Re: [PATCH v4 11/27] mtd: nand: omap: Clean up device tree support

From: Brian Norris
Date: Wed Dec 02 2015 - 23:30:56 EST


Hi Roger,

On Tue, Oct 06, 2015 at 01:35:48PM +0300, Roger Quadros wrote:
> Move NAND specific device tree parsing to NAND driver.
>
> The NAND controller node must have a compatible id, register space
> resource and interrupt resource.
>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>

This one's going to need rebased, as there are some conflicting of_node
changes in l2-mtd.git.

> ---
> v4: Warn if using older incompatible DT i.e. compatible property not present
> in nand node.
>
> arch/arm/mach-omap2/gpmc-nand.c | 5 +-
> drivers/memory/omap-gpmc.c | 143 +++++++--------------------
> drivers/mtd/nand/omap2.c | 136 +++++++++++++++++++++----
> include/linux/platform_data/mtd-nand-omap2.h | 3 +-
> 4 files changed, 155 insertions(+), 132 deletions(-)

Also, this is going to be hard to manage across trees, as you touch
three drivers all at once. Is it not possible to split any of this apart
better?

>
> diff --git a/arch/arm/mach-omap2/gpmc-nand.c b/arch/arm/mach-omap2/gpmc-nand.c
> index ffe646a..e07ca27 100644
> --- a/arch/arm/mach-omap2/gpmc-nand.c
> +++ b/arch/arm/mach-omap2/gpmc-nand.c
> @@ -95,10 +95,7 @@ int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
> gpmc_nand_res[1].start = gpmc_get_irq();
>
> memset(&s, 0, sizeof(struct gpmc_settings));
> - if (gpmc_nand_data->of_node)
> - gpmc_read_settings_dt(gpmc_nand_data->of_node, &s);
> - else
> - gpmc_set_legacy(gpmc_nand_data, &s);
> + gpmc_set_legacy(gpmc_nand_data, &s);
>
> s.device_nand = true;
>
> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
> index e75226d..318c187 100644
> --- a/drivers/memory/omap-gpmc.c
> +++ b/drivers/memory/omap-gpmc.c
> @@ -29,7 +29,6 @@
> #include <linux/of_device.h>
> #include <linux/of_platform.h>
> #include <linux/omap-gpmc.h>
> -#include <linux/mtd/nand.h>
> #include <linux/pm_runtime.h>
>
> #include <linux/platform_data/mtd-nand-omap2.h>
> @@ -1716,105 +1715,6 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
> of_property_read_bool(np, "gpmc,time-para-granularity");
> }
>
> -#if IS_ENABLED(CONFIG_MTD_NAND)
> -
> -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)
> -{
> - u32 val;
> - const char *s;
> - struct gpmc_timings gpmc_t;
> - struct omap_nand_platform_data *gpmc_nand_data;
> -
> - if (of_property_read_u32(child, "reg", &val) < 0) {
> - dev_err(&pdev->dev, "%s has no 'reg' property\n",
> - child->full_name);
> - return -ENODEV;
> - }
> -
> - gpmc_nand_data = devm_kzalloc(&pdev->dev, sizeof(*gpmc_nand_data),
> - GFP_KERNEL);
> - if (!gpmc_nand_data)
> - return -ENOMEM;
> -
> - gpmc_nand_data->cs = val;
> - gpmc_nand_data->of_node = child;
> -
> - /* Detect availability of ELM module */
> - gpmc_nand_data->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0);
> - if (gpmc_nand_data->elm_of_node == NULL)
> - gpmc_nand_data->elm_of_node =
> - of_parse_phandle(child, "elm_id", 0);
> -
> - /* select ecc-scheme for NAND */
> - if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) {
> - pr_err("%s: ti,nand-ecc-opt not found\n", __func__);
> - return -ENODEV;
> - }
> -
> - if (!strcmp(s, "sw"))
> - gpmc_nand_data->ecc_opt = OMAP_ECC_HAM1_CODE_SW;
> - else if (!strcmp(s, "ham1") ||
> - !strcmp(s, "hw") || !strcmp(s, "hw-romcode"))
> - gpmc_nand_data->ecc_opt =
> - OMAP_ECC_HAM1_CODE_HW;
> - else if (!strcmp(s, "bch4"))
> - if (gpmc_nand_data->elm_of_node)
> - gpmc_nand_data->ecc_opt =
> - OMAP_ECC_BCH4_CODE_HW;
> - else
> - gpmc_nand_data->ecc_opt =
> - OMAP_ECC_BCH4_CODE_HW_DETECTION_SW;
> - else if (!strcmp(s, "bch8"))
> - if (gpmc_nand_data->elm_of_node)
> - gpmc_nand_data->ecc_opt =
> - OMAP_ECC_BCH8_CODE_HW;
> - else
> - gpmc_nand_data->ecc_opt =
> - OMAP_ECC_BCH8_CODE_HW_DETECTION_SW;
> - else if (!strcmp(s, "bch16"))
> - if (gpmc_nand_data->elm_of_node)
> - gpmc_nand_data->ecc_opt =
