drivers/memory/tegra/tegra186-emc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2019 NVIDIA CORPORATION.  All rights reserved.
  */

 #include <linux/clk.h>
 #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;
 	unsigned long rate;
 };

 struct tegra186_emc {
 	struct tegra_bpmp *bpmp;
 	struct device *dev;
 	struct clk *clk;

 	struct tegra186_emc_dvfs *dvfs;
 	unsigned int num_dvfs;

 	struct {
 		struct dentry *root;
 		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
  *
  * The memory controller driver exposes some files in debugfs that can be used
  * to control the EMC frequency. The top-level directory can be found here:
  *
  *   /sys/kernel/debug/emc
  *
  * It contains the following files:
  *
  *   - available_rates: This file contains a list of valid, space-separated
  *     EMC frequencies.
  *
  *   - min_rate: Writing a value to this file sets the given frequency as the
  *       floor of the permitted range. If this is higher than the currently
  *       configured EMC frequency, this will cause the frequency to be
  *       increased so that it stays within the valid range.
  *
  *   - max_rate: Similarily to the min_rate file, writing a value to this file
  *       sets the given frequency as the ceiling of the permitted range. If
  *       the value is lower than the currently configured EMC frequency, this
  *       will cause the frequency to be decreased so that it stays within the
  *       valid range.
  */

 static bool tegra186_emc_validate_rate(struct tegra186_emc *emc,
 				       unsigned long rate)
 {
 	unsigned int i;

 	for (i = 0; i < emc->num_dvfs; i++)
 		if (rate == emc->dvfs[i].rate)
 			return true;

 	return false;
 }

 static int tegra186_emc_debug_available_rates_show(struct seq_file *s,
 						   void *data)
 {
 	struct tegra186_emc *emc = s->private;
 	const char *prefix = "";
 	unsigned int i;

 	for (i = 0; i < emc->num_dvfs; i++) {
 		seq_printf(s, "%s%lu", prefix, emc->dvfs[i].rate);
 		prefix = " ";
 	}

 	seq_puts(s, "\n");

 	return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(tegra186_emc_debug_available_rates);

 static int tegra186_emc_debug_min_rate_get(void *data, u64 *rate)
 {
 	struct tegra186_emc *emc = data;

 	*rate = emc->debugfs.min_rate;

 	return 0;
 }

 static int tegra186_emc_debug_min_rate_set(void *data, u64 rate)
 {
 	struct tegra186_emc *emc = data;
 	int err;

 	if (!tegra186_emc_validate_rate(emc, rate))
 		return -EINVAL;

 	err = clk_set_min_rate(emc->clk, rate);
 	if (err < 0)
 		return err;

 	emc->debugfs.min_rate = rate;

 	return 0;
 }

 DEFINE_DEBUGFS_ATTRIBUTE(tegra186_emc_debug_min_rate_fops,
 			  tegra186_emc_debug_min_rate_get,
 			  tegra186_emc_debug_min_rate_set, "%llu\n");

 static int tegra186_emc_debug_max_rate_get(void *data, u64 *rate)
 {
 	struct tegra186_emc *emc = data;

 	*rate = emc->debugfs.max_rate;

 	return 0;
 }

 static int tegra186_emc_debug_max_rate_set(void *data, u64 rate)
 {
 	struct tegra186_emc *emc = data;
 	int err;

 	if (!tegra186_emc_validate_rate(emc, rate))
 		return -EINVAL;

 	err = clk_set_max_rate(emc->clk, rate);
 	if (err < 0)
 		return err;

 	emc->debugfs.max_rate = rate;

 	return 0;
 }

 DEFINE_DEBUGFS_ATTRIBUTE(tegra186_emc_debug_max_rate_fops,
 			  tegra186_emc_debug_max_rate_get,
 			  tegra186_emc_debug_max_rate_set, "%llu\n");

 static int tegra186_emc_get_emc_dvfs_latency(struct tegra186_emc *emc)
 {
 	struct mrq_emc_dvfs_latency_response response;
 	struct tegra_bpmp_message msg;
 	unsigned int i;
 	int err;

 	memset(&msg, 0, sizeof(msg));
 	msg.mrq = MRQ_EMC_DVFS_LATENCY;
 	msg.tx.data = NULL;
 	msg.tx.size = 0;
 	msg.rx.data = &response;
 	msg.rx.size = sizeof(response);

