Fix tsx210x detection

If the return value is all 0xff, it means there's no device.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/drivers/spi/tsc210x.c b/drivers/spi/tsc210x.c
index df8bcf91bf9d1f6e8789b4b9e70897a8a2c8d2c6..1d2ac94084c477590d151a38fe96c3f2090ea56c 100644 (file)
--- a/drivers/spi/tsc210x.c
+++ b/drivers/spi/tsc210x.c
@@ -1092,6 +1092,11 @@ static int tsc210x_probe(struct spi_device *spi, enum tsc_type type)
                dev_dbg(&dev->spi->dev, "revision, err %d\n", err);
                goto err_spi;
        }
+       if (reg == 0xffff) {
+               err = -ENODEV;
+               dev_dbg(&dev->spi->dev, "no device, err %d\n", err);
+               goto err_spi;
+       }
        dev_info(&spi->dev, "rev %d, irq %d\n", reg & 0x0007, spi->irq);
 
        err = tsc210x_configure(dev);