> - OMAP_ECC_BCH16_CODE_HW;
> - else
> - pr_err("%s: BCH16 requires ELM support\n", __func__);
> - else
> - pr_err("%s: ti,nand-ecc-opt invalid value\n", __func__);
> -
> - /* select data transfer mode for NAND controller */
> - 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;
> - }
> -
> - gpmc_nand_data->flash_bbt = of_get_nand_on_flash_bbt(child);
> -
> - val = of_get_nand_bus_width(child);
> - if (val == 16)
> - gpmc_nand_data->devsize = NAND_BUSWIDTH_16;
> -
> - gpmc_read_timings_dt(child, &gpmc_t);
> - gpmc_nand_init(gpmc_nand_data, &gpmc_t);
> -
> - return 0;
> -}
> -#else
> -static int gpmc_probe_nand_child(struct platform_device *pdev,
> - struct device_node *child)
> -{
> - return 0;
> -}
> -#endif
> -
> #if IS_ENABLED(CONFIG_MTD_ONENAND)
> static int gpmc_probe_onenand_child(struct platform_device *pdev,
> struct device_node *child)
> @@ -1933,9 +1833,42 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
> goto err;
> }
>
> - ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width);
> - if (ret < 0)
> - goto err;
> + if (of_node_cmp(child->name, "nand") == 0) {
> + /* NAND specific setup */
> + u32 val;
> +
> + /* Warn about older DT blobs with no compatible property */
> + if (!of_property_read_bool(child, "compatible")) {
> + dev_warn(&pdev->dev,
> + "Incompatible NAND node: missing compatible");
> + ret = -EINVAL;
> + goto err;
> + }
> +
> + val = of_get_nand_bus_width(child);
> + switch (val) {
> + case 8:
> + gpmc_s.device_width = GPMC_DEVWIDTH_8BIT;
> + break;
> + case 16:
> + gpmc_s.device_width = GPMC_DEVWIDTH_16BIT;
> + break;
> + default:
> + dev_err(&pdev->dev, "%s: invalid 'nand-bus-width'\n",
> + child->name);
> + ret = -EINVAL;
> + goto err;
> + }
> +
> + /* disable write protect */
> + gpmc_configure(GPMC_CONFIG_WP, 0);
> + gpmc_s.device_nand = true;
> + } else {
> + ret = of_property_read_u32(child, "bank-width",
> + &gpmc_s.device_width);
> + if (ret < 0)
> + goto err;
> + }
>
> ret = gpmc_cs_program_settings(cs, &gpmc_s);
> if (ret < 0)
> @@ -2018,9 +1951,7 @@ static int gpmc_probe_dt(struct platform_device *pdev)
> if (!child->name)
> continue;
>
> - if (of_node_cmp(child->name, "nand") == 0)
> - ret = gpmc_probe_nand_child(pdev, child);
> - else if (of_node_cmp(child->name, "onenand") == 0)
> + if (of_node_cmp(child->name, "onenand") == 0)
> ret = gpmc_probe_onenand_child(pdev, child);
> else
> ret = gpmc_probe_generic_child(pdev, child);
> diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
> index c35405c..228f498 100644
> --- a/drivers/mtd/nand/omap2.c
> +++ b/drivers/mtd/nand/omap2.c
> @@ -24,6 +24,7 @@
> #include <linux/slab.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
> +#include <linux/of_mtd.h>
>
> #include <linux/mtd/nand_bch.h>
> #include <linux/platform_data/elm.h>
> @@ -177,6 +178,8 @@ struct omap_nand_info {
> struct gpmc_nand_regs reg;
> struct gpmc_nand_ops *ops;
> /* generated at runtime depending on ECC algorithm and layout selected */
> + bool flash_bbt;
> + /* generated at runtime depending on ECC algorithm and layout */
> struct nand_ecclayout oobinfo;
> /* fields specific for BCHx_HW ECC scheme */
> struct device *elm_dev;
> @@ -1668,10 +1671,84 @@ static bool omap2_nand_ecc_check(struct omap_nand_info *info,
> return true;
> }
>
> +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 omap_get_dt_info(struct device *dev, struct omap_nand_info *info)
> +{
> + struct device_node *child = dev->of_node;
> + int i;
> + const char *s;
> +
> + /* In old bindings, CS num is embedded in reg property */
> + if (of_property_read_u32(child, "reg", &info->gpmc_cs) < 0) {
> + dev_err(dev, "reg not found in DT\n");
> + return -EINVAL;
> + }
> +
> + /* detect availability of ELM module. Won't be present pre-OMAP4 */
> + info->elm_of_node = of_parse_phandle(child, "ti,elm-id", 0);
> + if (!info->elm_of_node)
> + dev_dbg(dev, "ti,elm-id not in DT\n");
