From: Prashant Malani <pmalani@chromium.org>
Date: Wed, 11 Jan 2023 02:05:41 +0000 (+0000)
Subject: usb: typec: altmodes/displayport: Add pin assignment helper
X-Git-Tag: baikal/aarch64/sdk5.9~151
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=cfd5eab9df7821993d5ffb92b4bccb672e73367b;p=kernel.git

usb: typec: altmodes/displayport: Add pin assignment helper

commit 582836e3cfab4faafbdc93bbec96fce036a08ee1 upstream.

The code to extract a peripheral's currently supported Pin Assignments
is repeated in a couple of locations. Factor it out into a separate
function.

This will also make it easier to add fixes (we only need to update 1
location instead of 2).

Fixes: 29d676ffd363 ("usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles")
Cc: stable@vger.kernel.org
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230111020546.3384569-1-pmalani@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index 0b5cbf5ed1ca6..c43b0dbe9368a 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -407,6 +407,18 @@ static const char * const pin_assignments[] = {
 	[DP_PIN_ASSIGN_F] = "F",
 };
 
+/*
+ * Helper function to extract a peripheral's currently supported
+ * Pin Assignments from its DisplayPort alternate mode state.
+ */
+static u8 get_current_pin_assignments(struct dp_altmode *dp)
+{
+	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
+		return DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
+	else
+		return DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
+}
+
 static ssize_t
 pin_assignment_store(struct device *dev, struct device_attribute *attr,
 		     const char *buf, size_t size)
@@ -433,10 +445,7 @@ pin_assignment_store(struct device *dev, struct device_attribute *attr,
 		goto out_unlock;
 	}
 
-	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
-		assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
-	else
-		assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
+	assignments = get_current_pin_assignments(dp);
 
 	if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
 		ret = -EINVAL;
@@ -473,10 +482,7 @@ static ssize_t pin_assignment_show(struct device *dev,
 
 	cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
 
-	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
-		assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
-	else
-		assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
+	assignments = get_current_pin_assignments(dp);
 
 	for (i = 0; assignments; assignments >>= 1, i++) {
 		if (assignments & 1) {