diff options
Diffstat (limited to 'drivers/spi/spi_butterfly.c')
| -rw-r--r-- | drivers/spi/spi_butterfly.c | 36 |
1 files changed, 17 insertions, 19 deletions
diff --git a/drivers/spi/spi_butterfly.c b/drivers/spi/spi_butterfly.c index 79a3c59..ff9e5fa 100644 --- a/drivers/spi/spi_butterfly.c +++ b/drivers/spi/spi_butterfly.c @@ -163,21 +163,20 @@ static void butterfly_chipselect(struct spi_device *spi, int value) struct butterfly *pp = spidev_to_pp(spi); /* set default clock polarity */ - if (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 */ + /* 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" + */ if (spi_cs_bit == PARPORT_CONTROL_INIT) value = !value; - /* here, value == "bit value to write in control register" */ - parport_frob_control(pp->port, spi_cs_bit, value ? spi_cs_bit : 0); } @@ -202,7 +201,9 @@ butterfly_txrx_word_mode0(struct spi_device *spi, /* override default partitioning with cmdlinepart */ static struct mtd_partition partitions[] = { { - /* JFFS2 wants partitions of 4*N blocks for this device ... */ + /* JFFS2 wants partitions of 4*N blocks for this device, + * so sectors 0 and 1 can't be partitions by themselves. + */ /* sector 0 = 8 pages * 264 bytes/page (1 block) * sector 1 = 248 pages * 264 bytes/page @@ -316,8 +317,9 @@ static void butterfly_attach(struct parport *p) if (status < 0) goto clean2; - /* Bus 1 lets us talk to at45db041b (firmware disables AVR) - * or AVR (firmware resets at45, acts as spi slave) + /* Bus 1 lets us talk to at45db041b (firmware disables AVR SPI), AVR + * (firmware resets at45, acts as spi slave) or neither (we ignore + * both, AVR uses AT45). Here we expect firmware for the first option. */ pp->info[0].max_speed_hz = 15 * 1000 * 1000; strcpy(pp->info[0].modalias, "mtd_dataflash"); @@ -330,7 +332,9 @@ static void butterfly_attach(struct parport *p) pp->dataflash->dev.bus_id); #ifdef HAVE_USI - /* even more custom AVR firmware */ + /* 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 ... ; @@ -378,13 +382,8 @@ static void butterfly_detach(struct parport *p) pp = butterfly; butterfly = NULL; -#ifdef HAVE_USI - spi_unregister_device(pp->butterfly); - pp->butterfly = NULL; -#endif - spi_unregister_device(pp->dataflash); - pp->dataflash = NULL; - + /* stop() unregisters child devices too */ + pdev = to_platform_device(pp->bitbang.master->cdev.dev); status = spi_bitbang_stop(&pp->bitbang); /* turn off VCC */ @@ -394,8 +393,6 @@ static void butterfly_detach(struct parport *p) parport_release(pp->pd); parport_unregister_device(pp->pd); - pdev = to_platform_device(pp->bitbang.master->cdev.dev); - (void) spi_master_put(pp->bitbang.master); platform_device_unregister(pdev); @@ -420,4 +417,5 @@ static void __exit butterfly_exit(void) } module_exit(butterfly_exit); +MODULE_DESCRIPTION("Parport Adapter driver for AVR Butterfly"); MODULE_LICENSE("GPL"); |