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net: stmmac: stm32: simplify clock handling

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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: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Russell King (Oracle)
2025-04-07 20:15:35 +01:00
committed by David S. Miller
parent 0c49baf099
commit 61499764e5
1 changed files with 37 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

57
drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
View File

@@ -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->clk_rx);
if (ret)
goto err_clk_rx;
ret = clk_prepare_enable(dwmac->syscfg_clk);
if (ret)
@@ -148,15 +146,14 @@ 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);
clk_disable_unprepare(dwmac->clk_rx);
err_clk_rx:
clk_disable_unprepare(dwmac->clk_tx);
err_clk_tx:
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->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;
/* 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;
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;