On 12/05/2016 11:46 AM, Phil Edworthy wrote:
Hi Jagan,
On 05 December 2016 10:42, Jagan Teki wrote:
On Mon, Dec 5, 2016 at 11:31 AM, Phil Edworthy phil.edworthy@renesas.com wrote:
HI Jagan,
On 05 December 2016 10:26, Jagan Teki wrote:
On Mon, Dec 5, 2016 at 11:09 AM, Phil Edworthy phil.edworthy@renesas.com wrote:
Hi Jagan,
On 02 December 2016 14:23, Jagan Teki wrote:
On Tue, Nov 29, 2016 at 6:28 PM, Phil Edworthy phil.edworthy@renesas.com wrote: > Introduce a new DT property to specify whether the QSPI Controller > samples the data on a rising edge. The default is falling edge. > Some versions of the QSPI Controller do not implement this bit, in > which case the property should be omitted. > > Signed-off-by: Phil Edworthy phil.edworthy@renesas.com > --- > v3: > - Patch split so this one only has code related to the subject. > - Commit message updated. > v2: > - Change name of DT prop and provide details of what it does. > Whilst at it, move the code to read the "sram-size" property > into the other code that reads properties from the node, rather > than the SF subnode. > > Also change the code to use a bool for the bypass arg. > --- > doc/device-tree-bindings/spi/spi-cadence.txt | 2 ++ > drivers/spi/cadence_qspi.c | 10 +++++++--- > drivers/spi/cadence_qspi.h | 3 ++- > drivers/spi/cadence_qspi_apb.c | 8 +++++++- > 4 files changed, 18 insertions(+), 5 deletions(-) > > diff --git a/doc/device-tree-bindings/spi/spi-cadence.txt b/doc/device-
tree-
bindings/spi/spi-cadence.txt > index c1e2233..94c800b 100644 > --- a/doc/device-tree-bindings/spi/spi-cadence.txt > +++ b/doc/device-tree-bindings/spi/spi-cadence.txt > @@ -26,3 +26,5 @@ connected flash properties > select (n_ss_out). > - tslch-ns : Delay in master reference clocks between setting > n_ss_out low and first bit transfer > +- sample-edge-rising : Data outputs from flash memory will be sampled
on
the > + rising edge. Default is falling edge.
Code look reasonable, but how Linux handling this with the same dt property, any idea? I couldn't find it either.
The Linux driver does not yet have this property. Is there a policy to add new props to Linux first?
If the same/equal code used in Linux better to have the same property instead of another name used in U-boot?
Of course, but I cannot see this in Linux: https://git.kernel.org/cgit/linux/kernel/git/next/linux-
next.git/tree/Documentation/devicetree/bindings/spi/spi-cadence.txt
Yeah, I saw this. Do you have any idea how Linux handling this sample edge?
The same way U-Boot currently handles it, i.e. it does nothing with this. Intel/Altera (Chin Liang) said that they do not have this bit in their version of the Cadence QSPI Controller.
We are using a later version that has had this bit added.
You were looking at the wrong bindings: https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/tree/Docume...
but yes, Linux does not do support the data edge toggling. I think there was another QSPI patch in Linux which tried adding such property, so check linux-mtd for it. Generic one would be great.
And no, there is no policy for pushing new props to linux first. New DT props should ideally get approved via devicetree@vger though, but that's about it. Also, while I tried backporting the Linux CQSPI driver to U-Boot, but unfortunately, it turned out to be extremely difficult due significant differences between the Linux and U-Boot SPI NOR framework.