[PATCH] mtd: s3c2410: add device tree support

From: Sergio Prado
Date: Sat Sep 17 2016 - 11:23:39 EST


Tested on FriendlyARM Mini2440

Signed-off-by: Sergio Prado <sergio.prado@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/mtd/samsung-s3c2410.txt | 70 +++++++++++
drivers/mtd/nand/s3c2410.c | 129 ++++++++++++++++++++-
include/linux/platform_data/mtd-nand-s3c2410.h | 1 +
3 files changed, 195 insertions(+), 5 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt

diff --git a/Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt b/Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt
new file mode 100644
index 000000000000..1c39f6cf483b
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/samsung-s3c2410.txt
@@ -0,0 +1,70 @@
+* Samsung S3C2410 and compatible NAND flash controller
+
+Required properties:
+- compatible : The possible values are:
+ "samsung,s3c2410-nand"
+ "samsung,s3c2412-nand"
+ "samsung,s3c2440-nand"
+ "samsung,s3c6400-nand"
+- reg : register's location and length.
+- #address-cells, #size-cells : see nand.txt
+- clocks : phandle to the nand controller clock
+- clock-names : must contain "nand"
+
+Optional properties:
+- samsung,tacls : time for active CLE/ALE to nWE/nOE
+- samsung,twrph0 : active time for nWE/nOE
+- samsung,twrph1 : time for release CLE/ALE from nWE/nOE inactive
+- samsung,ignore_unset_ecc : boolean to ignore error when we have
+ 0xff,0xff,0xff read ECC, on the
+ assumption that it is an un-eccd page
+
+Optional children nodes:
+Children nodes representing the available nand chips.
+
+Optional children properties:
+- nand-ecc-mode : see nand.txt
+- nand-on-flash-bbt : see nand.txt
+
+Each children device node may optionally contain a 'partitions' sub-node,
+which further contains sub-nodes describing the flash partition mapping.
+See partition.txt for more detail.
+
+Example:
+
+nand@4e000000 {
+ compatible = "samsung,s3c2440-nand";
+ reg = <0x4e000000 0x40>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ clocks = <&clocks HCLK_NAND>;
+ clock-names = "nand";
+
+ samsung,tacls = <0>;
+ samsung,twrph0 = <25>;
+ samsung,twrph1 = <15>;
+ samsung,ignore_unset_ecc;
+
+ nand@0 {
+ nand-ecc-mode = "soft";
+ nand-on-flash-bbt;
+
+ partitions {
+ compatible = "fixed-partitions";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ partition@0 {
+ label = "u-boot";
+ reg = <0 0x040000>;
+ };
+
+ partition@40000 {
+ label = "kernel";
+ reg = <0x040000 0x500000>;
+ };
+ };
+ };
+};
diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index d9309cf0ce2e..ecbb9c9c1e9a 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -39,6 +39,8 @@
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/cpufreq.h>
+#include <linux/of.h>
+#include <linux/of_device.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
@@ -185,6 +187,26 @@ struct s3c2410_nand_info {
#endif
};

+struct s3c24XX_nand_devtype_data {
+ enum s3c_cpu_type type;
+};
+
+struct s3c24XX_nand_devtype_data s3c2410_nand_devtype_data = {
+ .type = TYPE_S3C2410,
+};
+
+struct s3c24XX_nand_devtype_data s3c2412_nand_devtype_data = {
+ .type = TYPE_S3C2412,
+};
+
+struct s3c24XX_nand_devtype_data s3c2440_nand_devtype_data = {
+ .type = TYPE_S3C2440,
+};
+
+struct s3c24XX_nand_devtype_data s3c6400_nand_devtype_data = {
+ .type = TYPE_S3C2412,
+};
+
/* conversion functions */

static struct s3c2410_nand_mtd *s3c2410_nand_mtd_toours(struct mtd_info *mtd)
@@ -813,6 +835,8 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
struct nand_chip *chip = &nmtd->chip;
void __iomem *regs = info->regs;

+ nand_set_flash_node(chip, set->of_node);
+
chip->write_buf = s3c2410_nand_write_buf;
chip->read_buf = s3c2410_nand_read_buf;
chip->select_chip = s3c2410_nand_select_chip;
@@ -947,6 +971,96 @@ static void s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
}
}

