From 7513e006c64fbe2f43aef2139c8c1f2b1a9cb6b9 Mon Sep 17 00:00:00 2001 From: Michael Hennerich Date: Mon, 6 Apr 2009 19:00:32 -0700 Subject: [PATCH] Blackfin SPI Driver: Fix erroneous SPI Clock divisor calculation Fix erroneous SPI Clock divisor calculation. Make sure SPI_BAUD is always >= 2. Writing a value of 0 or 1 to the SPI_BAUD register disables the serial clock. Signed-off-by: Michael Hennerich Signed-off-by: Bryan Wu Acked-by: David Brownell Cc: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/blackfin/include/asm/bfin5xx_spi.h | 2 ++ drivers/spi/spi_bfin5xx.c | 3 +++ 2 files changed, 5 insertions(+) diff --git a/arch/blackfin/include/asm/bfin5xx_spi.h b/arch/blackfin/include/asm/bfin5xx_spi.h index 0292d58f936..ea2d24af954 100644 --- a/arch/blackfin/include/asm/bfin5xx_spi.h +++ b/arch/blackfin/include/asm/bfin5xx_spi.h @@ -11,6 +11,8 @@ #ifndef _SPI_CHANNEL_H_ #define _SPI_CHANNEL_H_ +#define MIN_SPI_BAUD_VAL 2 + #define SPI_READ 0 #define SPI_WRITE 1 diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index e440718b320..a3e06283f74 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -158,6 +158,9 @@ static u16 hz_to_spi_baud(u32 speed_hz) if ((sclk % (2 * speed_hz)) > 0) spi_baud++; + if (spi_baud < MIN_SPI_BAUD_VAL) + spi_baud = MIN_SPI_BAUD_VAL; + return spi_baud; } -- 2.41.0