memory: tegra: Add interconnect support for DRAM scaling in Tegra234

Add Interconnect framework support to dynamically set the DRAM
bandwidth from different clients. Both the MC and EMC drivers are
added as ICC providers. The path for any request is:
 MC-Client[1-n] -> MC -> EMC -> EMEM/DRAM

MC client's request for bandwidth will go to the MC driver which
passes the client request info like BPMP Client ID, Client type
and the Bandwidth to the BPMP-FW. The final DRAM freq to achieve
the requested bandwidth is set by the BPMP-FW based on the passed
parameters.

Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

3 files changed, 275 insertions, 1 deletions

diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index 9082b6c3763d..983455b1f98d 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -15,6 +15,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/sort.h>
+#include <linux/tegra-icc.h>
 
 #include <soc/tegra/fuse.h>
 
@@ -792,6 +793,8 @@ static int tegra_mc_interconnect_setup(struct tegra_mc *mc)
 	mc->provider.data = &mc->provider;
 	mc->provider.set = mc->soc->icc_ops->set;
 	mc->provider.aggregate = mc->soc->icc_ops->aggregate;
+	mc->provider.get_bw = mc->soc->icc_ops->get_bw;
+	mc->provider.xlate = mc->soc->icc_ops->xlate;
 	mc->provider.xlate_extended = mc->soc->icc_ops->xlate_extended;
 
 	icc_provider_init(&mc->provider);
@@ -824,6 +827,8 @@ static int tegra_mc_interconnect_setup(struct tegra_mc *mc)
 		err = icc_link_create(node, TEGRA_ICC_MC);
 		if (err)
 			goto remove_nodes;
+
+		node->data = (struct tegra_mc_client *)&(mc->soc->clients[i]);
 	}
 
 	err = icc_provider_register(&mc->provider);
diff --git a/drivers/memory/tegra/tegra186-emc.c b/drivers/memory/tegra/tegra186-emc.c
index e935ad4e95b6..6ad8a4023dd7 100644
--- a/drivers/memory/tegra/tegra186-emc.c
+++ b/drivers/memory/tegra/tegra186-emc.c
@@ -7,9 +7,11 @@
 #include <linux/debugfs.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 
 #include <soc/tegra/bpmp.h>
+#include "mc.h"
 
 struct tegra186_emc_dvfs {
 	unsigned long latency;
@@ -29,8 +31,15 @@ struct tegra186_emc {
 		unsigned long min_rate;
 		unsigned long max_rate;
 	} debugfs;
+
+	struct icc_provider provider;
 };
 
+static inline struct tegra186_emc *to_tegra186_emc(struct icc_provider *provider)
+{
+	return container_of(provider, struct tegra186_emc, provider);
+}
+
 /*
  * debugfs interface
  *
@@ -146,8 +155,102 @@ DEFINE_DEBUGFS_ATTRIBUTE(tegra186_emc_debug_max_rate_fops,
 			  tegra186_emc_debug_max_rate_get,
 			  tegra186_emc_debug_max_rate_set, "%llu\n");
 
