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	This patch adds support of NOR cape[1] for both Beaglebone (white) and Beaglebone(Black) boards. NOR Flash on this cape is connected to GPMC chip-select[0] and accesses as external memory-mapped device. This cape has 128Mbits(16MBytes), x16, CFI compatible NOR Flash device. As GPMC chip-select[0] can be shared by multiple capes so NOR profile is not enabled by default in boards.cfg. Following changes are required to enable NOR cape detection when building am335x_boneblack board profile. Signed-off-by: Tom Rini <trini@ti.com>
		
			
				
	
	
		
			43 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			43 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
The common CFI driver provides this weak default implementation for
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flash_cmd_reset():
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void __flash_cmd_reset(flash_info_t *info)
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{
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	/*
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	 * We do not yet know what kind of commandset to use, so we issue
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	 * the reset command in both Intel and AMD variants, in the hope
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	 * that AMD flash roms ignore the Intel command.
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	 */
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	flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
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	flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
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}
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void flash_cmd_reset(flash_info_t *info)
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	__attribute__((weak,alias("__flash_cmd_reset")));
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Some flash chips seems to have trouble with this reset sequence. In this case
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the board specific code can override this weak default version with a board
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specific function. For example the digsy_mtc board equipped with the M29W128GH
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from Numonyx needs this version to function properly:
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void flash_cmd_reset(flash_info_t *info)
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{
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	flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
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}
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see also:
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http://www.mail-archive.com/u-boot@lists.denx.de/msg24368.html
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Config Option
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  CONFIG_SYS_MAX_FLASH_SECT: Number of sectors available on Flash device
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  CONFIG_SYS_FLASH_CFI_WIDTH: Data-width of the flash device
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  CONFIG_CMD_FLASH: Enables Flash command library
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  CONFIG_FLASH_CFI_DRIVER: Enables CFI Flash driver
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  CONFIG_FLASH_CFI_MTD: Enables MTD frame work for NOR Flash devices
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