Re: [net-next PATCH v1 6/7] net: dpaa2-mac: Add ACPI support for DPAA2 MAC driver

From: Grant Likely <grant.likely@arm.com>
To: Calvin Johnson <calvin.johnson@oss.nxp.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Jeremy Linton <jeremy.linton@arm.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Russell King - ARM Linux admin <linux@armlinux.org.uk>,
	Cristi Sovaiala <cristian.sovaiala@nxp.com>,
	Florin Laurentiu Chiculita <florinlaurentiu.chiculita@nxp.com>,
	Ioana Ciornei <ioana.ciornei@nxp.com>,
	Madalin Bucur <madalin.bucur@oss.nxp.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, linux.cj@gmail.com,
	netdev@vger.kernel.org, linux-acpi@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Diana Madalina Craciun <diana.craciun@nxp.com>,
	Laurentiu Tudor <laurentiu.tudor@nxp.com>,
	"David S. Miller" <davem@davemloft.net>,
	Ioana Radulescu <ruxandra.radulescu@nxp.com>,
	Jakub Kicinski <kuba@kernel.org>
Subject: Re: [net-next PATCH v1 6/7] net: dpaa2-mac: Add ACPI support for DPAA2 MAC driver
Date: Fri, 2 Oct 2020 12:22:37 +0100	[thread overview]
Message-ID: <0e433de7-f569-0373-59a7-16f2999902d4@arm.com> (raw)
In-Reply-To: <20200930160430.7908-7-calvin.johnson@oss.nxp.com>

On 30/09/2020 17:04, Calvin Johnson wrote:
> Modify dpaa2_mac_connect() to support ACPI along with DT.
> Modify dpaa2_mac_get_node() to get the dpmac fwnode from either
> DT or ACPI.
> 
> Replace of_get_phy_mode with fwnode_get_phy_mode to get
> phy-mode for a dpmac_node.
> 
> Use helper function phylink_fwnode_phy_connect() to find phy_dev and
> connect to mac->phylink.
> 
> Signed-off-by: Calvin Johnson <calvin.johnson@oss.nxp.com>
> ---
> 
>   .../net/ethernet/freescale/dpaa2/dpaa2-mac.c  | 79 ++++++++++++-------
>   1 file changed, 50 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c
> index 90cd243070d7..18502ee83e46 100644
> --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c
> +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c
> @@ -3,6 +3,7 @@
>   
>   #include "dpaa2-eth.h"
>   #include "dpaa2-mac.h"
> +#include <linux/acpi.h>
>   
>   #define phylink_to_dpaa2_mac(config) \
>   	container_of((config), struct dpaa2_mac, phylink_config)
> @@ -35,38 +36,56 @@ static int phy_mode(enum dpmac_eth_if eth_if, phy_interface_t *if_mode)
>   }
>   
>   /* Caller must call of_node_put on the returned value */
> -static struct device_node *dpaa2_mac_get_node(u16 dpmac_id)
> +static struct fwnode_handle *dpaa2_mac_get_node(struct device *dev,
> +						u16 dpmac_id)
>   {
> -	struct device_node *dpmacs, *dpmac = NULL;
> -	u32 id;
> +	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> +	struct fwnode_handle *dpmacs, *dpmac = NULL;
> +	unsigned long long adr;
> +	acpi_status status;
>   	int err;
> +	u32 id;
>   
> -	dpmacs = of_find_node_by_name(NULL, "dpmacs");
> -	if (!dpmacs)
> -		return NULL;
> +	if (is_of_node(dev->parent->fwnode)) {
> +		dpmacs = device_get_named_child_node(dev->parent, "dpmacs");
> +		if (!dpmacs)
> +			return NULL;
> +
> +		while ((dpmac = fwnode_get_next_child_node(dpmacs, dpmac))) {
> +			err = fwnode_property_read_u32(dpmac, "reg", &id);
> +			if (err)
> +				continue;
> +			if (id == dpmac_id)
> +				return dpmac;
> +		}
There is a change of behaviour here that isn't described in the patch 
description, so I'm having trouble following the intent. The original 
code searches the tree for a node named "dpmacs", but the new code 
constrains the search to just the parent device.

Also, because the new code path is only used in the DT case, I don't see 
why the behaviour change is required. If it is a bug fix, it should be 
broken out into a separate patch. If it is something else, can you 
describe what the reasoning is?

I also see that the change to the code has dropped the of_node_put() on 
the exit path.

