[U-Boot] [PATCH v4 2/3] cfi_flash: convert to driver model

Simon Glass sjg at chromium.org
Fri Nov 6 04:15:39 CET 2015


Hi Thomas,

On 3 November 2015 at 06:09, Thomas Chou <thomas at wytron.com.tw> wrote:
> Convert cfi flash to driver model.
>
> Signed-off-by: Thomas Chou <thomas at wytron.com.tw>
> ---
> v2
>   add dts binding.
>   add more help to Kconfig.
>   move struct platdata to top of file as Simon suggested.
> v3
>   change to MTD uclass.
> v4
>   fix fdt addr and size cells in cfi_flash_probe().
>   move probe uclass to cfi_flash_dm_init().
>   add comment as suggested by Stefan.
>
>  doc/device-tree-bindings/mtd/mtd-physmap.txt | 88 ++++++++++++++++++++++++++++
>  drivers/mtd/Kconfig                          | 11 ++++
>  drivers/mtd/cfi_flash.c                      | 81 +++++++++++++++++++++++++
>  drivers/mtd/cfi_mtd.c                        |  2 +-
>  include/mtd/cfi_flash.h                      |  3 +
>  5 files changed, 184 insertions(+), 1 deletion(-)
>  create mode 100644 doc/device-tree-bindings/mtd/mtd-physmap.txt
>
> diff --git a/doc/device-tree-bindings/mtd/mtd-physmap.txt b/doc/device-tree-bindings/mtd/mtd-physmap.txt
> new file mode 100644
> index 0000000..4b8c489
> --- /dev/null
> +++ b/doc/device-tree-bindings/mtd/mtd-physmap.txt
> @@ -0,0 +1,88 @@
> +CFI or JEDEC memory-mapped NOR flash, MTD-RAM (NVRAM...)
> +
> +Flash chips (Memory Technology Devices) are often used for solid state
> +file systems on embedded devices.
> +
> + - compatible : should contain the specific model of mtd chip(s)
> +   used, if known, followed by either "cfi-flash", "jedec-flash",
> +   "mtd-ram" or "mtd-rom".
> + - reg : Address range(s) of the mtd chip(s)
> +   It's possible to (optionally) define multiple "reg" tuples so that
> +   non-identical chips can be described in one node.
> + - bank-width : Width (in bytes) of the bank.  Equal to the
> +   device width times the number of interleaved chips.
> + - device-width : (optional) Width of a single mtd chip.  If
> +   omitted, assumed to be equal to 'bank-width'.
> + - #address-cells, #size-cells : Must be present if the device has
> +   sub-nodes representing partitions (see below).  In this case
> +   both #address-cells and #size-cells must be equal to 1.
> + - no-unaligned-direct-access: boolean to disable the default direct
> +   mapping of the flash.
> +   On some platforms (e.g. MPC5200) a direct 1:1 mapping may cause
> +   problems with JFFS2 usage, as the local bus (LPB) doesn't support
> +   unaligned accesses as implemented in the JFFS2 code via memcpy().
> +   By defining "no-unaligned-direct-access", the flash will not be
> +   exposed directly to the MTD users (e.g. JFFS2) any more.
> + - linux,mtd-name: allow to specify the mtd name for retro capability with
> +   physmap-flash drivers as boot loader pass the mtd partition via the old
> +   device name physmap-flash.
> + - use-advanced-sector-protection: boolean to enable support for the
> +   advanced sector protection (Spansion: PPB - Persistent Protection
> +   Bits) locking.
> +
> +For JEDEC compatible devices, the following additional properties
> +are defined:
> +
> + - vendor-id : Contains the flash chip's vendor id (1 byte).
> + - device-id : Contains the flash chip's device id (1 byte).
> +
> +For ROM compatible devices (and ROM fallback from cfi-flash), the following
> +additional (optional) property is defined:
> +
> + - erase-size : The chip's physical erase block size in bytes.
> +
> +The device tree may optionally contain sub-nodes describing partitions of the
> +address space. See partition.txt for more detail.
> +
> +Example:
> +
> +       flash at ff000000 {
> +               compatible = "amd,am29lv128ml", "cfi-flash";
> +               reg = <ff000000 01000000>;
> +               bank-width = <4>;
> +               device-width = <1>;
> +               #address-cells = <1>;
> +               #size-cells = <1>;
> +               fs at 0 {
> +                       label = "fs";
> +                       reg = <0 f80000>;
> +               };
> +               firmware at f80000 {
> +                       label ="firmware";
> +                       reg = <f80000 80000>;
> +                       read-only;
> +               };
> +       };
> +
> +Here an example with multiple "reg" tuples:
> +
> +       flash at f0000000,0 {
> +               #address-cells = <1>;
> +               #size-cells = <1>;
> +               compatible = "intel,pc48f4400p0vb", "cfi-flash";
> +               reg = <0 0x00000000 0x02000000
> +                      0 0x02000000 0x02000000>;
> +               bank-width = <2>;
> +               partition at 0 {
> +                       label = "test-part1";
> +                       reg = <0 0x04000000>;
> +               };
> +       };
> +
> +An example using SRAM:
> +
> +       sram at 2,0 {
> +               compatible = "samsung,k6f1616u6a", "mtd-ram";
> +               reg = <2 0 0x00200000>;
> +               bank-width = <2>;
> +       };
> diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
> index 23dff48..367c4fe 100644
> --- a/drivers/mtd/Kconfig
> +++ b/drivers/mtd/Kconfig
> @@ -8,6 +8,17 @@ config MTD
>           flash, RAM and similar chips, often used for solid state file
>           systems on embedded devices.
>
> +config CFI_FLASH
> +       bool "Enable Driver Model for CFI Flash driver"
> +       depends on MTD
> +       help
> +         The Common Flash Interface specification was developed by Intel,
> +         AMD and other flash manufactures that provides a universal method

