From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 1/2] spi/bfin_spi: support for multiples of 8bits with hardware CS Date: Tue, 15 Feb 2011 15:06:18 -0700 Message-ID: <20110215220618.GC28005@angua.secretlab.ca> References: <1294762748-25122-1-git-send-email-vapier@gentoo.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Bob Liu , David Brownell , uclinux-dist-devel-ZG0+EudsQA8dtHy/vicBwGD2FQJk+8+b@public.gmane.org To: Mike Frysinger Return-path: Content-Disposition: inline In-Reply-To: <1294762748-25122-1-git-send-email-vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Tue, Jan 11, 2011 at 11:19:07AM -0500, Mike Frysinger wrote: > From: Bob Liu > > We can do multiples of 8bit transfers when using the hardware CS and a > little bit of magic, so make it work. > > Signed-off-by: Bob Liu > Signed-off-by: Mike Frysinger Applied, thanks g. > --- > drivers/spi/spi_bfin5xx.c | 103 +++++++++++++++++++++++++++++++-------------- > 1 files changed, 71 insertions(+), 32 deletions(-) > > diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c > index 3f22351..e8d68b7 100644 > --- a/drivers/spi/spi_bfin5xx.c > +++ b/drivers/spi/spi_bfin5xx.c > @@ -425,6 +425,7 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id) > struct bfin_spi_slave_data *chip = drv_data->cur_chip; > struct spi_message *msg = drv_data->cur_msg; > int n_bytes = drv_data->n_bytes; > + int loop = 0; > > /* wait until transfer finished. */ > while (!(read_STAT(drv_data) & BIT_STAT_RXS)) > @@ -435,10 +436,15 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id) > /* last read */ > if (drv_data->rx) { > dev_dbg(&drv_data->pdev->dev, "last read\n"); > - if (n_bytes == 2) > - *(u16 *) (drv_data->rx) = read_RDBR(drv_data); > - else if (n_bytes == 1) > - *(u8 *) (drv_data->rx) = read_RDBR(drv_data); > + if (n_bytes % 2) { > + u16 *buf = (u16 *)drv_data->rx; > + for (loop = 0; loop < n_bytes / 2; loop++) > + *buf++ = read_RDBR(drv_data); > + } else { > + u8 *buf = (u8 *)drv_data->rx; > + for (loop = 0; loop < n_bytes; loop++) > + *buf++ = read_RDBR(drv_data); > + } > drv_data->rx += n_bytes; > } > > @@ -458,29 +464,53 @@ static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id) > if (drv_data->rx && drv_data->tx) { > /* duplex */ > dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n"); > - if (drv_data->n_bytes == 2) { > - *(u16 *) (drv_data->rx) = read_RDBR(drv_data); > - write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); > - } else if (drv_data->n_bytes == 1) { > - *(u8 *) (drv_data->rx) = read_RDBR(drv_data); > - write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); > + if (n_bytes % 2) { > + u16 *buf = (u16 *)drv_data->rx; > + u16 *buf2 = (u16 *)drv_data->tx; > + for (loop = 0; loop < n_bytes / 2; loop++) { > + *buf++ = read_RDBR(drv_data); > + write_TDBR(drv_data, *buf2++); > + } > + } else { > + u8 *buf = (u8 *)drv_data->rx; > + u8 *buf2 = (u8 *)drv_data->tx; > + for (loop = 0; loop < n_bytes; loop++) { > + *buf++ = read_RDBR(drv_data); > + write_TDBR(drv_data, *buf2++); > + } > } > } else if (drv_data->rx) { > /* read */ > dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n"); > - if (drv_data->n_bytes == 2) > - *(u16 *) (drv_data->rx) = read_RDBR(drv_data); > - else if (drv_data->n_bytes == 1) > - *(u8 *) (drv_data->rx) = read_RDBR(drv_data); > - write_TDBR(drv_data, chip->idle_tx_val); > + if (n_bytes % 2) { > + u16 *buf = (u16 *)drv_data->rx; > + for (loop = 0; loop < n_bytes / 2; loop++) { > + *buf++ = read_RDBR(drv_data); > + write_TDBR(drv_data, chip->idle_tx_val); > + } > + } else { > + u8 *buf = (u8 *)drv_data->rx; > + for (loop = 0; loop < n_bytes; loop++) { > + *buf++ = read_RDBR(drv_data); > + write_TDBR(drv_data, chip->idle_tx_val); > + } > + } > } else if (drv_data->tx) { > /* write */ > dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n"); > - bfin_spi_dummy_read(drv_data); > - if (drv_data->n_bytes == 2) > - write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); > - else if (drv_data->n_bytes == 1) > - write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); > + if (n_bytes % 2) { > + u16 *buf = (u16 *)drv_data->tx; > + for (loop = 0; loop < n_bytes / 2; loop++) { > + read_RDBR(drv_data); > + write_TDBR(drv_data, *buf++); > + } > + } else { > + u8 *buf = (u8 *)drv_data->tx; > + for (loop = 0; loop < n_bytes; loop++) { > + read_RDBR(drv_data); > + write_TDBR(drv_data, *buf++); > + } > + } > } > > if (drv_data->tx) > @@ -651,16 +681,16 @@ static void bfin_spi_pump_transfers(unsigned long data) > > /* Bits per word setup */ > bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word; > - if (bits_per_word == 8) { > - drv_data->n_bytes = 1; > - drv_data->len = transfer->len; > - cr_width = 0; > - drv_data->ops = &bfin_bfin_spi_transfer_ops_u8; > - } else if (bits_per_word == 16) { > - drv_data->n_bytes = 2; > + if ((bits_per_word > 0) && (bits_per_word % 16 == 0)) { > + drv_data->n_bytes = bits_per_word/8; > drv_data->len = (transfer->len) >> 1; > cr_width = BIT_CTL_WORDSIZE; > drv_data->ops = &bfin_bfin_spi_transfer_ops_u16; > + } else if ((bits_per_word > 0) && (bits_per_word % 8 == 0)) { > + drv_data->n_bytes = bits_per_word/8; > + drv_data->len = transfer->len; > + cr_width = 0; > + drv_data->ops = &bfin_bfin_spi_transfer_ops_u8; > } else { > dev_err(&drv_data->pdev->dev, "transfer: unsupported bits_per_word\n"); > message->status = -EINVAL; > @@ -815,10 +845,19 @@ static void bfin_spi_pump_transfers(unsigned long data) > if (drv_data->tx == NULL) > write_TDBR(drv_data, chip->idle_tx_val); > else { > - if (bits_per_word == 8) > - write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); > - else > - write_TDBR(drv_data, (*(u16 *) (drv_data->tx))); > + int loop; > + if (bits_per_word % 16 == 0) { > + u16 *buf = (u16 *)drv_data->tx; > + for (loop = 0; loop < bits_per_word / 16; > + loop++) { > + write_TDBR(drv_data, *buf++); > + } > + } else if (bits_per_word % 8 == 0) { > + u8 *buf = (u8 *)drv_data->tx; > + for (loop = 0; loop < bits_per_word / 8; loop++) > + write_TDBR(drv_data, *buf++); > + } > + > drv_data->tx += drv_data->n_bytes; > } > > @@ -1031,7 +1070,7 @@ static int bfin_spi_setup(struct spi_device *spi) > chip->ctl_reg &= bfin_ctl_reg; > } > > - if (spi->bits_per_word != 8 && spi->bits_per_word != 16) { > + if (spi->bits_per_word % 8) { > dev_err(&spi->dev, "%d bits_per_word is not supported\n", > spi->bits_per_word); > goto error; > -- > 1.7.4.rc1 > ------------------------------------------------------------------------------ The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE: Pinpoint memory and threading errors before they happen. Find and fix more than 250 security defects in the development cycle. Locate bottlenecks in serial and parallel code that limit performance. http://p.sf.net/sfu/intel-dev2devfeb