1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
new file mode 100644
index 00000000000..14b9f2b1d9e
--- /dev/null
+++ b/drivers/clk/clk-mux.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 DENX Software Engineering
+ * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
+ *
+ * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
+ * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
+ *
+ * Simple multiplexer clock implementation
+ */
+
+/*
+ * U-Boot CCF porting node:
+ *
+ * The Linux kernel - as of tag: 5.0-rc3 is using also the imx_clk_fixup_mux()
+ * version of CCF mux. It is used on e.g. imx6q to provide fixes (like
+ * imx_cscmr1_fixup) for broken HW.
+ *
+ * At least for IMX6Q (but NOT IMX6QP) it is important when we set the parent
+ * clock.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <malloc.h>
+#include <clk-uclass.h>
+#include <dm/device.h>
+#include <linux/clk-provider.h>
+#include <clk.h>
+#include "clk.h"
+
+#define UBOOT_DM_CLK_CCF_MUX "ccf_clk_mux"
+
+int clk_mux_val_to_index(struct clk *clk, u32 *table, unsigned int flags,
+			 unsigned int val)
+{
+	struct clk_mux *mux = to_clk_mux(clk);
+	int num_parents = mux->num_parents;
+
+	if (table) {
+		int i;
+
+		for (i = 0; i < num_parents; i++)
+			if (table[i] == val)
+				return i;
+		return -EINVAL;
+	}
+
+	if (val && (flags & CLK_MUX_INDEX_BIT))
+		val = ffs(val) - 1;
+
+	if (val && (flags & CLK_MUX_INDEX_ONE))
+		val--;
+
+	if (val >= num_parents)
+		return -EINVAL;
+
+	return val;
+}
+
+static u8 clk_mux_get_parent(struct clk *clk)
+{
+	struct clk_mux *mux = to_clk_mux(clk);
+	u32 val;
+
+	val = readl(mux->reg) >> mux->shift;
+	val &= mux->mask;
+
+	return clk_mux_val_to_index(clk, mux->table, mux->flags, val);
+}
+
+const struct clk_ops clk_mux_ops = {
+		.get_rate = clk_generic_get_rate,
+};
+
+struct clk *clk_hw_register_mux_table(struct device *dev, const char *name,
+		const char * const *parent_names, u8 num_parents,
+		unsigned long flags,
+		void __iomem *reg, u8 shift, u32 mask,
+		u8 clk_mux_flags, u32 *table)
+{
+	struct clk_mux *mux;
+	struct clk *clk;
+	u8 width = 0;
+	int ret;
+
+	if (clk_mux_flags & CLK_MUX_HIWORD_MASK) {
+		width = fls(mask) - ffs(mask) + 1;
+		if (width + shift > 16) {
+			pr_err("mux value exceeds LOWORD field\n");
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	/* allocate the mux */
+	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+	if (!mux)
+		return ERR_PTR(-ENOMEM);
+
+	/* U-boot specific assignments */
+	mux->parent_names = parent_names;
+	mux->num_parents = num_parents;
+
+	/* struct clk_mux assignments */
+	mux->reg = reg;
+	mux->shift = shift;
+	mux->mask = mask;
+	mux->flags = clk_mux_flags;
+	mux->table = table;
+
+	clk = &mux->clk;
+
+	/*
+	 * Read the current mux setup - so we assign correct parent.
+	 *
+	 * Changing parent would require changing internals of udevice struct
+	 * for the corresponding clock (to do that define .set_parent() method.
+	 */
+	ret = clk_register(clk, UBOOT_DM_CLK_CCF_MUX, name,
+			   parent_names[clk_mux_get_parent(clk)]);
+	if (ret) {
+		kfree(mux);
+		return ERR_PTR(ret);
+	}
+
+	return clk;
+}
+
+struct clk *clk_register_mux_table(struct device *dev, const char *name,
+		const char * const *parent_names, u8 num_parents,
+		unsigned long flags,
+		void __iomem *reg, u8 shift, u32 mask,
+		u8 clk_mux_flags, u32 *table)
+{
+	struct clk *clk;
+
+	clk = clk_hw_register_mux_table(dev, name, parent_names, num_parents,
+				       flags, reg, shift, mask, clk_mux_flags,
+				       table);
+	if (IS_ERR(clk))
+		return ERR_CAST(clk);
+	return clk;
+}
+
+struct clk *clk_register_mux(struct device *dev, const char *name,
+		const char * const *parent_names, u8 num_parents,
+		unsigned long flags,
+		void __iomem *reg, u8 shift, u8 width,
+		u8 clk_mux_flags)
+{
+	u32 mask = BIT(width) - 1;
+
+	return clk_register_mux_table(dev, name, parent_names, num_parents,
+				      flags, reg, shift, mask, clk_mux_flags,
+				      NULL);
+}
+
+U_BOOT_DRIVER(ccf_clk_mux) = {
+	.name	= UBOOT_DM_CLK_CCF_MUX,
+	.id	= UCLASS_CLK,
+	.ops	= &clk_mux_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};