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 digetx@gmail.com --- drivers/memory/tegra/tegra20-emc.c | 115 +++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+)
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c index 8d1967f4b4aa..2281bf9b784b 100644 --- a/drivers/memory/tegra/tegra20-emc.c +++ b/drivers/memory/tegra/tegra20-emc.c @@ -9,6 +9,7 @@ #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> @@ -148,6 +149,7 @@ struct emc_timing { struct tegra_emc { struct device *dev; struct notifier_block clk_nb; + struct icc_provider provider; struct clk *clk; void __iomem *regs;
@@ -661,6 +663,112 @@ 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 * +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) + return node; + } + + return ERR_PTR(-EINVAL); +} + +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 rate = icc_units_to_bps(dst->avg_bw); + unsigned int dram_data_bus_width_bytes = 4; + unsigned int ddr = 2; + int err; + + do_div(rate, ddr * dram_data_bus_width_bytes); + rate = min_t(u64, rate, U32_MAX); + + err = clk_set_min_rate(emc->clk, rate); + if (err) + return err; + + err = clk_set_rate(emc->clk, rate); + if (err) + return err; + + return 0; +} + +static int emc_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; +} + +static int tegra_emc_interconnect_init(struct tegra_emc *emc) +{ + struct icc_node *node; + int err; + + /* older device-trees don't have interconnect properties */ + if (!of_find_property(emc->dev->of_node, "#interconnect-cells", NULL)) + return 0; + + emc->provider.dev = emc->dev; + emc->provider.set = emc_icc_set; + emc->provider.data = &emc->provider; + emc->provider.xlate = emc_of_icc_xlate; + emc->provider.aggregate = emc_icc_aggregate; + + err = icc_provider_add(&emc->provider); + if (err) + return err; + + /* create External Memory Controller node */ + node = icc_node_create(TEGRA_ICC_EMC); + err = PTR_ERR_OR_ZERO(node); + if (err) + 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); + err = PTR_ERR_OR_ZERO(node); + if (err) + 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); + + return err; +} + static int tegra_emc_init_mc_timings(struct tegra_emc *emc) { struct tegra_mc_timing *timing; @@ -767,6 +875,13 @@ static int tegra_emc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, emc); tegra_emc_debugfs_init(emc);
+ if (IS_ENABLED(CONFIG_INTERCONNECT)) { + err = tegra_emc_interconnect_init(emc); + if (err) + dev_err(&pdev->dev, "failed to initialize ICC: %d\n", + err); + } + /* * 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