>   
> -	while ((dpmac = of_get_next_child(dpmacs, dpmac)) != NULL) {
> -		err = of_property_read_u32(dpmac, "reg", &id);
> -		if (err)
> -			continue;
> -		if (id == dpmac_id)
> -			break;
> +	} else if (is_acpi_node(dev->parent->fwnode)) {
> +		device_for_each_child_node(dev->parent, dpmac) {
> +			status = acpi_evaluate_integer(ACPI_HANDLE_FWNODE(dpmac),
> +						       "_ADR", NULL, &adr);
> +			if (ACPI_FAILURE(status)) {
> +				pr_debug("_ADR returned %d on %s\n",
> +					 status, (char *)buffer.pointer);
> +				continue;
> +			} else {
> +				id = (u32)adr;
> +				if (id == dpmac_id)
> +					return dpmac;
> +			}
> +		}
>   	}
> -
> -	of_node_put(dpmacs);
> -
> -	return dpmac;
> +	return NULL;
>   }
>   
> -static int dpaa2_mac_get_if_mode(struct device_node *node,
> +static int dpaa2_mac_get_if_mode(struct fwnode_handle *dpmac_node,
>   				 struct dpmac_attr attr)
>   {
>   	phy_interface_t if_mode;
>   	int err;
>   
> -	err = of_get_phy_mode(node, &if_mode);
> -	if (!err)
> -		return if_mode;
> +	err = fwnode_get_phy_mode(dpmac_node);
> +	if (err > 0)
> +		return err;

Is this correct? The function prototype from patch 2 is:

struct fwnode_handle *fwnode_get_phy_node(struct fwnode_handle *fwnode)

It returns struct fwnode_handle *. Does this compile?

>   
>   	err = phy_mode(attr.eth_if, &if_mode);
>   	if (!err)
> @@ -303,7 +322,7 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>   {
>   	struct fsl_mc_device *dpmac_dev = mac->mc_dev;
>   	struct net_device *net_dev = mac->net_dev;
> -	struct device_node *dpmac_node;
> +	struct fwnode_handle *dpmac_node = NULL;
>   	struct phylink *phylink;
>   	struct dpmac_attr attr;
>   	int err;
> @@ -323,7 +342,7 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>   
>   	mac->if_link_type = attr.link_type;
>   
> -	dpmac_node = dpaa2_mac_get_node(attr.id);
> +	dpmac_node = dpaa2_mac_get_node(&mac->mc_dev->dev, attr.id);
>   	if (!dpmac_node) {
>   		netdev_err(net_dev, "No dpmac@%d node found.\n", attr.id);
>   		err = -ENODEV;
> @@ -341,7 +360,7 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>   	 * error out if the interface mode requests them and there is no PHY
>   	 * to act upon them
>   	 */
> -	if (of_phy_is_fixed_link(dpmac_node) &&
> +	if (of_phy_is_fixed_link(to_of_node(dpmac_node)) &&
>   	    (mac->if_mode == PHY_INTERFACE_MODE_RGMII_ID ||
>   	     mac->if_mode == PHY_INTERFACE_MODE_RGMII_RXID ||
>   	     mac->if_mode == PHY_INTERFACE_MODE_RGMII_TXID)) {
> @@ -352,7 +371,7 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>   
>   	if (attr.link_type == DPMAC_LINK_TYPE_PHY &&
>   	    attr.eth_if != DPMAC_ETH_IF_RGMII) {
> -		err = dpaa2_pcs_create(mac, dpmac_node, attr.id);
> +		err = dpaa2_pcs_create(mac, to_of_node(dpmac_node), attr.id);
>   		if (err)
>   			goto err_put_node;
>   	}
> @@ -361,7 +380,7 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>   	mac->phylink_config.type = PHYLINK_NETDEV;
>   
>   	phylink = phylink_create(&mac->phylink_config,
> -				 of_fwnode_handle(dpmac_node), mac->if_mode,
> +				 dpmac_node, mac->if_mode,
>   				 &dpaa2_mac_phylink_ops);
>   	if (IS_ERR(phylink)) {
>   		err = PTR_ERR(phylink);
> @@ -372,13 +391,14 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>   	if (mac->pcs)
>   		phylink_set_pcs(mac->phylink, &mac->pcs->pcs);
>   
> -	err = phylink_of_phy_connect(mac->phylink, dpmac_node, 0);
> +	err = phylink_fwnode_phy_connect(mac->phylink, dpmac_node, 0);
>   	if (err) {
> -		netdev_err(net_dev, "phylink_of_phy_connect() = %d\n", err);
> +		netdev_err(net_dev, "phylink_fwnode_phy_connect() = %d\n", err);
>   		goto err_phylink_destroy;
>   	}
>   
> -	of_node_put(dpmac_node);
> +	if (is_of_node(dpmac_node))
> +		of_node_put(to_of_node(dpmac_node));
>   
>   	return 0;
>   
> @@ -387,7 +407,8 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
>   err_pcs_destroy:
>   	dpaa2_pcs_destroy(mac);
>   err_put_node:
> -	of_node_put(dpmac_node);
> +	if (is_of_node(dpmac_node))
> +		of_node_put(to_of_node(dpmac_node));
>   err_close_dpmac:
>   	dpmac_close(mac->mc_io, 0, dpmac_dev->mc_handle);
>   	return err;
> 