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authorSerge Semin <Sergey.Semin@baikalelectronics.ru>2020-10-08 02:54:51 +0300
committerMark Brown <broonie@kernel.org>2020-10-08 23:00:06 +0100
commitd6bbd1193fe93b7ee037724553b3574dcb48e6da (patch)
tree461e7a0c31caec157ceb264f8d30073a38a21b7b /drivers/spi/spi-dw-core.c
parentf68fe8de360b9c441caf22f35557b4c9fd97dd84 (diff)
downloadlinux-d6bbd1193fe93b7ee037724553b3574dcb48e6da.tar.bz2
spi: dw: Add DWC SSI capability
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>
Diffstat (limited to 'drivers/spi/spi-dw-core.c')
-rw-r--r--drivers/spi/spi-dw-core.c80
1 files changed, 37 insertions, 43 deletions
diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
index 3a7fdca8d335..be16fdaf7ce0 100644
--- a/drivers/spi/spi-dw-core.c
+++ b/drivers/spi/spi-dw-core.c
@@ -228,60 +228,56 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id)
return dws->transfer_handler(dws);
}
-/* Configure CTRLR0 for DW_apb_ssi */
-u32 dw_spi_update_cr0(struct spi_controller *master, struct spi_device *spi,
- struct spi_transfer *transfer)
+static void dw_spi_update_cr0(struct dw_spi *dws, struct spi_device *spi,
+ struct spi_transfer *transfer)
{
struct chip_data *chip = spi_get_ctldata(spi);
u32 cr0;
- /* Default SPI mode is SCPOL = 0, SCPH = 0 */
- cr0 = (transfer->bits_per_word - 1)
- | (SSI_MOTO_SPI << SPI_FRF_OFFSET)
- | ((((spi->mode & SPI_CPOL) ? 1 : 0) << SPI_SCOL_OFFSET) |
- (((spi->mode & SPI_CPHA) ? 1 : 0) << SPI_SCPH_OFFSET) |
- (((spi->mode & SPI_LOOP) ? 1 : 0) << SPI_SRL_OFFSET))
- | (chip->tmode << SPI_TMOD_OFFSET);
+ /* CTRLR0[ 4/3: 0] Data Frame Size */
+ cr0 = (transfer->bits_per_word - 1);
- return cr0;
-}
-EXPORT_SYMBOL_GPL(dw_spi_update_cr0);
+ if (!(dws->caps & DW_SPI_CAP_DWC_SSI)) {
+ /* CTRLR0[ 5: 4] Frame Format */
+ cr0 |= SSI_MOTO_SPI << SPI_FRF_OFFSET;
-/* Configure CTRLR0 for DWC_ssi */
-u32 dw_spi_update_cr0_v1_01a(struct spi_controller *master,
- struct spi_device *spi,
- struct spi_transfer *transfer)
-{
- struct dw_spi *dws = spi_controller_get_devdata(master);
- struct chip_data *chip = spi_get_ctldata(spi);
- u32 cr0;
+ /*
+ * SPI mode (SCPOL|SCPH)
+ * CTRLR0[ 6] Serial Clock Phase
+ * CTRLR0[ 7] Serial Clock Polarity
+ */
+ cr0 |= ((spi->mode & SPI_CPOL) ? 1 : 0) << SPI_SCOL_OFFSET;
+ cr0 |= ((spi->mode & SPI_CPHA) ? 1 : 0) << SPI_SCPH_OFFSET;
- /* CTRLR0[ 4: 0] Data Frame Size */
- cr0 = (transfer->bits_per_word - 1);
+ /* CTRLR0[11] Shift Register Loop */
+ cr0 |= ((spi->mode & SPI_LOOP) ? 1 : 0) << SPI_SRL_OFFSET;
- /* CTRLR0[ 7: 6] Frame Format */
- cr0 |= SSI_MOTO_SPI << DWC_SSI_CTRLR0_FRF_OFFSET;
+ /* CTRLR0[ 9:8] Transfer Mode */
+ cr0 |= chip->tmode << SPI_TMOD_OFFSET;
+ } else {
+ /* CTRLR0[ 7: 6] Frame Format */
+ cr0 |= SSI_MOTO_SPI << DWC_SSI_CTRLR0_FRF_OFFSET;
- /*
- * SPI mode (SCPOL|SCPH)
- * CTRLR0[ 8] Serial Clock Phase
- * CTRLR0[ 9] Serial Clock Polarity
- */
- cr0 |= ((spi->mode & SPI_CPOL) ? 1 : 0) << DWC_SSI_CTRLR0_SCPOL_OFFSET;
- cr0 |= ((spi->mode & SPI_CPHA) ? 1 : 0) << DWC_SSI_CTRLR0_SCPH_OFFSET;
+ /*
+ * SPI mode (SCPOL|SCPH)
+ * CTRLR0[ 8] Serial Clock Phase
+ * CTRLR0[ 9] Serial Clock Polarity
+ */
+ cr0 |= ((spi->mode & SPI_CPOL) ? 1 : 0) << DWC_SSI_CTRLR0_SCPOL_OFFSET;
+ cr0 |= ((spi->mode & SPI_CPHA) ? 1 : 0) << DWC_SSI_CTRLR0_SCPH_OFFSET;
- /* CTRLR0[11:10] Transfer Mode */
- cr0 |= chip->tmode << DWC_SSI_CTRLR0_TMOD_OFFSET;
+ /* CTRLR0[13] Shift Register Loop */
+ cr0 |= ((spi->mode & SPI_LOOP) ? 1 : 0) << DWC_SSI_CTRLR0_SRL_OFFSET;
- /* CTRLR0[13] Shift Register Loop */
- cr0 |= ((spi->mode & SPI_LOOP) ? 1 : 0) << DWC_SSI_CTRLR0_SRL_OFFSET;
+ /* CTRLR0[11:10] Transfer Mode */
+ cr0 |= chip->tmode << DWC_SSI_CTRLR0_TMOD_OFFSET;
- if (dws->caps & DW_SPI_CAP_KEEMBAY_MST)
- cr0 |= DWC_SSI_CTRLR0_KEEMBAY_MST;
+ if (dws->caps & DW_SPI_CAP_KEEMBAY_MST)
+ cr0 |= DWC_SSI_CTRLR0_KEEMBAY_MST;
+ }
- return cr0;
+ dw_writel(dws, DW_SPI_CTRLR0, cr0);
}
-EXPORT_SYMBOL_GPL(dw_spi_update_cr0_v1_01a);
static int dw_spi_transfer_one(struct spi_controller *master,
struct spi_device *spi, struct spi_transfer *transfer)
@@ -290,7 +286,6 @@ static int dw_spi_transfer_one(struct spi_controller *master,
struct chip_data *chip = spi_get_ctldata(spi);
u8 imask = 0;
u16 txlevel = 0;
- u32 cr0;
int ret;
dws->dma_mapped = 0;
@@ -319,8 +314,7 @@ static int dw_spi_transfer_one(struct spi_controller *master,
transfer->effective_speed_hz = dws->max_freq / chip->clk_div;
- cr0 = dws->update_cr0(master, spi, transfer);
- dw_writel(dws, DW_SPI_CTRLR0, cr0);
+ dw_spi_update_cr0(dws, spi, transfer);
/* Check if current transfer is a DMA transaction */
if (master->can_dma && master->can_dma(master, spi, transfer))