summaryrefslogtreecommitdiff
path: root/drivers/spi
diff options
context:
space:
mode:
authorDavid Brownell <david-b@pacbell.net>2007-05-08 11:32:13 +0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-08 22:15:15 +0400
commit735ce95e6b9a262d1fbc0ddb5620deb3a29d1067 (patch)
tree37223ea350e690d1284dbcba35350767330684c7 /drivers/spi
parentfef92c30d48a9c610e35af6b218db03f770f3c65 (diff)
downloadlinux-735ce95e6b9a262d1fbc0ddb5620deb3a29d1067.tar.xz
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>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi_butterfly.c62
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;