47 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			47 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From 08922f644878c9163ada8df3ef9def89be1d5e90 Mon Sep 17 00:00:00 2001
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| From: Vignesh R <vigneshr@ti.com>
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| Date: Tue, 29 Mar 2016 11:16:17 +0530
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| Subject: [PATCH] mtd: devices: m25p80: add support for mmap read request
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| 
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| Certain SPI controllers may provide accelerated hardware interface to
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| read from m25p80 type flash devices in order to provide better read
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| performance. SPI core supports such devices with spi_flash_read() API.
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| Call spi_flash_read(), if supported, to make use of such interface.
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| 
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| Signed-off-by: Vignesh R <vigneshr@ti.com>
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| [Brian: add memset()]
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| Signed-off-by: Brian Norris <computersforpeace@gmail.com>
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| ---
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| 
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| --- a/drivers/mtd/devices/m25p80.c
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| +++ b/drivers/mtd/devices/m25p80.c
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| @@ -131,6 +131,28 @@ static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
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|  	/* convert the dummy cycles to the number of bytes */
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|  	dummy /= 8;
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|  
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| +	if (spi_flash_read_supported(spi)) {
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| +		struct spi_flash_read_message msg;
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| +		int ret;
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| +
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| +		memset(&msg, 0, sizeof(msg));
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| +
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| +		msg.buf = buf;
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| +		msg.from = from;
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| +		msg.len = len;
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| +		msg.read_opcode = nor->read_opcode;
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| +		msg.addr_width = nor->addr_width;
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| +		msg.dummy_bytes = dummy;
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| +		/* TODO: Support other combinations */
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| +		msg.opcode_nbits = SPI_NBITS_SINGLE;
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| +		msg.addr_nbits = SPI_NBITS_SINGLE;
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| +		msg.data_nbits = m25p80_rx_nbits(nor);
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| +
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| +		ret = spi_flash_read(spi, &msg);
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| +		*retlen = msg.retlen;
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| +		return ret;
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| +	}
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| +
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|  	spi_message_init(&m);
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|  	memset(t, 0, (sizeof t));
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|  
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