Unverified Commit fab3e487 authored by Emil Renner Berthing's avatar Emil Renner Berthing Committed by Mark Brown
Browse files

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: default avatarEmil Renner Berthing <kernel@esmil.dk>
Tested-by: default avatarHeiko Stuebner <heiko@sntech.de>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 2410d6a3

drivers/spi/spi-rockchip.c

+25 −50
Original line number Diff line number Diff line
@@ -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) {

	if (atomic_read(&rs->state) & TXDMA)

		dmaengine_terminate_async(rs->dma_tx.ch);



	if (atomic_read(&rs->state) & RXDMA) {

		dmaengine_terminate_async(rs->dma_rx.ch);

		flush_fifo(rs);

	}



		if (rs->state & TXBUSY)

			dmaengine_terminate_async(rs->dma_tx.ch);

	}



	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);

}



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);

}



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);

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