mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-31 03:35:32 -04:00
Code Issues Packages Projects Releases Wiki Activity

spi: dw: update NDF while using enhanced spi mode

Browse Source 
If the transfer of Transmit only mode is using enhanced SPI then
NDF needs to be updated with the number of data frames.
If the Transmit FIFO goes empty in-between, DWC_ssi masks the serial
clock and wait for rest of the data until the programmed amount of
frames are transferred successfully.
In receive mode, the number of data frames received is equal to this
register value plus 1.
In transmit mode, the number of data frames is equal this register
value.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@sifive.com>
Co-developed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Signed-off-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Link: https://patch.msgid.link/20260803124044.156998-6-changhuang.liang@starfivetech.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Sudip Mukherjee
2026-08-03 05:40:38 -07:00
committed by Mark Brown
parent 3d7fd27c97
commit 8678095362
1 changed files with 3 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/spi/spi-dw-core.c
View File

@@ -348,6 +348,9 @@ void dw_spi_update_config(struct dw_spi *dws, struct spi_device *spi,
if (cfg->tmode == DW_SPI_CTRLR0_TMOD_EPROMREAD ||
cfg->tmode == DW_SPI_CTRLR0_TMOD_RO)
dw_writel(dws, DW_SPI_CTRLR1, cfg->ndf ? cfg->ndf - 1 : 0);
else if (cfg->tmode == DW_SPI_CTRLR0_TMOD_TO &&
dws->caps & DW_SPI_CAP_EMODE)
dw_writel(dws, DW_SPI_CTRLR1, cfg->ndf);
/* Note DW APB SSI clock divider doesn't support odd numbers */
clk_div = (DIV_ROUND_UP(dws->max_freq, cfg->freq) + 1) & 0xfffe;