Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight

[pandora-kernel.git] / drivers / spi / spi_lm70llp.c

diff --git a/drivers/spi/spi_lm70llp.c b/drivers/spi/spi_lm70llp.c
index 39d8d8a..568c781 100644 (file)
--- a/drivers/spi/spi_lm70llp.c
+++ b/drivers/spi/spi_lm70llp.c
@@ -1,5 +1,5 @@
 /*
- * spi_lm70llp.c - driver for lm70llp eval board for the LM70 sensor
+ * spi_lm70llp.c - driver for LM70EVAL-LLP board for the LM70 sensor
  *
  * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com>
  *
@@ -40,8 +40,12 @@
  * master controller driver.  The hwmon/lm70 driver is a "SPI protocol
  * driver", layered on top of this one and usable without the lm70llp.
  *
+ * Datasheet and Schematic:
  * The LM70 is a temperature sensor chip from National Semiconductor; its
  * datasheet is available at http://www.national.com/pf/LM/LM70.html
+ * The schematic for this particular board (the LM70EVAL-LLP) is
+ * available (on page 4) here:
+ *  http://www.national.com/appinfo/tempsensors/files/LM70LLPEVALmanual.pdf
  *
  * Also see Documentation/spi/spi-lm70llp.  The SPI<->parport code here is
  * (heavily) based on spi-butterfly by David Brownell.
@@ -64,7 +68,7 @@
  *
  * Note that parport pin 13 actually gets inverted by the transistor
  * arrangement which lets either the parport or the LM70 drive the
- * SI/SO signal.
+ * SI/SO signal (see the schematic for details).
  */
 
 #define DRVNAME                "spi-lm70llp"
@@ -106,12 +110,16 @@ static inline struct spi_lm70llp *spidev_to_pp(struct spi_device *spi)
 static inline void deassertCS(struct spi_lm70llp *pp)
 {
        u8 data = parport_read_data(pp->port);
+
+       data &= ~0x80;          /* pull D7/SI-out low while de-asserted */
        parport_write_data(pp->port, data | nCS);
 }
 
 static inline void assertCS(struct spi_lm70llp *pp)
 {
        u8 data = parport_read_data(pp->port);
+
+       data |= 0x80;           /* pull D7/SI-out high so lm70 drives SO-in */
        parport_write_data(pp->port, data & ~nCS);
 }
 
@@ -184,22 +192,7 @@ static void lm70_chipselect(struct spi_device *spi, int value)
  */
 static u32 lm70_txrx(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
 {
-       static u32 sio=0;
-       static int first_time=1;
-
-       /* First time: perform SPI bitbang and return the LSB of
-        * the result of the SPI call.
-        */
-       if (first_time) {
-               sio = bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
-               first_time=0;
-               return (sio & 0x00ff);
-       }
-       /* Return the MSB of the result of the SPI call */
-       else {
-               first_time=1;
-               return (sio >> 8);
-       }
+       return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
 }
 
 static void spi_lm70llp_attach(struct parport *p)
@@ -287,16 +280,15 @@ static void spi_lm70llp_attach(struct parport *p)
        pp->spidev_lm70 = spi_new_device(pp->bitbang.master, &pp->info);
        if (pp->spidev_lm70)
                dev_dbg(&pp->spidev_lm70->dev, "spidev_lm70 at %s\n",
-                               pp->spidev_lm70->dev.bus_id);
+                               dev_name(&pp->spidev_lm70->dev));
        else {
                printk(KERN_WARNING "%s: spi_new_device failed\n", DRVNAME);
                status = -ENODEV;
                goto out_bitbang_stop;
        }
-       pp->spidev_lm70->bits_per_word = 16;
+       pp->spidev_lm70->bits_per_word = 8;
 
        lm70llp = pp;
-
        return;
 
 out_bitbang_stop:
@@ -326,7 +318,6 @@ static void spi_lm70llp_detach(struct parport *p)
 
        /* power down */
        parport_write_data(pp->port, 0);
-       msleep(10);
 
        parport_release(pp->pd);
        parport_unregister_device(pp->pd);