mmc: sdhci-xenon: use clk only with DT

As a preparation for supporting ACPI, modify the driver
to use the clk framework only when booting with DT -
otherwise rely on the configuration done by firmware.
For that purpose introduce also a custom SDHCI get_max_clock
callback.

Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/r/20201204171626.10935-4-mw@semihalf.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: wojtas-marcin

drivers/mmc/host/sdhci-xenon.c

@@ -247,14 +247,24 @@ static void xenon_voltage_switch(struct sdhci_host *host)
 	sdhci_readw(host, SDHCI_HOST_CONTROL2);
 }
 
+static unsigned int xenon_get_max_clock(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	if (pltfm_host->clk)
+		return sdhci_pltfm_clk_get_max_clock(host);
+	else
+		return pltfm_host->clock;
+}
+
 static const struct sdhci_ops sdhci_xenon_ops = {
 	.voltage_switch		= xenon_voltage_switch,
 	.set_clock		= sdhci_set_clock,
 	.set_power		= xenon_set_power,
 	.set_bus_width		= sdhci_set_bus_width,
 	.reset			= xenon_reset,
 	.set_uhs_signaling	= xenon_set_uhs_signaling,
-	.get_max_clock		= sdhci_pltfm_clk_get_max_clock,
+	.get_max_clock		= xenon_get_max_clock,
 };
 
 static const struct sdhci_pltfm_data sdhci_xenon_pdata = {
@@ -483,6 +493,7 @@ static void xenon_sdhc_unprepare(struct sdhci_host *host)
 static int xenon_probe(struct platform_device *pdev)
 {
 	struct sdhci_pltfm_host *pltfm_host;
+	struct device *dev = &pdev->dev;
 	struct sdhci_host *host;
 	struct xenon_priv *priv;
 	int err;
@@ -503,25 +514,27 @@ static int xenon_probe(struct platform_device *pdev)
 	 */
 	xenon_replace_mmc_host_ops(host);
 
-	pltfm_host->clk = devm_clk_get(&pdev->dev, "core");
-	if (IS_ERR(pltfm_host->clk)) {
-		err = PTR_ERR(pltfm_host->clk);
-		dev_err(&pdev->dev, "Failed to setup input clk: %d\n", err);
-		goto free_pltfm;
-	}
-	err = clk_prepare_enable(pltfm_host->clk);
-	if (err)
-		goto free_pltfm;
-
-	priv->axi_clk = devm_clk_get(&pdev->dev, "axi");
-	if (IS_ERR(priv->axi_clk)) {
-		err = PTR_ERR(priv->axi_clk);
-		if (err == -EPROBE_DEFER)
-			goto err_clk;
-	} else {
-		err = clk_prepare_enable(priv->axi_clk);
+	if (dev->of_node) {
+		pltfm_host->clk = devm_clk_get(&pdev->dev, "core");
+		if (IS_ERR(pltfm_host->clk)) {
+			err = PTR_ERR(pltfm_host->clk);
+			dev_err(&pdev->dev, "Failed to setup input clk: %d\n", err);
+			goto free_pltfm;
+		}
+		err = clk_prepare_enable(pltfm_host->clk);
 		if (err)
-			goto err_clk;
+			goto free_pltfm;
+
+		priv->axi_clk = devm_clk_get(&pdev->dev, "axi");
+		if (IS_ERR(priv->axi_clk)) {
+			err = PTR_ERR(priv->axi_clk);
+			if (err == -EPROBE_DEFER)
+				goto err_clk;
+		} else {
+			err = clk_prepare_enable(priv->axi_clk);
+			if (err)
+				goto err_clk;
+		}
 	}
 
 	err = mmc_of_parse(host->mmc);