+/*
+ * tegra_emc_icc_set_bw() - Set BW api for EMC provider
+ * @src: ICC node for External Memory Controller (EMC)
+ * @dst: ICC node for External Memory (DRAM)
+ *
+ * Do nothing here as info to BPMP-FW is now passed in the BW set function
+ * of the MC driver. BPMP-FW sets the final Freq based on the passed values.
+ */
+static int tegra_emc_icc_set_bw(struct icc_node *src, struct icc_node *dst)
+{
+	return 0;
+}
+
+static struct icc_node *
+tegra_emc_of_icc_xlate(struct of_phandle_args *spec, void *data)
+{
+	struct icc_provider *provider = data;
+	struct icc_node *node;
+
+	/* External Memory is the only possible ICC route */
+	list_for_each_entry(node, &provider->nodes, node_list) {
+		if (node->id != TEGRA_ICC_EMEM)
+			continue;
+
+		return node;
+	}
+
+	return ERR_PTR(-EPROBE_DEFER);
+}
+
+static int tegra_emc_icc_get_init_bw(struct icc_node *node, u32 *avg, u32 *peak)
+{
+	*avg = 0;
+	*peak = 0;
+
+	return 0;
+}
+
+static int tegra_emc_interconnect_init(struct tegra186_emc *emc)
+{
+	struct tegra_mc *mc = dev_get_drvdata(emc->dev->parent);
+	const struct tegra_mc_soc *soc = mc->soc;
+	struct icc_node *node;
+	int err;
+
+	emc->provider.dev = emc->dev;
+	emc->provider.set = tegra_emc_icc_set_bw;
+	emc->provider.data = &emc->provider;
+	emc->provider.aggregate = soc->icc_ops->aggregate;
+	emc->provider.xlate = tegra_emc_of_icc_xlate;
+	emc->provider.get_bw = tegra_emc_icc_get_init_bw;
+
+	icc_provider_init(&emc->provider);
+
+	/* create External Memory Controller node */
+	node = icc_node_create(TEGRA_ICC_EMC);
+	if (IS_ERR(node)) {
+		err = PTR_ERR(node);
+		goto err_msg;
+	}
+
+	node->name = "External Memory Controller";
+	icc_node_add(node, &emc->provider);
+
+	/* link External Memory Controller to External Memory (DRAM) */
+	err = icc_link_create(node, TEGRA_ICC_EMEM);
+	if (err)
+		goto remove_nodes;
+
+	/* create External Memory node */
+	node = icc_node_create(TEGRA_ICC_EMEM);
+	if (IS_ERR(node)) {
+		err = PTR_ERR(node);
+		goto remove_nodes;
+	}
+
+	node->name = "External Memory (DRAM)";
+	icc_node_add(node, &emc->provider);
+
+	err = icc_provider_register(&emc->provider);
+	if (err)
+		goto remove_nodes;
+
+	return 0;
+
+remove_nodes:
+	icc_nodes_remove(&emc->provider);
+err_msg:
+	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
+
+	return err;
+}
+
 static int tegra186_emc_probe(struct platform_device *pdev)
 {
+	struct tegra_mc *mc = dev_get_drvdata(pdev->dev.parent);
 	struct mrq_emc_dvfs_latency_response response;
 	struct tegra_bpmp_message msg;
 	struct tegra186_emc *emc;
@@ -236,6 +339,32 @@ static int tegra186_emc_probe(struct platform_device *pdev)
 	debugfs_create_file("max_rate", S_IRUGO | S_IWUSR, emc->debugfs.root,
 			    emc, &tegra186_emc_debug_max_rate_fops);
 
+	if (mc && mc->soc->icc_ops) {
+		if (tegra_bpmp_mrq_is_supported(emc->bpmp, MRQ_BWMGR_INT)) {
+			mc->bwmgr_mrq_supported = true;
+
+			/*
+			 * MC driver probe can't get BPMP reference as it gets probed
+			 * earlier than BPMP. So, save the BPMP ref got from the EMC
+			 * DT node in the mc->bpmp and use it in MC's icc_set hook.
+			 */
+			mc->bpmp = emc->bpmp;
+			barrier();
+		}
+
+		/*
+		 * Initialize the ICC even if BPMP-FW doesn't support 'MRQ_BWMGR_INT'.
+		 * Use the flag 'mc->bwmgr_mrq_supported' within MC driver and return
+		 * EINVAL instead of passing the request to BPMP-FW later when the BW
+		 * request is made by client with 'icc_set_bw()' call.
+		 */
+		err = tegra_emc_interconnect_init(emc);
+		if (err) {
+			mc->bpmp = NULL;
+			goto put_bpmp;
+		}
+	}
+
 	return 0;
 
 put_bpmp:
@@ -245,9 +374,12 @@ put_bpmp:
 
 static int tegra186_emc_remove(struct platform_device *pdev)
 {
+	struct tegra_mc *mc = dev_get_drvdata(pdev->dev.parent);
 	struct tegra186_emc *emc = platform_get_drvdata(pdev);
 
 	debugfs_remove_recursive(emc->debugfs.root);
+
+	mc->bpmp = NULL;
 	tegra_bpmp_put(emc->bpmp);
 
 	return 0;
@@ -272,6 +404,7 @@ static struct platform_driver tegra186_emc_driver = {
 		.name = "tegra186-emc",
 		.of_match_table = tegra186_emc_of_match,
 		.suppress_bind_attrs = true,
+		.sync_state = icc_sync_state,
 	},
 	.probe = tegra186_emc_probe,
 	.remove = tegra186_emc_remove,
diff --git a/drivers/memory/tegra/tegra234.c b/drivers/memory/tegra/tegra234.c
index 02dcc5748bba..56d911926d54 100644
--- a/drivers/memory/tegra/tegra234.c
+++ b/drivers/memory/tegra/tegra234.c
@@ -1,18 +1,23 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (C) 2021-2022, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (C) 2022-2023, NVIDIA CORPORATION.  All rights reserved.
  */
 
