spi: bcm2835aux: unifying code between polling and interrupt driven code

BugLink: https://bugs.launchpad.net/bugs/1845374

[ Upstream commit 7188a6f0 ]

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>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

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)) {