@@ -23,6 +23,7 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/netdevice.h>
+#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/phy_led_triggers.h>
#include <linux/property.h>
@@ -2914,8 +2915,11 @@ static int phy_probe(struct device *dev)
out:
/* Assert the reset signal */
- if (err)
+ if (err) {
phy_device_reset(phydev, 1);
+ of_mdiobus_device_disable_resources(phydev->mdio.bus,
+ phydev->mdio.addr);
+ }
mutex_unlock(&phydev->lock);
@@ -19,6 +19,7 @@
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/module.h>
+#include <linux/clk.h>
#define DEFAULT_GPIO_RESET_DELAY 10 /* in microseconds */
@@ -60,6 +61,81 @@ static struct mii_timestamper *of_find_mii_timestamper(struct device_node *node)
return register_mii_timestamper(arg.np, arg.args[0]);
}
+static int of_mdiobus_device_enable_resources(struct mii_bus *bus,
+ struct device_node *child,
+ u32 addr)
+{
+ struct mdio_device_resource *res = &bus->mdio_resources[addr];
+ unsigned int i;
+ int rc;
+
+ rc = of_count_phandle_with_args(child, "clocks", "#clock-cells");
+ if (rc < 0) {
+ if (rc == -ENOENT)
+ rc = 0;
+ else
+ return rc;
+ }
+
+ res->num_clks = rc;
+ if (rc == 0)
+ return rc;
+
+ dev_dbg(&bus->dev, "Found %d clocks for child at %d\n", rc, addr);
+
+ res->clks = devm_kcalloc(&bus->dev, res->num_clks,
+ sizeof(struct clk *), GFP_KERNEL);
+ if (!res->clks)
+ return -ENOMEM;
+
+ for (i = 0; i < res->num_clks; i++) {
+ res->clks[i] = of_clk_get(child, i);
+ if (IS_ERR(res->clks[i])) {
+ if (PTR_ERR(res->clks[i]) == -ENOENT)
+ continue;
+
+ return PTR_ERR(res->clks[i]);
+ }
+
+ rc = clk_prepare_enable(res->clks[i]);
+ if (rc) {
+ dev_err(&bus->dev,
+ "Failed to enabled clock for %d (rc: %d)\n",
+ addr, rc);
+ goto out_clk_disable;
+ }
+
+ dev_dbg(&bus->dev,
+ "Enable clock %d for child at %d\n",
+ i, addr);
+ }
+
+ return 0;
+
+out_clk_disable:
+ while (i-- > 0) {
+ clk_disable_unprepare(res->clks[i]);
+ clk_put(res->clks[i]);
+ }
+ return rc;
+}
+
+void of_mdiobus_device_disable_resources(struct mii_bus *bus, u32 addr)
+{
+ struct mdio_device_resource *res = &bus->mdio_resources[addr];
+ unsigned int i;
+
+ if (res->num_clks == 0)
+ return;
+
+ for (i = 0; i < res->num_clks; i++) {
+ clk_disable_unprepare(res->clks[i]);
+ clk_put(res->clks[i]);
+ dev_dbg(&bus->dev, "Disabled clk %d for %d\n", i, addr);
+ }
+}
+EXPORT_SYMBOL(of_mdiobus_device_disable_resources);
+
int of_mdiobus_phy_device_register(struct mii_bus *mdio, struct phy_device *phy,
struct device_node *child, u32 addr)
{
@@ -117,6 +193,12 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio,
if (IS_ERR(mii_ts))
return PTR_ERR(mii_ts);
+ rc = of_mdiobus_device_enable_resources(mdio, child, addr);
+ if (rc) {
+ dev_err(&mdio->dev, "enable resources: %d\n", rc);
+ return rc;
+ }
+
is_c45 = of_device_is_compatible(child,
"ethernet-phy-ieee802.3-c45");
@@ -125,6 +207,7 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio,
else
phy = get_phy_device(mdio, addr, is_c45);
if (IS_ERR(phy)) {
+ of_mdiobus_device_disable_resources(mdio, addr);
if (mii_ts)
unregister_mii_timestamper(mii_ts);
return PTR_ERR(phy);
@@ -132,6 +215,7 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio,
rc = of_mdiobus_phy_device_register(mdio, phy, child, addr);
if (rc) {
+ of_mdiobus_device_disable_resources(mdio, addr);
if (mii_ts)
unregister_mii_timestamper(mii_ts);
phy_device_free(phy);
@@ -58,6 +58,8 @@ static inline int of_mdio_parse_addr(struct device *dev,
return addr;
}
+void of_mdiobus_device_disable_resources(struct mii_bus *mdio, u32 addr);
+
#else /* CONFIG_OF_MDIO */
static inline bool of_mdiobus_child_is_phy(struct device_node *child)
{
@@ -129,6 +131,11 @@ static inline int of_mdiobus_phy_device_register(struct mii_bus *mdio,
{
return -ENOSYS;
}
+
+static inline void of_mdiobus_device_disable_resources(struct mii_bus *mdio,
+ u32 addr)
+{
+}
#endif
@@ -247,6 +247,13 @@ struct phy_package_shared {
#define PHY_SHARED_F_INIT_DONE 0
#define PHY_SHARED_F_PROBE_DONE 1
+struct clk;
+
+struct mdio_device_resource {
+ unsigned int num_clks;
+ struct clk **clks;
+};
+
/*
* The Bus class for PHYs. Devices which provide access to
* PHYs should register using this structure
@@ -291,6 +298,11 @@ struct mii_bus {
*/
int irq[PHY_MAX_ADDR];
+ /* An array of MDIO device resources that must be enabled
+ * during probe for identification to succeed.
+ */
+ struct mdio_device_resource mdio_resources[PHY_MAX_ADDR];
+
/* GPIO reset pulse width in microseconds */
int reset_delay_us;
/* GPIO reset deassert delay in microseconds */
Some Ethernet PHYs may require that their clock, which typically drives their logic to respond to reads on the MDIO bus be enabled before issusing a MDIO bus scan. We have a chicken and egg problem though which is that we cannot enable a given Ethernet PHY's device clock until we have a phy_device instance create and called the driver's probe function. This will not happen unless we are successful in probing the PHY device, which requires its clock(s) to be turned on. For DT based systems we can solve this by using of_clk_get() which operates on a device_node reference, and make sure that all clocks associaed with the node are enabled prior to doing any reads towards the device. In order to avoid drivers having to know the a priori reference count of the resources, we drop them back to 0 right before calling ->probe() which is then supposed to manage the resources normally. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> --- drivers/net/phy/phy_device.c | 6 ++- drivers/of/of_mdio.c | 84 ++++++++++++++++++++++++++++++++++++ include/linux/of_mdio.h | 7 +++ include/linux/phy.h | 12 ++++++ 4 files changed, 108 insertions(+), 1 deletion(-)