Commit 61499764 authored by Russell King (Oracle)'s avatar Russell King (Oracle) Committed by David S. Miller
Browse files

net: stmmac: stm32: simplify clock handling 



Some stm32 implementations need the receive clock running in suspend,
as indicated by dwmac->ops->clk_rx_enable_in_suspend. The existing
code achieved this in a rather complex way, by passing a flag around.

However, the clk API prepare/enables are counted - which means that a
clock won't be stopped as long as there are more prepare and enables
than disables and unprepares, just like a reference count.

Therefore, we can simplify this logic by calling clk_prepare_enable()
an additional time in the probe function if this flag is set, and then
balancing that at remove time.

With this, we can avoid passing a "are we suspending" and "are we
resuming" flag to various functions in the driver.

Signed-off-by: default avatarRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0c49baf0

drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c

+37 −20
Original line number Diff line number Diff line
@@ -119,7 +119,7 @@ struct stm32_ops { 
	u32 syscfg_clr_off;

};



static int stm32_dwmac_clk_enable(struct stm32_dwmac *dwmac, bool resume)

static int stm32_dwmac_clk_enable(struct stm32_dwmac *dwmac)

{

	int ret;
@@ -127,11 +127,9 @@ static int stm32_dwmac_clk_enable(struct stm32_dwmac *dwmac, bool resume) 
	if (ret)

		goto err_clk_tx;



	if (!dwmac->ops->clk_rx_enable_in_suspend || !resume) {

	ret = clk_prepare_enable(dwmac->clk_rx);

	if (ret)

		goto err_clk_rx;

	}



	ret = clk_prepare_enable(dwmac->syscfg_clk);

	if (ret)
@@ -148,7 +146,6 @@ static int stm32_dwmac_clk_enable(struct stm32_dwmac *dwmac, bool resume) 
err_clk_eth_ck:

	clk_disable_unprepare(dwmac->syscfg_clk);

err_syscfg_clk:

	if (!dwmac->ops->clk_rx_enable_in_suspend || !resume)

	clk_disable_unprepare(dwmac->clk_rx);

err_clk_rx:

	clk_disable_unprepare(dwmac->clk_tx);
@@ -156,7 +153,7 @@ static int stm32_dwmac_clk_enable(struct stm32_dwmac *dwmac, bool resume) 
	return ret;

}



static int stm32_dwmac_init(struct plat_stmmacenet_data *plat_dat, bool resume)

static int stm32_dwmac_init(struct plat_stmmacenet_data *plat_dat)

{

	struct stm32_dwmac *dwmac = plat_dat->bsp_priv;

	int ret;
@@ -167,7 +164,7 @@ static int stm32_dwmac_init(struct plat_stmmacenet_data *plat_dat, bool resume) 
			return ret;

	}



	return stm32_dwmac_clk_enable(dwmac, resume);

	return stm32_dwmac_clk_enable(dwmac);

}



static int stm32mp1_select_ethck_external(struct plat_stmmacenet_data *plat_dat)
@@ -382,12 +379,10 @@ static int stm32mcu_set_mode(struct plat_stmmacenet_data *plat_dat) 
				 SYSCFG_MCU_ETH_MASK, val << 23);

}



static void stm32_dwmac_clk_disable(struct stm32_dwmac *dwmac, bool suspend)

static void stm32_dwmac_clk_disable(struct stm32_dwmac *dwmac)

{

	clk_disable_unprepare(dwmac->clk_tx);

	if (!dwmac->ops->clk_rx_enable_in_suspend || !suspend)

	clk_disable_unprepare(dwmac->clk_rx);



	clk_disable_unprepare(dwmac->syscfg_clk);

	if (dwmac->enable_eth_ck)

		clk_disable_unprepare(dwmac->clk_eth_ck);
@@ -541,18 +536,32 @@ static int stm32_dwmac_probe(struct platform_device *pdev) 
	plat_dat->flags |= STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP;

	plat_dat->bsp_priv = dwmac;



	ret = stm32_dwmac_init(plat_dat, false);

	ret = stm32_dwmac_init(plat_dat);

	if (ret)

		return ret;



	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);

	/* If this platform requires the clock to be running in suspend,

	 * prepare and enable the receive clock an additional time to keep

	 * it running.

	 */

	if (dwmac->ops->clk_rx_enable_in_suspend) {

		ret = clk_prepare_enable(dwmac->clk_rx);

		if (ret)

			goto err_clk_disable;

	}



	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);

	if (ret)

		goto err_clk_disable_suspend;



	return 0;



err_clk_disable_suspend:

	if (dwmac->ops->clk_rx_enable_in_suspend)

		clk_disable_unprepare(dwmac->clk_rx);



err_clk_disable:

	stm32_dwmac_clk_disable(dwmac, false);

	stm32_dwmac_clk_disable(dwmac);



	return ret;

}
@@ -565,7 +574,15 @@ static void stm32_dwmac_remove(struct platform_device *pdev) 


	stmmac_dvr_remove(&pdev->dev);



	stm32_dwmac_clk_disable(dwmac, false);

	/* If this platform requires the clock to be running in suspend,

	 * we need to disable and unprepare the receive clock an additional

	 * time to balance the extra clk_prepare_enable() in the probe

	 * function.

	 */

	if (dwmac->ops->clk_rx_enable_in_suspend)

		clk_disable_unprepare(dwmac->clk_rx);



	stm32_dwmac_clk_disable(dwmac);



	if (dwmac->irq_pwr_wakeup >= 0) {

		dev_pm_clear_wake_irq(&pdev->dev);
@@ -596,7 +613,7 @@ static int stm32_dwmac_suspend(struct device *dev) 
	if (ret)

		return ret;



	stm32_dwmac_clk_disable(dwmac, true);

	stm32_dwmac_clk_disable(dwmac);



	if (dwmac->ops->suspend)

		ret = dwmac->ops->suspend(dwmac);
@@ -614,7 +631,7 @@ static int stm32_dwmac_resume(struct device *dev) 
	if (dwmac->ops->resume)

		dwmac->ops->resume(dwmac);



	ret = stm32_dwmac_init(priv->plat, true);

	ret = stm32_dwmac_init(priv->plat);

	if (ret)

		return ret;