Now Internal and External Memory Controllers are memory interconnection
providers. This allows us to use interconnect API for tuning of memory
configuration. EMC driver now supports OPPs and DVFS.
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
drivers/memory/tegra/Kconfig | 3 +-
drivers/memory/tegra/tegra20-emc.c | 310 ++++++++++++++++++++++++++++-
drivers/memory/tegra/tegra20.c | 77 +++++++
3 files changed, 386 insertions(+), 4 deletions(-)
diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index ff426747cd7d..ac3dfe155505 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -11,7 +11,8 @@ config TEGRA_MC
config TEGRA20_EMC
tristate "NVIDIA Tegra20 External Memory Controller driver"
default y
- depends on ARCH_TEGRA_2x_SOC
+ depends on TEGRA_MC && ARCH_TEGRA_2x_SOC
+ select PM_OPP
help
This driver is for the External Memory Controller (EMC) found on
Tegra20 chips. The EMC controls the external DRAM on the board.
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index a49658d217a7..5e10aa97809f 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -9,18 +9,25 @@
#include <linux/clk/tegra.h>
#include <linux/debugfs.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.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"
+
#define EMC_INTSTATUS 0x000
#define EMC_INTMASK 0x004
#define EMC_DBG 0x008
@@ -62,6 +69,11 @@
#define EMC_ODT_READ 0x0b4
#define EMC_FBIO_CFG5 0x104
#define EMC_FBIO_CFG6 0x114
+#define EMC_STAT_CONTROL 0x160
+#define EMC_STAT_LLMC_CONTROL 0x178
+#define EMC_STAT_PWR_CLOCK_LIMIT 0x198
+#define EMC_STAT_PWR_CLOCKS 0x19c
+#define EMC_STAT_PWR_COUNT 0x1a0
#define EMC_AUTO_CAL_INTERVAL 0x2a8
#define EMC_CFG_2 0x2b8
#define EMC_CFG_DIG_DLL 0x2bc
@@ -88,6 +100,8 @@
#define EMC_DBG_READ_DQM_CTRL BIT(9)
#define EMC_DBG_CFG_PRIORITY BIT(24)
+#define EMC_FBIO_CFG5_DRAM_WIDTH_X16 BIT(4)
+
static const u16 emc_timing_registers[] = {
EMC_RC,
EMC_RFC,
@@ -142,11 +156,25 @@ struct emc_timing {
u32 data[ARRAY_SIZE(emc_timing_registers)];
};
+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;
+ unsigned int dram_bus_width;
struct emc_timing *timings;
unsigned int num_timings;
@@ -156,6 +184,15 @@ 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 irqreturn_t tegra_emc_isr(int irq, void *data)
@@ -413,7 +450,7 @@ tegra_emc_find_node_by_ram_code(struct device *dev)
static int emc_setup_hw(struct tegra_emc *emc)
{
u32 intmask = EMC_REFRESH_OVERFLOW_INT;
- u32 emc_cfg, emc_dbg;
+ u32 emc_cfg, emc_dbg, emc_fbio;
emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2);
@@ -444,6 +481,15 @@ static int emc_setup_hw(struct tegra_emc *emc)
emc_dbg &= ~EMC_DBG_FORCE_UPDATE;
writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
+ emc_fbio = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
+
+ if (emc_fbio & EMC_FBIO_CFG5_DRAM_WIDTH_X16)
+ emc->dram_bus_width = 16;
+ else
+ emc->dram_bus_width = 32;
+
+ dev_info(emc->dev, "%ubit DRAM bus\n", emc->dram_bus_width);
+
return 0;
}
@@ -488,6 +534,83 @@ 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
*
@@ -571,7 +694,7 @@ 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;
@@ -601,7 +724,7 @@ 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;
@@ -658,6 +781,177 @@ static void tegra_emc_debugfs_init(struct tegra_emc *emc)
emc, &tegra_emc_debug_max_rate_fops);
}
+static inline struct tegra_emc *
+to_tegra_emc_provider(struct icc_provider *provider)
+{
+ 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);
+ unsigned int dram_data_bus_width_bytes;
+ int err;
+
+ /*
+ * Tegra20 EMC runs on x2 clock rate of SDRAM bus because DDR data
+ * is sampled on both clock edges. This means that EMC clock rate
+ * equals to the peak data-rate.
+ */
+ dram_data_bus_width_bytes = emc->dram_bus_width / 8;
+ do_div(rate, 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;
+ struct icc_node *node;
+ int err;
+
+ emc->mc = devm_tegra_memory_controller_get(emc->dev);
+ if (IS_ERR(emc->mc))
+ return PTR_ERR(emc->mc);
+
+ soc = emc->mc->soc;
+
+ 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;
+ }
+
+ 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);
+
+ 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)
+{
+ struct opp_table *opp_table;
+ const char *rname = "core";
+ int err;
+
+ /*
+ * Legacy device-trees don't have OPP table and EMC driver isn't
+ * useful in this case.
