Re: [FOR 3.4 PATCH 5/6] atmel/nand: add DT support

Simon Glass
2012-01-29T18:31:56Z

Hi,

On Fri, Jan 27, 2012 at 9:10 PM, Jean-Christophe PLAGNIOL-VILLARD
<plagnioj@jcrosoft.com> wrote:
> use a local copy of board informatin and fill with DT data
>
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
> Cc: devicetree-discuss@lists.ozlabs.org
> Cc: linux-mtd@lists.infradead.org
> ---
>  .../devicetree/bindings/mtd/atmel-nand.txt         |   41 ++++++++
>  drivers/mtd/nand/atmel_nand.c                      |  107 ++++++++++++++++----
>  2 files changed, 130 insertions(+), 18 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/mtd/atmel-nand.txt
>
> diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> new file mode 100644
> index 0000000..a910ab9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> @@ -0,0 +1,41 @@
> +Atmel NAND flash
> +
> +Required properties:
> +- compatible : "atmel,at91rm9200-nand".
> +- reg : should specify localbus address and size used for the chip,
> +       and if availlable the ECC.
> +- atmel,nand-addr-offset : offset for the address latch.
> +- atmel,nand-cmd-offset : offset for the command latch.
> +- #address-cells, #size-cells : Must be present if the device has sub-nodes
> +  representing partitions.
> +
> +- gpios : specifies the gpio pins to control the NAND device. detect is an
> +  optional gpio and may be set to 0 if not present.

What does this mean please? What is 'detect' and what 'control' do the
gpios provide?

Below you have two GPIOs pioC 13 and pioC 14. I think the binding
should document the two GPIOs, the order, and what they are for.

> +
> +Optional properties:
> +- nand-ecc-mode : String, operation mode of the NAND ecc mode, soft by default.
> +  Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first",
> +  "soft_bch".
> +- nand-bus-width : 8 or 16 bus width if not present 8
> +- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false
> +
> +Examples:
> +nand0: nand@40000000,0 {
> +       compatible = "atmel,at91rm9200-nand";
> +       #address-cells = <1>;
> +       #size-cells = <1>;
> +       reg = <0x40000000 0x10000000
> +              0xffffe800 0x200
> +             >;
> +       atmel,nand-addr-offset = <21>;
> +       atmel,nand-cmd-offset = <22>;
> +       nand-on-flash-bbt = <1>;
> +       nand-ecc-mode = "soft";
> +       gpios = <&pioC 13 0
> +                &pioC 14 0
> +                0

Sorry, I haven't seen this before, perhaps it is a standard thing in
Linux. Does 0 mean end of list? Can we not just use the property's
size value for this?

