[PATCH AUTOSEL 4.14 88/95] net: fec: manage ahb clock in runtime pm

From: Sasha Levin
Date: Tue May 07 2019 - 01:47:36 EST


From: Andy Duan <fugang.duan@xxxxxxx>

[ Upstream commit d7c3a206e6338e4ccdf030719dec028e26a521d5 ]

Some SOC like i.MX6SX clock have some limits:
- ahb clock should be disabled before ipg.
- ahb and ipg clocks are required for MAC MII bus.
So, move the ahb clock to runtime management together with
ipg clock.

Signed-off-by: Fugang Duan <fugang.duan@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
drivers/net/ethernet/freescale/fec_main.c | 30 ++++++++++++++++-------
1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index ce55c8f7f33a..ad3aabc39cc2 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1851,13 +1851,9 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
int ret;

if (enable) {
- ret = clk_prepare_enable(fep->clk_ahb);
- if (ret)
- return ret;
-
ret = clk_prepare_enable(fep->clk_enet_out);
if (ret)
- goto failed_clk_enet_out;
+ return ret;

if (fep->clk_ptp) {
mutex_lock(&fep->ptp_clk_mutex);
@@ -1875,7 +1871,6 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
if (ret)
goto failed_clk_ref;
} else {
- clk_disable_unprepare(fep->clk_ahb);
clk_disable_unprepare(fep->clk_enet_out);
if (fep->clk_ptp) {
mutex_lock(&fep->ptp_clk_mutex);
@@ -1894,8 +1889,6 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
failed_clk_ptp:
if (fep->clk_enet_out)
clk_disable_unprepare(fep->clk_enet_out);
-failed_clk_enet_out:
- clk_disable_unprepare(fep->clk_ahb);

return ret;
}
@@ -3455,6 +3448,9 @@ fec_probe(struct platform_device *pdev)
ret = clk_prepare_enable(fep->clk_ipg);
if (ret)
goto failed_clk_ipg;
+ ret = clk_prepare_enable(fep->clk_ahb);
+ if (ret)
+ goto failed_clk_ahb;

fep->reg_phy = devm_regulator_get(&pdev->dev, "phy");
if (!IS_ERR(fep->reg_phy)) {
@@ -3546,6 +3542,9 @@ fec_probe(struct platform_device *pdev)
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
failed_regulator:
+ clk_disable_unprepare(fep->clk_ahb);
+failed_clk_ahb:
+ clk_disable_unprepare(fep->clk_ipg);
failed_clk_ipg:
fec_enet_clk_enable(ndev, false);
failed_clk:
@@ -3669,6 +3668,7 @@ static int __maybe_unused fec_runtime_suspend(struct device *dev)
struct net_device *ndev = dev_get_drvdata(dev);
struct fec_enet_private *fep = netdev_priv(ndev);

+ clk_disable_unprepare(fep->clk_ahb);
clk_disable_unprepare(fep->clk_ipg);

return 0;
@@ -3678,8 +3678,20 @@ static int __maybe_unused fec_runtime_resume(struct device *dev)
{
struct net_device *ndev = dev_get_drvdata(dev);
struct fec_enet_private *fep = netdev_priv(ndev);
+ int ret;

- return clk_prepare_enable(fep->clk_ipg);
+ ret = clk_prepare_enable(fep->clk_ahb);
+ if (ret)
+ return ret;
+ ret = clk_prepare_enable(fep->clk_ipg);
+ if (ret)
+ goto failed_clk_ipg;
+
+ return 0;
+
+failed_clk_ipg:
+ clk_disable_unprepare(fep->clk_ahb);
+ return ret;
}

static const struct dev_pm_ops fec_pm_ops = {
--
2.20.1