From: Pratyush Yadav <p.yadav@ti.com>
To: Tudor Ambarus <tudor.ambarus@microchip.com>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Mark Brown <broonie@kernel.org>,
Nicolas Ferre <nicolas.ferre@microchip.com>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Ludovic Desroches <ludovic.desroches@microchip.com>,
<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
<linux-spi@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>
Cc: Sekhar Nori <nsekhar@ti.com>, Pratyush Yadav <p.yadav@ti.com>
Subject: [PATCH v4 10/16] mtd: spi-nor: do 2 byte reads for SR and FSR in DTR mode
Date: Sat, 25 Apr 2020 00:14:04 +0530 [thread overview]
Message-ID: <20200424184410.8578-11-p.yadav@ti.com> (raw)
In-Reply-To: <20200424184410.8578-1-p.yadav@ti.com>
Some controllers, like the cadence qspi controller, have trouble reading
only 1 byte in DTR mode. So, do 2 byte reads for SR and FSR commands in
DTR mode, and then discard the second byte.
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
---
drivers/mtd/spi-nor/core.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 3d181c7deda7..6eb2b1781972 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -350,7 +350,7 @@ int spi_nor_write_disable(struct spi_nor *nor)
* spi_nor_read_sr() - Read the Status Register.
* @nor: pointer to 'struct spi_nor'.
* @sr: pointer to a DMA-able buffer where the value of the
- * Status Register will be written.
+ * Status Register will be written. Should be at least 2 bytes.
*
* Return: 0 on success, -errno otherwise.
*/
@@ -371,6 +371,11 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
op.addr.nbytes = addr_bytes;
op.addr.val = 0;
op.dummy.nbytes = dummy;
+ /*
+ * We don't want to read only one byte in DTR mode. So,
+ * read 2 and then discard the second byte.
+ */
+ op.data.nbytes = 2;
}
spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
@@ -394,7 +399,8 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
* spi_nor_read_fsr() - Read the Flag Status Register.
* @nor: pointer to 'struct spi_nor'
* @fsr: pointer to a DMA-able buffer where the value of the
- * Flag Status Register will be written.
+ * Flag Status Register will be written. Should be at least 2
+ * bytes.
*
* Return: 0 on success, -errno otherwise.
*/
@@ -415,6 +421,11 @@ static int spi_nor_read_fsr(struct spi_nor *nor, u8 *fsr)
op.addr.nbytes = addr_bytes;
op.addr.val = 0;
op.dummy.nbytes = dummy;
+ /*
+ * We don't want to read only one byte in DTR mode. So,
+ * read 2 and then discard the second byte.
+ */
+ op.data.nbytes = 2;
}
spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
--
2.25.0
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next prev parent reply other threads:[~2020-04-24 18:51 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-24 18:43 [PATCH v4 00/16] mtd: spi-nor: add xSPI Octal DTR support Pratyush Yadav
2020-04-24 18:43 ` [PATCH v4 01/16] spi: spi-mem: allow specifying whether an op is DTR or not Pratyush Yadav
2020-04-24 18:43 ` [PATCH v4 02/16] spi: atmel-quadspi: reject DTR ops Pratyush Yadav
2020-04-30 11:32 ` Mark Brown
2020-04-30 12:17 ` Pratyush Yadav
2020-04-30 12:19 ` Mark Brown
2020-04-24 18:43 ` [PATCH v4 03/16] spi: spi-mem: allow specifying a command's extension Pratyush Yadav
2020-04-24 18:43 ` [PATCH v4 04/16] mtd: spi-nor: add support for DTR protocol Pratyush Yadav
2020-04-24 18:43 ` [PATCH v4 05/16] mtd: spi-nor: default to address width of 3 for configurable widths Pratyush Yadav
2020-04-26 3:53 ` Yicong Yang
2020-04-27 17:23 ` Pratyush Yadav
2020-04-28 1:34 ` Yicong Yang
2020-04-28 5:25 ` Tudor.Ambarus
2020-04-24 18:44 ` [PATCH v4 06/16] mtd: spi-nor: prepare BFPT parsing for JESD216 rev D Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 07/16] mtd: spi-nor: get command opcode extension type from BFPT Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 08/16] mtd: spi-nor: parse xSPI Profile 1.0 table Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 09/16] mtd: spi-nor: use dummy cycle and address width info from SFDP Pratyush Yadav
2020-04-24 18:44 ` Pratyush Yadav [this message]
2020-04-24 18:44 ` [PATCH v4 11/16] mtd: spi-nor: enable octal DTR mode when possible Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 12/16] mtd: spi-nor: perform a Soft Reset on shutdown Pratyush Yadav
2020-05-10 11:22 ` Tudor.Ambarus
2020-05-11 18:01 ` Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 13/16] mtd: spi-nor: Disable Octal DTR mode on suspend Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 14/16] mtd: spi-nor: expose spi_nor_default_setup() in core.h Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 15/16] mtd: spi-nor: add support for Cypress Semper flash Pratyush Yadav
2020-04-24 18:44 ` [PATCH v4 16/16] mtd: spi-nor: allow using MT35XU512ABA in Octal DTR mode Pratyush Yadav
2020-05-11 9:00 ` [PATCH v4 00/16] mtd: spi-nor: add xSPI Octal DTR support Tudor.Ambarus
2020-05-11 9:27 ` Boris Brezillon
2020-05-11 18:24 ` Pratyush Yadav
2020-05-12 6:16 ` Tudor.Ambarus
2020-05-12 9:49 ` Vignesh Raghavendra
2020-05-12 11:29 ` Tudor.Ambarus
2020-05-12 18:46 ` Pratyush Yadav
2020-05-11 9:43 ` Vignesh Raghavendra
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