diff options
Diffstat (limited to 'drivers/serial/mrst_max3110.c')
| -rw-r--r-- | drivers/serial/mrst_max3110.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/serial/mrst_max3110.c b/drivers/serial/mrst_max3110.c index 273e7cbe74c..f9c01aeb6f8 100644 --- a/drivers/serial/mrst_max3110.c +++ b/drivers/serial/mrst_max3110.c @@ -721,7 +721,7 @@ static int serial_m3110_probe(struct spi_device *spi) struct uart_max3110 *max; int ret; unsigned char *buffer; - + u16 res; max = kzalloc(sizeof(*max), GFP_KERNEL); if (!max) return -ENOMEM; @@ -753,7 +753,16 @@ static int serial_m3110_probe(struct spi_device *spi) max->cur_conf = 0; atomic_set(&max->irq_pending, 0); - + /* Check if reading configuration register returns something sane */ + + res = RC_TAG; + ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0); + if (ret < 0 || res == 0 || res == 0xffff) { + printk(KERN_ERR "MAX3111 deemed not present (conf reg %04x)", + res); + ret = -ENODEV; + goto err_get_page; + } buffer = (unsigned char *)__get_free_page(GFP_KERNEL); if (!buffer) { ret = -ENOMEM; |