 	err = tegra_bpmp_transfer(emc->bpmp, &msg);
 	if (err < 0) {
 		dev_err(emc->dev, "failed to EMC DVFS pairs: %d\n", err);
 		return err;
 	}
 	if (msg.rx.ret < 0) {
 		dev_err(emc->dev, "EMC DVFS MRQ failed: %d (BPMP error code)\n", msg.rx.ret);
 		return -EINVAL;
 	}

 	emc->debugfs.min_rate = ULONG_MAX;
 	emc->debugfs.max_rate = 0;

 	emc->num_dvfs = response.num_pairs;

 	emc->dvfs = devm_kmalloc_array(emc->dev, emc->num_dvfs, sizeof(*emc->dvfs), GFP_KERNEL);
 	if (!emc->dvfs)
 		return -ENOMEM;

 	dev_dbg(emc->dev, "%u DVFS pairs:\n", emc->num_dvfs);

 	for (i = 0; i < emc->num_dvfs; i++) {
 		emc->dvfs[i].rate = response.pairs[i].freq * 1000;
 		emc->dvfs[i].latency = response.pairs[i].latency;

 		if (emc->dvfs[i].rate < emc->debugfs.min_rate)
 			emc->debugfs.min_rate = emc->dvfs[i].rate;

 		if (emc->dvfs[i].rate > emc->debugfs.max_rate)
 			emc->debugfs.max_rate = emc->dvfs[i].rate;

 		dev_dbg(emc->dev, "  %2u: %lu Hz -> %lu us\n", i,
 			emc->dvfs[i].rate, emc->dvfs[i].latency);
 	}

 	err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate, emc->debugfs.max_rate);
 	if (err < 0) {
 		dev_err(emc->dev, "failed to set rate range [%lu-%lu] for %pC\n",
 			emc->debugfs.min_rate, emc->debugfs.max_rate, emc->clk);
 		return err;
 	}

 	emc->debugfs.root = debugfs_create_dir("emc", NULL);
 	debugfs_create_file("available_rates", 0444, emc->debugfs.root, emc,
 			    &tegra186_emc_debug_available_rates_fops);
 	debugfs_create_file("min_rate", 0644, emc->debugfs.root, emc,
 			    &tegra186_emc_debug_min_rate_fops);
 	debugfs_create_file("max_rate", 0644, emc->debugfs.root, emc,
 			    &tegra186_emc_debug_max_rate_fops);

 	return 0;
 }

 /*
  * 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(const 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 tegra186_emc *emc;
 	int err;

 	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
 	if (!emc)
 		return -ENOMEM;

 	emc->bpmp = tegra_bpmp_get(&pdev->dev);
 	if (IS_ERR(emc->bpmp))
 		return dev_err_probe(&pdev->dev, PTR_ERR(emc->bpmp), "failed to get BPMP\n");

 	emc->clk = devm_clk_get(&pdev->dev, "emc");
 	if (IS_ERR(emc->clk)) {
 		err = PTR_ERR(emc->clk);
 		dev_err(&pdev->dev, "failed to get EMC clock: %d\n", err);
 		goto put_bpmp;
 	}

 	platform_set_drvdata(pdev, emc);
 	emc->dev = &pdev->dev;

 	if (tegra_bpmp_mrq_is_supported(emc->bpmp, MRQ_EMC_DVFS_LATENCY)) {
 		err = tegra186_emc_get_emc_dvfs_latency(emc);
 		if (err)
 			goto put_bpmp;
 	}

 	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:
 	tegra_bpmp_put(emc->bpmp);
 	return err;
 }

 static void 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);
 }

 static const struct of_device_id tegra186_emc_of_match[] = {
 #if defined(CONFIG_ARCH_TEGRA_186_SOC)
 	{ .compatible = "nvidia,tegra186-emc" },
 #endif
 #if defined(CONFIG_ARCH_TEGRA_194_SOC)
 	{ .compatible = "nvidia,tegra194-emc" },
 #endif
 #if defined(CONFIG_ARCH_TEGRA_234_SOC)
 	{ .compatible = "nvidia,tegra234-emc" },
 #endif
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, tegra186_emc_of_match);

 static struct platform_driver tegra186_emc_driver = {
 	.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_new = tegra186_emc_remove,
 };
 module_platform_driver(tegra186_emc_driver);

