[PATCH 5.0 006/115] net: fec: manage ahb clock in runtime pm

From: Greg Kroah-Hartman
Date: Wed Apr 24 2019 - 13:34:23 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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/freescale/fec_main.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1840,13 +1840,9 @@ static int fec_enet_clk_enable(struct ne
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);
@@ -1866,7 +1862,6 @@ static int fec_enet_clk_enable(struct ne

phy_reset_after_clk_enable(ndev->phydev);
} else {
- clk_disable_unprepare(fep->clk_ahb);
clk_disable_unprepare(fep->clk_enet_out);
if (fep->clk_ptp) {
mutex_lock(&fep->ptp_clk_mutex);
@@ -1885,8 +1880,6 @@ failed_clk_ref:
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;
}
@@ -3470,6 +3463,9 @@ 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_optional(&pdev->dev, "phy");
if (!IS_ERR(fep->reg_phy)) {
@@ -3563,6 +3559,9 @@ failed_reset:
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:
@@ -3686,6 +3685,7 @@ static int __maybe_unused fec_runtime_su
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;
@@ -3695,8 +3695,20 @@ static int __maybe_unused fec_runtime_re
{
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 = {