Re: [U-Boot] [PATCH v2] dm: implement a cfi flash uclass

+Simon,

Hi Thomas,

On Sun, Oct 11, 2015 at 3:30 PM, Thomas Chou thomas@wytron.com.tw wrote:

Implement a cfi flash uclass to work with drivers/mtd/cfi-flash.c. The flash base address is extracted from device tree, and passed to cfi_flash_bank_addr().

The current code supports only one bank. It should be extended to support multiple banks by decoding multiple "reg" tuples, eg, reg = <0 0x00000000 0x02000000 0 0x02000000 0x02000000>;

Signed-off-by: Thomas Chou thomas@wytron.com.tw

v2 add dts binding. add more help to Kconfig. move struct platdata to top of file as Simon suggested.

common/board_r.c | 3 + configs/nios2-generic_defconfig | 1 + doc/device-tree-bindings/mtd/mtd-physmap.txt | 88 ++++++++++++++++++++++++++++ drivers/mtd/Kconfig | 16 +++++ drivers/mtd/Makefile | 1 + drivers/mtd/cfi-flash-uclass.c | 70 ++++++++++++++++++++++ drivers/mtd/cfi_flash.c | 18 ++++++ include/cfi-flash.h | 27 +++++++++ include/dm/uclass-id.h | 1 + 9 files changed, 225 insertions(+) create mode 100644 doc/device-tree-bindings/mtd/mtd-physmap.txt create mode 100644 drivers/mtd/cfi-flash-uclass.c create mode 100644 include/cfi-flash.h

diff --git a/common/board_r.c b/common/board_r.c index a4facf8..fceaea6 100644 --- a/common/board_r.c +++ b/common/board_r.c @@ -38,6 +38,7 @@ #include <miiphy.h> #endif #include <mmc.h> +#include <mtd/cfi_flash.h> #include <nand.h> #include <onenand_uboot.h> #include <scsi.h> @@ -348,6 +349,8 @@ static int initr_flash(void) /* update start of FLASH memory */ #ifdef CONFIG_SYS_FLASH_BASE bd->bi_flashstart = CONFIG_SYS_FLASH_BASE; +#else

•   bd->bi_flashstart = cfi_flash_bank_addr(0);
  

#endif /* size of FLASH memory (final value) */ bd->bi_flashsize = flash_size; diff --git a/configs/nios2-generic_defconfig b/configs/nios2-generic_defconfig index 3d404b2..7b504ba 100644 --- a/configs/nios2-generic_defconfig +++ b/configs/nios2-generic_defconfig @@ -18,6 +18,7 @@ CONFIG_NET_RANDOM_ETHADDR=y CONFIG_ALTERA_PIO=y CONFIG_MISC=y CONFIG_ALTERA_SYSID=y +CONFIG_CFI_FLASH=y CONFIG_ALTERA_JTAG_UART=y CONFIG_ALTERA_JTAG_UART_BYPASS=y CONFIG_TIMER=y 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..a04d6e8 --- /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@ff000000 {
  

•           compatible = "amd,am29lv128ml", "cfi-flash";
  

•           reg = <ff000000 01000000>;
  

•           bank-width = <4>;
  

•           device-width = <1>;
  

•           #address-cells = <1>;
  

•           #size-cells = <1>;
  

•           fs@0 {
  

•                   label = "fs";
  

•                   reg = <0 f80000>;
  

•           };
  

•           firmware@f80000 {
  

•                   label ="firmware";
  

•                   reg = <f80000 80000>;
  

•                   read-only;
  

•           };
  

•   };
  

+Here an example with multiple "reg" tuples:

•   flash@f0000000,0 {
  

•           #address-cells = <1>;
  

•           #size-cells = <1>;
  

•           compatible = "intel,PC48F4400P0VB", "cfi-flash";
  

PC48F4400P0VB should be lower cases

•           reg = <0 0x00000000 0x02000000
  

•                  0 0x02000000 0x02000000>;
  

•           bank-width = <2>;
  

•           partition@0 {
  

•                   label = "test-part1";
  

•                   reg = <0 0x04000000>;
  

•           };
  

•   };
  

+An example using SRAM:

•   sram@2,0 {
  

•           compatible = "samsung,k6f1616u6a", "mtd-ram";
  

•           reg = <2 0 0x00200000>;
  

•           bank-width = <2>;
  

•   };
  

By looking at the implementation, is it really necessary to add a new uclass for cfi-flash, given we only need get the flash base address? There are no cfi-flash specific ops defined. Why not just read its base address from device tree?

[snip]

Regards, Bin