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, 340 insertions, 0 deletions

diff --git a/drivers/clk/visconti/pll.c b/drivers/clk/visconti/pll.c
new file mode 100644
index 000000000000..3b6e88bb73d5
--- /dev/null
+++ b/drivers/clk/visconti/pll.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Toshiba Visconti PLL driver
+ *
+ * Copyright (c) 2021 TOSHIBA CORPORATION
+ * Copyright (c) 2021 Toshiba Electronic Devices & Storage Corporation
+ *
+ * Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include "pll.h"
+
+struct visconti_pll {
+	struct clk_hw	hw;
+	void __iomem	*pll_base;
+	spinlock_t	*lock;
+	unsigned long flags;
+	const struct visconti_pll_rate_table *rate_table;
+	size_t rate_count;
+	struct visconti_pll_provider *ctx;
+};
+
+#define PLL_CONF_REG		0x0000
+#define PLL_CTRL_REG		0x0004
+#define PLL_FRACMODE_REG	0x0010
+#define PLL_INTIN_REG		0x0014
+#define PLL_FRACIN_REG		0x0018
+#define PLL_REFDIV_REG		0x001c
+#define PLL_POSTDIV_REG		0x0020
+
+#define PLL_CONFIG_SEL		BIT(0)
+#define PLL_PLLEN		BIT(4)
+#define PLL_BYPASS		BIT(16)
+#define PLL_INTIN_MASK		GENMASK(11, 0)
+#define PLL_FRACIN_MASK		GENMASK(23, 0)
+#define PLL_REFDIV_MASK		GENMASK(5, 0)
+#define PLL_POSTDIV_MASK	GENMASK(2, 0)
+
+#define PLL0_FRACMODE_DACEN	BIT(4)
+#define PLL0_FRACMODE_DSMEN	BIT(0)
+
+#define PLL_CREATE_FRACMODE(table) (table->dacen << 4 | table->dsmen)
+#define PLL_CREATE_OSTDIV(table) (table->postdiv2 << 4 | table->postdiv1)
+
+static inline struct visconti_pll *to_visconti_pll(struct clk_hw *hw)
+{
+	return container_of(hw, struct visconti_pll, hw);
+}
+
+static void visconti_pll_get_params(struct visconti_pll *pll,
+				    struct visconti_pll_rate_table *rate_table)
+{
+	u32 postdiv, val;
+
+	val = readl(pll->pll_base + PLL_FRACMODE_REG);
+
+	rate_table->dacen = FIELD_GET(PLL0_FRACMODE_DACEN, val);
+	rate_table->dsmen = FIELD_GET(PLL0_FRACMODE_DSMEN, val);
+
+	rate_table->fracin = readl(pll->pll_base + PLL_FRACIN_REG) & PLL_FRACIN_MASK;
+	rate_table->intin = readl(pll->pll_base + PLL_INTIN_REG) & PLL_INTIN_MASK;
+	rate_table->refdiv = readl(pll->pll_base + PLL_REFDIV_REG) & PLL_REFDIV_MASK;
+
+	postdiv = readl(pll->pll_base + PLL_POSTDIV_REG);
+	rate_table->postdiv1 = postdiv & PLL_POSTDIV_MASK;
+	rate_table->postdiv2 = (postdiv >> 4) & PLL_POSTDIV_MASK;
+}
+
+static const struct visconti_pll_rate_table *visconti_get_pll_settings(struct visconti_pll *pll,
+								       unsigned long rate)
+{
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	int i;
+
+	for (i = 0; i < pll->rate_count; i++)
+		if (rate == rate_table[i].rate)
+			return &rate_table[i];
+
+	return NULL;
+}
+
+static unsigned long visconti_get_pll_rate_from_data(struct visconti_pll *pll,
+						     const struct visconti_pll_rate_table *rate)
+{
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	int i;
+
+	for (i = 0; i < pll->rate_count; i++)
+		if (memcmp(&rate_table[i].dacen, &rate->dacen,
+			sizeof(*rate) - sizeof(unsigned long)) == 0)
+			return rate_table[i].rate;
+
+	/* set default */
+	return rate_table[0].rate;
+}
+
+static long visconti_pll_round_rate(struct clk_hw *hw,
+				    unsigned long rate, unsigned long *prate)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	int i;
+
+	/* Assumming rate_table is in descending order */
+	for (i = 0; i < pll->rate_count; i++)
+		if (rate >= rate_table[i].rate)
+			return rate_table[i].rate;
+
+	/* return minimum supported value */
+	return rate_table[i - 1].rate;
+}
+
+static unsigned long visconti_pll_recalc_rate(struct clk_hw *hw,
+					      unsigned long parent_rate)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	struct visconti_pll_rate_table rate_table;
+
+	memset(&rate_table, 0, sizeof(rate_table));
+	visconti_pll_get_params(pll, &rate_table);
+
+	return visconti_get_pll_rate_from_data(pll, &rate_table);
+}
+
+static int visconti_pll_set_params(struct visconti_pll *pll,
+				   const struct visconti_pll_rate_table *rate_table)
+{
+	writel(PLL_CREATE_FRACMODE(rate_table), pll->pll_base + PLL_FRACMODE_REG);
+	writel(PLL_CREATE_OSTDIV(rate_table), pll->pll_base + PLL_POSTDIV_REG);
+	writel(rate_table->intin, pll->pll_base + PLL_INTIN_REG);
+	writel(rate_table->fracin, pll->pll_base + PLL_FRACIN_REG);
+	writel(rate_table->refdiv, pll->pll_base + PLL_REFDIV_REG);
+
+	return 0;
+}
+
+static int visconti_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long parent_rate)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	const struct visconti_pll_rate_table *rate_table;
+
+	rate_table = visconti_get_pll_settings(pll, rate);
