Here's an updated patch with the changes requested by Andrew.

Major points of the update include:

   - Moved PCF2123 section in Kconfig to be inside the
     "if SPI_MASTER" blob, to take care of dependencies.

   - Changed udelay() to macro w/ comment, and shifted to
     using ndelay() instead due to 30 nsec requirement,
     not 30 usec as was originally coded.

   - Bypass delay if spi_*() commands fail.

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

drivers/rtc/Kconfig

@@ -224,15 +224,6 @@ config RTC_DRV_PCF8583
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-pcf8583.
 
-config RTC_DRV_PCF2123
-	tristate "NXP PCF2123"
-	help
-	  If you say yes here you get support for the NXP PCF2123
-	  RTC chip.
-
-	  This driver can also be built as a module. If so, the module
-	  will be called rtc-pcf2123.
-
 config RTC_DRV_M41T80
 	tristate "ST M41T62/65/M41T80/81/82/83/84/85/87"
 	help
@@ -387,6 +378,15 @@ config RTC_DRV_DS3234
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-ds3234.
 
+config RTC_DRV_PCF2123
+	tristate "NXP PCF2123"
+	help
+	  If you say yes here you get support for the NXP PCF2123
+	  RTC chip.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-pcf2123.
+
 endif # SPI_MASTER
 
 comment "Platform RTC drivers"

drivers/rtc/rtc-pcf2123.c

@@ -23,7 +23,7 @@
 #include <linux/workqueue.h>
 #include <linux/spi/spi.h>
 
-#define DRV_VERSION "0.2"
+#define DRV_VERSION "0.3"
 
 #define PCF2123_REG_CTRL1	0x00 /* Control Register 1 */
 #define PCF2123_REG_CTRL2	0x01 /* Control Register 2 */
@@ -39,6 +39,9 @@
 #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()	{ ndelay(30); }
+
 static struct spi_driver pcf2123_driver;
 
 struct pcf2123_plat_data {
@@ -54,9 +57,9 @@ static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	txbuf[0] = PCF2123_CMD_R(PCF2123_REG_SC);
 	ret = spi_write_then_read(spi, txbuf, sizeof(txbuf),
 			rxbuf, sizeof(rxbuf));
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		return ret;
+	PCF2123_DELAY_TREC();
 
 	tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F);
 	tm->tm_min = bcd2bin(rxbuf[1] & 0x7F);
@@ -99,9 +102,9 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_CTRL1);
 	txbuf[1] = 0x20;
 	ret = spi_write(spi, txbuf, 2);
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		return ret;
+	PCF2123_DELAY_TREC();
 
 	/* Set the new time */
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_SC);
@@ -114,17 +117,17 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
 
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		return ret;
+	PCF2123_DELAY_TREC();
 
 	/* Start the counter */
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_CTRL1);
 	txbuf[1] = 0x00;
 	ret = spi_write(spi, txbuf, 2);
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		return ret;
+	PCF2123_DELAY_TREC();
 
 	return 0;
 }
@@ -150,24 +153,24 @@ static int __devinit pcf2123_probe(struct spi_device *spi)
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_CTRL1);
 	txbuf[1] = 0x58;
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		return ret;
+	PCF2123_DELAY_TREC();
 
 	/* Stop the counter */
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_CTRL1);
 	txbuf[1] = 0x20;
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		return ret;
+	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));
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		goto kfree_exit;
+	PCF2123_DELAY_TREC();
 
 	if (!(rxbuf[0] & 0x20)) {
 		dev_err(&spi->dev, "not found.\n");
@@ -182,9 +185,9 @@ static int __devinit pcf2123_probe(struct spi_device *spi)
 	txbuf[0] = PCF2123_CMD_W(PCF2123_REG_CTRL1);
 	txbuf[1] = 0x00;
 	ret = spi_write(spi, txbuf, sizeof(txbuf));
-	udelay(30); /* Trec 30us */
 	if (ret < 0)
 		goto kfree_exit;
+	PCF2123_DELAY_TREC();
 
 	/* Finalize the initialization */
 	rtc = rtc_device_register(pcf2123_driver.driver.name, &spi->dev,