soc: mediatek: mtk-dvfsrc: Get and Enable DVFSRC clock

The DVFSRC has a clock on all platforms.

Get and enable it in the probe function, so that Linux's common clock
framework knows we're a user of it.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Author: Nicolas Frattaroli

drivers/soc/mediatek/mtk-dvfsrc.c

@@ -7,6 +7,7 @@
 
 #include <linux/arm-smccc.h>
 #include <linux/bitfield.h>
+#include <linux/clk.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -83,6 +84,7 @@ struct dvfsrc_opp_desc {
 struct dvfsrc_soc_data;
 struct mtk_dvfsrc {
 	struct device *dev;
+	struct clk *clk;
 	struct platform_device *icc;
 	struct platform_device *regulator;
 	const struct dvfsrc_soc_data *dvd;
@@ -650,6 +652,11 @@ static int mtk_dvfsrc_probe(struct platform_device *pdev)
 	if (IS_ERR(dvfsrc->regs))
 		return PTR_ERR(dvfsrc->regs);
 
+	dvfsrc->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(dvfsrc->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(dvfsrc->clk),
+				     "Couldn't get and enable DVFSRC clock\n");
+
 	arm_smccc_smc(MTK_SIP_DVFSRC_VCOREFS_CONTROL, MTK_SIP_DVFSRC_INIT,
 		      0, 0, 0, 0, 0, 0, &ares);
 	if (ares.a0)