         flash manufacturers. It provides a universal method

> +         for probing the capabilities of flash devices. If you wish to
> +         support any device that is CFI-compliant, you need to enable this
> +         option. Visit <http://www.amd.com/products/nvd/overview/cfi.html>
> +         for more information on CFI.
> +
>  endmenu
>
>  source "drivers/mtd/nand/Kconfig"
> diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
> index fc7a878..5863699 100644
> --- a/drivers/mtd/cfi_flash.c
> +++ b/drivers/mtd/cfi_flash.c
> @@ -18,6 +18,9 @@
>  /* #define DEBUG       */
>
>  #include <common.h>
> +#include <dm.h>
> +#include <errno.h>
> +#include <fdt_support.h>
>  #include <asm/processor.h>
>  #include <asm/io.h>
>  #include <asm/byteorder.h>
> @@ -47,6 +50,8 @@
>   * reading and writing ... (yes there is such a Hardware).
>   */
>
> +DECLARE_GLOBAL_DATA_PTR;
> +
>  static uint flash_offset_cfi[2] = { FLASH_OFFSET_CFI, FLASH_OFFSET_CFI_ALT };
>  #ifdef CONFIG_FLASH_CFI_MTD
>  static uint flash_verbose = 1;
> @@ -87,10 +92,36 @@ static u16 cfi_flash_config_reg(int i)
>  int cfi_flash_num_flash_banks = CONFIG_SYS_MAX_FLASH_BANKS_DETECT;
>  #endif
>
> +#ifdef CONFIG_CFI_FLASH /* for driver model */
> +static void cfi_flash_init_dm(void)
> +{
> +       struct udevice *dev;
> +
> +       cfi_flash_num_flash_banks = 0;
> +       /*
> +        * The uclass_first_device() will probe the first device and
> +        * uclass_next_device() will probe the rest if they exist. So
> +        * that cfi_flash_probe() will get called assigning the base
> +        * addresses that are available.
> +        */
> +       for (uclass_first_device(UCLASS_MTD, &dev);
> +            dev;
> +            uclass_next_device(&dev)) {
> +       }

Why do you need to probe these before they are used? Also I think you
need error checking.

