The TI QSPI IP has limitations:
- the MMIO region is 64MB in size
- in non-MMIO mode, the transfer can handle 4096 words max.
Add support for bigger devices.
Use MMIO and DMA transfers below the 64MB boundary, use
software generated transfers above.
Signed-off-by: Jean Pihet <jean.pihet@xxxxxxxxxxxxxx>
Cc: Ryan Barnett <ryan.barnett@xxxxxxxxxxxxxxxxxxx>
Cc: Conrad Ratschan <conrad.ratschan@xxxxxxxxxxxxxxxxxxx>
Cc: Arnout Vandecappelle <arnout.vandecappelle@xxxxxxxxxxxxx>
---
drivers/spi/spi-ti-qspi.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index ad2942b3d0a9..0334e2926998 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -525,6 +525,35 @@ static void ti_qspi_setup_mmap_read(struct spi_device *spi, u8 opcode,
QSPI_SPI_SETUP_REG(spi->chip_select));
}
+static int ti_qspi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+{
+ struct ti_qspi *qspi = spi_controller_get_devdata(mem->spi->master);
+ size_t max_len;
+
+ if (op->data.dir == SPI_MEM_DATA_IN) {
+ if (op->addr.val < qspi->mmap_size) {
+ /* Limit MMIO to the mmaped region */
+ if (op->addr.val + op->data.nbytes > qspi->mmap_size) {
+ max_len = qspi->mmap_size - op->addr.val;
+ op->data.nbytes = min((size_t) op->data.nbytes,
+ max_len);
+ }
+ } else {
+ /*
+ * Use fallback mode (SW generated transfers) above the
+ * mmaped region.
+ * Adjust size to comply with the QSPI max frame length.
+ */
+ max_len = QSPI_FRAME;
+ max_len -= 1 + op->addr.nbytes + op->dummy.nbytes;
+ op->data.nbytes = min((size_t) op->data.nbytes,
+ max_len);
+ }
+ }
+
+ return 0;
+}
+
static int ti_qspi_exec_mem_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
@@ -575,6 +604,7 @@ static int ti_qspi_exec_mem_op(struct spi_mem *mem,
static const struct spi_controller_mem_ops ti_qspi_mem_ops = {
.exec_op = ti_qspi_exec_mem_op,
+ .adjust_op_size = ti_qspi_adjust_op_size,
};
static int ti_qspi_start_transfer_one(struct spi_master *master,
--
2.24.1
