From fab3e4871f623c8f86e8a0e00749f1480ffa08db Mon Sep 17 00:00:00 2001 From: Emil Renner Berthing Date: Wed, 31 Oct 2018 11:57:01 +0100 Subject: 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 Tested-by: Heiko Stuebner Signed-off-by: Mark Brown --- drivers/spi/spi-rockchip.c | 75 ++++++++++++++++------------------------------ 1 file changed, 25 insertions(+), 50 deletions(-) (limited to 'drivers/spi/spi-rockchip.c') diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 7fac4253075e..1c813797f963 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -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); - - rs->state &= ~RXBUSY; - if (!(rs->state & TXBUSY)) { - spi_enable_chip(rs, false); - spi_finalize_current_transfer(rs->master); - } + if (state & TXDMA) + return; - 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); -- cgit v1.2.3