From 375981f2e14868be16cafbffd34a4f16a6ee01c6 Mon Sep 17 00:00:00 2001 From: Girish K S Date: Wed, 13 Mar 2013 12:13:30 +0530 Subject: spi/s3c64xx: modified error interrupt handling and init The status of the interrupt is available in the status register, so reading the clear pending register and writing back the same value will not actually clear the pending interrupts. This patch modifies the interrupt handler to read the status register and clear the corresponding pending bit in the clear pending register. Modified the hwInit function to clear all the pending interrupts. Signed-off-by: Girish K S Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/spi/spi-s3c64xx.c | 41 +++++++++++++++++++++++++---------------- 1 file changed, 25 insertions(+), 16 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index e862ab8853aa..4188b2faac5c 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -994,25 +994,30 @@ static irqreturn_t s3c64xx_spi_irq(int irq, void *data) { struct s3c64xx_spi_driver_data *sdd = data; struct spi_master *spi = sdd->master; - unsigned int val; + unsigned int val, clr = 0; - val = readl(sdd->regs + S3C64XX_SPI_PENDING_CLR); + val = readl(sdd->regs + S3C64XX_SPI_STATUS); - val &= S3C64XX_SPI_PND_RX_OVERRUN_CLR | - S3C64XX_SPI_PND_RX_UNDERRUN_CLR | - S3C64XX_SPI_PND_TX_OVERRUN_CLR | - S3C64XX_SPI_PND_TX_UNDERRUN_CLR; - - writel(val, sdd->regs + S3C64XX_SPI_PENDING_CLR); - - if (val & S3C64XX_SPI_PND_RX_OVERRUN_CLR) + if (val & S3C64XX_SPI_ST_RX_OVERRUN_ERR) { + clr = S3C64XX_SPI_PND_RX_OVERRUN_CLR; dev_err(&spi->dev, "RX overrun\n"); - if (val & S3C64XX_SPI_PND_RX_UNDERRUN_CLR) + } + if (val & S3C64XX_SPI_ST_RX_UNDERRUN_ERR) { + clr |= S3C64XX_SPI_PND_RX_UNDERRUN_CLR; dev_err(&spi->dev, "RX underrun\n"); - if (val & S3C64XX_SPI_PND_TX_OVERRUN_CLR) + } + if (val & S3C64XX_SPI_ST_TX_OVERRUN_ERR) { + clr |= S3C64XX_SPI_PND_TX_OVERRUN_CLR; dev_err(&spi->dev, "TX overrun\n"); - if (val & S3C64XX_SPI_PND_TX_UNDERRUN_CLR) + } + if (val & S3C64XX_SPI_ST_TX_UNDERRUN_ERR) { + clr |= S3C64XX_SPI_PND_TX_UNDERRUN_CLR; dev_err(&spi->dev, "TX underrun\n"); + } + + /* Clear the pending irq by setting and then clearing it */ + writel(clr, sdd->regs + S3C64XX_SPI_PENDING_CLR); + writel(0, sdd->regs + S3C64XX_SPI_PENDING_CLR); return IRQ_HANDLED; } @@ -1036,9 +1041,13 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd, int channel) writel(0, regs + S3C64XX_SPI_MODE_CFG); writel(0, regs + S3C64XX_SPI_PACKET_CNT); - /* Clear any irq pending bits */ - writel(readl(regs + S3C64XX_SPI_PENDING_CLR), - regs + S3C64XX_SPI_PENDING_CLR); + /* Clear any irq pending bits, should set and clear the bits */ + val = S3C64XX_SPI_PND_RX_OVERRUN_CLR | + S3C64XX_SPI_PND_RX_UNDERRUN_CLR | + S3C64XX_SPI_PND_TX_OVERRUN_CLR | + S3C64XX_SPI_PND_TX_UNDERRUN_CLR; + writel(val, regs + S3C64XX_SPI_PENDING_CLR); + writel(0, regs + S3C64XX_SPI_PENDING_CLR); writel(0, regs + S3C64XX_SPI_SWAP_CFG); -- cgit v1.2.3-59-g8ed1b From b0b36b861e434ee1c1a64cb39259e262f79af62e Mon Sep 17 00:00:00 2001 From: Bryan Freed Date: Wed, 13 Mar 2013 11:17:40 -0700 Subject: spi: Unlock a spinlock before calling into the controller driver. spi_pump_messages() calls into a controller driver with unprepare_transfer_hardware() which is documented as "This may sleep". As in the prepare_transfer_hardware() call below, we should release the queue_lock spinlock before making the call. Rework the logic a bit to hold queue_lock to protect the 'busy' flag, then release it to call unprepare_transfer_hardware(). Signed-off-by: Bryan Freed Reviewed-by: Doug Anderson Signed-off-by: Doug Anderson Acked-by: Linus Walleij Signed-off-by: Mark Brown --- drivers/spi/spi.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index f996c600eb8c..5b96250b0628 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -543,17 +543,16 @@ static void spi_pump_messages(struct kthread_work *work) /* Lock queue and check for queue work */ spin_lock_irqsave(&master->queue_lock, flags); if (list_empty(&master->queue) || !master->running) { - if (master->busy && master->unprepare_transfer_hardware) { - ret = master->unprepare_transfer_hardware(master); - if (ret) { - spin_unlock_irqrestore(&master->queue_lock, flags); - dev_err(&master->dev, - "failed to unprepare transfer hardware\n"); - return; - } + if (!master->busy) { + spin_unlock_irqrestore(&master->queue_lock, flags); + return; } master->busy = false; spin_unlock_irqrestore(&master->queue_lock, flags); + if (master->unprepare_transfer_hardware && + master->unprepare_transfer_hardware(master)) + dev_err(&master->dev, + "failed to unprepare transfer hardware\n"); return; } -- cgit v1.2.3-59-g8ed1b From 1ad849aee5f53353ed88d9cd3d68a51b03a7d44f Mon Sep 17 00:00:00 2001 From: Anatolij Gustschin Date: Wed, 13 Mar 2013 14:57:43 +0100 Subject: spi/mpc512x-psc: optionally keep PSC SS asserted across xfer segmensts Some SPI slave devices require asserted chip select signal across multiple transfer segments of an SPI message. Currently the driver always de-asserts the internal SS signal for every single transfer segment of the message and ignores the 'cs_change' flag of the transfer description. Disable the internal chip select (SS) only if this is needed and indicated by the 'cs_change' flag. Without this change, each partial transfer of a surrounding multi-part SPI transaction might erroneously change the SS signal, which might prevent slaves from answering the request that was sent in a previous transfer segment because the transaction could be considered aborted (SS was de-asserted before reading the response). Reported-by: Gerhard Sittig Signed-off-by: Anatolij Gustschin Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/spi/spi-mpc512x-psc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c index 89480b281d74..3e490ee7f275 100644 --- a/drivers/spi/spi-mpc512x-psc.c +++ b/drivers/spi/spi-mpc512x-psc.c @@ -164,7 +164,7 @@ static int mpc512x_psc_spi_transfer_rxtx(struct spi_device *spi, for (i = count; i > 0; i--) { data = tx_buf ? *tx_buf++ : 0; - if (len == EOFBYTE) + if (len == EOFBYTE && t->cs_change) setbits32(&fifo->txcmd, MPC512x_PSC_FIFO_EOF); out_8(&fifo->txdata_8, data); len--; -- cgit v1.2.3-59-g8ed1b