Re: [PATCH v3 13/13] platform/x86: intel_cht_int33fe: Replacing the old connections with references

From: Hans de Goede
Date: Tue Apr 16 2019 - 17:35:49 EST


Hi,

On 12-04-19 15:41, Heikki Krogerus wrote:
Now that the software nodes support references, and the
device connection API support parsing fwnode references,
replacing the old connection descriptions with software node
references. Relying on device names when matching the
connection would not have been possible to link the USB
Type-C connector and the DisplayPort connector together, but
with real references it's not problem.

The DisplayPort ACPI node is dag up, and the drivers own
software node for the DisplayPort is set as the secondary
node for it. The USB Type-C connector refers the software
node, but it is now tied to the ACPI node, and therefore any
device entry (struct drm_connector in practice) that the
node combo is assigned to.

The USB role switch device does not have ACPI node, so we
have to wait for the device to appear. Then we can simply
assign our software node for the to the device.

Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

So as promised I've been testing this series and this commit
breaks type-c functionality on devices using this driver.

The problem is that typec_switch_get() and typec_mux_get()
after this both return the same pointer, which is pointing
to the switch, so typec_mux_get() is returning the wrong
pointer.

This is not surprising since the references for both are
both pointing to the fwnode attached to the piusb30532 devices:

args[0].fwnode = data->node[INT33FE_NODE_PI3USB30532];

So the class_find_device here:

static void *typec_switch_match(struct device_connection *con, int ep,
void *data)
{
struct device *dev;

if (con->fwnode) {
if (con->id && !fwnode_property_present(con->fwnode, con->id))
return NULL;

dev = class_find_device(&typec_mux_class, NULL, con->fwnode,
fwnode_match);
} else {
dev = class_find_device(&typec_mux_class, NULL,
con->endpoint[ep], name_match);
}

return dev ? to_typec_switch(dev) : ERR_PTR(-EPROBE_DEFER);
}

Simply returns the first typec_mux_class device registered.

I see 2 possible solutions to this problem:

1) Use separate typec_mux_class and typec_orientation_switch_class-es

2) Merge struct typec_switch and struct typec_mux into a single struct,
so that all typec_mux_class devices have the same memory layout, add
a subclass enum to this new merged struct and use that to identify
which of the typec_mux_class devices with the same fwnode pointer we
want.

Any other suggestions?

Regards,

Hans





---
drivers/platform/x86/intel_cht_int33fe.c | 93 +++++++++++++++++++-----
1 file changed, 76 insertions(+), 17 deletions(-)

