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net: macb: Adjust tx_clk when link speed changes

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Adjust the ethernet clock according to the negotiated link speed.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Soren Brinkmann 2013-12-10 16:07:23 -08:00 • committed by David S. Miller
commit e1824dfe0d
2 changed files with 65 additions and 0 deletions
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64
drivers/net/ethernet/cadence/macb.c
View file

@ -204,6 +204,47 @@ static int macb_mdio_reset(struct mii_bus *bus)
return 0;
}
/**
* macb_set_tx_clk() - Set a clock to a new frequency
* @clk Pointer to the clock to change
* @rate New frequency in Hz
* @dev Pointer to the struct net_device
*/
static void macb_set_tx_clk(struct clk *clk, int speed, struct net_device *dev)
{
long ferr, rate, rate_rounded;
switch (speed) {
case SPEED_10:
rate = 2500000;
break;
case SPEED_100:
rate = 25000000;
break;
case SPEED_1000:
rate = 125000000;
break;
default:
break;
}
rate_rounded = clk_round_rate(clk, rate);
if (rate_rounded < 0)
return;
/* RGMII allows 50 ppm frequency error. Test and warn if this limit
* is not satisfied.
*/
ferr = abs(rate_rounded - rate);
ferr = DIV_ROUND_UP(ferr, rate / 100000);
if (ferr > 5)
netdev_warn(dev, "unable to generate target frequency: %ld Hz\n",
rate);
if (clk_set_rate(clk, rate_rounded))
netdev_err(dev, "adjusting tx_clk failed.\n");
}
static void macb_handle_link_change(struct net_device *dev)
{
struct macb *bp = netdev_priv(dev);
@ -251,6 +292,9 @@ static void macb_handle_link_change(struct net_device *dev)
spin_unlock_irqrestore(&bp->lock, flags);
if (!IS_ERR(bp->tx_clk))
macb_set_tx_clk(bp->tx_clk, phydev->speed, dev);
if (status_change) {
if (phydev->link) {
netif_carrier_on(dev);
@ -1805,6 +1849,8 @@ static int __init macb_probe(struct platform_device *pdev)
goto err_out_free_dev;
}
bp->tx_clk = devm_clk_get(&pdev->dev, "tx_clk");
err = clk_prepare_enable(bp->pclk);
if (err) {
dev_err(&pdev->dev, "failed to enable pclk (%u)\n", err);
@ -1817,6 +1863,15 @@ static int __init macb_probe(struct platform_device *pdev)
goto err_out_disable_pclk;
}
if (!IS_ERR(bp->tx_clk)) {
err = clk_prepare_enable(bp->tx_clk);
if (err) {
dev_err(&pdev->dev, "failed to enable tx_clk (%u)\n",
err);
goto err_out_disable_hclk;
}
}
bp->regs = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
if (!bp->regs) {
dev_err(&pdev->dev, "failed to map registers, aborting.\n");
@ -1917,6 +1972,9 @@ static int __init macb_probe(struct platform_device *pdev)
err_out_unregister_netdev:
unregister_netdev(dev);
err_out_disable_clocks:
if (!IS_ERR(bp->tx_clk))
clk_disable_unprepare(bp->tx_clk);
err_out_disable_hclk:
clk_disable_unprepare(bp->hclk);
err_out_disable_pclk:
clk_disable_unprepare(bp->pclk);
@ -1941,6 +1999,8 @@ static int __exit macb_remove(struct platform_device *pdev)
kfree(bp->mii_bus->irq);
mdiobus_free(bp->mii_bus);
unregister_netdev(dev);
if (!IS_ERR(bp->tx_clk))
clk_disable_unprepare(bp->tx_clk);
clk_disable_unprepare(bp->hclk);
clk_disable_unprepare(bp->pclk);
free_netdev(dev);
@ -1959,6 +2019,8 @@ static int macb_suspend(struct device *dev)
netif_carrier_off(netdev);
netif_device_detach(netdev);
if (!IS_ERR(bp->tx_clk))
clk_disable_unprepare(bp->tx_clk);
clk_disable_unprepare(bp->hclk);
clk_disable_unprepare(bp->pclk);
@ -1973,6 +2035,8 @@ static int macb_resume(struct device *dev)
clk_prepare_enable(bp->pclk);
clk_prepare_enable(bp->hclk);
if (!IS_ERR(bp->tx_clk))
clk_prepare_enable(bp->tx_clk);
netif_device_attach(netdev);

1
drivers/net/ethernet/cadence/macb.h
View file

@ -572,6 +572,7 @@ struct macb {
struct platform_device *pdev;
struct clk *pclk;
struct clk *hclk;
struct clk *tx_clk;
struct net_device *dev;
struct napi_struct napi;
struct work_struct tx_error_task;