[v3,2/3] clk: qcom: Add support for regmap mux-div clocks

diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 50b337a24a87..38b02a7f2da3 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -8,6 +8,7 @@  clk-qcom-y += clk-rcg2.o
 clk-qcom-y += clk-branch.o
 clk-qcom-y += clk-regmap-divider.o
 clk-qcom-y += clk-regmap-mux.o
+clk-qcom-y += clk-regmap-mux-div.o
 clk-qcom-y += reset.o
 
 obj-$(CONFIG_APQ_GCC_8084) += gcc-apq8084.o
diff --git a/drivers/clk/qcom/clk-regmap-mux-div.c b/drivers/clk/qcom/clk-regmap-mux-div.c
new file mode 100644
index 000000000000..dcf12e552651
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-mux-div.c
@@ -0,0 +1,288 @@ 
+/*
+ * Copyright (c) 2015, Linaro Limited
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/regmap.h>
+
+#include "clk-regmap-mux-div.h"
+
+#define CMD_RCGR			0x0
+#define CMD_RCGR_UPDATE			BIT(0)
+#define CMD_RCGR_DIRTY_CFG		BIT(4)
+#define CMD_RCGR_ROOT_OFF		BIT(31)
+#define CFG_RCGR			0x4
+
+static int __mux_div_update_config(struct clk_regmap_mux_div *md)
+{
+	int ret;
+	u32 val, count;
+	const char *name = clk_hw_get_name(&md->clkr.hw);
+
+	ret = regmap_update_bits(md->clkr.regmap, CMD_RCGR + md->reg_offset,
+				 CMD_RCGR_UPDATE, CMD_RCGR_UPDATE);
+	if (ret)
+		return ret;
+
+	/* Wait for update to take effect */
+	for (count = 500; count > 0; count--) {
+		ret = regmap_read(md->clkr.regmap, CMD_RCGR + md->reg_offset,
+				  &val);
+		if (ret)
+			return ret;
+		if (!(val & CMD_RCGR_UPDATE))
+			return 0;
+		udelay(1);
+	}
+
+	pr_err("%s: RCG did not update its configuration", name);
+	return -EBUSY;
+}
+
+static int __mux_div_set_src_div(struct clk_regmap_mux_div *md, u32 src_sel,
+				 u32 src_div)
+{
+	int ret;
+	u32 val, mask;
+
+	val = (src_div << md->hid_shift) | (src_sel << md->src_shift);
+	mask = ((BIT(md->hid_width) - 1) << md->hid_shift) |
+	       ((BIT(md->src_width) - 1) << md->src_shift);
+
+	ret = regmap_update_bits(md->clkr.regmap, CFG_RCGR + md->reg_offset,
+				 mask, val);
+	if (ret)
+		return ret;
+
+	return __mux_div_update_config(md);
+}
+
+static void __mux_div_get_src_div(struct clk_regmap_mux_div *md, u32 *src_sel,
+				  u32 *src_div)
+{
+	u32 val, div, src;
+	const char *name = clk_hw_get_name(&md->clkr.hw);
+
+	regmap_read(md->clkr.regmap, CMD_RCGR + md->reg_offset, &val);
+
+	if (val & CMD_RCGR_DIRTY_CFG) {
+		pr_err("%s: RCG configuration is pending\n", name);
+		return;
+	}
+
+	regmap_read(md->clkr.regmap, CFG_RCGR + md->reg_offset, &val);
+	src = (val >> md->src_shift);
+	src &= BIT(md->src_width) - 1;
+	*src_sel = src;
+
+	div = (val >> md->hid_shift);
+	div &= BIT(md->hid_width) - 1;
+	*src_div = div;
+}
+
+static int mux_div_enable(struct clk_hw *hw)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	return __mux_div_set_src_div(md, md->src_sel, md->div);
+}
+
+static inline bool is_better_rate(unsigned long req, unsigned long best,
+				  unsigned long new)
+{
+	return (req <= new && new < best) || (best < req && best < new);
+}
+
+static int mux_div_determine_rate(struct clk_hw *hw,
+				  struct clk_rate_request *req)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	unsigned int i, div, max_div;
+	unsigned long actual_rate, best_rate = 0;
+	unsigned long req_rate = req->rate;
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
