From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vignesh R Subject: [PATCH v4 4/6] mtd: spi-nor: cadence-quadspi: Add support to enable loop-back clock circuit Date: Tue, 3 Oct 2017 10:49:23 +0530 Message-ID: <20171003051925.8821-5-vigneshr@ti.com> References: <20171003051925.8821-1-vigneshr@ti.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20171003051925.8821-1-vigneshr-l0cyMroinI0@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Marek Vasut , Cyrille Pitchen Cc: David Woodhouse , Brian Norris , Boris Brezillon , Rob Herring , linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Vignesh R , linux-arm-kernel List-Id: devicetree@vger.kernel.org Cadence QSPI IP has a adapted loop-back 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 loop-back circuit using QSPI return clock helps to increase data valid window. Based on DT parameter cdns,rclk-en enable adapted loop-back 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 --- drivers/mtd/spi-nor/cadence-quadspi.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c index 5cd5d6f7303f..d9629e8f4798 100644 --- a/drivers/mtd/spi-nor/cadence-quadspi.c +++ b/drivers/mtd/spi-nor/cadence-quadspi.c @@ -78,6 +78,7 @@ 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]; @@ -788,7 +789,7 @@ 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; @@ -852,7 +853,8 @@ 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) @@ -1049,6 +1051,8 @@ 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; } -- 2.14.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html