> -----Original Message----- > From: Prafulla Wadaskar > Sent: 16 August 2012 09:44 > To: 'Valentin Longchamp'; u-boot@lists.denx.de > Cc: Holger Brunck > Subject: RE: [PATCH v2] kw_spi: fix clock prescaler computation > > > > > -----Original Message----- > > From: Valentin Longchamp [mailto:valentin.longch...@keymile.com] > > Sent: 15 August 2012 21:02 > > To: u-boot@lists.denx.de > > Cc: Valentin Longchamp; Holger Brunck; Prafulla Wadaskar > > Subject: [PATCH v2] kw_spi: fix clock prescaler computation > > > > The computation was not correct with low clock values: setting a > 1MHz > > clock would result in an overlap that would then configure a 25Mhz > > clock. > > > > This patch implements a correct computation method according to the > > kirkwood functionnal spec. table 600 (Serial Memory Interface > > Configuration Register). > > > > Signed-off-by: Valentin Longchamp <valentin.longch...@keymile.com> > > cc: Holger Brunck <holger.bru...@keymile.com> > > cc: Prafulla Wadaskar <prafu...@marvell.com> > > --- > > changes for v2: > > - table nb in commit message > > > > > > arch/arm/include/asm/arch-kirkwood/spi.h | 1 + > > drivers/spi/kirkwood_spi.c | 5 +++-- > > 2 files changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm/include/asm/arch-kirkwood/spi.h > > b/arch/arm/include/asm/arch-kirkwood/spi.h > > index 1d5043f..5a38dc5 100644 > > --- a/arch/arm/include/asm/arch-kirkwood/spi.h > > +++ b/arch/arm/include/asm/arch-kirkwood/spi.h > > @@ -38,6 +38,7 @@ struct kwspi_registers { > > }; > > > > #define KWSPI_CLKPRESCL_MASK 0x1f > > +#define KWSPI_CLKPRESCL_MIN 0x12 > > #define KWSPI_CSN_ACT 1 /* Activates serial memory interface > > */ > > #define KWSPI_SMEMRDY (1 << 1) /* SerMem Data xfer ready */ > > #define KWSPI_IRQUNMASK 1 /* unmask SPI interrupt */ > > diff --git a/drivers/spi/kirkwood_spi.c b/drivers/spi/kirkwood_spi.c > > index ee14669..9b3f6a4 100644 > > --- a/drivers/spi/kirkwood_spi.c > > +++ b/drivers/spi/kirkwood_spi.c > > @@ -57,8 +57,9 @@ struct spi_slave *spi_setup_slave(unsigned int > bus, > > unsigned int cs, > > writel(~KWSPI_CSN_ACT | KWSPI_SMEMRDY, &spireg->ctrl); > > > > /* calculate spi clock prescaller using max_hz */ > > - data = ((CONFIG_SYS_TCLK / 2) / max_hz) & KWSPI_CLKPRESCL_MASK; > > - data |= 0x10; > > + data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10; > > + data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data; > > + data = data > KWSPI_CLKPRESCL_MASK ? KWSPI_CLKPRESCL_MASK : data; > > > > /* program spi clock prescaller using max_hz */ > > writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg); > > -- > > Acked-by: Prafulla Wadaskar <prafu...@marvell.com> > Will pull this soon.
Applied to u-boot-marvell.git to master branch by resolving merge conflict Regards... Prafulla . . . _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
