1 files changed, 353 insertions, 58 deletions

diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index 055af0e08a2e..44ac155936aa 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -14,16 +14,21 @@
 #include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <linux/interconnect-provider.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
 #include <linux/sort.h>
 #include <linux/types.h>
 
+#include <soc/tegra/common.h>
 #include <soc/tegra/fuse.h>
 
 #include "mc.h"
@@ -323,9 +328,21 @@ struct emc_timing {
 	bool emc_cfg_dyn_self_ref;
 };
 
+enum emc_rate_request_type {
+	EMC_RATE_DEBUG,
+	EMC_RATE_ICC,
+	EMC_RATE_TYPE_MAX,
+};
+
+struct emc_rate_request {
+	unsigned long min_rate;
+	unsigned long max_rate;
+};
+
 struct tegra_emc {
 	struct device *dev;
 	struct tegra_mc *mc;
+	struct icc_provider provider;
 	struct notifier_block clk_nb;
 	struct clk *clk;
 	void __iomem *regs;
@@ -352,6 +369,15 @@ struct tegra_emc {
 		unsigned long min_rate;
 		unsigned long max_rate;
 	} debugfs;
+
+	/*
+	 * There are multiple sources in the EMC driver which could request
+	 * a min/max clock rate, these rates are contained in this array.
+	 */
+	struct emc_rate_request requested_rate[EMC_RATE_TYPE_MAX];
+
+	/* protect shared rate-change code path */
+	struct mutex rate_lock;
 };
 
 static int emc_seq_update_timing(struct tegra_emc *emc)
@@ -988,6 +1014,11 @@ static struct device_node *emc_find_node_by_ram_code(struct device *dev)
 	u32 value, ram_code;
 	int err;
 
+	if (of_get_child_count(dev->of_node) == 0) {
+		dev_info(dev, "device-tree doesn't have memory timings\n");
+		return NULL;
+	}
+
 	ram_code = tegra_read_ram_code();
 
 	for_each_child_of_node(dev->of_node, np) {
@@ -1057,6 +1088,9 @@ static long emc_round_rate(unsigned long rate,
 	struct tegra_emc *emc = arg;
 	unsigned int i;
 
+	if (!emc->num_timings)
+		return clk_get_rate(emc->clk);
+
 	min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);
 
 	for (i = 0; i < emc->num_timings; i++) {
@@ -1086,6 +1120,83 @@ static long emc_round_rate(unsigned long rate,
 	return timing->rate;
 }
 
+static void tegra_emc_rate_requests_init(struct tegra_emc *emc)
+{
+	unsigned int i;
+
+	for (i = 0; i < EMC_RATE_TYPE_MAX; i++) {
+		emc->requested_rate[i].min_rate = 0;
+		emc->requested_rate[i].max_rate = ULONG_MAX;
+	}
+}
+
+static int emc_request_rate(struct tegra_emc *emc,
+			    unsigned long new_min_rate,
+			    unsigned long new_max_rate,
+			    enum emc_rate_request_type type)
+{
+	struct emc_rate_request *req = emc->requested_rate;
+	unsigned long min_rate = 0, max_rate = ULONG_MAX;
+	unsigned int i;
+	int err;
+
+	/* select minimum and maximum rates among the requested rates */
+	for (i = 0; i < EMC_RATE_TYPE_MAX; i++, req++) {
+		if (i == type) {
+			min_rate = max(new_min_rate, min_rate);
+			max_rate = min(new_max_rate, max_rate);
+		} else {
+			min_rate = max(req->min_rate, min_rate);
+			max_rate = min(req->max_rate, max_rate);
+		}
+	}
+
+	if (min_rate > max_rate) {
+		dev_err_ratelimited(emc->dev, "%s: type %u: out of range: %lu %lu\n",
+				    __func__, type, min_rate, max_rate);
+		return -ERANGE;
+	}
+
+	/*
+	 * EMC rate-changes should go via OPP API because it manages voltage
+	 * changes.
+	 */
+	err = dev_pm_opp_set_rate(emc->dev, min_rate);
+	if (err)
+		return err;
+
+	emc->requested_rate[type].min_rate = new_min_rate;
+	emc->requested_rate[type].max_rate = new_max_rate;
+
+	return 0;
+}
+
+static int emc_set_min_rate(struct tegra_emc *emc, unsigned long rate,
+			    enum emc_rate_request_type type)
+{
+	struct emc_rate_request *req = &emc->requested_rate[type];
+	int ret;
+
+	mutex_lock(&emc->rate_lock);
+	ret = emc_request_rate(emc, rate, req->max_rate, type);
+	mutex_unlock(&emc->rate_lock);
+
+	return ret;
+}
+
+static int emc_set_max_rate(struct tegra_emc *emc, unsigned long rate,
+			    enum emc_rate_request_type type)
+{
+	struct emc_rate_request *req = &emc->requested_rate[type];
+	int ret;
+
+	mutex_lock(&emc->rate_lock);
+	ret = emc_request_rate(emc, req->min_rate, rate, type);
+	mutex_unlock(&emc->rate_lock);
+
+	return ret;
+}
+
 /*
  * debugfs interface
  *
@@ -1169,7 +1280,7 @@ static int tegra_emc_debug_min_rate_set(void *data, u64 rate)
 	if (!tegra_emc_validate_rate(emc, rate))
 		return -EINVAL;
 
