SPI API improvements

[oweals/u-boot.git] / drivers / rtc / ds1306.c

diff --git a/drivers/rtc/ds1306.c b/drivers/rtc/ds1306.c
index 1c8ac7f2927997989bf4a1738e7616e9e5d70290..29854fc7c4cf6f4e67b645b5333e11a45beeec62 100644 (file)
--- a/drivers/rtc/ds1306.c
+++ b/drivers/rtc/ds1306.c
@@ -62,13 +62,6 @@
 
 #define        RTC_USER_RAM_BASE       0x20
 
-/*
- * External table of chip select functions (see the appropriate board
- * support for the actual definition of the table).
- */
-extern spi_chipsel_type spi_chipsel[];
-extern int spi_chipsel_cnt;
-
 static unsigned int bin2bcd (unsigned int n);
 static unsigned char bcd2bin (unsigned char c);
 
@@ -305,11 +298,29 @@ void rtc_reset (void)
 static unsigned char rtc_read (unsigned char reg);
 static void rtc_write (unsigned char reg, unsigned char val);
 
+static struct spi_slave *slave;
+
 /* read clock time from DS1306 and return it in *tmp */
 int rtc_get (struct rtc_time *tmp)
 {
        unsigned char sec, min, hour, mday, wday, mon, year;
 
+       /*
+        * Assuming Vcc = 2.0V (lowest speed)
+        *
+        * REVISIT: If we add an rtc_init() function we can do this
+        * step just once.
+        */
+       if (!slave) {
+               slave = spi_setup_slave(0, CFG_SPI_RTC_DEVID, 600000,
+                               SPI_MODE_3 | SPI_CS_HIGH);
+               if (!slave)
+                       return;
+       }
+
+       if (spi_claim_bus(slave))
+               return;
+
        sec = rtc_read (RTC_SECONDS);
        min = rtc_read (RTC_MINUTES);
        hour = rtc_read (RTC_HOURS);
@@ -318,6 +329,8 @@ int rtc_get (struct rtc_time *tmp)
        mon = rtc_read (RTC_MONTH);
        year = rtc_read (RTC_YEAR);
 
+       spi_release_bus(slave);
+
        debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
               "hr: %02x min: %02x sec: %02x\n",
               year, mon, mday, wday, hour, min, sec);
@@ -360,6 +373,17 @@ int rtc_get (struct rtc_time *tmp)
 /* set clock time from *tmp in DS1306 RTC */
 void rtc_set (struct rtc_time *tmp)
 {
+       /* Assuming Vcc = 2.0V (lowest speed) */
+       if (!slave) {
+               slave = spi_setup_slave(0, CFG_SPI_RTC_DEVID, 600000,
+                               SPI_MODE_3 | SPI_CS_HIGH);
+               if (!slave)
+                       return;
+       }
+
+       if (spi_claim_bus(slave))
+               return;
+
        debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
               tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
               tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
@@ -371,6 +395,8 @@ void rtc_set (struct rtc_time *tmp)
        rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
        rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
        rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
+
+       spi_release_bus(slave);
 }
 
 /* ------------------------------------------------------------------------- */
@@ -378,6 +404,17 @@ void rtc_set (struct rtc_time *tmp)
 /* reset the DS1306 */
 void rtc_reset (void)
 {
+       /* Assuming Vcc = 2.0V (lowest speed) */
+       if (!slave) {
+               slave = spi_setup_slave(0, CFG_SPI_RTC_DEVID, 600000,
+                               SPI_MODE_3 | SPI_CS_HIGH);
+               if (!slave)
+                       return;
+       }
+
+       if (spi_claim_bus(slave))
+               return;
+
        /* clear the control register */
        rtc_write (RTC_CONTROL, 0x00);  /* 1st step: reset WP */
        rtc_write (RTC_CONTROL, 0x00);  /* 2nd step: reset 1Hz, AIE1, AIE0 */
@@ -391,22 +428,18 @@ void rtc_reset (void)
        rtc_write (RTC_HOURS_ALARM1, 0x00);
        rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
        rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
+
+       spi_release_bus(slave);
 }
 
 /* ------------------------------------------------------------------------- */
 
 static unsigned char rtc_read (unsigned char reg)
 {
-       unsigned char dout[2];  /* SPI Output Data Bytes */
-       unsigned char din[2];   /* SPI Input Data Bytes */
-
-       dout[0] = reg;
+       int ret;
 
-       if (spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din) != 0) {
-               return 0;
-       } else {
-               return din[1];
-       }
+       ret = spi_w8r8(slave, reg);
+       return ret < 0 ? 0 : ret;
 }
 
 /* ------------------------------------------------------------------------- */
@@ -419,7 +452,7 @@ static void rtc_write (unsigned char reg, unsigned char val)
        dout[0] = 0x80 | reg;
        dout[1] = val;
 
-       spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din);
+       spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
 }
 
 #endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */