[PATCH 4.4 18/23] spi: bcm2835aux: unifying code between polling and interrupt driven code

Greg Kroah-Hartman
2019-09-08T12:43:41Z

[ Upstream commit 7188a6f0eee3f1fae5d826cfc6d569657ff950ec ]

Sharing more code between polling and interrupt-driven mode.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-bcm2835aux.c | 51 +++++++++++++-----------------------
1 file changed, 18 insertions(+), 33 deletions(-)

diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index 6f4c6aa801f14..5b2c2b2e13396 100644
--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -181,23 +181,13 @@ static void bcm2835aux_spi_reset_hw(struct bcm2835aux_spi *bs)
BCM2835_AUX_SPI_CNTL0_CLEARFIFO);
}

-static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id)
+static void bcm2835aux_spi_transfer_helper(struct bcm2835aux_spi *bs)
{
- struct spi_master *master = dev_id;
- struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
- irqreturn_t ret = IRQ_NONE;
-
- /* IRQ may be shared, so return if our interrupts are disabled */
- if (!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_CNTL1) &
- (BCM2835_AUX_SPI_CNTL1_TXEMPTY | BCM2835_AUX_SPI_CNTL1_IDLE)))
- return ret;
-
/* check if we have data to read */
while (bs->rx_len &&
(!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT) &
BCM2835_AUX_SPI_STAT_RX_EMPTY))) {
bcm2835aux_rd_fifo(bs);
- ret = IRQ_HANDLED;
}

/* check if we have data to write */
@@ -206,7 +196,6 @@ static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id)
(!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT) &
BCM2835_AUX_SPI_STAT_TX_FULL))) {
bcm2835aux_wr_fifo(bs);
- ret = IRQ_HANDLED;
}

/* and check if we have reached "done" */
@@ -214,8 +203,21 @@ static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id)
(!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT) &
BCM2835_AUX_SPI_STAT_BUSY))) {
bcm2835aux_rd_fifo(bs);
- ret = IRQ_HANDLED;
}
+}
+
+static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id)
+{
+ struct spi_master *master = dev_id;
+ struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
+
+ /* IRQ may be shared, so return if our interrupts are disabled */
+ if (!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_CNTL1) &
+ (BCM2835_AUX_SPI_CNTL1_TXEMPTY | BCM2835_AUX_SPI_CNTL1_IDLE)))
+ return IRQ_NONE;
+
+ /* do common fifo handling */
+ bcm2835aux_spi_transfer_helper(bs);

/* and if rx_len is 0 then wake up completion and disable spi */
if (!bs->rx_len) {
@@ -223,8 +225,7 @@ static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id)
complete(&master->xfer_completion);
}

- /* and return */
- return ret;
+ return IRQ_HANDLED;
}

static int __bcm2835aux_spi_transfer_one_irq(struct spi_master *master,
@@ -270,7 +271,6 @@ static int bcm2835aux_spi_transfer_one_poll(struct spi_master *master,
{
struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
unsigned long timeout;
- u32 stat;

/* configure spi */
bcm2835aux_wr(bs, BCM2835_AUX_SPI_CNTL1, bs->cntl[1]);
@@ -281,24 +281,9 @@ static int bcm2835aux_spi_transfer_one_poll(struct spi_master *master,

/* loop until finished the transfer */
while (bs->rx_len) {
- /* read status */
- stat = bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT);
-
- /* fill in tx fifo with remaining data */
- if ((bs->tx_len) && (!(stat & BCM2835_AUX_SPI_STAT_TX_FULL))) {
- bcm2835aux_wr_fifo(bs);
- continue;
- }

- /* read data from fifo for both cases */
- if (!(stat & BCM2835_AUX_SPI_STAT_RX_EMPTY)) {
- bcm2835aux_rd_fifo(bs);
- continue;
- }
- if (!(stat & BCM2835_AUX_SPI_STAT_BUSY)) {
- bcm2835aux_rd_fifo(bs);
- continue;
- }
+ /* do common fifo handling */
+ bcm2835aux_spi_transfer_helper(bs);

/* there is still data pending to read check the timeout */
if (bs->rx_len && time_after(jiffies, timeout)) {
--
2.20.1