diff --git a/drivers/platform/x86/intel_cht_int33fe.c b/drivers/platform/x86/intel_cht_int33fe.c
index 7711667a3454..e6a1ea7f33af 100644
--- a/drivers/platform/x86/intel_cht_int33fe.c
+++ b/drivers/platform/x86/intel_cht_int33fe.c
@@ -39,15 +39,22 @@ enum {
INT33FE_NODE_MAX,
};
+enum {
+ INT33FE_REF_ORIENTATION,
+ INT33FE_REF_MODE_MUX,
+ INT33FE_REF_DISPLAYPORT,
+ INT33FE_REF_ROLE_SWITCH,
+ INT33FE_REF_MAX,
+};
+
struct cht_int33fe_data {
struct i2c_client *max17047;
struct i2c_client *fusb302;
struct i2c_client *pi3usb30532;
- /* Contain a list-head must be per device */
- struct device_connection connections[4];
struct fwnode_handle *dp;
struct fwnode_handle *node[INT33FE_NODE_MAX];
+ struct software_node_reference *ref[INT33FE_REF_MAX];
};
/*
@@ -280,6 +287,65 @@ static int cht_int33fe_add_nodes(struct cht_int33fe_data *data)
return ret;
}
+static void cht_int33fe_remove_references(struct cht_int33fe_data *data)
+{
+ int i;
+
+ for (i = 0; i < INT33FE_REF_MAX; i++)
+ fwnode_remove_software_node_reference(data->ref[i]);
+}
+
+static int cht_int33fe_add_references(struct cht_int33fe_data *data)
+{
+ struct fwnode_reference_args args[2] = { };
+ struct software_node_reference *ref;
+ struct fwnode_handle *con;
+
+ con = data->node[INT33FE_NODE_USB_CONNECTOR];
+
+ /* USB Type-C muxes */
+ args[0].fwnode = data->node[INT33FE_NODE_PI3USB30532];
+ args[1].fwnode = NULL;
+
+ ref = fwnode_create_software_node_reference(con, "orientation-switch",
+ args);
+ if (IS_ERR(ref))
+ return PTR_ERR(ref);
+ data->ref[INT33FE_REF_ORIENTATION] = ref;
+
+ ref = fwnode_create_software_node_reference(con, "mode-switch", args);
+ if (IS_ERR(ref)) {
+ cht_int33fe_remove_references(data);
+ return PTR_ERR(ref);
+ }
+ data->ref[INT33FE_REF_MODE_MUX] = ref;
+
+ /* USB role switch */
+ args[0].fwnode = data->node[INT33FE_NODE_ROLE_SWITCH];
+ args[1].fwnode = NULL;
+
+ ref = fwnode_create_software_node_reference(con, "usb-role-switch",
+ args);
+ if (IS_ERR(ref)) {
+ cht_int33fe_remove_references(data);
+ return PTR_ERR(ref);
+ }
+ data->ref[INT33FE_REF_ROLE_SWITCH] = ref;
+
+ /* DisplayPort */
+ args[0].fwnode = data->node[INT33FE_NODE_DISPLAYPORT];
+ args[1].fwnode = NULL;
+
+ ref = fwnode_create_software_node_reference(con, "displayport", args);
+ if (IS_ERR(ref)) {
+ cht_int33fe_remove_references(data);
+ return PTR_ERR(ref);
+ }
+ data->ref[INT33FE_REF_DISPLAYPORT] = ref;
+
+ return 0;
+}
+
static int cht_int33fe_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -348,22 +414,14 @@ static int cht_int33fe_probe(struct platform_device *pdev)
if (ret)
return ret;
- /* Work around BIOS bug, see comment on cht_int33fe_check_for_max17047 */
- ret = cht_int33fe_register_max17047(dev, data);
+ ret = cht_int33fe_add_references(data);
if (ret)
goto out_remove_nodes;
- data->connections[0].endpoint[0] = "port0";
- data->connections[0].endpoint[1] = "i2c-pi3usb30532-switch";
- data->connections[0].id = "orientation-switch";
- data->connections[1].endpoint[0] = "port0";
- data->connections[1].endpoint[1] = "i2c-pi3usb30532-mux";
- data->connections[1].id = "mode-switch";
- data->connections[2].endpoint[0] = "i2c-fusb302";
- data->connections[2].endpoint[1] = "intel_xhci_usb_sw-role-switch";
- data->connections[2].id = "usb-role-switch";
-
- device_connections_add(data->connections);
+ /* Work around BIOS bug, see comment on cht_int33fe_check_for_max17047 */
+ ret = cht_int33fe_register_max17047(dev, data);
+ if (ret)
+ goto out_remove_references;
memset(&board_info, 0, sizeof(board_info));
strlcpy(board_info.type, "typec_fusb302", I2C_NAME_SIZE);
@@ -398,7 +456,8 @@ static int cht_int33fe_probe(struct platform_device *pdev)
out_unregister_max17047:
i2c_unregister_device(data->max17047);
- device_connections_remove(data->connections);
+out_remove_references:
+ cht_int33fe_remove_references(data);
out_remove_nodes:
cht_int33fe_remove_nodes(data);
@@ -414,7 +473,7 @@ static int cht_int33fe_remove(struct platform_device *pdev)
i2c_unregister_device(data->fusb302);
i2c_unregister_device(data->max17047);
- device_connections_remove(data->connections);
+ cht_int33fe_remove_references(data);
cht_int33fe_remove_nodes(data);
return 0;