From ecfbd3cf3b8bb73ac6a80ddf430b5912fd4402a6 Mon Sep 17 00:00:00 2001 From: Martin Sperl Date: Thu, 28 May 2020 20:58:04 +0200 Subject: [PATCH] spi: bcm2835: Enable shared interrupt support bcm2711, Rasberry Pi 4's SoC, shares one interrupt for multiple instances of the bcm2835 SPI controller. So this enables shared interrupt support for them. The early bail out in the interrupt routine avoids messing with buffers of transfers being done by other means. Otherwise, the driver can handle receiving interrupts asserted by other controllers during an IRQ based transfer. Signed-off-by: Martin Sperl Signed-off-by: Nicolas Saenz Julienne Tested-by: Florian Fainelli Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/20200528185805.28991-1-nsaenzjulienne@suse.de Signed-off-by: Mark Brown --- drivers/spi/spi-bcm2835.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 237bd306c268..f3e41676e825 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -379,6 +379,10 @@ 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 */ @@ -1344,8 +1348,8 @@ 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, - dev_name(&pdev->dev), ctlr); + err = devm_request_irq(&pdev->dev, bs->irq, bcm2835_spi_interrupt, + IRQF_SHARED, dev_name(&pdev->dev), ctlr); if (err) { dev_err(&pdev->dev, "could not request IRQ: %d\n", err); goto out_dma_release;