Now memory controller is a memory interconnection provider. This allows us
to use interconnect API in order to change memory configuration.

Signed-off-by: Dmitry Osipenko <dig...@gmail.com>
---
 drivers/memory/tegra/Kconfig |   1 +
 drivers/memory/tegra/mc.c    | 118 +++++++++++++++++++++++++++++++++++
 drivers/memory/tegra/mc.h    |   8 +++
 include/soc/tegra/mc.h       |   3 +
 4 files changed, 130 insertions(+)

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index 5bf75b316a2f..7055fdef2c32 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -3,6 +3,7 @@ config TEGRA_MC
        bool "NVIDIA Tegra Memory Controller support"
        default y
        depends on ARCH_TEGRA
+       select INTERCONNECT
        help
          This driver supports the Memory Controller (MC) hardware found on
          NVIDIA Tegra SoCs.
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 772aa021b5f6..46759ddaa3c9 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -594,6 +594,122 @@ static __maybe_unused irqreturn_t tegra20_mc_irq(int irq, 
void *data)
        return IRQ_HANDLED;
 }
 
+static int tegra_mc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+       /*
+        * The plan is to populate this function with a latency allowness
+        * programming sometime later, for now this a dummy callback.
+        */
+       return 0;
+}
+
+static int tegra_mc_icc_aggregate(struct icc_node *node,
+                                 u32 tag, u32 avg_bw, u32 peak_bw,
+                                 u32 *agg_avg, u32 *agg_peak)
+{
+       *agg_avg = min((u64)avg_bw + (*agg_avg), (u64)U32_MAX);
+       *agg_peak = max(*agg_peak, peak_bw);
+
+       return 0;
+}
+
+/*
+ * Memory Controller (MC) has few Memory Clients that are issuing memory
+ * bandwidth allocation requests to the MC interconnect provider. The MC
+ * provider aggregates the requests and then sends the aggregated request
+ * up to the External Memory Controller (EMC) interconnect provider which
+ * re-configures hardware interface to External Memory (EMEM) in accordance
+ * to the required bandwidth. Each MC interconnect node represents an
+ * individual Memory Client.
+ *
+ * Memory interconnect topology:
+ *
+ *               +----+
+ * +--------+    |    |
+ * | TEXSRD +--->+    |
+ * +--------+    |    |
+ *               |    |    +-----+    +------+
+ *    ...        | MC +--->+ EMC +--->+ EMEM |
+ *               |    |    +-----+    +------+
+ * +--------+    |    |
+ * | DISP.. +--->+    |
+ * +--------+    |    |
+ *               +----+
+ */
+static int tegra_mc_interconnect_setup(struct tegra_mc *mc)
+{
+       struct icc_onecell_data *data;
+       struct icc_node *node;
+       unsigned int num_nodes;
+       unsigned int i;
+       int err;
+
+       /* older device-trees don't have interconnect properties */
+       if (!of_find_property(mc->dev->of_node, "#interconnect-cells", NULL))
+               return 0;
+
+       num_nodes = mc->soc->num_clients;
+
+       data = devm_kzalloc(mc->dev, struct_size(data, nodes, num_nodes),
+                           GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       mc->provider.dev = mc->dev;
+       mc->provider.set = tegra_mc_icc_set;
+       mc->provider.data = data;
+       mc->provider.xlate = of_icc_xlate_onecell;
+       mc->provider.aggregate = tegra_mc_icc_aggregate;
+
+       err = icc_provider_add(&mc->provider);
+       if (err)
+               goto err_msg;
+
+       /* create Memory Controller node */
+       node = icc_node_create(TEGRA_ICC_MC);
+       err = PTR_ERR_OR_ZERO(node);
+       if (err)
+               goto del_provider;
+
+       node->name = "Memory Controller";
+       icc_node_add(node, &mc->provider);
+
+       /* link Memory Controller to External Memory Controller */
+       err = icc_link_create(node, TEGRA_ICC_EMC);
+       if (err)
+               goto remove_nodes;
+
+       for (i = 0; i < num_nodes; i++) {
+               /* create MC client node */
+               node = icc_node_create(mc->soc->clients[i].id);
+               err = PTR_ERR_OR_ZERO(node);
+               if (err)
+                       goto remove_nodes;
+
+               node->name = mc->soc->clients[i].name;
+               icc_node_add(node, &mc->provider);
+
+               /* link Memory Client to Memory Controller */
+               err = icc_link_create(node, TEGRA_ICC_MC);
+               if (err)
+                       goto remove_nodes;
+
+               data->nodes[i] = node;
+       }
+       data->num_nodes = num_nodes;
+
+       return 0;
+
+remove_nodes:
+       icc_nodes_remove(&mc->provider);
+del_provider:
+       icc_provider_del(&mc->provider);
+err_msg:
+       dev_err(mc->dev, "failed to initialize ICC: %d\n", err);
+
+       return err;
+}
+
 static int tegra_mc_probe(struct platform_device *pdev)
 {
        struct resource *res;
@@ -702,6 +818,8 @@ static int tegra_mc_probe(struct platform_device *pdev)
                }
        }
 
+       tegra_mc_interconnect_setup(mc);
+
        return 0;
 }
 
diff --git a/drivers/memory/tegra/mc.h b/drivers/memory/tegra/mc.h
index afa3ba45c9e6..abeb6a2cc36a 100644
--- a/drivers/memory/tegra/mc.h
+++ b/drivers/memory/tegra/mc.h
@@ -115,4 +115,12 @@ extern const struct tegra_mc_soc tegra132_mc_soc;
 extern const struct tegra_mc_soc tegra210_mc_soc;
 #endif
 
+/*
+ * These IDs are for internal use of Tegra's ICC, the values are chosen
+ * such that they don't conflict with the device-tree ICC node IDs.
+ */
+#define TEGRA_ICC_EMC          1000
+#define TEGRA_ICC_EMEM         2000
+#define TEGRA_ICC_MC           3000
+
 #endif /* MEMORY_TEGRA_MC_H */
diff --git a/include/soc/tegra/mc.h b/include/soc/tegra/mc.h
index 1238e35653d1..71de023f9f47 100644
--- a/include/soc/tegra/mc.h
+++ b/include/soc/tegra/mc.h
@@ -7,6 +7,7 @@
 #define __SOC_TEGRA_MC_H__
 
 #include <linux/err.h>
+#include <linux/interconnect-provider.h>
 #include <linux/reset-controller.h>
 #include <linux/types.h>
 
@@ -178,6 +179,8 @@ struct tegra_mc {
 
        struct reset_controller_dev reset;
 
+       struct icc_provider provider;
+
        spinlock_t lock;
 };
 
-- 
2.27.0

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