[net-next,v5,3/3] net: ethernet: ti: am65-cpsw: Add support for SERDES configuration

Message ID 20221109042203.375042-4-s-vadapalli@ti.com
State New
Headers
Series Add support for QSGMII mode for J721e CPSW9G to am65-cpsw driver |

Commit Message

Siddharth Vadapalli Nov. 9, 2022, 4:22 a.m. UTC
  Use PHY framework APIs to initialize the SERDES PHY connected to CPSW MAC.

Define the functions am65_cpsw_disable_phy(), am65_cpsw_enable_phy(),
am65_cpsw_disable_serdes_phy() and am65_cpsw_enable_serdes_phy().

Power on and initialize the SerDes PHY in am65_cpsw_nuss_init_slave_ports()
by invoking am65_cpsw_enable_serdes_phy().

Power off the SerDes PHY in am65_cpsw_nuss_remove() by invoking
am65_cpsw_disable_serdes_phy().

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 65 ++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
  

Comments

Paolo Abeni Nov. 10, 2022, 1:06 p.m. UTC | #1
hello,

On Wed, 2022-11-09 at 09:52 +0530, Siddharth Vadapalli wrote:
[...]

> +static void am65_cpsw_disable_serdes_phy(struct am65_cpsw_common *common)
> +{
> +	struct device_node *node, *port_np;
> +	struct device *dev = common->dev;
> +	const char *name = "serdes-phy";
> +	struct phy *phy;
> +
> +	node = of_get_child_by_name(dev->of_node, "ethernet-ports");
> +
> +	for_each_child_of_node(node, port_np) {
> +		phy = devm_of_phy_get(dev, port_np, name);

The above will try to allocate some memory and can fail. Even if the
the following code will handle a NULL ptr, the phy will not be
disabled.

I think it's better if you cache the serdes phy ptr in
am65_cpsw_init_serdes_phy() and you use such reference here, without
resorting to devm_of_phy_get().

Cheers,

Paolo
  
Siddharth Vadapalli Nov. 17, 2022, 10:16 a.m. UTC | #2
Hello Paolo,

On 10/11/22 18:36, Paolo Abeni wrote:
> hello,
> 
> On Wed, 2022-11-09 at 09:52 +0530, Siddharth Vadapalli wrote:
> [...]
> 
>> +static void am65_cpsw_disable_serdes_phy(struct am65_cpsw_common *common)
>> +{
>> +	struct device_node *node, *port_np;
>> +	struct device *dev = common->dev;
>> +	const char *name = "serdes-phy";
>> +	struct phy *phy;
>> +
>> +	node = of_get_child_by_name(dev->of_node, "ethernet-ports");
>> +
>> +	for_each_child_of_node(node, port_np) {
>> +		phy = devm_of_phy_get(dev, port_np, name);
> 
> The above will try to allocate some memory and can fail. Even if the
> the following code will handle a NULL ptr, the phy will not be
> disabled.
> 
> I think it's better if you cache the serdes phy ptr in
> am65_cpsw_init_serdes_phy() and you use such reference here, without
> resorting to devm_of_phy_get().

Thank you for reviewing the patch. I plan on creating a new "struct
phy*" member named "serdes_phy" in the struct "am65_cpsw_slave_data"
defined in the file "am65-cpsw-nuss.h", and store the SerDes phy in this
member, during the execution of the am65_cpsw_init_serdes_phy()
function. Please let me know if I can proceed with this implementation.

Regards,
Siddharth.
  

Patch

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index bc9f29d10c22..83349d24a0e6 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -1444,6 +1444,65 @@  static const struct net_device_ops am65_cpsw_nuss_netdev_ops = {
 	.ndo_setup_tc           = am65_cpsw_qos_ndo_setup_tc,
 };
 
+static void am65_cpsw_disable_phy(struct phy *phy)
+{
+	phy_power_off(phy);
+	phy_exit(phy);
+}
+
+static int am65_cpsw_enable_phy(struct phy *phy)
+{
+	int ret;
+
+	ret = phy_init(phy);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_power_on(phy);
+	if (ret < 0) {
+		phy_exit(phy);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void am65_cpsw_disable_serdes_phy(struct am65_cpsw_common *common)
+{
+	struct device_node *node, *port_np;
+	struct device *dev = common->dev;
+	const char *name = "serdes-phy";
+	struct phy *phy;
+
+	node = of_get_child_by_name(dev->of_node, "ethernet-ports");
+
+	for_each_child_of_node(node, port_np) {
+		phy = devm_of_phy_get(dev, port_np, name);
+		am65_cpsw_disable_phy(phy);
+	}
+}
+
+static int am65_cpsw_init_serdes_phy(struct device *dev, struct device_node *port_np)
+{
+	const char *name = "serdes-phy";
+	struct phy *phy;
+	int ret;
+
+	phy = devm_of_phy_get(dev, port_np, name);
+	if (PTR_ERR(phy) == -ENODEV)
+		return 0;
+
+	ret =  am65_cpsw_enable_phy(phy);
+	if (ret < 0)
+		goto err_phy;
+
+	return 0;
+
+err_phy:
+	devm_phy_put(dev, phy);
+	return ret;
+}
+
 static void am65_cpsw_nuss_mac_config(struct phylink_config *config, unsigned int mode,
 				      const struct phylink_link_state *state)
 {
@@ -1941,6 +2000,11 @@  static int am65_cpsw_nuss_init_slave_ports(struct am65_cpsw_common *common)
 			goto of_node_put;
 		}
 
+		/* Initialize the phy for the port */
+		ret = am65_cpsw_init_serdes_phy(dev, port_np);
+		if (ret)
+			return ret;
+
 		port->slave.mac_only =
 				of_property_read_bool(port_np, "ti,mac-only");
 
@@ -2868,6 +2932,7 @@  static int am65_cpsw_nuss_remove(struct platform_device *pdev)
 
 	am65_cpsw_nuss_phylink_cleanup(common);
 	am65_cpsw_unregister_devlink(common);
+	am65_cpsw_disable_serdes_phy(common);
 	am65_cpsw_unregister_notifiers(common);
 
 	/* must unregister ndevs here because DD release_driver routine calls