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spi: rockchip: Stop spi slave dma receiver when cs inactive

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The spi which's version is higher than ver 2 will automatically
enable this feature.

If the length of master transmission is uncertain, the RK spi slave
is better to automatically stop after cs inactive instead of waiting
for xfer_completion forever.

Signed-off-by: Jon Lin <jon.lin@rock-chips.com>
Link: https://lore.kernel.org/r/20220216014028.8123-4-jon.lin@rock-chips.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Jon Lin 2022-02-16 09:40:25 +08:00 committed by Mark Brown
parent 80808768e4
commit 869f2c94db
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 73 additions and 8 deletions
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81
drivers/spi/spi-rockchip.c
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@ -133,7 +133,8 @@
#define INT_TF_OVERFLOW (1 << 1)
#define INT_RF_UNDERFLOW (1 << 2)
#define INT_RF_OVERFLOW (1 << 3)
#define INT_RF_FULL (1 << 4)
#define INT_RF_FULL (1 << 4)
#define INT_CS_INACTIVE (1 << 6)
/* Bit fields in ICR, 4bit */
#define ICR_MASK 0x0f
@ -194,6 +195,8 @@ struct rockchip_spi {
bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
bool slave_abort;
bool cs_inactive; /* spi slave tansmition stop when cs inactive */
struct spi_transfer *xfer; /* Store xfer temporarily */
};
static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
@ -343,6 +346,15 @@ static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
struct spi_controller *ctlr = dev_id;
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
/* When int_cs_inactive comes, spi slave abort */
if (rs->cs_inactive && readl_relaxed(rs->regs + ROCKCHIP_SPI_IMR) & INT_CS_INACTIVE) {
ctlr->slave_abort(ctlr);
writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
return IRQ_HANDLED;
}
if (rs->tx_left)
rockchip_spi_pio_writer(rs);
@ -350,6 +362,7 @@ static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
if (!rs->rx_left) {
spi_enable_chip(rs, false);
writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
spi_finalize_current_transfer(ctlr);
}
@ -357,14 +370,18 @@ static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
}
static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
struct spi_transfer *xfer)
struct spi_controller *ctlr,
struct spi_transfer *xfer)
{
rs->tx = xfer->tx_buf;
rs->rx = xfer->rx_buf;
rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
rs->rx_left = xfer->len / rs->n_bytes;
writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
if (rs->cs_inactive)
writel_relaxed(INT_RF_FULL | INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
else
writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
spi_enable_chip(rs, true);
if (rs->tx_left)
@ -383,6 +400,9 @@ static void rockchip_spi_dma_rxcb(void *data)
if (state & TXDMA && !rs->slave_abort)
return;
if (rs->cs_inactive)
writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
spi_enable_chip(rs, false);
spi_finalize_current_transfer(ctlr);
}
@ -423,14 +443,16 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
atomic_set(&rs->state, 0);
rs->tx = xfer->tx_buf;
rs->rx = xfer->rx_buf;
rxdesc = NULL;
if (xfer->rx_buf) {
struct dma_slave_config rxconf = {
.direction = DMA_DEV_TO_MEM,
.src_addr = rs->dma_addr_rx,
.src_addr_width = rs->n_bytes,
.src_maxburst = rockchip_spi_calc_burst_size(xfer->len /
rs->n_bytes),
.src_maxburst = rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes),
};
dmaengine_slave_config(ctlr->dma_rx, &rxconf);
@ -474,10 +496,13 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
/* rx must be started before tx due to spi instinct */
if (rxdesc) {
atomic_or(RXDMA, &rs->state);
dmaengine_submit(rxdesc);
ctlr->dma_rx->cookie = dmaengine_submit(rxdesc);
dma_async_issue_pending(ctlr->dma_rx);
}
if (rs->cs_inactive)
writel_relaxed(INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
spi_enable_chip(rs, true);
if (txdesc) {
@ -584,7 +609,42 @@ static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
{
struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
u32 rx_fifo_left;
struct dma_tx_state state;
enum dma_status status;
/* Get current dma rx point */
if (atomic_read(&rs->state) & RXDMA) {
dmaengine_pause(ctlr->dma_rx);
status = dmaengine_tx_status(ctlr->dma_rx, ctlr->dma_rx->cookie, &state);
if (status == DMA_ERROR) {
rs->rx = rs->xfer->rx_buf;
rs->xfer->len = 0;
rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
for (; rx_fifo_left; rx_fifo_left--)
readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
goto out;
} else {
rs->rx += rs->xfer->len - rs->n_bytes * state.residue;
}
}
/* Get the valid data left in rx fifo and set rs->xfer->len real rx size */
if (rs->rx) {
rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
for (; rx_fifo_left; rx_fifo_left--) {
u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
if (rs->n_bytes == 1)
*(u8 *)rs->rx = (u8)rxw;
else
*(u16 *)rs->rx = (u16)rxw;
rs->rx += rs->n_bytes;
}
rs->xfer->len = (unsigned int)(rs->rx - rs->xfer->rx_buf);
}
out:
if (atomic_read(&rs->state) & RXDMA)
dmaengine_terminate_sync(ctlr->dma_rx);
if (atomic_read(&rs->state) & TXDMA)
@ -626,7 +686,7 @@ static int rockchip_spi_transfer_one(
}
rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
rs->xfer = xfer;
use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
@ -636,7 +696,7 @@ static int rockchip_spi_transfer_one(
if (use_dma)
return rockchip_spi_prepare_dma(rs, ctlr, xfer);
return rockchip_spi_prepare_irq(rs, xfer);
return rockchip_spi_prepare_irq(rs, ctlr, xfer);
}
static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
@ -815,8 +875,13 @@ static int rockchip_spi_probe(struct platform_device *pdev)
switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
case ROCKCHIP_SPI_VER2_TYPE2:
ctlr->mode_bits |= SPI_CS_HIGH;
if (ctlr->can_dma && slave_mode)
rs->cs_inactive = true;
else
rs->cs_inactive = false;
break;
default:
rs->cs_inactive = false;
break;
}