net: fec: Ensure clocks are enabled while using mdio bus
When a switch is attached to the mdio bus, the mdio bus can be used
while the interface is not open. If the IPG clock is not enabled, MDIO
reads/writes will simply time out.
Add support for runtime PM to control this clock. Enable/disable this
clock using runtime PM, with open()/close() and mdio read()/write()
function triggering runtime PM operations. Since PM is optional, the
IPG clock is enabled at probe and is no longer modified by
fec_enet_clk_enable(), thus if PM is not enabled in the kernel, it is
guaranteed the clock is running when MDIO operations are performed.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Cc: tyler.baker@linaro.org
Cc: fabio.estevam@freescale.com
Cc: shawn.guo@linaro.org
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 5e8b837..32e3807c 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -24,6 +24,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
+#include <linux/pm_runtime.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
@@ -77,6 +78,7 @@
#define FEC_ENET_RAEM_V 0x8
#define FEC_ENET_RAFL_V 0x8
#define FEC_ENET_OPD_V 0xFFF0
+#define FEC_MDIO_PM_TIMEOUT 100 /* ms */
static struct platform_device_id fec_devtype[] = {
{
@@ -1767,7 +1769,13 @@
static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
{
struct fec_enet_private *fep = bus->priv;
+ struct device *dev = &fep->pdev->dev;
unsigned long time_left;
+ int ret = 0;
+
+ ret = pm_runtime_get_sync(dev);
+ if (IS_ERR_VALUE(ret))
+ return ret;
fep->mii_timeout = 0;
init_completion(&fep->mdio_done);
@@ -1783,18 +1791,30 @@
if (time_left == 0) {
fep->mii_timeout = 1;
netdev_err(fep->netdev, "MDIO read timeout\n");
- return -ETIMEDOUT;
+ ret = -ETIMEDOUT;
+ goto out;
}
- /* return value */
- return FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA));
+ ret = FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA));
+
+out:
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ return ret;
}
static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
u16 value)
{
struct fec_enet_private *fep = bus->priv;
+ struct device *dev = &fep->pdev->dev;
unsigned long time_left;
+ int ret = 0;
+
+ ret = pm_runtime_get_sync(dev);
+ if (IS_ERR_VALUE(ret))
+ return ret;
fep->mii_timeout = 0;
init_completion(&fep->mdio_done);
@@ -1811,10 +1831,13 @@
if (time_left == 0) {
fep->mii_timeout = 1;
netdev_err(fep->netdev, "MDIO write timeout\n");
- return -ETIMEDOUT;
+ ret = -ETIMEDOUT;
}
- return 0;
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ return ret;
}
static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
@@ -1826,9 +1849,6 @@
ret = clk_prepare_enable(fep->clk_ahb);
if (ret)
return ret;
- ret = clk_prepare_enable(fep->clk_ipg);
- if (ret)
- goto failed_clk_ipg;
if (fep->clk_enet_out) {
ret = clk_prepare_enable(fep->clk_enet_out);
if (ret)
@@ -1852,7 +1872,6 @@
}
} else {
clk_disable_unprepare(fep->clk_ahb);
- clk_disable_unprepare(fep->clk_ipg);
if (fep->clk_enet_out)
clk_disable_unprepare(fep->clk_enet_out);
if (fep->clk_ptp) {
@@ -1874,8 +1893,6 @@
if (fep->clk_enet_out)
clk_disable_unprepare(fep->clk_enet_out);
failed_clk_enet_out:
- clk_disable_unprepare(fep->clk_ipg);
-failed_clk_ipg:
clk_disable_unprepare(fep->clk_ahb);
return ret;
@@ -2847,10 +2864,14 @@
struct fec_enet_private *fep = netdev_priv(ndev);
int ret;
+ ret = pm_runtime_get_sync(&fep->pdev->dev);
+ if (IS_ERR_VALUE(ret))
+ return ret;
+
pinctrl_pm_select_default_state(&fep->pdev->dev);
ret = fec_enet_clk_enable(ndev, true);
if (ret)
- return ret;
+ goto clk_enable;
/* I should reset the ring buffers here, but I don't yet know
* a simple way to do that.
@@ -2881,6 +2902,9 @@
fec_enet_free_buffers(ndev);
err_enet_alloc:
fec_enet_clk_enable(ndev, false);
+clk_enable:
+ pm_runtime_mark_last_busy(&fep->pdev->dev);
+ pm_runtime_put_autosuspend(&fep->pdev->dev);
pinctrl_pm_select_sleep_state(&fep->pdev->dev);
return ret;
}
@@ -2903,6 +2927,9 @@
fec_enet_clk_enable(ndev, false);
pinctrl_pm_select_sleep_state(&fep->pdev->dev);
+ pm_runtime_mark_last_busy(&fep->pdev->dev);
+ pm_runtime_put_autosuspend(&fep->pdev->dev);
+
fec_enet_free_buffers(ndev);
return 0;
@@ -3388,6 +3415,10 @@
if (ret)
goto failed_clk;
+ ret = clk_prepare_enable(fep->clk_ipg);
+ if (ret)
+ goto failed_clk_ipg;
+
fep->reg_phy = devm_regulator_get(&pdev->dev, "phy");
if (!IS_ERR(fep->reg_phy)) {
ret = regulator_enable(fep->reg_phy);
@@ -3400,6 +3431,11 @@
fep->reg_phy = NULL;
}
+ pm_runtime_set_autosuspend_delay(&pdev->dev, FEC_MDIO_PM_TIMEOUT);
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
fec_reset_phy(pdev);
if (fep->bufdesc_ex)
@@ -3447,6 +3483,10 @@
fep->rx_copybreak = COPYBREAK_DEFAULT;
INIT_WORK(&fep->tx_timeout_work, fec_enet_timeout_work);
+
+ pm_runtime_mark_last_busy(&pdev->dev);
+ pm_runtime_put_autosuspend(&pdev->dev);
+
return 0;
failed_register:
@@ -3458,6 +3498,8 @@
if (fep->reg_phy)
regulator_disable(fep->reg_phy);
failed_regulator:
+ clk_disable_unprepare(fep->clk_ipg);
+failed_clk_ipg:
fec_enet_clk_enable(ndev, false);
failed_clk:
failed_phy:
@@ -3567,7 +3609,28 @@
return ret;
}
-static SIMPLE_DEV_PM_OPS(fec_pm_ops, fec_suspend, fec_resume);
+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_ipg);
+
+ return 0;
+}
+
+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);
+
+ return clk_prepare_enable(fep->clk_ipg);
+}
+
+static const struct dev_pm_ops fec_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(fec_suspend, fec_resume)
+ SET_RUNTIME_PM_OPS(fec_runtime_suspend, fec_runtime_resume, NULL)
+};
static struct platform_driver fec_driver = {
.driver = {