+		unsigned long parent_rate = clk_hw_get_rate(parent);
+
+		max_div = BIT(md->hid_width) - 1;
+		for (div = 1; div < max_div; div++) {
+			parent_rate = mult_frac(req_rate, div, 2);
+			parent_rate = clk_hw_round_rate(parent, parent_rate);
+			actual_rate = mult_frac(parent_rate, 2, div);
+
+			if (is_better_rate(req_rate, best_rate, actual_rate)) {
+				best_rate = actual_rate;
+				req->rate = best_rate;
+				req->best_parent_rate = parent_rate;
+				req->best_parent_hw = parent;
+			}
+
+			if (actual_rate < req_rate || best_rate <= req_rate)
+				break;
+		}
+	}
+
+	if (!best_rate)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int __mux_div_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
+					 unsigned long prate, u32 src_sel)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	int ret, i;
+	u32 div, max_div, best_src = 0, best_div = 0;
+	unsigned long actual_rate, best_rate = 0;
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
+		unsigned long parent_rate = clk_hw_get_rate(parent);
+
+		max_div = BIT(md->hid_width) - 1;
+		for (div = 1; div < max_div; div++) {
+			parent_rate = mult_frac(rate, div, 2);
+			parent_rate = clk_hw_round_rate(parent, parent_rate);
+			actual_rate = mult_frac(parent_rate, 2, div);
+
+			if (is_better_rate(rate, best_rate, actual_rate)) {
+				best_rate = actual_rate;
+				best_src = md->parent_map[i].cfg;
+				best_div = div - 1;
+			}
+
+			if (actual_rate < rate || best_rate <= rate)
+				break;
+		}
+	}
+
+	ret = __mux_div_set_src_div(md, best_src, best_div);
+	if (!ret) {
+		md->div = best_div;
+		md->src_sel = best_src;
+	}
+
+	return ret;
+}
+
+static u8 mux_div_get_parent(struct clk_hw *hw)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	const char *name = clk_hw_get_name(hw);
+	u32 i, div, src;
+
+	__mux_div_get_src_div(md, &src, &div);
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++)
+		if (src == md->parent_map[i].cfg)
+			return i;
+
+	pr_err("%s: Can't find parent %d\n", name, src);
+	return 0;
+}
+
+static int mux_div_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	return __mux_div_set_src_div(md, md->parent_map[index].cfg, md->div);
+}
+
+static int mux_div_set_rate(struct clk_hw *hw,
+			    unsigned long rate, unsigned long prate)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	return __mux_div_set_rate_and_parent(hw, rate, prate, md->src_sel);
+}
+
+static int mux_div_set_rate_and_parent(struct clk_hw *hw,  unsigned long rate,
+				       unsigned long prate, u8 index)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	return __mux_div_set_rate_and_parent(hw, rate, prate,
+					     md->parent_map[index].cfg);
+}
+
+static unsigned long mux_div_recalc_rate(struct clk_hw *hw, unsigned long prate)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	u32 div, src;
+	int i, num_parents = clk_hw_get_num_parents(hw);
+	const char *name = clk_hw_get_name(hw);
+
+	__mux_div_get_src_div(md, &src, &div);
+	for (i = 0; i < num_parents; i++)
+		if (src == md->parent_map[i].cfg) {
+			struct clk_hw *p = clk_hw_get_parent_by_index(hw, i);
+			unsigned long parent_rate = clk_hw_get_rate(p);
+
+			return mult_frac(parent_rate, 2, div + 1);
+		}
+
+	pr_err("%s: Can't find parent %d\n", name, src);
+	return 0;
+}
+