+#ifdef CONFIG_OF_MTD
+static const struct of_device_id s3c24xx_nand_dt_ids[] = {
+ {
+ .compatible = "samsung,s3c2410-nand",
+ .data = &s3c2410_nand_devtype_data,
+ }, {
+ .compatible = "samsung,s3c2412-nand",
+ .data = &s3c2412_nand_devtype_data,
+ }, {
+ .compatible = "samsung,s3c2440-nand",
+ .data = &s3c2440_nand_devtype_data,
+ }, {
+ .compatible = "samsung,s3c6400-nand",
+ .data = &s3c6400_nand_devtype_data,
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, s3c24xx_nand_dt_ids);
+
+static int s3c24xx_nand_probe_dt(struct platform_device *pdev)
+{
+ const struct s3c24XX_nand_devtype_data *devtype_data;
+ struct s3c2410_platform_nand *pdata;
+ struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
+ struct device_node *np = pdev->dev.of_node, *child;
+ const struct of_device_id *of_id;
+ struct s3c2410_nand_set *sets;
+
+ of_id = of_match_device(s3c24xx_nand_dt_ids, &pdev->dev);
+ if (!of_id)
+ return 1;
+
+ devtype_data = of_id->data;
+ info->cpu_type = devtype_data->type;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdev->dev.platform_data = pdata;
+
+ of_property_read_u32(np, "samsung,tacls", &pdata->tacls);
+ of_property_read_u32(np, "samsung,twrph0", &pdata->twrph0);
+ of_property_read_u32(np, "samsung,twrph1", &pdata->twrph1);
+
+ if (of_get_property(np, "samsung,ignore_unset_ecc", NULL))
+ pdata->ignore_unset_ecc = 1;
+
+ pdata->nr_sets = of_get_child_count(np);
+ if (!pdata->nr_sets)
+ return 0;
+
+ sets = devm_kzalloc(&pdev->dev, sizeof(*sets) * pdata->nr_sets,
+ GFP_KERNEL);
+ if (!sets)
+ return -ENOMEM;
+
+ pdata->sets = sets;
+
+ for_each_available_child_of_node(np, child) {
+
+ sets->name = (char *)child->name;
+ sets->of_node = child;
+ sets->nr_chips = 1;
+
+ if (!of_property_match_string(child, "nand-ecc-mode", "none"))
+ sets->disable_ecc = 1;
+
+ if (of_get_property(child, "nand-on-flash-bbt", NULL))
+ sets->flash_bbt = 1;
+
+ sets++;
+ }
+
+ return 0;
+}
+#else
+static int s3c24xx_nand_probe_dt(struct platform_device *pdev)
+{
+ return 1;
+}
+#endif
+
+static void s3c24xx_nand_probe_pdata(struct platform_device *pdev)
+{
+ struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
+
+ info->cpu_type = platform_get_device_id(pdev)->driver_data;
+}
+
/* s3c24xx_nand_probe
*
* called by device layer when it finds a device matching
@@ -956,8 +1070,7 @@ static void s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
*/
static int s3c24xx_nand_probe(struct platform_device *pdev)
{
- struct s3c2410_platform_nand *plat = to_nand_plat(pdev);
- enum s3c_cpu_type cpu_type;
+ struct s3c2410_platform_nand *plat;
struct s3c2410_nand_info *info;
struct s3c2410_nand_mtd *nmtd;
struct s3c2410_nand_set *sets;
@@ -967,8 +1080,6 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
int nr_sets;
int setno;

- cpu_type = platform_get_device_id(pdev)->driver_data;
-
info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
if (info == NULL) {
err = -ENOMEM;
@@ -991,6 +1102,14 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)

s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);

+ err = s3c24xx_nand_probe_dt(pdev);
+ if (err > 0)
+ s3c24xx_nand_probe_pdata(pdev);
+ else if (err < 0)
+ goto exit_error;
+
+ plat = to_nand_plat(pdev);
+
/* allocate and map the resource */

/* currently we assume we have the one resource */
@@ -999,7 +1118,6 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)

info->device = &pdev->dev;
info->platform = plat;
- info->cpu_type = cpu_type;

info->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(info->regs)) {
@@ -1156,6 +1274,7 @@ static struct platform_driver s3c24xx_nand_driver = {
.id_table = s3c24xx_driver_ids,
.driver = {
.name = "s3c24xx-nand",
+ .of_match_table = s3c24xx_nand_dt_ids,
},
};

diff --git a/include/linux/platform_data/mtd-nand-s3c2410.h b/include/linux/platform_data/mtd-nand-s3c2410.h
index c55e42ee57fa..9d20871e4bbd 100644
--- a/include/linux/platform_data/mtd-nand-s3c2410.h
+++ b/include/linux/platform_data/mtd-nand-s3c2410.h
@@ -40,6 +40,7 @@ struct s3c2410_nand_set {
char *name;
int *nr_map;
struct mtd_partition *partitions;
+ struct device_node *of_node;
};

struct s3c2410_platform_nand {
--
1.9.1