clk: meson: add regmap clocks

Meson clock controllers need to move the classical iomem registers to
regmap. This is triggered because the HHI controllers found on the GXBB
and GXL host more than just clocks. To properly handle this, we would
like to migrate HHI to syscon. Also GXBB AO clock controller already use
regmap, AXG AO and Audio clock controllers will as well.

The purpose of this change is to provide a common structure to these
meson controllers (and possibly others) for regmap based clocks.

This change provides the basic gate, mux and divider, based on the
helpers provided by the related generic clocks

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

1 files changed, 166 insertions, 0 deletions

diff --git a/drivers/clk/meson/clk-regmap.c b/drivers/clk/meson/clk-regmap.c
new file mode 100644
index 000000000000..3645fdb62343
--- /dev/null
+++ b/drivers/clk/meson/clk-regmap.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@baylibre.com>
+
+#include "clk-regmap.h"
+
+static int clk_regmap_gate_endisable(struct clk_hw *hw, int enable)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_gate_data *gate = clk_get_regmap_gate_data(clk);
+	int set = gate->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
+
+	set ^= enable;
+
+	return regmap_update_bits(clk->map, gate->offset, BIT(gate->bit_idx),
+				  set ? BIT(gate->bit_idx) : 0);
+}
+
+static int clk_regmap_gate_enable(struct clk_hw *hw)
+{
+	return clk_regmap_gate_endisable(hw, 1);
+}
+
+static void clk_regmap_gate_disable(struct clk_hw *hw)
+{
+	clk_regmap_gate_endisable(hw, 0);
+}
+
+static int clk_regmap_gate_is_enabled(struct clk_hw *hw)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_gate_data *gate = clk_get_regmap_gate_data(clk);
+	unsigned int val;
+
+	regmap_read(clk->map, gate->offset, &val);
+	if (gate->flags & CLK_GATE_SET_TO_DISABLE)
+		val ^= BIT(gate->bit_idx);
+
+	val &= BIT(gate->bit_idx);
+
+	return val ? 1 : 0;
+}
+
+const struct clk_ops clk_regmap_gate_ops = {
+	.enable = clk_regmap_gate_enable,
+	.disable = clk_regmap_gate_disable,
+	.is_enabled = clk_regmap_gate_is_enabled,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_gate_ops);
+
+static unsigned long clk_regmap_div_recalc_rate(struct clk_hw *hw,
+						unsigned long prate)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(clk->map, div->offset, &val);
+	if (ret)
+		/* Gives a hint that something is wrong */
+		return 0;
+
+	val >>= div->shift;
+	val &= clk_div_mask(div->width);
+	return divider_recalc_rate(hw, prate, val, div->table, div->flags,
+				   div->width);
+}
+
+static long clk_regmap_div_round_rate(struct clk_hw *hw, unsigned long rate,
+				      unsigned long *prate)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
+	unsigned int val;
+	int ret;
+
+	/* if read only, just return current value */
+	if (div->flags & CLK_DIVIDER_READ_ONLY) {
+		ret = regmap_read(clk->map, div->offset, &val);
+		if (ret)
+			/* Gives a hint that something is wrong */
+			return 0;
+
+		val >>= div->shift;
+		val &= clk_div_mask(div->width);
+
+		return divider_ro_round_rate(hw, rate, prate, div->table,
+					     div->width, div->flags, val);
+	}
+
+	return divider_round_rate(hw, rate, prate, div->table, div->width,
+				  div->flags);
+}
+
+static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long parent_rate)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
+	unsigned int val;
+	int ret;
+
+	ret = divider_get_val(rate, parent_rate, div->table, div->width,
+			      div->flags);
+	if (ret < 0)
+		return ret;
+
+	val = (unsigned int)ret << div->shift;
+	return regmap_update_bits(clk->map, div->offset,
+				  clk_div_mask(div->width) << div->shift, val);
+};
+
+/* Would prefer clk_regmap_div_ro_ops but clashes with qcom */
+
+const struct clk_ops clk_regmap_divider_ops = {
+	.recalc_rate = clk_regmap_div_recalc_rate,
+	.round_rate = clk_regmap_div_round_rate,
+	.set_rate = clk_regmap_div_set_rate,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_divider_ops);
+
+const struct clk_ops clk_regmap_divider_ro_ops = {
+	.recalc_rate = clk_regmap_div_recalc_rate,
+	.round_rate = clk_regmap_div_round_rate,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_divider_ro_ops);
+
+static u8 clk_regmap_mux_get_parent(struct clk_hw *hw)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_mux_data *mux = clk_get_regmap_mux_data(clk);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(clk->map, mux->offset, &val);
+	if (ret)
+		return ret;
+
+	val >>= mux->shift;
+	val &= mux->mask;
+	return clk_mux_val_to_index(hw, mux->table, mux->flags, val);
+}
+
+static int clk_regmap_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_regmap *clk = to_clk_regmap(hw);
+	struct clk_regmap_mux_data *mux = clk_get_regmap_mux_data(clk);
+	unsigned int val = clk_mux_index_to_val(mux->table, mux->flags, index);
+
+	return regmap_update_bits(clk->map, mux->offset,
+				  mux->mask << mux->shift,
+				  val << mux->shift);
+}
+
+const struct clk_ops clk_regmap_mux_ops = {
+	.get_parent = clk_regmap_mux_get_parent,
+	.set_parent = clk_regmap_mux_set_parent,
+	.determine_rate = __clk_mux_determine_rate,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_mux_ops);
+
+const struct clk_ops clk_regmap_mux_ro_ops = {
+	.get_parent = clk_regmap_mux_get_parent,
+};
+EXPORT_SYMBOL_GPL(clk_regmap_mux_ro_ops);