+static struct clk_hw *mux_div_get_safe_parent(struct clk_hw *hw,
+					      unsigned long *safe_freq)
+{
+	int i;
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+
+	if (md->safe_freq)
+		*safe_freq = md->safe_freq;
+
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++)
+		if (md->safe_src == md->parent_map[i].cfg)
+			break;
+
+	return clk_hw_get_parent_by_index(hw, i);
+}
+
+static void mux_div_disable(struct clk_hw *hw)
+{
+	struct clk_regmap_mux_div *md = to_clk_regmap_mux_div(hw);
+	struct clk_hw *parent;
+	u32 div;
+
+	if (!md->safe_freq || !md->safe_src)
+		return;
+
+	parent = mux_div_get_safe_parent(hw, &md->safe_freq);
+	div = divider_get_val(md->safe_freq, clk_get_rate(parent->clk), NULL,
+			      md->hid_width, CLK_DIVIDER_ROUND_CLOSEST);
+	div = 2 * div + 1;
+
+	__mux_div_set_src_div(md, md->safe_src, div);
+}
+
+const struct clk_ops clk_regmap_mux_div_ops = {
+	.enable = mux_div_enable,
+	.disable = mux_div_disable,
+	.get_parent = mux_div_get_parent,
+	.set_parent = mux_div_set_parent,
+	.set_rate = mux_div_set_rate,
+	.set_rate_and_parent = mux_div_set_rate_and_parent,
+	.determine_rate = mux_div_determine_rate,
+	.recalc_rate = mux_div_recalc_rate,
+	.get_safe_parent = mux_div_get_safe_parent,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_mux_div_ops);
diff --git a/drivers/clk/qcom/clk-regmap-mux-div.h b/drivers/clk/qcom/clk-regmap-mux-div.h
new file mode 100644
index 000000000000..7610a0e4abd7
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-mux-div.h
@@ -0,0 +1,63 @@ 
+/*
+ * Copyright (c) 2015, Linaro Limited
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __QCOM_CLK_REGMAP_MUX_DIV_H__
+#define __QCOM_CLK_REGMAP_MUX_DIV_H__
+
+#include <linux/clk-provider.h>
+#include "clk-regmap.h"
+#include "clk-rcg.h"
+
+/**
+ * struct mux_div_clk - combined mux/divider clock
+ * @reg_offset: offset of the mux/divider register
+ * @hid_width:	number of bits in half integer divider
+ * @hid_shift:	lowest bit of hid value field
+ * @src_width:	number of bits in source select
+ * @src_shift:	lowest bit of source select field
+ * @div:	the divider raw configuration value
+ * @src_sel:	the mux index which will be used if the clock is enabled
+ * @safe_src:	the safe source mux index for this clock
+ * @safe_freq:	When switching rates from A to B, the mux div clock will
+ *		instead switch from A -> safe_freq -> B. This allows the
+ *		mux_div clock to change rates while enabled, even if this
+ *		behavior is not supported by the parent clocks.
+ *		If changing the rate of parent A also causes the rate of
+ *		parent B to change, then safe_freq must be defined.
+ *		safe_freq is expected to have a source clock which is always
+ *		on and runs at only one rate.
+ * @parent_map:	pointer to parent_map struct
+ * @clkr:	handle between common and hardware-specific interfaces
+ */
+
+struct clk_regmap_mux_div {
+	u32				reg_offset;
+	u32				hid_width;
+	u32				hid_shift;
+	u32				src_width;
+	u32				src_shift;
+	u32				div;
+	u32				src_sel;
+	u32				safe_src;
+	unsigned long			safe_freq;
+	const struct parent_map		*parent_map;
+	struct clk_regmap		clkr;
+};
+
+#define to_clk_regmap_mux_div(_hw) \
+	container_of(to_clk_regmap(_hw), struct clk_regmap_mux_div, clkr)
+
+extern const struct clk_ops clk_regmap_mux_div_ops;
+
+#endif