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net: phy: mdio-bcm-unimac: Allow configuring MDIO clock divider

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Allow the configuration of the MDIO clock divider when the Device Tree
contains 'clock-frequency' property (similar to I2C and SPI buses).
Because the hardware may have lost its state during suspend/resume,
re-apply the MDIO clock divider upon resumption.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Fainelli
2018-09-20 17:05:40 -07:00
committed by David S. Miller
parent 94e7c84499
commit b78ac6ecd1
2 changed files with 84 additions and 2 deletions
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83
drivers/net/phy/mdio-bcm-unimac.c
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@@ -16,6 +16,7 @@
#include <linux/module.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_platform.h>
@@ -45,6 +46,8 @@ struct unimac_mdio_priv {
void __iomem *base;
int (*wait_func) (void *wait_func_data);
void *wait_func_data;
struct clk *clk;
u32 clk_freq;
};
static inline u32 unimac_mdio_readl(struct unimac_mdio_priv *priv, u32 offset)
@@ -189,6 +192,35 @@ static int unimac_mdio_reset(struct mii_bus *bus)
return 0;
}
static void unimac_mdio_clk_set(struct unimac_mdio_priv *priv)
{
unsigned long rate;
u32 reg, div;
/* Keep the hardware default values */
if (!priv->clk_freq)
return;
if (!priv->clk)
rate = 250000000;
else
rate = clk_get_rate(priv->clk);
div = (rate / (2 * priv->clk_freq)) - 1;
if (div & ~MDIO_CLK_DIV_MASK) {
pr_warn("Incorrect MDIO clock frequency, ignoring\n");
return;
}
/* The MDIO clock is the reference clock (typicaly 250Mhz) divided by
* 2 x (MDIO_CLK_DIV + 1)
*/
reg = unimac_mdio_readl(priv, MDIO_CFG);
reg &= ~(MDIO_CLK_DIV_MASK << MDIO_CLK_DIV_SHIFT);
reg |= div << MDIO_CLK_DIV_SHIFT;
unimac_mdio_writel(priv, reg, MDIO_CFG);
}
static int unimac_mdio_probe(struct platform_device *pdev)
{
struct unimac_mdio_pdata *pdata = pdev->dev.platform_data;
@@ -217,9 +249,26 @@ static int unimac_mdio_probe(struct platform_device *pdev)
return -ENOMEM;
}
priv->clk = devm_clk_get(&pdev->dev, NULL);
if (PTR_ERR(priv->clk) == -EPROBE_DEFER)
return PTR_ERR(priv->clk);
else
priv->clk = NULL;
ret = clk_prepare_enable(priv->clk);
if (ret)
return ret;
if (of_property_read_u32(np, "clock-frequency", &priv->clk_freq))
priv->clk_freq = 0;
unimac_mdio_clk_set(priv);
priv->mii_bus = mdiobus_alloc();
if (!priv->mii_bus)
return -ENOMEM;
if (!priv->mii_bus) {
ret = -ENOMEM;
goto out_clk_disable;
}
bus = priv->mii_bus;
bus->priv = priv;
@@ -253,6 +302,8 @@ static int unimac_mdio_probe(struct platform_device *pdev)
out_mdio_free:
mdiobus_free(bus);
out_clk_disable:
clk_disable_unprepare(priv->clk);
return ret;
}
@@ -262,10 +313,37 @@ static int unimac_mdio_remove(struct platform_device *pdev)
mdiobus_unregister(priv->mii_bus);
mdiobus_free(priv->mii_bus);
clk_disable_unprepare(priv->clk);
return 0;
}
static int unimac_mdio_suspend(struct device *d)
{
struct unimac_mdio_priv *priv = dev_get_drvdata(d);
clk_disable_unprepare(priv->clk);
return 0;
}
static int unimac_mdio_resume(struct device *d)
{
struct unimac_mdio_priv *priv = dev_get_drvdata(d);
int ret;
ret = clk_prepare_enable(priv->clk);
if (ret)
return ret;
unimac_mdio_clk_set(priv);
return 0;
}
static SIMPLE_DEV_PM_OPS(unimac_mdio_pm_ops,
unimac_mdio_suspend, unimac_mdio_resume);
static const struct of_device_id unimac_mdio_ids[] = {
{ .compatible = "brcm,genet-mdio-v5", },
{ .compatible = "brcm,genet-mdio-v4", },
@@ -281,6 +359,7 @@ static struct platform_driver unimac_mdio_driver = {
.driver = {
.name = UNIMAC_MDIO_DRV_NAME,
.of_match_table = unimac_mdio_ids,
.pm = &unimac_mdio_pm_ops,
},
.probe = unimac_mdio_probe,
.remove = unimac_mdio_remove,