console: don't prefer first registered if DT specifies stdout-path

[cascardo/linux.git] / drivers / rtc / rtc-pcf85063.c

diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index e8ddbb3..efb0a08 100644 (file)
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -16,6 +16,16 @@
 #include <linux/rtc.h>
 #include <linux/module.h>
 
+/*
+ * Information for this driver was pulled from the following datasheets.
+ *
+ *  http://www.nxp.com/documents/data_sheet/PCF85063A.pdf
+ *  http://www.nxp.com/documents/data_sheet/PCF85063TP.pdf
+ *
+ *  PCF85063A -- Rev. 6 — 18 November 2015
+ *  PCF85063TP -- Rev. 4 — 6 May 2015
+*/
+
 #define PCF85063_REG_CTRL1             0x00 /* status */
 #define PCF85063_REG_CTRL1_STOP                BIT(5)
 #define PCF85063_REG_CTRL2             0x01
@@ -55,10 +65,22 @@ static int pcf85063_stop_clock(struct i2c_client *client, u8 *ctrl1)
        return 0;
 }
 
-/*
- * In the routines that deal directly with the pcf85063 hardware, we use
- * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
- */
+static int pcf85063_start_clock(struct i2c_client *client, u8 ctrl1)
+{
+       s32 ret;
+
+       /* start the clock */
+       ctrl1 &= PCF85063_REG_CTRL1_STOP;
+
+       ret = i2c_smbus_write_byte_data(client, PCF85063_REG_CTRL1, ctrl1);
+       if (ret < 0) {
+               dev_err(&client->dev, "Failing to start the clock\n");
+               return -EIO;
+       }
+
+       return 0;
+}
+
 static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
        int rc;
@@ -90,8 +112,7 @@ static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
        tm->tm_wday = regs[4] & 0x07;
        tm->tm_mon = bcd2bin(regs[5] & 0x1F) - 1; /* rtc mn 1-12 */
        tm->tm_year = bcd2bin(regs[6]);
-       if (tm->tm_year < 70)
-               tm->tm_year += 100;     /* assume we are in 1970...2069 */
+       tm->tm_year += 100;
 
        return rtc_valid_tm(tm);
 }
@@ -99,13 +120,17 @@ static int pcf85063_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
        int rc;
-       u8 regs[8];
+       u8 regs[7];
+       u8 ctrl1;
+
+       if ((tm->tm_year < 100) || (tm->tm_year > 199))
+               return -EINVAL;
 
        /*
         * to accurately set the time, reset the divider chain and keep it in
         * reset state until all time/date registers are written
         */
-       rc = pcf85063_stop_clock(client, &regs[7]);
+       rc = pcf85063_stop_clock(client, &ctrl1);
        if (rc != 0)
                return rc;
 
@@ -125,14 +150,7 @@ static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
        regs[5] = bin2bcd(tm->tm_mon + 1);
 
        /* year and century */
-       regs[6] = bin2bcd(tm->tm_year % 100);
-
-       /*
-        * after all time/date registers are written, let the 'address auto
-        * increment' feature wrap around and write register CTRL1 to re-enable
-        * the clock divider chain again
-        */
-       regs[7] &= ~PCF85063_REG_CTRL1_STOP;
+       regs[6] = bin2bcd(tm->tm_year - 100);
 
        /* write all registers at once */
        rc = i2c_smbus_write_i2c_block_data(client, PCF85063_REG_SC,
@@ -142,6 +160,15 @@ static int pcf85063_set_datetime(struct i2c_client *client, struct rtc_time *tm)
                return rc;
        }
 
+       /*
+        * Write the control register as a separate action since the size of
+        * the register space is different between the PCF85063TP and
+        * PCF85063A devices.  The rollover point can not be used.
+        */
+       rc = pcf85063_start_clock(client, ctrl1);
+       if (rc != 0)
+               return rc;
+
        return 0;
 }