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spi: spi-rockchip: add support for spi slave mode 

Add support for spi slave mode in spi-rockchip. The register map has an entry
for it. If spi-slave is set in dts, set this corresponding bit and add to
mode_bits the SPI_NO_CS, allow slave mode without explicit CS use.
Slave abort function had been added.

Signed-off-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Link: https://lore.kernel.org/r/20200511083022.23678-3-chris.ruehl@gtsys.com.hk
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Chris Ruehl 2020-05-11 16:30:21 +08:00 committed by Mark Brown
parent d66571a20f
commit d065f41a3f
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 38 additions and 6 deletions
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44
drivers/spi/spi-rockchip.c
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@ -183,6 +183,8 @@ struct rockchip_spi {
u8 rsd;
bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
bool slave_abort;
};
static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
@ -359,7 +361,7 @@ static void rockchip_spi_dma_rxcb(void *data)
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
int state = atomic_fetch_andnot(RXDMA, &rs->state);
if (state & TXDMA)
if (state & TXDMA && !rs->slave_abort)
return;
spi_enable_chip(rs, false);
@ -372,7 +374,7 @@ static void rockchip_spi_dma_txcb(void *data)
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
int state = atomic_fetch_andnot(TXDMA, &rs->state);
if (state & RXDMA)
if (state & RXDMA && !rs->slave_abort)
return;
/* Wait until the FIFO data completely. */
@ -457,7 +459,7 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
static void rockchip_spi_config(struct rockchip_spi *rs,
struct spi_device *spi, struct spi_transfer *xfer,
bool use_dma)
bool use_dma, bool slave_mode)
{
u32 cr0 = CR0_FRF_SPI << CR0_FRF_OFFSET
| CR0_BHT_8BIT << CR0_BHT_OFFSET
@ -466,6 +468,10 @@ static void rockchip_spi_config(struct rockchip_spi *rs,
u32 cr1;
u32 dmacr = 0;
if (slave_mode)
cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
rs->slave_abort = false;
cr0 |= rs->rsd << CR0_RSD_OFFSET;
cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
if (spi->mode & SPI_LSB_FIRST)
@ -535,6 +541,16 @@ static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
return ROCKCHIP_SPI_MAX_TRANLEN;
}
static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
{
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
rs->slave_abort = true;
complete(&ctlr->xfer_completion);
return 0;
}
static int rockchip_spi_transfer_one(
struct spi_controller *ctlr,
struct spi_device *spi,
@ -560,7 +576,7 @@ static int rockchip_spi_transfer_one(
use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
rockchip_spi_config(rs, spi, xfer, use_dma);
rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
if (use_dma)
return rockchip_spi_prepare_dma(rs, ctlr, xfer);
@ -588,15 +604,26 @@ static int rockchip_spi_probe(struct platform_device *pdev)
struct rockchip_spi *rs;
struct spi_controller *ctlr;
struct resource *mem;
struct device_node *np = pdev->dev.of_node;
u32 rsd_nsecs;
bool slave_mode;
slave_mode = of_property_read_bool(np, "spi-slave");
if (slave_mode)
ctlr = spi_alloc_slave(&pdev->dev,
sizeof(struct rockchip_spi));
else
ctlr = spi_alloc_master(&pdev->dev,
sizeof(struct rockchip_spi));
ctlr = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
if (!ctlr)
return -ENOMEM;
platform_set_drvdata(pdev, ctlr);
rs = spi_controller_get_devdata(ctlr);
ctlr->slave = slave_mode;
/* Get basic io resource and map it */
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@ -676,6 +703,12 @@ static int rockchip_spi_probe(struct platform_device *pdev)
ctlr->auto_runtime_pm = true;
ctlr->bus_num = pdev->id;
ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
if (slave_mode) {
ctlr->mode_bits |= SPI_NO_CS;
ctlr->slave_abort = rockchip_spi_slave_abort;
} else {
ctlr->flags = SPI_MASTER_GPIO_SS;
}
ctlr->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
ctlr->dev.of_node = pdev->dev.of_node;
ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
@ -686,7 +719,6 @@ static int rockchip_spi_probe(struct platform_device *pdev)
ctlr->transfer_one = rockchip_spi_transfer_one;
ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
ctlr->handle_err = rockchip_spi_handle_err;
ctlr->flags = SPI_MASTER_GPIO_SS;
ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
if (IS_ERR(ctlr->dma_tx)) {