From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vignesh R Subject: Re: [PATCH] ARM: dts: dra7: Support QSPI MODE-0 operation at 64MHz Date: Mon, 29 Feb 2016 17:22:45 +0530 Message-ID: <56D4310D.5020608@ti.com> References: <1456375652-14071-1-git-send-email-vigneshr@ti.com> <20160226191342.GF13417@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160226191342.GF13417@atomide.com> Sender: linux-kernel-owner@vger.kernel.org To: Tony Lindgren Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Russell King , "linux-omap@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" List-Id: linux-omap@vger.kernel.org Hi, On 02/27/2016 12:43 AM, Tony Lindgren wrote: > Hi, > > * Vignesh R [160224 20:49]: >> According to Data Manual(SPRS915P) of AM57x, TI QSPI controller on >> DRA74(rev 1.1+) can support up to 64MHz in MODE-0, whereas MODE-3 is >> limited to 48MHz. Hence, switch to MODE-0 for better throughput. >> >> Signed-off-by: Vignesh R >> --- >> arch/arm/boot/dts/dra7-evm.dts | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/boot/dts/dra7-evm.dts b/arch/arm/boot/dts/dra7-evm.dts >> index cfc24e52244e..15f10bdc8c31 100644 >> --- a/arch/arm/boot/dts/dra7-evm.dts >> +++ b/arch/arm/boot/dts/dra7-evm.dts >> @@ -653,15 +653,13 @@ >> pinctrl-names = "default"; >> pinctrl-0 = <&qspi1_pins>; >> >> - spi-max-frequency = <48000000>; >> + spi-max-frequency = <64000000>; >> m25p80@0 { >> compatible = "s25fl256s1"; >> - spi-max-frequency = <48000000>; >> + spi-max-frequency = <64000000>; >> reg = <0>; >> spi-tx-bus-width = <1>; >> spi-rx-bus-width = <4>; >> - spi-cpol; >> - spi-cpha; >> #address-cells = <1>; >> #size-cells = <1>; >> > > Do we have any earlier pre DRA74(rev 1.1)versions in use too? Yes, there are pre 1.1 boards (production boards are all rev 1.1+), but QSPI is broken on them due to erratas (even w/o this patch). > > What about the spi-cpol and spi-cpha changes? Those should be > at least documented? > Ok, I will add a NOTE in the documentation saying "spi-cpol" and "spi-cpha" are not supported by ti-qspi in Documentation/devicetree/bindings/spi/ti_qspi.txt. -- Regards Vignesh From mboxrd@z Thu Jan 1 00:00:00 1970 From: vigneshr@ti.com (Vignesh R) Date: Mon, 29 Feb 2016 17:22:45 +0530 Subject: [PATCH] ARM: dts: dra7: Support QSPI MODE-0 operation at 64MHz In-Reply-To: <20160226191342.GF13417@atomide.com> References: <1456375652-14071-1-git-send-email-vigneshr@ti.com> <20160226191342.GF13417@atomide.com> Message-ID: <56D4310D.5020608@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On 02/27/2016 12:43 AM, Tony Lindgren wrote: > Hi, > > * Vignesh R [160224 20:49]: >> According to Data Manual(SPRS915P) of AM57x, TI QSPI controller on >> DRA74(rev 1.1+) can support up to 64MHz in MODE-0, whereas MODE-3 is >> limited to 48MHz. Hence, switch to MODE-0 for better throughput. >> >> Signed-off-by: Vignesh R >> --- >> arch/arm/boot/dts/dra7-evm.dts | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/boot/dts/dra7-evm.dts b/arch/arm/boot/dts/dra7-evm.dts >> index cfc24e52244e..15f10bdc8c31 100644 >> --- a/arch/arm/boot/dts/dra7-evm.dts >> +++ b/arch/arm/boot/dts/dra7-evm.dts >> @@ -653,15 +653,13 @@ >> pinctrl-names = "default"; >> pinctrl-0 = <&qspi1_pins>; >> >> - spi-max-frequency = <48000000>; >> + spi-max-frequency = <64000000>; >> m25p80 at 0 { >> compatible = "s25fl256s1"; >> - spi-max-frequency = <48000000>; >> + spi-max-frequency = <64000000>; >> reg = <0>; >> spi-tx-bus-width = <1>; >> spi-rx-bus-width = <4>; >> - spi-cpol; >> - spi-cpha; >> #address-cells = <1>; >> #size-cells = <1>; >> > > Do we have any earlier pre DRA74(rev 1.1)versions in use too? Yes, there are pre 1.1 boards (production boards are all rev 1.1+), but QSPI is broken on them due to erratas (even w/o this patch). > > What about the spi-cpol and spi-cpha changes? Those should be > at least documented? > Ok, I will add a NOTE in the documentation saying "spi-cpol" and "spi-cpha" are not supported by ti-qspi in Documentation/devicetree/bindings/spi/ti_qspi.txt. -- Regards Vignesh