mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

spi: rockchip: use atomic_t state 

The state field is currently only used to make sure
only the last of the tx and rx dma callbacks issue
an spi_finalize_current_transfer.
Rather than using a spinlock we can get away
with just turning the state field into an atomic_t.

Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Emil Renner Berthing 2018-10-31 11:57:01 +01:00 committed by Mark Brown
parent 2410d6a3c3
commit fab3e4871f
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 25 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
drivers/spi/spi-rockchip.c
View File

@ -142,8 +142,9 @@
#define RF_DMA_EN (1 << 0)
#define TF_DMA_EN (1 << 1)
#define RXBUSY (1 << 0)
#define TXBUSY (1 << 1)
/* Driver state flags */
#define RXDMA (1 << 0)
#define TXDMA (1 << 1)
/* sclk_out: spi master internal logic in rk3x can support 50Mhz */
#define MAX_SCLK_OUT 50000000
@ -169,6 +170,9 @@ struct rockchip_spi {
struct clk *apb_pclk;
void __iomem *regs;
atomic_t state;
/*depth of the FIFO buffer */
u32 fifo_len;
/* max bus freq supported */
@ -187,10 +191,6 @@ struct rockchip_spi {
void *rx;
void *rx_end;
u32 state;
/* protect state */
spinlock_t lock;
bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
bool use_dma;
@ -302,28 +302,21 @@ static int rockchip_spi_prepare_message(struct spi_master *master,
static void rockchip_spi_handle_err(struct spi_master *master,
struct spi_message *msg)
{
unsigned long flags;
struct rockchip_spi *rs = spi_master_get_devdata(master);
spin_lock_irqsave(&rs->lock, flags);
/*
* For DMA mode, we need terminate DMA channel and flush
* fifo for the next transfer if DMA thansfer timeout.
* handle_err() was called by core if transfer failed.
* Maybe it is reasonable for error handling here.
*/
if (rs->use_dma) {
if (rs->state & RXBUSY) {
dmaengine_terminate_async(rs->dma_rx.ch);
flush_fifo(rs);
}
if (atomic_read(&rs->state) & TXDMA)
dmaengine_terminate_async(rs->dma_tx.ch);
if (rs->state & TXBUSY)
dmaengine_terminate_async(rs->dma_tx.ch);
if (atomic_read(&rs->state) & RXDMA) {
dmaengine_terminate_async(rs->dma_rx.ch);
flush_fifo(rs);
}
spin_unlock_irqrestore(&rs->lock, flags);
}
static int rockchip_spi_unprepare_message(struct spi_master *master,
@ -398,48 +391,36 @@ static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
static void rockchip_spi_dma_rxcb(void *data)
{
unsigned long flags;
struct rockchip_spi *rs = data;
int state = atomic_fetch_andnot(RXDMA, &rs->state);
spin_lock_irqsave(&rs->lock, flags);
if (state & TXDMA)
return;
rs->state &= ~RXBUSY;
if (!(rs->state & TXBUSY)) {
spi_enable_chip(rs, false);
spi_finalize_current_transfer(rs->master);
}
spin_unlock_irqrestore(&rs->lock, flags);
spi_enable_chip(rs, false);
spi_finalize_current_transfer(rs->master);
}
static void rockchip_spi_dma_txcb(void *data)
{
unsigned long flags;
struct rockchip_spi *rs = data;
int state = atomic_fetch_andnot(TXDMA, &rs->state);
if (state & RXDMA)
return;
/* Wait until the FIFO data completely. */
wait_for_idle(rs);
spin_lock_irqsave(&rs->lock, flags);
rs->state &= ~TXBUSY;
if (!(rs->state & RXBUSY)) {
spi_enable_chip(rs, false);
spi_finalize_current_transfer(rs->master);
}
spin_unlock_irqrestore(&rs->lock, flags);
spi_enable_chip(rs, false);
spi_finalize_current_transfer(rs->master);
}
static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
{
unsigned long flags;
struct dma_async_tx_descriptor *rxdesc, *txdesc;
spin_lock_irqsave(&rs->lock, flags);
rs->state &= ~RXBUSY;
rs->state &= ~TXBUSY;
spin_unlock_irqrestore(&rs->lock, flags);
atomic_set(&rs->state, 0);
rxdesc = NULL;
if (rs->rx) {
@ -490,9 +471,7 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
/* rx must be started before tx due to spi instinct */
if (rxdesc) {
spin_lock_irqsave(&rs->lock, flags);
rs->state |= RXBUSY;
spin_unlock_irqrestore(&rs->lock, flags);
atomic_or(RXDMA, &rs->state);
dmaengine_submit(rxdesc);
dma_async_issue_pending(rs->dma_rx.ch);
}
@ -500,9 +479,7 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
spi_enable_chip(rs, true);
if (txdesc) {
spin_lock_irqsave(&rs->lock, flags);
rs->state |= TXBUSY;
spin_unlock_irqrestore(&rs->lock, flags);
atomic_or(TXDMA, &rs->state);
dmaengine_submit(txdesc);
dma_async_issue_pending(rs->dma_tx.ch);
}
@ -716,8 +693,6 @@ static int rockchip_spi_probe(struct platform_device *pdev)
goto err_disable_spiclk;
}
spin_lock_init(&rs->lock);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);