clk: qcom: Add simple regmap based muxes

Add support for muxes that use regmap instead of readl/writel
directly. We don't support as many features as clk-mux.c, but
this is good enough to support getting and setting parents.
Adding a table based lookup can be added in the future if needed.

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, 89 insertions, 0 deletions

diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index ed8976e87c0b..f5e5607f3965 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -7,6 +7,7 @@ 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 += clk-regmap-mux.o
 clk-qcom-y += reset.o
 
 obj-$(CONFIG_APQ_GCC_8084) += gcc-apq8084.o
diff --git a/drivers/clk/qcom/clk-regmap-mux.c b/drivers/clk/qcom/clk-regmap-mux.c
new file mode 100644
index 000000000000..cae3071f384c
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-mux.c
@@ -0,0 +1,59 @@
+/*
+ * 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-mux.h"
+
+static inline struct clk_regmap_mux *to_clk_regmap_mux(struct clk_hw *hw)
+{
+        return container_of(to_clk_regmap(hw), struct clk_regmap_mux, clkr);
+}
+
+static u8 mux_get_parent(struct clk_hw *hw)
+{
+        struct clk_regmap_mux *mux = to_clk_regmap_mux(hw);
+        struct clk_regmap *clkr = to_clk_regmap(hw);
+        unsigned int mask = GENMASK(mux->width - 1, 0);
+        unsigned int val;
+
+        regmap_read(clkr->regmap, mux->reg, &val);
+
+        val >>= mux->shift;
+        val &= mask;
+
+        return val;
+}
+
+static int mux_set_parent(struct clk_hw *hw, u8 index)
+{
+        struct clk_regmap_mux *mux = to_clk_regmap_mux(hw);
+        struct clk_regmap *clkr = to_clk_regmap(hw);
+        unsigned int mask = GENMASK(mux->width + mux->shift - 1, mux->shift);
+        unsigned int val;
+
+        val = index;
+        val <<= mux->shift;
+
+        return regmap_update_bits(clkr->regmap, mux->reg, mask, val);
+}
+
+const struct clk_ops clk_regmap_mux_closest_ops = {
+        .get_parent = mux_get_parent,
+        .set_parent = mux_set_parent,
+        .determine_rate = __clk_mux_determine_rate_closest,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_mux_closest_ops);
diff --git a/drivers/clk/qcom/clk-regmap-mux.h b/drivers/clk/qcom/clk-regmap-mux.h
new file mode 100644
index 000000000000..5cec76154fda
--- /dev/null
+++ b/drivers/clk/qcom/clk-regmap-mux.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_MUX_H__
+#define __QCOM_CLK_REGMAP_MUX_H__
+
+#include <linux/clk-provider.h>
+#include "clk-regmap.h"
+
+struct clk_regmap_mux {
+        u32                     reg;
+        u32                     shift;
+        u32                     width;
+        struct clk_regmap       clkr;
+};
+
+extern const struct clk_ops clk_regmap_mux_closest_ops;
+
+#endif