-	err = clk_set_min_rate(emc->clk, rate);
+	err = emc_set_min_rate(emc, rate, EMC_RATE_DEBUG);
 	if (err < 0)
 		return err;
 
@@ -1199,7 +1310,7 @@ static int tegra_emc_debug_max_rate_set(void *data, u64 rate)
 	if (!tegra_emc_validate_rate(emc, rate))
 		return -EINVAL;
 
-	err = clk_set_max_rate(emc->clk, rate);
+	err = emc_set_max_rate(emc, rate, EMC_RATE_DEBUG);
 	if (err < 0)
 		return err;
 
@@ -1256,51 +1367,239 @@ static void tegra_emc_debugfs_init(struct tegra_emc *emc)
 			    emc, &tegra_emc_debug_max_rate_fops);
 }
 
-static int tegra_emc_probe(struct platform_device *pdev)
+static inline struct tegra_emc *
+to_tegra_emc_provider(struct icc_provider *provider)
 {
-	struct platform_device *mc;
-	struct device_node *np;
-	struct tegra_emc *emc;
+	return container_of(provider, struct tegra_emc, provider);
+}
+
+static struct icc_node_data *
+emc_of_icc_xlate_extended(struct of_phandle_args *spec, void *data)
+{
+	struct icc_provider *provider = data;
+	struct icc_node_data *ndata;
+	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;
+
+		ndata = kzalloc(sizeof(*ndata), GFP_KERNEL);
+		if (!ndata)
+			return ERR_PTR(-ENOMEM);
+
+		/*
+		 * SRC and DST nodes should have matching TAG in order to have
+		 * it set by default for a requested path.
+		 */
+		ndata->tag = TEGRA_MC_ICC_TAG_ISO;
+		ndata->node = node;
+
+		return ndata;
+	}
+
+	return ERR_PTR(-EPROBE_DEFER);
+}
+
+static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+	struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
+	unsigned long long peak_bw = icc_units_to_bps(dst->peak_bw);
+	unsigned long long avg_bw = icc_units_to_bps(dst->avg_bw);
+	unsigned long long rate = max(avg_bw, peak_bw);
+	const unsigned int dram_data_bus_width_bytes = 4;
+	const unsigned int ddr = 2;
+	int err;
+
+	/*
+	 * Tegra30 EMC runs on a clock rate of SDRAM bus.  This means that
+	 * EMC clock rate is twice smaller than the peak data rate because
+	 * data is sampled on both EMC clock edges.
+	 */
+	do_div(rate, ddr * dram_data_bus_width_bytes);
+	rate = min_t(u64, rate, U32_MAX);
+
+	err = emc_set_min_rate(emc, rate, EMC_RATE_ICC);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int tegra_emc_interconnect_init(struct tegra_emc *emc)
+{
+	const struct tegra_mc_soc *soc = emc->mc->soc;
+	struct icc_node *node;
 	int err;
 
