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minor spi_butterfly cleanup

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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>
This commit is contained in:
David Brownell 2007-05-08 00:32:13 -07:00 committed by Linus Torvalds
parent fef92c30d4
commit 735ce95e6b
1 changed files with 4 additions and 58 deletions
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62
drivers/spi/spi_butterfly.c
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@ -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;