[PATCH net-next v2 07/14] dpll: dpllsim: Add support to get/set priority on input pins

@@ -36,6 +36,9 @@ Pin directory ``/sys/kernel/config/dpllsim/<dev>/pins/<pin>/``:
                (default 0, which is rejected)
 ``direction``  ``input`` or ``output`` (default ``input``), a ``mux`` pin
                must be an input
+``prio``       Priority 0-255 used for automatic reference selection,
+               input pins only, output pins must keep the default
+               (default 128)
 =============  ===============================================================
 
 The pin directory name becomes the board label of the pin. Pins are

@@ -53,8 +56,10 @@ output, then make it live::
     mkdir pins/gnss0
     echo gnss > pins/gnss0/type
     echo 1 > pins/gnss0/frequency
+    echo 0 > pins/gnss0/prio
     mkdir pins/ext0
     echo 10000000 > pins/ext0/frequency
+    echo 1 > pins/ext0/prio
     mkdir pins/out0
     echo 10000000 > pins/out0/frequency
     echo output > pins/out0/direction

@@ -132,10 +132,40 @@ static ssize_t dpllsim_pin_frequency_store(struct config_item *item,
 }
 CONFIGFS_ATTR(dpllsim_pin_, frequency);
 
+static ssize_t dpllsim_pin_prio_show(struct config_item *item, char *page)
+{
+	struct dpllsim_pin *pin = to_dpllsim_pin(item);
+
+	guard(mutex)(&pin->dev->lock);
+	return sysfs_emit(page, "%u\n", pin->prio);
+}
+
+static ssize_t dpllsim_pin_prio_store(struct config_item *item,
+				      const char *page, size_t count)
+{
+	struct dpllsim_pin *pin = to_dpllsim_pin(item);
+	u32 val;
+	int err;
+
+	err = kstrtou32(page, 10, &val);
+	if (err)
+		return err;
+	if (val > DPLLSIM_PIN_PRIO_MAX)
+		return -EINVAL;
+
+	guard(mutex)(&pin->dev->lock);
+	if (dpllsim_dev_frozen(pin->dev))
+		return -EBUSY;
+	pin->prio = val;
+	return count;
+}
+CONFIGFS_ATTR(dpllsim_pin_, prio);
+
 static struct configfs_attribute *dpllsim_pin_attrs[] = {
 	&dpllsim_pin_attr_type,
 	&dpllsim_pin_attr_direction,
 	&dpllsim_pin_attr_frequency,
+	&dpllsim_pin_attr_prio,
 	NULL,
 };
 

@@ -178,6 +208,7 @@ static struct config_item *dpllsim_pins_make_item(struct config_group *group,
 	pin->dev = sim;
 	pin->type = DPLL_PIN_TYPE_EXT;
 	pin->direction = DPLL_PIN_DIRECTION_INPUT;
+	pin->prio = DPLLSIM_DEFAULT_PIN_PRIO;
 	list_add_tail(&pin->list, &sim->pin_list);
 
 	return &pin->item;

@@ -116,11 +116,43 @@ static int dpllsim_pin_state_set(const struct dpll_pin *pin, void *pin_priv,
 	return 0;
 }
 
+static int dpllsim_pin_prio_get(const struct dpll_pin *pin, void *pin_priv,
+				const struct dpll_device *dpll,
+				void *dpll_priv, u32 *prio,
+				struct netlink_ext_ack *extack)
+{
+	struct dpllsim_pin *sim_pin = pin_priv;
+
+	guard(mutex)(&sim_pin->dev->lock);
+	*prio = sim_pin->prio;
+	return 0;
+}
+
+static int dpllsim_pin_prio_set(const struct dpll_pin *pin, void *pin_priv,
+				const struct dpll_device *dpll,
+				void *dpll_priv, u32 prio,
+				struct netlink_ext_ack *extack)
+{
+	struct dpllsim_pin *sim_pin = pin_priv;
+
+	if (prio > DPLLSIM_PIN_PRIO_MAX) {
+		NL_SET_ERR_MSG_FMT(extack, "Pin priority must be in range 0-%u",
+				   DPLLSIM_PIN_PRIO_MAX);
+		return -EINVAL;
+	}
+
+	guard(mutex)(&sim_pin->dev->lock);
+	sim_pin->prio = prio;
+	return 0;
+}
+
 static const struct dpll_pin_ops dpllsim_input_pin_ops = {
 	.frequency_get = dpllsim_pin_frequency_get,
 	.direction_get = dpllsim_pin_direction_get,
 	.state_on_dpll_get = dpllsim_pin_state_get,
 	.state_on_dpll_set = dpllsim_pin_state_set,
+	.prio_get = dpllsim_pin_prio_get,
+	.prio_set = dpllsim_pin_prio_set,
 };
 
 static const struct dpll_pin_ops dpllsim_output_pin_ops = {

@@ -165,7 +197,8 @@ static void dpllsim_pin_props(struct dpllsim_pin *pin,
 
 	/* Capabilities follow the ops the pin is served by */
 	if (dpllsim_pin_select_ops(pin) == &dpllsim_input_pin_ops)
-		prop->capabilities = DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE;
+		prop->capabilities = DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE |
+				     DPLL_PIN_CAPABILITIES_PRIORITY_CAN_CHANGE;
 	else
 		prop->capabilities = 0;
 }

@@ -191,6 +224,13 @@ static bool dpllsim_pin_direction_valid(const struct dpllsim_pin *pin)
 	       pin->direction == DPLL_PIN_DIRECTION_INPUT;
 }
 
+/* Priority is meaningful for input pins only */
+static bool dpllsim_pin_prio_valid(const struct dpllsim_pin *pin)
+{
+	return pin->direction == DPLL_PIN_DIRECTION_INPUT ||
+	       pin->prio == DPLLSIM_DEFAULT_PIN_PRIO;
+}
+
 static void dpllsim_pin_reset(struct dpllsim_pin *pin)
 {
 	pin->ops = dpllsim_pin_select_ops(pin);

@@ -205,7 +245,8 @@ static int dpllsim_order_pins(struct dpllsim_dev *sim)
 
 	list_for_each_entry(pin, &sim->pin_list, list) {
 		if (!dpllsim_pin_frequency_valid(pin) ||
-		    !dpllsim_pin_direction_valid(pin))
+		    !dpllsim_pin_direction_valid(pin) ||
+		    !dpllsim_pin_prio_valid(pin))
 			return -EINVAL;
 		count++;
 	}

@@ -12,6 +12,9 @@
 #include <linux/list.h>
 #include <linux/mutex.h>
 
+#define DPLLSIM_DEFAULT_PIN_PRIO		128
+#define DPLLSIM_PIN_PRIO_MAX			255
+
 #define DPLLSIM_MAX_PINS			128
 
 struct dpllsim_dev;

@@ -21,10 +24,15 @@ struct dpllsim_pin {
 	struct list_head list;
 	struct dpllsim_dev *dev;
 
-	/* Configuration, writable only until dpllsim_dev_frozen() */
+	/*
+	 * Configuration, set through configfs only until
+	 * dpllsim_dev_frozen(). The netlink prio setter changes prio at
+	 * runtime under dev->lock.
+	 */
 	enum dpll_pin_type type;
 	enum dpll_pin_direction direction;
 	u64 frequency;
+	u32 prio;
 
 	/* Resolved at live=1 */
 	int idx;