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From: Marco Felsch <m.felsch@pengutronix.de>
To: tudor.ambarus@microchip.com, miquel.raynal@bootlin.com,
	richard@nod.at, vigneshr@ti.com,
	sergei.shtylyov@cogentembedded.com,
	boris.brezillon@collabora.com, michael@walle.cc,
	j.neuschaefer@gmx.net
Cc: linux-mtd@lists.infradead.org, kernel@pengutronix.de,
	linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] mtd: spi-nor: sst: add missing write_enable
Date: Fri, 11 Sep 2020 16:47:02 +0200	[thread overview]
Message-ID: <20200911144703.25409-3-m.felsch@pengutronix.de> (raw)
In-Reply-To: <20200911144703.25409-1-m.felsch@pengutronix.de>

According the datasheet [1] the WEL is automatically reset after the
Byte-Program instruction completion. So if we program the device with
byte-size set to 32 and starting from an odd address only the first and
the last byte is written. Fix this by (re-)anble the write support for
the first SPINOR_OP_AAI_WP sequence.

[1] http://ww1.microchip.com/downloads/en/DeviceDoc/20005044C.pdf;
    "4.3.2 WRITE ENABLE LATCH (WEL)"

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/mtd/spi-nor/sst.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
index e0af6d25d573..644252e27a2a 100644
--- a/drivers/mtd/spi-nor/sst.c
+++ b/drivers/mtd/spi-nor/sst.c
@@ -79,6 +79,13 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	/* Write out most of the data here. */
 	for (; actual < len - 1; actual += 2) {
+		/* Enable write support if odd address was written before */
+		if (actual == 1) {
+			ret = spi_nor_write_enable(nor);
+			if (ret)
+				goto out;
+		}
+
 		nor->program_opcode = SPINOR_OP_AAI_WP;
 
 		/* write two bytes. */
-- 
2.20.1


WARNING: multiple messages have this Message-ID (diff)
From: Marco Felsch <m.felsch@pengutronix.de>
To: tudor.ambarus@microchip.com, miquel.raynal@bootlin.com,
	richard@nod.at, vigneshr@ti.com,
	sergei.shtylyov@cogentembedded.com,
	boris.brezillon@collabora.com, michael@walle.cc,
	j.neuschaefer@gmx.net
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	kernel@pengutronix.de
Subject: [PATCH 2/3] mtd: spi-nor: sst: add missing write_enable
Date: Fri, 11 Sep 2020 16:47:02 +0200	[thread overview]
Message-ID: <20200911144703.25409-3-m.felsch@pengutronix.de> (raw)
In-Reply-To: <20200911144703.25409-1-m.felsch@pengutronix.de>

According the datasheet [1] the WEL is automatically reset after the
Byte-Program instruction completion. So if we program the device with
byte-size set to 32 and starting from an odd address only the first and
the last byte is written. Fix this by (re-)anble the write support for
the first SPINOR_OP_AAI_WP sequence.

[1] http://ww1.microchip.com/downloads/en/DeviceDoc/20005044C.pdf;
    "4.3.2 WRITE ENABLE LATCH (WEL)"

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/mtd/spi-nor/sst.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
index e0af6d25d573..644252e27a2a 100644
--- a/drivers/mtd/spi-nor/sst.c
+++ b/drivers/mtd/spi-nor/sst.c
@@ -79,6 +79,13 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	/* Write out most of the data here. */
 	for (; actual < len - 1; actual += 2) {
+		/* Enable write support if odd address was written before */
+		if (actual == 1) {
+			ret = spi_nor_write_enable(nor);
+			if (ret)
+				goto out;
+		}
+
 		nor->program_opcode = SPINOR_OP_AAI_WP;
 
 		/* write two bytes. */
-- 
2.20.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  parent reply	other threads:[~2020-09-11 16:55 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-11 14:47 [PATCH 0/3] MTD: SST SPI-NOR fixes Marco Felsch
2020-09-11 14:47 ` Marco Felsch
2020-09-11 14:47 ` [PATCH 1/3] mtd: spi-nor: sst: fix write support for SST_WRITE marked devices Marco Felsch
2020-09-11 14:47   ` Marco Felsch
2020-09-14 12:00   ` Vignesh Raghavendra
2020-09-14 12:00     ` Vignesh Raghavendra
2020-09-16  9:36     ` Tudor.Ambarus
2020-09-16  9:36       ` Tudor.Ambarus
2020-09-11 14:47 ` Marco Felsch [this message]
2020-09-11 14:47   ` [PATCH 2/3] mtd: spi-nor: sst: add missing write_enable Marco Felsch
2020-09-11 14:47 ` [PATCH 3/3] mtd: spi-nor: sst: move sst_write_second to local driver Marco Felsch
2020-09-11 14:47   ` Marco Felsch
2020-11-24 20:35 ` [PATCH 0/3] MTD: SST SPI-NOR fixes Michael Auchter
2020-11-24 20:35   ` Michael Auchter

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