clk: qcom: Add support for regmap divider clocks

Add support for dividers that use regmap instead of readl/writel.

Signed-off-by: Josh Cartwright <[e-mail]>
Signed-off-by: Rajendra Nayak <[e-mail]>
[[e-mail]: Switch to using generic divider code, drop
enable/disable, reword commit text]
Signed-off-by: Stephen Boyd <[e-mail]>
Tested-by: Kenneth Westfield <[e-mail]>
Signed-off-by: Michael Turquette <[e-mail]>

drivers/clk/qcom/Makefile

···
 clk-qcom-y += clk-rcg.o
 clk-qcom-y += clk-rcg2.o
 clk-qcom-y += clk-branch.o
+clk-qcom-y += clk-regmap-divider.o
 clk-qcom-y += reset.o
 
 obj-$(CONFIG_APQ_GCC_8084) += gcc-apq8084.o

drivers/clk/qcom/clk-regmap-divider.c

···
+/*
+ * 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/kernel.h>
+#include <linux/bitops.h>
+#include <linux/regmap.h>
+#include <linux/export.h>
+
+#include "clk-regmap-divider.h"
+
+static inline struct clk_regmap_div *to_clk_regmap_div(struct clk_hw *hw)
+{
+	return container_of(to_clk_regmap(hw), struct clk_regmap_div, clkr);
+}
+
+static long div_round_rate(struct clk_hw *hw, unsigned long rate,
+			   unsigned long *prate)
+{
+	struct clk_regmap_div *divider = to_clk_regmap_div(hw);
+
+	return divider_round_rate(hw, rate, prate, NULL, divider->width,
+				  CLK_DIVIDER_ROUND_CLOSEST);
+}
+
+static int div_set_rate(struct clk_hw *hw, unsigned long rate,
+			unsigned long parent_rate)
+{
+	struct clk_regmap_div *divider = to_clk_regmap_div(hw);
+	struct clk_regmap *clkr = &divider->clkr;
+	u32 div;
+
+	div = divider_get_val(rate, parent_rate, NULL, divider->width,
+			      CLK_DIVIDER_ROUND_CLOSEST);
+
+	return regmap_update_bits(clkr->regmap, divider->reg,
+				  (BIT(divider->width) - 1) << divider->shift,
+				  div << divider->shift);
+}
+
+static unsigned long div_recalc_rate(struct clk_hw *hw,
+				     unsigned long parent_rate)
+{
+	struct clk_regmap_div *divider = to_clk_regmap_div(hw);
+	struct clk_regmap *clkr = &divider->clkr;
+	u32 div;
+
+	regmap_read(clkr->regmap, divider->reg, &div);
+	div >>= divider->shift;
+	div &= BIT(divider->width) - 1;
+
+	return divider_recalc_rate(hw, parent_rate, div, NULL,
+				   CLK_DIVIDER_ROUND_CLOSEST);
+}
+
+const struct clk_ops clk_regmap_div_ops = {
+	.round_rate = div_round_rate,
+	.set_rate = div_set_rate,
+	.recalc_rate = div_recalc_rate,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_div_ops);

drivers/clk/qcom/clk-regmap-divider.h

···
+/*
+ * 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_DIVIDER_H__
+#define __QCOM_CLK_REGMAP_DIVIDER_H__
+
+#include <linux/clk-provider.h>
+#include "clk-regmap.h"
+
+struct clk_regmap_div {
+	u32			reg;
+	u32			shift;
+	u32			width;
+	struct clk_regmap	clkr;
+};
+
+extern const struct clk_ops clk_regmap_div_ops;
+
+#endif