spi: bcm2835: enable shared interrupt support

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

Add shared interrupt support for this driver.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/spi/spi-bcm2835.c

@@ -377,6 +377,10 @@ static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id)
 	if (bs->tx_len && cs & BCM2835_SPI_CS_DONE)
 		bcm2835_wr_fifo_blind(bs, BCM2835_SPI_FIFO_SIZE);
 
+	/* check if we got interrupt enabled */
+	if (!(bcm2835_rd(bs, BCM2835_SPI_CS) & BCM2835_SPI_CS_INTR))
+		return IRQ_NONE;
+
 	/* Read as many bytes as possible from FIFO */
 	bcm2835_rd_fifo(bs);
 	/* Write as many bytes as possible to FIFO */
@@ -1321,7 +1325,8 @@ static int bcm2835_spi_probe(struct platform_device *pdev)
 	bcm2835_wr(bs, BCM2835_SPI_CS,
 		   BCM2835_SPI_CS_CLEAR_RX | BCM2835_SPI_CS_CLEAR_TX);
 
-	err = devm_request_irq(&pdev->dev, bs->irq, bcm2835_spi_interrupt, 0,
+	err = devm_request_irq(&pdev->dev, bs->irq, bcm2835_spi_interrupt,
+			       IRQF_SHARED,
 			       dev_name(&pdev->dev), bs);
 	if (err) {
 		dev_err(&pdev->dev, "could not request IRQ: %d\n", err);