spi/pxa2xx: add support for shared IRQ handler

This is required in case the interrupt line is shared with other
devices.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
index 4e169b579efb..1865c23f2175 100644
--- a/drivers/spi/pxa2xx_spi.c
+++ b/drivers/spi/pxa2xx_spi.c
@@ -742,6 +742,18 @@ static irqreturn_t ssp_int(int irq, void *dev_id)
 {
         struct driver_data *drv_data = dev_id;
         void __iomem *reg = drv_data->ioaddr;
+        u32 sccr1_reg = read_SSCR1(reg);
+        u32 mask = drv_data->mask_sr;
+        u32 status;
+
+        status = read_SSSR(reg);
+
+        /* Ignore possible writes if we don't need to write */
+        if (!(sccr1_reg & SSCR1_TIE))
+                mask &= ~SSSR_TFS;
+
+        if (!(status & mask))
+                return IRQ_NONE;
 
         if (!drv_data->cur_msg) {
 
@@ -1512,7 +1524,8 @@ static int __devinit pxa2xx_spi_probe(struct platform_device *pdev)
                 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
         }
 
-        status = request_irq(ssp->irq, ssp_int, 0, dev_name(dev), drv_data);
+        status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
+                        drv_data);
         if (status < 0) {
                 dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
                 goto out_error_master_alloc;