Re: [PATCH v5 33/36] memory: tegra30-emc: Register as interconnect provider

2020-09-10 Thread Georgi Djakov
On 8/14/20 03:06, Dmitry Osipenko wrote:
> Now external memory controller is a memory interconnection provider.
> This allows us to use interconnect API to change memory configuration.
> 
> Signed-off-by: Dmitry Osipenko 

Acked-by: Georgi Djakov 
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[PATCH v5 33/36] memory: tegra30-emc: Register as interconnect provider

2020-08-17 Thread Dmitry Osipenko
Now external memory controller is a memory interconnection provider.
This allows us to use interconnect API to change memory configuration.

Signed-off-by: Dmitry Osipenko 
---
 drivers/memory/tegra/tegra30-emc.c | 110 +
 1 file changed, 110 insertions(+)

diff --git a/drivers/memory/tegra/tegra30-emc.c 
b/drivers/memory/tegra/tegra30-emc.c
index 0cd39bf5f393..29448d02f750 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -14,6 +14,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -327,6 +328,7 @@ struct tegra_emc {
struct device *dev;
struct tegra_mc *mc;
struct notifier_block clk_nb;
+   struct icc_provider provider;
struct clk *clk;
void __iomem *regs;
unsigned int irq;
@@ -1264,6 +1266,113 @@ 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)
+   goto err_msg;
+
+   /* 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);
+err_msg:
+   dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
+
+   return err;
+}
+
 static int tegra_emc_probe(struct platform_device *pdev)
 {
struct platform_device *mc;
@@ -1343,6 +1452,7 @@ static int tegra_emc_probe(struct platform_device *pdev)
 
platform_set_drvdata(pdev, emc);
tegra_emc_debugfs_init(emc);
+   tegra_emc_interconnect_init(emc);
 
/*
 * Don't allow the kernel module to be unloaded. Unloading adds some
-- 
2.27.0

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