| Message ID | 20170801045434.8733-3-vigneshr@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Aug 01, 2017 at 10:24:29AM +0530, Vignesh R wrote: > Cadence QSPI IP has a adapted loopback circuit which can be enabled by > setting BYPASS field to 0 in READCAPTURE register. It enables use of > QSPI return clock to latch the data rather than the internal QSPI > reference clock. For high speed operations, adapted loopback circuit > using QSPI return clock helps to increase data valid window. > > Add DT parameter cdns,rclk-en to help enable adapted loopback circuit > for boards which do have QSPI return clock provided. > This patch also modifies cqspi_readdata_capture() function's bypass > parameter to bool to match how its used in the function. > > Signed-off-by: Vignesh R <vigneshr@ti.com> > --- > Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 3 +++ > drivers/mtd/spi-nor/cadence-quadspi.c | 8 ++++++-- > 2 files changed, 9 insertions(+), 2 deletions(-) Please separate bindings to a separate patch or patches. Rob
On Thursday 10 August 2017 05:40 AM, Rob Herring wrote: > On Tue, Aug 01, 2017 at 10:24:29AM +0530, Vignesh R wrote: >> Cadence QSPI IP has a adapted loopback circuit which can be enabled by >> setting BYPASS field to 0 in READCAPTURE register. It enables use of >> QSPI return clock to latch the data rather than the internal QSPI >> reference clock. For high speed operations, adapted loopback circuit >> using QSPI return clock helps to increase data valid window. >> >> Add DT parameter cdns,rclk-en to help enable adapted loopback circuit >> for boards which do have QSPI return clock provided. >> This patch also modifies cqspi_readdata_capture() function's bypass >> parameter to bool to match how its used in the function. >> >> Signed-off-by: Vignesh R <vigneshr@ti.com> >> --- >> Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 3 +++ >> drivers/mtd/spi-nor/cadence-quadspi.c | 8 ++++++-- >> 2 files changed, 9 insertions(+), 2 deletions(-) > > Please separate bindings to a separate patch or patches. > Ok, Will do that in v2.
diff --git a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt index fdd511a83511..6cc7d58ce7f6 100644 --- a/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt +++ b/Documentation/devicetree/bindings/mtd/cadence-quadspi.txt @@ -15,6 +15,9 @@ Required properties: Optional properties: - cdns,is-decoded-cs : Flag to indicate whether decoder is used or not. +- cdns,rclk-en : Flag to indicate that QSPI return clock is used to latch + the read data rather than the QSPI clock. Make sure that QSPI return + clock is populated on the board before using this property. Optional subnodes: Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c index 94571590371d..297c86a2d4a7 100644 --- a/drivers/mtd/spi-nor/cadence-quadspi.c +++ b/drivers/mtd/spi-nor/cadence-quadspi.c @@ -75,6 +75,7 @@ struct cqspi_st { bool is_decoded_cs; u32 fifo_depth; u32 fifo_width; + bool rclk_en; u32 trigger_address; u32 wr_delay; struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT]; @@ -784,7 +785,7 @@ static void cqspi_config_baudrate_div(struct cqspi_st *cqspi) } static void cqspi_readdata_capture(struct cqspi_st *cqspi, - const unsigned int bypass, + const bool bypass, const unsigned int delay) { void __iomem *reg_base = cqspi->iobase; @@ -848,7 +849,8 @@ static void cqspi_configure(struct spi_nor *nor) cqspi->sclk = sclk; cqspi_config_baudrate_div(cqspi); cqspi_delay(nor); - cqspi_readdata_capture(cqspi, 1, f_pdata->read_delay); + cqspi_readdata_capture(cqspi, !cqspi->rclk_en, + f_pdata->read_delay); } if (switch_cs || switch_ck) @@ -1045,6 +1047,8 @@ static int cqspi_of_get_pdata(struct platform_device *pdev) return -ENXIO; } + cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en"); + return 0; }
Cadence QSPI IP has a adapted loopback circuit which can be enabled by setting BYPASS field to 0 in READCAPTURE register. It enables use of QSPI return clock to latch the data rather than the internal QSPI reference clock. For high speed operations, adapted loopback circuit using QSPI return clock helps to increase data valid window. Add DT parameter cdns,rclk-en to help enable adapted loopback circuit for boards which do have QSPI return clock provided. This patch also modifies cqspi_readdata_capture() function's bypass parameter to bool to match how its used in the function. Signed-off-by: Vignesh R <vigneshr@ti.com> --- Documentation/devicetree/bindings/mtd/cadence-quadspi.txt | 3 +++ drivers/mtd/spi-nor/cadence-quadspi.c | 8 ++++++-- 2 files changed, 9 insertions(+), 2 deletions(-)