 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
 MODULE_DESCRIPTION("NVIDIA Tegra186 External Memory Controller driver");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2019 NVIDIA CORPORATION. All rights reserved.
	*/

	#include <linux/clk.h>
	#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;
	unsigned long rate;
	};

	struct tegra186_emc {
	struct tegra_bpmp *bpmp;
	struct device *dev;
	struct clk *clk;

	struct tegra186_emc_dvfs *dvfs;
	unsigned int num_dvfs;

	struct {
	struct dentry *root;
	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
	*
	* The memory controller driver exposes some files in debugfs that can be used
	* to control the EMC frequency. The top-level directory can be found here:
	*
	* /sys/kernel/debug/emc
	*
	* It contains the following files:
	*
	* - available_rates: This file contains a list of valid, space-separated
	* EMC frequencies.
	*
	* - min_rate: Writing a value to this file sets the given frequency as the
	* floor of the permitted range. If this is higher than the currently
	* configured EMC frequency, this will cause the frequency to be
	* increased so that it stays within the valid range.
	*
	* - max_rate: Similarily to the min_rate file, writing a value to this file
	* sets the given frequency as the ceiling of the permitted range. If
	* the value is lower than the currently configured EMC frequency, this
	* will cause the frequency to be decreased so that it stays within the
	* valid range.
	*/

	static bool tegra186_emc_validate_rate(struct tegra186_emc *emc,
	unsigned long rate)
	{
	unsigned int i;

	for (i = 0; i < emc->num_dvfs; i++)
	if (rate == emc->dvfs[i].rate)
	return true;

	return false;
	}

	static int tegra186_emc_debug_available_rates_show(struct seq_file *s,
	void *data)
	{
	struct tegra186_emc *emc = s->private;
	const char *prefix = "";
	unsigned int i;

	for (i = 0; i < emc->num_dvfs; i++) {
	seq_printf(s, "%s%lu", prefix, emc->dvfs[i].rate);
	prefix = " ";
	}

	seq_puts(s, "\n");

	return 0;
	}
	DEFINE_SHOW_ATTRIBUTE(tegra186_emc_debug_available_rates);

	static int tegra186_emc_debug_min_rate_get(void data, u64 rate)
	{
	struct tegra186_emc *emc = data;

	*rate = emc->debugfs.min_rate;

	return 0;
	}

	static int tegra186_emc_debug_min_rate_set(void *data, u64 rate)
	{
	struct tegra186_emc *emc = data;
	int err;

	if (!tegra186_emc_validate_rate(emc, rate))
	return -EINVAL;

	err = clk_set_min_rate(emc->clk, rate);
	if (err < 0)
	return err;

	emc->debugfs.min_rate = rate;

	return 0;
	}

	DEFINE_DEBUGFS_ATTRIBUTE(tegra186_emc_debug_min_rate_fops,
	tegra186_emc_debug_min_rate_get,
	tegra186_emc_debug_min_rate_set, "%llu\n");

	static int tegra186_emc_debug_max_rate_get(void data, u64 rate)
	{
	struct tegra186_emc *emc = data;

	*rate = emc->debugfs.max_rate;

	return 0;
	}

	static int tegra186_emc_debug_max_rate_set(void *data, u64 rate)
	{
	struct tegra186_emc *emc = data;
	int err;

	if (!tegra186_emc_validate_rate(emc, rate))
	return -EINVAL;

	err = clk_set_max_rate(emc->clk, rate);
	if (err < 0)
	return err;

	emc->debugfs.max_rate = rate;

	return 0;
	}

	DEFINE_DEBUGFS_ATTRIBUTE(tegra186_emc_debug_max_rate_fops,
	tegra186_emc_debug_max_rate_get,
	tegra186_emc_debug_max_rate_set, "%llu\n");

	static int tegra186_emc_get_emc_dvfs_latency(struct tegra186_emc *emc)
	{
	struct mrq_emc_dvfs_latency_response response;
	struct tegra_bpmp_message msg;
	unsigned int i;
	int err;

	memset(&msg, 0, sizeof(msg));
	msg.mrq = MRQ_EMC_DVFS_LATENCY;
	msg.tx.data = NULL;
	msg.tx.size = 0;
	msg.rx.data = &response;
	msg.rx.size = sizeof(response);