-	if (of_get_child_count(pdev->dev.of_node) == 0) {
-		dev_info(&pdev->dev,
-			 "device-tree node doesn't have memory timings\n");
-		return -ENODEV;
+	emc->provider.dev = emc->dev;
+	emc->provider.set = emc_icc_set;
+	emc->provider.data = &emc->provider;
+	emc->provider.aggregate = soc->icc_ops->aggregate;
+	emc->provider.xlate_extended = emc_of_icc_xlate_extended;
+
+	err = icc_provider_add(&emc->provider);
+	if (err)
+		goto err_msg;
+
+	/* create External Memory Controller node */
+	node = icc_node_create(TEGRA_ICC_EMC);
+	if (IS_ERR(node)) {
+		err = PTR_ERR(node);
+		goto del_provider;
 	}
 
-	np = of_parse_phandle(pdev->dev.of_node, "nvidia,memory-controller", 0);
-	if (!np) {
-		dev_err(&pdev->dev, "could not get memory controller node\n");
-		return -ENOENT;
+	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;
 	}
 
-	mc = of_find_device_by_node(np);
-	of_node_put(np);
-	if (!mc)
-		return -ENOENT;
+	node->name = "External Memory (DRAM)";
+	icc_node_add(node, &emc->provider);
 
-	np = emc_find_node_by_ram_code(&pdev->dev);
-	if (!np)
-		return -EINVAL;
+	return 0;
+
+remove_nodes:
+	icc_nodes_remove(&emc->provider);
+del_provider:
+	icc_provider_del(&emc->provider);
+err_msg:
+	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
+
+	return err;
+}
+
+static int tegra_emc_opp_table_init(struct tegra_emc *emc)
+{
+	u32 hw_version = BIT(tegra_sku_info.soc_speedo_id);
+	struct opp_table *clk_opp_table, *hw_opp_table;
+	int err;
+
+	clk_opp_table = dev_pm_opp_set_clkname(emc->dev, NULL);
+	err = PTR_ERR_OR_ZERO(clk_opp_table);
+	if (err) {
+		dev_err(emc->dev, "failed to set OPP clk: %d\n", err);
+		return err;
+	}
+
+	hw_opp_table = dev_pm_opp_set_supported_hw(emc->dev, &hw_version, 1);
+	err = PTR_ERR_OR_ZERO(hw_opp_table);
+	if (err) {
+		dev_err(emc->dev, "failed to set OPP supported HW: %d\n", err);
+		goto put_clk_table;
+	}
+
+	err = dev_pm_opp_of_add_table(emc->dev);
+	if (err) {
+		if (err == -ENODEV)
+			dev_err(emc->dev, "OPP table not found, please update your device tree\n");
+		else
+			dev_err(emc->dev, "failed to add OPP table: %d\n", err);
+
+		goto put_hw_table;
+	}
+
+	dev_info(emc->dev, "OPP HW ver. 0x%x, current clock rate %lu MHz\n",
+		 hw_version, clk_get_rate(emc->clk) / 1000000);
+
+	/* first dummy rate-set initializes voltage state */
+	err = dev_pm_opp_set_rate(emc->dev, clk_get_rate(emc->clk));
+	if (err) {
+		dev_err(emc->dev, "failed to initialize OPP clock: %d\n", err);
+		goto remove_table;
+	}
+
+	return 0;
+
+remove_table:
+	dev_pm_opp_of_remove_table(emc->dev);
+put_hw_table:
+	dev_pm_opp_put_supported_hw(hw_opp_table);
+put_clk_table:
+	dev_pm_opp_put_clkname(clk_opp_table);
+
+	return err;
+}
+
+static void devm_tegra_emc_unset_callback(void *data)
+{
+	tegra20_clk_set_emc_round_callback(NULL, NULL);
+}
+
+static void devm_tegra_emc_unreg_clk_notifier(void *data)
+{
+	struct tegra_emc *emc = data;
+
+	clk_notifier_unregister(emc->clk, &emc->clk_nb);
+}
+
+static int tegra_emc_init_clk(struct tegra_emc *emc)
+{
+	int err;
+
+	tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
+
+	err = devm_add_action_or_reset(emc->dev, devm_tegra_emc_unset_callback,
+				       NULL);
+	if (err)
+		return err;
+
+	emc->clk = devm_clk_get(emc->dev, NULL);
+	if (IS_ERR(emc->clk)) {
+		dev_err(emc->dev, "failed to get EMC clock: %pe\n", emc->clk);
+		return PTR_ERR(emc->clk);
+	}
+
+	err = clk_notifier_register(emc->clk, &emc->clk_nb);
+	if (err) {
+		dev_err(emc->dev, "failed to register clk notifier: %d\n", err);
+		return err;
+	}
+
+	err = devm_add_action_or_reset(emc->dev,
+				       devm_tegra_emc_unreg_clk_notifier, emc);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int tegra_emc_probe(struct platform_device *pdev)
+{
+	struct device_node *np;
+	struct tegra_emc *emc;
+	int err;
 
