> static inline void pcf2123_delay_trec(void)

You're right ... much cleaner.  Proof that one should not code over
vacation.  :-)  Full patch re-created and attached.

Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/rtc/rtc-pcf2123.c

@@ -39,15 +39,22 @@
 #define PCF2123_CMD_W(addr)	(((addr) & 0x0F) | 0x40)  /* single write */
 #define PCF2123_CMD_R(addr)	(((addr) & 0x0F) | 0x90)  /* single read */
 
-/* The Trec (chip enable recovery time) is specified by the PCF2123 */
-#define PCF2123_DELAY_TREC()	do { ndelay(30); } while (0)
-
 static struct spi_driver pcf2123_driver;
 
 struct pcf2123_plat_data {
 	struct rtc_device *rtc;
 };
 
+/*
+ * Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
+ * is released properly after an SPI write.  This function should be
+ * called after EVERY read/write call over SPI.
+ */
+static inline void pcf2123_delay_trec(void)
+{
+	ndelay(30);
+}
+
 static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct spi_device *spi = to_spi_device(dev);
@@ -59,7 +66,7 @@ static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
 			rxbuf, sizeof(rxbuf));
 	if (ret < 0)
 		return ret;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
 	tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
@@ -104,7 +111,7 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	ret = spi_write(spi, txbuf, 2);
 	if (ret < 0)
 		return ret;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	/* Set the new time */
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_SC);
@@ -119,7 +126,7 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
 	if (ret < 0)
 		return ret;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	/* Start the counter */
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_CTRL1);
@@ -127,7 +134,7 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	ret = spi_write(spi, txbuf, 2);
 	if (ret < 0)
 		return ret;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	return 0;
 }
@@ -155,7 +162,7 @@ static int __devinit pcf2123_probe(struct spi_device *spi)
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
 	if (ret < 0)
 		return ret;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	/* Stop the counter */
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_CTRL1);
@@ -163,14 +170,14 @@ static int __devinit pcf2123_probe(struct spi_device *spi)
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
 	if (ret < 0)
 		return ret;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	/* See if the counter was actually stopped */
 	txbuf[0] = PCF2123_CMD_R(PCF2123_REG_CTRL1);
 	ret = spi_write_then_read(spi, txbuf, 1, rxbuf, sizeof(rxbuf));
 	if (ret < 0)
 		goto kfree_exit;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	if (!(rxbuf[0] & 0x20)) {
 		dev_err(&spi->dev, "not found.\n");
@@ -187,7 +194,7 @@ static int __devinit pcf2123_probe(struct spi_device *spi)
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
 	if (ret < 0)
 		goto kfree_exit;
-	PCF2123_DELAY_TREC();
+	pcf2123_delay_trec();
 
 	/* Finalize the initialization */
 	rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,