Re: [U-Boot] [PATCH v3 2/3] cfi_flash: convert to driver model

Hi Thomas,

On 30.10.2015 14:33, Thomas Chou wrote:

Convert cfi flash to driver model.

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. v3 change to MTD uclass.

doc/device-tree-bindings/mtd/mtd-physmap.txt | 88 ++++++++++++++++++++++++++++ drivers/mtd/Kconfig | 11 ++++ drivers/mtd/cfi_flash.c | 69 ++++++++++++++++++++++ drivers/mtd/cfi_mtd.c | 2 +- include/mtd/cfi_flash.h | 3 + 5 files changed, 172 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@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";
  

• 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>;
  

• };

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
  

•  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..a439d8b 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 +92,19 @@ 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 +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) { @@ -2315,6 +2329,7 @@ unsigned long flash_init (void) { unsigned long size = 0; int i;

• struct udevice *dev;

I'm seeing this warning while compiling for some powerpc boards (e.g. canyonlands):

drivers/mtd/cfi_flash.c: In function 'flash_init': drivers/mtd/cfi_flash.c:2332:18: warning: unused variable 'dev' [-Wunused-variable]

Perhaps an "__maybe_unused" needed here.

#ifdef CONFIG_SYS_FLASH_PROTECTION /* read environment from EEPROM */ @@ -2322,6 +2337,14 @@ unsigned long flash_init (void) getenv_f("unlock", s, sizeof(s)); #endif

+#ifdef CONFIG_CFI_FLASH /* for driver model */

• cfi_flash_num_flash_banks = 0;
• /* probe every MTD device */
• for (uclass_first_device(UCLASS_MTD, &dev);

•     dev;
  

•     uclass_next_device(&dev)) {
  

• }

+#endif

What is this loop above exactly doing?

Thanks, Stefan