mtd: nand: raw: atmel: Add error handling when rb-gpios missing

Adapt behaviour to Linux kernel driver.

The return value of gpio_request_by_name_nodev() was not checked before,
and thus in case 'rb-gpios' was missing in DT, rb.type was set to
ATMEL_NAND_GPIO_RB nevertheless, leading to output like this for
example (on sam9x60-curiosity with the line removed from dts):

    NAND:  Could not find valid ONFI parameter page; aborting
    device found, Manufacturer ID: 0xc2, Chip ID: 0xdc
    Macronix NAND 512MiB 3,3V 8-bit
    512 MiB, SLC, erase size: 256 KiB, page size: 4096, OOB size: 64
    atmel-nand-controller nand-controller: NAND scan failed: -22
    Failed to probe nand driver (err = -22)
    Failed to initialize NAND controller. (error -22)
    0 MiB

Note: not having that gpio assigned in dts is possible, the driver does
not override nand_chip->dev_ready() then and a generic solution is used.

Fixes: 6a8dfd57220d ("nand: atmel: Add DM based NAND driver")
Signed-off-by: Alexander Dahl <ada@thorsis.com>
Reviewed-by: Eugen Hristev <eugen.hristev@collabora.com>
Acked-by: Michael Trimarchi <michael@amarulasolutions.com>

diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
index 9873d11..950e626 100644 (file)
--- a/drivers/mtd/nand/raw/atmel/nand-controller.c
+++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
@@ -1601,10 +1601,13 @@ static struct atmel_nand *atmel_nand_create(struct atmel_nand_controller *nc,
                        nand->cs[i].rb.type = ATMEL_NAND_NATIVE_RB;
                        nand->cs[i].rb.id = val;
                } else {
-                       gpio_request_by_name_nodev(np, "rb-gpios", 0,
-                                                  &nand->cs[i].rb.gpio,
-                                                  GPIOD_IS_IN);
-                       nand->cs[i].rb.type = ATMEL_NAND_GPIO_RB;
+                       ret = gpio_request_by_name_nodev(np, "rb-gpios", 0,
+                                                        &nand->cs[i].rb.gpio,
+                                                        GPIOD_IS_IN);
+                       if (ret && ret != -ENOENT)
+                               dev_err(nc->dev, "Failed to get R/B gpio (err = %d)\n", ret);
+                       if (!ret)
+                               nand->cs[i].rb.type = ATMEL_NAND_GPIO_RB;
                }
 
                gpio_request_by_name_nodev(np, "cs-gpios", 0,