spi: spi-mem: Adjust op len based on message/transfer size limitations

We need that to adjust the len of the 2nd transfer (called data in
spi-mem) if it's too long to fit in a SPI message or SPI transfer.

Fixes: c36ff266dc ("spi: Extend the core to ease integration of SPI memory controllers")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Chuanhua Han 2018-08-30 16:43:24 +08:00 committed by Mark Brown
parent abf5feef3f
commit e757996caf
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0

View file

@ -346,10 +346,25 @@ EXPORT_SYMBOL_GPL(spi_mem_get_name);
int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
{
struct spi_controller *ctlr = mem->spi->controller;
size_t len;
len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
return ctlr->mem_ops->adjust_op_size(mem, op);
if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
if (len > spi_max_transfer_size(mem->spi))
return -EINVAL;
op->data.nbytes = min3((size_t)op->data.nbytes,
spi_max_transfer_size(mem->spi),
spi_max_message_size(mem->spi) -
len);
if (!op->data.nbytes)
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);