mtd: Add orion_nand devicetree bindings

Allow a NAND chip using the orion_nand driver to be described using devicetree.

Changes since last submission (V4) [Addressing comments by]:-
* WARN when bank-width is out of range [Andrew Lunn]

Changes since last submission (V3):-
* Document all parameters [Grant Likely]
* Convert bank-width to be in bytes
* Add explicit defaults for cle, ale and bank-width

Signed-off-by: Jamie Lentin <jm@lentin.co.uk>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

2 files changed, 94 insertions, 3 deletions

diff --git a/Documentation/devicetree/bindings/mtd/orion-nand.txt b/Documentation/devicetree/bindings/mtd/orion-nand.txt
new file mode 100644
index 000000000000..b2356b7d2fa4
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/orion-nand.txt
@@ -0,0 +1,50 @@
+NAND support for Marvell Orion SoC platforms
+
+Required properties:
+- compatible : "mrvl,orion-nand".
+- reg : Base physical address of the NAND and length of memory mapped
+        region
+
+Optional properties:
+- cle : Address line number connected to CLE. Default is 0
+- ale : Address line number connected to ALE. Default is 1
+- bank-width : Width in bytes of the device. Default is 1
+- chip-delay : Chip dependent delay for transferring data from array to read
+               registers in usecs
+
+The device tree may optionally contain sub-nodes describing partitions of the
+address space. See partition.txt for more detail.
+
+Example:
+
+nand@f4000000 {
+        #address-cells = <1>;
+        #size-cells = <1>;
+        cle = <0>;
+        ale = <1>;
+        bank-width = <1>;
+        chip-delay = <25>;
+        compatible = "mrvl,orion-nand";
+        reg = <0xf4000000 0x400>;
+
+        partition@0 {
+                label = "u-boot";
+                reg = <0x0000000 0x100000>;
+                read-only;
+        };
+
+        partition@100000 {
+                label = "uImage";
+                reg = <0x0100000 0x200000>;
+        };
+
+        partition@300000 {
+                label = "dtb";
+                reg = <0x0300000 0x100000>;
+        };
+
+        partition@400000 {
+                label = "root";
+                reg = <0x0400000 0x7d00000>;
+        };
+};
diff --git a/drivers/mtd/nand/orion_nand.c b/drivers/mtd/nand/orion_nand.c
index 1d3bfb26080c..0f50ef38b87b 100644
--- a/drivers/mtd/nand/orion_nand.c
+++ b/drivers/mtd/nand/orion_nand.c
@@ -13,6 +13,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/of.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
 #include <linux/mtd/partitions.h>
@@ -74,11 +75,13 @@ static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 static int __init orion_nand_probe(struct platform_device *pdev)
 {
         struct mtd_info *mtd;
+        struct mtd_part_parser_data ppdata = {};
         struct nand_chip *nc;
         struct orion_nand_data *board;
         struct resource *res;
         void __iomem *io_base;
         int ret = 0;
+        u32 val = 0;
 
         nc = kzalloc(sizeof(struct nand_chip) + sizeof(struct mtd_info), GFP_KERNEL);
         if (!nc) {
@@ -101,7 +104,32 @@ static int __init orion_nand_probe(struct platform_device *pdev)
                 goto no_res;
         }
 
-        board = pdev->dev.platform_data;
+        if (pdev->dev.of_node) {
+                board = devm_kzalloc(&pdev->dev, sizeof(struct orion_nand_data),
+                                        GFP_KERNEL);
+                if (!board) {
+                        printk(KERN_ERR "orion_nand: failed to allocate board structure.\n");
+                        ret = -ENOMEM;
+                        goto no_res;
+                }
+                if (!of_property_read_u32(pdev->dev.of_node, "cle", &val))
+                        board->cle = (u8)val;
+                else
+                        board->cle = 0;
+                if (!of_property_read_u32(pdev->dev.of_node, "ale", &val))
+                        board->ale = (u8)val;
+                else
+                        board->ale = 1;
+                if (!of_property_read_u32(pdev->dev.of_node,
+                                                "bank-width", &val))
+                        board->width = (u8)val * 8;
+                else
+                        board->width = 8;
+                if (!of_property_read_u32(pdev->dev.of_node,
+                                                "chip-delay", &val))
+                        board->chip_delay = (u8)val;
+        } else
+                board = pdev->dev.platform_data;
 
         mtd->priv = nc;
         mtd->owner = THIS_MODULE;
@@ -115,6 +143,10 @@ static int __init orion_nand_probe(struct platform_device *pdev)
         if (board->chip_delay)
                 nc->chip_delay = board->chip_delay;
 
+        WARN(board->width > 16,
+                "%d bit bus width out of range",
+                board->width);
+
         if (board->width == 16)
                 nc->options |= NAND_BUSWIDTH_16;
 
@@ -129,8 +161,9 @@ static int __init orion_nand_probe(struct platform_device *pdev)
         }
 
         mtd->name = "orion_nand";
-        ret = mtd_device_parse_register(mtd, NULL, NULL, board->parts,
-                                        board->nr_parts);
+        ppdata.of_node = pdev->dev.of_node;
+        ret = mtd_device_parse_register(mtd, NULL, &ppdata,
+                        board->parts, board->nr_parts);
         if (ret) {
                 nand_release(mtd);
                 goto no_dev;
@@ -161,11 +194,19 @@ static int __devexit orion_nand_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_OF
+static struct of_device_id orion_nand_of_match_table[] = {
+        { .compatible = "mrvl,orion-nand", },
+        {},
+};
+#endif
+
 static struct platform_driver orion_nand_driver = {
         .remove         = __devexit_p(orion_nand_remove),
         .driver         = {
                 .name   = "orion_nand",
                 .owner  = THIS_MODULE,
+                .of_match_table = of_match_ptr(orion_nand_of_match_table),
         },
 };