	err = tegra_bpmp_transfer(emc->bpmp, &msg);
	if (err < 0) {
	dev_err(emc->dev, "failed to EMC DVFS pairs: %d\n", err);
	return err;
	}
	if (msg.rx.ret < 0) {
	dev_err(emc->dev, "EMC DVFS MRQ failed: %d (BPMP error code)\n", msg.rx.ret);
	return -EINVAL;
	}

	emc->debugfs.min_rate = ULONG_MAX;
	emc->debugfs.max_rate = 0;

	emc->num_dvfs = response.num_pairs;

	emc->dvfs = devm_kmalloc_array(emc->dev, emc->num_dvfs, sizeof(*emc->dvfs), GFP_KERNEL);
	if (!emc->dvfs)
	return -ENOMEM;

	dev_dbg(emc->dev, "%u DVFS pairs:\n", emc->num_dvfs);

	for (i = 0; i < emc->num_dvfs; i++) {
	emc->dvfs[i].rate = response.pairs[i].freq * 1000;
	emc->dvfs[i].latency = response.pairs[i].latency;

	if (emc->dvfs[i].rate < emc->debugfs.min_rate)
	emc->debugfs.min_rate = emc->dvfs[i].rate;

	if (emc->dvfs[i].rate > emc->debugfs.max_rate)
	emc->debugfs.max_rate = emc->dvfs[i].rate;

	dev_dbg(emc->dev, " %2u: %lu Hz -> %lu us\n", i,
	emc->dvfs[i].rate, emc->dvfs[i].latency);
	}

	err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate, emc->debugfs.max_rate);
	if (err < 0) {
	dev_err(emc->dev, "failed to set rate range [%lu-%lu] for %pC\n",
	emc->debugfs.min_rate, emc->debugfs.max_rate, emc->clk);
	return err;
	}

	emc->debugfs.root = debugfs_create_dir("emc", NULL);
	debugfs_create_file("available_rates", 0444, emc->debugfs.root, emc,
	&tegra186_emc_debug_available_rates_fops);
	debugfs_create_file("min_rate", 0644, emc->debugfs.root, emc,
	&tegra186_emc_debug_min_rate_fops);
	debugfs_create_file("max_rate", 0644, emc->debugfs.root, emc,
	&tegra186_emc_debug_max_rate_fops);

	return 0;
	}

	/*
	* 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(const 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 tegra186_emc *emc;
	int err;

	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
	if (!emc)
	return -ENOMEM;

	emc->bpmp = tegra_bpmp_get(&pdev->dev);
	if (IS_ERR(emc->bpmp))
	return dev_err_probe(&pdev->dev, PTR_ERR(emc->bpmp), "failed to get BPMP\n");

	emc->clk = devm_clk_get(&pdev->dev, "emc");
	if (IS_ERR(emc->clk)) {
	err = PTR_ERR(emc->clk);
	dev_err(&pdev->dev, "failed to get EMC clock: %d\n", err);
	goto put_bpmp;
	}

	platform_set_drvdata(pdev, emc);
	emc->dev = &pdev->dev;

	if (tegra_bpmp_mrq_is_supported(emc->bpmp, MRQ_EMC_DVFS_LATENCY)) {
	err = tegra186_emc_get_emc_dvfs_latency(emc);
	if (err)
	goto put_bpmp;
	}

	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:
	tegra_bpmp_put(emc->bpmp);
	return err;
	}

	static void 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);
	}

	static const struct of_device_id tegra186_emc_of_match[] = {
	#if defined(CONFIG_ARCH_TEGRA_186_SOC)
	{ .compatible = "nvidia,tegra186-emc" },
	#endif
	#if defined(CONFIG_ARCH_TEGRA_194_SOC)
	{ .compatible = "nvidia,tegra194-emc" },
	#endif
	#if defined(CONFIG_ARCH_TEGRA_234_SOC)
	{ .compatible = "nvidia,tegra234-emc" },
	#endif
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, tegra186_emc_of_match);

	static struct platform_driver tegra186_emc_driver = {
	.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_new = tegra186_emc_remove,
	};
	module_platform_driver(tegra186_emc_driver);

	MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
	MODULE_DESCRIPTION("NVIDIA Tegra186 External Memory Controller driver");