Regards,
Simon

> +               >;
> +       partition@0 {
> +               ...
> +       };
> +};
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index d3bde9b..ea7643a 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -27,6 +27,10 @@
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
>  #include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of_mtd.h>
>  #include <linux/mtd/mtd.h>
>  #include <linux/mtd/nand.h>
>  #include <linux/mtd/partitions.h>
> @@ -83,7 +87,7 @@ struct atmel_nand_host {
>        struct mtd_info         mtd;
>        void __iomem            *io_base;
>        dma_addr_t              io_phys;
> -       struct atmel_nand_data  *board;
> +       struct atmel_nand_data  board;
>        struct device           *dev;
>        void __iomem            *ecc;
>
> @@ -101,8 +105,8 @@ static int cpu_has_dma(void)
>  */
>  static void atmel_nand_enable(struct atmel_nand_host *host)
>  {
> -       if (gpio_is_valid(host->board->enable_pin))
> -               gpio_set_value(host->board->enable_pin, 0);
> +       if (gpio_is_valid(host->board.enable_pin))
> +               gpio_set_value(host->board.enable_pin, 0);
>  }
>
>  /*
> @@ -110,8 +114,8 @@ static void atmel_nand_enable(struct atmel_nand_host *host)
>  */
>  static void atmel_nand_disable(struct atmel_nand_host *host)
>  {
> -       if (gpio_is_valid(host->board->enable_pin))
> -               gpio_set_value(host->board->enable_pin, 1);
> +       if (gpio_is_valid(host->board.enable_pin))
> +               gpio_set_value(host->board.enable_pin, 1);
>  }
>
>  /*
> @@ -132,9 +136,9 @@ static void atmel_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl
>                return;
>
>        if (ctrl & NAND_CLE)
> -               writeb(cmd, host->io_base + (1 << host->board->cle));
> +               writeb(cmd, host->io_base + (1 << host->board.cle));
>        else
> -               writeb(cmd, host->io_base + (1 << host->board->ale));
> +               writeb(cmd, host->io_base + (1 << host->board.ale));
>  }
>
>  /*
> @@ -145,8 +149,8 @@ static int atmel_nand_device_ready(struct mtd_info *mtd)
>        struct nand_chip *nand_chip = mtd->priv;
>        struct atmel_nand_host *host = nand_chip->priv;
>
> -       return gpio_get_value(host->board->rdy_pin) ^
> -                !!host->board->rdy_pin_active_low;
> +       return gpio_get_value(host->board.rdy_pin) ^
> +                !!host->board.rdy_pin_active_low;
>  }
>
>  static void dma_complete_func(void *completion)
> @@ -432,6 +436,54 @@ static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
>        }
>  }
>
> +static int __devinit atmel_of_init_port(struct atmel_nand_host *host,
> +                                        struct device_node *np)
> +{
> +       u32 val;
> +       int ecc_mode;
> +       struct atmel_nand_data *board = &host->board;
> +       enum of_gpio_flags flags;
> +
> +       if (of_property_read_u32(np, "atmel,nand-addr-offset", &val) == 0) {
> +               if (val >= 32) {
> +                       dev_err(host->dev, "invalid addr-offset %u\n", val);
> +                       return -EINVAL;
> +               }
> +               board->ale = val;
> +       }
> +
> +       if (of_property_read_u32(np, "atmel,nand-cmd-offset", &val) == 0) {
> +               if (val >= 32) {
> +                       dev_err(host->dev, "invalid cmd-offset %u\n", val);
> +                       return -EINVAL;
> +               }
> +               board->cle = val;
> +       }
> +
> +       ecc_mode = of_get_nand_ecc_mode(np);
> +
> +       if (ecc_mode < 0)
> +               board->ecc_mode = NAND_ECC_SOFT;
> +       else
> +               board->ecc_mode = ecc_mode;
> +
> +       board->on_flash_bbt = of_get_nand_on_flash_bbt(np);
> +
> +       if (of_get_nand_bus_width(np) == 16)
> +               board->bus_width_16 = 1;
> +
> +       board->rdy_pin = of_get_gpio_flags(np, 0, &flags);
> +       if (flags == OF_GPIO_ACTIVE_LOW)
> +               board->rdy_pin_active_low = 1;
> +       else
> +               board->rdy_pin_active_low = 0;
> +
> +       board->enable_pin = of_get_gpio(np, 1);
> +       board->det_pin = of_get_gpio(np, 2);
> +
> +       return 0;
> +}
> +
>  /*
>  * Probe for the NAND device.
>  */
> @@ -442,6 +494,7 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>        struct nand_chip *nand_chip;
>        struct resource *regs;
>        struct resource *mem;
> +       struct mtd_part_parser_data ppdata = {};
>        int res;
>
>        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> @@ -468,8 +521,15 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>
>        mtd = &host->mtd;
>        nand_chip = &host->nand_chip;
> -       host->board = pdev->dev.platform_data;
>        host->dev = &pdev->dev;
> +       if (pdev->dev.of_node) {
> +               res = atmel_of_init_port(host, pdev->dev.of_node);
> +               if (res)
> +                       goto err_nand_ioremap;
> +       } else {
> +               memcpy(&host->board, pdev->dev.platform_data,
> +                      sizeof(struct atmel_nand_data));
> +       }
>
>        nand_chip->priv = host;         /* link the private data structures */
>        mtd->priv = nand_chip;
> @@ -480,10 +540,10 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>        nand_chip->IO_ADDR_W = host->io_base;
>        nand_chip->cmd_ctrl = atmel_nand_cmd_ctrl;
>
> -       if (gpio_is_valid(host->board->rdy_pin))
> +       if (gpio_is_valid(host->board.rdy_pin))
>                nand_chip->dev_ready = atmel_nand_device_ready;
>
> -       nand_chip->ecc.mode = host->board->ecc_mode;
> +       nand_chip->ecc.mode = host->board.ecc_mode;
>
>        regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
>        if (!regs && nand_chip->ecc.mode == NAND_ECC_HW) {
> @@ -508,7 +568,7 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>
>        nand_chip->chip_delay = 20;             /* 20us command delay time */
>
> -       if (host->board->bus_width_16)  /* 16-bit bus width */
> +       if (host->board.bus_width_16)   /* 16-bit bus width */
>                nand_chip->options |= NAND_BUSWIDTH_16;
>
>        nand_chip->read_buf = atmel_read_buf;
> @@ -517,15 +577,15 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>        platform_set_drvdata(pdev, host);
>        atmel_nand_enable(host);
>
> -       if (gpio_is_valid(host->board->det_pin)) {
> -               if (gpio_get_value(host->board->det_pin)) {
> +       if (gpio_is_valid(host->board.det_pin)) {
> +               if (gpio_get_value(host->board.det_pin)) {
>                        printk(KERN_INFO "No SmartMedia card inserted.\n");
>                        res = -ENXIO;
>                        goto err_no_card;
>                }
>        }
>
> -       if (host->board->on_flash_bbt || on_flash_bbt) {
> +       if (host->board.on_flash_bbt || on_flash_bbt) {
>                printk(KERN_INFO "atmel_nand: Use On Flash BBT\n");
>                nand_chip->bbt_options |= NAND_BBT_USE_FLASH;
>        }
> @@ -600,8 +660,9 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
>        }
>
>        mtd->name = "atmel_nand";
> -       res = mtd_device_parse_register(mtd, NULL, 0,
> -                       host->board->parts, host->board->num_parts);
> +       ppdata.of_node = pdev->dev.of_node;
> +       res = mtd_device_parse_register(mtd, NULL, &ppdata,
> +                       host->board.parts, host->board.num_parts);
>        if (!res)
>                return res;
>
> @@ -645,11 +706,21 @@ static int __exit atmel_nand_remove(struct platform_device *pdev)
>        return 0;
>  }
>
> +#if defined(CONFIG_OF)
> +static const struct of_device_id atmel_nand_dt_ids[] = {
> +       { .compatible = "atmel,at91rm9200-nand" },
> +       { /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, atmel_nand_dt_ids);
> +#endif
> +
>  static struct platform_driver atmel_nand_driver = {
>        .remove         = __exit_p(atmel_nand_remove),
>        .driver         = {
>                .name   = "atmel_nand",
>                .owner  = THIS_MODULE,
> +               .of_match_table = of_match_ptr(atmel_nand_dt_ids),
>        },
>  };
>
> --
> 1.7.7
>
>
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