> +
> + /* select ecc-scheme for NAND */
> + if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) {
> + dev_err(dev, "ti,nand-ecc-opt not found\n");
> + return -EINVAL;
> + }
> +
> + if (!strcmp(s, "sw")) {
> + info->ecc_opt = OMAP_ECC_HAM1_CODE_SW;
> + } else if (!strcmp(s, "ham1") ||
> + !strcmp(s, "hw") || !strcmp(s, "hw-romcode")) {
> + info->ecc_opt = OMAP_ECC_HAM1_CODE_HW;
> + } else if (!strcmp(s, "bch4")) {
> + if (info->elm_of_node)
> + info->ecc_opt = OMAP_ECC_BCH4_CODE_HW;
> + else
> + info->ecc_opt = OMAP_ECC_BCH4_CODE_HW_DETECTION_SW;
> + } else if (!strcmp(s, "bch8")) {
> + if (info->elm_of_node)
> + info->ecc_opt = OMAP_ECC_BCH8_CODE_HW;
> + else
> + info->ecc_opt = OMAP_ECC_BCH8_CODE_HW_DETECTION_SW;
> + } else if (!strcmp(s, "bch16")) {
> + info->ecc_opt = OMAP_ECC_BCH16_CODE_HW;
> + } else {
> + dev_err(dev, "unrecognized value for ti,nand-ecc-opt\n");
> + return -EINVAL;
> + }
> +
> + /* select data transfer mode */
> + if (!of_property_read_string(child, "ti,nand-xfer-type", &s)) {
> + for (i = 0; i < ARRAY_SIZE(nand_xfer_types); i++) {
> + if (!strcasecmp(s, nand_xfer_types[i])) {
> + info->xfer_type = i;
> + goto next;
> + }
> + }
> +
> + dev_err(dev, "unrecognized value for ti,nand-xfer-type\n");
> + return -EINVAL;
> + }
> +
> +next:
> + of_get_nand_on_flash_bbt(child);
> +
> + if (of_get_nand_bus_width(child) == 16)
> + info->devsize = NAND_BUSWIDTH_16;
> +
> + return 0;
> +}
> +
> static int omap_nand_probe(struct platform_device *pdev)
> {
> struct omap_nand_info *info;
> - struct omap_nand_platform_data *pdata;
> + struct omap_nand_platform_data *pdata = NULL;
> struct mtd_info *mtd;
> struct nand_chip *nand_chip;
> struct nand_ecclayout *ecclayout;
> @@ -1682,33 +1759,42 @@ static int omap_nand_probe(struct platform_device *pdev)
> unsigned oob_index;
> struct resource *res;
> struct mtd_part_parser_data ppdata = {};
> -
> - pdata = dev_get_platdata(&pdev->dev);
> - if (pdata == NULL) {
> - dev_err(&pdev->dev, "platform data missing\n");
> - return -ENODEV;
> - }
> + struct device *dev = &pdev->dev;
>
> info = devm_kzalloc(&pdev->dev, sizeof(struct omap_nand_info),
> GFP_KERNEL);
> if (!info)
> return -ENOMEM;
>
> - platform_set_drvdata(pdev, info);
> + info->pdev = pdev;
>
> + if (dev->of_node) {
> + if (omap_get_dt_info(dev, info))
> + return -EINVAL;
> + } else {
> + pdata = dev_get_platdata(&pdev->dev);
> + if (!pdata) {
> + dev_err(&pdev->dev, "platform data missing\n");
> + return -EINVAL;
> + }
> +
> + info->gpmc_cs = pdata->cs;
> + info->reg = pdata->reg;
> + info->of_node = pdata->of_node;
> + info->ecc_opt = pdata->ecc_opt;
> + info->dev_ready = pdata->dev_ready;
> + info->xfer_type = pdata->xfer_type;
> + info->devsize = pdata->devsize;
> + info->elm_of_node = pdata->elm_of_node;
> + info->flash_bbt = pdata->flash_bbt;
> + }
> +
> + platform_set_drvdata(pdev, info);
> info->ops = gpmc_omap_get_nand_ops(&info->reg, info->gpmc_cs);
> if (!info->ops) {
> dev_err(&pdev->dev, "Failed to get GPMC->NAND interface\n");
> return -ENODEV;
> }
> - info->pdev = pdev;
> - info->gpmc_cs = pdata->cs;
> - info->of_node = pdata->of_node;
> - info->ecc_opt = pdata->ecc_opt;
> - info->dev_ready = pdata->dev_ready;
> - info->xfer_type = pdata->xfer_type;
> - info->devsize = pdata->devsize;
> - info->elm_of_node = pdata->elm_of_node;
>
> mtd = &info->mtd;
> mtd->priv = &info->nand;
> @@ -1744,7 +1830,7 @@ static int omap_nand_probe(struct platform_device *pdev)
> nand_chip->chip_delay = 50;
> }
>
> - if (pdata->flash_bbt)
> + if (info->flash_bbt)
> nand_chip->bbt_options |= NAND_BBT_USE_FLASH | NAND_BBT_NO_OOB;
> else
> nand_chip->options |= NAND_SKIP_BBTSCAN;
> @@ -2049,9 +2135,13 @@ scan_tail:
> goto return_error;
> }
>
> - ppdata.of_node = pdata->of_node;
> - mtd_device_parse_register(mtd, NULL, &ppdata, pdata->parts,
> - pdata->nr_parts);
> + if (dev->of_node) {
> + ppdata.of_node = dev->of_node;