> +}
> +
> +static phys_addr_t cfi_flash_base[CFI_MAX_FLASH_BANKS];
> +
> +phys_addr_t cfi_flash_bank_addr(int i)
> +{
> +       return cfi_flash_base[i];
> +}
> +#else
>  __weak phys_addr_t cfi_flash_bank_addr(int i)
>  {
>         return ((phys_addr_t [])CONFIG_SYS_FLASH_BANKS_LIST)[i];
>  }
> +#endif
>
>  __weak unsigned long cfi_flash_bank_size(int i)
>  {
> @@ -2322,6 +2353,10 @@ unsigned long flash_init (void)
>         getenv_f("unlock", s, sizeof(s));
>  #endif
>
> +#ifdef CONFIG_CFI_FLASH /* for driver model */
> +       cfi_flash_init_dm();
> +#endif
> +
>         /* Init: no FLASHes known */
>         for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; ++i) {
>                 flash_info[i].flash_id = FLASH_UNKNOWN;
> @@ -2398,3 +2433,49 @@ unsigned long flash_init (void)
>
>         return (size);
>  }
> +
> +#ifdef CONFIG_CFI_FLASH /* for driver model */
> +static int cfi_flash_probe(struct udevice *dev)
> +{
> +       void *blob = (void *)gd->fdt_blob;
> +       int node = dev->of_offset;
> +       const fdt32_t *cell;
> +       phys_addr_t addr;
> +       int parent, addrc, sizec;
> +       int len, idx;
> +
> +       parent = fdt_parent_offset(blob, node);
> +       of_bus_default_count_cells(blob, parent, &addrc, &sizec);
> +       /* decode regs, there may be multiple reg tuples. */
> +       cell = fdt_getprop(blob, node, "reg", &len);
> +       if (!cell)
> +               return -ENOENT;
> +       idx = 0;
> +       len /= sizeof(fdt32_t);
> +       while (idx < len) {
> +               addr = fdt_translate_address((void *)blob,
> +                                            node, cell + idx);
> +               cfi_flash_base[cfi_flash_num_flash_banks++] = addr;
> +               idx += addrc + sizec;
> +       }
> +       gd->bd->bi_flashstart = cfi_flash_base[0];
> +#ifdef CONFIG_FLASH_CFI_MTD
> +       dev->uclass_priv = &cfi_mtd_info[0];

Could you put cfi_mtd_info in a struct and use auto-allocation to allocate it?

> +       cfi_mtd_info[0].dev = dev;
> +#endif
> +       return 0;
> +}
> +
> +static const struct udevice_id cfi_flash_ids[] = {
> +       { .compatible = "cfi-flash" },
> +       { .compatible = "jedec-flash" },
> +       {}
> +};
> +
> +U_BOOT_DRIVER(cfi_flash) = {
> +       .name   = "cfi_flash",
> +       .id     = UCLASS_MTD,
> +       .of_match = cfi_flash_ids,
> +       .probe = cfi_flash_probe,
> +};
> +#endif /* CONFIG_CFI_FLASH */
> diff --git a/drivers/mtd/cfi_mtd.c b/drivers/mtd/cfi_mtd.c
> index 709a486..dcd7ab0 100644
> --- a/drivers/mtd/cfi_mtd.c
> +++ b/drivers/mtd/cfi_mtd.c
> @@ -15,7 +15,7 @@
>  #include <linux/mtd/concat.h>
>  #include <mtd/cfi_flash.h>
>
> -static struct mtd_info cfi_mtd_info[CFI_MAX_FLASH_BANKS];
> +struct mtd_info cfi_mtd_info[CFI_MAX_FLASH_BANKS];
>  static char cfi_mtd_names[CFI_MAX_FLASH_BANKS][16];
>  #ifdef CONFIG_MTD_CONCAT
>  static char c_mtd_name[16];
> diff --git a/include/mtd/cfi_flash.h b/include/mtd/cfi_flash.h
> index 52572b9..c1632f3 100644
> --- a/include/mtd/cfi_flash.h
> +++ b/include/mtd/cfi_flash.h
> @@ -8,6 +8,8 @@
>  #ifndef __CFI_FLASH_H__
>  #define __CFI_FLASH_H__
>
> +#include <linux/mtd/mtd.h>
> +
>  #define FLASH_CMD_CFI                  0x98
>  #define FLASH_CMD_READ_ID              0x90
>  #define FLASH_CMD_RESET                        0xff
> @@ -164,6 +166,7 @@ extern int cfi_flash_num_flash_banks;
>  #else
>  #define CFI_MAX_FLASH_BANKS    CONFIG_SYS_MAX_FLASH_BANKS
>  #endif
> +extern struct mtd_info cfi_mtd_info[];
>
>  void flash_write_cmd(flash_info_t * info, flash_sect_t sect,
>                      uint offset, u32 cmd);
> --
> 2.5.0
>

Regards,
Simon


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