memory: tegra: Adapt for Tegra20 clock driver changes

Now Tegra20 and Tegra30 EMC drivers should provide clock-rounding
functionality using the new Tegra clock driver API.
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/memory/tegra/tegra20-emc.c

@@ -6,6 +6,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/clk/tegra.h>
 #include <linux/completion.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
@@ -421,6 +422,44 @@ static int emc_setup_hw(struct tegra_emc *emc)
 	return 0;
 }
 
+static long emc_round_rate(unsigned long rate,
+			   unsigned long min_rate,
+			   unsigned long max_rate,
+			   void *arg)
+{
+	struct emc_timing *timing = NULL;
+	struct tegra_emc *emc = arg;
+	unsigned int i;
+
+	min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);
+
+	for (i = 0; i < emc->num_timings; i++) {
+		if (emc->timings[i].rate < rate && i != emc->num_timings - 1)
+			continue;
+
+		if (emc->timings[i].rate > max_rate) {
+			i = max(i, 1u) - 1;
+
+			if (emc->timings[i].rate < min_rate)
+				break;
+		}
+
+		if (emc->timings[i].rate < min_rate)
+			continue;
+
+		timing = &emc->timings[i];
+		break;
+	}
+
+	if (!timing) {
+		dev_err(emc->dev, "no timing for rate %lu min %lu max %lu\n",
+			rate, min_rate, max_rate);
+		return -EINVAL;
+	}
+
+	return timing->rate;
+}
+
 static int tegra_emc_probe(struct platform_device *pdev)
 {
 	struct device_node *np;
@@ -477,21 +516,28 @@ 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);
-		return err;
+		goto unset_cb;
 	}
 
 	err = clk_notifier_register(emc->clk, &emc->clk_nb);
 	if (err) {
 		dev_err(&pdev->dev, "failed to register clk notifier: %d\n",
 			err);
-		return err;
+		goto unset_cb;
 	}
 
 	return 0;
+
+unset_cb:
+	tegra20_clk_set_emc_round_callback(NULL, NULL);
+
+	return err;
 }
 
 static const struct of_device_id tegra_emc_of_match[] = {