+ */
+ if (!device_property_present(emc->dev, "operating-points-v2")) {
+ dev_err(emc->dev,
+ "OPP table not found, please update your device tree\n");
+ return -ENODEV;
+ }
+
+ /* voltage scaling is optional */
+ if (device_property_present(emc->dev, "core-supply"))
+ opp_table = dev_pm_opp_set_regulators(emc->dev, &rname, 1);
+ else
+ opp_table = dev_pm_opp_get_opp_table(emc->dev);
+
+ if (IS_ERR(opp_table))
+ return dev_err_probe(emc->dev, PTR_ERR(opp_table),
+ "failed to prepare OPP table\n");
+
+ err = dev_pm_opp_of_add_table(emc->dev);
+ if (err) {
+ dev_err(emc->dev, "failed to add OPP table: %d\n", err);
+ goto put_table;
+ }
+
+ dev_info(emc->dev, "current clock rate %lu MHz\n",
+ 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_table:
+ dev_pm_opp_put_regulators(opp_table);
+
+ return err;
+}
+
static int tegra_emc_probe(struct platform_device *pdev)
{
struct device_node *np;
@@ -674,6 +968,7 @@ static int tegra_emc_probe(struct platform_device *pdev)
if (!emc)
return -ENOMEM;
+ mutex_init(&emc->rate_lock);
emc->clk_nb.notifier_call = tegra_emc_clk_change_notify;
emc->dev = &pdev->dev;
@@ -716,8 +1011,14 @@ static int tegra_emc_probe(struct platform_device *pdev)
goto unset_cb;
}
+ err = tegra_emc_opp_table_init(emc);
+ if (err)
+ goto unreg_notifier;
+
platform_set_drvdata(pdev, emc);
+ tegra_emc_rate_requests_init(emc);
tegra_emc_debugfs_init(emc);
+ tegra_emc_interconnect_init(emc);
/*
* Don't allow the kernel module to be unloaded. Unloading adds some
@@ -728,6 +1029,8 @@ static int tegra_emc_probe(struct platform_device *pdev)
return 0;
+unreg_notifier:
+ clk_notifier_unregister(emc->clk, &emc->clk_nb);
unset_cb:
tegra20_clk_set_emc_round_callback(NULL, NULL);
@@ -746,6 +1049,7 @@ static struct platform_driver tegra_emc_driver = {
.name = "tegra20-emc",
.of_match_table = tegra_emc_of_match,
.suppress_bind_attrs = true,
+ .sync_state = icc_sync_state,
},
};
module_platform_driver(tegra_emc_driver);
diff --git a/drivers/memory/tegra/tegra20.c b/drivers/memory/tegra/tegra20.c
index a8098bff91d9..29ecf02805a0 100644
--- a/drivers/memory/tegra/tegra20.c
+++ b/drivers/memory/tegra/tegra20.c
@@ -3,6 +3,10 @@
* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
*/
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
#include <dt-bindings/memory/tegra20-mc.h>
#include "mc.h"
@@ -280,6 +284,78 @@ static const struct tegra_mc_reset_ops tegra20_mc_reset_ops = {
.reset_status = tegra20_mc_reset_status,
};
+static int tegra20_mc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+ /*
+ * It should be possible to tune arbitration knobs here, but the
+ * default values are known to work well on all devices. Hence
+ * nothing to do here so far.
+ */
+ return 0;
+}
+
+static int tegra20_mc_icc_aggreate(struct icc_node *node, u32 tag, u32 avg_bw,
+ u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
+{
+ /*
+ * ISO clients need to reserve extra bandwidth up-front because
+ * there could be high bandwidth pressure during initial filling
+ * of the client's FIFO buffers. Secondly, we need to take into
+ * account impurities of the memory subsystem.
+ */
+ if (tag & TEGRA_MC_ICC_TAG_ISO)
+ peak_bw = tegra_mc_scale_percents(peak_bw, 300);
+
+ *agg_avg += avg_bw;
+ *agg_peak = max(*agg_peak, peak_bw);
+
+ return 0;
+}
+
+static struct icc_node_data *
+tegra20_mc_of_icc_xlate_extended(struct of_phandle_args *spec, void *data)
+{
+ struct tegra_mc *mc = icc_provider_to_tegra_mc(data);
+ unsigned int i, idx = spec->args[0];
+ struct icc_node_data *ndata;
+ struct icc_node *node;
+
+ list_for_each_entry(node, &mc->provider.nodes, node_list) {
+ if (node->id != idx)
+ continue;
+
+ ndata = kzalloc(sizeof(*ndata), GFP_KERNEL);
+ if (!ndata)
+ return ERR_PTR(-ENOMEM);
+
+ ndata->node = node;
+
+ /* these clients are isochronous by default */
+ if (strstarts(node->name, "display") ||
+ strstarts(node->name, "vi"))
+ ndata->tag = TEGRA_MC_ICC_TAG_ISO;
+ else
+ ndata->tag = TEGRA_MC_ICC_TAG_DEFAULT;
+
+ return ndata;
+ }
+
+ for (i = 0; i < mc->soc->num_clients; i++) {
+ if (mc->soc->clients[i].id == idx)
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ dev_err(mc->dev, "invalid ICC client ID %u\n", idx);
+
+ return ERR_PTR(-EINVAL);
+}
+
+static const struct tegra_mc_icc_ops tegra20_mc_icc_ops = {
+ .xlate_extended = tegra20_mc_of_icc_xlate_extended,
+ .aggregate = tegra20_mc_icc_aggreate,
+ .set = tegra20_mc_icc_set,
+};
+
const struct tegra_mc_soc tegra20_mc_soc = {
.clients = tegra20_mc_clients,
.num_clients = ARRAY_SIZE(tegra20_mc_clients),
@@ -290,4 +366,5 @@ const struct tegra_mc_soc tegra20_mc_soc = {
.reset_ops = &tegra20_mc_reset_ops,
.resets = tegra20_mc_resets,
.num_resets = ARRAY_SIZE(tegra20_mc_resets),
+ .icc_ops = &tegra20_mc_icc_ops,
};
--
2.27.0
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