (tm->tm_year < 100); dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, " "mday=%d, mon=%d, year=%d, wday=%d\n", @@ -114,6 +138,7 @@ static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) { + struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client); int i, err; unsigned char buf[9]; @@ -135,7 +160,7 @@ static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) /* year and century */ buf[PCF8563_REG_YR] = BIN2BCD(tm->tm_year % 100); - if (tm->tm_year < 100) + if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100)) buf[PCF8563_REG_MO] |= PCF8563_MO_C; buf[PCF8563_REG_DW] = tm->tm_wday & 0x07; @@ -248,6 +273,7 @@ static struct i2c_driver pcf8563_driver = { static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind) { + struct pcf8563 *pcf8563; struct i2c_client *client; struct rtc_device *rtc; @@ -260,11 +286,12 @@ static int pcf8563_probe(struct i2c_adapter *adapter, int address, int kind) goto exit; } - if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) { + if (!(pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL))) { err = -ENOMEM; goto exit; } + client = &pcf8563->client; client->addr = address; client->driver = &pcf8563_driver; client->adapter = adapter; @@ -301,7 +328,7 @@ exit_detach: i2c_detach_client(client); exit_kfree: - kfree(client); + kfree(pcf8563); exit: return err; @@ -309,6 +336,7 @@ exit: static int pcf8563_detach(struct i2c_client *client) { + struct pcf8563 *pcf8563 = container_of(client, struct pcf8563, client); int err; struct rtc_device *rtc = i2c_get_clientdata(client); @@ -318,7 +346,7 @@ static int pcf8563_detach(struct i2c_client *client) if ((err = i2c_detach_client(client))) return err; - kfree(client); + kfree(pcf8563); return 0; } |