clk: visconti: Add support common clock driver and reset driver

Add support for common interface of the common clock and reset driver
for Toshiba Visconti5 and its SoC, TMPV7708. The PIPLLCT provides the PLL,
and the PISMU provides clock and reset functionality.
Each drivers are provided in this patch.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Link: https://lore.kernel.org/r/20211025031038.4180686-4-nobuhiro1.iwamatsu@toshiba.co.jp
[sboyd@kernel.org: Add bitfield.h include to pll.c]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

1 files changed, 206 insertions, 0 deletions

diff --git a/drivers/clk/visconti/clkc.c b/drivers/clk/visconti/clkc.c
new file mode 100644
index 000000000000..56a8a4ffebca
--- /dev/null
+++ b/drivers/clk/visconti/clkc.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Toshiba Visconti clock controller
+ *
+ * Copyright (c) 2021 TOSHIBA CORPORATION
+ * Copyright (c) 2021 Toshiba Electronic Devices & Storage Corporation
+ *
+ * Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "clkc.h"
+
+static inline struct visconti_clk_gate *to_visconti_clk_gate(struct clk_hw *hw)
+{
+	return container_of(hw, struct visconti_clk_gate, hw);
+}
+
+static int visconti_gate_clk_is_enabled(struct clk_hw *hw)
+{
+	struct visconti_clk_gate *gate = to_visconti_clk_gate(hw);
+	u32 clk = BIT(gate->ck_idx);
+	u32 val;
+
+	regmap_read(gate->regmap, gate->ckon_offset, &val);
+	return (val & clk) ? 1 : 0;
+}
+
+static void visconti_gate_clk_disable(struct clk_hw *hw)
+{
+	struct visconti_clk_gate *gate = to_visconti_clk_gate(hw);
+	u32 clk = BIT(gate->ck_idx);
+	unsigned long flags;
+
+	spin_lock_irqsave(gate->lock, flags);
+
+	if (!visconti_gate_clk_is_enabled(hw)) {
+		spin_unlock_irqrestore(gate->lock, flags);
+		return;
+	}
+
+	regmap_update_bits(gate->regmap, gate->ckoff_offset, clk, clk);
+	spin_unlock_irqrestore(gate->lock, flags);
+}
+
+static int visconti_gate_clk_enable(struct clk_hw *hw)
+{
+	struct visconti_clk_gate *gate = to_visconti_clk_gate(hw);
+	u32 clk = BIT(gate->ck_idx);
+	unsigned long flags;
+
+	spin_lock_irqsave(gate->lock, flags);
+	regmap_update_bits(gate->regmap, gate->ckon_offset, clk, clk);
+	spin_unlock_irqrestore(gate->lock, flags);
+
+	return 0;
+}
+
+static const struct clk_ops visconti_clk_gate_ops = {
+	.enable = visconti_gate_clk_enable,
+	.disable = visconti_gate_clk_disable,
+	.is_enabled = visconti_gate_clk_is_enabled,
+};
+
+static struct clk_hw *visconti_clk_register_gate(struct device *dev,
+						 const char *name,
+						 const char *parent_name,
+						 struct regmap *regmap,
+						 const struct visconti_clk_gate_table *clks,
+						 u32	rson_offset,
+						 u32	rsoff_offset,
+						 u8	rs_idx,
+						 spinlock_t *lock)
+{
+	struct visconti_clk_gate *gate;
+	struct clk_parent_data *pdata;
+	struct clk_init_data init;
+	struct clk_hw *hw;
+	int ret;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	pdata->name = pdata->fw_name = parent_name;
+
+	gate = devm_kzalloc(dev, sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &visconti_clk_gate_ops;
+	init.flags = clks->flags;
+	init.parent_data = pdata;
+	init.num_parents = 1;
+
+	gate->regmap = regmap;
+	gate->ckon_offset = clks->ckon_offset;
+	gate->ckoff_offset = clks->ckoff_offset;
+	gate->ck_idx = clks->ck_idx;
+	gate->rson_offset = rson_offset;
+	gate->rsoff_offset = rsoff_offset;
+	gate->rs_idx = rs_idx;
+	gate->lock = lock;
+	gate->hw.init = &init;
+
+	hw = &gate->hw;
+	ret = devm_clk_hw_register(dev, hw);
+	if (ret)
+		hw = ERR_PTR(ret);
+
+	return hw;
+}
+
+int visconti_clk_register_gates(struct visconti_clk_provider *ctx,
+				const struct visconti_clk_gate_table *clks,
+				int num_gate,
+				const struct visconti_reset_data *reset,
+				spinlock_t *lock)
+{
+	struct device *dev = ctx->dev;
+	int i;
+
+	for (i = 0; i < num_gate; i++) {
+		const char *parent_div_name = clks[i].parent_data[0].name;
+		struct clk_parent_data *pdata;
+		u32 rson_offset, rsoff_offset;
+		struct clk_hw *gate_clk;
+		struct clk_hw *div_clk;
+		char *dev_name;
+		u8 rs_idx;
+
+		pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+		if (!pdata)
+			return -ENOMEM;
+
+		dev_name = devm_kasprintf(dev, GFP_KERNEL, "%s_div", clks[i].name);
+		if (!dev_name)
+			return -ENOMEM;
+
+		if (clks[i].rs_id >= 0) {
+			rson_offset = reset[clks[i].rs_id].rson_offset;
+			rsoff_offset = reset[clks[i].rs_id].rsoff_offset;
+			rs_idx = reset[clks[i].rs_id].rs_idx;
+		} else {
+			rson_offset = rsoff_offset = rs_idx = -1;
+		}
+
+		div_clk = devm_clk_hw_register_fixed_factor(dev,
+							    dev_name,
+							    parent_div_name,
+							    0, 1,
+							    clks[i].div);
+		if (IS_ERR(div_clk))
+			return PTR_ERR(div_clk);
+
+		gate_clk = visconti_clk_register_gate(dev,
+						      clks[i].name,
+						      dev_name,
+						      ctx->regmap,
+						      &clks[i],
+						      rson_offset,
+						      rsoff_offset,
+						      rs_idx,
+						      lock);
+		if (IS_ERR(gate_clk)) {
+			dev_err(dev, "%s: failed to register clock %s\n",
+				__func__, clks[i].name);
+			return PTR_ERR(gate_clk);
+		}
+
+		ctx->clk_data.hws[clks[i].id] = gate_clk;
+	}
+
+	return 0;
+}
+
+struct visconti_clk_provider *visconti_init_clk(struct device *dev,
+						struct regmap *regmap,
+						unsigned long nr_clks)
+{
+	struct visconti_clk_provider *ctx;
+	int i;
+
+	ctx = devm_kzalloc(dev, struct_size(ctx, clk_data.hws, nr_clks), GFP_KERNEL);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < nr_clks; ++i)
+		ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
+	ctx->clk_data.num = nr_clks;
+
+	ctx->dev = dev;
+	ctx->regmap = regmap;
+
+	return ctx;
+}