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Commit 6c3e921b authored by Andrew Lunn's avatar Andrew Lunn Committed by David S. Miller
Browse files

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: default avatarAndrew Lunn <andrew@lunn.ch>
Acked-by: default avatarFugang Duan <B38611@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cfbfd86b

drivers/net/ethernet/freescale/fec_main.c

+75 −13
Original line number Diff line number Diff line
@@ -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 @@ static void fec_enet_itr_coal_init(struct net_device *ndev); 
#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 void fec_enet_adjust_link(struct net_device *ndev) 
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 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) 
	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 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, 
	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 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) 
		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 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) 
		}

	} 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 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) 
	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 @@ fec_enet_open(struct net_device *ndev) 
	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_open(struct net_device *ndev) 
	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_close(struct net_device *ndev) 


	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 @@ fec_probe(struct platform_device *pdev) 
	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);
@@ -3434,6 +3465,8 @@ fec_probe(struct platform_device *pdev) 
	netif_carrier_off(ndev);

	fec_enet_clk_enable(ndev, false);

	pinctrl_pm_select_sleep_state(&pdev->dev);

	pm_runtime_set_active(&pdev->dev);

	pm_runtime_enable(&pdev->dev);



	ret = register_netdev(ndev);

	if (ret)
@@ -3447,6 +3480,12 @@ fec_probe(struct platform_device *pdev) 


	fep->rx_copybreak = COPYBREAK_DEFAULT;

	INIT_WORK(&fep->tx_timeout_work, fec_enet_timeout_work);



	pm_runtime_set_autosuspend_delay(&pdev->dev, FEC_MDIO_PM_TIMEOUT);

	pm_runtime_use_autosuspend(&pdev->dev);

	pm_runtime_mark_last_busy(&pdev->dev);

	pm_runtime_put_autosuspend(&pdev->dev);



	return 0;



failed_register:
@@ -3457,6 +3496,8 @@ fec_probe(struct platform_device *pdev) 
	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:
@@ -3568,7 +3609,28 @@ static int __maybe_unused fec_resume(struct device *dev) 
	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	= {