+	if (!rate_table)
+		return -EINVAL;
+
+	return visconti_pll_set_params(pll, rate_table);
+}
+
+static int visconti_pll_is_enabled(struct clk_hw *hw)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	u32 reg;
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+
+	return (reg & PLL_PLLEN);
+}
+
+static int visconti_pll_enable(struct clk_hw *hw)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	const struct visconti_pll_rate_table *rate_table = pll->rate_table;
+	unsigned long flags;
+	u32 reg;
+
+	if (visconti_pll_is_enabled(hw))
+		return 0;
+
+	spin_lock_irqsave(pll->lock, flags);
+
+	writel(PLL_CONFIG_SEL, pll->pll_base + PLL_CONF_REG);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg |= PLL_BYPASS;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	visconti_pll_set_params(pll, &rate_table[0]);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg &= ~PLL_PLLEN;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	udelay(1);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg |= PLL_PLLEN;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	udelay(40);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg &= ~PLL_BYPASS;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	spin_unlock_irqrestore(pll->lock, flags);
+
+	return 0;
+}
+
+static void visconti_pll_disable(struct clk_hw *hw)
+{
+	struct visconti_pll *pll = to_visconti_pll(hw);
+	unsigned long flags;
+	u32 reg;
+
+	if (!visconti_pll_is_enabled(hw))
+		return;
+
+	spin_lock_irqsave(pll->lock, flags);
+
+	writel(PLL_CONFIG_SEL, pll->pll_base + PLL_CONF_REG);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg |= PLL_BYPASS;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	reg = readl(pll->pll_base + PLL_CTRL_REG);
+	reg &= ~PLL_PLLEN;
+	writel(reg, pll->pll_base + PLL_CTRL_REG);
+
+	spin_unlock_irqrestore(pll->lock, flags);
+}
+
+static const struct clk_ops visconti_pll_ops = {
+	.enable = visconti_pll_enable,
+	.disable = visconti_pll_disable,
+	.is_enabled = visconti_pll_is_enabled,
+	.round_rate = visconti_pll_round_rate,
+	.recalc_rate = visconti_pll_recalc_rate,
+	.set_rate = visconti_pll_set_rate,
+};
+
+static struct clk_hw *visconti_register_pll(struct visconti_pll_provider *ctx,
+					    const char *name,
+					    const char *parent_name,
+					    int offset,
+					    const struct visconti_pll_rate_table *rate_table,
+					    spinlock_t *lock)
+{
+	struct clk_init_data init;
+	struct visconti_pll *pll;
+	struct clk *pll_clk;
+	struct clk_hw *pll_hw_clk;
+	size_t len;
+	int ret;
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.flags = CLK_IGNORE_UNUSED;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	for (len = 0; rate_table[len].rate != 0; )
+		len++;
+	pll->rate_count = len;
+	pll->rate_table = kmemdup(rate_table,
+				  pll->rate_count * sizeof(struct visconti_pll_rate_table),
+				  GFP_KERNEL);
+	WARN(!pll->rate_table, "%s: could not allocate rate table for %s\n", __func__, name);
+
+	init.ops = &visconti_pll_ops;
+	pll->hw.init = &init;
+	pll->pll_base = ctx->reg_base + offset;
+	pll->lock = lock;
+	pll->ctx = ctx;
+
+	pll_hw_clk = &pll->hw;
+	ret = clk_hw_register(NULL, &pll->hw);
+	if (ret) {
+		pr_err("failed to register pll clock %s : %ld\n", name, PTR_ERR(pll_clk));
+		kfree(pll);
+		pll_hw_clk = ERR_PTR(ret);
+	}
+
+	return pll_hw_clk;
+}
+
+static void visconti_pll_add_lookup(struct visconti_pll_provider *ctx,
+				    struct clk_hw *hw_clk,
+				    unsigned int id)
+{
+	if (ctx->clk_data.hws && id)
+		ctx->clk_data.hws[id] = hw_clk;
+}
+
+void __init visconti_register_plls(struct visconti_pll_provider *ctx,
+				   const struct visconti_pll_info *list,
+				   unsigned int nr_plls,
+				   spinlock_t *lock)
+{
+	int idx;
+
+	for (idx = 0; idx < nr_plls; idx++, list++) {
+		struct clk_hw *clk;
+
+		clk = visconti_register_pll(ctx,
+					    list->name,
+					    list->parent,
+					    list->base_reg,
+					    list->rate_table,
+					    lock);
+		if (IS_ERR(clk)) {
+			pr_err("failed to register clock %s\n", list->name);
+			continue;
+		}
+
+		visconti_pll_add_lookup(ctx, clk, list->id);
+	}
+}
+
+struct visconti_pll_provider * __init visconti_init_pll(struct device_node *np,
+							void __iomem *base,
+							unsigned long nr_plls)
+{
+	struct visconti_pll_provider *ctx;
+	int i;
+
+	ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_plls), GFP_KERNEL);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < nr_plls; ++i)
+		ctx->clk_data.hws[i] = ERR_PTR(-ENOENT);
+
+	ctx->node = np;
+	ctx->reg_base = base;
+	ctx->clk_data.num = nr_plls;
+
+	return ctx;
+}