X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fspi%2Fspi-bitbang.c;fp=kernel%2Fdrivers%2Fspi%2Fspi-bitbang.c;h=3aa9e6e3dac82d63f1abf58e5b7eb4aacbb8f212;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=840a4984d3650e27dcf98713235a67e040b8ca1a;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git diff --git a/kernel/drivers/spi/spi-bitbang.c b/kernel/drivers/spi/spi-bitbang.c index 840a4984d..3aa9e6e3d 100644 --- a/kernel/drivers/spi/spi-bitbang.c +++ b/kernel/drivers/spi/spi-bitbang.c @@ -24,6 +24,8 @@ #include #include +#define SPI_BITBANG_CS_DELAY 100 + /*----------------------------------------------------------------------*/ @@ -180,7 +182,6 @@ int spi_bitbang_setup(struct spi_device *spi) { struct spi_bitbang_cs *cs = spi->controller_state; struct spi_bitbang *bitbang; - unsigned long flags; bitbang = spi_master_get_devdata(spi->master); @@ -210,12 +211,12 @@ int spi_bitbang_setup(struct spi_device *spi) */ /* deselect chip (low or high) */ - spin_lock_irqsave(&bitbang->lock, flags); + mutex_lock(&bitbang->lock); if (!bitbang->busy) { bitbang->chipselect(spi, BITBANG_CS_INACTIVE); ndelay(cs->nsecs); } - spin_unlock_irqrestore(&bitbang->lock, flags); + mutex_unlock(&bitbang->lock); return 0; } @@ -255,122 +256,39 @@ static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t) static int spi_bitbang_prepare_hardware(struct spi_master *spi) { struct spi_bitbang *bitbang; - unsigned long flags; bitbang = spi_master_get_devdata(spi); - spin_lock_irqsave(&bitbang->lock, flags); + mutex_lock(&bitbang->lock); bitbang->busy = 1; - spin_unlock_irqrestore(&bitbang->lock, flags); + mutex_unlock(&bitbang->lock); return 0; } static int spi_bitbang_transfer_one(struct spi_master *master, - struct spi_message *m) + struct spi_device *spi, + struct spi_transfer *transfer) { - struct spi_bitbang *bitbang; - unsigned nsecs; - struct spi_transfer *t = NULL; - unsigned cs_change; - int status; - int do_setup = -1; - struct spi_device *spi = m->spi; - - bitbang = spi_master_get_devdata(master); - - /* FIXME this is made-up ... the correct value is known to - * word-at-a-time bitbang code, and presumably chipselect() - * should enforce these requirements too? - */ - nsecs = 100; - - cs_change = 1; - status = 0; - - list_for_each_entry(t, &m->transfers, transfer_list) { - - /* override speed or wordsize? */ - if (t->speed_hz || t->bits_per_word) - do_setup = 1; - - /* init (-1) or override (1) transfer params */ - if (do_setup != 0) { - if (bitbang->setup_transfer) { - status = bitbang->setup_transfer(spi, t); - if (status < 0) - break; - } - if (do_setup == -1) - do_setup = 0; - } - - /* set up default clock polarity, and activate chip; - * this implicitly updates clock and spi modes as - * previously recorded for this device via setup(). - * (and also deselects any other chip that might be - * selected ...) - */ - if (cs_change) { - bitbang->chipselect(spi, BITBANG_CS_ACTIVE); - ndelay(nsecs); - } - cs_change = t->cs_change; - if (!t->tx_buf && !t->rx_buf && t->len) { - status = -EINVAL; - break; - } - - /* transfer data. the lower level code handles any - * new dma mappings it needs. our caller always gave - * us dma-safe buffers. - */ - if (t->len) { - /* REVISIT dma API still needs a designated - * DMA_ADDR_INVALID; ~0 might be better. - */ - if (!m->is_dma_mapped) - t->rx_dma = t->tx_dma = 0; - status = bitbang->txrx_bufs(spi, t); - } - if (status > 0) - m->actual_length += status; - if (status != t->len) { - /* always report some kind of error */ - if (status >= 0) - status = -EREMOTEIO; - break; - } - status = 0; + struct spi_bitbang *bitbang = spi_master_get_devdata(master); + int status = 0; - /* protocol tweaks before next transfer */ - if (t->delay_usecs) - udelay(t->delay_usecs); - - if (cs_change && - !list_is_last(&t->transfer_list, &m->transfers)) { - /* sometimes a short mid-message deselect of the chip - * may be needed to terminate a mode or command - */ - ndelay(nsecs); - bitbang->chipselect(spi, BITBANG_CS_INACTIVE); - ndelay(nsecs); - } + if (bitbang->setup_transfer) { + status = bitbang->setup_transfer(spi, transfer); + if (status < 0) + goto out; } - m->status = status; + if (transfer->len) + status = bitbang->txrx_bufs(spi, transfer); - /* normally deactivate chipselect ... unless no error and - * cs_change has hinted that the next message will probably - * be for this chip too. - */ - if (!(status == 0 && cs_change)) { - ndelay(nsecs); - bitbang->chipselect(spi, BITBANG_CS_INACTIVE); - ndelay(nsecs); - } + if (status == transfer->len) + status = 0; + else if (status >= 0) + status = -EREMOTEIO; - spi_finalize_current_message(master); +out: + spi_finalize_current_transfer(master); return status; } @@ -378,17 +296,32 @@ static int spi_bitbang_transfer_one(struct spi_master *master, static int spi_bitbang_unprepare_hardware(struct spi_master *spi) { struct spi_bitbang *bitbang; - unsigned long flags; bitbang = spi_master_get_devdata(spi); - spin_lock_irqsave(&bitbang->lock, flags); + mutex_lock(&bitbang->lock); bitbang->busy = 0; - spin_unlock_irqrestore(&bitbang->lock, flags); + mutex_unlock(&bitbang->lock); return 0; } +static void spi_bitbang_set_cs(struct spi_device *spi, bool enable) +{ + struct spi_bitbang *bitbang = spi_master_get_devdata(spi->master); + + /* SPI core provides CS high / low, but bitbang driver + * expects CS active + * spi device driver takes care of handling SPI_CS_HIGH + */ + enable = (!!(spi->mode & SPI_CS_HIGH) == enable); + + ndelay(SPI_BITBANG_CS_DELAY); + bitbang->chipselect(spi, enable ? BITBANG_CS_ACTIVE : + BITBANG_CS_INACTIVE); + ndelay(SPI_BITBANG_CS_DELAY); +} + /*----------------------------------------------------------------------*/ /** @@ -427,7 +360,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) if (!master || !bitbang->chipselect) return -EINVAL; - spin_lock_init(&bitbang->lock); + mutex_init(&bitbang->lock); if (!master->mode_bits) master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags; @@ -437,7 +370,8 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) master->prepare_transfer_hardware = spi_bitbang_prepare_hardware; master->unprepare_transfer_hardware = spi_bitbang_unprepare_hardware; - master->transfer_one_message = spi_bitbang_transfer_one; + master->transfer_one = spi_bitbang_transfer_one; + master->set_cs = spi_bitbang_set_cs; if (!bitbang->txrx_bufs) { bitbang->use_dma = 0;