[PATCH 1/7] spi: add slave device size in spi_device struct

Yogesh Gaur
2018-08-31T10:32:06Z

Add 'size' data variable in spi_device struct.
This is to save the size of the connected slave device.

After slave device scan, spi_nor_scan, size being assigned to this
from MTD layer.

SFDP read is being requested before completion of spi_nor_scan()
routine, thus populate device size before making read request
to the SPI controller.

Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@nxp.com>
---
drivers/mtd/devices/m25p80.c | 6 ++++++
drivers/mtd/spi-nor/spi-nor.c | 2 ++
include/linux/spi/spi.h | 2 ++
3 files changed, 10 insertions(+)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index fe260cc..6c7ad86 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -124,6 +124,10 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
/* convert the dummy cycles to the number of bytes */
op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;

+ /* for case of SFDP header read commands, populate spi device size */
+ if (flash->spimem->spi->size == 0)
+ flash->spimem->spi->size = nor->mtd.size;
+
while (remaining) {
op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
ret = spi_mem_adjust_op_size(flash->spimem, &op);
@@ -215,6 +219,8 @@ static int m25p_probe(struct spi_mem *spimem)
if (ret)
return ret;

+ spi->size = nor->mtd.size;
+
return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
data ? data->nr_parts : 0);
}
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 6042df8..b066bed 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2864,6 +2864,8 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
if (info->flags & SPI_S3AN)
nor->flags |= SNOR_F_READY_XSR_RDY;

+ mtd->size = info->sector_size * info->n_sectors;
+
/* Parse the Serial Flash Discoverable Parameters table. */
ret = spi_nor_init_params(nor, info, &params);
if (ret)
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index a64235e..558aeed 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -127,6 +127,7 @@ void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
* for driver coldplugging, and in uevents used for hotplugging
* @cs_gpio: gpio number of the chipselect line (optional, -ENOENT when
* not using a GPIO line)
+ * @size: size of the connected slave device
*
* @statistics: statistics for the spi_device
*
@@ -168,6 +169,7 @@ struct spi_device {
void *controller_data;
char modalias[SPI_NAME_SIZE];
int cs_gpio; /* chip select gpio */
+ u32 size; /* size of slave device */

/* the statistics */
struct spi_statistics statistics;
--
2.7.4