minor spi_butterfly cleanup

Simplify the spi_butterfly driver by removing incomplete/unused support for
the second SPI bus, implemented by the USI controller.  This should make
this a clearer example of how to write a parport bitbang driver.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 58 deletions

diff --git a/drivers/spi/spi_butterfly.c b/drivers/spi/spi_butterfly.c
index 574d0fae4c59..0ee2b2090252 100644
--- a/drivers/spi/spi_butterfly.c
+++ b/drivers/spi/spi_butterfly.c
@@ -40,8 +40,6 @@
  * and use this custom parallel port cable.
  */
 
-#undef  HAVE_USI        /* nyet */
-
 
 /* DATA output bits (pins 2..9 == D0..D7) */
 #define butterfly_nreset (1 << 1)               /* pin 3 */
@@ -49,19 +47,13 @@
 #define spi_sck_bit     (1 << 0)                /* pin 2 */
 #define spi_mosi_bit    (1 << 7)                /* pin 9 */
 
-#define usi_sck_bit     (1 << 3)                /* pin 5 */
-#define usi_mosi_bit    (1 << 4)                /* pin 6 */
-
 #define vcc_bits        ((1 << 6) | (1 << 5))   /* pins 7, 8 */
 
 /* STATUS input bits */
 #define spi_miso_bit    PARPORT_STATUS_BUSY     /* pin 11 */
 
-#define usi_miso_bit    PARPORT_STATUS_PAPEROUT /* pin 12 */
-
 /* CONTROL output bits */
 #define spi_cs_bit      PARPORT_CONTROL_SELECT  /* pin 17 */
-/* USI uses no chipselect */
 
 
 
@@ -70,15 +62,6 @@ static inline struct butterfly *spidev_to_pp(struct spi_device *spi)
         return spi->controller_data;
 }
 
-static inline int is_usidev(struct spi_device *spi)
-{
-#ifdef  HAVE_USI
-        return spi->chip_select != 1;
-#else
-        return 0;
-#endif
-}
-
 
 struct butterfly {
         /* REVISIT ... for now, this must be first */
@@ -97,23 +80,13 @@ struct butterfly {
 
 /*----------------------------------------------------------------------*/
 
-/*
- * these routines may be slower than necessary because they're hiding
- * the fact that there are two different SPI busses on this cable: one
- * to the DataFlash chip (or AVR SPI controller), the other to the
- * AVR USI controller.
- */
-
 static inline void
 setsck(struct spi_device *spi, int is_on)
 {
         struct butterfly        *pp = spidev_to_pp(spi);
         u8                      bit, byte = pp->lastbyte;
 
-        if (is_usidev(spi))
-                bit = usi_sck_bit;
-        else
-                bit = spi_sck_bit;
+        bit = spi_sck_bit;
 
         if (is_on)
                 byte |= bit;
@@ -129,10 +102,7 @@ setmosi(struct spi_device *spi, int is_on)
         struct butterfly        *pp = spidev_to_pp(spi);
         u8                      bit, byte = pp->lastbyte;
 
-        if (is_usidev(spi))
-                bit = usi_mosi_bit;
-        else
-                bit = spi_mosi_bit;
+        bit = spi_mosi_bit;
 
         if (is_on)
                 byte |= bit;
@@ -148,10 +118,7 @@ static inline int getmiso(struct spi_device *spi)
         int                     value;
         u8                      bit;
 
-        if (is_usidev(spi))
-                bit = usi_miso_bit;
-        else
-                bit = spi_miso_bit;
+        bit = spi_miso_bit;
 
         /* only STATUS_BUSY is NOT negated */
         value = !(parport_read_status(pp->port) & bit);
@@ -166,10 +133,6 @@ static void butterfly_chipselect(struct spi_device *spi, int value)
         if (value != BITBANG_CS_INACTIVE)
                 setsck(spi, spi->mode & SPI_CPOL);
 
-        /* no chipselect on this USI link config */
-        if (is_usidev(spi))
-                return;
-
         /* here, value == "activate or not";
          * most PARPORT_CONTROL_* bits are negated, so we must
          * morph it to value == "bit value to write in control register"
@@ -292,7 +255,7 @@ static void butterfly_attach(struct parport *p)
         parport_frob_control(pp->port, spi_cs_bit, 0);
 
         /* stabilize power with chip in reset (nRESET), and
-         * both spi_sck_bit and usi_sck_bit clear (CPOL=0)
+         * spi_sck_bit clear (CPOL=0)
          */
         pp->lastbyte |= vcc_bits;
         parport_write_data(pp->port, pp->lastbyte);
@@ -326,23 +289,6 @@ static void butterfly_attach(struct parport *p)
                 pr_debug("%s: dataflash at %s\n", p->name,
                                 pp->dataflash->dev.bus_id);
 
-#ifdef  HAVE_USI
-        /* Bus 2 is only for talking to the AVR, and it can work no
-         * matter who masters bus 1; needs appropriate AVR firmware.
-         */
-        pp->info[1].max_speed_hz = 10 /* ?? */ * 1000 * 1000;
-        strcpy(pp->info[1].modalias, "butterfly");
-        // pp->info[1].platform_data = ... TBD ... ;
-        pp->info[1].chip_select = 2,
-        pp->info[1].controller_data = pp;
-        pp->butterfly = spi_new_device(pp->bitbang.master, &pp->info[1]);
-        if (pp->butterfly)
-                pr_debug("%s: butterfly at %s\n", p->name,
-                                pp->butterfly->dev.bus_id);
-
-        /* FIXME setup ACK for the IRQ line ...  */
-#endif
-
         // dev_info(_what?_, ...)
         pr_info("%s: AVR Butterfly\n", p->name);
         butterfly = pp;