mtd: nand: Wait tCCS after a column change

Drivers implementing ->cmd_ctrl() and relying on the default ->cmdfunc()
implementation usually don't wait tCCS when a column change (RNDIN or
RNDOUT) is requested.
Add an option flag to ask the core to do so (note that we keep this as
an opt-in to avoid breaking existing implementations), and make use of
the ->data_interface information is available (otherwise, wait 500ns).

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 6fe83bce83a6..970ceb948835 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -210,6 +210,16 @@ enum nand_ecc_algo {
  */
 #define NAND_USE_BOUNCE_BUFFER  0x00100000
 
+/*
+ * In case your controller is implementing ->cmd_ctrl() and is relying on the
+ * default ->cmdfunc() implementation, you may want to let the core handle the
+ * tCCS delay which is required when a column change (RNDIN or RNDOUT) is
+ * requested.
+ * If your controller already takes care of this delay, you don't need to set
+ * this flag.
+ */
+#define NAND_WAIT_TCCS          0x00200000
+
 /* Options set by nand scan */
 /* Nand scan has allocated controller struct */
 #define NAND_CONTROLLER_ALLOC   0x80000000