The SPI controller found in the BCM2711 and BCM7211 SoCs is instantiated
5 times, with all instances sharing the same interrupt line. We
specifically match the two compatible strings here to determine whether
it is necessary to request the interrupt with the IRQF_SHARED flag and
to use an appropriate interrupt handler capable of returning IRQ_NONE.
For the BCM2835 case which is deemed performance critical, there is no
overhead since a dedicated handler that does not assume sharing is used.
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
drivers/spi/spi-bcm2835.c | 48 +++++++++++++++++++++++++++++++--------
1 file changed, 38 insertions(+), 10 deletions(-)
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index 237bd306c268..2e73ec70ee80 100644
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -361,11 +361,10 @@ static void bcm2835_spi_reset_hw(struct spi_controller *ctlr)
bcm2835_wr(bs, BCM2835_SPI_DLEN, 0);
}
-static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id)
+static inline irqreturn_t bcm2835_spi_interrupt_common(struct spi_controller *ctlr,
+ u32 cs)
{
- struct spi_controller *ctlr = dev_id;
struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
- u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
/*
* An interrupt is signaled either if DONE is set (TX FIFO empty)
@@ -394,6 +393,27 @@ static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
+static irqreturn_t bcm2835_spi_interrupt(int irq, void *dev_id)
+{
+ struct spi_controller *ctlr = dev_id;
+ struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
+ u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
+
+ return bcm2835_spi_interrupt_common(ctlr, cs);
+}
+
+static irqreturn_t bcm2835_spi_sh_interrupt(int irq, void *dev_id)
+{
+ struct spi_controller *ctlr = dev_id;
+ struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
+ u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
+
+ if (!(cs & BCM2835_SPI_CS_INTR))
+ return IRQ_NONE;
+
+ return bcm2835_spi_interrupt_common(ctlr, cs);
+}
+
static int bcm2835_spi_transfer_one_irq(struct spi_controller *ctlr,
struct spi_device *spi,
struct spi_transfer *tfr,
@@ -1287,12 +1307,26 @@ static int bcm2835_spi_setup(struct spi_device *spi)
return 0;
}
+static const struct of_device_id bcm2835_spi_match[] = {
+ { .compatible = "brcm,bcm2835-spi", .data = &bcm2835_spi_interrupt },
+ { .compatible = "brcm,bcm2711-spi", .data = &bcm2835_spi_sh_interrupt },
+ { .compatible = "brcm,bcm7211-spi", .data = &bcm2835_spi_sh_interrupt },
+ {}
+};
+MODULE_DEVICE_TABLE(of, bcm2835_spi_match);
+
static int bcm2835_spi_probe(struct platform_device *pdev)
{
+ irqreturn_t (*bcm2835_spi_isr_func)(int, void *);
struct spi_controller *ctlr;
+ unsigned long flags = 0;
struct bcm2835_spi *bs;
int err;
+ bcm2835_spi_isr_func = of_device_get_match_data(&pdev->dev);
+ if (bcm2835_spi_isr_func == &bcm2835_spi_sh_interrupt)
+ flags = IRQF_SHARED;
+
ctlr = spi_alloc_master(&pdev->dev, ALIGN(sizeof(*bs),
dma_get_cache_alignment()));
if (!ctlr)
@@ -1344,7 +1378,7 @@ 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_isr_func, flags,
dev_name(&pdev->dev), ctlr);
if (err) {
dev_err(&pdev->dev, "could not request IRQ: %d\n", err);
@@ -1400,12 +1434,6 @@ static void bcm2835_spi_shutdown(struct platform_device *pdev)
dev_err(&pdev->dev, "failed to shutdown\n");
}
-static const struct of_device_id bcm2835_spi_match[] = {
- { .compatible = "brcm,bcm2835-spi", },
- {}
-};
-MODULE_DEVICE_TABLE(of, bcm2835_spi_match);
-
static struct platform_driver bcm2835_spi_driver = {
.driver = {
.name = DRV_NAME,
--
2.17.1