 	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
-	if (!emc) {
-		of_node_put(np);
+	if (!emc)
 		return -ENOMEM;
-	}
 
-	emc->mc = platform_get_drvdata(mc);
-	if (!emc->mc)
-		return -EPROBE_DEFER;
+	emc->mc = devm_tegra_memory_controller_get(&pdev->dev);
+	if (IS_ERR(emc->mc))
+		return PTR_ERR(emc->mc);
 
+	mutex_init(&emc->rate_lock);
 	emc->clk_nb.notifier_call = emc_clk_change_notify;
 	emc->dev = &pdev->dev;
 
-	err = emc_load_timings_from_dt(emc, np);
-	of_node_put(np);
-	if (err)
-		return err;
+	np = emc_find_node_by_ram_code(&pdev->dev);
+	if (np) {
+		err = emc_load_timings_from_dt(emc, np);
+		of_node_put(np);
+		if (err)
+			return err;
+	}
 
 	emc->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(emc->regs))
@@ -1311,10 +1610,9 @@ static int tegra_emc_probe(struct platform_device *pdev)
 		return err;
 
 	err = platform_get_irq(pdev, 0);
-	if (err < 0) {
-		dev_err(&pdev->dev, "interrupt not specified: %d\n", err);
+	if (err < 0)
 		return err;
-	}
+
 	emc->irq = err;
 
 	err = devm_request_irq(&pdev->dev, emc->irq, tegra_emc_isr, 0,
@@ -1324,31 +1622,27 @@ static int tegra_emc_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
-
-	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 unset_cb;
-	}
+	err = tegra_emc_init_clk(emc);
+	if (err)
+		return err;
 
-	err = clk_notifier_register(emc->clk, &emc->clk_nb);
-	if (err) {
-		dev_err(&pdev->dev, "failed to register clk notifier: %d\n",
-			err);
-		goto unset_cb;
-	}
+	err = tegra_emc_opp_table_init(emc);
+	if (err)
+		return err;
 
 	platform_set_drvdata(pdev, emc);
+	tegra_emc_rate_requests_init(emc);
 	tegra_emc_debugfs_init(emc);
+	tegra_emc_interconnect_init(emc);
 
-	return 0;
-
-unset_cb:
-	tegra20_clk_set_emc_round_callback(NULL, NULL);
+	/*
+	 * Don't allow the kernel module to be unloaded. Unloading adds some
+	 * extra complexity which doesn't really worth the effort in a case of
+	 * this driver.
+	 */
+	try_module_get(THIS_MODULE);
 
-	return err;
+	return 0;
 }
 
 static int tegra_emc_suspend(struct device *dev)
@@ -1393,6 +1687,7 @@ static const struct of_device_id tegra_emc_of_match[] = {
 	{ .compatible = "nvidia,tegra30-emc", },
 	{},
 };
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
 
 static struct platform_driver tegra_emc_driver = {
 	.probe = tegra_emc_probe,
@@ -1401,11 +1696,11 @@ static struct platform_driver tegra_emc_driver = {
 		.of_match_table = tegra_emc_of_match,
 		.pm = &tegra_emc_pm_ops,
 		.suppress_bind_attrs = true,
+		.sync_state = icc_sync_state,
 	},
 };
+module_platform_driver(tegra_emc_driver);
 
-static int __init tegra_emc_init(void)
-{
-	return platform_driver_register(&tegra_emc_driver);
-}
-subsys_initcall(tegra_emc_init);
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra30 EMC driver");
+MODULE_LICENSE("GPL v2");