mmc: socfpga: Add clock framework support

Add support for fetching the clock frequency both using the legacy
method in case clock framework is disabled as well as via the clock
framework if it is enabled. This allows for migration to the clock
framework on platforms which supports it while not breaking legacy
platforms. That said, the legacy method must be removed eventually.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <chin.liang.see@intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>

drivers/mmc/socfpga_dw_mmc.c

@@ -6,6 +6,7 @@
 #include <common.h>
 #include <asm/arch/clock_manager.h>
 #include <asm/arch/system_manager.h>
+#include <clk.h>
 #include <dm.h>
 #include <dwmmc.h>
 #include <errno.h>
@@ -70,20 +71,39 @@ static void socfpga_dwmci_clksel(struct dwmci_host *host)
 		CLKMGR_PERPLLGRP_EN_SDMMCCLK_MASK);
 }
 
-static int socfpga_dwmmc_ofdata_to_platdata(struct udevice *dev)
+static int socfpga_dwmmc_get_clk_rate(struct udevice *dev)
 {
-	/* FIXME: probe from DT eventually too/ */
-	const unsigned long clk = cm_get_mmc_controller_clk_hz();
-
 	struct dwmci_socfpga_priv_data *priv = dev_get_priv(dev);
 	struct dwmci_host *host = &priv->host;
-	int fifo_depth;
+#if CONFIG_IS_ENABLED(CLK)
+	struct clk clk;
+	int ret;
+
+	ret = clk_get_by_index(dev, 1, &clk);
+	if (ret)
+		return ret;
 
-	if (clk == 0) {
+	host->bus_hz = clk_get_rate(&clk);
+
+	clk_free(&clk);
+#else
+	/* Fixed clock divide by 4 which due to the SDMMC wrapper */
+	host->bus_hz = cm_get_mmc_controller_clk_hz();
+#endif
+	if (host->bus_hz == 0) {
 		printf("DWMMC: MMC clock is zero!");
 		return -EINVAL;
 	}
 
+	return 0;
+}
+
+static int socfpga_dwmmc_ofdata_to_platdata(struct udevice *dev)
+{
+	struct dwmci_socfpga_priv_data *priv = dev_get_priv(dev);
+	struct dwmci_host *host = &priv->host;
+	int fifo_depth;
+
 	fifo_depth = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
 				    "fifo-depth", 0);
 	if (fifo_depth < 0) {
@@ -102,8 +122,6 @@ static int socfpga_dwmmc_ofdata_to_platdata(struct udevice *dev)
 	 * We only have one dwmmc block on gen5 SoCFPGA.
 	 */
 	host->dev_index = 0;
-	/* Fixed clock divide by 4 which due to the SDMMC wrapper */
-	host->bus_hz = clk;
 	host->fifoth_val = MSIZE(0x2) |
 		RX_WMARK(fifo_depth / 2 - 1) | TX_WMARK(fifo_depth / 2);
 	priv->drvsel = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
@@ -123,6 +141,11 @@ static int socfpga_dwmmc_probe(struct udevice *dev)
 	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
 	struct dwmci_socfpga_priv_data *priv = dev_get_priv(dev);
 	struct dwmci_host *host = &priv->host;
+	int ret;
+
+	ret = socfpga_dwmmc_get_clk_rate(dev);
+	if (ret)
+		return ret;
 
 	socfpga_dwmci_reset(dev);
 
@@ -130,7 +153,6 @@ static int socfpga_dwmmc_probe(struct udevice *dev)
 	dwmci_setup_cfg(&plat->cfg, host, host->bus_hz, 400000);
 	host->mmc = &plat->mmc;
 #else
-	int ret;
 
 	ret = add_dwmci(host, host->bus_hz, 400000);
 	if (ret)