MLK-14314-14 dma: pxp-v3: derive the shortest path table for 2D nodes

Based on the previously caculated adjacent list and mux
config info, the shortest path table can be derived by
distance calculation between two different 2D nodes.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>
(cherry picked from commit c8adf0f7089d5c5e286d7ae74c138a84bed5e280)

diff --git a/drivers/dma/pxp/pxp_dma_v3.c b/drivers/dma/pxp/pxp_dma_v3.c
index cd53fea..556ec60 100644 (file)
--- a/drivers/dma/pxp/pxp_dma_v3.c
+++ b/drivers/dma/pxp/pxp_dma_v3.c
@@ -179,6 +179,9 @@ struct pxps {
 #define PXP_2D_NODE_TYPE_ALU   2
 #define PXP_2D_NODE_TYPE_OUTPUT        3
 
+#define DISTANCE_INFINITY      0xffff
+#define NO_PATH_NODE           0xffffffff
+
 /* 4 to 1 mux */
 struct mux {
        uint32_t id;
@@ -200,7 +203,15 @@ struct vetex_node {
        struct edge_node *first;
 };
 
+struct path_node {
+       struct list_head node;
+       uint32_t id;
+       uint32_t distance;
+       uint32_t prev_node;
+};
+
 static struct vetex_node adj_list[PXP_2D_NODE_NUM];
+static struct path_node path_table[PXP_2D_NODE_NUM][PXP_2D_NODE_NUM];
 
 static bool adj_array[PXP_2D_NODE_NUM][PXP_2D_NODE_NUM] = {
       /* 0  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 */
@@ -5552,6 +5563,62 @@ static int pxp_create_initial_graph(struct platform_device *pdev)
        return 0;
 }
 
+/* Calculate the shortest paths start via
+ * 'from' node to other nodes
+ */
+static void pxp_find_shortest_path(unsigned int from)
+{
+       int i;
+       struct edge_node *enode;
+       struct path_node *pnode, *adjnode;
+       struct list_head queue;
+
+       INIT_LIST_HEAD(&queue);
+       list_add_tail(&path_table[from][from].node, &queue);
+
+       while(!list_empty(&queue)) {
+               pnode = list_entry(queue.next, struct path_node, node);
+               enode = adj_list[pnode->id].first;
+               while (enode) {
+                       adjnode = &path_table[from][enode->adjvex];
+
+                       if (adjnode->distance == DISTANCE_INFINITY) {
+                               adjnode->distance  = pnode->distance + 1;
+                               adjnode->prev_node = pnode->id;
+                               list_add_tail(&adjnode->node, &queue);
+                       }
+
+                       enode = enode->next;
+               }
+               list_del_init(&pnode->node);
+       }
+
+       for (i = 0; i < PXP_2D_NODE_NUM; i++)
+               printk(KERN_DEBUG "From %u: to %d (id = %d, distance = 0x%x, prev_node = %d\n",
+                       from, i, path_table[from][i].id, path_table[from][i].distance,
+                       path_table[from][i].prev_node);
+}
+
+static int pxp_gen_shortest_paths(struct platform_device *pdev)
+{
+       int i, j;
+
+       for (i = 0; i < PXP_2D_NODE_NUM; i++) {
+               for (j = 0; j < PXP_2D_NODE_NUM; j++) {
+                       path_table[i][j].id = j;
+                       path_table[i][j].distance = DISTANCE_INFINITY;
+                       path_table[i][j].prev_node = NO_PATH_NODE;
+                       INIT_LIST_HEAD(&path_table[i][j].node);
+               }
+
+               path_table[i][i].distance = 0;
+
+               pxp_find_shortest_path(i);
+       }
+
+       return 0;
+}
+
 #ifdef CONFIG_MXC_FPGA_M4_TEST
 static void pxp_config_m4(struct platform_device *pdev)
 {
@@ -5679,6 +5746,8 @@ static int pxp_probe(struct platform_device *pdev)
                goto exit;
        }
 
+       pxp_gen_shortest_paths(pdev);
+
 #ifdef CONFIG_MXC_FPGA_M4_TEST
        pxp_config_m4(pdev);
 #endif