From:   Dhruva Gole <d-gole@ti.com>
To:     Mark Brown <broonie@kernel.org>
CC:     <linux-spi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Vaishnav Achath <vaishnav.a@ti.com>,
        Dhruva Gole <d-gole@ti.com>, <linux-mtd@lists.infradead.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <Takahiro.Kuwano@infineon.com>, Pratyush Yadav <ptyadav@amazon.de>
Subject: [PATCH v2 1/4] spi: cadence-quadspi: Reset CMD_CTRL Reg on cmd r/w completion
Date:   Wed, 25 Jan 2023 13:40:20 +0530
Message-ID: <20230125081023.1573712-2-d-gole@ti.com>
In-Reply-To: <20230125081023.1573712-1-d-gole@ti.com>
References: <20230125081023.1573712-1-d-gole@ti.com>
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If one leaves the CQSPI_REG_CMDCTRL in an unclean state this may cause
issues in future command reads. This issue came to light when some flash
reads in STIG mode were coming back dirty.

Signed-off-by: Dhruva Gole <d-gole@ti.com>
---
 drivers/spi/spi-cadence-quadspi.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 676313e1bdad..6030da942c6e 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -549,6 +549,9 @@ static int cqspi_command_read(struct cqspi_flash_pdata *f_pdata,
 		memcpy(rxbuf, &reg, read_len);
 	}

+	/* Reset CMD_CTRL Reg once command read completes */
+	writel(0, reg_base + CQSPI_REG_CMDCTRL);
+
 	return 0;
 }

@@ -613,7 +616,12 @@ static int cqspi_command_write(struct cqspi_flash_pdata *f_pdata,
 		}
 	}

-	return cqspi_exec_flash_cmd(cqspi, reg);
+	ret = cqspi_exec_flash_cmd(cqspi, reg);
+
+	/* Reset CMD_CTRL Reg once command write completes */
+	writel(0, reg_base + CQSPI_REG_CMDCTRL);
+
+	return ret;
 }

 static int cqspi_read_setup(struct cqspi_flash_pdata *f_pdata,
--
2.25.1