[PATCH v10 4/9] spi: cadence: Add Marvell SDMA operations

From: Witold Sadowski
Date: Tue Jul 09 2024 - 18:12:42 EST


In Marvell xSPI implementation any access to SDMA register will result
in 8 byte SPI data transfer. Reading less data(eg. 1B) will result in
losing remaining bytes. To avoid that read/write 8 bytes into temporary
buffer, and read/write whole temporary buffer into SDMA.

Signed-off-by: Witold Sadowski <wsadowski@xxxxxxxxxxx>
---
drivers/spi/spi-cadence-xspi.c | 72 ++++++++++++++++++++++++++++++++--
1 file changed, 69 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index d0222284c507..5952ca4593bb 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -310,6 +310,7 @@ struct cdns_xspi_dev {
u8 hw_num_banks;

const struct cdns_xspi_driver_data *driver_data;
+ void (*sdma_handler)(struct cdns_xspi_dev *cdns_xspi);
};

static void cdns_xspi_reset_dll(struct cdns_xspi_dev *cdns_xspi)
@@ -515,6 +516,68 @@ static void cdns_xspi_sdma_handle(struct cdns_xspi_dev *cdns_xspi)
}
}

+static void m_ioreadq(void __iomem *addr, void *buf, int len)
+{
+ if (IS_ALIGNED((long)buf, 8) && len >= 8) {
+ u64 full_ops = len / 8;
+
+ ioread64_rep(addr, buf, full_ops);
+ len -= full_ops * 8;
+ buf += full_ops * 8;
+ }
+
+ while (len) {
+ u64 tmp_buf;
+
+ tmp_buf = readq(addr);
+ memcpy(buf, &tmp_buf, min(len, 8));
+ len = len > 8 ? len - 8 : 0;
+ buf += 8;
+ }
+}
+
+static void m_iowriteq(void __iomem *addr, const void *buf, int len)
+{
+ if (IS_ALIGNED((long)buf, 8) && len >= 8) {
+ u64 full_ops = len / 8;
+
+ iowrite64_rep(addr, buf, full_ops);
+ len -= full_ops * 8;
+ buf += full_ops * 8;
+ }
+
+ while (len) {
+ u64 tmp_buf;
+
+ memcpy(&tmp_buf, buf, min(len, 8));
+ writeq(tmp_buf, addr);
+ len = len > 8 ? len - 8 : 0;
+ buf += 8;
+ }
+}
+
+static void marvell_xspi_sdma_handle(struct cdns_xspi_dev *cdns_xspi)
+{
+ u32 sdma_size, sdma_trd_info;
+ u8 sdma_dir;
+
+ sdma_size = readl(cdns_xspi->iobase + CDNS_XSPI_SDMA_SIZE_REG);
+ sdma_trd_info = readl(cdns_xspi->iobase + CDNS_XSPI_SDMA_TRD_INFO_REG);
+ sdma_dir = FIELD_GET(CDNS_XSPI_SDMA_DIR, sdma_trd_info);
+
+ switch (sdma_dir) {
+ case CDNS_XSPI_SDMA_DIR_READ:
+ m_ioreadq(cdns_xspi->sdmabase,
+ cdns_xspi->in_buffer, sdma_size);
+ break;
+
+ case CDNS_XSPI_SDMA_DIR_WRITE:
+ m_iowriteq(cdns_xspi->sdmabase,
+ cdns_xspi->out_buffer, sdma_size);
+ break;
+ }
+}
+
static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi,
const struct spi_mem_op *op,
bool data_phase)
@@ -566,7 +629,7 @@ static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi,
cdns_xspi_set_interrupts(cdns_xspi, false);
return -EIO;
}
- cdns_xspi_sdma_handle(cdns_xspi);
+ cdns_xspi->sdma_handler(cdns_xspi);
}

wait_for_completion(&cdns_xspi->cmd_complete);
@@ -736,10 +799,13 @@ static int cdns_xspi_probe(struct platform_device *pdev)
if (!cdns_xspi->driver_data)
return -ENODEV;

- if (cdns_xspi->driver_data->mrvl_hw_overlay)
+ if (cdns_xspi->driver_data->mrvl_hw_overlay) {
host->mem_ops = &marvell_xspi_mem_ops;
- else
+ cdns_xspi->sdma_handler = &marvell_xspi_sdma_handle;
+ } else {
host->mem_ops = &cadence_xspi_mem_ops;
+ cdns_xspi->sdma_handler = &cdns_xspi_sdma_handle;
+ }
host->dev.of_node = pdev->dev.of_node;
host->bus_num = -1;

--
2.43.0