Patch "mtd: spi-nor: cadence-quadspi: add a delay in write sequence" has been added to the 4.14-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    mtd: spi-nor: cadence-quadspi: add a delay in write sequence

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mtd-spi-nor-cadence-quadspi-add-a-delay-in-write-sequence.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From foo@baz Mon 11 Nov 2019 10:07:22 AM CET
From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Date: Thu,  5 Sep 2019 10:17:49 -0600
Subject: mtd: spi-nor: cadence-quadspi: add a delay in write sequence
To: stable@xxxxxxxxxxxxxxx
Cc: linux-usb@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, linux-pm@xxxxxxxxxxxxxxx, dri-devel@xxxxxxxxxxxxxxxxxxxxx, linux-omap@xxxxxxxxxxxxxxx, linux-i2c@xxxxxxxxxxxxxxx, linux-pci@xxxxxxxxxxxxxxx, linux-mtd@xxxxxxxxxxxxxxxxxxx
Message-ID: <20190905161759.28036-9-mathieu.poirier@xxxxxxxxxx>

From: Vignesh R <vigneshr@xxxxxx>

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 <vigneshr@xxxxxx>
Acked-by: Marek Vasut <marek.vasut@xxxxxxxxx>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/mtd/spi-nor/cadence-quadspi.c |   27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

--- 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(
 	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_d
 	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_d
 	}
 
 	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__de
 #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 */ }
 };
 


Patches currently in stable-queue which might be from mathieu.poirier@xxxxxxxxxx are

queue-4.14/mailbox-reset-txdone_method-txdone_by_poll-if-client-knows_txdone.patch
queue-4.14/mtd-spi-nor-cadence-quadspi-add-a-delay-in-write-sequence.patch
queue-4.14/misc-pci_endpoint_test-fix-bug_on-error-during-pci_disable_msi.patch
queue-4.14/asoc-tlv320dac31xx-mark-expected-switch-fall-through.patch
queue-4.14/pci-dra7xx-add-shutdown-handler-to-cleanly-turn-off-clocks.patch
queue-4.14/asoc-tlv320aic31xx-handle-inverted-bclk-in-non-dsp-modes.patch
queue-4.14/mtd-spi-nor-enable-4b-opcodes-for-mx66l51235l.patch
queue-4.14/cpufreq-ti-cpufreq-add-missing-of_node_put.patch
queue-4.14/asoc-davinci-kill-bug_on-usage.patch
queue-4.14/mfd-palmas-assign-the-right-powerhold-mask-for-tps65917.patch
queue-4.14/asoc-davinci-mcasp-fix-an-error-handling-path-in-davinci_mcasp_probe.patch
queue-4.14/misc-pci_endpoint_test-prevent-some-integer-overflows.patch
queue-4.14/asoc-davinci-mcasp-handle-return-value-of-devm_kasprintf.patch
queue-4.14/i2c-omap-trigger-bus-recovery-in-lockup-case.patch
queue-4.14/usb-dwc3-allow-disabling-of-metastability-workaround.patch

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