From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Poirier Subject: [BACKPORT 4.14.y 08/18] mtd: spi-nor: cadence-quadspi: add a delay in write sequence Date: Thu, 5 Sep 2019 10:17:49 -0600 Message-ID: <20190905161759.28036-9-mathieu.poirier@linaro.org> References: <20190905161759.28036-1-mathieu.poirier@linaro.org> Return-path: In-Reply-To: <20190905161759.28036-1-mathieu.poirier@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: stable@vger.kernel.org Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-omap@vger.kernel.org, linux-i2c@vger.kernel.org, linux-pci@vger.kernel.org, linux-mtd@lists.infradead.org List-Id: linux-i2c@vger.kernel.org From: Vignesh R commit 61dc8493bae9ba82a1c72edbc6c6065f6a94456a upstream As per 66AK2G02 TRM[1] SPRUHY8F section 11.15.5.3 Indirect Access Controller programming sequence, a delay equal to couple of QSPI master clock(~5ns) is required after setting CQSPI_REG_INDIRECTWR_START bit and writing data to the flash. Introduce a quirk flag CQSPI_NEEDS_WR_DELAY to handle this and set this flag for TI 66AK2G SoC. [1]http://www.ti.com/lit/ug/spruhy8f/spruhy8f.pdf Signed-off-by: Vignesh R Acked-by: Marek Vasut Signed-off-by: Cyrille Pitchen Signed-off-by: Mathieu Poirier --- drivers/mtd/spi-nor/cadence-quadspi.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c index f22dd34f4f83..ff4edf4bb23c 100644 --- a/drivers/mtd/spi-nor/cadence-quadspi.c +++ b/drivers/mtd/spi-nor/cadence-quadspi.c @@ -38,6 +38,9 @@ #define CQSPI_NAME "cadence-qspi" #define CQSPI_MAX_CHIPSELECT 16 +/* Quirks */ +#define CQSPI_NEEDS_WR_DELAY BIT(0) + struct cqspi_st; struct cqspi_flash_pdata { @@ -76,6 +79,7 @@ struct cqspi_st { u32 fifo_depth; u32 fifo_width; u32 trigger_address; + u32 wr_delay; struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT]; }; @@ -623,6 +627,15 @@ static int cqspi_indirect_write_execute(struct spi_nor *nor, reinit_completion(&cqspi->transfer_complete); writel(CQSPI_REG_INDIRECTWR_START_MASK, reg_base + CQSPI_REG_INDIRECTWR); + /* + * As per 66AK2G02 TRM SPRUHY8F section 11.15.5.3 Indirect Access + * Controller programming sequence, couple of cycles of + * QSPI_REF_CLK delay is required for the above bit to + * be internally synchronized by the QSPI module. Provide 5 + * cycles of delay. + */ + if (cqspi->wr_delay) + ndelay(cqspi->wr_delay); while (remaining > 0) { size_t write_words, mod_bytes; @@ -1184,6 +1197,7 @@ static int cqspi_probe(struct platform_device *pdev) struct cqspi_st *cqspi; struct resource *res; struct resource *res_ahb; + unsigned long data; int ret; int irq; @@ -1241,6 +1255,10 @@ static int cqspi_probe(struct platform_device *pdev) } cqspi->master_ref_clk_hz = clk_get_rate(cqspi->clk); + data = (unsigned long)of_device_get_match_data(dev); + if (data & CQSPI_NEEDS_WR_DELAY) + cqspi->wr_delay = 5 * DIV_ROUND_UP(NSEC_PER_SEC, + cqspi->master_ref_clk_hz); ret = devm_request_irq(dev, irq, cqspi_irq_handler, 0, pdev->name, cqspi); @@ -1312,7 +1330,14 @@ static const struct dev_pm_ops cqspi__dev_pm_ops = { #endif static const struct of_device_id cqspi_dt_ids[] = { - {.compatible = "cdns,qspi-nor",}, + { + .compatible = "cdns,qspi-nor", + .data = (void *)0, + }, + { + .compatible = "ti,k2g-qspi", + .data = (void *)CQSPI_NEEDS_WR_DELAY, + }, { /* end of table */ } }; -- 2.17.1