clk: imx: add imx7ulp composite clk support

The imx composite clk is designed for Peripheral Clock Control (PCC)
module observed in IMX ULP SoC series.

NOTE pcc can only be operated when clk is gated.

Cc: Stephen Boyd <[e-mail]>
Cc: Michael Turquette <[e-mail]>
Cc: Shawn Guo <[e-mail]>
Cc: Anson Huang <[e-mail]>
Cc: Bai Ping <[e-mail]>
Signed-off-by: Dong Aisheng <[e-mail]>
[[e-mail]: Include clk.h for sparse warnings]
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/imx/Makefile

···
 	clk.o \
 	clk-busy.o \
 	clk-cpu.o \
+	clk-composite-7ulp.o \
 	clk-divider-gate.o \
 	clk-fixup-div.o \
 	clk-fixup-mux.o \

drivers/clk/imx/clk-composite-7ulp.c

···
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Copyright 2017~2018 NXP
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+#include "clk.h"
+
+#define PCG_PCS_SHIFT	24
+#define PCG_PCS_MASK	0x7
+#define PCG_CGC_SHIFT	30
+#define PCG_FRAC_SHIFT	3
+#define PCG_FRAC_WIDTH	1
+#define PCG_FRAC_MASK	BIT(3)
+#define PCG_PCD_SHIFT	0
+#define PCG_PCD_WIDTH	3
+#define PCG_PCD_MASK	0x7
+
+struct clk_hw *imx7ulp_clk_composite(const char *name,
+				     const char * const *parent_names,
+				     int num_parents, bool mux_present,
+				     bool rate_present, bool gate_present,
+				     void __iomem *reg)
+{
+	struct clk_hw *mux_hw = NULL, *fd_hw = NULL, *gate_hw = NULL;
+	struct clk_fractional_divider *fd = NULL;
+	struct clk_gate *gate = NULL;
+	struct clk_mux *mux = NULL;
+	struct clk_hw *hw;
+
+	if (mux_present) {
+		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+		if (!mux)
+			return ERR_PTR(-ENOMEM);
+		mux_hw = &mux->hw;
+		mux->reg = reg;
+		mux->shift = PCG_PCS_SHIFT;
+		mux->mask = PCG_PCS_MASK;
+	}
+
+	if (rate_present) {
+		fd = kzalloc(sizeof(*fd), GFP_KERNEL);
+		if (!fd) {
+			kfree(mux);
+			return ERR_PTR(-ENOMEM);
+		}
+		fd_hw = &fd->hw;
+		fd->reg = reg;
+		fd->mshift = PCG_FRAC_SHIFT;
+		fd->mwidth = PCG_FRAC_WIDTH;
+		fd->mmask  = PCG_FRAC_MASK;
+		fd->nshift = PCG_PCD_SHIFT;
+		fd->nwidth = PCG_PCD_WIDTH;
+		fd->nmask = PCG_PCD_MASK;
+		fd->flags = CLK_FRAC_DIVIDER_ZERO_BASED;
+	}
+
+	if (gate_present) {
+		gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+		if (!gate) {
+			kfree(mux);
+			kfree(fd);
+			return ERR_PTR(-ENOMEM);
+		}
+		gate_hw = &gate->hw;
+		gate->reg = reg;
+		gate->bit_idx = PCG_CGC_SHIFT;
+	}
+
+	hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
+				       mux_hw, &clk_mux_ops, fd_hw,
+				       &clk_fractional_divider_ops, gate_hw,
+				       &clk_gate_ops, CLK_SET_RATE_GATE |
+				       CLK_SET_PARENT_GATE);
+	if (IS_ERR(hw)) {
+		kfree(mux);
+		kfree(fd);
+		kfree(gate);
+	}
+
+	return hw;
+}

drivers/clk/imx/clk.h

···
 			     u8 width, void __iomem *busy_reg, u8 busy_shift,
 			     const char **parent_names, int num_parents);
 
+struct clk_hw *imx7ulp_clk_composite(const char *name,
+				     const char * const *parent_names,
+				     int num_parents, bool mux_present,
+				     bool rate_present, bool gate_present,
+				     void __iomem *reg);
+
 struct clk *imx_clk_fixup_divider(const char *name, const char *parent,
 				  void __iomem *reg, u8 shift, u8 width,
 				  void (*fixup)(u32 *val));