mtd: nand: pxa3xx: Support command buffer #3
Some newer controllers support a fourth command buffer. This additional
command buffer allows to set an arbitrary length count, using the
NDCB3.NDLENCNT field, to perform non-standard length operations
such as the ONFI parameter page read.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 6e28121..b3fc146 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -197,6 +197,7 @@
uint32_t ndcb0;
uint32_t ndcb1;
uint32_t ndcb2;
+ uint32_t ndcb3;
};
static bool use_dma = 1;
@@ -493,9 +494,22 @@
nand_writel(info, NDSR, NDSR_WRCMDREQ);
status &= ~NDSR_WRCMDREQ;
info->state = STATE_CMD_HANDLE;
+
+ /*
+ * Command buffer registers NDCB{0-2} (and optionally NDCB3)
+ * must be loaded by writing directly either 12 or 16
+ * bytes directly to NDCB0, four bytes at a time.
+ *
+ * Direct write access to NDCB1, NDCB2 and NDCB3 is ignored
+ * but each NDCBx register can be read.
+ */
nand_writel(info, NDCB0, info->ndcb0);
nand_writel(info, NDCB0, info->ndcb1);
nand_writel(info, NDCB0, info->ndcb2);
+
+ /* NDCB3 register is available in NFCv2 (Armada 370/XP SoC) */
+ if (info->variant == PXA3XX_NAND_VARIANT_ARMADA370)
+ nand_writel(info, NDCB0, info->ndcb3);
}
/* clear NDSR to let the controller exit the IRQ */
@@ -554,6 +568,7 @@
default:
info->ndcb1 = 0;
info->ndcb2 = 0;
+ info->ndcb3 = 0;
break;
}