OMAP devices support various NAND transfer modes.
Currently all device-tree definitions will use the default "prefetch
polled" mode, so this patch enables the transfer mode to be specified
in the device-tree.
---
.../devicetree/bindings/mtd/gpmc-nand.txt | 8 ++++++++
arch/arm/mach-omap2/gpmc.c | 14 ++++++++++++++
2 files changed, 22 insertions(+)
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
index e7f8d7e..cd4a19b 100644
--- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt
@@ -29,6 +29,13 @@ Optional properties:
"bch4" 4-bit BCH ecc code
"bch8" 8-bit BCH ecc code
+ - ti,nand-xfer-type: A string setting the data transfer type. One of:
+
+ "prefetch-polled" Prefetch polled mode (default)
+ "polled" Polled mode, without prefetch
+ "prefetch-dma" Prefetch enabled sDMA mode
+ "prefetch-irq" Prefetch enabled irq mode
+
- elm_id: Specifies elm device node. This is required to support BCH
error correction using ELM module.
@@ -55,6 +62,7 @@ Example for an AM33xx board:
reg = <0 0 0>; /* CS0, offset 0 */
nand-bus-width = <16>;
ti,nand-ecc-opt = "bch8";
+ ti,nand-xfer-type = "polled";
gpmc,sync-clk = <0>;
gpmc,cs-on = <0>;
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 410e1ba..2f47f76 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -1212,6 +1212,13 @@ static const char * const nand_ecc_opts[] = {
[OMAP_ECC_BCH8_CODE_HW] = "bch8",
};
+static const char * const nand_xfer_types[] = {
+ [NAND_OMAP_PREFETCH_POLLED] = "prefetch-polled",
+ [NAND_OMAP_POLLED] = "polled",
+ [NAND_OMAP_PREFETCH_DMA] = "prefetch-dma",
+ [NAND_OMAP_PREFETCH_IRQ] = "prefetch-irq",
+};
+
static int gpmc_probe_nand_child(struct platform_device *pdev,
struct device_node *child)
{
@@ -1241,6 +1248,13 @@ static int gpmc_probe_nand_child(struct
platform_device *pdev,
break;
}
+ if (!of_property_read_string(child, "ti,nand-xfer-type", &s))
+ for (val = 0; val < ARRAY_SIZE(nand_xfer_types); val++)
+ if (!strcasecmp(s, nand_xfer_types[val])) {
+ gpmc_nand_data->xfer_type = val;
+ break;
+ }
+
val = of_get_nand_bus_width(child);
if (val == 16)
gpmc_nand_data->devsize = NAND_BUSWIDTH_16;
--
1.7.9.5
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