On Wed, Jan 14, 2015 at 05:41:49PM -0600, Aaron Sierra wrote:
> From: Jordan Friendshuh <jfriendshuh@xxxxxxxxxxx>
>
> Support the generic nand-ecc-mode, nand-ecc-strength, and
> nand-ecc-step-size device-tree properties with the Freescale UPM NAND
> driver.
>
> This patch preserves the default software ECC mode while adding the
> ability to use BCH ECC for larger NAND devices.
>
> Signed-off-by: Jordan Friendshuh <jfriendshuh@xxxxxxxxxxx>
> Signed-off-by: Aaron Sierra <asierra@xxxxxxxxxxx>
> ---
> v2:
> * Now using ECC mode and strength helpers from of_mtd.h
> * ECC mode and strength checking is more robust
> v3 (resent due to [PATCH 1/2] v2 update):
> * Require nand-ecc-step-size for soft_bch.
> * Simplify mode/strength/step parameter checking.
>
> .../devicetree/bindings/mtd/fsl-upm-nand.txt | 32 +++++++++++
> drivers/mtd/nand/Kconfig | 1 +
> drivers/mtd/nand/fsl_upm.c | 66 ++++++++++++++++++++--
I was thinking about this a bit more, and it seems like we could really
just factor this all into the core nand_base code with something like
the following patch. It could possibly use some smarter logic to rule
out certain combinations (but some of those are already caught in
nand_scan_tail() anyway). What do you think?
diff --git a/drivers/mtd/nand/fsl_upm.c b/drivers/mtd/nand/fsl_upm.c
index 72755d7ec25d..fc4834946233 100644
--- a/drivers/mtd/nand/fsl_upm.c
+++ b/drivers/mtd/nand/fsl_upm.c
@@ -181,6 +181,7 @@ static int fun_chip_init(struct fsl_upm_nand *fun,
flash_np = of_get_next_child(upm_np, NULL);
if (!flash_np)
return -ENODEV;
+ fun->chip.dn = flash_np;
fun->mtd.name = kasprintf(GFP_KERNEL, "0x%llx.%s", (u64)io_res->start,
flash_np->name);
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 3f24b587304f..b701c3f23da1 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -48,6 +48,7 @@
#include <linux/leds.h>
#include <linux/io.h>
#include <linux/mtd/partitions.h>
+#include <linux/of_mtd.h>
/* Define default oob placement schemes for large and small page devices */
static struct nand_ecclayout nand_oob_8 = {
@@ -3780,6 +3781,33 @@ ident_done:
return type;
}
+static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip,
+ struct device_node *dn)
+{
+ int ecc_mode, ecc_strength, ecc_step;
+
+ if (of_get_nand_bus_width(dn) == 16)
+ chip->options |= NAND_BUSWIDTH_16;
+
+ if (of_get_nand_on_flash_bbt(dn))
+ chip->bbt_options |= NAND_BBT_USE_FLASH;
+
+ ecc_mode = of_get_nand_ecc_mode(dn);
+ ecc_strength = of_get_nand_ecc_strength(dn);
+ ecc_step = of_get_nand_ecc_step_size(dn);
+
+ if (ecc_mode >= 0)
+ chip->ecc.mode = ecc_mode;
+
+ if (ecc_strength >= 0)
+ chip->ecc.strength = ecc_strength;
+
+ if (ecc_step > 0)
+ chip->ecc.size = ecc_step;
+
+ return 0;
+}
+
/**
* nand_scan_ident - [NAND Interface] Scan for the NAND device
* @mtd: MTD device structure
@@ -3797,6 +3825,13 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,
int i, nand_maf_id, nand_dev_id;
struct nand_chip *chip = mtd->priv;
struct nand_flash_dev *type;
+ int ret;
+
+ if (chip->dn) {
+ ret = nand_dt_init(mtd, chip, chip->dn);
+ if (ret)
+ return ret;
+ }
/* Set the default functions */
nand_set_defaults(chip, chip->options & NAND_BUSWIDTH_16);
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 3d4ea7eb2b68..e0f40e12a2c8 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -26,6 +26,8 @@
struct mtd_info;
struct nand_flash_dev;
+struct device_node;
+
/* Scan and identify a NAND device */
extern int nand_scan(struct mtd_info *mtd, int max_chips);
/*
@@ -542,6 +544,7 @@ struct nand_buffers {
* flash device
* @IO_ADDR_W: [BOARDSPECIFIC] address to write the 8 I/O lines of the
* flash device.
+ * @dn: [BOARDSPECIFIC] device node describing this instance
* @read_byte: [REPLACEABLE] read one byte from the chip
* @read_word: [REPLACEABLE] read one word from the chip
* @write_byte: [REPLACEABLE] write a single byte to the chip on the
@@ -644,6 +647,8 @@ struct nand_chip {
void __iomem *IO_ADDR_R;
void __iomem *IO_ADDR_W;
+ struct device_node *dn;
+
uint8_t (*read_byte)(struct mtd_info *mtd);
u16 (*read_word)(struct mtd_info *mtd);
void (*write_byte)(struct mtd_info *mtd, uint8_t byte);
--
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