From: Tudor Ambarus <tudor.ambarus@microchip.com>
To: <p.yadav@ti.com>, <michael@walle.cc>, <broonie@kernel.org>
Cc: <miquel.raynal@bootlin.com>, <richard@nod.at>, <vigneshr@ti.com>,
<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
<linux-spi@vger.kernel.org>, <nicolas.ferre@microchip.com>,
Tudor Ambarus <tudor.ambarus@microchip.com>
Subject: [PATCH v2 2/6] mtd: spi-nor: core: Allow specifying the byte order in DTR mode
Date: Fri, 11 Mar 2022 10:01:43 +0200 [thread overview]
Message-ID: <20220311080147.453483-3-tudor.ambarus@microchip.com> (raw)
In-Reply-To: <20220311080147.453483-1-tudor.ambarus@microchip.com>
Macronix swaps bytes on a 16-bit boundary when configured in Octal DTR.
The byte order of 16-bit words is swapped when read or written in 8D-8D-8D
mode compared to STR modes. Allow operations to specify the byte order in
DTR mode, so that controllers can swap the bytes back at run-time to
address the flash's endianness requirements, if they are capable. If the
controllers are not capable of swapping the bytes, the protocol is
downgraded via spi_nor_spimem_adjust_hwcaps(). When available, the swapping
of the bytes is always done regardless if it's a data or register access,
so that we comply with the JESD216 requirements: "Byte order of 16-bit
words is swapped when read in 8D-8D-8D mode compared to 1-1-1".
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
drivers/mtd/spi-nor/core.c | 8 ++++++++
drivers/mtd/spi-nor/core.h | 1 +
2 files changed, 9 insertions(+)
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 5de46a786cc5..a69c2813f6fc 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -70,6 +70,13 @@ static u8 spi_nor_get_cmd_ext(const struct spi_nor *nor,
}
}
+static inline bool spi_nor_is_octal_dtr_swab16(const struct spi_nor *nor,
+ enum spi_nor_protocol proto)
+{
+ return (proto == SNOR_PROTO_8_8_8_DTR) &&
+ (nor->flags & SNOR_F_DTR_SWAB16);
+}
+
/**
* spi_nor_spimem_setup_op() - Set up common properties of a spi-mem op.
* @nor: pointer to a 'struct spi_nor'
@@ -105,6 +112,7 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor,
op->addr.dtr = true;
op->dummy.dtr = true;
op->data.dtr = true;
+ op->data.dtr_swab16 = spi_nor_is_octal_dtr_swab16(nor, proto);
/* 2 bytes per clock cycle in DTR mode. */
op->dummy.nbytes *= 2;
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index c83d5e75c563..0dcbc7a81e64 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -135,6 +135,7 @@ enum spi_nor_option_flags {
SNOR_F_IO_MODE_EN_VOLATILE = BIT(11),
SNOR_F_SOFT_RESET = BIT(12),
SNOR_F_SWP_IS_VOLATILE = BIT(13),
+ SNOR_F_DTR_SWAB16 = BIT(14),
};
struct spi_nor_read_command {
--
2.25.1
next prev parent reply other threads:[~2022-03-11 8:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-11 8:01 [PATCH v2 0/6] spi-mem: Allow specifying the byte order in DTR mode Tudor Ambarus
2022-03-11 8:01 ` [PATCH v2 1/6] spi: " Tudor Ambarus
2022-03-11 8:01 ` Tudor Ambarus [this message]
2022-03-11 8:01 ` [PATCH v2 3/6] mtd: spi-nor: sfdp: Get the 8D-8D-8D byte order from BFPT Tudor Ambarus
2022-03-11 8:01 ` [PATCH v2 4/6] mtd: spi-nor: core: Introduce SPI_NOR_DTR_BSWAP16 no_sfdp_flag Tudor Ambarus
2022-03-11 8:01 ` [PATCH v2 5/6] mtd: spi-nor: core: Introduce SPI_NOR_SOFT_RESET flash_info fixup_flag Tudor Ambarus
2022-03-11 8:01 ` [PATCH v2 6/6] mtd: spi-nor: macronix: Add support for mx66lm1g45g Tudor Ambarus
2022-03-15 6:08 ` [PATCH v2 0/6] spi-mem: Allow specifying the byte order in DTR mode Vignesh Raghavendra
2022-03-15 6:58 ` Tudor.Ambarus
2022-03-16 7:08 ` Vignesh Raghavendra
2022-03-16 8:39 ` Michael Walle
2022-03-15 7:19 ` Michael Walle
2022-03-16 7:05 ` Vignesh Raghavendra
2022-03-16 7:57 ` Tudor.Ambarus
2022-03-16 13:55 ` David Laight
2022-03-17 9:40 ` Michael Walle
2022-03-17 10:14 ` David Laight
2022-03-17 10:23 ` Vignesh Raghavendra
2022-03-17 11:10 ` David Laight
2022-03-17 16:49 ` Vignesh Raghavendra
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