mmc: tegra: Add and use tegra_sdhci_get_max_clock()

Implement and use tegra_sdhci_get_max_clock() which returns the true
maximum host clock rate. The issue with tegra_sdhci_get_max_clock() is
that it returns the current clock rate of the host instead of the
maximum one, which can lead to unnecessarily small clock rates.

This differs from the previous implementation of
tegra_sdhci_get_max_clock() in that it doesn't divide the result by two.

Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-tegra.c

@@ -235,6 +235,13 @@ static void tegra_sdhci_set_uhs_signaling(struct sdhci_host *host,
 	sdhci_set_uhs_signaling(host, timing);
 }
 
+static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	return clk_round_rate(pltfm_host->clk, UINT_MAX);
+}
+
 static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap)
 {
 	u32 reg;
@@ -299,7 +306,7 @@ static const struct sdhci_ops tegra_sdhci_ops = {
 	.platform_execute_tuning = tegra_sdhci_execute_tuning,
 	.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
 	.voltage_switch = tegra_sdhci_voltage_switch,
-	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
+	.get_max_clock = tegra_sdhci_get_max_clock,
 };
 
 static const struct sdhci_pltfm_data sdhci_tegra20_pdata = {
@@ -356,7 +363,7 @@ static const struct sdhci_ops tegra114_sdhci_ops = {
 	.platform_execute_tuning = tegra_sdhci_execute_tuning,
 	.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
 	.voltage_switch = tegra_sdhci_voltage_switch,
-	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
+	.get_max_clock = tegra_sdhci_get_max_clock,
 };
 
 static const struct sdhci_pltfm_data sdhci_tegra114_pdata = {