[PATCH 3/3] mtd: s3c2410: parse the device configuration from OF node

Sergio Prado
2016-10-05T23:47:39Z

Allows configuring Samsung's s3c2410 memory controller using a
devicetree.

Signed-off-by: Sergio Prado <sergio.prado@e-labworks.com>
---
drivers/mtd/nand/s3c2410.c | 171 ++++++++++++++++++++++---
include/linux/platform_data/mtd-nand-s3c2410.h | 1 +
2 files changed, 156 insertions(+), 16 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index 174ac9dc4265..352cf2656bc8 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)
@@ -811,6 +833,8 @@ 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;
@@ -859,12 +883,35 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
chip->ecc.mode = info->platform->ecc_mode;

/* If you use u-boot BBT creation code, specifying this flag will
- * let the kernel fish out the BBT from the NAND, and also skip the
- * full NAND scan that can take 1/2s or so. Little things... */
- if (set->flash_bbt) {
+ * let the kernel fish out the BBT from the NAND */
+ if (set->flash_bbt)
chip->bbt_options |= NAND_BBT_USE_FLASH;
- chip->options |= NAND_SKIP_BBTSCAN;
- }
+}
+
+static int s3c2410_nand_init_timings(struct s3c2410_nand_info *info,
+ struct nand_chip *chip)
+{
+ struct s3c2410_platform_nand *pdata = info->platform;
+ const struct nand_sdr_timings *t;
+ int tacls, mode;
+
+ mode = onfi_get_async_timing_mode(chip);
+ if (mode == ONFI_TIMING_MODE_UNKNOWN)
+ mode = chip->onfi_timing_mode_default;
+
+ t = onfi_async_timing_mode_to_sdr_timings(mode);
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+
+ tacls = t->tCLS_min - t->tWP_min;
+ if (tacls < 0)
+ tacls = 0;
+
+ pdata->tacls = DIV_ROUND_UP(tacls, 1000);
+ pdata->twrph0 = DIV_ROUND_UP(t->tWP_min, 1000);
+ pdata->twrph1 = DIV_ROUND_UP(t->tCLH_min, 1000);
+
+ return 0;
}

/**
@@ -881,7 +928,9 @@ static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
static int s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
struct s3c2410_nand_mtd *nmtd)
{
+ struct device_node *np = info->device->of_node;
struct nand_chip *chip = &nmtd->chip;
+ int ret;

switch (chip->ecc.mode) {

@@ -943,6 +992,90 @@ static int s3c2410_nand_update_chip(struct s3c2410_nand_info *info,
return -EINVAL;
}

+ if (chip->bbt_options & NAND_BBT_USE_FLASH)
+ chip->options |= NAND_SKIP_BBTSCAN;
+
+ /* read timings from nand_sdr_timings when booting with a device tree */
+ if (np) {
+ ret = s3c2410_nand_init_timings(info, chip);
+ if (ret) {
+ dev_err(info->device,
+ "could not configure chip timings: %d\n", ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+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;
+ struct s3c2410_nand_set *sets;
+
+ devtype_data = of_device_get_match_data(&pdev->dev);
+ if (!devtype_data)
+ return -ENODEV;
+
+ info->cpu_type = devtype_data->type;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdev->dev.platform_data = pdata;
+
+ 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;
+
+ of_node_get(child);
+
+ sets++;
+ }
+
+ return 0;
+}
+
+static int 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;
+
return 0;
}

@@ -955,8 +1088,7 @@ static int 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;
@@ -966,8 +1098,6 @@ 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;
@@ -990,6 +1120,16 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)

s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);

+ if (pdev->dev.of_node)
+ err = s3c24xx_nand_probe_dt(pdev);
+ else
+ err = s3c24xx_nand_probe_pdata(pdev);
+
+ if (err)
+ goto exit_error;
+
+ plat = to_nand_plat(pdev);
+
/* allocate and map the resource */

/* currently we assume we have the one resource */
@@ -998,7 +1138,6 @@ 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)) {
@@ -1008,12 +1147,6 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)

dev_dbg(&pdev->dev, "mapped registers at %p\n", info->regs);

- /* initialise the hardware */
-
- err = s3c2410_nand_inithw(info);
- if (err != 0)
- goto exit_error;
-
sets = (plat != NULL) ? plat->sets : NULL;
nr_sets = (plat != NULL) ? plat->nr_sets : 1;

@@ -1057,6 +1190,11 @@ static int s3c24xx_nand_probe(struct platform_device *pdev)
sets++;
}

+ /* initialise the hardware */
+ err = s3c2410_nand_inithw(info);
+ if (err != 0)
+ goto exit_error;
+
err = s3c2410_nand_cpufreq_register(info);
if (err < 0) {
dev_err(&pdev->dev, "failed to init cpufreq support\n");
@@ -1157,6 +1295,7 @@ 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 729af13d1773..f01659026b26 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