 #include <soc/tegra/mc.h>
 
 #include <dt-bindings/memory/tegra234-mc.h>
+#include <linux/interconnect.h>
+#include <linux/tegra-icc.h>
 
+#include <soc/tegra/bpmp.h>
 #include "mc.h"
 
 static const struct tegra_mc_client tegra234_mc_clients[] = {
 	{
 		.id = TEGRA234_MEMORY_CLIENT_MGBEARD,
 		.name = "mgbeard",
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_MGBE,
 		.regs = {
 			.sid = {
@@ -23,6 +28,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_MGBEBRD,
 		.name = "mgbebrd",
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_MGBE_VF1,
 		.regs = {
 			.sid = {
@@ -33,6 +40,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_MGBECRD,
 		.name = "mgbecrd",
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_MGBE_VF2,
 		.regs = {
 			.sid = {
@@ -43,6 +52,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_MGBEDRD,
 		.name = "mgbedrd",
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_MGBE_VF3,
 		.regs = {
 			.sid = {
@@ -52,6 +63,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 		},
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_MGBEAWR,
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.name = "mgbeawr",
 		.sid = TEGRA234_SID_MGBE,
 		.regs = {
@@ -63,6 +76,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_MGBEBWR,
 		.name = "mgbebwr",
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_MGBE_VF1,
 		.regs = {
 			.sid = {
@@ -73,6 +88,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_MGBECWR,
 		.name = "mgbecwr",
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_MGBE_VF2,
 		.regs = {
 			.sid = {
@@ -83,6 +100,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_SDMMCRAB,
 		.name = "sdmmcrab",
+		.bpmp_id = TEGRA_ICC_BPMP_SDMMC_4,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_SDMMC4,
 		.regs = {
 			.sid = {
@@ -93,6 +112,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_MGBEDWR,
 		.name = "mgbedwr",
+		.bpmp_id = TEGRA_ICC_BPMP_EQOS,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_MGBE_VF3,
 		.regs = {
 			.sid = {
@@ -103,6 +124,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_SDMMCWAB,
 		.name = "sdmmcwab",
+		.bpmp_id = TEGRA_ICC_BPMP_SDMMC_4,
+		.type = TEGRA_ICC_NISO,
 		.sid = TEGRA234_SID_SDMMC4,
 		.regs = {
 			.sid = {
@@ -153,6 +176,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_APEDMAR,
 		.name = "apedmar",
+		.bpmp_id = TEGRA_ICC_BPMP_APEDMA,
+		.type = TEGRA_ICC_ISO_AUDIO,
 		.sid = TEGRA234_SID_APE,
 		.regs = {
 			.sid = {
@@ -163,6 +188,8 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	}, {
 		.id = TEGRA234_MEMORY_CLIENT_APEDMAW,
 		.name = "apedmaw",
+		.bpmp_id = TEGRA_ICC_BPMP_APEDMA,
+		.type = TEGRA_ICC_ISO_AUDIO,
 		.sid = TEGRA234_SID_APE,
 		.regs = {
 			.sid = {
@@ -333,6 +360,114 @@ static const struct tegra_mc_client tegra234_mc_clients[] = {
 	},
 };
 