The latest l2-mtd.git changed how the partitions' of_node is passed. Now
this is handled by nand_set_flash_node().

> + mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
> +
> + } else {
> + mtd_device_register(mtd, pdata->parts, pdata->nr_parts);
> + }
>
> platform_set_drvdata(pdev, mtd);
>
> @@ -2083,11 +2173,17 @@ static int omap_nand_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static const struct of_device_id omap_nand_ids[] = {
> + { .compatible = "ti,omap2-nand", },
> + {},
> +};
> +
> static struct platform_driver omap_nand_driver = {
> .probe = omap_nand_probe,
> .remove = omap_nand_remove,
> .driver = {
> .name = DRIVER_NAME,
> + .of_match_table = of_match_ptr(omap_nand_ids),
> },
> };
>
> diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h
> index a067f58..ff27e5a 100644
> --- a/include/linux/platform_data/mtd-nand-omap2.h
> +++ b/include/linux/platform_data/mtd-nand-omap2.h
> @@ -76,11 +76,10 @@ struct omap_nand_platform_data {
> int devsize;
> enum omap_ecc ecc_opt;
>
> - /* for passing the partitions */
> - struct device_node *of_node;
> struct device_node *elm_of_node;
>
> /* deprecated */
> struct gpmc_nand_regs reg;
> + struct device_node *of_node;

I'm a little confused here. Do you have a mixed platform data / device
tree setup here? That's odd. (It also seems if that was really
necessary, you could have the board file set pdev->dev.of_node before
registering it, then you don't need this field.) But really, if you're
partly using device tree, can't you just convert completely? Or is this
a two-phase process, and you're planning to convert omap2 to full device
tree?

> };
> #endif

Brian
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