clk: qcom: Add support for regmap divider clocks

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

Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
[sboyd@codeaurora.org: Switch to using generic divider code, drop
enable/disable, reword commit text]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Kenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

3 files changed, 100 insertions, 0 deletions

diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 783cfb24faa4..ed8976e87c0b 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -6,6 +6,7 @@ clk-qcom-y += clk-pll.o
 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
diff --git a/drivers/clk/qcom/clk-regmap-divider.c b/drivers/clk/qcom/clk-regmap-divider.c
new file mode 100644
index 000000000000..53484912301e
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-divider.c
@@ -0,0 +1,70 @@
+/*
+ * 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);
diff --git a/drivers/clk/qcom/clk-regmap-divider.h b/drivers/clk/qcom/clk-regmap-divider.h
new file mode 100644
index 000000000000..fc4492e3a827
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-divider.h
@@ -0,0 +1,29 @@
+/*
+ * 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