+/*
+ * tegra234_mc_icc_set() - Pass MC client info to the BPMP-FW
+ * @src: ICC node for Memory Controller's (MC) Client
+ * @dst: ICC node for Memory Controller (MC)
+ *
+ * Passing the current request info from the MC to the BPMP-FW where
+ * LA and PTSA registers are accessed and the final EMC freq is set
+ * based on client_id, type, latency and bandwidth.
+ * icc_set_bw() makes set_bw calls for both MC and EMC providers in
+ * sequence. Both the calls are protected by 'mutex_lock(&icc_lock)'.
+ * So, the data passed won't be updated by concurrent set calls from
+ * other clients.
+ */
+static int tegra234_mc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+	struct tegra_mc *mc = icc_provider_to_tegra_mc(dst->provider);
+	struct mrq_bwmgr_int_request bwmgr_req = { 0 };
+	struct mrq_bwmgr_int_response bwmgr_resp = { 0 };
+	const struct tegra_mc_client *pclient = src->data;
+	struct tegra_bpmp_message msg;
+	int ret;
+
+	/*
+	 * Same Src and Dst node will happen during boot from icc_node_add().
+	 * This can be used to pre-initialize and set bandwidth for all clients
+	 * before their drivers are loaded. We are skipping this case as for us,
+	 * the pre-initialization already happened in Bootloader(MB2) and BPMP-FW.
+	 */
+	if (src->id == dst->id)
+		return 0;
+
+	if (!mc->bwmgr_mrq_supported)
+		return -EINVAL;
+
+	if (!mc->bpmp) {
+		dev_err(mc->dev, "BPMP reference NULL\n");
+		return -ENOENT;
+	}
+
+	if (pclient->type == TEGRA_ICC_NISO)
+		bwmgr_req.bwmgr_calc_set_req.niso_bw = src->avg_bw;
+	else
+		bwmgr_req.bwmgr_calc_set_req.iso_bw = src->avg_bw;
+
+	bwmgr_req.bwmgr_calc_set_req.client_id = pclient->bpmp_id;
+
+	bwmgr_req.cmd = CMD_BWMGR_INT_CALC_AND_SET;
+	bwmgr_req.bwmgr_calc_set_req.mc_floor = src->peak_bw;
+	bwmgr_req.bwmgr_calc_set_req.floor_unit = BWMGR_INT_UNIT_KBPS;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.mrq = MRQ_BWMGR_INT;
+	msg.tx.data = &bwmgr_req;
+	msg.tx.size = sizeof(bwmgr_req);
+	msg.rx.data = &bwmgr_resp;
+	msg.rx.size = sizeof(bwmgr_resp);
+
+	ret = tegra_bpmp_transfer(mc->bpmp, &msg);
+	if (ret < 0) {
+		dev_err(mc->dev, "BPMP transfer failed: %d\n", ret);
+		goto error;
+	}
+	if (msg.rx.ret < 0) {
+		pr_err("failed to set bandwidth for %u: %d\n",
+		       bwmgr_req.bwmgr_calc_set_req.client_id, msg.rx.ret);
+		ret = -EINVAL;
+	}
+
+error:
+	return ret;
+}
+
+static struct icc_node*
+tegra234_mc_of_icc_xlate(struct of_phandle_args *spec, void *data)
+{
+	struct tegra_mc *mc = icc_provider_to_tegra_mc(data);
+	unsigned int cl_id = spec->args[0];
+	struct icc_node *node;
+
+	list_for_each_entry(node, &mc->provider.nodes, node_list) {
+		if (node->id != cl_id)
+			continue;
+
+		return node;
+	}
+
+	/*
+	 * If a client driver calls devm_of_icc_get() before the MC driver
+	 * is probed, then return EPROBE_DEFER to the client driver.
+	 */
+	return ERR_PTR(-EPROBE_DEFER);
+}
+
+static int tegra234_mc_icc_get_init_bw(struct icc_node *node, u32 *avg, u32 *peak)
+{
+	*avg = 0;
+	*peak = 0;
+
+	return 0;
+}
+
+static const struct tegra_mc_icc_ops tegra234_mc_icc_ops = {
+	.xlate = tegra234_mc_of_icc_xlate,
+	.aggregate = icc_std_aggregate,
+	.get_bw = tegra234_mc_icc_get_init_bw,
+	.set = tegra234_mc_icc_set,
+};
+
 const struct tegra_mc_soc tegra234_mc_soc = {
 	.num_clients = ARRAY_SIZE(tegra234_mc_clients),
 	.clients = tegra234_mc_clients,
@@ -345,6 +480,7 @@ const struct tegra_mc_soc tegra234_mc_soc = {
 		   MC_INT_SECURITY_VIOLATION | MC_INT_DECERR_EMEM,
 	.has_addr_hi_reg = true,
 	.ops = &tegra186_mc_ops,
+	.icc_ops = &tegra234_mc_icc_ops,
 	.ch_intmask = 0x0000ff00,
 	.global_intstatus_channel_shift = 8,
 	/*