[v1,01/20] clk: imx: add clk-gpr-mux driver

diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile
index e8aacb0ee6ac..a75d59f7cb8a 100644
--- a/drivers/clk/imx/Makefile
+++ b/drivers/clk/imx/Makefile
@@ -22,6 +22,7 @@  mxc-clk-objs += clk-pllv3.o
 mxc-clk-objs += clk-pllv4.o
 mxc-clk-objs += clk-pll14xx.o
 mxc-clk-objs += clk-sscg-pll.o
+mxc-clk-objs += clk-gpr-mux.o
 obj-$(CONFIG_MXC_CLK) += mxc-clk.o
 
 obj-$(CONFIG_CLK_IMX8MM) += clk-imx8mm.o
diff --git a/drivers/clk/imx/clk-gpr-mux.c b/drivers/clk/imx/clk-gpr-mux.c
new file mode 100644
index 000000000000..47a3e3cdcc82
--- /dev/null
+++ b/drivers/clk/imx/clk-gpr-mux.c
@@ -0,0 +1,119 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ */
+
+#define pr_fmt(fmt) "imx:clk-gpr-mux: " fmt
+
+#include <linux/module.h>
+
+#include <linux/clk-provider.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include "clk.h"
+
+struct imx_clk_gpr {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u32 mask;
+	u32 reg;
+	const u32 *mux_table;
+};
+
+static struct imx_clk_gpr *to_imx_clk_gpr(struct clk_hw *hw)
+{
+	return container_of(hw, struct imx_clk_gpr, hw);
+}
+
+static u8 imx_clk_gpr_mux_get_parent(struct clk_hw *hw)
+{
+	struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(priv->regmap, priv->reg, &val);
+	if (ret)
+		goto get_parent_err;
+
+	val &= priv->mask;
+
+	ret = clk_mux_val_to_index(hw, priv->mux_table, 0, val);
+	if (ret < 0)
+		goto get_parent_err;
+
+	return ret;
+
+get_parent_err:
+	pr_err("failed to get parent (%pe)\n", ERR_PTR(ret));
+
+	/* return some realistic non negative value. Potentially we could
+	 * give index to some dummy error parent.
+	 */
+	return 0;
+}
+
+static int imx_clk_gpr_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct imx_clk_gpr *priv = to_imx_clk_gpr(hw);
+	unsigned int val = clk_mux_index_to_val(priv->mux_table, 0, index);
+
+	return regmap_update_bits(priv->regmap, priv->reg, priv->mask, val);
+}
+
+static int imx_clk_gpr_mux_determine_rate(struct clk_hw *hw,
+					 struct clk_rate_request *req)
+{
+	return clk_mux_determine_rate_flags(hw, req, 0);
+}
+
+const struct clk_ops imx_clk_gpr_mux_ops = {
+	.get_parent = imx_clk_gpr_mux_get_parent,
+	.set_parent = imx_clk_gpr_mux_set_parent,
+	.determine_rate = imx_clk_gpr_mux_determine_rate,
+};
+
+struct clk_hw *imx_clk_gpr_mux(const char *name, const char *compatible,
+			       u32 reg, const char **parent_names,
+			       u8 num_parents, const u32 *mux_table, u32 mask)
+{
+	struct clk_init_data init  = { };
+	struct imx_clk_gpr *priv;
+	struct regmap *regmap;
+	struct clk_hw *hw;
+	int ret;
+
+	regmap = syscon_regmap_lookup_by_compatible(compatible);
+	if (IS_ERR(regmap)) {
+		pr_err("failed to find %s regmap\n", compatible);
+		return ERR_CAST(regmap);
+	}
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &imx_clk_gpr_mux_ops;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+	init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
+
+	priv->hw.init = &init;
+	priv->regmap = regmap;
+	priv->mux_table = mux_table;
+	priv->reg = reg;
+	priv->mask = mask;
+
+	hw = &priv->hw;
+	ret = clk_hw_register(NULL, &priv->hw);
+	if (ret) {
+		kfree(priv);
+		hw = ERR_PTR(ret);
+	}
+
+	return hw;
+}
diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
index 689b3ad927c0..801213109697 100644
--- a/drivers/clk/imx/clk.h
+++ b/drivers/clk/imx/clk.h
@@ -458,4 +458,9 @@  struct clk_hw *imx_clk_hw_divider_gate(const char *name, const char *parent_name
 		unsigned long flags, void __iomem *reg, u8 shift, u8 width,
 		u8 clk_divider_flags, const struct clk_div_table *table,
 		spinlock_t *lock);
+
+struct clk_hw *imx_clk_gpr_mux(const char *name, const char *compatible,
+			       u32 reg, const char **parent_names,
+			       u8 num_parents, const u32 *mux_table, u32 mask);
+
 #endif