xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

spi: dw: Add DWC SSI capability

Browse Source 
Currently DWC SSI core is supported by means of setting up the
core-specific update_cr0() callback. It isn't suitable for multiple
reasons. First of all having exported several methods doing the same thing
but for different chips makes the code harder to maintain. Secondly the
spi-dw-core driver exports the methods, then the spi-dw-mmio driver sets
the private data callback with one of them so to be called by the core
driver again. That makes the code logic too complicated. Thirdly using
callbacks for just updating the CR0 register is problematic, since in case
if the register needed to be updated from different parts of the code,
we'd have to create another callback (for instance the SPI device-specific
parameters don't need to be calculated each time the SPI transfer is
submitted, so it's better to pre-calculate the CR0 data at the SPI-device
setup stage).

So keeping all the above in mind let's discard the update_cr0() callbacks,
define a generic and static dw_spi_update_cr0() method and create the
DW_SPI_CAP_DWC_SSI capability, which when enabled would activate the
alternative CR0 register layout.

While at it add the comments to the code path of the normal DW APB SSI
controller setup to make the dw_spi_update_cr0() method looking coherent.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201007235511.4935-3-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Serge Semin
2020-10-08 02:54:51 +03:00
committed by Mark Brown
parent f68fe8de36
commit d6bbd1193f
4 changed files with 42 additions and 77 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/spi/spi-dw-pci.c
View File

@@ -48,9 +48,6 @@ static int spi_mid_init(struct dw_spi *dws)
iounmap(clk_reg);
/* Register hook to configure CTRLR0 */
dws->update_cr0 = dw_spi_update_cr0;
dw_spi_dma_setup_mfld(dws);
return 0;
@@ -58,9 +55,6 @@ static int spi_mid_init(struct dw_spi *dws)
static int spi_generic_init(struct dw_spi *dws)
{
/* Register hook to configure CTRLR0 */
dws->update_cr0 = dw_spi_update_cr0;
dw_spi_dma_setup_generic(dws);
return 0;